Determination of cocaine and benzoylecgonine in human amniotic fluid using high flow solid-phase extraction columns and HPLC. A new solid-phase extraction procedure for the determination of cocaine and benzoylecgonine in amniotic fluid, using high flow co-polymeric sorbents is reported. The recoveries of cocaine and benzoylecgonine within the range 0.1-1 mg/l were 95.7% and 50.3%, respectively. The use of high-flow sorbents allowed the easy extraction of amniotic fluid regardless of sample viscosity or physical nature. The use of these solid-phase columns provided many advantages over the more commonly used solvent extraction, including an increase in extraction speed and efficiency, reduced operator time, reduced solvent use and disposal volumes and exceptional extract quality. Further, the determination of amniotic fluid obtained from pregnant cocaine users may provide important information about handling of cocaine by the fetus at various gestational ages. The procedure was successfully applied to amniotic fluid from suspected cocaine abusers.


A matter of large body passing through a small hole: the holeproof out the window. A baffling case of fall-from-height is described focusing on aspects of a human body passing through a small hole, within a holeproof window. It is a classic example of an unsatisfactory outcome when a scene of death is modified adversely due to delay in the commencement of scene management. The operative factors may be entirely outside the control of scene investigators. The primary medical attendant is reminded of the forensic obligations at a scene of unnatural death. Reporting this case might encourage forensic practitioners having experience of a similar case to respond through this journal.


Early and late meningeal reaction to trauma after long-term brain death. We examined histologically the meninges adherent to traumatic lesions of a patient with brain death sustained for 101 days and observed both early and late reactions of wound healing at the same site of the dura mater. Some parts of the dura mater were thick and histological examinations revealed formation of new vessels and fibrosis with strong positive reaction for iron and fat staining. We also observed fresh haemorrhage and some cell infiltration in the dura and fresh haemorrhage in a small piece of necrotic brain tissue adhered to the dura mater, while other areas of the brain tissue were completely necrotic, enabling the sites of head injury to be localised. These observations suggested that the blood flow in the dura mater fluctuates due to a change of microenvironment, which probably causes repeated secondary petechial haemorrhages in the dura and its adherent necrotic brain tissue, even 101 days after brain death.


Widespread myocardial and pulmonary bone marrow embolism following cardiac massage. Widespread fatal massive bone marrow embolism of the coronary and the pulmonary arteries are described in a 71-year-old man with a respiratory disease. Cardiac massage was carried out during the cardiac arrest. In autopsy findings there were no fractures of the ribs or the sternum. The authors suggested that the cardiac massage was the most important predisposing factor for the bone marrow embolism.


Post-mortem toxico-kinetics of trazodone. Trazodone is a structurally unique bicyclic anti-depressant, said to be significantly less toxic than other anti-depressants following an acute overdose. We studied the tissue distribution and post-mortem redistribution of trazodone in two fatalities, one of which allowed comparison with trimipramine, a typical tricyclic anti-depressant. Case 1, a 53-year-old female weighing 72 kg, had femoral vein concentrations of trimipramine 5.5 micrograms/ml, trazodone 14.4 micrograms/ml and alcohol 107 mg%. Case 2, a 48-year-old female of 70 kg, had a femoral vein trazodone of 15.5 micrograms/ml and alcohol 34 mg%, with no other drugs detected. For case 1 and case 2 respectively, trazodone tissue concentrations were: skeletal muscle 7.3 and 9.0 micrograms/g; left and right lungs 13.3, 12.9 and 35.3, 40.1; myocardium, 30.9 and 28.9; kidneys 34.7 and 39.6; liver 73.7 and 82.4; fat 18.5 and 16.5; brain 48.6 and 20.9. For case 1 and 2, respectively, blood trazodone concentrations in 10 initial autopsy samples ranged from 13.7-17.3 and 14.4-16.9 micrograms/ml. Twenty-four and forty-eight hours later the respective ranges were 12.8-18.0 and 12.4-19.9 for case 1, 12.5-20.1 and 12.7-27.0 for case 2. By contrast, for trimipramine, blood concentrations at 0 time, 24 h and 48 hours ranged from 5.5-11.4, 5.2-14.3, and 4.2-18.2, respectively. We conclude that trazodone shows little preferential concentration in solid organs and consequently has relatively stable post-mortem blood concentrations with little drug redistribution artefact. Both the clinical pharmacokinetics and post-mortem toxicokinetics of trazodone differ significantly from the tricyclic anti-depressants.


Insulin modulation of chronotropic response to Adrenaline in diabetic dogs. In 8 unanesthetized dogs, 10-21 days post pancreatectomy, the cardiac chronotropic response to rapid infusion of a pharmacological dosage of Adrenaline was begun. During the subsequent month, the response was recorded electrocardiographically on 19 occasions. On 8 occasions, animals were treated with continuous intravenous administration of fluids and insulin up to the time of the test; on 11, insulin was omitted for 18 hours before Adrenaline injection. Insulin treated animals responded with the typical brief initial bradycardia, followed by some 2 minutes of ventricular tachycardia, and restoration of preinjection heart rate and electrocardiograph pattern within 5 minutes. On those occasions when insulin was omitted, the tachycardia was replaced by ventricular bradycardia. The altered chronotropic response of non-insulin treated dogs indicates impairment of their cardiac beta receptors.


Influence of paracetamol, sulfanilamide and ascorbic acid on the electrocatalytic glucose sensor. An electrocatalytic glucose sensor for in vivo application has been developed. The principle of measurement is based on the direct electrochemical oxidation of glucose at a platinum electrode without an enzymatic reaction. In an in vivo experiment with sheep the glucose sensor was tested with respect to its cross-sensitivity towards ascorbic acid, paracetamol and sulfanilamide. The influence of these substances could be reduced by an adapted calibration to such an extent, that the sensor performance could be ensured.


Protective effect of diltiazem hydrochloride on the occurrence of alloxan- or streptozotocin-induced diabetes in rats. This study demonstrated that 20 mg/kg of the Ca2+ channel blocker, diltiazem hydrochloride, administered by intraperitoneal injection 15 min before 200 mg/kg of alloxan given by the same route to induce diabetes, served to suppress disease onset completely in rats. Even though 48-h fasting promoted the onset of alloxan diabetes, 40 mg/kg of diltiazem hydrochloride completely prevented the occurrence of diabetes induced by intraperitoneal injection of 200 mg/kg of alloxan. Forty mg/kg of the same agent, however, failed to prevent the onset of diabetes induced by the intravenous injection of streptozotocin (50 mg/kg). From the fact that Ca2+ channel blockers such as nicardipine, verapamil and bepridil have a similar suppressive effect on the occurrence of alloxan diabetes, one may readily infer that this action is characteristic of Ca2+ channel blockers. Moreover, the results suggest the close connection of Ca2+ in the occurrence of alloxan diabetes in rats.


Endurance exercise training causes adrenal medullary hypertrophy in young and old Fischer 344 rats. The purpose of the present investigation was to determine the effects of endurance exercise training on adrenal medullary volume and epinephrine content in young (5 month) and old (23 month) female Fischer 344 rats. Animals from each group underwent 10 weeks of treadmill running (60 minutes per day, 5 days per week). 72 hours following the last training session animals were killed and the adrenal glands removed for subsequent analysis. Plantaris muscle citrate synthase activity increased with training in both young and old animals (39.8% young; 36.4% old). Trained animals had larger adrenal medullary volumes (48% increase in young, and 18% in old) than untrained controls. Trained animals also had higher total adrenal medullary epinephrine content (36% increase in young, and 24% in old). There were no differences in adrenal medullary epinephrine or norepinephrine concentration (micrograms/microliters medulla). It was concluded that the training-induced increase in adrenal epinephrine content is due to an increase in the size of the medulla, and not to a greater medullary epinephrine concentration. Furthermore, similar responses to training occur in both old and young animals.


Normal tissue plasminogen activator and plasminogen activator inhibitor activity in plasma from patients with type 1 diabetes mellitus. The fibrinolytic system was investigated in 38 patients (21 males and 17 females) affected by type 1 diabetes mellitus (18 free from complications, 10 with retinopathy, and 10 with autonomic neuropathy) and in 8 healthy controls. Two separate fibrinolysis-stimulating tests were done: standardized venous occlusion and 1-desamino-8-D-arginine vasopressin infusion. Plasma tissue plasminogen activator antigen and activity and plasma plasminogen activator inhibitor activity were measured. All the patients were in good metabolic control (mean HbA1c 7.4%, range 6.1-8.0%). No significant differences were observed either between the diabetic patients and the control subjects, nor among the subgroups of diabetic patients. The fibrinolytic system is probably not involved in type 1 diabetes mellitus.


The role of estrogen in the TSH and prolactin responses to thyrotropin-releasing hormone in postmenopausal as compared to premenopausal women. The basal and TRH (Thyrotropin-Releasing Hormone) stimulated TSH (Thyrotropin) and PRL (Prolactin) responses (incremental area; IA) to 200 micrograms TRH was studied in 13 pre- and 13 postmenopausal women of 60 years of age. Both groups consisted of healthy women, none had goiter and all were negative for thyroid autoantibodies. The serum levels of TSH, T3, T4 and SHBG (sex hormone-binding globuline) were in the normal range and did not differ significantly between the groups. There were no differences in basal TSH (1.3 +/- 0.5 vs 1.4 +/- 0.5 mIU/l) or PRL (6.4 +/- 2.7 vs 6.6 +/- 2.5 micrograms/l) or for PRL IA (498 +/- 126 vs 584 +/- 165) between pre- and postmenopausal women. However, for TSH IA there was a slight decrease (15%), but not significant, in the postmenopausal group compared to the premenopausal group (1630 +/- 598 vs 2067 +/- 893). In conclusion, a weak but not significant decrease in the TSH response to TRH in postmenopausal women may be explained by the lower endogenous estradiol level.


The origin of oestrone sulphate in normal and malignant breast tissues in postmenopausal women. Conversion of oestrone sulphate to oestrone has been suggested to make a major contribution to the level of oestrone found in breast tissues. In order to examine the ability of breast tissues to take up oestrone sulphate (E1S), 3H E1S or E1-35S was infused into postmenopausal women with advanced breast cancer. For 3 subjects infusion of 3H E1S was repeated after treatment with Danazol, a potential inhibitor of oestrone sulphatase activity. After infusion of 3H E1S significant levels of 3H E1S were detected in normal and malignant breast tissues (tissue: plasma ratios 0.14 +/- 0.13 and 0.24 +/- 0.12 respectively, mean +/- S.D., n = 5). Similar 3H E1S tissue: plasma ratios were detected after infusions of 3H E1 indicating that the 3H E1S detected in breast tissues after infusion of 3H E1S may have originated from the hydrolysis of 3H E1S in tissues other than the breast, with subsequent uptake and sulphation in breast tissues. After infusion of E1-35S no significant levels of radioactivity were detectable in normal or malignant breast tissues. Treatment with Danazol had no significant effect on tissue levels of 3H E1S or on the CRE1S E1 or MCR-E1S. It is concluded that oestrone sulphate, as such, is not taken up by breast tissues and that any contribution that oestrone sulphate makes to the oestrogen content of breast tissues will depend upon prior hydrolysis.


Pathomorphological findings in thyroid cancers of children from the Republic of Belarus: a study of 86 cases occurring between 1986 ('post-Chernobyl') and 1991. Recently, an impressive increase in malignant thyroid tumours has been observed among children less than 15 years of age living in the Republic of Belarus at the time of the nuclear accident of Chernobyl in 1986. More than half of these patients lived in the region of Gomel, nearest to Chernobyl. Because of the very short time interval between the accident and the tumour occurrence an independent review of the available histopathological material was done. Out of 101 cases diagnosed as thyroid cancers, we reviewed slides of 93 cases and agreed the diagnosis of malignancy in 92.5%. Of these tumours 96.5% were papillary carcinomas, 61.5% were moderately or poorly differentiated. Extrathyroidal extension was observed in 60.5%, regional lymph node metastases in 74% and distant metastases in 7%. One of the patients died from lung metastases. Our results confirm that the neoplasms increasingly diagnosed between 1986 and 1991 among children of this region are thyroid carcinomas. In addition, we correlate several histopathological findings with sex and age of the patients and other parameters, and compare the results with data from other studies.


Histological examination of first trimester spontaneous abortions: the impact of materno-embryonic interface features. Cytogenetic findings and placental histological features of 319 consecutive first trimester spontaneous abortions were retrospectively investigated. Correlation of cell culture results and microscopic examination based on conventional villous histological criteria showed an overall sensitivity of 45.1% for histology in detecting chromosomal anomalies. Discrepant cases, i.e. normal histology with unequivocal chromosomal anomaly and abnormal histological features suggesting a chromosomal anomaly according to the classical criteria but with a normal karyotype, were reviewed by two independent observers using extended histological criteria including features of the materno-embryonic interface. There was a significant (P < 0.001) increase of the sensitivity of histology to 66.4% for both observers after the second histological examination. Macerated specimens or incomplete specimens made of chorion laeve or maternal decidua only are difficult to evaluate, and represent the main cause of discrepancy between cytogenetics and morphology. The results of this study indicate that the sensitivity and specificity of microscopic examination in cases of early spontaneous abortion may be improved by adding features of the materno-embryonic interface to classical villous histological criteria.


The lymphoepithelial lesion of gastric low-grade B-cell lymphoma of mucosa-associated lymphoid tissue (MALT): an ultrastructural study. Lymphoepithelial lesions are a characteristic feature of primary, gastric low-grade lymphomas of mucosa-associated lymphoid tissue (MALT). The lymphoepithelial lesions in 12 such lymphomas have been examined by electronmicroscopy and immunohistochemistry. The lymphocytes present in these lesions are neoplastic centrocyte-like (CCL) B-cells and are morphologically and immunophenotypically similar to those of the surrounding lymphoma. Once the CCL cells penetrate the gastric glands, there is marked structural distortion and disruption of the epithelial cells which leads to their ultimate death. The close association of the neoplastic CCL cells and epithelial cells suggests the presence of a factor, an antigen or other receptor, on the plasma membrane of the latter through which these effects are mediated.


The peritubular myoid cells in the testes from men with varicocele: an ultrastructural, immunohistochemical and quantitative study. Ultrastructural and some immunophenotypic features of the peritubular myoid cells of testes from normal men and from men with varicocele were studied. The seminiferous tubules were classified into five types (a-e), related to the progressive degree of sclerosis measured as thickening of the lamina propria. In normal testes only type a and b tubules were found, whereas the testes from men with varicocele showed type b-e tubules. Myoid cells in tubule types a and b showed slender cytoplasmic projections with abundant, parallel arranged microfilament bundles and electron-dense bodies. In c tubules, the myoid cells showed the same ultrastructure. The myoid cells of tubules with advanced (type d) or complete (type e) sclerosis showed irregularly outlined nuclei, scant microfilament bundles and absence of electron-dense bodies. Immunostaining of myoid cells with anti-actin antibodies was intense in types a-c tubules and scant in types d and e. Immunostaining with anti-desmin antibodies was intense in tubules types a-d, but the immunoreactive cells in types c and d tubules were irregularly shaped and distributed and were scanty in tubule type e. Immunostaining with anti-vimentin antibodies was weak in types a-c tubules and intense in types d and e tubules. Quantitative studies revealed that, with the progression of sclerosis, the numbers of both actin- and desmin-immunoreactive cells per cross-sectioned tubule, and the surface area occupied by the immunostained portion of these cells, decreases while the number of vimentin-immunoreactive cells and their immunostained surface area increases.


Cribriform intra-tubular epididymal change and adenomatous hyperplasia of the rete testis--a consequence of testicular atrophy? We have observed an unusual change in the epididymal tubules, ranging from focal epithelial proliferation forming bridges, to a pronounced intra-tubular cribriform pattern of the epithelium. This often occurs in association with adenomatous hyperplasia of the rete testis which is an uncommon, usually incidental finding. Both processes appear associated with underlying testicular atrophy and may be related to local hormonal imbalance.


Lymph node findings in generalized mastocytosis. Lymph nodes from 21 cases of generalized mastocytosis were studied histologically to confirm or exclude mast cell infiltration, and to investigate their micro-architecture. Mast cell infiltrates were detected in 17 (80%) of the lymph nodes and were found mainly in the medullary cords and sinuses. Diffuse infiltration was seen in 14 cases and focal infiltration in three cases. The following pathological findings were frequently observed: germinal centre hyperplasia (n = 14), which is probably a nonspecific finding; and hyperplasia of small blood vessels, which sometimes resembled high endothelial venules (14), eosinophilia (8), plasmacytosis (7) and collagen fibrosis (6), all of which may well be related to the effects of mediators released by mast cells. Infiltrates of acute or chronic myeloid leukaemia were seen in six lymph nodes. Division of the cases into two prognostically different groups, i.e. systemic mastocytosis, in which the skin lesions of urticaria pigmentosa are present and the prognosis is favourable, and malignant mastocytosis, in which there is no cutaneous involvement and the prognosis is poor, revealed that all six lymph nodes exhibiting leukaemic infiltrates came from the malignant mastocytosis group; eosinophilia, plasmacytosis and fibrosis were seen significantly more often in malignant than in systemic mastocytosis, but blood vessel hyperplasia and germinal centre hyperplasia were encountered with the same high frequency in both groups; and mast cell atypia tended to be more pronounced in malignant mastocytosis; this diagnosis could therefore easily be missed without naphthol AS-D chloroacetate esterase staining.(ABSTRACT TRUNCATED AT 250 WORDS)


Benign epithelial neoplasms of the appendix: classification and clinical associations. The nomenclature of non-carcinoid epithelial proliferations of the appendix is confused and many of the terms used have no histogenetic basis. A classification based on the well-established diagnostic categories of colonic epithelial polyps has been proposed recently. We have applied this classification to 42 benign epithelial lesions of the appendix in order to determine its suitability for routine diagnostic use, and in order to determine the prognosis of patients with these lesions. All lesions could be classified as either hyperplastic, adenomatous, mixed hyperplastic/adenomatous or dilated appendices. Six cases were associated with a synchronous carcinoma of the colon with all types of appendiceal histology being represented. Follow-up of the remainder of the patients revealed two subsequent colonic carcinomas, at 3 and 6 years post-appendicectomy respectively. In both of these patients, the appendix had shown adenomatous epithelium. We suggest that adenomas of the appendix may have a similar prognostic significance to adenomas elsewhere in the large bowel.


Immunohistochemical localization of basement membrane type VII collagen and laminin in neoplasms of the head and neck. The distribution pattern of the basement membrane components type VII collagen and laminin, was studied immunohistochemically in normal human head and neck tissues and in a series of benign and malignant tumours from the same site. Using monoclonal antibodies, a basement membrane containing type VII collagen and laminin could be demonstrated beneath the epithelial cell layer in 16 normal head and neck tissues from different localizations. Unlike type VII collagen, laminin was also abundantly present around blood vessels and muscle fibres. With respect to 42 squamous cell carcinomas studied, type VII collagen and laminin were present in basement membranes surrounding small and large tumour fields, independent of the tumour grade. Type VII collagen was demonstrated in the cytoplasm of tumour cells in 36% of the cases, while the antibody to laminin displayed a basement membrane staining pattern mainly. Both antibodies showed a staining gradient in more than half of the cases, with strong staining in the centre of the tumour and weakening of the staining towards the tumour periphery. In a series of 22 salivary gland tumours consisting of 19 pleomorphic adenomas and three adenoid cystic carcinomas, the distribution pattern of type VII collagen and laminin was very heterogeneous. Laminin was present in 17 and type VII collagen in 10 of 19 cases of pleomorphic adenoma, mostly scattered throughout the tumour fields. In the tumours positive for type VII collagen areas with little or no positivity were also found. A correlation between type VII collagen positivity and the presence of basal cell keratin 14 positivity was noticed in the majority of cases.(ABSTRACT TRUNCATED AT 250 WORDS)


C-cell hyperplasia in secondary hyperparathyroidism. Calcitonin is a hypocalcaemia producing hormone and is secreted by C-cells of the thyroid. The current study was undertaken on a hypothesis that C-cell hyperplasia may develop in the secondary hyperparathyroidism of chronic renal failure in response to sustained hypercalcaemia. With an immunoperoxidase staining method for calcitonin, C-cell hyperplasia was noted in four of six cases of autosomal dominant polycystic kidney disease and in three of six cases of acquired renal cystic disease, an overall incidence of 58% compared with an incidence of 36% (five of 14) in cases of primary hyperparathyroidism with parathyroid adenoma. Thus, both primary and secondary hyperparathyroidism may trigger C-cell hyperplasia in an attempt to produce a hypocalcaemic effect.


[Composition and distribution of lipid and apolipoprotein in plasma lipoproteins of endogenous hypertriglyceridemia]. Lipids and apolipoproteins in plasma VLDL, IDL, LDL, HDL2 and HDL3 isolated by one-step density gradient ultracentrifugation from 7 subjects with endogenous hypertriglyceridemia (HTG) and 4 normalipemics were determined. HTG VLDL was enriched with cholesterol, and its triglyceride (TG), phospholipid (PL) and apo CII, CIII contents (mg/100 mg protein) were significantly higher than those in normal VLDL. ApoE content in HTG VLDL was prone to increasing, and apoB100 content had no apparent difference from that in normal VLDL. Compared with normal HDL2 and HDL3, the contents of total cholesterol (TC), apoAI, CII, and CIII in HTG HDL2, and apoCII, CIII in HTG HDL3 decreased. HTG HDL2 and HDL3 were rich in TG. By analysis of distribution of these lipids and apolipoproteins in various plasma lipoproteins, it was found that the abnormal composition of VLDL and HDL in HTG seemed to be a result of transport of TC, PL, and apoCII, CIII from HDL to VLDL. There was a significantly positive correlation between TC and apoAI, CII, CIII in HDL respectively, which indicated that apoCII and CIII were also associated with the alteration of HDL cholesterol. It is suggested that the elevated plasma VLDL-TG concentration in endogenous hypertriglyceridemia may induce abnormal redistribution of lipid and apolipoprotein among apoCII plasma lipoproteins, and and CIII may play an important role in these changes.


[Assay of genomic DNA homology among strains of different virulent leptospira by DNA hybridization]. Nick translation labelling technique was applied to the preparation of two 32P labelled genomic DNA probes from L. interrogans serovar Lai strain 017 and Leptonema illini strain 3055, respectively. Dot-blotting and Southern-blotting with DNA of five strains leptospira from different genus and species were performed. The results showed that certain differences among the L. interrogans, L. biflexa and Leptonema illini could be detected by endonuclease assay. L. interrogans strain 017 with L. biflexa strain Patoc I and Leptonema illini 3055 strain exhibited very little homology. L. interrogans strains 017, 601, and 245 from different serogroup and serovar had a high degree of homology. Leptonema illini strain 3055 showed little homology with L. interrogans and L. biflexa. Therefore DNA hybridization may be used as a tool for the identification and classification of leptospira.


[Investigation of microbicidal activity of neutrophil defensins against leptospires]. Defensins play an important role in oxygen-independent microbicidal mechanisms of neutrophils. They are effective against many bacteria, fungi and enveloped viruses. However, the effect of defensins upon leptospires has not been studied. In the present report, human defensins (i.e. HNP, a mixture of HNP1, HNP2 and HNP3 were prepared from human polymorphonuclear neutrophils by chromatography on Sephadex G-100 and then on Biogel P-10. Rabbit defensin NP1 was purified from rabbit peritoneal granulocytes by preparative acid urea polyacrylamide gel electrophoresis. By using the most-probable-number procedure, HNP and NP1 were tested in vitro for the killing of leptospira interrogans serogroup icteroheamorrhagiae serovar lai strain 017. NP1 was highly effective. When leptospires of strain 017 were incubated with 1 microgram/ml of NP1 at 30 degrees C for 4 hours, > 99% of these organisms were killed. HNP was less potent than NP1, and at 50 micrograms/ml, it killed > 90% of leptospires. As is also the case for the killing of bacteria, NP1 was active against leptospires in nutrient-free buffer, whereas HNP required the addition of glucose. The data suggest that defensins could play a major role in the killing of leptospires by neutrophils.


[Detection of leptospira by dot blot hybridization with photobiotin- and 32P-labelled DNA]. Photobiotin- and 32P-labelled DNA probes of L. interrogans sv. lai strain 017 were produced and the DNA and leptospires were dotted on the NC filter and hybridized. The results showed that photobiotin and 32P-labelled DNA probes could detect DNAs of homology. The smallest amount of DNA that could be detected with the probes were 5pg and 1pg, and the smallest numbers of pathogenic leptospires were 5 x 10(3) and 10(3), respectively. Nonpathogenic leptospires. L. biflexa sv. patoc strain Patoc 1, L. illini strain 3055, Escherichia coli, Bacillus aerogenes capsulatus, and Salmonella anatis, could not be detected by the probes. The study demonstrates that leptospires DNA probe could be produced by labelling the DNA with photobiotin. It has higher sensitivity and specificity and can be used for detection of leptospires in the field and clinic.


[The construction of rich genomic library of bovine Y chromosome]. According to the fundamentals of DNA renatured kinetics, we made a study in which genomic DNA from male cattle was completely digested with Sau 3A, while female DNA was sheared to an average size of 500 bp fragments. The Y derived DNA sequence rich library of bovine has been contracted with pUC19 plasmid as vector and JM109 as host bacteria by reassociation of male and female DNA. Male and female DNA probes, were used. The result of colony hybridization showed that out of 1000 recombinants analysed, 6 were found to be stronger signal with male probe. Analysis of Pvu' I digested DNA fragment revealed that most of the inserts were in the 90-300 bp.


[Thixotropic properties of whole blood in children with congenital heart disease]. The thixotropic parameters of whole blood in two groups of children with congenital heart disease (CHD) were measured. Group 1. cyanotic heart disease (CCHD), 20 cases; Group 2. acyanotic heart disease (ACHD), 30 cases. Fifty healthy children were controls matched with the patients in sex and age. Their thixotropic parameters were compared; the paired t-test was used. In the children with CCHD, the hematocrit (HCT), the yield stress (tau 0) the Newtonian contribution of viscosity (mu), the equilibrium value of the structural parameter (A), the apparent viscosity at 2.37 sec-1 (eta s) and the Non-Newtonian contribution of viscosity (eta s-mu) were significantly higher than those in corresponding control groups. In the children with ACHD, only the values of tau 0, eta s-mu, and eta s were higher than those in control groups. All of the thixotropic parameters in CCHD group were significantly higher than those in ACHD group. Thus we described quantitatively CHD in terms of thixotropy of blood. The thixotropic parameters of blood could be used as indexes of severity for pathologic changes of CHD.


[Noradrenaline fluorescence histochemical study on the locus coeruleus of kindling rat induced by coriaria lactone]. Fourteen male Wistar rats were divided into two groups. The experimental rats were injected with subconvulsive dosage of coriaria lactone (1 mg/kg) intramuscularly per 3.5 days. The controls were injected with normal saline. After 26 injections, the loci coeruleus of kindling rats were studied with the noradrenaline (NA) fluorescence histochemical technique at the time between seizures. The NA fluorescence could be clearly visualized under fluorescent microscope. The intensity of fluorescence was reflected by autoexposure-meter of the fluorescent microscope. The brighter the fluorescence, the shorter the autoexposure time. The intensity of NA fluorescence in the locus coeruleus of experimental animals was weaker than that of the controls. Since NA plays an inhibitory role in cerebral cortex, the decrease of NA, either induced by repeated injections of coriaria lactone or due to the time of sample taken after seizure, needs further study.


[Histochemical and image-analytic study of the rat locus coeruleus during status epilepticus]. Twenty-four adult male Wistar rats were used in this study. Status epilepticus was provoked in 10 rats by embedding coriaria lactone particle into the left cerebral motor cortex. In the controls were embedded particles without coriaria lactone. After 6 h of continuous seizure, the locus coeruleus was studied with the noradrenaline (NA) fluorescence histochemical technique and enzyme histochemical test for monoamine oxidase (MAO). The intensity of NA fluorescence was detected with fluorescent microscope autoexposuremeter and analysed with MIAS-200 Image Analyser. The study group showed a parallel increase of NA fluorescence as compared with that of the control group by both measurements. NA plays an inhibitory role in the cortex. Our data suggest that the increase of NA in locus coeruleus may be due to the reduction of NA release from axon terminal. Reduction in inhibition could be one of the mechanisms of seizure activity. The intensity of MAO was detected with MIAS-200 Image Analyser. The regulation of monoamine metabolism by MAO in the central nervous system and the increase of MAO activity in the continuous seizure group may be induced by the accumulation of NA in the locus coeruleus soma.


[Ultrastructural observation of SC1001-sodium on brain neurons kindled seizures by coriaria lactone in rabbits]. The ultrastructural changes of hippocampus and cerebral cortex neurons were derived from the rabbits kindled by coriaria lactone and from the kindled rabbits after treatment with SC1001 Na. The results of experiment showed that the hippocampus and cerebral cortex neurons in the kindled group had some degenerative changes, such as the swelling mitochondria, dilated rough endoplasmic reticulum and Golgi complexes when the injuries of neurons were not serious, but the seriously injured neurons were subjected to rupture of the cell membrane and solution of most organella, with only a small amount of degenerative organella. In the group treated with SC1001 Na, the ultrastructure of brain neurons demonstrated a tendency of recreation to normal which showed that SC1001 Na had cured many of the degenerative brain cells. This suggested that active treatment is very important for the epileptic patients.


[The purification and properties of LD5 from normal C57 mouse liver, H22 hepatoma and S180 sarcoma]. Type-A LDH (LD5), isolated from normal C57 mouse liver, H22 hepatoma and S180 sarcoma after a sequential ion-exchange and affinity chromatography, was examined to be quite pure. Studies on the enzyme kinetics and immunological properties showed that there were no differences in optimal pH, optimal temperature, subunit MW., isoelectric point between normal and malignant (H22 hepatoma and S180 sarcoma) LD5. Km to pyruvate decreased in malignant LD5 while LD5 content and percentage increased. Three LD5 antibodies raised against rabbits showed cross-reaction. These antibodies as probes are useful in the isolation of LD5-mRNAs from G57 mouse liver H22 hepatoma and S180 sarcoma.


[Isolation and identification of a strain of Pseudomonas SP. producing insoluble glucan hydrolase]. A strain, CIB871, isolated from the natural world can hydrolyze insoluble glucan(IG) produced by S. mutans. This organism has been identified to be a strain of Pseudomonas SP. It grows well at 30 degrees C. The optimum medium for producing insoluble glucan hydrolase (IGase) is composed of 0.3% peptone, 0.03% IG and M1 salt solution (NH4)2 SO4 1mg/ml, MgSO4 50 micrograms/ml, FeCl2 50 micrograms/ml, K2HPO4 0.5mg/ml). The IGase production reached maximum when cultured for 65-70 hours.


[Age-related change of synaptic number in the suprachiasmatic nucleus of the rat hypothalamus]. Numerical changes of the synapses in the hypothalamic suprachiasmatic nuclei (SCN) of rats at different ages were investigated with electron microscope, The population of the major SCN synapses formed with dendrite and total number of synapses were found to be reduced with advancing age. Compared with the young animal group, the synaptic number was statistically different from that in the adult or senescent group. As a result of these changes, the function of SCN might decline with aging.


[Effects of insulin on expression of oncogenes in CWE mouse brain]. By RNA dot blot hybridization, we observed the expression of c-myc, c-fos, Ha-ras and erbB genes in normal brain of CWE mouse after the injection of insulin. Transcription of the c-myc and c-fos genes is greatly increased, which peaks approximately 2 h after insulin stimulation, decreases in 6 h and returns to the initial levels within 48 h. The alteration in Ha-ras transcription appears more complex; its expression decreases first but increases subsequently. We also detected the expression of erbB gene which decreases after the injection of insulin. The results suggest that c-myc, c-fos, Ha-ras and erbB might be directly involved in growth control. Their protein products might play a role in intracellular signal transduction.


[Comparative study on activity of adenylate cyclase in normal human ovary with ovarian tumors]. It has been documented that the binding activity sites of human chorionic gonadotropin (HCG) receptor and kd in human ovarian tumors are different from those in the normal ovary. And some observations suggest that the HCG receptor depends on adenylate cyclase (AC) for its physiological functions. We studied the activity of AC in normal human ovary and ovarian tumors. Five human ovarian specimens and eighteen ovarian tumor specimens were obtained from women patients undergoing gynecological surgery. Ovaries were homogenized and sonicated. The homogenates were centrifuged at 1000 x g for 15 min. After sucrose density gradient ultracentrifugation (78000 x g, 4 h), the membrane fraction was collected from interface between 33% and 37%. The membrane protein approximately 10 micrograms, ATP 1 mmol/L, 3H-ATP 5 x 10(4) cpm, sulphydryl-ethyl alcohol 10 mmol/L, in a final volume of 200 microliters of Tris-HCl buffer (50 mmol/L), pH7.5, containing MgSO4 5 mmol/L, were incubated at 35 degrees C for 10 min. The reaction was stopped by boiling water bath for 3 min. The AC activity (U/mg): of human normal ovary, 67 +/- 8, of cystadenocarcinoma serous, 146 +/- 70; of cystadenocarcinoma mucinous, 289 +/- 83.


[Two pairs of particular structures of mandibular joints of mammalian sorex]. The mandibular joints of Chinese Anouroserex squamipes, spuamipes, MILNE-EDWARDS were examined by gross and microscopic studies. We discovered that there were two pairs of joints in these animals. The upper pair of joints, named lateral mandibular joints, were placed on both sides under the parietal bone. The lower pair of joints, named skull-base mandibular joints, were placed on both sides of the skull-base. These two pairs of joints could not be observed simultaneously in the same plane either sagittally or frontally. The lateral fossa and condyle were obliquely from outward, backward and upward to inward, forward and downward on both sides; the fossa looked like a groove concave downward, and the head of the condyles appeared in a cylindrical form. The lower fossae and condyles were transversely forward and inward from the lateral mandibular joints; the fossa looked like a shallow spoon concave upward, and the condyle appeared in a flat surface to fit the upward fossa. The sorex likes to dig holes on the ground to live in and search for insects in the soil to eat. The skull-base mandibular joints will support the jaw to counteract the digging force and protect the lateral mandibular joints from injury. This study has suggested that the morphology of the mandibular joints is adapted to their functional requirements during evolution.


[Circadian rhythm of blood pressure in renovascular hypertensive goats treated with captopril]. Blood pressure (BP) was recorded directly and automatically by a microcomputer aid system for 48 h in normotensive and Goldblatt hypertensive goats. By population-mean cosinor fitting, significant circadian rhythms were found for SBP and DBP in both groups of goats. The BP during nighttime was higher than that during daytime in our goats. An angiotensin converting enzyme inhibitor, captopril, was given to hypertensive goats with usual schedule of drug administration (25mg, t.i.d) or form of chronotherapy (62.5 mg, given before the acrophase of BP, q.n). BP significantly decreased throughout the whole day in both treated groups. But there was no statistical difference of cosinor parameters between the effects of BP in these two groups. BP could be decreased by the method of chronotherapy with less amount of drug and less frequency of drug administration.


[Effect of Chinese-made vesnarinone on experimental heart failure of dog]. Intravenous drip of sodium pentobarbital 6 mg/kg per min induced obvious heart failure of anesthetic dogs (n = 11) followed by an infusion of 0.25 mg/kg per min to maintain the heart failure state. The Chinese-made vesnarinone 3 mg/kg was injected, followed by an infusion of 0.1 mg/kg per min, or the solvent in the same volume, for 30 min. Vesnarinone increased significantly and instantly the cardiac output and left ventricular maximum + dp/dt, which almost recovered to normal at the end of the infusion and also significantly increased 30 min after administration. The positive inotropic effect of vesnarinone was not accompanied by an increase in the heart rate and the blood pressure. The results of our experiment reveal that the Chinese-made vesnarinone has a potent and relatively selective positive action on heart failure of dogs.


[Observation of the morphological genesis of pleural mesothelioma induced by asbestos in rats]. In order to observe the lesions of pleural mesothelia caused by asbestos, we injected asbestos fiber into the pleural cavity of Wistar rats. The result showed that there Was an obvious process for the morphological genesis of mesothelioma. Simple hyperplasia and stratified pleomorphic hyperplasia of mesothelial cells were found on the 30th and 106th day after the injection of asbestos fiber, respectively. The benign and malignant mesotheliomas were noted on the 300th day. Meanwhile, a two-way differentiation may be observed in the process of mesothelial hyperplasia.


[Aluminum and fluorine in blood and bone of rats fed on diet mixed with various contents of aluminum, fluoride or their mixture]. Wistar rats were divided into 8 groups:control, 300 ppm F, 130 ppm F, 300 ppm Al, 1200 ppm Al, 130 ppm Al + 130 ppm F. 300 ppm Al + 300 ppm F and 1200 ppm Al + 300 ppm F. The chemicals were mixed into the standard diet. The animals were fed on the diets for 12 weeks. Contents of F, Al, Ca and P in the blood (or serum) and humerus were determined at the end of 12 weeks. The results showed that the level of F in the blood and bone in the unadulterated F group was increased, especially F in the bone reached a level more than 10 times that of the control. In the 3 mixture groups, blood F and bone F were lowered, while blood F was restored to normal level, but bone F was not nevertheless, the results showed that Al was in antagonism to the absorption of F. In the unadulterated Al groups, blood and bone Al did not parallel with the amount of Al administered. The level of Al in the median Al group was higher than that of the high Al group. Taking the level of blood and bone Al as a measure, when different doses of Al were administered with F, in the low and median dosage of Al, F was in antagonism to Al absorption, but in case of high dosage of Al, F was in potentiation to Al absorption. In all the experimental groups serum P was elevated, but serum Ca was not disturbed. Bone Ca and P were decreased only in the 3 groups with unadulterated F as well as unadulterated and adulterated high dosage of Al. Mechanism of the nonlinearity of Al absorption vs Al dosage, as well as the dual effect of F on the absorption of Al was proposed.


[The toxicity of herbicide Asulam].

[The toxicity of herbicide Asulam]. We conducted a series of toxicity tests and short-term mutagenic assays of Asulam and 40% (W/V) sodium Asulam. It was found that the LD50 of Asulam with acute oral toxicity was 30000 mg/kg for mice, and the LD50 of sodium Asulam for mice and rats were equal (8250 mg/kg). The cumulative coefficient of sodium Asulam in Wistar rats was 9.42. None died from sodium Asulam absorbed via skin. Negative results were obtained in Ames test, Bacillus subtilis repair test and the micronucleus test. There was no significant difference between the control group and the treated groups in the chromosomal aberration rates of spermatogonia and primary spermatocytes of mice testis. The results indicated that Asulam should be regarded as a substance of low toxicity and low accumulation. No mutagenicity was observed in our experiment.


[A method of mercapto cotton/Ag-DDC determination for inorganic arsenic in seafood]. A method of mercapto cotton/Ag-DDC determination for inorganic arsenic in seafood was developed. It is reliable and simple--The coefficients of variation for 1.0-5.0 micrograms As (III), kelp and dried small shrimp samples are 1.5-5.6%, 4.4% and 9.5%, respectively. The recoveries of kelp and dried small shrimp samples are 82.0-102.6% and 83.0-97.1%, respectively. As compared with the results of the extraction method (Government standard) in the determination of inorganic arsenic levels in 10 kinds of seafood, the results of this simple method showed no significant difference.


[Determination of bendazac lysine by RP-HPLC]. Bendazac (BD) was separated on a CLC-ODS column, 150 x 6 mm id (Shimadzu), using methanol acetic acid 0.1 mol/L (67:33) as the mobile phase. The flow rate was 1.0 ml/min and the detection wavelength, 254 nm. The detection limit of BD was 0.1 ng (R/N, 3:1), which was determined by the peak area measurement using an external standard method. The calibration curve was linear in the range of 5-10 micrograms (r = 0. 9998). The average recovery of BDL was 99.46 +/- 0.59% (n = 9). This method has been applied satisfactorily to the determination of BDL samples.


[A study on the pathogenicity of Helicobacter pylori in chronic gastritis and peptic ulcer disease]. Gastroendoscopic biopsy specimens from 366 patients were stained with HE, Warthin-Starrys or Giemsa and mucin histochemical methods. Positive rate of Helicobacter pylori (HP) was 73.8% in chronic gastritis. Positive rates of HP in gastric ulcer disease were 88.2%, 91.9%, and 11.1% at the near and distant mucosa of ulcer and in duodenitis, respectively. Positive rates of HP in duodenal ulcer disease were 81.5%, 24.6% and 7.2% at the pyloric-antral area and at the near and distant mucosa of duodenal ulcer, respectively. The number of HP in active inflammation was higher than that in inactive inflammation (P < 0.05). The HP almost lived in the neutral mucin. There was no statistical significant difference between near and distant mucosa of ulcer (P > 0.05). HP might play an important role in the pathogenesis of chronic gastritis, and it might aggravate the peptic ulcer disease.


[Alveolar soft part sarcoma: a clinicopathologic and immunohistochemical study of 13 cases]. Thirteen cases of alveolar soft part sarcoma were studied clinicopathologically and by the PAP technique antisera against desmin, myoglobin, S-100 protein, neuron-specific enolase (NSE). We suggested, light microscopically, the main points for diagnosis and differential diagnosis of alveolar soft part sarcoma. Immunohistochemically, the tumor cells reacted positively for desmin (five cases), myoglobin (three cases) and NSE (four cases). No immunoreactivity for S-100 protein was observed. Similar results had been reported by others. No definite conclusion about histogenesis of alveolar soft part sarcoma could be drawn from the small number of cases in this study.


[Hepatic segmentectomy using microwave tissue coagulator]. Hepatic segmentectomy using a microwave tissue coagulator guided by intraoperative ultrasonography is a new operative procedure, which our research unit was the first to start using from 1990. Up to now we have performed this kind of operation with success in 26 cases. Our results suggested that the new procedure simplified the original operation and greatly reduced the risk of hemorrhage and iatrogenic spread of the cancer cells during operation. Besides, this operation as a kind of definite anatomic hepatectomy can minimally resect the tumor bearing tissue in a radical fashion, while maximally preserve the tumor-free tissue of the liver.


[Measurement of T-lymphocyte subsets in bronchial alveolar lavage fluid on smokers and patients with lung cancer]. The measurements of T-lymphocyte subsets (as expressed by, CD3 CD4 and CD8) in the peripheral blood and bronchial alveolar lavage fluid (BALF) on 30 cases of lung cancer, 26 cases of smoker and 25 cases of nonsmoker have been done. The results showed that there existed no differences in the peripheral blood of the above said subsets of lymphocyte. In BALF the percentage of CD3 in all the lymphocytes did not show any significant difference among the three tested groups, either (P > 0.05). But the percentage of CD4 and the ratio of CD4/CD8 manifested the following peculiarity: patients with lung cancers < smokers < nonsmokers (P < 0.01). On the contrary, the percentage of CD8 showed just the opposite: patients with lung cancer > smokers nonsmokers (P < 0.01). It was suggested that the cellular immunity as shown in the peripheral blood did not correspond with the findings in the BALF. The cellular immunity of the lungs was decreased both in patients with lung cancer and smokers, but more severely in the group of lung cancer patients. Smokers who have had changes of above said subsets of lymphocytes in the lungs may develop lung cancer. As the lung cancer advances, it may suppress body immunity and in turn enhance the cancer growth. Both the cause and the effect are interrelated. Therefore, the provocative agents for cellular immunity may act as one of the adjunctive therapies for patients with lung cancer. Giving up smoking should play an important role in recovering or promoting the immunity of the lungs and decreasing the incidence as well as improving the prognosis in patients with lung cancer.


[Cost-effectiveness analysis of short-term course and regular course of antithyroid drug therapy for Graves' disease]. One hundred and- eighteen newly diagnosed patients with Graves' disease were treated by tapazole for 6 months (short-term course) and followed up for another 12 months. Forty three percent remission rate was found in this group. A regular course of antithyroid drug therapy for 1.5-2 years with 50% remission rate was taken as control. Cost-effectiveness analysis was made to compare the cost in the two different kinds of therapy. The results showed that the total costs of the treatment per 100 cases were 17,746 yuan for the short-term therapy and 30,708 yuan for the regular therapy, with an average of 412.7 yuan and 614.2 yuan per case respectively. In comparison with the short-term therapy, the regular course could remit 7 more cases at a cost of 12,962.40 yuan, with an average of 1851.80 yuan per case. Therefore, the cost was high by prolonged course of therapy to increase slightly remission rate, although it could remit a few more cases. This study suggests that six-month treatment is preferable for those who live in the rural or remote area where the economy was less developed. A longer course of therapy may be unnecessary for those who have been treated by antithyroid drugs for 6 months or longer and are predicted to obtain a possible prolonged remission.


[Female pseudohermaphroditism with a phallic urethra--a case report]. Female pseudohermaphroditism with penile urethra caused by virilizing adrenal tumor in the mother is rare. A case is reported in this article. After operation the diagnosis was verified pathologically. Exposure of a female fetus to endogenous or exogenous androgens before the seventh or eighth week of fetal age may result in male external genitalia. It is emphasized that any cryptorchid phenotypic male born to a virilized mother should be proved by sex chromatin and sex chromosomes to exclude pseudohermaphroditism and that in any case of unexplained female pseudohermaphroditism one should explore the possibility of a maternal virilizing tumor.


[Metastatic tumor of posterior fossa].

[Metastatic tumor of posterior fossa]. Twenty-seven cases of metastatic tumor of posterior fossa were presented in this paper. Of the patients, 20 were males and 7 females; their age ranged from 20 to 68, and 89% of them were over 40 years of age. The primary foci found were bronchopulmonary carcinomas (7 cases), rhinopharyngeal carcinomas (3 cases), and cancer of the liver (1 case), but in 16 cases the primary foci were not found. All of these patients presented symptoms and signs of obviously increased intracranial pressure, and most of them had the signs of cerebellar and cranial nerves' lesions. Ventriculorgraphy and brain CT scanning were important procedures in the diagnosis, and MRI was most valuable in establishing the diagnosis and localization of posterior fossa metastatic tumors. Twenty-six patients underwent operation. The short-term follow-up study showed an improvement in 25 cases. There was one death. The surgical treatment of posterior fossa metastatic tumor was emphasized. Radiotherapy and chemotherapy were discussed.


[Reduction mammaplasty].

[Reduction mammaplasty]. Twenty-eight breasts of 15 patients with macromastia underwent reduction mammaplasty from 1982 to 1989. We followed up these patients postoperatively for 6 months to 7 years. The follow-up time for 8 patients was over 1 year, and 4 patients over 5 years. And 3 patients labored and lactated. These 15 patients were satisfied with this operative results. The operative technology was based on Pitange's method. This method improved the site of the nipple, transposition of nipple-areola complex, and design of dermal pedicle, so that it had better effects in the breast shape, breast fixation and incision scar concealed. We suggest that the purpose of macromastia treated in reducing volume, improving breast shape, preserving lactating function. This paper also discusses the methods for nipple site, nipple-areola complex transposition, breast resection and mastopexy.


Origin of changes in the epigastric impedance signal as determined by a three-dimensional model. The impedance technique can be used for the noninvasive monitoring of the stomach, with the epigastric impedance signal being a function of the position and configuration of the electrodes. The changes observed could be due to meal resistivity, meal volume and contractions of the gastric smooth muscles. The effect of these various factors on the epigastric impedance signal was determined for several electrode configurations using a three-dimensional model of the abdomen. When the voltage sensing electrodes are located close to the current electrodes, the signal varies linearly with meal volume. The relationship between meal resistivity and the epigastric impedance signal is nonlinear. The impedance signal varies linearly with the contractions of the circular smooth muscles of the stomach.


Calculation of Doppler spectral power density functions. A volume integral method for the calculation of Doppler ultrasound spectral power density (spd) functions is described. Axisymmetric flow in a circular tube with a power law velocity profile is assumed. The spd function is regarded as a probability density function for scatterer velocity, and the assumptions under which this is justified are considered. It is shown that the spd function is independent of Doppler angle except in the presence of wall reflection effects. A coordinate system centered on the beam is used and this enables the integrals to be easily formulated for arbitrary beams. Irregularly shaped and nonuniform beams can be treated. For the common flow and beam patterns, which exhibit symmetry, the volume integrals can often be reduced to a single integral and evaluated directly. The method is applied and the spectra are calculated for various different cases. Results are obtained for uniform rectangular and circular insonating beams, and for nonuniform beams with Gaussian, jinc, and sinc profiles. The effects of narrow beams and wall reflection are shown. The method may be readily applied to other beam and flow patterns, and extension to more complicated situations is also discussed.


Adaptive filter for event-related bioelectric signals using an impulse correlated reference input: comparison with signal averaging techniques. Many bioelectric signals result from the electrical response of physiological systems to an impulse that can be internal (ECG signals) or external (evoked potentials). In this paper an adaptive impulse correlated filter (AICF) for event-related signals that are time-locked to a stimulus is presented. This filter estimates the deterministic component of the signal and removes the noise uncorrelated with the stimulus, even if this noise is colored, as in the case of evoked potentials. The filter needs two inputs: the signal (primary input) and an impulse correlated with the deterministic component (reference input). We use the LMS algorithm to adjust the weights in the adaptive process. First, we show that the AICF is equivalent to exponentially weighted averaging (EWA) when using the LMS algorithm. A quantitative analysis of the signal-to-noise ratio improvement, convergence, and misadjustment error is presented. A comparison of the AICF with ensemble averaging (EA) and moving window averaging (MWA) techniques is also presented. The adaptive filter is applied to real high-resolution ECG signals and time-varying somatosensory evoked potentials.


A comparative study of simultaneous vibromyography and electromyography with active human quadriceps. Vibromyographic (VMG) signals, which are low-frequency vibration signals generated during muscle contraction, were studied in comparison with electromyographic (EMG) signals recorded simultaneously during isometric contraction of the human quadriceps muscles. The comparison was accomplished by evaluating the averaged root mean squared (rms) value, mean frequency (MF), and peak frequency (PF) of the VMG and EMG signals for four muscle contraction levels at joint angles of 30 degrees, 60 degrees, and 90 degrees. The four contraction levels, namely 20, 40, 60, and 80% of maximum voluntary contraction (MVC), were estimated and controlled by the torque readings of a Cybex II dynamometer. It was found that the VMG and EMG under the same conditions on the same muscle group are in general equally sensitive to the levels of muscle contraction. Results show that the rms value of the VMG signal increases linearly, in a manner similar to the EMG rms/%MVC relationship, with increasing muscle contraction levels. Furthermore, the study indicates that the averaged MF (6-24 Hz) and PF (9-19 Hz) of the VMG signals are much lower than the MF (75-109 Hz) and PF (40-80 Hz) of the EMG signals. The slopes of MF/%MVC curves for the VMG and EMG are approximately the same for 60 degrees and 90 degrees joint angles (approximately 3.1 Hz per 20% MVC for VMG and approximately 2.6 Hz per 20% MVC for EMG).(ABSTRACT TRUNCATED AT 250 WORDS)


Phase delay of pulmonary acoustic transmission from trachea to chest wall. The frequency-dependent propagation time, or phase delay tau (f), of sonic noise transmission from the trachea to the chest wall was estimated over the 100-600 Hz frequency range using a phase estimation technique from measurements performed on eight healthy subjects. Since tau (f) can be greater than one period of the input signal at frequencies greater than 100 Hz, the unambiguous phase estimate at 100 Hz was used as a starting-point to determine the phase angle H(f) and tau (f) at higher frequencies under the constraint that the spectra did not exhibit large point-to-point discontinuities. The resulting tau (f) range of 0.9-4.1 ms is consistent with sound propagation to the chest wall through both airways and surrounding parenchyma. The frequency and spatial dependence of tau (f) indicates that with increasing frequency more sonic energy travels further into the branching airway structure before coupling into the parenchyma. These results suggest that information concerning distinct regional lung structures may be obtained by probing the system acoustically over selected frequency bands.


Fuzzy control of mean arterial pressure in postsurgical patients with sodium nitroprusside infusion. We developed a fuzzy control system to provide closed-loop control of mean arterial pressure (MAP) in postsurgical patients in a cardiac surgical intensive care unit setting by regulating sodium nitroprusside (SNP) infusion. The fuzzy controller, originally expert-system-based, was analytically converted to ten nonfuzzy control algorithms, which reduced execution time dramatically. The core of the control algorithms was a nonlinear proportional-integral (PI) controller whose proportional gain and integral gain adjusted continuously according to error and rate change of error of the process output. The gains became larger when process output was far from desired setpoint and smaller when process output was close to desired setpoint, resulting in more dynamic and stable control performance than the regular PI controller, especially when a linear process with time-delay or a nonlinear process was involved. The control algorithms, encoded in C programming language, were implemented to control MAP in patients. Preliminary clinical results showed that the average percentage of time in which MAP stayed between 90% and 110% of the MAP setpoint was 89.31%, with a standard deviation of 4.96%. These were calculated based on 12 patient trials, with total trial time of 95 and 13 min.


Adaptive control of multiplexed closed-circuit anesthesia. This paper describes the design of an adaptive closed-circuit anesthesia controller based on a multiplexed mass spectrometer system. The controller deals with measurement deterioration caused by measurement delay and rise time through a long catheter as well as long sampling times due to the multiplexed measurements. Measurement data are extrapolated between sampling periods to increase the estimation convergence rate. A multiple-step-ahead predictive control algorithm is used to calculate intermediate control inputs between sampling intervals. Simulations are used to validate the designed controller.


A worst-case optimal parameter selection model of cancer chemotherapy. An optimal parameter selection model of cancer chemotherapy in which two system parameters are unknown is formulated as a worst-case optimal parameter selection model. The model assumes that the unknown parameters lie within a known set. The system constraints must be satisfied over this entire set, and the objective function minimized in the worst case. The continuous dependence of the objective function and the system constraints upon the unknown parameters can be removed, making a numerical solution tractable. For the data considered it is proven that a cure is impossible no matter what the values of the unknown parameters in the parameter set. The optimal policy is shown to be relatively low dose intensity for the majority of the treatment, with the remaining drug delivered towards the end of the treatment interval.


Evaluation of microwave and radio frequency catheter ablation in a myocardium-equivalent phantom model. A highly localized burst of energy applied to the myocardium via a transvenous catheter-mounted power source can be used to destroy endocardial tissue regions which mediate life-threatening arrhythmias. In the past, high-voltage direct current pulses, radio-frequency (RF) current, and laser light have been used as energy sources. In this paper, the use of 2450 MHz microwave energy applied via a miniature coaxial cable-mounted helical coil antenna designed specifically for this application was investigated as a means to increase the treated volume of cardiac tissue in a controllable and efficient manner during ablation. Using an array of fiber optic temperature probes implanted in a saline-perfused, tissue-equivalent gel phantom model designed to simulate the myocardium during ablation, the heating pattern from the microwave antenna was characterized and compared to that induced by a commercial RF electrode catheter at 550 kHz. Effects of variable contact angle between the heat source and heart wall were assessed in terms of the radial penetration and overall volume of heated tissue. Heating patterns from the RF electrodes dropped off much more abruptly both radially and axially than the microwave antenna such that the volume of effectively heated tissue was more than ten times larger for the microwave antenna when the heat sources were well-coupled to the tissue, and more than four times larger for the microwave antenna when the sources were angled 30 degrees away from the tissue surface.


Clinical application of an active electrode using an operational amplifier. An active electrode (d10 mm, t6 mm) is presented, that functions as an impedance transformer (an input impedance > 10 G omega, an output impedance < 1 omega) by means of which we can derive surface EMG without any skin preparation and paste. This electrode was compared with a conventional one, and it was ascertained that the electrode could be replaced with the conventional one, and, moreover, it was preferable because it required less preparation time, and was less affected by environmental noise.


Estimation of the spatio-temporal correlations of biological electrical sources from their magnetic fields. Quasi-static electromagnetic systems, such as those found in biological systems, produce electric and magnetic fields whose temporal and spatial correlations reflect the source correlations in a straightforward manner. These fields can be noninvasively measured, providing information about the coherence properties of the source, which may directly represent ordered physiological processes of the organism. The description "biocoherence" will be adopted here to refer to the manifestation of the coherence in the magnetic measurements of these sources due solely to physiological processes. In this paper a general formulation linking the spatial and temporal coherence of measurable magnetic fields with the corresponding spatial and temporal coherence of the inaccessible current sources is derived in the quasi-static model. A method for reconstructing the spatial and temporal coherence of the source distribution is then presented. Such coherence maps would be useful descriptors of physiological processes occurring over time and space, and would represent more information than an image of the current sources frozen in time, or even a temporal sequence of such images.


Knowing the patient: one aspect of clinical knowledge. This paper analyzes the concept "knowing the patient" which was identified in a qualitative study of expert nursing practice during ventilator weaning of adult patients. The concept signified a cognitive and relational process by which the study participants determined salient aspects of a particular patient situation, while at the same time demonstrating their credibility and eliciting patient trust. The paper describes the clinical judgments, decisions, actions and patient outcomes that ensue from knowing the patient. This analysis offers a contextually specific description of nurses' clinical reasoning that illustrates a dimension of expert clinical practice from actual rather than simulated clinical content.


Quality of life of hospitalized persons with AIDS. This study explores quality of life from the viewpoint of Persons with AIDS (PWAs) who were interviewed during periods of hospitalization. Quality of life was viewed as the patients' perception of the relative effectiveness of a chosen or ascribed management style in solving the practical problems associated with being ill. Six management styles used by the respondents to improve their quality of life were identified. Results of this study suggest that nurses can improve PWAs' quality of life by supporting their respective management styles.


Spiritual well-being, religiousness and hope among women with breast cancer. The purpose of this study was to clarify spiritual health by examining the role of spiritual well-being (SWB), religiousness and hope in spiritual health. This was accomplished by obtaining questionnaire information from a convenience sample of 175 women diagnosed with breast cancer. Patients classified as intrinsically religious were found to have significantly higher scores on SWB than did those classified as extrinsically religious. There was no difference in hope scores between intrinsically religious and extrinsically religious patients, although hope was positively correlated with SWB. Existential well-being, a component of SWB, was the primary contributor of hope. The two major prognostic variables, stage of disease at diagnosis and number of positive lymph nodes, did not predict any of the scores.


Exploring empathy: a conceptual fit for nursing practice? After three decades, the efficacy of empathy in the clinical setting remains undocumented. Recently, concerns have been raised that the concept may be inappropriate and even harmful to the nurse-patient relationship. An analysis of the concept indicates that empathy consists of moral, emotive, cognitive and behavioral components. By tracing the integration of this concept into nursing, we suggest that empathy was uncritically adopted from psychology and is actually a poor fit for the clinical reality of nursing practice. Other communication strategies presently devalued, such as sympathy, pity, consolation, compassion and commiseration, need to be reexamined and may be more appropriate than empathy during certain phases of the illness experience. Directions for future research are suggested.


A theory of care-seeking behavior.

A theory of care-seeking behavior. Although much research has focused upon why people do and do not engage in recommended health behaviors, there is a need to develop more accurate theories to explain and predict engagement in health behaviors. Because health behaviors differ in important ways, it could be most fruitful to understand one type of health behavior, such as secondary prevention behavior. This paper proposes a theory of care-seeking behavior (CSB), based on a theory of general behavior by Triandis. Other popular theories about health behavior (i.e., Health Belief Model and Theory of Reasoned Action) also are reviewed. Empirical support for the variables identified in the theory of CSB is presented, drawing from the literature on secondary prevention for cancer. The theory of CSB is applied to the situation of seeking care for cancer symptoms. Directions for future research based upon this theory are delineated.


Portrayal of nurses in advertisements in medical and nursing journals. This investigation examined the content of advertisements in medical and nursing journals to determine if the images of nurses reflect the roles nurses play in health care. The method used was content analysis. Thirty-five nursing journals and 48 medical journals yielded 313 different advertisements picturing nurses. Data were analyzed using descriptive statistics, chi-square, correlation coefficients, and interpreted for overall impressions of the portrayals. Nurses are portrayed as sex objects, ornaments and as handmaidens to physicians. The findings demonstrate a freezing of the image of nurses in the print media.


Attitudes of nurse managers and assistant nurse managers toward chemically impaired colleagues. The purpose of this research was to determine attitudes among nurse managers and assistant nurse managers toward impaired colleagues in a descriptive correlational study method, using the Perceptions of Nursing Impairment Inventory. The study revealed no significant differences in attitudes between groups; assistant nurse managers demonstrated a more disciplinary orientation toward impairment within nursing. Both groups tended to have supportive attitudes toward impaired colleagues. Racial/ethnic origin had the most influence on nurse managers' attitudes toward chemically impaired colleagues. The Philippine/Oriental group demonstrated a stronger need to know when a colleague is impaired or receiving treatment, exhibited less belief in the treatability of impairment and displayed a stronger belief in impairment as a personality weakness.


Nurses' job satisfaction: are there differences between foreign and U.S.-educated nurses? This article reports the results of a job satisfaction survey administered to foreign-educated and U.S. nurses at six New York City public hospitals. Although a comparison of results for foreign-educated nurses on temporary visas (N = 322) and U.S. nurses (N = 535) revealed demographic, education and work differences, no differences in level of satisfaction were found between the two groups. Cultural and work status differences that may have affected these results are discussed.


Nursing chronotherapeutics: a conceptual framework. Nurses frequently make decisions about when treatments and actions are performed. The nursing concern driving this review is the timing of nursing activities to optimize desired and minimize untoward effects. A nursing conceptual framework is proposed that highlights individual and environmental factors, as they relate to rhythmic responses; as well as places within the framework for nursing actions based on customary and usual temporal patterns.


Esther Lucile Brown--a memorial.

Esther Lucile Brown--a memorial. Esther Lucile Brown, who died in 1990 at the age of 92, was a social anthropologist at the Russell Sage Foundation for more than 30 years. Among her contributions were ground-breaking studies of the professions and stimulation of the development of medical social science. Her research on nursing stimulated professionalization and nursing education's move into the university. The accuracy of her research findings on nursing and psychosocial aspects of patient care led many to assume that she was a nurse. This memorial focuses on her contributions and personal impact on friends and colleagues.


[Recent findings on the pathogenicity of Entamoeba histolytica]. Entamoeba histolytica is the causative agent of human amoebiasis. During recent years, research in amoebiasis has concentrated on two subjects: 1. the dual manifestation of the infection as harmless colonization of the intestinal cavity or pathogenic tissue invasion and 2. the molecular analysis of functions of E. histolytica that are considered essential for pathogenicity. Besides epidemiological studies and isoenzyme analyses, molecular genetics have revealed additional evidence that two genetically distinct forms of E. histolytica do exist, named "pathogenic" and "nonpathogenic" forms, respectively. Both can infect humans but only the "pathogenic" form is able to invade the tissue and cause disease whereas the "nonpathogenic" is not. Questions remain open about the mechanism that triggers "pathogenic" E. histolytica to become invasive and about the molecules that are involved. Current data indicate that at least three functions of the amoebae are considered essential for pathogenic tissue invasion. Pathogenicity is viewed as a result of 1. adherence of the amoeba to host cells, predominantly mediated by a galactose- and N-acetylgalactosamine-inhibitable lectin, 2. killing of host cells by a pore-forming peptide known as amoebapore, and 3. proteolysis of the host's extracellular matrix mediated by cysteine proteinases. Structural detailed molecular analysis including cloning of the corresponding genes have led to a better understanding of the function of these proteins.


[New views on the pathogenesis and diagnosis of toxoplasmosis]. T. gondii is one of the most occurring human pathogenic parasites in Europe. While the majority of immunocompetent individuals with T. gondii infection do not present clinical symptoms, congenital toxoplasmosis and reactivation of a latent infection in immunocompromised patients (i. e. patients with AIDS) are of high clinical relevance. A classification of T. gondii isolates is not available so far, although it was possible to demonstrate strain differences by the use of several methods, i. e. by using monoclonal antibodies. T. gondii seems to be able to infect any mammalian cell. Host cell-derived as well as parasite-derived factors seem to be important for the contact between host cell and parasite and the subsequent internalization. Following invasion, T. gondii is located within a parasitophorous vacuole that does not fuse with lysosomes. The multiplication rate of these obligately intracellular growing parasites decreases during conversion from the tachyzoite stage to the bradyzoite stage. Finally, the bradyzoites-harbouring cysts persist for the lifetime of the host. Reconversion from bradyzoites to tachyzoites may occur in immunocompromised patients. Probably, IFN-gamma is involved in this process. In addition to serological methods, direct detection of T. gondii using PCR or demonstration of circulating antigens might be routinely used as diagnostical tools in the future. Determination of specific IgA antibodies, which can be evaluated using the immunoblot technique, seem to be important for early serological diagnosis. The use of recombinant antigens might be helpful in future diagnosis to circumvent discrepancies between serological test results which could have resulted from strain-specific differences.


[Malaria: immune mechanisms and immunization]. In the 1990s, malaria worldwide is still the most important infectious disease. In endemic areas mostly children carry the highest burden of morbidity and mortality. Nevertheless an increasing incidence in adults can be expected. Patterns of disease and immunity within a population may be related to host parasite interactions and recent advances in immunology have contributed to a better understanding at the molecular level. Humoral and cellular responses play a major part in the immunity as well as immunopathology of malaria. Due to their extensive adaptive modulation, it will be extremely difficult to expel malaria parasites from their ecological niche. Most approaches of immunization targeted at different parasite stages, interfere with the acquisition of natural immunity and should thus be pursued with great care if implemented in the field.


[The vir-regulon of Streptococcus pyogenes: coordinate expression of important virulence factors]. Streptococcus pyogenes (group A streptococci; GAS) expresses important virulence factors like the antiphagocytic M protein, the complement factor-inactivating C5a peptidase and the immunoglobulin-Fc-binding proteins on its surface. The corresponding emm, scpA, and emm-related (fcrA, ennX) genes are adjacently encoded on the genome. They are coordinately in trans regulated by the positive regulatory VirR factor. The responsible virR gene is also located within this segment of the genome which was called vir-regulon. There are at least three different types of organization of the vir-regulon. A frequently encountered type is the "Large vir-regulon". It comprises from 5' to 3' the following genes: virR, fcrA, a relatively small emm, ennX, and a 4.6 kb version of scpA. Another common type is the "Small vir-regulon", which contains a virR deviating in its 3'-region, a relatively large emm, and a 3.5 kb version of scpA. The "Unusual vir-regulon" is less frequently detected. It closely resembles the small one, but harbors an additional 3 to 4 kb DNA fragment between emm and scpA, occasionally encoding an emm-related gene. The type of vir-regulon encoded by a GAS strain correlates to its serotype, its M class, and its expression of serum opacity factor. The structural genes of the vir-regulon are expressed at a high level during growth in exponential phase, under anaerobiosis, and at body temperature. The sensor molecule which modulates VirR activity according to these environmental conditions has not yet been detected.(ABSTRACT TRUNCATED AT 250 WORDS)


[The role of antibiotics in the management of verotoxin-associated hemolytic anemia syndromes]. Significant improvements of dialysis techniques and the supportive treatment of the hemolytic uremic syndrome (HUS) during the last three decades do not veil the fact that causal therapy is not yet feasible. This holds true for the classic HUS associated with infections by verotoxin-(VT-)producing E.coli (VTEC) as for the majority of the much less frequent "atypical" forms. The influence of antimicrobial agents on production of verotoxins produced by clinical VTEC isolates was examined. Co-trimoxazole significantly increased the total yield of toxin. In contrast, ciprofloxacin, lincomycin and gentamicin caused significant reduction in toxin yields. The pathogenetic and therapeutic relevance of this finding is not yet known. Analysis of the clinical literature for the postulated relation between antibiotic treatment and development of HUS or its impact on the severity of the disease reveals a controversial picture. Based on the dynamics of the disease, the in vitro findings, and reports on unfavourable outcomes after treatment, it is concluded that antibiotics are not indicated in most cases of the enteropathic HUS or other VTEC infections. Antibiotic prophylaxis has neither been proven to be efficacious nor safe for the prevention of secondary cases during VTEC outbreaks. Apart from the implementations of hygienic measures, prospective studies on the role of antibiotics seem clearly warranted. Possible future strategies may include the design of immunological therapeutic concepts.


Variants of the mucosal mast cell line (RBL-2H3) deficient in a functional membrane glycoprotein. We have isolated and characterized subpopulations of the rat mucosal mast cell line, RBL-2H3, carrying either high or low density of a glycoprotein, recently established as mast cell function-associated antigen (MAFA, Ortega et al., 1991), on their surface. These populations were investigated in order to better define the involvement of the MAFA in coupling the immunological stimulation of mast cells to mediator release. The MAFA density on the cell surface of the deficient subpopulation was less than or equal to 10-20% that of the parental population and this phenotype was found to be stably maintained for several months. In contrast, the MAFA-enriched cells had maximally twice the number of copies per cell surface than that of the parental population and this phenotype was less stable. Significantly, low copy number of MAFA on the cell's surface was accompanied by a markedly different secretory response, i.e. (i) a considerable decrease in the secretory response to the Fc epsilon RI-mediated stimulus (ii) a marked enhancement of the ionomycin induced secretion. In order to gain insight into the causes for this decrease in cellular response to the Fc epsilon RI-mediated stimulus, we measured the amplitudes of several biochemical processes which are assigned to the stimulus-secretion coupling cascade. The Fc epsilon RI-mediated uptake of 45Ca2+ by the MAFA-deficient cells was considerably lower than that of the parental and MAFA-enriched cells. Similarly, these cell's Fc epsilon RI-induced rise in [Ca2+]i (both the initial transient as well as the sustained elevation), was markedly lower than that of the parental line and the MAFA-enriched cells. Moreover, the low initial transient rise in [Ca2+]i was found to be correlated with the decrease in Fc epsilon RI-mediated IP3 levels. We therefore examined the cell's content of the phosphatidyl-inositides hydrolyzing enzyme, phospholipase C gamma 1. This was found to be similar in the parental line and in its derived subpopulations. However, PLC gamma 1 activation, as measured by the time course of phosphorylation of its tyrosines, showed a marked difference: while PLC gamma 1 tyrosine phosphorylation, in the parental cells, was only transient (detected already 1 min after antigen addition and declined afterwards to basal levels at ca. 10 min), in the MAFA-deficient cells, tyrosine phosphorylated PLC gamma 1 was also observed 1 min after antigen addition, yet showed no decrease with time in its phosphorylation intensity for up to 30 min.(ABSTRACT TRUNCATED AT 400 WORDS)


Inhibition of murine erythroleukemia cell differentiation by normal and partially deleted c-myc genes. In our study of normal and partially deleted myc genes we found that N-myc, similarly to L-myc, can substitute for c-myc and inhibit MEL cell differentiation. All of the known putative functional domains of c-myc seem to be required for this inhibition. It is conceivable that c-myc inhibits differentiation by a mechanism that is related to its normal role in the cell, possibly by regulating transcription of genes involved in growth promotion. As was previously found for all of the other known activities of c-Myc, the HLH and LZ dimerization motifs are absolutely necessary for inhibition of MEL cell differentiation. Heterodimerization of Myc with Max or Max-like proteins could be a prerequisite for such inhibition. It is, therefore, of interest to study the regulation of max in MEL cells expressing normal and deregulated myc genes.


Calcium signalling by the high affinity macrophage Fc gamma receptor requires the cytosolic domain. Hematopoietic cells express multiple receptors which bind the Fc domain of IgG. We utilized transfection of COS-1 cells, a cell line which lacks endogenous Fc receptors, to study the expression and function of Fc gamma RI, the high affinity Fc gamma receptor in the absence of other Fc gamma receptors. Fc gamma RI was efficiently expressed in transiently transfected COS-1 cells as measured by flow cytometry and the binding of IgG sensitized RBCs (EA). In addition, analysis at the single cell level demonstrated that individually transfected COS-1 cells release cytosolic free Ca2+ [(Ca2+)i] upon activation with anti-Fc gamma RI antibody. The calcium response required Fc gamma RI cross-linking. COS-1 cells transfected with mutant Fc gamma RI lacking the cytosolic domain expressed Fc gamma receptors and bound EA as well as wild type receptors, but failed to induce an increase in [Ca2+]i. These data indicate that Fc gamma RI in the absence of other Fc gamma receptors mediates a calcium signal and that the cytoplasmic domain of Fc gamma RI contains the elements required for calcium dependent signal transduction.


Induction and function of Fc epsilon RII on YT cells; possible role of ADF/thioredoxin in Fc epsilon RII expression. The regulation of low-affinity Fc receptor for IgE (Fc epsilon RII) and the characteristics of both membrane and soluble forms of Fc epsilon RII were studied using YT cell line. We found that YT cells, a human NK like cell line, expressed Fc epsilon RII after IL-1 stimulation. Cross-linking of Fc epsilon RII on IL-1-stimulated YT cells as well as the transfectant of Fc epsilon RII-cDNA (YTSER) resulted in the up-regulation of IL-2R alpha (p55/Tac). A 59 kDa protein phosphorylated at tyrosine residues was co-immunoprecipitated with Fc epsilon RII from YTSER lysate using H107 anti-Fc epsilon RII mAb. YTSER not only expressed Fc epsilon RII on their surface but also secreted soluble form of Fc epsilon RII (sFc epsilon RII/sCD23; IgE binding factor). Affinity purification revealed that sFc epsilon RII released from YTSER is heterogeneous and consisted of several proteins differing in molecular weight. Both EBV+ B cells and HTLV-1+ T cells are high producers of ATL derived factor (ADF)/thioredoxin (TRX) and express Fc epsilon RII and IL-2R alpha respectively. To clarify the mechanism of Fc epsilon RII and IL-2R alpha induction by ADF/TRX, we examined the effect of ADF/TRX on the bindability of nuclear factor kappa B (NF-kappa B), which is known to regulate IL-2R alpha gene expression. In the gel shift assay, ADF/TRX was shown to enhance the bindability of NF-kappa B to its responsive element.


Soluble Fc gamma R (sFc gamma R): detection in biological fluids and production of a murine recombinant sFc gamma R biologically active in vitro and in vivo. Soluble forms of receptors for the Fc portion of IgG (sFc gamma R) were detected in biological fluids from mice and humans. In mouse bearing tumors, circulating amounts of sFc gamma R increased concurrently with tumor growth. Tumors secreting IgG2a, IgG2b or IgG3 led to a 5- to 10-fold increase in serum sFc gamma R levels whereas tumors secreting IgG1, IgGA or other types of tumors (non Ig B cell tumors, T cell lymphoma and a melanoma) increased 2- to 3-fold the levels of circulating sFc gamma R. In the human, sFc gamma R were also detected in whole unstimulated saliva. Levels of sFc gamma RII and of sFc gamma RIII were variable and did not seem to depend on the dental status of the individuals. Finally, a murine recombinant sFc gamma R (rsFc gamma R) composed of the two extracellular domains of Fc gamma RII was produced by culture of transfected L cells in bioreactors. The purified rsFc gamma R was found to inhibit antibody production in vitro in anti-SRBC responses and by cultures of small B cells stimulated by anti-IgM antibodies in the presence of IL-4 and IL-5. Moreover, the i.p. injection of this material into adult mice immunized with SRBC led to a decrease of IgG antibody production by splenocytes, as measured by a hemolytic plaque assay, and in serum, as measured by antigen-specific ELISA.


Two distinct regions of the mouse beta Fc gamma R gene control its transcription. The low-affinity receptors for the Fc portion of IgG (Fc gamma RII and Fc gamma RIII) are born by most of the immunocompetent cells and mediate a wide spectrum of biological activities. Macrophages, mast cells and lymphocytes express the type II Fc gamma R whereas the type III Fc gamma R is expressed on macrophages, mast cells and NK cells. In mice, the beta Fc gamma R gene codes for Fc gamma RII and the alpha Fc gamma R gene codes for the ligand-binding Fc gamma RIII alpha-chain. We have previously demonstrated that the methylation of the 5' region of these genes control their expression. In the present paper, we investigate the role of two unmethylated regions of the beta gene, the promoter and the third intron, in the control of its transcription. We show, by using two cell lines representative of B and mast cells, that different promoter fragments determine, in these two cell types, the transcription of the beta Fc gamma R gene. The third intron of the beta Fc gamma R gene contains sequences, which, introduced upstream to homologous or heterologous promoter, inhibit the transcriptional activity of these promoter. Thus, in B cells and in mast cells, the transcription of the beta Fc gamma R gene is controlled by two distinct regions of the gene.


Autocrine regulation of murine B lymphocyte growth by an IgM antibody. Culture supernatants of LPS-stimulated murine B lymphocytes are able to inhibit the growth of freshly isolated splenic B cells via an IgM antibody. The binding specificity of this IgM is not yet defined, but appears to be a B lymphocyte surface structure distinct from membrane immunoglobulin, MHC class II antigen, transferrin and Fc gamma receptors, and B220. The regulatory autoantibody allows the normal progression of early, but not late steps in the cycle of polyclonally-stimulated B lymphocytes and does not affect the increased antigen-presenting capacity of activated B cells. Therefore, this autoregulatory cycle is apparently ubiquitous and may be a major component of B lymphocyte homeostasis under physiological, as well as pathological conditions. Moreover, these findings bring into focus a possible regulating role of B lymphocytes in the humoral immune response.


Restriction mechanisms of B cell regulation by a physiological IgG-anti-immunoglobulin autoantibody. Immunization of LEW rats with strongly histoincompatible BN blood cells induces, in addition to anti-donor antibody, a broadly reactive IgG autoantibody which binds to IgG and IgM molecules (IgG anti-Ig). Minute amounts of affinity purified IgG anti-Ig (0.2 pg/10(6) cells) suppress the antibody production in vitro of antigen receptor (AgR)-stimulated B cells derived from rats of the same strain. The suppressive antibody is also active in the whole serum IgG fraction. Importantly, anti-Ig-induced suppression is governed by restriction mechanisms: only AgR-occupied B cells are affected, the suppression is cell cycle dependent, and maximum suppression is obtained at an optimum IgG concentration. Treatment of rats in vivo with 0.8 mg Ig-anti-Ig (whole IgG fraction) along with allogeneic cells resulted in nearly complete suppression of the anti-donor antibody response. Possible mechanisms of B cell suppression by IgG anti-Ig are crosslinking of AgR with FcR, or cocapping of the two receptors with sterical interaction as a consequence of their separate occupation. Both alternatives lead to the release of an inactivating signal.


Macrophage-bound C3 fragments as adhesion molecules modulate presentation of exogenous antigens. The involvement of complement in the response to T cell dependent antigens is generally accepted, however the mechanism has not been clarified. We compared the T cell response in vitro, using antigen-pulsed macrophages from normal and genetically C3-deficient guinea pigs, and show, that C3-fragments fixed covalently to the surface of the antigen-presenting cells are involved in the triggering of responder T cells. Binding of guinea pig C3-specific mAb to oil-elicited, OVA- and PPD-pulsed macrophages of C3D guinea pigs is reduced compared to normal cells, while the expression of Ia antigens is the same. C3-like peptides can be immunoprecipitated only from the lysate of oil-elicited normal cells. These C3-fragments are fixed to the cell-membrane via ester-bonds, since they are released upon treatment with hydroxylamine. In comparison with normal cells, the antigen-presenting capacity of macrophages derived from C3D animals is strongly impaired in cultures containing 10% normal guinea pig serum. A further impairment is observed in cultures with 10% C3D guinea pig serum. Two of the tested C3-specific mAb inhibited antigen-induced T cell proliferation in a dose-dependent manner. Our data point to the importance of C3, as a bivalent molecule, having the capacity to facilitate the cooperation between the antigen-presenting cell and the responder T lymphocytes.


Dynamic physical interactions of plasma membrane molecules generate cell surface patterns and regulate cell activation processes. Molecular interaction and transmembrane signal transducing events generate a very dynamic and ever changing "pattern" in the plasma membranes. Lymphocytes, the key functional elements of the immune system, are eminently suited to be the primary targets to investigate these proximity, mobility, or other physical-chemical changes in their plasma membranes. Recently, a number of experiments suggested that processed peptides from antigens can bind specific components of MHC molecules (Elliott et al., 1991). This is certainly a way to alter their structure. Cell surface patterns of topological nature, assembly and disassembly of oligomeric receptor structure like the IL-2 receptor have been investigated by sophisticated biophysical techniques. The dynamic changes in the two-dimensional cell surface pattern and intramolecular conformational changes within this "larger" macro-pattern may have a strong regulatory role in signal transducing and intercellular recognition processes. Recent data on these problems are presented together with brief and critical discussions.


Detection of cytokine receptors by high-sensitivity immunofluorescence/flow cytometry. Cytokines have profound effects on cells, and act through receptors which need only be at low concentrations (around 100 copies per cell) to transmit activation signals. The detection of such low concentrations is possible using monoclonal antibodies and fluorescence/flow cytometry, but only by using specialized techniques. The best results so far have been obtained using biotinylated second antibody followed by phycoerythrin-streptavidin, and batches of these reagents have to be carefully selected. Analysis of the fluorescence is best done using 546 nm excitation from a mercury arc lamp, but 512 nm excitation from an argon-ion laser can also be used. With appropriate alignment, instruments with 488 nm fixed-wavelength lasers can give sensitivity almost as good as the 546 nm system. Working at high sensitivity, background levels also increase, particularly for B lymphocytes. Background staining can be reduced to acceptable levels by blocking the two major mechanisms for non-specific binding. Applications of these methods to the detection of cytokine receptors on normal and malignant cells are reviewed.


In vivo and in vitro death of mature T cells induced by separate signals to CD4 and alpha beta TCR. To investigate whether a clonal deletion mechanism is responsible for the mature T cell tolerance that may be induced in vivo by TCR signal to anti-CD4 (H129.19 mAb) coated cells, we analyzed the T cell repertoire in anti-CD4 mAb treated BALB/c mice by flow cytometry following TCR signals through anti-alpha beta TCR mAb or SEB superantigen. Lymph nodes showed a strong reduction in the CD4+/CD8+ cell ratio, and a selective clonal loss of CD4+ V beta 8+ cells 4d following anti-alpha beta TCR or SEB injection, respectively. Following lymph node cell activation in a short-term in vitro assay with SEB or anti-V beta 8 mAb, a selective elimination of CD4+ V beta 8+ cells was again detected, and DNA fragmentation analysis disclosed a cell death by apoptosis. These findings suggest that TCR triggering transduces an apoptotic signal into CD4+ mAb saturated cells that in turn leads to specific holes in the mature T cell repertoire.


Targeting of anti-tumor responses with bispecific antibodies. T cells can be induced to specifically lyse tumor cells with bispecific antibodies containing anti-T cell receptor mAbs crosslinked to anti-tumor mAbs. Such "targeted cytolysis" requires that the target cell be bound directly to the cytotoxic cell. In addition, targeted T cells mediate a second activity, the secretion of factors that can block the growth of both tumor target cells and bystander tumor cells. When given to nude mice bearing intraperitoneal human ovarian carcinoma, targeted human T cells cause the rapid removal of most tumor cells from the peritoneum, and markedly prolong the times of survival of treated mice. The efficacy of targeted T cells for treating human cancer is currently being tested in clinical trials.