Immunoregulation in cancer-bearing hosts. Down-regulation of gene expression and cytotoxic function in CD8+ T cells. The causes of the decreased immune responsiveness in tumor-bearing hosts are incompletely understood. The impact of a decreased immune response in cancer patients on the clinical response in immunotherapy trials has not been evaluated. The present report demonstrates a marked decrease in the therapeutic efficacy of adoptively transferred T lymphocytes obtained from murine hosts bearing tumor for greater than 30 days [late tumor-bearing mice (TBM)] as compared with normal mice and mice bearing tumor for less than 21 days (early TBM). In vitro analysis of the functions of the T lymphocytes from late TBM showed an apparently normal proliferative response to anti-CD3 and IL-2 with adequate lymphokine production from CD4+ cells, but a significant decrease in the cytotoxic function of CD8+ cells. The decreased cytotoxicity was not because of cell-mediated suppression. The expression of granzyme B mRNA was significantly delayed and decreased in magnitude in CD8+ cells from late TBM. Culture supernatants from two unrelated tumor cell lines were able to inhibit the cytotoxic activity of normal CD8+ cells in vitro. The tumor-derived suppressive factor is not transforming growth factor-beta (TGF-beta), but it has not been further characterized. The data suggest that one potential mechanism responsible for immunologic defects in patients with large tumor burdens is a tumor-induced defect that compromises the function of CD8+ effector T cells.


Influence of resistant and susceptible genotype, IL-1, and lymphoid organ on Trichinella spiralis-induced cytokine secretion. The relative importance of cell-mediated inflammatory responses and antibody-mediated responses in controlling parasitic helminth infection is debated. To study the relationship between these responses and resistance or susceptibility to primary Trichinella spiralis infection, we infected resistant AKR mice and susceptible B10.BR mice and analyzed the lymphokines IL-2, IFN-gamma, and IL-5 produced by their T cells as a function of time and lymphoid organ. IL-2-secretors occurred maximally between days 3 and 6 postinfection, whereas IL-5-secretors peaked between days 6 and 9. Previously, we found that IFN-gamma producers peaked before day 6, whereas IL-4 producers peaked between days 6 and 9. Most cytokine secretors were CD4+. The simultaneous development of IL-2- and IFN-gamma-secreting cells, and IL-4- and IL-5-secreting cells, suggests that the infection may be stimulating T cells to differentiate into cells capable of secreting specific cytokine sets, analogous to the postulated Th1 and Th2 subsets. In the spleen and mesenteric lymph nodes, cells from B10.BR mice secreted more IL-5 than cells from AKR mice, as we found previously for IL-4. For both strains, mesenteric lymph node cells produced more IL-5 than splenocytes. The AKR mesenteric lymph node cells produced more IL-2 than the B10.BR cells, but the reverse occurred in splenocytes. The AKR peripheral lymph node cells also secreted more IFN-gamma than the B10.BR cells, but the strains were equivalent for peritoneal exudate cell IFN-gamma production. Thus, the lymphoid organ microenvironment plays an important role in regulating cytokine-secreting cell development in this system. We also tested the possible regulatory role of IL-1. Exogenous rIL-1 alpha increased IFN-gamma secretion early but not late in mesenteric lymph node cells from both strains; this reflected an increased IFN-gamma-secreting cell frequency, not a change in IFN-gamma mRNA transcript level. Exogenous rIL-1 alpha did not consistently affect IL-2, IL-4, or IL-5 secretion. These data suggest that IL-1 alpha availability in vivo may regulate IFN-gamma-secreting cell development. In sum, early activation of IFN-gamma-secreting T cells in lymph nodes, with little subsequent activation of IL-4- and IL-5-secreting cells, distinguished the resistant from susceptible strain responses to T. spiralis infection, and IL-1 alpha and lymphoid organ environment influence IFN-gamma-secreting cell activation.


Cross-linking of sialophorin (CD43) induces neutrophil aggregation in a CD18-dependent and a CD18-independent way. Normal human neutrophils bound an as yet unclustered mAb designated BS-1. The Ag immunoprecipitated with BS-1 was blotted by CD43 mAb (and vice versa), and is therefore identical to the large sialoglycoprotein. The CD43 Ag expression on the neutrophil surface is decreased upon neutrophil activation with the chemoattractant FMLP or with PMA. This can be (at least partially) explained by the release of CD43+ material with an altered electrophoretic mobility into the extracellular medium of the neutrophils upon activation. Cross-linking of the CD43 Ag with BS-1 also invoked neutrophil activation by itself: F(ab)2 fragments of BS-1-induced neutrophil aggregation, in contrast to F(ab) fragments. Neither respiratory burst activity nor a significant rise in intracellular Ca2+ level or actin polymerization were observed. The transient neutrophil aggregation response was largely CD18 dependent, especially in the initial phase of homotypic clustering. However, a significant CD18-independent mechanism contributed thereafter to the neutrophil aggregation, as was further substantiated by the use of cultured T (and EBV-transformed B) cell clones of a patient with a leukocyte adhesion deficiency. CD43 is the first molecule described on neutrophils able to induce adhesive properties in a dual fashion.


Vaccination of vaccinia-naive adults with human immunodeficiency virus type 1 gp160 recombinant vaccinia virus in a blinded, controlled, randomized clinical trial. The AIDS Vaccine Clinical Trials Network. The safety and immunogenicity of a human immunodeficiency virus type 1 (HIV-1) gp160 recombinant vaccinia virus (HIVAC-1e) vaccine was evaluated in vaccinia-naive, healthy adults at low risk for acquiring HIV-1 infection. Volunteers (n = 36) were randomized to receive HIVAC-1e or control vaccinia virus at two dosages by bifurcated needle puncture at 0 and 2 months; 12 HIVAC-1e and 6 control vaccinia virus recipients received either 10(6) or 10(7) pfu/mL at each inoculation. There was no significant difference in lesion size, level of viral replication, or systemic symptoms after vaccination with HIVAC-1e or control vaccinia virus. Of 22 HIVAC-1e recipients with lesion formation, 16 developed low-titer gp160-specific antibody responses detectable by Western blot. The peak response occurred between days 70 and 120 and was still detectable at day 365 in 9 of 18 vaccinees. gp160-specific lymphoproliferative responses were detected in 5 of 10 vaccinees. Vaccination with HIVAC-1e was safe in vaccinia-naive, healthy adults and could induce both humoral and cell-mediated gp160-specific immune responses.


Quantitation of human immunodeficiency virus provirus and circulating virus: relationship with immunologic parameters. Virologic and seroimmunologic parameters were determined in 56 persons infected with human immunodeficiency virus (HIV). The provirus level varied from 10 to 100,000/10(6) CD4+ lymphocytes, and genomic HIV RNA was detectable in 39 of 56 patients at a relative concentration varying from 10 to greater than 250 copies/mL of serum. Provirus expressed as copies per 10(6) CD4+ lymphocytes and as circulating virus per milliliter of serum increased with disease progression and decrease of CD4+ cell concentration. The mean provirus concentration expressed per milliliter of blood varied little among categories of patients with various levels of CD4+ cells, but there was a progressive increase of circulating HIV genomic RNA. These virologic data suggest that during the course of HIV infection, an increasing proportion of the remaining CD4+ lymphocytes harbor the HIV genome and produce infectious virus. Finally, there was a marked correlation between increased provirus and genomic RNA concentration and three seroimmunologic markers: decrease in CD4+ cell count, p24 antigenemia, and disappearance of antibodies to HIV core antigen.


Degenerative changes in the function of neuromuscular junctions of Manduca sexta during metamorphosis. In Manduca sexta the decline in neuromuscular function during metamorphic degeneration was compared in two muscles which differed characteristically with regard to pre- and postsynaptic physiological properties. In both muscles, morphological evidence indicated that a significant number of the active zones within the population of neuromuscular junctions on a given fiber were nonfunctional. Nevertheless, the degenerating nerve terminals were able to produce an above-threshold excitatory junction potential (EJP) which was facilitated in a manner characteristic of the muscle being observed. Abnormal findings during the early stages of degeneration included a larger than normal EJP, a decline in EJP amplitude over a 20 min period even with low frequencies of stimulation, an increase in EJP duration, a decline in muscle fiber resting potential amplitude with age, a decrease or disappearance of post-tetanic potentiation and long-term facilitation, and an increased likelihood that the motor nerve would fail to conduct a stimulus. The two muscles were qualitatively similar but quantitatively different with regard to these degenerative changes. It is suggested that this combination of relatively normal function with abnormal properties might be associated with the withdrawal of glial processes from the neuromuscular junctions, changes in the cable properties associated with shrivelling of the muscle fibers, and a decline in the metabolic functions supporting both muscle fiber resting potentials and those underlying transmitter synthesis, mobilization and release.


Further analysis of nucleic acids in purified scrapie prion preparations by improved return refocusing gel electrophoresis. Although increasingly unlikely, the possibility of a scrapie-specific nucleic acid carried by infectious prion particles is still unresolved. Return refocusing gel electrophoresis was developed to detect homogeneous and heterogeneous nucleic acids extracted from highly purified scrapie prion preparations. This method was improved with respect to the size range from 13 to 1100 nucleotides (nt) over which analyses could be performed. The yield of nucleic acid, particularly of small DNA oligonucleotides and polyadenylated RNA, was determined after deproteinization and two-phase extraction. Despite extensive nuclease digestions some small polynucleotides remained. Although a scrapie-specific nucleic acid cannot be excluded, the results further define the possible characteristics of a hypothetical molecule. If homogeneous in size, such a molecule would be less than 80 nt in length at a particle-to-infectivity ratio near unity, if heterogeneous, scrapie-specific nucleic acids would have to include molecules smaller than 240 nt.


Cloning and sequencing of Puumala virus Sotkamo strain S and M RNA segments: evidence for strain variation in hantaviruses and expression of the nucleocapsid protein. The prototype Puumala virus (PV) Sotkamo strain small (S) and medium (M) RNA genome segments were amplified by the polymerase chain reaction (PCR), cloned and sequenced. The S segment is 1830 nucleotides long with an open reading frame coding for 433 amino acids. The identity to the PV Hällnäs strain was 83% at the nucleotide and 96% at the amino acid level. The M segment in the Sotkamo strain is 3616 nucleotides long and contains one open reading frame of 1148 amino acids with 83% nucleotide and 94% amino acid identity to the Hällnäs strain. Most amino acid changes were conservative and the five predicted glycosylation sites are identical. The amino acid identity to the prototype hantavirus, Hantaan virus, was 62 and 54% for S and M segments, respectively. The coding region of the S segment was further amplified by PCR, ligated to pEX vectors and expressed in Escherichia coli as a beta-galactosidase fusion protein and was seen to be specifically detected by nephropathia epidemica sera in immunoblotting.


Relationship between HOX2 homeobox gene expression and the human cytomegalovirus immediate early genes. The human embryonal carcinoma cell line NT2/D1 is known to be non-permissive for human cytomegalovirus (HCMV) but becomes permissive after being induced to differentiate by retinoic acid (RA). Because homeobox genes have been reported to be specifically activated in the RA-differentiated NT2/D1 cells, we investigated the possible correlation between expression of homeobox (HOX) 2 genes and expression of the immediate early (IE) genes of HCMV both in NT2/D1 cells and in HCMV permissive human embryonic lung (HEL) cells. HCMV infection did not induce activation of the HOX2A, HOX2E and HOX2I genes in undifferentiated NT2/D1 cells nor affect their activation in the RA-differentiated NT2/D1 cells. By in situ hybridization using a HOX2A RNA probe, HOX2A transcript-positive cells appeared as clusters in RA-differentiated NT2/D1 cells. Viral antigen-positive cells detected by immunofluorescence using an antibody specific for the IE-1 antigen of HCMV appeared as clusters among the population of cells in which the HOX2A transcript was detected. The HOX2A gene only was expressed in HEL cells, however none of the HOX2 genes was expressed in non-permissive HeLa, Raji or mouse embryonic cells. These results suggest that activation of the HOX2A may be necessary for the expression of IE genes. HCMV infection markedly increased the expression of the HOX2E gene in HEL cells in the presence, but not in the absence, of cycloheximide. Ultraviolet-inactivated HCMV also displayed this effect. On the other hand, HCMV infection suppressed expression of the HOX2A gene to some degree at the early and late phases of infection in HEL cells. Activation of the HOX2E gene by HCMV might possibly have a role in virus-induced abnormal embryogenesis.


Selective inhibition of complex I by N-methylisoquinolinium ion and N-methyl-1,2,3,4-tetrahydroisoquinoline in isolated mitochondria prepared from mouse brain. 1,2,3,4-Tetrahydroisoquinoline (TIQ), which is structurally similar to MPTP, has been found in human brain and has been reported to inhibit the mitochondrial respiration as does 1-methyl-4-phenylpyridinium ion (MPP+). However, the potency of inhibition by TIQ is less than that of MPP+. In this study, we report the effects of N-methyl-1,2,3,4-tetrahydroisoquinoline (N-Me-TIQ) and N-methylisoquinolinium ion (N-Me-IQ+) on the mitochondrial electron transport system using mitochondria prepared from mouse brains. Five mM N-Me-TIQ and 500 microM N-Me-IQ+ inhibited complex I activity to 54% and 63% of the control, respectively. The IC50 of N-Me-TIQ and N-Me-IQ+ were approximately 6.5 mM and 650 microM, respectively. Neither substance inhibited complex II, III and IV activities. Kinetic analyses of N-Me-IQ+ on complex I activity revealed uncompetitive inhibition against NADH and non-competitive inhibition against ubiquinone. These inhibitory characteristics were the same to those of MPP+ and the inhibitory potency of N-Me-IQ+ on complex I activity was stronger than that of MPP+.


The cardiovascular effects of alpha-receptor blocking agents. To characterize selective alpha 1-adrenergic blockers as antihypertensive agents, particularly doxazosin. CHARACTERISTICS OF ALPHA-BLOCKERS: These agents lower elevated blood pressure by reducing peripheral arterial resistance without increasing the heart rate or reducing cardiac output. They also reduce left ventricular hypertrophy; improve an atherogenic lipid profile; reduce the risk of thrombotic complications; reduce the formation of fatty streaks, the precursor of advanced athersclerosis; have no adverse metabolic effects in diabetic hypertensives; have a comparable side-effect profile to that of other antihypertensive drugs; and are cost-effective. In addition to reducing high blood pressure, the alpha-blockers reduce a number of other cardiovascular risk factors. In attempts to solve the hypertension-coronary dilemma, these additional effects may prove to be of crucial importance.


The case for beta-blockers as first-line antihypertensive therapy. REASON FOR TREATMENT: In patients with asymptomatic high blood pressure, antihypertensive treatment is initiated for only one reason, to prevent the hypertensive sequelae of myocardial infarction, stroke and heart failure. MORBIDITY, MORTALITY AND SURROGATE ENDPOINTS: Only diuretics and beta-blockers have been shown to benefit hypertensive patients in terms of the hard endpoints morbidity and mortality. beta-Blockers and diuretics are cheaper than newer drugs and thus represent good value for money. It is not acceptable to use drug effects on plasma lipids or insulin resistance as measures of the effects on coronary heart disease, since dihydropyridine calcium antagonists improve these parameters while significantly increasing coronary heart disease events in the acute and chronic ischaemic situation. PATIENT PROFILING: Diuretics. Diuretics appear particularly suited to elderly hypertensives, especially those with isolated systolic hypertension, but they may increase cardiac events in younger and middle-aged diabetic and non-diabetic hypertensives. Angiotensin converting enzyme (ACE) inhibitors. ACE inhibitors are undoubtedly valuable in the presence of left ventricular dysfunction, and possibly in the diabetic in maintaining good renal function. beta-Blockers. beta-Blockers are particularly well suited to younger and middle-aged hypertensives at all blood pressure levels, especially white males; where ischaemia and/or stress is a factor, beta-blockers can significantly reduce the incidence of myocardial infarction and strokes. beta-Blockers benefit elderly hypertensives by preventing strokes and may prevent coronary heart disease if prescribed with a diuretic.


Thiazide diuretics: first-line therapy for hypertension. To compare low-dose thiazides to beta-blockers, angiotensin converting enzyme (ACE) inhibitors, calcium antagonists and alpha-blockers for simplicity, tolerability, efficacy, safety and cost-effectiveness as first-line treatment for hypertension. Review of short-term comparative studies, and the outcome of long-term trials with vascular complications of hypertension as endpoints. SIMPLICITY: Among the advantages of thiazides are a flat dose-response; no dose titration; effectiveness when used once a day; no first-dose hypotension; and few contra-indications. Thiazides are the best tolerated agents in patients over the age of 60 years and in younger women. They sometimes cause gout and impotence in younger men, in whom beta-blockers are equally acceptable first-line therapy. Thiazide-based regimens have consistently reduced vascular complications of hypertension, the real measure of efficacy. There is little evidence that regimens based on other drugs are effective in this sense. Concerns that thiazide-induced biochemical changes cause coronary events are baseless. An overview of outcome trials shows that thiazide-based treatment reduces coronary events significantly, and the reduction is not significantly different from that predicted by epidemiological data. Thiazide-based therapy has also reduced coronary events significantly and substantially in elderly patients with isolated systolic hypertension. Low-dose thiazide treatment needs minimal monitoring, and has proved most cost-effective in formal analyses. Low-dose thiazide treatment is a clear first-line choice for patients aged over 60 years and younger women, except those with diabetes or gout. In younger men there is little to choose between thiazides and beta-blockers.


[Immunohistochemical study of the human olfactory system]. Taurine (2-aminoethane sulfonic acid) and carnosine (beta-alanyl-L-histidine) are found in large quantities in the olfactory epithelium and bulb. Taurine is a structurally simple amino acid, and has been reported to have several putative roles, such as neurotransmitter, neuromodulator, neurogrowth factor and to function in membrane stabilization. Carnosine, on the other hand, has been suggested as a putative neurotransmitter in the olfactory system. We have succeeded in visualizing taurine- and carnosine-like immunoreactivities (LI) in the human olfactory mucosa, and also carnosine-LI in the human olfactory bulb. For this investigation, we collected specimens of the human olfactory bulb by autopsy and from the olfactory mucosa by biopsy, and compared localization of taurine- and carnosine-LI in several cases. By means of biopsy using Nakano's forceps, samples of olfactory mucosa were obtained from 5 cases: a 17 year old female, 23 year old male, 46 year old male, 47 year old male, and a 57 year old male. The olfactory bulb of a 1 month old male was collected at autopsy. These specimens were processed for immunohistochemical study according to the peroxidase-antiperoxidase (PAP) method. In the olfactory epithelium, taurine-LI was demonstrated in some primary olfactory neurons, and in basal cells. Carnosine-LI was observed only in primary olfactory neurons, i.e., dendrites, vesicles and axonal bundles of olfactory receptor cells, but not in basal cells. In the olfactory bulb, the olfactory nerve layer and the glomerular layer showed carnosine-LI positive reactions. Therefore, taurine and carnosine may possibly coexist in some olfactory neurons. Olfactory receptor cells are classified as sensory neurons.(ABSTRACT TRUNCATED AT 250 WORDS)


Dermatopathological aspects of restrictive dermopathy. We present an immunopathological and electronmicroscopic study of the skin of two newborns affected by restrictive dermopathy. Evidence of abnormal maturation was found in the epidermis, cutaneous appendages, dermis, and hypodermis. Our observations confirm two previous descriptions. We emphasize some unreported data concerning the L1 antigen and Factor XIIIa in the skin. The L1 antigen is expressed in the interadnexal epidermis, but not in hair follicles. This is the reverse pattern compared with normal skin. Factor XIIIa is poorly expressed in dermal dendrocytes, which appear rare compared with controls. The multiple defects in maturation found in all cutaneous tissues suggest a qualitative or quantitative aberration in control mechanisms of tissue interactions.


Chronic beta-blockade transregulates inhibitory A1 adenosine and muscarinic M2 receptors of the adenylyl cyclase system. Chronic beta-blockade has evolved to an important therapeutic strategy in medicine. Not all its therapeutic effects may be explained by its direct action on the beta-adrenergic system. We therefore investigated if chronic beta-blockade in vivo or in isolated cell systems may modulate also inhibitory receptors of the adenylyl cyclase system. Chronic treatment with metoprolol for 6 days (10 mg/day) induced an increase of beta-adrenergic receptors in rat cardiac plasma membranes (53 +/- 8 vs 80 +/- 12 fmol/mg protein). Simultaneously the density of cardiac muscarinic M2 receptors decreased significantly from 150 +/- 17 to 110 +/- 12 fmol/mg protein without any change of the affinity of the receptors for their agonists or antagonists. By this mechanism chronic beta-blockade leads to an unexpected impairment of the muscarinic-mediated inhibition of the adenylyl cyclase. This transregulation of inhibitory receptors by chronic beta-blockade was not restricted to the heart but also reduced the muscarinic receptors of rat lung (35 +/- 4 vs 24 +/- 3 fmol/mg protein). Additionally, other inhibitory receptors of the adenylyl cyclase system such as the A1 adenosine receptors of rat brain were reduced by chronic beta-blockade (532 +/- 32 vs 444 +/- 26 fmol/mg protein). This transregulation of A1 adenosine receptors occurred only after chronic beta-blockade with the active stereoisomer (-)-metoprolol whereas the (+)-isomer was ineffective. The ability of the remaining A1 adenosine receptors to form the agonist-promoted high affinity state was unaltered. Their reduction, however, was sufficient to abolish the phenylisopropyl-mediated inhibition of the adenylyl cyclase. To evaluate if this regulation of various inhibitory receptors in different organs may represent a general cellular regulation mechanism, we investigated whether this transregulation also occurred in isolated cells. Isolated smooth muscle cells derived from the vas deferens (DDT1 MF-2) were cultivated in the presence of the beta-blocker atenolol (10(-5) M) for 3 days. Chronic beta-blockade in these isolated cells induced an increase of beta-adrenergic receptors and concomitantly a significant decrease of A1 adenosine receptors (460 +/- 42 vs 368 +/- 18 fmol/mg protein). The affinity of the A1 adenosine receptors for their agonists and antagonists and the ability of the remaining receptors to form the agonist-promoted high affinity state remained unaltered. In contrast, the reduction of receptor density greatly impaired the adenosine-mediated inhibition of the adenylyl cyclase. These data demonstrate that chronic beta-blockade leads to a functionally significant reduction of inhibitory receptors of the adenylyl cyclase system.(ABSTRACT TRUNCATED AT 400 WORDS)


A case of simultaneous bilateral nonseminomatous testicular tumors in persistent müllerian duct syndrome. Persistent müllerian duct syndrome is characteristically associated with unilateral or bilateral cryptorchidism. Like other undescended testes, these gonads are at an increased risk of malignant transformation. We report a case of synchronous bilateral mixed germ cell tumors in the cryptorchid testes of a patient with the persistent müllerian duct syndrome.


Establishment and characterization of doxorubicin-resistant human bladder cancer cell line, KK47/ADM. A human bladder cancer cell line resistant to doxorubicin, KK47/ADM has been established in vitro by exposing KK47 parent cells to progressively higher concentrations of the drug over a period of 16 months. The KK47/ADM was 271 times more resistant to doxorubicin than the KK47 parent. The KK47/ADM exhibited cross-resistance to doxorubicin derivatives (pirarubicin, epirubicin), vinca alkaloids (vinblastine, vincristine) and etoposide, but not to cisplatin, carboplatin, mitomycin C, peplomycin and methotrexate. Unlike the KK47 parent, about 70% of the KK47/ADM cells showed a positive reaction with monoclonal antibody against P-glycoprotein, MRK16. Uptake and efflux studies with [14C]doxorubicin indicated that the resistance exhibited by the KK47/ADM line was mainly due to a lower accumulation of the drug caused by an increased active efflux, and these were reversed in the presence of verapamil. Although verapamil enhanced doxorubicin sensitivity of KK47/ADM, a complete overcoming of the resistance could not be obtained. These two lines with different chemosensitivity are thus considered to be a useful model for developing new chemotherapeutic strategies against multidrug resistant bladder cancer.


Nocturnal myoclonus observed in a patient with neuroleptic-induced akathisia. An all-night polysomnogram was twice recorded in a patient with neuroleptic-induced akathisia (NIA). The polysomnogram revealed nocturnal myoclonus. After disappearance of akathisia by the administration of clonazepam, we recorded the second polysomnogram. At the second examination, sleep efficacy increased and the total number of nocturnal myoclonus decreased remarkably. The mean inter-movement interval of nocturnal myoclonus prolonged. These findings suggest a close relationship between the mechanisms of neuroleptic-induced akathisia and nocturnal myoclonus.


A study of clinical response to different kinds of neuroleptics in first time medicated schizophrenics. Clinical responses to different kinds of neuroleptics in fresh schizophrenics were prospectively investigated. The scales used were the Global Assessment Scale (GAS), Brief Psychiatric Rating Scale (BPRS) and Psychiatric Evaluation Scale (PES). The 48 subjects were classified into three groups, 16 in the phenothiazine response group, 19 in the butyrophenone response group and 13 in the nonresponse group. For the schizophrenics who displayed negative symptoms such as motor retardation and blunted affect, while displaying milder positive symptoms, phenothiazine drugs were effective. Contrarily, for the schizophrenics who displayed severe positive symptoms such as hallucination and delusion while displaying milder negative symptoms, butyrophenone drugs were effective. Large dosages of the drug did not enhance the curative effect in most cases.


Convulsive seizures in schizophrenic patients induced by zotepine administration. One hundred twenty-nine schizophrenic inpatients who were administered zotepine were studied to see if they had zotepine-induced convulsive seizures. Twenty-two patients had grand mal seizures during the administration periods. The incidence of the seizure was 17.1% and was higher than that in previous reports. The average duration of zotepine administration before the seizure was 48.3 days. The incidence of the seizure was closely related to the daily dosage of zotepine, but there was no significant correlation between the daily dosage of zotepine and the duration of administration before the onset of the seizure. The patients who received a combined administration with the higher dose of zotepine and other phenothiazines were revealed to be more likely to have the seizure. In addition, young patients and patients with a past history of head injuries showed a high incidence of the seizure with the administration of zotepine.


Voluntary intake of alcohol is attenuated by ipsapirone in mice and role of 5-HT1A receptor. Emerging evidences have suggested that the brain serotonin (5-hydroxytryptamine, 5-HT) neurotransmitter system is involved in the compulsive alcohol-seeking behaviors in humans and animal models. The aim of this study is to examine the effect of ipsapirone, which is a specific 5-HT1A agonist with a pyrimidinylpiperazine structure, on alcohol consumption in mice (C57BL/6J) by a voluntary alcohol intake paradigm. When the consumed alcohol was expressed as g/kg B.W., the total 12-day amount was significantly lower in the ipsapirone-treated mice than in the saline-treated mice. However, 5-HT1A receptor binding sites labeled with [3H]8-OH-DPAT in hippocampal membranes did not differ significantly in either the total number of binding sites (Bmax) or dissociation constant (Kd) between the two groups. The possible mechanism regarding the role of ipsapirone that attenuated the alcohol consumption, and its relationship to the subtyping 5-HT receptors are further discussed.


A case of tardive Tourette-like syndrome. We have had experience in treating tardive Tourette-like syndrome on a chronic schizophrenic patient. The patient was a 38-year-old woman. A diagnosis of schizophrenia was made in 1971 and she received repeated medications for 17 years. In 1989, she began to show vocal tic with coprolalia and motor tic. The medications were haloperidol 18 mg, zotepine 200 mg, levomepromazine 100 mg, biperiden 3 mg and nitrazepam 10 mg at the beginning of Tourette-like syndrome. We have tried to change the medications but this tardive Tourette-like syndrome continued to hang on. However, the symptoms gradually improved after a change in drugs; cessation of biperiden 3 mg and the administration of clonazepam 3 mg. The present case suggested that tardive Tourette-like syndrome might be a subtype of neuroleptic-associated tardive syndromes which might be treated with clonazepam.


Regression in schizophrenia and its therapeutic value. Using the regression evaluation scale, 25 schizophrenic patients were classified into three groups of Dissolution/autism (DAUG), Dissolution----attachment (DATG) and Non-regression (NRG). The regression of DAUG was of the type in which autism occurred when destructiveness emerged, while the regression of DATG was of the type in which attachment occurred when destructiveness emerged. This suggests that the regressive phenomena are an actualized form of the approach complex. In order to determine the factors distinguishing these two groups, I investigated psychiatric symptoms, mother-child relationships, premorbid personalities and therapeutic interventions. I believe that these factors form a continuity in which they interrelatedly determine the regressive state. Foremost among them, I stressed the importance of the mother-child relationship.


Nephropathies and exposure to perchloroethylene in dry-cleaners. Even in specific risk groups, the relation between exposure to organic solvents and chronic renal diseases remains controversial. Thus, in a collaborative European study, we assessed the renal effects of occupational exposure to perchloroethylene (PCE) in dry-cleaners compared with matched controls who were simultaneously examined. Single high and low molecular weight proteins, kidney-derived antigens and enzymes, and prostanoids were measured in urine. beta 2-microglobulin, creatinine, laminin fragments, and anti-glomerular basement membrane antibodies were also measured in serum. A canonical function based on 23 such variables correctly classified 93% of individuals as either PCE-exposed or controls; with 13 markers, group membership was identified in 87% of subjects. Increased high molecular weight protein in urine was frequently (17/50 vs 1/50, p less than 0.0001) associated with tubular alterations. Changes were consistent with diffuse abnormalities along the nephron in workers exposed to low levels of PCE (median 15 parts per million). Generalised membrane disturbances might account for the increased release of laminin fragments, fibronectin, and glycosaminoglycans, for high molecular weight proteinuria, and for the increased shedding of epithelial membrane components from tubular cells with different location along the nephron (brush-border antigens and Tamm-Horsfall glycoprotein). These findings of early renal changes indicate that solvent-exposed subjects, especially dry-cleaners, need to be monitored for the possible development of chronic renal diseases.


Reciprocal alterations of GMP reductase and IMP dehydrogenase activities during differentiation in HL-60 leukemia cells. The study was undertaken to elucidate the regulatory roles of GMP reductase (GMPR) and IMP dehydrogenase (IMPDH) on purine interconversion during differentiation. Treatment of HL-60 cells with retinoic acid (1 microM) induced granulocytic differentiation which was accompanied with a 2.4-fold increase in GMPR and 55% decrease in IMPDH activities. Maturation induced by 12-O-tetradecanoylphorbol 13-acetate or dimethylsulfoxide was also associated with similar reciprocal alterations. Incubation with guanosine (200 microM), which expands the guanine nucleotide pool, elevated GMPR (1.9-fold) and decreased IMPDH (73%) activities. The synchronous and opposing alterations in GMPR and IMPDH activities should amplify the metabolic response due to differentiation or guanylate pool expansion.


Randomised trial of cardiotocography alone or with ST waveform analysis for intrapartum monitoring. It is possible to record the fetal electrocardiographic waveform (ECG) from the scalp electrode used in labour for detection of fetal heart rate. Animal and observational studies of changes in the ST waveform of the ECG during hypoxia suggest that a combination of heart rate and ST waveform analysis might improve the predictive value of intrapartum monitoring. In a randomised trial, we have studied intervention rates and neonatal outcome for high-risk labours monitored either by conventional cardiotocography (CTG) or by ST waveform analysis plus CTG. 1200 women with pregnancy of at least 34 weeks' gestation were assigned to the groups when the decision to apply a fetal scalp electrode was made. Neonatal outcome was assessed by umbilical-cord blood gas analysis, Apgar scores, resuscitation needed, and postnatal course. All recordings were retrospectively viewed by an observer unaware of clinical details to check adherence to the trial protocol. The addition of ST waveform monitoring to CTG substantially reduced the proportion of deliveries for fetal distress (ST + CTG 27/615 vs CTG 58/606; p less than 0.001). The groups did not differ in rate of operative delivery for other reasons, incidence of asphyxia at birth, or neonatal outcome. Metabolic acidosis and low 5 min Apgar scores were less common in the ST + CTG than the CTG group, but not significantly so. The only case of birth asphyxia in the ST + CTG group was identified by both heart rate and ST changes. The review of recordings showed that the reduction in intervention rate was among cases with CTG patterns classified as normal or intermediate, whereas there was no difference in intervention rates among cases with abnormal recordings. Our findings confirm that ST waveform analysis discriminates CTG changes in labour and that our protocol for interpretation is safe. Further randomised studies are warranted.


Induction of CD13 expression on fresh myeloid leukaemia: correlation of CD13 expression with aminopeptidase-N activity. CD13 has proved to be a useful cell surface marker for depicting haematopoietic cells of the myeloid and monocytic lineages. Sequence data has shown CD13 to bear strong homology to Aminopeptidase-N. Expression of this antigen on myeloid leukaemic cells is, however, variable. We have looked at the effects of a phorbol ester PMA and a haematopoietic growth factor GM-CSF on the expression of CD13 displayed by a selected group of myeloid leukaemias at presentation and by normal peripheral blood granulocytes. We have found that PMA but not GM-CSF was able to stimulate CD13 expression on fresh myeloid leukaemic cells but granulocytes were stimulated by either PMA or GM-CSF. In addition, we have correlated CD13 expression with Aminopeptidase-N enzyme activity on fresh myeloid leukaemic cells. These results suggest that CD13 is functionally active on leukaemic cells and normal granulocytes.


Molecular analysis of an ataxia telangiectasia T-cell clone with a chromosomal translocation t(14;18)--evidence for a breakpoint in the T-cell receptor delta-chain gene. We established a clonal T-cell line with a reciprocal chromosomal translocation t(14;18)(q11;q23) from a patient with ataxia telangiectasia (AT) and T-cell chronic lymphocytic leukemia (T-CLL). The tumor cells and the derived T-cell line were compared with respect to phenotype, karyotype, and rearrangement pattern. Restriction fragment analyses of the T-cell receptor (TCR)-delta gene, which is located within the TCR-alpha gene on chromosome 14q11, indicated that the breakpoint is located within the TCR-delta locus, splitting the TCR-delta gene between the variable and joining segments. This specific chromosomal translocation was only detected in the derived T-cell line and may be involved in the genesis of T-cell malignancies in AT.


Clozapine, single photon emission tomography, and the D2 dopamine receptor blockade hypothesis of schizophrenia. According to the dopamine hypothesis of schizophrenia, D2 receptor blockade is essential for a drug to have antipsychotic potency, and antipsychotic potency and D2 blockade are linearly related in vitro. To test this assumption in vivo, we have compared clinical response with central D2 dopamine receptor availability measured by 123I-iodobenzamide single photon emission tomography in two groups of schizophrenic patients. 6 patients were on typical antipsychotic drugs and 10 were on the atypical antipsychotic clozapine, including 2 patients from the first group. The patients on typical antipsychotics showed poor therapeutic response despite D2 receptor blockade. Significant clinical improvement occurred in all patients on clozapine, but at a lower level of D2 blockade by the drug. These findings suggest a more complex relation between D2 blockade and clinical efficacy than was previously thought.


Improved diagnosis of Pneumocystis carinii infection by polymerase chain reaction on induced sputum and blood. Detection of Pneumocystis carinii by the polymerase chain reaction (PCR) may facilitate non-invasive diagnosis of P carinii pneumonia and study of its epidemiology. We have compared the sensitivity and specificity of two PCR methods with those of conventional staining for detection of P carinii in induced sputum, bronchoalveolar lavage fluid (BAL), and blood. Of 71 sputum samples, 17 were from patients with microbiologically confirmed P carinii pneumonia. A nested PCR method correctly identified the presence of P carinii in all 17 (100% sensitive, 95% confidence interval [CI] 81-100%) and found no organisms in 50 of 54 microbiologically negative samples (93% specific, 95% CI 82-98%). PCR with a single primer pair was 71% sensitive (44-90%) and 94% specific (85-99%). The sensitivity of conventional staining methods (direct and indirect fluorescence antibody and toluidine-blue-O tests) was significantly less (38-53%) than that of nested PCR (p less than 0.05). In BAL, neither PCR method was significantly better than the conventional staining methods. P carinii was detected in BAL or sputum from 10 immunocompromised patients without microbiological evidence of P carinii pneumonia, which suggests that symptom-free carriers or subclinical infection can exist. P carinii was detected by nested PCR in blood from 2 of 3 patients with disseminated pneumocystosis but in only 1 of 11 patients with P carinii infection restricted to the lungs. Nested PCR on induced sputum is more sensitive than conventional staining methods for the diagnosis of P carinii pneumonia and provides a non-invasive method of detecting disseminated disease.


Effect of stereotactic thalamic lesion on essential tremor. The cause of essential (low-frequency) tremor is unknown and its relation to physiological (high-frequency) tremor is unclear. We assessed essential tremor in one patient before and after a stereotactic thalamic lesion. The procedure changed the size of the tremor in the right hand but not in the left. Persistence of a low-frequency component suggested that essential tremor was an additional feature superimposed on physiological tremor in this patient. The focus of essential tremor seems to be an autonomous central generator that is independent of physiological tremor mechanisms.


CD8 lymphocytosis and pseudotumoral splenomegaly in HIV infection. Three patients infected with human immunodeficiency virus (HIV) presented with pseudotumoral splenomegaly, CD8 lymphocytosis (3.5-5.1 x 10(9)/l), and hypergammaglobulinaemia. Spleen and bone marrow showed diffuse CD8 lymphocyte and plasma-cell infiltration. Amplification of the T-cell-receptor gamma chain gene did not reveal any clonal T-cell population. Phenotypic analysis showed a predominance of CD8/CD57 suppressor T cells with expression of activation markers (DR and CD38). No cytotoxic T lymphocytes specific for HIV could be detected. The three patients shared the HLA haplotype A1, B8, DR3. The association with this haplotype suggests a genetically determined host immune response to HIV.


Prenatal screening for cystic fibrosis.

Prenatal screening for cystic fibrosis. Screening for carriers of CF (cystic fibrosis) is now possible but the best way of delivering such a service is unknown. In one model 4348 women attending antenatal clinics in an Edinburgh maternity hospital were invited to participate in a trial of prenatal screening. Mouthwash samples were tested for six CF alleles (85% of mutant genes) and when a woman was found to be a CF carrier her partner was also tested. Heterozygous couples were offered prenatal diagnosis. 609 (14%) women declined to enter the trial and another 574 (13%) were not screened, usually because of late booking. Among the remaining 3165 women there were 111 carriers of a CF gene (1 in 29). 4 of these 111 had carrier partners and these couples opted for prenatal diagnosis, the 1 pregnancy with an affected fetus being terminated. The psychological impact of screening was assessed by the general health questionnaire. There was a significant increase in stress at the time of the test result among women identified as carriers. However, this disappeared when their male partners tested normal and did not reappear later in the pregnancy. By providing time for couples to discuss the possibility of screening and by offering the test at a point (the antenatal booking clinic) at which most pregnant women are seen, this approach has advantages, provided that counselling is readily available.


Psychological and social consequences of community carrier screening programme for cystic fibrosis. We have assessed the effect of screening for cystic fibrosis (CF) carrier status on anxiety levels, attitudes, knowledge and actions of participants in a pilot programme conducted through primary health care services. Over 3000 individuals were screened and 100 carriers with no previous family history were identified. Varying degrees of anxiety were found to be associated initially with a positive result, but most of this was allayed by genetic counselling, and we find no adverse long-term psychological consequences in carriers. Most discussed carrier status with their partner (89%), parents, other relatives and also with friends; 87% of partners to whom testing was suggested have been screened. Those testing positive indicated that knowledge of carrier status would be considered in future reproductive decisions, and after 6 months carriers retained a reasonable level of knowledge about CF and its inheritance. Carriers and non-carriers uniformly approve of screening and are glad to have been tested. Knowledge of CF in the sample of non-carriers has also increased after testing, suggesting screening may improve understanding of CF among the entire target population. Fears of possible social costs of screening may be ill-founded.


Healing rituals and sacred serpents.

Healing rituals and sacred serpents. Votive tablets found during the excavation of shrines of the Graeco-Roman god of medicine (Asklepios or Aesculapius) associate the healing of superficial lesions with contact with the oral cavity of non-poisonous serpents. We suggest that this may have been the empirical exploitation of the healing properties of salivary growth factors. By immunohistochemistry and immunoblotting we demonstrate the expression of the epidermal growth factor and its receptor in the oral, upper digestive, and salivary epithelia of Elaphe quatuorlineata, a species probably used in healing rituals.


Modulation of multidrug-resistant multiple myeloma by cyclosporin. The Leukaemia Group of the EORTC and the HOVON. Resistance to chemotherapy in refractory multiple myeloma is frequently associated with expression of multidrug resistance (MDR). In resistant cells, intracellular accumulation of doxorubicin and vincristine does not occur because the MDR-1 gene product, a membrane glycoprotein (PgP), is an energy-dependent efflux pump. Cyclosporin is one of several non-cytotoxic drugs that can block the function of PgP. In a prospective study, we assessed the possibility that cyclosporin could be used clinically to modulate MDR. We studied 21 patients with multiple myeloma; disease had progressed during primary chemotherapy in 6 and was resistant to VAD (vincristine, doxorubicin, dexamethasone) in 15. The patients received cyclosporin by continuous infusion during VAD treatment; there were three cyclosporin dosage groups (5, 7.5, 10 mg/kg daily). Serum cyclosporin concentrations adequate for MDR modulation were reached in all patients receiving 7.5 or 10 mg/kg daily. 47% (7) of the VAD-refractory patients and 48% (10) of the whole group responded to VAD. Before treatment, MDR-1 expression was present in 12 patients. After VAD plus cyclosporin, no MDR-1-positive plasma cells were present in 6 of 8 patients tested. The response rate in MDR-1-positive patients was 58% compared with 33% in all our patients. Toxic effects were mild and reversible and did not include nephrotoxic or serious cardiovascular side-effects. 12 months after the start of treatment, survival was 85%, and disease-free survival at a median of 9 months after the response was 65%. Thus, in multiple myeloma clinical resistance to VAD can be circumvented by cyclosporin, which enables the cytotoxic drugs to eliminate resistant myeloma cells.


Abnormal expression of wild type p53 protein in normal cells of a cancer family patient. Mutations in the p53 gene are the commonest specific genetic change in human cancer. In normal tissues, p53 protein is present in such low quantities that it is not readily detectable by immunochemical techniques. However, in many tumour cells large amounts of p53 protein accumulate and can be seen by simple immunohistochemical staining; this is generally attributed to the accumulation of stabilised, mutant protein. We have found a mother and daughter, who both have a history of breast cancer, who show strong immunohistochemical staining of p53 in most of their normal epithelial and mesenchymal cells. Their family has a history of multiple cancers developing at an early age. Detailed protein analysis and gene sequencing of material obtained from cultured cells, grown from a skin biopsy taken from the daughter, suggest that her cells contained large quantities of normal (unmutated) p53. We suggest that this phenotype defines a new inherited cancer susceptibility syndrome that is distinct from the germ-line mutations in p53 found in some Li-Fraumeni families. This new syndrome affects p53 tumour suppressor function through an indirect mechanism that stabilises normal p53. It remains to be established whether this mechanism also contributes to the accumulation of p53 in sporadic cancers.


Growth hormone response to clonidine in central and peripheral primary autonomic failure. Patients with primary autonomic failure may have either pure autonomic failure (PAF) or multiple system atrophy (MSA) in which there is additional neurological involvement. Distinction between PAF and MSA at an early stage is important because a wide range of complications is associated with MSA, which has a poor response to drug therapy and a less favourable prognosis. We have investigated the growth hormone (GH) releasing effects of clonidine in patients with PAF and MSA to see whether this hormonal response could serve as a neuroendocrine marker to distinguish between the groups. Age-matched normal subjects were studied as controls. Both groups of patients had severe postural hypotension due to primary sympathetic failure of presumed central origin in MSA and peripheral origin in PAF. After clonidine, plasma GH concentrations increased in controls and PAF, with no change in MSA. Changes in plasma glucose and insulin concentrations were similar in all groups. Clonidine, therefore, stimulates growth hormone release in PAF but not MSA and may serve as a neuroendocrine marker in differentiating patients with MSA and a central autonomic defect from those with PAF with a peripheral defect.


Vitamin A supplementation and child survival. Previous studies of the effect of 6-monthly vitamin A supplementation on child mortality have given conflicting results. In other trials, more frequent doses of vitamin A have significantly reduced mortality among children at risk of vitamin A deficiency. We have done a double-blind, placebo-controlled trial of vitamin A supplementation in the Sudan among 28,753 children aged 9-72 months at risk of vitamin A deficiency. Children were assigned to receive either 200,000 IU vitamin A and 40 IU vitamin E every 6 months (vitamin A group) or 40 IU vitamin E alone (placebo group). During the 18 months of follow-up, there were 120 deaths (8.4/1000) in the vitamin A group and 112 (7.9/1000) in the placebo group (relative risk 1.06, 95% confidence interval 0.82-1.37). Controlling for geographic site, round of observation, anthropometry, morbidity, dietary intake of vitamin A, sex, and all baseline differences between the two groups did not change the results. Children living in poor and unsanitary environments, younger children, and those sick, stunted, wasted, or consuming diets low in vitamin A were at a significantly higher risk of dying. The lack of an effect of large-dose vitamin A supplementation on mortality, despite a clear association between dietary vitamin A and mortality, underscores the need to identify factors that modify the efficacy of vitamin A supplements as a public-health measure. Reducing poverty, improvements in sanitation, and access to adequate diets should remain the main goals to improve child survival.


Simian immunodeficiency virus needlestick accident in a laboratory worker. The macaque monkey infected with simian immunodeficiency virus (SIV) is an animal model of the acquired immunodeficiency syndrome. We investigated a laboratory worker who was exposed by needlestick accident to blood from an SIV-infected macaque. Seroreactivity to SIV developed within 3 months of exposure, with antibody titres peaking from the third to the fifth month and declining thereafter. Polymerase chain reaction for SIV sequences and cultures of peripheral-blood mononuclear cells failed to show infection. Inoculation of an SIV-negative monkey with blood from the worker did not cause infection. Animal-care and laboratory workers should adhere strictly to recommended procedures to avoid accidental exposures when working with SIV-infected animals or specimens.


Acquired immunodeficiency without evidence of infection with human immunodeficiency virus types 1 and 2. There have been three published cases of acquired immunodeficiency in which no evidence for infection with human immunodeficiency virus (HIV) types 1 and 2 was found. We have identified five other individuals, from the New York City area (four who have known risk factors for HIV infection), with profound CD4 depletion and clinical syndromes consistent with definitions of the acquired immunodeficiency syndrome (AIDS) or AIDS-related complex. None had evidence of HIV-1, 2 infection, as judged by multiple serologies over several years, standard viral co-cultures for HIV p24 Gag antigen, and proviral DNA amplification by polymerase chain reaction.


Seasonal cryptogenic organising pneumonia with biochemical cholestasis: a new clinical entity. The term cryptogenic organising pneumonia has been used for the combination of dyspnoea, cough, pleuritic pain, widespread shadows on chest radiographs, and histological evidence of intra-alveolar organisation with buds of granulation tissue within the alveoli. We report 12 patients with seasonal recurrence of this disorder for between 3 and 11 years. In all 12 patients, symptoms recurred between late February and early May every year, tending to increase in severity each year, and resolved between June and January. Chest radiography and computed tomography showed bilateral consolidation. Lung biopsy samples showed intra-alveolar buds of granulation tissue. There were many neutrophils within the lumina of medium-sized airways and terminal bronchioles showed evidence of obstruction by granulation tissue. Functionally, the predominant defect was restrictive and only 2 patients (life-long non-smokers) had airflow limitation. All 12 patients had very high activities of liver enzymes, suggesting intrahepatic cholestasis, but no other evidence of liver disease. Cultures of blood, sputum, lung tissue, and bronchoalveolar lavage fluid, viral screening, and complement fixation tests were consistently negative. In all patients all abnormalities responded rapidly to oral steroid therapy. These findings suggest a seasonal syndrome of organising pneumonia and biochemical abnormalities indicative of intrahepatic cholestasis. No aetiological factor has been identified, but the nature and periodicity of the illness point to an inhaled agent present in the environment for a limited period every year.


Treatment of small hepatocellular carcinomas. There is growing interest in screening to detect symptomless hepatocellular carcinoma (HCC), which should be easier to treat than symptomatic tumours. Combined alpha-fetoprotein and ultrasound monitoring can detect HCCs of 1 cm, and Lipiodol retention can be detected in tumours smaller than 1 cm. A number of treatment options are available. Surgical resection may be curative in selected patients with a single small tumour, but the cirrhotic patient is left with a diseased liver and the risk of tumour recurrence or death from underlying liver dysfunction. Orthotopic liver transplantation is a rational treatment for patients with decompensating cirrhosis and a small HCC, but it is expensive and necessitates immunosuppression. A variety of targeted or local therapies, either individually or in combination, can be used to treat HCC. These include percutaneous alcohol injection into an HCC, which may be an alternative to surgical resection. Tumour necrosis can be seen after targeted Lipiodol chemotherapy or radiotherapy. Transcatheter arterial embolisation selectively embolises the feeding artery, and can be combined with Lipiodol chemotherapy. Small tumours are thus amenable to treatment, even in patients who cannot have surgery. Screening and treatment for symptomless HCC seems justified, unless controlled trials teach us differently.


Supersensitivity of sigma receptors after repeated administration of cocaine. We investigated the role of sigma receptors in the expression of behavioral sensitization induced by cocaine. Rats received intraperitoneal injections of either 20 mg/kg cocaine or saline once daily for 14 consecutive days. Cocaine-treated rats became sensitized. After a 5-day abstinence period, a challenge dose of (+)-3-[3-hydroxyphenyl]-N-(1-propyl)piperidine ((+)-3-PPP), a sigma receptor agonist, was administered. (+)-3-PPP at doses of 12 and 24 mg/kg induced significantly more frequent rearing and more potent stereotypy consisting of repetitive head movement and sniffing in cocaine-sensitized rats than in saline-pretreated rats. These enhanced responses to (+)-3-PPP lasted for at least a month. The enhanced responses to (+)-3-PPP were attenuated by 30 mg/kg BMY 14802, a putative sigma antagonist, and also attenuated by 100 mg/kg (+/-)-sulpiride, a D2 dopamine antagonist. These findings show that repeated administration of cocaine produces lasting supersensitivity of simga receptors, which may induce subsequent activation of dopaminergic transmission.


Unexplained CD4+ T-lymphocyte depletion in persons without evident HIV infection--United States. Since 1989, 21 persons with unexplained CD4+ T-lymphocyte depletion, but without evident human immunodeficiency virus (HIV) infection, have been described (1-12). These reports included persons who have resided in the United States and six other countries and who sought medical care for conditions often associated with immune deficiency. Some of these cases were also described at the VII International Conference on AIDS/III STD World Congress in Amsterdam. In addition, CDC has received reports of five persons from three states who have had persistently low CD4+ T-cell levels but who have had no evidence of HIV infection or underlying disease processes or therapies known to be associated with T-cell depletion. In some of these five patients, opportunistic infections were diagnosed that frequently occur in persons with acquired immunodeficiency syndrome (AIDS). This report describes preliminary clinical and laboratory findings from an ongoing investigation by CDC of these five patients.


Pharmacological characteristics of alpha 2-adrenergic receptors: comparison of pharmacologically defined subtypes with subtypes identified by molecular cloning. On the basis of extensive radioligand data and more limited functional data, three pharmacological subtypes of alpha 2-adrenergic receptors have been identified. More recently, three human genes or cDNAs for alpha 2-adrenergic receptors have been identified by molecular cloning. The relationship, however, among the pharmacologically defined subtypes and those identified by molecular cloning has not been clear. In order to resolve this issue, we have compared the pharmacological characteristics of the receptors identified by molecular cloning and expressed in COS-7 cells with the characteristics of the pharmacologically defined receptors in their respective prototypic tissue or cell line. The affinities (Ki values) of 12 subtype-selective alpha 2-adrenergic antagonists were determined for the alpha 2 receptor in the six preparations, by radioligand binding. Correlation analyses of the pKi values indicate that the alpha 2A subtype, as defined in the HT29 cell line, the alpha 2B receptor of the neonatal rat lung, and the alpha 2C subtype, as defined in an oppossum kidney cell line, correspond to the cloned human alpha 2-C10, alpha 2-C2, and alpha 2-C4 receptor subtypes, respectively.


Up-regulation of N-methyl-D-aspartate receptors on cultured cortical neurons after exposure to antagonists. The density of N-methyl-D-aspartate (NMDA) receptors on membranes prepared from cultured cortical neurons was determined using binding assays with [125I]I-MK-801 after exposure of cultures to antagonists of the NMDA receptor complex. The density of binding sites for [125I]I-MK-801 was increased by 40-80% after exposure to D-2-amino-5-phosphonopentanoic acid (D-AP5), with no change in the number or viability of neurons. The effect of D-AP5 was concentration dependent, with an EC50 of 10 microM. Up-regulation of NMDA receptors was observed after 2-7 days but not after 1 day of exposure to 100 microM D-AP5. The density of NMDA receptors was also increased after exposure of cells to CGS 19755 and MK-801 but not after exposure to the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)/kainate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione. The binding of [3H]AMPA was unaltered after exposure to D-AP5. These results demonstrate that the density of NMDA receptors on cultured neurons can be selectively up-regulated by exposure to NMDA receptor antagonists. Increases in the density of NMDA receptors occurring in vivo could complicate therapeutic approaches to the treatment of neurological disorders.


Cloning of two mouse genes encoding alpha 2-adrenergic receptor subtypes and identification of a single amino acid in the mouse alpha 2-C10 homolog responsible for an interspecies variation in antagonist binding. Molecular cloning and ligand binding studies have shown the alpha 2 class of adrenergic receptor (alpha 2-AR) to be a family of at least three related subtypes in humans. These studies have not, however, identified distinct subtype-specific functions for these receptors in vivo. It should be possible to extend the analysis of alpha 2-AR subtype function to the animal level through the use of experimental mammalian embryology in mice. To begin this process, we have isolated two mouse genomic clones encoding alpha 2-AR subtypes and expressed these genes in COS-7 cells for binding studies. Sequence homology and ligand binding data allow the assignment of one clone (M alpha 2-4H) as the mouse homolog of the human alpha 2-C4 subtype. The other clone (M alpha 2-10H) closely resembles the human alpha 2-C10 subtype in sequence but binds with significantly lower affinity to yohimbine and rauwolscine, members of a distinct class of bulky alpha 2-selective antagonists commonly used to evaluate alpha 2-AR function in vivo. To define the domain(s) responsible for this unusual binding property, we constructed a series of M alpha 2-10H/human alpha 2-C10 chimeric receptors. Analysis of these receptors identified a conservative Cys201 to Ser201 change in the fifth transmembrane domain of M alpha 2-10H as being responsible for the low affinity of the mouse receptor for yohimbine.


Pharmacological properties of two cloned somatostatin receptors. Previous studies have shown that at least two subtypes of somatostatin (SRIF) receptors (SRIF1 and SRIF2) are expressed in mammalian cells. SRIF1 receptors have high affinity for MK 678, whereas SRIF2 receptors have no affinity for MK 678 but selectively bind peptides with structures similar to that of CGP 23996. Recently, two SRIF receptor genes have been cloned from human and mouse genomic libraries. In the present study, the pharmacological properties of these two cloned SRIF receptors, expressed in Chinese hamster ovary (CHO) cells, were investigated, to determine whether they have any similarity to the previously described SRIF1 and SRIF2 receptor subtypes. Both cloned receptors could be labeled with 125I-Tyr11-SRIF and exhibited high affinity for SRIF. The SSTR1 receptor could also bind CGP 23996-like compounds but not MK 678. In contrast, the SSTR2 receptor was insensitive to CGP 23996-like compounds but bound MK 678 with high affinity. These findings indicate that the peptide specificities of the cloned SSTR1 and SSTR2 receptors differ from each other. Pretreatment of CHO cells expressing the two cloned SRIF receptors with SRIF abolished high affinity agonist binding to the cloned SSTR2 receptor but not the cloned SSTR1 receptor. Agonist binding to SSTR1 receptors was not significantly affected by guanosine-5'-)-(3-thiotriphosphate) or pertussis toxin pretreatment, whereas agonist binding to SSTR2 receptors was inhibited by both treatments. These findings suggest that SSTR2 receptors can be regulated and they associate with pertussis toxin-sensitive guanine nucleotide-binding proteins, whereas SSTR1 receptors do not. SRIF is a potent inhibitor of adenylyl cyclase activity in mammalian cells. However, neither the cloned SSTR2 nor SSTR1 receptor mediated SRIF inhibition of adenylyl cyclase activity in stably transformed CHO cells or COS-1 cells transiently expressing the cloned receptors, suggesting that neither cloned receptor couples to adenylyl cyclase. The results of these studies indicate that the two cloned SRIF receptors have different pharmacological properties. The characteristics of the cloned SSTR2 receptor are similar to those of the previously described SRIF1 receptor, and the characteristics of the cloned SSTR1 receptor are similar to those of the previously described SRIF2 receptor.


Expression of c-fos in human and murine multidrug-resistant cells. In both mouse sarcoma 180 and human KB cells selected for the multiple drug resistance (MDR) phenotype, there is an elevation in the steady state mRNA level of c-fos. There is no detectable gene amplification for c-fos, nor is there any significant change in the rate of mRNA transcription or degradation, suggesting that other factors are responsible for the increased expression level in resistance. Cells selected for resistance to methotrexate, a drug not in the MDR group, do not have an increase in c-fos mRNA expression. When drug-sensitive cells are exposed for 30 min to an ED50 concentration of vinblastine, Adriamycin, colchicine, or VP-16, but not to methotrexate or cisplatin, there is a 3-6-fold induction in the level of c-fos message. Because the former drugs are members of the MDR class and the latter are not, the results are consistent with the hypothesis that induction of c-fos by low levels of cytotoxic drugs may be an early event in the acquisition of the MDR phenotype. If this were the case, then c-fos would be expected to act in concert with c-jun to control transcription by binding to a specific DNA regulatory site. Consistent with this explanation is the existence of an AP-1 sequence in the promotor region for the P-glycoprotein gene (mdr1), as well as the fact that c-jun is also overexpressed in MDR cells.


Persistent paralysis in critically ill patients after long-term administration of vecuronium. The muscle relaxant vecuronium is sometimes administered to facilitate mechanical ventilation. Neuromuscular paralysis lasting up to seven days may occur after the termination of long-term administration (i.e., more than two days) of vecuronium in critically ill patients. We investigated the role of clinical factors and plasma concentrations of vecuronium and its metabolite in causing this prolonged neuromuscular blockade. We studied 16 critically ill adult patients (8 women and 8 men) who had received vecuronium to facilitate mechanical ventilation for at least two consecutive days. Clinical factors and plasma concentrations of vecuronium and 3-desacetylvecuronium, the active metabolite of vecuronium, were compared in patients with and without prolonged neuromuscular blockade. In addition, we performed detailed pharmacokinetic studies in the patients without prolonged neuromuscular blockade. Seven of the 16 patients had prolonged neuromuscular blockade, lasting from six hours to more than seven days, after the termination of vecuronium therapy. These seven patients, six of whom were women, had higher plasma magnesium concentrations and lower arterial blood pH values than the nine patients without prolonged neuromuscular blockade. They also had higher plasma concentrations of 3-desacetylvecuronium and a higher frequency of renal failure (seven of seven patients vs. four of nine patients, P less than 0.03). In the patients without prolonged neuromuscular blockade, the mean (+/- SD) plasma clearance, elimination half-life, and volume of distribution of vecuronium were 2.5 +/- 1.0 ml per kilogram of body weight per minute, 299 +/- 154 minutes, and 1.1 +/- 0.6 liters per kilogram, respectively. Prolonged neuromuscular blockade after the termination of long-term treatment with vecuronium is associated with metabolic acidosis, elevated plasma magnesium concentrations, female sex, and probably more important, the presence of renal failure and high plasma concentrations of 3-desacetylvecuronium.


Mutual interaction of histamine H3-receptors and alpha 2-adrenoceptors on noradrenergic terminals in mouse and rat brain cortex. Brain cortex slices were preincubated with 3H-noradrenaline and superfused with physiological salt solution containing desipramine. We studied the inhibition of the electrically evoked tritium overflow caused by histamine in the presence of alpha-adrenoceptor ligands (mouse and rat brain cortex), and the inhibition caused by talipexole (the former B-HT 920) in the presence of H3-receptor ligands (mouse brain cortex). In mouse brain cortex slices, the inhibitory effect of histamine on the tritium overflow evoked by 36 pulses, 0.3 Hz was not changed by the alpha 1-adrenoceptor antagonist prazosin, but increased by the alpha 2-adrenoceptor antagonist rauwolscine. When the current strength or the duration of electrical pulses was reduced to compensate for the increase in evoked tritium overflow produced by rauwolscine, the latter still enhanced the effect of histamine. The histamine-induced inhibition of tritium overflow evoked by 360 pulses, 3 Hz was not affected by the alpha 1-adrenoceptor agonist phenylephrine but attenuated by the alpha 2-adrenoceptor agonist talipexole. Finally, the inhibition by histamine of the tritium overflow evoked by 3 pulses, 100 Hz was attenuated by talipexole but not affected by rauwolscine. Conversely, the inhibitory effect of talipexole on tritium overflow elicited by 360 pulses, 3 Hz was slightly attenuated by the H3-receptor agonist R-(-)-alpha-methylhistamine but not affected by the H3-receptor antagonist thioperamide. In rat brain cortex slices, histamine only tended to inhibit tritium overflow evoked by 360 pulses, 3 Hz, both in the absence of alpha-adrenoceptor antagonists and in the presence of prazosin. However, histamine markedly inhibited the evoked overflow in the presence of rauwolscine.(ABSTRACT TRUNCATED AT 250 WORDS)


Alpha 2-autoreceptor-mediated modulation of tyrosine hydroxylase activity in noradrenergic regions of the rat brain in vivo. The physiological importance of brain alpha 2-adrenoceptors in controlling the activity of tyrosine hydroxylase in noradrenergic regions was investigated using the accumulation of 3,4-dihydroxyphenylalanine (DOPA) after decarboxylase inhibition as a measure of the rate of tyrosine hydroxylation (and synthesis of noradrenaline) in vivo. In the hypothalamus and cerebral cortex, clonidine (0.025-1 mg/kg, i.p.) decreased (18%-43%) and idazoxan (0.1-80 mg/kg, i.p.) increased (20%-73%) the synthesis of DOPA in a dose-dependent manner. Moreover, pretreatment with idazoxan (0.1 mg/kg) antagonized the effect of clonidine (0.1 mg/kg) in the hypothalamus. After treatment with reserpine (5 mg/kg, s.c., 18 h before decapitation) and depletion of noradrenaline, clonidine (0.5 mg/kg) continued to decrease (50%-55%) but idazoxan (20 mg/kg) failed to increase the synthesis of DOPA, which suggested the involvement of an alpha-auto-receptor mechanism. Acute treatments of rats (not exposed to reserpine) with a wide variety of adrenoceptor agonists such as guanfacine 6, B-HT920, xylazine, bromoxidine (1 mg/kg) and antagonists such as yohimbine, phentolamine, prazosin (10 or 20 mg/kg) resulted in significant decreases (15%-55%) or increases (21%-99%) in the synthesis of DOPA in both brain regions. However, other agonists (oxymetazoline, azepexole, tramazoline, methoxamine) and antagonists (tolazoline, dihydroergotamine, phenoxybenzamine, propranolol) did not modify the synthesis of DOPA. In the hypothalamus and cerebral cortex the effects of the drugs were consistent with the selectivity of alpha-adrenoceptor agonists and antagonists (except prazosin) for an alpha 2-adrenoceptor. The results also suggest that the alpha 2-autoreceptor that modulates the synthesis of noradrenaline in the rat brain appears to belong to the prazosin-sensitive alpha 2B-subtype.


[Changes in somatosensory evoked potentials in pharmacogenic myoclonia]. Transient increases of the early cortical somatosensory evoked potentials (SSEP) were observed in 9 patients who received antidepressant and/or neuroleptic treatment. All patients developed myoclonus, and 2 had grand mal seizures. Three cases--one 20-, one 17- and one 15-year-old patient--are presented in detail. Similar observations have been reported in elderly patients. Possible underlying mechanisms and the potential value of the SSEP in identifying and monitoring patients at risk of developing psychotropic drug-induced side-effects are briefly discussed.


L-glutamate inhibition of an inward potassium current in neonatal neurons from the nucleus of the solitary tract. Neurons isolated from the nucleus of the solitary tract (NTS) of 1- to 4-day-old rats were cultured for a study of the glutamatergic responses in this region of the medulla. Whole cell currents were examined under voltage clamp after 6-14 days in culture. An inwardly rectifying potassium current was identified in 107/174 cells. The presence of this K+ current diminished with time in culture from greater than 80% of the cells at day 6 to less than 30% of the cells after day 10. The current was inhibited by L-glutamate (IC50 = 10 microM).


MK-801, a non-competitive antagonist of NMDA receptor, prevents methamphetamine-induced decrease of striatal dopamine uptake sites in the rat striatum. We investigated the effects of MK-801, a non-competitive antagonist of NMDA receptor, on methamphetamine-induced decrease in dopamine (DA) uptake sites in the rat striatum. Repeated administrations of an escalating dose of methamphetamine (2.5, 5, 7.5, 10 mg/kg s.c. x2, every other day for a week) produced decreased DA uptake sites assayed by binding with [3H]GBR 12935 in the striatum. Co-administration of MK-801 and methamphetamine significantly prevented the methamphetamine-induced decrease in striatal [3H]GBR 12935 binding. Administration of MK-801 alone did not affect [3H]GBR 12935 binding. These results suggest that some neurochemical effects of methamphetamine may be mediated via mechanism involving excitatory amino acids.


Studies on the origin of rat hippocampal dihydroxyphenylacetic acid using microdialysis. With a dialysis probe implanted in the rat ventral hippocampus we have monitored effects on noradrenaline (NA) and dihydroxyphenylacetic acid (DOPAC) of the infusion through the dialysis probe of drugs acting at dopaminergic and noradrenergic presynaptic autoreceptors; clonidine and idazoxan produced changes in the extracellular concentration of both NA and DOPAC, whereas LY171555 and sulpiride had no effect on NA but produced changes in the concentration of DOPAC. The combined effect of clonidine and LY171555 on DOPAC was additive. Hippocampal DOPAC is therefore derived from both the noradrenergic and the dopaminergic projection to the hippocampus.


Receptor-coupled uptake of valproate in rat astroglial primary cultures. Various receptor ligands were investigated for their effects on the uptake of the antiepileptic drug valproic acid (VPA) in primary astroglial cultures from cerebral cortex of neonatal rats. After stimulation with the alpha 1-adrenoceptor agonist phenylephrine, 5-hydroxytryptamine (5-HT) or the glutamate receptor agonists glutamate, quisqualate and kainate, the Vmax and Km values for the drug transport increased. On the contrary, after exposure to the alpha 2-adrenoceptor agonist clonidine, Vmax and Km decreased. The effects were reversed in comparison to the control level in the presence of selective receptor antagonists. The data indicate a specific coupling between receptors and the uptake system for VPA. Furthermore, the results may have significant implications, as they suggest that receptors on astrocytes can be involved in the local regulation of drug transport in brain.


Cardiovascular responses to feeding in newborn piglets. Cardiovascular responses to feeding have been observed in several species during various periods of development and have been implicated in the development of cardiovascular regulation. In the rat, these responses are characterized by short-lasting, large increases in blood pressure (BP) and moderate increases in heart rate. These responses appear to be sympathetically mediated because pretreatment with ganglionic blockers eliminates the increase in BP associated with milk ingestion. The present study was designed to determine if similar cardiovascular responses occur during feeding in the newborn piglet. Piglets were obtained on postnatal d 2 and fed a milk diet via automatic feeder 6 times a day. On postnatal d 6, the piglets were instrumented with an external carotid artery catheter and an internal jugular vein catheter. On postnatal d 8 and 9, direct arterial BP and heart rate were recorded during feeding. BP responses to milk ingestion were immediate, and they reached a maximum increase of 50% above baseline on both test days and followed a response profile similar to that previously described in the 15-d-old rat. An increase in heart rate was also observed, reaching a maximum of 42% above baseline. The results show that early in life piglets have large cardiovascular responses to milk ingestion similar to those observed in young rats and human infants. These responses appear to model the cardiovascular responses to feeding observed in human infants and might be useful as a noninvasive method for assessing neonatal autonomic reactivity. These responses also have the potential to cause adverse effects in newborns already at risk for cardiovascular and cerebrovascular disease.


Synthesis and histamine H2-receptor activity of heterocyclic impromidine analogues. Analogues of the H2-agonist impromidine with unsubstituted or substituted aromatic or non-aromatic heterocycles instead of the 5-methylimidazole group were prepared via the benzoylguanidine method and tested for H2-agonistic and H1-antagonistic activity in the guinea-pig isolated right atrium and ileum, respectively. Compounds with unsubstituted 2- or 3-pyridyl, 2-pyrazinyl, or 5-pyrimidyl thioether portion proved to be about equipotent in the atrium (about 2-4x histamine). Highest potency was found in the 5-chloro-3-pyridylthioethylguanidine 8h, that is about 20 times more potent as an H2-agonist than histamine, corresponding to about 8 times the activity of the unsubstituted parent compound 8g. It is demonstrated by the piperidinyl- and morpholinylalkyl guanidines 8m-o that an aromatic ring is not required in the affinity-conferring moiety of H2-agonists (8n: 1.3x histamine). Replacement of the (5-methylimidazol-4-yl)methylthio group in the H2-antagonist cimetidine by halogenated pyridyl, pyrazinyl and pyrimidinyl thioethers resulted in compounds inactive as H2-antagonists, giving further evidence for differences in the structural requirements of the affinity-conferring portions of H2-agonists and antagonists and their mode of interaction with the receptor protein.


Age-dependent choice of sexual partners and the transmission dynamics of HIV in Sub-Saharan Africa. A mathematical model of the transmission of HIV-1 within heterosexual populations in Sub-Saharan Africa is described and its properties analysed. The model incorporates epidemiological and demographic processes and extends previous work in this area via the inclusion of age and sex dependency in rates of sexual partner change, and sexual partner choice dependent on age. Parameter assignments are made on the basis of current data on the transmission dynamics of HIV-1 and the demography of human populations in Africa. Both age-dependent rates of sexual activity and the sexual contact of males with females younger than themselves act to enhance the predicted demographic impact. With realistic parameter values, the model suggests AIDS is able to reverse the sign of population growth rates from positive to negative values over a timescale of a few decades. The sensitivity of this prediction is examined in relation to changes in the pattern of sexual contact between different age classes of females and males, different patterns of change in the age-dependent rate of sexual partner change, different assumptions concerning the doubling time of the epidemic in its early stages, and the relative efficiencies of viral transmission between men and women, and vice versa. The impact AIDS is predicted to have on the number of young and elderly persons as a fraction of the number of productive adults (the dependancy ratio) is examined under various assumptions concerning the weighting to be applied to mirror the burden imposed by the care of those with AIDS. The paper includes an assessment of the influence of the timing of changes in sexual behaviour, or the promotion of the use of condoms, on the predicted course of the epidemic. The paper concludes with a discussion of data needs and the model refinements required to more accurately mirror current understanding of the epidemiology of HIV-1.


Cholinergic interneurons in the feeding system of the pond snail Lymnaea stagnalis. I. Cholinergic receptors on feeding neurons. All the identified feeding motoneurons of Lymnaea respond to bath or iontophoretically applied acetylcholine (ACh). Three kinds of receptors (one excitatory, one fast inhibitory and one slow inhibitory) were distinguished pharmacologically. The agonist TMA (tetramethylammonium) activates all three receptors, being weakest at the slow inhibitory receptor. PTMA (phenyltrimethylammonium) is less potent than TMA and is ineffective at the slow inhibitory receptor, which is the only receptor sensitive to arecoline. At 0.5 mM the antagonists HMT (hexamethonium) and ATR (atropine) selectively block the excitatory response, while PTMA reduces the response to ACh at all three receptors. d-TC (curare) antagonizes only the fast excitatory and the fast inhibitory responses, but MeXCh (methylxylocholine) blocks the fast excitatory and slow inhibitory responses solely. For each of the feeding motoneurons, the sign of the cholinergic response (excitation or inhibition) is the same as the synaptic input received in the N1 phase of the feeding rhythm.


Cholinergic interneurons in the feeding system of the pond snail Lymnaea stagnalis. II. N1 interneurons make cholinergic synapses with feeding motoneurons. The N1 neurons are a population of interneurons active during the protraction phase of the feeding rhythm. All the N1 neurons are coupled by electrical synapses which persist in a high Mg/low Ca saline which blocks chemical synapses. Individual N1 spikes produce discrete electrotonic postsynaptic potentials (PSPS) in other N1 cells, but the coupling is not strong enough to ensure 1:1 firing. Bursts of N1 spikes generate compound PSPS in the feeding motoneurons. The sign (excitation or inhibition) of the N1 input corresponds with the synaptic barrage recorded during the protraction phase. Discrete PSPS are only resolved in a Hi-Di saline. Their variation in latency and number can be explained by variation in electrotonic propagation within the electrically coupled network of N1 cells. The excitatory postsynaptic potentials (ESPS) in the 1 cell are reduced by 0.5 mM antagonists hexamethonium (HMT), atropine (ATR), curare (d-TC) and by methylxylocholine (MeXCh), all of which block the excitatory cholinergic receptor (Elliott et al. (Phil. Trans. R. Soc. Lond. 336, 157-166 (Preceding paper.) (1992)). The 1 cell EPSPS were transiently blocked by phenyltrimethylammonium (PTMA), which is both an agonist and antagonist at the 1 cell excitatory acetylcholine (ACh) receptor (Elliott et al. 1992). The inhibitory postsynaptic potential (IPSP) in the 3 cell is blocked by bath applications of MeXCh and PTMA, which both abolish the response of the 3 cell to ACh (Elliott et. al. 1992). The effects of the cholinergic antagonists on the response of 4 cluster and 5 cells to N1 stimulation matches their response to ACh (Elliott et al. 1992). It is concluded that the population of N1 cells are multiaction, premotor cholinergic interneurons.


Cholinergic interneurons in the feeding system of the pond snail Lymnaea stagnalis. III. Pharmacological dissection of the feeding rhythm. The feeding activity of the pond snail Lymnaea stagnalis was stimulated by depolarization of a modulatory interneuron (SO) or of a N1 pattern-generating interneuron. The cholinergic antagonists phenyltrimethylammonium (PTMA), methylxylocholine (MeXCh), hexamethonium (HMT) and atropine (ATR) were applied at 0.5 mM in the bath and their effects on the rhythmic feeding pattern were monitored. Each of the antagonists slowed or blocked the feeding rhythm. The block was due to interference in the pattern generating network, not to disturbance of modulatory inputs. The experimental results favour a model in which the alternation of protraction (N1) and retraction (N2) phases occurs by recurrent inhibition. The results would be more difficult to explain on the reciprocal inhibition model. When all the N1 output was blocked, the N1 neurons fired rhythmic bursts endogenously.


Cerebellar cortex: its simulation and the relevance of Marr's theory. Marr's theory of the cerebellar cortex as an associative learning device is one of the best examples of a theory that directly relates the function of a neural system to its neural structure. However, although he assigned a precise function to each of the identified cell types of the cerebellar cortex, many of the crucial aspects of the implementation of his theory remained unspecified. We attempted to resolve these difficulties by constructing a computer simulation which contained a direct representation of the 13,000 mossy fibres and the 200,000 granule cells associated with a single Purkinje cell of the cerebellar cortex, together with the supporting Golgi, basket and stellate cells. In this paper we present a detailed explanation of Marr's theory based upon an analogy between Marr's cerebellar model and an abstract model called the associative net. Although some of Marr's assumptions contravene neuroanatomical findings, we found that in general terms his conclusion that each Purkinje cell can learn to respond to a large number of different patterns of activity in the mossy fibres is substantially correct. However, we found that this system has a lower capacity and acts more stochastically than he envisaged. The biologically realistic simulated structure that we designed can be used to assess the computational capabilities of other network theories of the cerebellum.


Modelling mechanically stable muscle architectures. This paper presents a planar architectural model for an activated skeletal muscle, with mechanical equilibrium throughout the muscle belly. The model can predict the shape of the muscle fibres and tendinous sheets as well as the internal pressure distribution in the central longitudinal plane (perpendicular to the tendinous sheets) of uni- and bipennate muscle bellies. Mechanically stable solutions for muscle architectures were calculated by equating the pressure developed by curved muscle fibres with the pressure under a curved tendinous sheet. The pressure distribution under a tendinous sheet is determined by its tension, its curvature and the tensile stress of the attached muscle fibres. Dissections showed a good resemblance of the architecture of embalmed muscles with those from our simulations. Calculated maximum pressures are in the same order of magnitude as pressure measurements from the literature. Our model predicts that intramuscular blood flow can be blocked during sustained contraction, as several experimental studies have indeed demonstrated. The volume fractions of muscle fibres and interfibre space in the muscle belly were also calculated. The planar models predict a too low volume fraction for the muscle fibres (about 45% for the bipennate models with a straight central aponeurosis, and about 60% for the simulated unipennate muscle). It is discussed how, in a real muscle, this volume problem can be solved by a special three-dimensional arrangement of muscle fibres in combination with varying widths of the tendinous sheets.


[Neuroleptic malignant syndrome--a case report]. The occurrence of a malignant neuroleptic syndromes accompanied by urinary retention under the treatment with fluphenazine and prothipendyl in a mentally disabled psychotic is reported. Early recognition of the syndrome and immediate termination of the neuroleptic treatment lead to its spontaneous remission. Subsequent neuroleptic treatment by clozapine was tolerated without further complications.


Effects of the novel NMDA receptor antagonist, CGP 39551, on field potentials and the induction and expression of LTP in the dentate gyrus in vivo. The effects of the novel competitive N-methyl-D-aspartate (NMDA) receptor antagonist, CGP 39551 [the carboxyethylester of CGP 37849; DL-(E)-2-amino-4-methyl-5-phosphono-3-pentenoic acid], on extracellular field potentials and long-term potentiation (LTP) induced in the dentate gyrus by stimulation of the perforant path were studied in anesthetized rats. CGP 39551 attenuated the population spike (PS) and excitatory postsynaptic potential (EPSP) amplitude of dentate field potentials, reduced the NMDA receptor-mediated component of train-evoked burst potentials, and prevented the induction of LTP. The decrease in PS and EPSP amplitude produced by CGP 39551 was observed mainly in non-potentiated synaptic populations; potentiated field potentials were only minimally affected by drug treatment. These results are consistent with receptors may contribute in a tonic manner to the state of dentate granule cell excitability. Finally, the differential modulation of potentiated and non-potentiated synapses by CGP 39551 suggests that a change in some properties of postsynaptic AMPA receptors is involved in the expression of LTP.


GABAB receptor-mediated inhibitory postsynaptic potentials evoked by electrical stimulation and by glutamate stimulation of interneurons in stratum lacunosum-moleculare in hippocampal CA1 pyramidal cells in vitro. Following micropressure application of glutamate (500 microM) in stratum lacunosum-moleculare (L-M), inhibitory postsynaptic potentials (glut-IPSPs) were recorded in CA1 pyramidal cells. These glut-IPSPs were blocked by tetrodotoxin (1 microM) and, thus, were probably generated by the activation of local interneurons. The effects of pharmacological antagonists on glut-IPSPs and on electrically-evoked early and late IPSPs were assessed in the same cells during the same application of the antagonist. Local application of the GABAB antagonist 2-OH saclofen (1-4 mM) reduced both glut-IPSPs and late IPSPs but not early IPSPs. In contrast, the GABAB antagonist phaclofen (20 mM) reduced late IPSPs but not early IPSPs but not early IPSPs or glut-IPSPs. Early IPSPs were blocked by the GABAA antagonists bicuculline and picrotoxin but late IPSPs and glut-IPSPs were not. Repetitive electrical stimulation depressed early and late IPSPs as well as glut-IPSPs, suggesting that interneurons activated with glutamate were also stimulated electrically. Thus, interneurons in str. lacunosum-moleculare appear to inhibit pyramidal cells via a GABAB receptor-mediated IPSP. The discrepancy in the pharmacological profile of the GABAB glut-IPSPs and of the GABAB late IPSPs may suggest the presence of two GABAB mechanisms in CA1 pyramidal cells.


Changes in extracellular glutamate concentration produced in the rat striatum by repeated ischemia. Evidence suggesting that ischemia-induced neuronal damage may be linked to an extracellular overflow of glutamate has accumulated, and previous studies have shown that repetitive ischemic insults may have a cumulative effect. The purpose of this study was to investigate changes in the extracellular glutamate concentration produced by repeated brief ischemic episodes of varied severity. Four consecutive 3- or 5-minute periods of bilateral hemispheric ischemia were produced in rats, each ischemic period followed by 27 minutes of reperfusion. Extracellular glutamate in the striatum was monitored using microdialysis, and the electroencephalogram and extracellular direct current potential were recorded in the same tissue site to assess the severity of ischemia. The results suggest that the kinetics of the increase in the extracellular glutamate concentration produced by a brief ischemic episode are similar, irrespective of whether it is a single insult or part of a repeated sequence. In all cases, the extracellular glutamate concentration increased throughout ischemia and returned to its preischemic level early during reperfusion. The pattern of changes in the ischemia-induced glutamate overflow during repetitive insults varied with the severity of ischemia, in common with the pattern of changes in the direct current potential, supporting the concept that ionic changes associated with anoxic depolarization are a major determinant of ischemia-induced glutamate overflow. There may be no cumulative effect of brief repeated episodes of ischemia on the extracellular glutamate concentration, even though repeated 5-minute ischemic episodes apparently caused progressive deterioration of ionic homeostasis in some cases.


Catecholamine synthesizing enzymes in 70 cases of functioning and non-functioning phaeochromocytoma and extra-adrenal paraganglioma. Immunohistochemical localization of the catecholamine synthesizing enzymes, tyrosine hydroxylase (TH), aromatic L-amino acid decarboxylase (AADC), dopamine-beta-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT), was investigated in 70 cases of functioning and non-functioning phaeochromocytomas comprising 52 of adrenal and 18 of extra-adrenal origin. Of 59 functioning tumours, 30 were mixed epinephrine and norepinephrine-producing (mixed type) and 29 were norepinephrine-producing tumours. TH, AADC and DBH were detected in all functioning phaeochromocytomas, but PNMT was limited to the mixed-type phaeochromocytomas. Non-functioning phaeochromocytomas were divided into two groups, comprising a complete type, which induced neither elevated plasma catecholamines nor their metabolites in urine, and an incomplete type which exhibited no elevated plasma catecholamines, but showed a slightly high urinary vanillylmandelic acid level. In the non-functioning complete-type tumours, immunoreactive TH was negative, but the incomplete tumours of the adrenal medulla had all four enzymes, and corresponded to a mixed-type phaeochromocytoma. AADC and DBH were present universally in all functioning and non-functioning tumours, including TH-negative tumours. TH is a rate-limiting enzyme of catecholamine biosynthesis and deficiency of TH is an important feature of extra-adrenal non-functioning phaeochromocytomas.


Immunohistochemical study of kuru plaques using antibodies against synthetic prion protein peptides. Prion protein (PrP) is a protein closely associated with the transmission of scrapie and Creutzfeldt-Jakob disease (CJD). Kuru plaques are composed of this protein. PrP33-35 is converted to protease-resistant PrP27-30 by proteinase K digestion. It has not yet been determined which of these PrPs is present in kuru plaques in vivo. Accordingly we synthesized two peptides (peptide-N and peptide-M) that, respectively, corresponded to the protease-sensitive and protease-resistant portions of PrP33-35, based on the amino acid sequence deduced from human PrP cDNA. These two synthetic peptides were used to immunize rabbits and produce antisera (anti-N and anti-M). Both antisera stained kuru plaques in a patient with Gerstmann-Sträussler syndrome and one with CJD. Peptide-N has an amino acid sequence which does not exist in PrP27-30. Staining of kuru plaques by the antiserum against peptide-N indicated that the entire molecule, including the N-terminal portion of PrP33-35, was deposited in the kuru plaques.


Beta-agonists and surfactant in eustachian tube function. The presence of surface tension lowering substances (surfactants) is demonstrable in the Eustachian tube (ET) and the middle ear, both in animals and in humans. In the lungs, beta-adrenoceptor agonists stimulate the secretion of surfactant; and it has been suggested that beta-agonists have a similar effect both in the ET and the middle ear, because opening of the ET is facilitated by the non-selective beta-agonist, isoprenaline in the rat, and by the beta 2-agonist, terbutaline, in humans. Two studies are described: In one, children with otitis media with effusion took terbutaline or placebo twice a day for two weeks and no significant differences were found between the effects of the two treatments; in the other study, it was shown that surfactant markedly facilitated the opening of the Eustachian tube. Lung surfactant prepared from pigs and instilled as a single dose into the middle ear of healthy rats reduced the air pressure necessary to open the Eustachian tube by as much as 15-20% for as long as the experiments lasted (i.e., around one hour). Thus, possibilities of facilitating the opening of the Eustachian tube do in fact exist.


Cue exposure and learning theory.

Cue exposure and learning theory. The implications are discussed for cue exposure treatment of four theoretical issues; (a) spontaneous recovery, (b) response competition, (c) generalization, and (d) the cognitive basis of conditioning. It is suggested that practical cue exposure treatment will not be as straight-forward as initial trials have suggested.