Lack of evidence for a high-affinity sarcosinamide carrier or a catecholamine carrier in Calu-1 lung-cancer cells, HT-29 colon-cancer cells, and DHF fibroblasts. We have previously demonstrated that uptake of the amino acid amide sarcosinamide by the glioma cell line SK-MG-1 occurs via the catecholamine carrier that accommodates epinephrine (Km = 0.284 mM; Vmax = 0.154 nmol/10(6) cells/min). Sarcosinamide chloroethylnitrosourea (SarCNU), a new anticancer agent that exerts increased in vitro antitumor activity against gliomas as compared with BCNU (bis-chloroethylnitrosourea), the standard agent of choice, competitively inhibits sarcosinamide uptake by SK-MG-1 cells [inhibition constant (Ki) = 3.26 mM]. Using radiolabeled N-[3H]-sarcosinamide, we determined the transport of sarcosinamide in HT-29 colon-cancer cells, in Calu-1 lung-cancer cells, and in normal foreskin DHF fibroblasts. Sarcosinamide transport was linear for up to 1 min at 22 degrees C. In HT-29 cells and DHF fibroblasts, the uptake of sarcosinamide followed Michaelis-Menten kinetics of carrier-mediated transport. In HT-29 cells the Michaelis constant (Km) was 2.76 +/- 0.1 mM and the maximal velocity (Vmax) was 2.03 +/- 0.1 nmol/10(6) cells/min, whereas in DHF fibroblasts the respective values were 6.58 +/- 3.90 mM and 12.08 +/- 8.20 nmol/10(6) cells/min. In these two cell lines, neither epinephrine nor leucine significantly reduced sarcosinamide transport. In Calu-1 cells there was no evidence of carrier-mediated transport of either sarcosinamide or epinephrine. These nonglial cell lines lack a high-affinity catecholamine carrier. The increased cytotoxicity of SarCNU in gliomas may correlate with the presence of a high-affinity catecholamine carrier.


Phase II study of cisplatin as a 5-day continuous infusion with vindesine plus recombinant human granulocyte-colony-stimulating factor in the treatment of advanced non-small-cell lung cancer. A total of 36 patients with advanced non-small-cell lung cancer (NSCLC) were treated with a combination of 5-day continuous i.v. infusion of cisplatin (25 mg/m2 daily), bolus infusion of vindesine (3 mg/m2) on days 1 and 8, and s.c. injection of recombinant human granulocyte-colony-stimulating factor (2 micrograms/kg daily) on days 6-21. Treatment was repeated every 3-4 weeks. Responding patients with stage IIIA or IIIB disease received chest radiation therapy (50-60 Gy) after this treatment. One complete response and 23 partial responses were observed, for an overall response rate of 66.7% (24/36; 95% confidence limits, 51.3%-82.1%). The median duration of response was 5.7 months and the median overall survival was 10.1 months. WHO grade 3 or 4 leukopenia and neutropenia occurred in 22 (61%) and 27 (75%) patients, respectively, but the mean duration of leukopenia (< 2,000/mm3) and neutropenia (< 1,000/mm3) was 3.4 and 3.5 days, respectively, and there was no instance of life-threatening infection. Thrombocytopenia and anemia of grade 3 or 4 occurred in 28% and 36% of our subjects, respectively. Grade 2 nausea and vomiting occurred in 47% of the patients. Elevated serum creatinine levels (> 1.5 mg/dl) were observed in 3 (8%) of the 36 patients. One patient died of acute renal failure induced by hemorrhage of a gastric ulcer. This regimen is effective in the treatment of NSCLC and further studies of this combination are warranted.


Blighted ovum: ultrasonic, histopathologic and hormonal considerations. Thirty women experiencing early pregnancy failure (blighted ovum) were studied at frequent intervals with serial measurements of serum human chorionic gonadotropin (beta-hCG), progesterone (P4) and estradiol (E2). The diagnosis of blighted ovum had previously been made by careful ultrasonic examination (s). Histopathologic findings in the placenta were studied in all cases. Hormonal levels were variable and in most of the cases indistinguishable from normal pregnancies. In only 50% of the cases the histopathologic examination revealed findings compatible for the blighted ovum criteria.


Amniotic fluid hormone profiles during normal and abnormal pregnancy. Amniotic fluid (AF) and maternal serum (MS) chorionic gonadotropin (HCG), placental lactogen (HPL), pregnancy-specific beta 1-glycoprotein (SP1), total estrogens (ET), alpha-fetoprotein (AFP) and prolactin (PRL) were measured by enzyme-immunoassays, in 50 normal (A) and in 37 abnormal (B) pregnancies, from 16th to 40th weeks. A: the proteins HCG, AFP and PRL showed a similar decreasing trend after the 20th week, while HPL and SP1 rose progressively throughout the 2nd trimester, thereafter remaining constant. On the contrary ET showed an increasing pattern until term. Chorionic gonadotropin HPL and SP1 in MS were higher than in AF, while AF values of AFP and PRL were higher than in MS, but the ratio MS/AF of all hormone values increased significantly from the 2nd to the 3rd trimester (p < 0.005-p < 0.000001). Estrogens had about the same concentration in AF and MS during the 2nd trimester, but at term of pregnancy, their AF values were double those of MS. B: in polyhydramnios, elevated AF placental hormones were found, while PRL was very low. In erythroblastosis and diabetes, AFP was very low, but placental hormones, PRL and ET were both high and low. In toxemia, SP1, hCG and PRL were elevated, while HPL and ET were very low. In anencephaly and hydrocephaly with spina bifida, AFP was markedly elevated and ET were very low, but in simple hydrocephalus, very low AFP was found. In chromosomal anomalies very high placental hormones and very low AFP and ET were found.(ABSTRACT TRUNCATED AT 250 WORDS)


An unusual T-cell surface phenotype in vivo correlates with the failure to proliferate and produce IL-2 in vitro in a patient with common variable immunodeficiency. Stimulation of T-lymphocytes derived from some patients with common variable immunodeficiency (CVID) syndrome results in defective proliferation. The underlying mechanism is related to the inability of stimulated cells to secrete IL-2 while the expression of IL-2 receptor (IL-2R) is normal. We have identified a patient whose peripheral T-cells failed to proliferate and secrete IL-2 upon stimulation. The addition of recombinant IL-2 restored proliferation. The defect did not seem to be caused by accessory cell failure since the patient's adherent cells produced IL-1 and IL-6, and addition of allogeneic irradiated cells did not induce proliferation. Stimulation of CVID T-cells with phorbol esters and Ca2+ ionophore induced both IL-2 secretion and proliferation, indicating the absence of a defect in the transcription and/or translation of the IL-2 gene. The patient's T-cells expressed high levels of CD3. The majority of T-cells expressed the CD38 molecule which is normally found on thymocytes or activated T-cells but not peripheral blood T-cells and HLA-DR, another activation marker. However, CD25 (the IL-2R) and CD1, a marker of more immature thymocytes, were not expressed. Finally, the patient's cells were sensitive to an in vitro corticosteroid treatment. The possibilities that this patient's T-cells represent anergic T-cells or not fully matured thymocytes are discussed.


Mapping of the immunoreactive domains of a small nuclear ribonucleoprotein-associated Sm-D autoantigen. The Sm-D(D1) small nuclear ribonucleoprotein (snRNP) polypeptide is a major target of autoantibodies diagnostic for systemic lupus erythematosus. The cDNA encoding the protein from Raji cells was expressed in Escherichia coli as a fusion protein with anthranilate synthase (TrpE-Sm-D). When tested by protein blot, the recombinant polypeptide was strongly immunoreactive under defined blotting conditions, which appear to facilitate the refolding of the polypeptide into a native conformation. Multiple translational fusions between the trpE gene and fragments encompassing the length of the Sm-D coding sequence were constructed for epitope mapping. The results describe two general patterns of anti-Sm reactivity: (i) antibodies that recognize only the full-length antigen and are presumably directed against discontinuous epitopes, and (ii) antibodies that recognize the carboxy terminus of the antigen which embodies an extended/charged structure.


Generalized inflammation during peritonitis evidenced by intracutaneous E-selectin expression. E-selectin is a human endothelial leukocyte adhesion molecule which is expressed on endothelial cells after exposure to inflammatory mediators and which is known to be involved in the adhesion of polymorphonuclear cells to the endothelium in vitro. Data on E-selectin expression in vivo are limited. In the present report, we studied the expression of E-selectin in skin biopsies from patients with peritonitis due to a perforation of the gastrointestinal tract. Substantial E-selectin expression was observed on the vasculature of the skin from six out of eight of these severely ill patients. Skin obtained from healthy individuals stained negative, or showed a faint patchy staining in 30% of biopsies tested. These results provide evidence that E-selectin expression was induced at a distance from the primary inflammatory process on the vascular endothelium of the skin during severe peritonitis. Cutaneous E-selectin expression thus reflected on the surface of the body a state of generalized activated endothelium.


Hydroxyethyl starch induced acquired von Willebrand's disease. Hydroxyethyl starch (HES) (Hespan, DuPont) is a widely used synthetic volume expander which in standard doses of up to 1.5l in 24 h has no significant effect on coagulation (Munsch et al. 1988). However, the data sheet states that in large volumes HES may alter the coagulation mechanism. We now report a case of HES induced acquired von Willebrand's disease (vWD) in which severe bleeding occurred.


Nucleotide sequence of the central coding region of bovine erythrotropin/insulin-like growth factor II cDNA from fetal intestine and northern analysis of the major IGF II transcripts at the time of hepatic erythropoiesis. 1. cDNA for insulin-like growth factor II (IGF II) was synthesized from poly A(+)-RNA from fetal bovine intestine and amplified. 2. The sequence corresponding to amino acids 6-62 was identical to a published ovine IGF II sequence cDNA with the exception of a single nucleotide change (G to A). 3. Northern blot analysis of intestine, liver, kidney and spleen from bovine fetuses showed multiple IGF II RNA species which are more similar to the human than to the rodent mRNAs. 4. Under the hybridization conditions used, synthesis of antisense strands, as described in embryonic chicken IGF II transcripts, was undetectable.


Immunochemical characterisation of tachykinin immunoreactivity in the nervous system of the garden snail, Helix aspersa. 1. Circumoesophageal ganglia and foot muscle of the garden snail, Helix aspersa, were subjected to immunocytochemistry using antisera to the tachykinins, substance P (SP), neurokinin A (NKA), kassinin (KAS) and eledoisin (ELE). 2. Immunoreactivity in neuronal somata and fibres was detected only with the SP antiserum. 3. SP and NKA radioimmunoassays were performed on extracts of circumoesophageal ganglia. In common with immunocytochemistry, immunoreactivity was only detected with the SP antiserum. 4. Gel permeation chromatography of extracts resolved a single peak of immunoreactivity eluting slightly later than synthetic mammalian SP. Reverse-phase HPLC of immunoreactive fractions resolved two immunoreactive peptides representing oxidised and reduced forms of a single peptide. 5. These data suggest that the nervous system of H. aspersa contains a single tachykinin with C-terminal structural characteristics similar to mammalian SP.


Time course of glutamate receptor expression in individual oocytes of Xenopus laevis after injection of rat brain RNA. 1. The receptor for the neurotransmitter glutamate was functionally expressed in oocytes of Xenopus laevis after microinjection of rat brain RNA. The functional differentiation of this receptor type was further analyzed. 2. The development of the sensitivity to the agonists showed a time course which was differential for the various ligands in individual oocytes. 3. Sensitivity appeared after one day for kainate (KA), after two days for alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionate (AMPA) and quisqualate (QA), and after five days for N-methyl-D-aspartate (NMDA). 4. The KA response was markedly reduced by simultaneous application of AMPA. This was even found on the first day when an agonistic AMPA reaction was not detectable. 5. NMDA and non-NMDA receptors can clearly be differentiated by their delay of expression.


Second messengers and ion channels in acetylcholine-induced chloride secretion in hen trachea. 1. Hen tracheal epithelium can be stimulated by serosal application of acetylcholine (ACh) to secrete Cl- equal to approximately 60-90 microA/cm2. 2. Radio-ligand-displacement for IP3, cAMP and cGMP and ion channel selective drugs in voltage clamp set-ups were employed to characterize second messengers and Cl-, K+ and Ca2+ channels involved in the ACh response. 3. ACh induced a significant rise in IP3 in isolated tracheocytes, while ACh did not influence the production of cAMP in whole tissue, isolated tracheocytes or basolateral cell membrane vesicles. Further ACh desensitization did not effect cAMP level in tracheocytes. In addition neither ACh stimulation nor desensitization interfered with cAMP production in presence of 4.5 microM forskolin in tracheocytes, a level of forskolin rising base level cAMP by around five fold. 4. Around 35% of ACh Cl- secretion depends on Ca2+ mobilization from internal stores and about 65% on Ca2+ influx over basolateral membrane. The activated Ca2+ channel is insensitive to class I, II, III and IV Ca2+ antagonists. 5. A 23187 can mimic the ACh effect although 30% is indomethacin-sensitive demonstrating a prostaglandin activated adenylyl cyclase. 6. Two K+ channels are involved in ACh secretion, one sensitive to Ba2+ and quinine and both insensitive to 4-aminopyridine, apamin, charybdotoxin and TEA. 7. Flufenamate and triaminopyrimidine block a non-selective ion channel likely involved in the ACh response. An ACh activated apical Cl- channel is NPPB-sensitive.


A short-term test for nucleotoxicity that uses chick embryo cells treated in vitro and in vivo--physico-chemical and biochemical investigations. 1. In vitro, some nucleotoxic or potentially nucleotoxic agents were tested with freshly isolated liver and brain cells from chick embryos as well as with thymic cells of the rat. 2. In vivo, chicken embryos were exposed to X-rays, methyl methanesulfonate, methyl nitrosourea, triethylene thiophosphoramide, and dimethylnitrosamine. 3. The toxic effects were determined by viscometry of alkaline cell lysates, nucleoid sedimentation, scheduled (SDS) and unscheduled (UDS) DNA synthesis and/or RNA synthesis. 4. The dose-effect curves obtained in vitro show that directly acting genotoxic agents are detected by the embryonic cells with equal or comparable sensitivity as by mammalian cells. 5. In vivo, genotoxicity is reflected by a decrease in alkaline lysate viscosity, nucleoid sedimentation and SDS and an increase in UDS. 6. From the present results it is suggested that chick embryo cells offer a simple, rapid and inexpensive short-term nucleotoxicity test for directly acting agents, the main disadvantage being the innate inability to biotransform indirectly acting agents.


Systemic contact dermatitis from subcutaneous hydromorphone. We report a patient who developed a generalized dermatitis after a period of progressive local intolerance to continuous subcutaneous infusion of hydromorphone for cancer pain. Sensitization to hydromorphone was proved by a positive patch test. Infusions with an equianalgesic dose of diacetylmorphine were well tolerated, without local or systemic side-effects, and prolonged the duration of infusion sites.


Growth factor-dependent phosphorylation of membrane proteins in cultured human retinal pigment epithelial cells. Recently, growth factors are known to phosphorylate tyrosine residues of proteins to regulate cellular functions. We investigated growth factor-dependent phosphorylation of membrane proteins in cultured human retinal pigment epithelial (RPE) cells. The phosphorylation experiments were done in membrane preparations of cultured RPE cell and the reaction was started by applying [32P]adenosine 5'-triphosphate (ATP) at 0 degrees C, and terminated after 0, 1, 5, 15, and 30 min. The samples were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and were analyzed by autoradiography. Many proteins showed time-dependent phosphorylation. Among them, a 170 kDa protein showed platelet-derived growth factor (PDGF)-specific phosphorylation with both time- (up to 30 min) and dose-(maximal effect at 50 ng/ml) dependence. On the other hand, epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) showed no specific phosphorylation. Phosphoaminoacids of the 170 kDa protein were analyzed by thin layer chromatography and autoradiography. Phosphotyrosine showed much higher radioactivity than phosphoserine or phosphothreonine. Consequently, PDGF induced phosphorylation of the 170 kDa protein which mainly consisted of phosphotyrosine. The data suggest that tyrosine phosphorylation of membrane protein is involved in signal transduction of PDGF in human RPE cells.


Increased expression of keratin polypeptides in long term culture of adult rat hepatocytes. Adult rat hepatocyte cultures showed the presence of albumin after 1 week of seeding. As the cultures aged, the cells commenced expressing alpha-foetoprotein and later keratin polypeptides 55 and 52 kD but ceased expressing albumin and alpha-foetoprotein. Enhanced expression of keratin polypeptides was confirmed by Western blot analysis in long term cultures. A possible mechanism for dedifferentiation of hepatocytes in culture is discussed.


Thrombus imaging in dogs with a monoclonal antibody (SZ-51) specific for activated human platelets. To specifically detect the localization of thrombus in vivo, we prepared a monoclonal antibody (McAb) SZ-51 specific for an alpha-granule membrane protein (GMP-140) on the surface of activated human platelets. The thrombus binding rate in vitro was 80 +/- 5% for 131I-SZ-51 and 4.4 +/- 0.5% for 131I-nonimmune IgG. Owing to the crossreaction of McAb SZ-51 with the activated platelets of dogs, thrombus in the femoral artery and vein of dogs was formed and imaged with single photon emission computerized tomography (SPECT). The ratio of thrombus to blood radioactivity (T/B) was 2.1, 4.8, 14.0 and 18.0 at 1, 2, 3 and 4 hours after injection of 131I-SZ-51 (0.6 mCi, 50 micrograms) into the arterial thrombus respectively, while the T/B ratio was 1.7, 2.2, 5.3 and 8.0 for venous one. The injection of 131I-nonimmune IgG at the same doses yielded a T/B ratio of 1.2 +/- 0.3 at each time period for both arterial and venous thrombi. These findings were in good agreement with the counting of removed thrombi 24 hours after the injection of radiotracer. The ratio was 21.7 and 2.6 for the 131I-SZ-51 in the arterial and venous thrombus, respectively. However, there were only 1.48 and 1.6 for the 131I-nonimmune IgG. These results indicate the great potentiality of McAb SZ-51 in application to detection of thrombi in vivo.


Photo-bleaching and photon saturation in flow cytometry. In flow cytometry, small particles travel at a high speed through a bright light spot. The high light intensity at the point of measurement causes measurable photon saturation. This observation indicates that the rate at which individual dye molecules emit photons is close to the maximum emission rate. Despite the short exposure time, individual molecules may go through a few hundred excitation cycles while they are in the light beam. The absorbed light dose causes significant dye destruction. This article presents experimental procedures to determine the extent of photon saturation and photo-bleaching of dyes bound to cell nuclei in a flow cytometer. Measurements of Hoechst and propidium iodide bound to chromatin show that the amount of dye bleached per emitted photon is the same at low and high illumination intensities. This finding indicates that photon emission and dye destruction are both the result of the absorption of single excitation photons. The experimental observations allow rough estimates of the lifetime of the excited state and the lifetime of the molecule. The lifetime of the Hoechst 33258 bound to DNA is estimated to be 100 excitation-relaxation cycles. The average propidium iodide molecule lasts approximately 200 excitation-relaxation cycles. The theoretical considerations show that the optimal illumination conditions are different for bleaching and nonbleaching dyes. An optical arrangement for high precision measurements of bleaching dyes is presented.


Cell cycle analysis of asynchronous cell populations by flow cytometry using bromodeoxyuridine label and Hoechst-propidium iodide stain. Continuous labelling of cells with deoxybromouridine (BrdUrd) followed by staining with a bis-benzimidazole (Hoechst 33258) and a phenanthridinium (propidium iodide or ethidium bromide) allows the cells to be separated by flow cytometry according to the extent of their DNA replication. This BrdUrd-Hoechst/PI method has been used mainly to observe perturbations of the cell cycle in synchronously growing cells. In this paper we demonstrate that, when the method is applied to asynchronously dividing cells, more extensive information can be derived about the effects of cytotoxic and other treatments on the kinetics of the cell cycle. The interpretation of the data is explained, the effects of different types of cytotoxic agent are described, and the method is compared briefly to other methods for following cell cycle kinetics.


Streptavidin-based quantitative staining of intracellular antigens for flow cytometric analysis. A streptavidin-biotin-based three-step immunolabeling protocol for quantitative staining of intracellular antigens for flow cytometric analysis was evaluated using simian virus 40 (SV40) large T antigen. The concentration as well as the quantity of antibody used required optimization. The optimum labeling conditions varied moderately with cell lines that express T antigen levels over a 40-50-fold range. The procedure resulted in specific fluorescence 2.4 times higher than that using a comparable two-step indirect immunofluorescence technique. The gain in resolution was shown to be greater when staining cells with lower antigen levels. In the analysis of background fluorescence, the principal components were, as for the two-step technique, autofluorescence and propidium spectral overlap. While streptavidin does add to the background, the increase is relatively small. Decreasing the propidium concentration from 50 micrograms/ml to 5 micrograms/ml was found to reduce significantly the level of background from this source. Theoretical aspects of quantitative staining and of resolution versus quantification are discussed.


Improved BrdUrd-Hoechst bivariate cell kinetic analysis by helium-cadmium single laser excitation. In laser based flow cytometers, UV excitation of Hoechst 33258 and propidium iodide (PI) or ethidium bromide (EB) is performed with 351/364 nm high power lines of UV-capable argon ion lasers, which are expensive and short-lived. In this paper we note for the first time that helium-cadmium lasers emitting 10 to 30 mW at 325 nm are even more superior for cell kinetic bivariate bromodeoxyuridine (BrdUrd)/Hoechst PI or EB cell cycle analysis. HeCd single laser UV excitation gives comparable CVs for cell cycle distributions, and almost normal G2M/G1 ratios of 1.9 to 2.0 for all cell cycles. This is shown for synchronous and asynchronous cell populations on a FACStar+ and an Ortho Cytofluorograf. Therefore we recommend helium-cadmium lasers as low-power, cheap, and long-lived UV excitation sources for the cytochemically simple but high resolution multiparameter BrdUrd-Hoechst cell kinetic analysis.


Perturbation of developmental gene expression in rat liver by fibric acid derivatives: lipoprotein lipase and alpha-fetoprotein as models. Liver lipoprotein lipase (LPL) and alpha-fetoprotein (AFP) gene expression show similar developmental patterns. Both mRNAs are abundantly expressed in neonatal rat liver and gradually disappear upon ageing. Treatment with fibric acid derivatives, such as fenofibrate, not only delays the developmental extinction of the LPL gene, but also increases LPL mRNA levels in neonatal rat liver. Similarly, the developmental extinction of the AFP gene in the liver is clearly delayed after fenofibrate. In adult rat liver, fibric acid derivatives transcriptionally reinduce a mRNA with similar size as LPL, but no effect on AFP mRNA was detected. Sequence comparison of clones isolated from a fenofibrate-induced cDNA library demonstrates that the fenofibrate-(re)induced mRNA in adult rat liver is encoding for LPL. The induction of LPL after fenofibrate is tissue-specific, since heart and adipose tissue LPL mRNA levels remain unchanged. In conclusion, fibric acid derivatives modulate developmental expression patterns in rat liver, and may selectively reinduce the expression of extinct genes in adult rat liver.


TRP-2/DT, a new early melanoblast marker, shows that steel growth factor (c-kit ligand) is a survival factor. We have used a probe derived from TRP-2/DT to detect migratory melanoblasts shortly after they emerge from the neural crest, as early as 10 days post coitum (dpc). TRP-2/DT expression is otherwise restricted to the presumptive pigmented retinal epithelium, the developing telencephalon and the endolymphatic duct. The pattern of steel and c-kit hybridisation in the developing brain differed from that of TRP-2. TRP-1 and tyrosinase probes also detected melanoblasts but were both expressed later in development than TRP-2. We used the TRP-2/DT probe to investigate the way that the Steel-dickie (Sld) mutation interferes with melanocyte development, and found that the membrane-bound steel growth factor which is missing in Sld/Sld mutants is necessary for the survival of melanoblasts but not for their early migration and initial differentiation.


Developmentally regulated cell surface expression and function of c-kit receptor during lymphocyte ontogeny in the embryo and adult mice. We have used a c-kit-specific monoclonal antibody, immuno-fluorescence staining and flow fluorocytometry or microscopy analysis to assess the cell surface expression of the c-kit receptor on a panel of non-transformed clones representing different stages of T- and B-lymphocyte development, freshly isolated lymphoid cells from thymus, bone marrow and spleen of young adult C57BL/6 mice and cells from yolk sac, thymus and liver of developing C57BL/6 mouse embryos. Pro-T, Pro-B and Pre-B clones derived from thymus or liver of 14-day embryos are c-kit+. Starting at day 8 to 8.5 in yolk sac, day-10 in fetal liver, and day 11 to 12 in fetal thymus, there are many c-kit+ cells. The number of c-kit+ cells in liver and thymus increases up to day 15 and progressively decreases thereafter. Cell sorter purified c-kit+ day 14 fetal liver cells fully reconstitute the T and B cell compartments of immunodeficient Scid mice. Stromal cells or epithelial cells derived from fetal thymus or liver, which can support growth and differentiation of c-kit+ lymphocyte progenitor clones, synthesize mRNA for Steel Factor (SF), the ligand of c-kit. In the adult mouse, however, c-kit expression is restricted to very early stages of T- and B-lymphocyte development (multipotent progenitors, B-cell/myelocytic progenitors, Pro-T and Pro-B lymphocyte progenitors). Most cells at the Pre-T, Pre-B and later stages of development do not bear detectable c-kit. Using Cos-1 cells transfected with mouse SF-cDNA and an antagonistic c-kit receptor-specific antibody, we show that the c-kit/SF system contributes to the survival of lymphocyte progenitors and enhances the proliferative responses of these cells to other growth factors (i.e. IL2, IL3, IL4, IL7). However, the c-kit receptor/SF ligand pair is neither sufficient nor necessary for the differentiation of lymphocyte progenitors into mature T- or B-lymphocytes. Finally, in stromal cell lines from fetal liver and adult bone marrow and thymic epithelial cell lines the level of steady state SF-RNA transcripts is inversely correlated with that of IL-7-mRNA. Moreover, IL7 inhibits the synthesis of SF-mRNA in stromal cells and rIL6 abrogates this inhibitory effect of rIL7. Thus, the expression of SF in stromal cells is subjected to complex regulation by other cytokines produced by the same stromal cells or by neighboring cells in a given microenvironment.(ABSTRACT TRUNCATED AT 400 WORDS)


Molecular organization and embryonic expression of the hedgehog gene involved in cell-cell communication in segmental patterning of Drosophila. hedgehog is a segment polarity gene necessary to maintain the proper organization of each segment of the Drosophila embryo. We have identified the physical location of a number of rearrangement breakpoints associated with hedgehog mutations. The corresponding hh RNA is expressed in a series of segmental stripes starting at cellular blastoderm in the posterior portion of each segment. This RNA is localized predominantly within nuclei until stage 10, when the localization becomes primarily cytoplasmic. Expression of hh RNA in the posterior compartment is independent of most other segment polarity genes, including en, until the late extended germ-band stage (stage 11). Sequence analysis of the hedgehog locus suggests the protein product is a transmembrane protein, which may, therefore, be directly involved in cell-cell communication.


Prediction of response to drug therapy of cancer. A review of in vitro assays. Cancer chemotherapy has witnessed a great deal of progress since the introduction of the nitrogen mustards in the 1940s. Unfortunately, individual patients with apparently identical tumour histologies do not always respond identically to the same drug regimen. Determining the sensitivity and resistance of an organism before treatment has been the standard of care in infectious diseases for many years, while in oncology treatment has been initiated according to tumour histology rather than the tumour's sensitivity to a given agent. Attempts to individualise therapy have been the goal of oncologists since the 1950s. Since that time a number of in vitro assays have been developed to predict therapeutic outcome prior to the start of therapy. In the 1970s, with the introduction of the human tumour stem cell assay, it was generally believed that oncology was on the threshold of entering an era of predictive in vitro chemosensitivity testing. Unfortunately, this assay was shown to have a number of technical drawbacks including the low plating efficiencies of many primary tumour samples which thus limits the percentage which can be evaluated, leaving us still at this threshold today. Several recent developments, such as the Kern assay, which measures inhibition of radioactive precursors into tumour cells in the presence of antineoplastic agents, ATP bioluminescence assays, and the fluorescent cytoprint assay offer the promise of rapid and sensitive results. Other assays, such as the tetrazolium-based MTT and the sulphorhodamine blue assay appear to hold more promise in the screening and evaluation of potential new agents in established tumour cell lines than for evaluating chemosensitivity of clinical specimens. However, before a particular assay can be considered as an in vitro test of chemosensitivity or resistance, controlled prospective studies must be carried out to validate the assay in a number of different tumour types.


Histamine H2-receptor antagonists in peptic ulcer disease. Efficacy in healing peptic ulcers. Duodenal ulcer healing depends on the degree and length of inhibition of gastric secretion and upon the duration of therapy, while gastric ulcer healing is dependent mainly on the duration of therapy. Currently marketed doses of the histamine H2-receptor antagonists heal between 77 and 92% of duodenal ulcers at 4 weeks, and adjuvant treatment to eradicate Helicobacter pylori increases this rate. Once-daily administration is as effective as more frequent dosing regimens and may even result in higher healing rates. Gastric ulcers heal more slowly, but 75 to 88% of ulcers heal after 8 weeks of treatment. While newer more potent acid suppressors such as omeprazole heal ulcers slightly more quickly, the H2-receptor antagonists have an unparalleled safety record of over 15 years. It is unlikely that the prostaglandin analogues can improve on the efficacy of the H2-receptor antagonists with as low an incidence of side effects.


Use of plasma volume expanders in myocardial revascularisation. The optimal solution for priming cardiopulmonary bypass machines and for postoperative resuscitation following myocardial revascularisation should be inexpensive, free of risk of transmitting disease, and free of other detrimental side effects. Colloid solutions are preferred over crystalloid solutions because of elevations in extracellular sodium and water that occur with cardiopulmonary bypass. Albumin, plasma protein solution, hetastarch (hydroxyethyl starch) and dextran are available for use if blood is not necessary and mediastinal blood is not available. Hetastarch is associated with a lower risk of bleeding and less risk of allergic reaction than dextran, and its cost is substantially less than that of albumin. However, high doses increase the risk of bleeding complications.


Sinus node disease. Current concepts in diagnosis and therapy. Sinus node disease (SND) encompasses a number of abnormalities of sinus impulse generation and transmission within the atria and may lead to both bradyarrhythmias and tachycardias. Such abnormalities may be due to primary atrial electrophysiological abnormalities, or be secondary to drugs or abnormal autonomic control. The diagnosis may be readily established from the surface ECG or Holter recordings in many cases, but invasive electrophysiological study or assessment of the effects of autonomic blockade may be required in symptomatic patients in whom the diagnosis is suspected but not confirmed by simple electrocardiographic monitoring. Treatment should be restricted to those patients in whom clear correlation between symptoms and electrocardiographic or electrophysiological abnormalities has been established. Although a number of pharmacological agents have been assessed, the treatment of bradyarrhythmias should be permanent pacing. There is now substantial evidence that physiological (atrial or dual chamber) pacing reduces atrial arrhythmias, systemic embolisation, progression to heart failure and mortality, compared to single chamber ventricular pacing. Antiarrhythmic therapy may be required to control atrial tachyarrhythmias if they persist following pacing. In patients with uncontrolled atrial arrhythmias, especially those with ventricular pacemakers, long term oral anticoagulation should be considered to reduce the risk of systemic embolisation which is a common complication in patients with the bradycardia/tachycardia syndrome.


Heparin therapy. Regimens and treatment considerations. Heparin is a parenteral antithrombotic agent with efficacy in the treatment and prevention of venous thromboembolic disease and in preinfarctional angina. Accumulating evidence also suggests that heparin is useful in the prevention of coronary artery reocclusion after thrombolytic therapy for acute myocardial infarction, and in the prevention of left ventricular mural thrombosis after anterior wall myocardial infarction. Heparin appears to offer only marginal benefit in reducing mortality when given in combination with thrombolytic therapy and aspirin for acute myocardial infarction. When used for prevention of venous thromboembolism in moderate risk patients, heparin should be given subcutaneously in a dose of 5000 U every 12 hours for 5 to 7 days or until the patient is ambulatory. In higher risk patients, such as those undergoing total hip replacement, heparin should be given subcutaneously every 12 hours in a dose to prolong the activated partial thromboplastin time (aPTT) by 4 to 5 seconds into the upper normal range. When used to treat active venous thromboembolism or the peri-infarctional state, heparin should be given by intravenous infusion with loading and maintenance doses to consistently prolong the aPTT to between 1.5- and 2.5-fold the control value (mean of laboratory's normal range). If constant intravenous infusion is not possible, the drug should be given subcutaneously every 12 hours to consistently prolong the aPTT between 1.5 and 2.5 times control. This regimen is also recommended in pregnant women with venous thromboembolic disease or mechanical heart valves.


Azithromycin. A review of its antimicrobial activity, pharmacokinetic properties and clinical efficacy. Azithromycin is an acid stable orally administered macrolide antimicrobial drug, structurally related to erythromycin, with a similar spectrum of antimicrobial activity. Azithromycin is marginally less active than erythromycin in vitro against Gram-positive organisms, although this is of doubtful clinical significance as susceptibility concentrations fall within the range of achievable tissue azithromycin concentrations. In contrast, azithromycin appears to be more active than erythromycin against many Gram-negative pathogens and several other pathogens, notably Haemophilus influenzae, H. parainfluenzae, Moraxella catarrhalis, Neisseria gonorrhoeae, Urea-plasma urealyticum and Borrelia burgdorferi. Like erythromycin and other macrolides, the activity of azithromycin is unaffected by the production of beta-lactamase. However, erythromycin-resistant organisms are also resistant to azithromycin. Following oral administration, serum concentrations of azithromycin are lower than those of erythromycin, but this reflects the rapid and extensive movement of the drug from the circulation into intracellular compartments resulting in tissue concentrations exceeding those commonly seen with erythromycin. Azithromycin is subsequently slowly released, reflecting its long terminal phase elimination half-life relative to that of erythromycin. These factors allow for a single dose or single daily dose regimen in most infections, with the potential for increased compliance among outpatients where a more frequent antimicrobial regimen might traditionally be indicated. The potential disadvantage of low azithromycin serum concentrations, however, is that breakthrough bacteraemia may occur in patients who are severely ill; nevertheless, animal studies suggest that tissue concentrations of azithromycin are more important than those in serum when treating respiratory and other infections. The clinical efficacy of azithromycin has been confirmed in the treatment of infections of the lower and upper respiratory tracts (the latter including paediatric patients), skin and soft tissues (again including paediatric patients), in uncomplicated urethritis/cervicitis associated with N. gonorrhoeae, Chlamydia trachomatis or U. urealyticum and in the treatment of early Lyme disease. Azithromycin was as effective as erythromycin and other commonly used drugs including clarithromycin, beta-lactams (penicillins and cephalosporins), and quinolone and tetracycline antibiotics in some of the above infections. Some patients with acute exacerbations of chronic bronchitis due to H. influenzae may be refractory to therapy with azithromycin (as is the case with erythromycin) indicating the need for physician vigilance, although it should be noted that azithromycin is of equivalent efficacy to amoxicillin in the treatment of such patients. In the therapy of urethritis/cervicitis associated with C. trachomatis, N. gonorrhoea or U. urealyticum, a single dose azithromycin regimen offers a distinct advantage over currently available pharmacological options, while providing effective therapy.(ABSTRACT TRUNCATED AT 400 WORDS)


Cefodizime. A review of its antibacterial activity, pharmacokinetic properties and therapeutic use. Cefodizime is a third generation cephalosporin with a broad spectrum of antibacterial activity. Administered intravenously or intramuscularly, cefodizime 1 to 4 g daily for an average of 7 to 10 days produced clinical cure in 80 to 100% of patients (adults, elderly or children) with upper or lower respiratory tract infections or urinary tract infections, and in comparative trials cefodizime was as effective as other third generation cephalosporins. A single dose of cefodizime 1 or 2 g is also useful in treating lower urinary tract infections, particularly uncomplicated infections, with a rate of clinical success of 72 to 88%. Urogenital gonorrhoea, whether caused by beta-lactamase producing or non-beta-lactamase producing Neisseria gonorrhoeae, is very effectively treated by single dose therapy with intramuscular cefodizime 0.25 to 1 g (virtually 100% cured). Preliminary data from a small number of patients indicate that cefodizime may also be useful in the treatment of otitis media, sinusitis and gynaecological infections, and for the prophylaxis or treatment of surgical infections. The clinical efficacy of cefodizime in comparison with other third generation cephalosporins is superior to that predicted from in vitro results. This superior activity of cefodizime may be related to the relatively long elimination half-life of the drug or its ability to modify some functions of the immune system--a potentially important finding awaiting further investigation. Cefodizime is well tolerated and has a tolerability profile similar to other members of its class with systemic adverse events being primarily gastrointestinal or dermatological. Thus, limited comparative studies indicate cefodizime has the potential to become a useful alternative to current antimicrobial therapy for the treatment of a variety of infections. Cefodizime may be more convenient to administer than some other agents of its class as it may be given once or twice daily. While there are no trials comparing cefodizime to other third generation cephalosporins in immunosuppressed populations, preliminary information indicates cefodizime may be useful in this group.


Bepridil. A review of its pharmacological properties and therapeutic use in stable angina pectoris. Bepridil is a calcium antagonist with direct negative chronotropic, dromotropic, inotropic and vasodilatory actions which reduces myocardial oxygen consumption and increases coronary blood flow, leading to a significant anti-ischaemic and antianginal effect in the absence of reflex tachycardia. In contrast to other calcium channel blockers, bepridil produces only modest peripheral vasodilatation and displays weak antihypertensive activity. Its plasma elimination half-life of 1 to 2 days permits once daily administration. Results of short term clinical trials have shown bepridil to be of comparable efficacy to nifedipine, verapamil, diltiazem, propranolol and nadolol in decreasing the frequency of anginal attacks and consumption of nitroglycerin (glyceryl trinitrate) in patients with stable angina. Bepridil is more effective than nifedipine in improving exercise performance in patients with stable angina. Although bepridil proved superior to diltiazem in improving exercise performance in patients refractory to diltiazem, further studies are required to confirm the efficacy of bepridil in patients refractory to, or intolerant of, other antianginal agents. Bepridil in therapeutic doses is well tolerated, and appears to have a similar adverse effect profile to the established calcium antagonists. However, rate-dependent prolongation of the QTc interval and development of torsade de pointes have been associated with the use of bepridil. Therefore, bepridil is contraindicated in patients with hypokalaemia, those receiving other drugs that may prolong the QT interval, and those with congenital QT interval prolongation. Future clinical research will help to further define the position of bepridil as an antianginal treatment relative to the traditional calcium antagonists; in the interim, bepridil is indicated for the treatment of patients with angina refractory to or intolerant of other agents.


Nadroparin calcium. A review of its pharmacology and clinical applications in the prevention and treatment of thromboembolic disorders. Nadroparin calcium is a low molecular weight heparin with a mean molecular weight of 4.5 kD. Compared with unfractionated heparin, nadroparin calcium has a greater ratio of anti-factor Xa/anti-factor IIa activity. Nadroparin calcium has a longer half-life and greater bioavailability than unfractionated heparin and can be administered by subcutaneous injection once daily for prophylaxis and twice daily for treatment. In clinical trials, nadroparin calcium has been shown to be at least as effective as unfractionated heparin in preventing deep venous thrombosis (DVT) after various surgical procedures including major orthopaedic and abdominal surgery, and in maintaining the patency of the extracorporeal circulation in adults and children undergoing haemodialysis. Nadroparin calcium is well tolerated, the most common adverse event associated with its use being the development of minor haematoma at the operative incision site. In postmarketing surveillance data to date, the incidence of major haemorrhage related to nadroparin calcium use has been very low (< 1%). Nadroparin calcium has also been associated with a very low incidence of thrombocytopenia (< 0.001%). Thus, nadroparin calcium is an effective alternative to unfractionated heparin in the prophylaxis or treatment of thromboembolic venous events, with the advantages of more convenient administration and a lower incidence of thrombocytopenia.


Cefpodoxime proxetil. A review of its antibacterial activity, pharmacokinetic properties and therapeutic potential. Cefpodoxime proxetil is an orally administered prodrug which is absorbed and de-esterified by the intestinal mucosa to release the third generation cephalosporin, cefpodoxime. Cefpodoxime is stable towards the most commonly found plasmid-mediated beta-lactamases and the drug has a broad spectrum of antibacterial activity encompassing both Gram-negative and Gram-positive bacteria, rendering it a possible option for empirical use in a wide range of community acquired infections in both adult and paediatric patients. The extended plasma half-life of cefpodoxime (1.9 to 3.7 h) permits twice daily administration. In comparative trials, twice daily cefpodoxime proxetil (dose equivalent cefpodoxime 100 to 400 mg) was as effective as a 3- to 4-times daily regimen of phenoxymethylpenicillin in pharyngotonsillitis, as well as thrice daily amoxicillin (with or without clavulanic acid) or cefaclor against infections of the ear, the upper and lower respiratory tract, the urinary tract and those of the skin and soft tissues. The latter reflects the enhanced antistaphylococcal activity of cefpodoxime, which distinguishes it from other orally active third generation cephalosporins such as cefixime. Most notably, an oral regimen of cefpodoxime proxetil was as efficacious as parenterally administered ceftriaxone for the treatment of bronchopneumonia in hospitalised patients at risk due to the presence of underlying diseases, addictions or advancing age. A single oral dose of cefpodoxime was also as efficacious as ceftriaxone in uncomplicated anogenital gonococcal infections. Cefpodoxime proxetil is generally well tolerated, with mild to moderate gastrointestinal disturbances occurring in 4 to 15% of patients treated with therapeutic doses. Thus, a convenient twice daily oral regimen of cefpodoxime proxetil can be prescribed as an effective alternative to established beta-lactam therapies in the empirical outpatient treatment of infections of the respiratory and urinary tracts as well as those of the skin and soft tissues.


Pathophysiology of diabetes. A review of selected recent developments and their impact on treatment. Recent developments in epidemiology, physiology, anatomy and molecular biology have greatly increased our knowledge of the aetiology and immunological mechanisms involved in diabetes mellitus. This understanding has, in turn, facilitated progress in the diagnosis and treatment of the disease. It is generally accepted that both genetic and environmental factors have a role in the pathogenesis of insulin- and non-insulin-dependent diabetes mellitus. The contribution of insulin resistance or decreased insulin secretion to the pathogenesis of non-insulin-dependent diabetes remains controversial but it is likely that both have a role to play. Counterregulatory hormones, principally adrenaline (epinephrine) and glucagon, prevent blood glucose levels falling to extreme levels by antagonising the effect of insulin hypoglycaemia, and inducing hepatic glucose production. Patients with insulin-dependent diabetes frequently exhibit impaired glucose counterregulation and, although its aetiology is uncertain in some patients, intensification of insulin therapy per se has been implicated. Secondary failure of oral hypoglycaemic agents in patients with non-insulin-dependent diabetes is a major and often inevitable problem, necessitating combined use of sulphonylurea and insulin in most patients. Recently, new treatments for patients with diabetes have been developed, including insulin analogues administered by a variety of novel methods, pancreatic grafts and transplantation of islet cells. Although promising, the clinical viability of these techniques remains to be demonstrated.


Nutritional recommendations for diabetic patients and treatment with alpha-glucosidase inhibitors. Adjunctive treatment with acarbose (possibLy together with sulphonylurea or insulin treatment) can be effectively utilised to achieve blood glucose control if postprandial hyperglycaemia is a problem and cannot be sufficiently controlled by dietary modifications. The alpha-glucosidase inhibitor, acarbose, should be taken with meals that are rich in complex carbohydrates and low in simple sugars, as recommended by diabetes associations, to achieve the greatest possible benefit from treatment.


Oral antidiabetic agents. The emergence of alpha-glucosidase inhibitors. Hyperglycaemia in patients with non-insulin-dependent diabetes mellitus (NIDDM) results from impaired insulin action and/or deficient insulin secretion. These abnormalities lead to increased hepatic glucose production, the primary cause of fasting hyperglycaemia, and decreased peripheral glucose uptake, the major mechanism responsible for postprandial hyperglycaemia. Hyperglycaemia in patients with NIDDM can be decreased by several different mechanisms: (1) a decrease in nutrient ingestion; (2) an increase in insulin secretion; (3) a decrease in hepatic glucose production; (4) an increase in peripheral glucose uptake. Oral agents used to treat NIDDM operate through 1 or more of the above mechanisms. alpha-Glucosidase inhibitors, a new class of drugs that delay carbohydrate digestion and absorption, reduce postprandial glycaemic rises by about 3 mmol/L. Metformin decreases fasting and postprandial hyperglycaemia through increasing glucose uptake and perhaps decreasing appetite. Sulphonylureas lower hyperglycaemia by increasing insulin secretion and to a lesser degree potentiating insulin action on the liver and peripheral tissues. alpha-Glucosidase inhibitors are particularly useful as primary therapy for patients with mild to moderate hyperglycaemia and in those patients who may be at risk for hypoglycaemia or lactic acidosis. Sulphonylureas are indicated for the more severely hyperglycaemic NIDDM patients who are not yet candidates for insulin therapy. Metformin is useful in obese moderately hyperglycaemic NIDDM patients. These oral agents can be used in combination to give better glycaemic control than is possible with each alone.


Management of non-insulin-dependent diabetes mellitus. The initial management of non-insulin-dependent diabetes mellitus (NIDDM) should include patient education, dietary counselling and, when feasible, individualised physical activity. It is only when such measures fail that drug therapy should be considered. Dietary management of NIDDM includes a restriction in calories, and these should be appropriately distributed as carbohydrates, lipids and proteins. Supplementation of the diet with soluble fibre and supplementation with magnesium salts if hypomagnesaemia is demonstrated, is recommended. However, supplementation with fish oils or with fish oil-derived omega-3 fatty acids is not currently recommended. Oral drug therapies used in NIDDM include sulphonylurea derivatives, which are a first-line treatment in patients who are not grossly obese, metformin, which is the treatment of choice for obese patients, and alpha-glucosidase inhibitors such as acarbose, which are used mainly to reduce postprandial blood glucose peaks. These types of drugs can be used alone or in combination. Insulin therapy may be required to achieve adequate control of blood glucose levels in some patients. In several instances, it is suggested that insulin therapy be combined with sulphonylureas (essentially when residual insulin secretion is present), with metformin, or with alpha-glucosidase inhibitors. The treatment of disorders associated with NIDDM, such as obesity, hypertension or hyperlipidaemia, requires particular attention in diabetic patients, since some drugs can adversely affect glycaemic control. Oral drugs for the treatment of NIDDM include sulphonylurea derivatives used in first-line treatment in patients who are not grossly obese, metformin, which is often the treatment of choice for obese patients and, more recently, the alpha-glucosidase inhibitors, such as acarbose, which are effective in reducing the postprandial rise in blood glucose.


Management of insulin-dependent diabetes mellitus. Insulin therapy has been lifesaving for patients with insulin-dependent diabetes mellitus. Unfortunately, longer lifespan has unmasked microvascular, neurological and macrovascular complications that result in profound morbidity and increased mortality. Driven by the conviction that better physiological control of glycaemic levels will prevent and/or ameliorate long term complications, and by the desire to make diabetes care as user-friendly as possible, clinical research efforts have led to the development of new treatment methods with the aim of achieving near normal metabolic control. Such methods include the use of self monitoring, multiple daily insulin injection regimens, external and implantable insulin pumps, and whole organ pancreas and isolated islet cell transplantation. In addition, dietary manipulation, including the use of alpha-glucosidase inhibitors, has played a role in controlling glycaemia.


Safety profile of acarbose, an alpha-glucosidase inhibitor. Acarbose, an alpha-glucosidase inhibitor, delays absorption of carbohydrate in the gut, thereby lowering postprandial glucose levels. Safety data on this drug have been gathered in a series of studies on animals and in extensive clinical trials in humans. Although an initial long term feeding study in rats showed an excess of renal tumours at very high dosages of acarbose (up to 300 mg/kg bodyweight daily), further evaluation with similar studies in rats, hamsters, and dogs indicated that the problem was related to carbohydrate malabsorption. With adequate glucose intake and in gavage studies, no difference in tumour incidence between placebo- and acarbose-treated groups was seen. From 1976 to 1989, safety data on acarbose were obtained in approximately 8800 patients in 2 separate groups of clinical trials, the Bayer International Clinical Data Pool and the American phase III trials. Almost all adverse experiences, as reported by 56 to 76% of patients on acarbose vs 32 to 37% of patients on placebo, were related to the digestive system and included diarrhoea, flatulence, bloating and nausea. Most symptoms were of mild to moderate intensity and tended to improve with time. In the American trials a small but significant increase in liver transaminases was seen, 3.8% in acarbose-treated patients vs 0.9% in controls together with a 1% increase in anaemia in the acarbose group. Overall, acarbose was well tolerated and the adverse experience profile was clinically acceptable.


Preventing long term complications. Implications for combination therapy with acarbose. Long term complications continue to be the major source of morbidity and mortality in patients with diabetes. Acarbose could potentially help to reduce diabetic complications if it improved glucose control, reduced lipid levels and hyperinsulinaemia. Acarbose has been shown to effectively reduce postprandial hyperglycaemia and haemoglobin A1c. This effect might be helpful in patients with insulin-dependent diabetes mellitus, as insulin injections do not provide complete control of rises in postprandial glucose levels, and in patients with non-insulin-dependent diabetes mellitus, because it simplifies the treatment programme. If improved control is shown to reduce complications, acarbose may be helpful. Although acarbose does not reduce hyperinsulinaemia, it reduces lipid levels and thus could reduce the risk of atherosclerosis.


Effect of ambient oxygen concentration upon the acute toxicity of chlorophenols and heavy metals to the groundwater copepod Parastenocaris germanica (Crustacea). Acute static toxicity experiments have been performed under normoxic and hypoxic conditions. The test animals used were adults of the groundwater-adapted copepod Parastenocaris germanica. The animals originated from a sandy, gravelly phreatic aquifer of the Meuse valley in The Netherlands. Toxicants applied were pentachlorophenol, 3,4-dichlorophenol, zinc, and cadmium. The results were statistically evaluated by a log-logistic model. LC50 and LC5 values with 95% confidence limits were calculated. Response models of application under both oxygen conditions were compared. The influence of ambient oxygen concentration on sensitivity appeared to be very small; only in the case of pentachlorophenol were hypoxic and normoxic models slightly but significantly different. Comparisons with the sensitivity of other organisms are made and the results are discussed against the specific physiological adaptations of the organisms to groundwater conditions.


Induction and characterization of cytochromes P450IA and -IIB in the newt, Pleurodeles waltl. The newt (Pleurodeles waltl) is an amphibian species used in a mutagenicity test (micronucleus). This study was carried out to establish if the inducibility of hepatic cytochromes P450 of this species is similar to that of the rat. Our results showed that the newt is characterized by a lower level of hepatic cytochrome P450-dependent activities than the rat. Variations of enzymatic activities according to sex and season were observed. Specific activities in newt were characterized by an almost complete insensitivity to induction by phenobarbital pretreatment. On the other hand, pretreatment by 3-methylcholanthrene resulted in an increase in the metabolism of several hydroxycoumarin and resorufin derivatives, similar to the effects observed in rat liver. Occurrence of specific forms of cytochromes P450 was assessed by specific antibodies.


Toxic effects of omega chrome red ME and its treatment by adsorption. Toxic effects of Omega Chrome Red ME, a popular textile dye, on the nitrogen fixing cyanobacterium Nostoc calcicola were studied. The growth of N. calcicola was found to be suppressed at 10 and 20 mg liter-1 initial concentrations of dye, whereas a low initial concentration of 5 mg liter-1 slightly favors growth. Removal of the dye was carried out by adsorption using some cheap and unconventional adsorbents like coal, fly ash, wollastonite, and china clay. It has been observed that, in all cases, the low adsorbate concentration, the low temperature, and an acidic medium favor the dye removal process. The process of uptake follows first-order adsorption rate expression and obeys Langmuir's model of adsorption. The removal process is also partially diffusion controlled. Thermodynamic and pH studies were run to explain the results.


The effect of Cu (II) on the electro-olfactogram (EOG) of the Atlantic salmon (Salmo salar L) in artificial freshwater of varying inorganic carbon concentrations. The effect of inorganic copper species was studied by recording the receptor potential, electro-olfactogram (EOG), from the olfactory epithelium of Atlantic salmon (Salmo salar L). In a series of experiments, the olfactory organ was irrigated with aqueous copper solutions with concentrations of the free cupric ion (Cu2+) ranging from 0.2 to 9.7 microM. The diverse copper species were created by varying the amount of bicarbonate (NaHCO3) in artificial freshwater solutions of equal total copper concentrations. In general, these copper solutions induced a slow depolarization of the baseline followed by a hyperpolarization. The amplitudes of these variations in baseline potentials increased with increasing concentrations of Cu2+ ion, i.e., decreasing concentrations of NaHCO3. Stimulating the olfactory epithelium with L-alanine during the copper exposure evoked atypical EOG responses. The amplitudes and form of the EOGs changed drastically with increasing Cu2+ concentrations, with significant correlation between the reduction in EOG amplitudes and the Cu2+ concentration. The results indicate that among the copper species tested the toxic effect is caused mainly by the dissolved Cu2+ ion. The results also suggest that the Cu2+ ion exerts its toxic effects on the transduction mechanisms of the olfactory receptor cells. The different EOG profiles obtained in response to varying Cu2+ concentrations indicate that this ion affects the transduction mechanisms at different stages.


Short-term effect of a toxicant on scope for change in ascendency in a microcosm community. A need in the field of toxicity testing is the development of parallel tests applicable to all levels of biological organization: single-species tests alone cannot predict effects at ecosystem levels. Scope for change in ascendency (SfCA) is a comparative index applicable to the short-term assessment of stress effects on any biological system. The SfCA of a community, defined by analogy to scope for growth of an organism, is the balance of ascendency (network size and organization) of population inputs and outputs. It takes into account the interrelated processes of growth and development, both of which can be affected by stress factors. To illustrate this approach, the effect of atrazine on SfCA of a simple epilimnetic microcosm community was investigated. Simultaneous, short-term measurements of all carbon flows between populations were made and SfCA was calculated. Compounded effects of stress on populations, measured as a relative drop in community SfCA in the presence of atrazine, were observed within 2-3 weeks. This indicates that SfCA may be useful as a comparative index for the short-term assessment of perturbation effects. A refinement of the methodology for measuring resource flows at levels other than the organism would allow full advantage of this assessment tool to be taken.


Modulatory actions of ovine luteinizing hormone-releasing hormone and Mystus gonadotropin on gamma-BHC-induced changes in lipid levels in the freshwater catfish, Heteropneustes fossilis. Female specimens of Heteropneustes fossilis were exposed to a sublethal concentration of gamma-BHC (16 mg/liter) for 4 weeks during the preparatory and prespawning phases of their annual reproductive cycle. The effect of gamma-BHC on free fatty acids (FFA), monoglycerides (MG), diglycerides (DG), and triglycerides (TG) was monitored. gamma-BHC in general was inhibitory to lipogenesis during both of the reproductively active phases as judged by decreased levels of FFA, MG, DG, and TG. Lower doses of ovine luteinizing hormone-releasing hormone (oLH-RH) and Mystus gonadotropin (mGTH) were ineffective in modulating the impact of gamma-BHC; however, their higher doses effectively revoked the impact of gamma-BHC. From the evidence obtained here, it is concluded that gamma-BHC suppressed the action of oLH-RH and mGTH and affected lipogenesis in this species.


A comparison of test systems for assessing effects of metals on isopod ecological functions. The effects of metals on the isopod Porcellio scaber and the implication of metal pollution for the functioning of isopods in soil decomposition processes were determined. The experiments were carried out using two test systems, a simple test container without natural substrate and a micro-ecosystem with leaf litter, the latter being more comparable to the field situation. Metals were offered to the isopods by feeding artificially contaminated litter and litter from contaminated field sites. The Cd concentrations in isopods in test containers with ground litter as food were similar to those in isopods in micro-ecosystems with intact leaves as food. Exposure to artificially contaminated litter with Cd alone or litter from contaminated field sites with Cd, Pb, Zn, and Cu resulted in comparable Cd concentrations in the isopods. Growth of the isopods was not affected by Cd or by the combination of Cd, Pb, Zn, and Cu, but differed between the test systems. Fragmentation activity of isopods decreased in litter containing 155 nmol/g Cd and 33500 nmol/g Zn, sampled at a contaminated field site. CO2 production from micro-ecosystems decreased at a concentration of 1010 nmol/g Cd, but NH4 and NO3 concentrations in the litter did not respond to Cd. Isopod growth was better in micro-ecosystems. These systems are therefore recommended for ecotoxicity tests using isopods. After comparison with literature data it was concluded that the bioavailability of Cd in laboratory tests is often higher than the bioavailability in the field at the same total concentrations. This may be due to environmental heterogeneity; this gives animals food choice and is absent in many laboratory test systems. For the quantification of a laboratory-field extrapolation factor for general use, more detailed information is needed than is available now.


Tissue lead concentrations and shot ingestion in nine species of waterbirds from the Camargue (France). This study investigates the relationship among lead exposure (shot ingestion), current lead impregnation (liver lead values), current and previous lead impregnation (bone lead values), and lead excretion (feather lead) in nine species of waterbird from the Camargue (Rhone river delta), France. Results indicate that for individuals there is no readily predictable relationship between ingested shot and liver or bone lead concentrations. However, at the "population" level, and interspecifically, significant positive relationships exist between the susceptibility to shot ingestion and the degree of lead impregnation. Shoveler (Anas clypeata) proved to be an exception, with a high level of shot ingestion and no elevated tissue lead values. This is probably related to dietary factors. Species with a high degree of current lead contamination tended to be those that had also previously absorbed elevated levels of lead. Feather lead concentrations were not clearly related to the vulnerability of a species to shot ingestion or lead poisoning. There was no significant absorption of arsenic and antimony from gunshot associated with lead absorption.


Primary chemical and physical characterization of acute toxic components in wastewaters. A chemical and physical primary characterization work sheet was developed based on the Microtox test, a bacterial bioluminescence system used as a rapid estimate of acute aquatic toxic effects. Measurements of the variation in light reduction upon different pretreatments provided information about the chemical and physical properties of the main toxic component(s) in test wastewater samples. This primary characterization of a wastewater sample was performed within 1 day. Tests of pure toxic chemical compounds and wastewaters with known and unknown primary toxicants are presented. Outlines to the chemical analysis and identification of toxic components may be deduced from the primary characterization. The provisional characterization may also provide information on wastewater treatment techniques.


Cloricromene synergizes with antiplatelet drugs and nitric oxide-like factor derived from rat peritoneal polymorphonuclear cells. We report that cloricromene (5-30 microM) inhibited thrombin-induced platelet aggregation and synergized with other antiplatelet compounds. The antiaggregatory effect of subthreshold concentrations of the prostaglandin (PG)I2 analogue, iloprost (0.2 nM), or of sodium nitroprusside (1 micron), acting through a nitric oxide (NO)-like mechanism, was significantly potentiated by co-incubation with cloricromene (5 microM). In addition, cloricromene enhanced the antiplatelet activity of the NO-like factor released by peritoneal rat polymorphonuclear cells. Thus, the present results show that cloricromene possesses direct antiplatelet properties and synergizes with other endogenous as well as exogenous antiplatelet compounds.


CP-96,345 antagonism of NK1 receptors and smoke-induced protein extravasation in relation to its cardiovascular effects. The effects of the non-peptide NK1 receptor antagonist, CP-96,345, on cardiovascular homeostasis were investigated in conscious and anaesthetized rats in vivo and on heart function and muscle tonicity of vessels in vitro. CP-96,345 and its enantiomer, CP-96,344, which does not exhibit NK1 receptor-blocking activity when tested at a concentration of 1 microM, significantly decreased blood pressure in conscious rats at a dose of 0.32 mg/kg i.v. CP-96,345 and CP-96,344 additionally reduced heart rate at doses of 1 and 3.2 mg/kg, respectively. Studies in anaesthetized rats showed that ganglionic blockade did not modify the decreases in blood pressure and heart rate elicited by CP-96,345. In the isolated guinea-pig heart, CP-96,345 and CP-96,344 exerted negative chronotropic effects at 10(-7) M; negative inotropic effects were observed at 10(-6) M. At 10(-5) M, both CP-96,345 and CP-96,344 decreased the amplitude of contraction of the rat portal vein, whereas at 10(-4) M, both compounds increased the frequency of contraction of this vessel. CP-96,345, at 5 x 10(-8) M, caused relaxation of precontracted pig coronary arteries. Since both CP-96,345 and CP-96,344 produced similar changes in haemodynamics and in the contractility of vascular and cardiac tissue, the cardiovascular effects of CP-96,345 are probably not related to NK1 receptor antagonism. As only the enantiomer with NK1 antagonistic activity inhibited cigarette smoke-induced plasma protein extravasation in rat trachea, CP-96,345 remains a useful tool for elucidating NK1 receptor-mediated responses, provided CP-96,344 is included as control.


Pharmacological characterization of new cholecystokinin analogues. New analogues of cholecystokinin-7 (CCK-7) modified at amino acid residues 5 and 7 were assayed for their effect on gall bladder, pancreatic secretion, food intake (anorectic activity), amount of rearing (sedative activity) and analgesia, as well as their ability to inhibit 125I-CCK-8 binding to pancreatic cell membrane receptors and brain membrane receptors. The results were compared to the activities of standard compounds, CCK-8, cerulein, BOC-CCK-7 (BOC = tertbutyloxycarbonyl) and BOC-[Nle2,Nle5]CCK-7. All analogues exhibited agonistic effects. Their anorectic activity was significantly prolonged.


Atrial natriuretic peptide suppresses renal vasoconstriction induced by angiotensin II and norepinephrine in dogs. Atrial natriuretic peptide (ANP, 10 and 50 ng/kg per min), infused into the renal artery, suppressed decreases in renal blood flow induced by intrarenal arterial injection of angiotensin II (Ang II, 25-100 ng) and norepinephrine (NE, 0.25-1 microgram) in anesthetized dogs. Sodium nitroprusside (SNP, 0.1-5.0 micrograms/kg per min) slightly attenuated the blood flow response to Ang II but not the response to NE. 8-Bromo cyclic GMP (8bcGMP, 0.5-25 micrograms/kg per min) did not suppress the blood flow response to Ang II. Although at a high dose ANP attenuated the blood flow response to Bay K 8644 (1-4 micrograms), nifedipine pretreatment (20 micrograms/kg plus 1 microgram/kg per min i.v.) did not affect the inhibitory effect of ANP on the NE-induced response. The vaso-inhibitory effects of ANP therefore could not be related exclusively to stimulation of cGMP production or inhibition of voltage-dependent Ca2+ channels.


Effects of FR 113680 and FK 224, novel tachykinin receptor antagonists, on cigarette smoke-induced rat tracheal plasma extravasation. We examined the effects of novel tachykinin antagonists, FR 113680 (N alpha-[N alpha-(N alpha-acetyl-L-threonyl)-N1-formyl-D-tryptophyl]-N- methyl-N-phenylmethyl-L-phenylalaninamide) and FK 224 (N-[N2-[N-[N-[N-[2,3-didehydro-N-methyl-N-[N[3-(2-phenthylpheny l) - propionyl]-L-threonyl]-tyrosyl]-L-leucynyl]-D-phenylalanyl]-L-allo - threonyl]-L-asparaginyl]-L-serine nu-lactone) on rat tracheal plasma extravasation induced by cigarette smoke. Intravenous injection of FK 224 (0.032-3.2 mg kg-1) inhibited rat tracheal plasma extravasation induced by cigarette smoke and capsaicin. FR 113680 (32 mg kg-1 i.v.) also significantly inhibited cigarette smoke-induced plasma extravasation, whereas D-chlorpheniramine maleate, FPL 55712, atropine sulfate and indomethacin had no effect. Tracheal plasma extravasation induced by substance P (SP) and neurokinin A (NKA), but not histamine, was also reduced by intravenous administration of FR 113680 and FK 224. These findings suggest that cigarette smoke stimulates primary afferent sensory nerves, releases tachykinins and evokes plasma extravasation in rat trachea.


Further evidence from an elastic artery that angiotensin II amplifies noradrenaline-induced contraction through activation of protein kinase C. Angiotensin II (AII, 0.1 nM) increased concentration dependently the sensitivity of rabbit aortic rings to low concentrations of noradrenaline. This was not associated with increases in noradrenaline-induced 45Ca2+ uptake or efflux and was prevented by the protein kinase C (PKC) inhibitors staurosporine (0.01 microM) and calphostin C (0.1 microM). Pretreatment of the rings with PMA (phorbol-12-myristate-13-acetate, 0.1 and 1 microM, 24 h at 4 degrees C) abolished the potentiation phenomenon. We conclude that AII potentiation of noradrenaline-induced vascular tone may be due to a PKC-mediated increase in intracellular sensitivity of the contractile apparatus to Ca2+.


Modification of alpha-adrenoceptor-mediated pressor responses by NG-nitro-L-arginine methyl ester and vasopressin in endotoxin-treated pithed rats. Pithed rats were used to compare the abilities of vasopressin and NG-nitro-L-arginine methyl ester (L-NAME) to prevent the early (1 h after starting an endotoxin infusion) E. coli endotoxin-induced impairment of pressor responsiveness to noradrenaline, cirazoline, BHT 933 and to sympathetic stimulation (T8). L-NAME increased arterial blood pressure and augmented pressor responses to noradrenaline and to sympathetic nerve stimulation to a similar degree in control and endotoxin-treated rats. The response to the alpha 1-adrenoceptor agonist cirazoline was augmented by L-NAME in endotoxin-treated rats only, whereas the response to the alpha 2-adrenoceptor agonist BHT 933 was unaffected. Vasopressin (0.64 I.U. kg-1 h-1) prevented the hypotension that resulted from endotoxin administration and produced a similar increase in blood pressure to that produced by L-NAME. This dose of vasopressin also augmented pressor responses to noradrenaline and sympathetic nerve stimulation similarly in both control and endotoxin-treated rats. Sodium nitroprusside, in a dose that mimicked the degree of hypotension caused by endotoxin, also impaired pressor responsiveness to cirazoline; this impairment was prevented by co-infusion of vasopressin. Thus the effects of L-NAME in preventing the early phase of endotoxin-induced impairment of vascular responsiveness may be related to its hypertensive properties, due to inhibition of the constitutive form of nitric oxide synthase, rather than inhibition of endotoxin-induced nitric oxide synthase. These data suggest that early endotoxin-induced impairment of vascular reactivity probably involves factors other than nitric oxide. The well documented effect of endotoxin in inducing nitric oxide synthase probably explains the later, more sustained loss of vascular responsiveness.


Synergism between interleukin-1 beta and interferon-gamma, an inducer of nitric oxide synthase, in rat lung fibroblasts. An L-arginine-dependent pathway, by which L-arginine is metabolised to citrulline and nitrogen oxides, has been recently identified in some cell types. In cultured rat lung fibroblasts the presence of L-arginine was necessary for the production of nitrite to be induced by rat recombinant interferon-gamma and synergistically enhanced by lipopolysaccharide and interleukin-1 beta. Lipopolysaccharide and interleukin-1 beta did not induce nitrite biosynthesis by themselves. Biosynthesis was apparently dependent on tetrahydrobiopterin, since it could be blocked by diaminohydroxypyrimidine, an inhibitor of tetrahydrobiopterin synthesis. Dexamethasone blocked nitrite production by a receptor-mediated mechanism. These data indicate that rat lung fibroblasts express an L-arginine-dependent nitric oxide synthase which can be induced by some mediators of inflammation.


Glibenclamide and L-NG-nitro-arginine methyl ester modulate the ocular and hypotensive effects of calcitonin gene-related peptide. Calcitonin gene-related peptide (CGRP) given i.v. to rabbits induced hypotension and a breakdown of the blood-aqueous barrier. Glibenclamide, a blocker of ATP-sensitive K+ (K+ATP) channels antagonized both these effects. The K+ATP channel opener diazoxide reduced blood pressure but did not damage the blood-aqueous barrier. Inhibition of nitric oxide synthase antagonized the effects of CGRP on the blood-aqueous barrier but did not attenuate the hypotensive response. The results suggest that vasodilatation induced by the opening of K+ATP channels is a prerequisite for the effect of CGRP on the blood-aqueous barrier.


Effect of TGF beta on liver genes expression. Antagonistic effect of TGF beta on IL-6-stimulated genes in Hep 3B cells. The effect of transforming growth factor beta (TGF beta) on the expression of a group of liver genes has been investigated in the hepatoma cell line Hep 3B. TGF beta induces a decrease of the basal level of apolipoprotein A-II (ApoA-II), retinol binding protein (RBP) and alpha-fetoprotein (alpha Fp). Furthermore, TGF beta efficiently antagonizes the IL-6-induction of hemopexin (Hpx) and haptoglobin (Hp) and alpha 1-acid glycoprotein (AGP). These effects of TGF beta are apparently mediated by post-transcriptional mechanism(s). These findings, together with previously reported data on the inhibitory effect of TGF beta on acute phase genes (e.g. ApoA-I and albumin), suggest a role for TGF beta in the regulation of expression of liver genes.


Biochemical characterization of the p51 sub-unit of human immunodeficiency virus reverse transcriptase in homo- and heterodimeric recombinant forms of the enzyme. The biochemical properties of the p51 subunit of HIV-1 reverse transcriptase (RT) were studied in order to understand its role in the heterodimeric form p66/p51 found in virions. A recombinant form of RT, p51/p51, expressed in yeast, was purified and characterized. The enzyme was affinity labeled using a 5' modified oligonucleotide primer, covalently linked, that was further elongated in the presence of a radioactive dNTP precursor. We found that the p51 subunit was labeled in the p51/p51 form, thus reflecting its activity, while this subunit was catalytically silent in the heterodimer, since only the p66 subunit was labeled in the latter recombinant form. Processivity studies showed long-sized products synthesized by p51/p51, as in the case of the other RT forms. The effect of primer tRNA(Lys) on the p51/p51 activity showed a strong inhibitory effect in the absence of KCl, similar to that observed with the p66/p51 form, while the same p51/p51 enzyme was strongly stimulated by tRNA(Lys), like RT p66/p66, when KCl was present in the incubation mixture.


Changes in chromatin structure due to hypomethylation induced with 5-azacytidine or DL-ethionine. Changes in chromatin structure of the HRS60 family of repetitive sequences in tobacco DNA were studied after hypomethylation induced with 5-azacytidine or DL-ethionine. The TaqI site in the HRS60 units lies in nucleosomal core regions and its cleavage is enhanced in the hypomethylated chromatin. In contrast, the cleavage of the Sau3AI site located in linker DNA does not depend on the level of methylation of DNA.


The amphicrine pancreatic cell line, AR42J, secretes GABA and amylase by separate regulated pathways. Treatment of AR42J cells with dexamethasone leads to an enhanced formation of amylase-containing granules and facilitates their regulated secretion. Besides the exocrine properties, AR42J cells possess a specific uptake system for [3H]GABA. The stored GABA can be released upon potassium depolarisation in a Ca(2+)-dependent manner. After treatment with dexamethasone, potassium depolarisation fails to release GABA, but instead causes a Ca(2+)-dependent secretion of amylase. Since vesicles similar to small synaptic vesicles of neurons have been identified in AR42J cells, we suggest that the regulated GABA release is mediated by this vesicle type. It is tentatively speculated that other epithelial cells, which also contain small synaptic vesicles and amino acid neurotransmitters, may release them in a similar fashion.


Inhibition of actin-activated myosin Mg(2+)-ATPase in smooth muscle by ruthenium red. Ruthenium red was found to inhibit actin-activated myosin Mg(2+)-ATPase in smooth muscle and to bind to myosin heavy chain, but not to F-actin. The inhibition by Ruthenium red of actin-activated Mg(2+)-ATPase was of the competitive type with respect to actin (Ki 4.4 microM) and of the non-competitive type with respect to ATP (Ki 6.6 microM). However, Ruthenium red scarcely dissociated the acto-heavy meromyosin complex during the ATPase reaction. These results suggest that Ruthenium red interacts directly with the binding site for F-actin on the myosin heavy chain. This site is considered to be necessary not for maintaining the binding affinity of myosin for F-actin, but for activation of the Mg(2+)-ATPase.


Altering the course of proliferative nephritides: the challenge of the 1990s. There is considerable evidence based on experimental pathology that heparin/heparinoids will benefit the course of the various forms of human proliferative nephritis. An alternative to heparin may be pentosan polysulphate. Another possibility is the infusion of prostaglandin E1 because of its anti-inflammatory and potentially antiproliferative actions. Both these approaches mimic natural pathophysiological control mechanisms.


Effects of biological response modifiers with different modes of action used separately and together on immune responses in mice with syngeneic tumours. The effect of a protein-bound polysaccharide (PSK) obtained from cultured mycelia of the Basidiomycetes Coriolus versicolor on activities involved in the host defence mechanism of C57BL/6 mice bearing adenocarcinoma 755 was compared with that of live bacille Calmette-Guérin (BCG). Delayed footpad reaction, the activity of splenic natural killer cells and interferon production induced by concanavalin A in splenic cells of healthy mice were little affected by PSK, but in mice bearing tumours PSK prevented the tumour-induced reduction in these activities. Live BCG augmented these activities in healthy mice but had little effect on the reduction of activities induced by a tumour. The immunosuppressive activity of the serum of tumour-bearing mice was reduced by PSK administration; live BCG did not have this effect. The combined use of live BCG and PSK improved these activities in the host, with synergistic increases in the antitumour effect. These results suggest that the combined use of live BCG and PSK, which have different modes of action, may be useful in the treatment of cancer.


Modulation of embryonic and muscle-specific enolase gene products in the developing mouse hindlimb. During striated muscle development, the glycolytic enzyme enolase (EC 4.2.1.11) undergoes an isozymic transition, from the embryonic alpha alpha form towards the muscle-specific forms alpha beta and beta beta. The regulation of this transition was analyzed in mouse hindlimb muscles from embryonic day 15 (E15) to the adult stage. The quantitative modulations of the levels of the transcripts and subunits of alpha and beta enolase genes were determined. The absolute amounts of alpha and beta enolase mRNAs were estimated using in vitro synthesized transcripts as calibration standards, thus allowing an evaluation of their relative contribution at each stage examined. The muscle-specific beta enolase mRNA is already present at E15. Its level then increases and, from E17, this transcript becomes predominant. This accumulation is biphasic: a steep prenatal rise, corresponding to a net increase per fiber, accompanies the formation of secondary myofibers and the development of innervation; a second rise, beginning at postnatal day 5, is temporally correlated with the definitive specialization of the myofibers. Most of the decrease in alpha mRNA level occurs postnatally. No temporal or quantitative correlation between the up-regulation of beta mRNA and the down-regulation of alpha mRNA levels is observed throughout hindlimb muscle development. Quantitative immunoblotting analyses carried out in parallel show that the enolase isozymic transition is mainly controlled at the mRNA level.(ABSTRACT TRUNCATED AT 250 WORDS)


Widespread differentiation stage-specific expression of the gene encoding phosphoprotein p19 (metablastin) in mammalian cells. p19 is a highly conserved 19 kD cytosolic protein that undergoes phosphorylation in response to diverse extracellular factors in mammalian cells. Its expression is abundant in brain and testis and is developmentally regulated. To gain insights regarding its function, we analyzed the expression of p19 mRNA in a variety of cell types during induction of differentiation. Murine erythroleukemia cells showed a moderate increase followed by a marked decrease in the abundance of p19 mRNA during induction of differentiation. In murine C2 myoblasts and primary fetal rat osteoblasts, p19 mRNA was abundant in replicating cells and decreased to undetectable levels during differentiation. In resting human peripheral blood lymphocytes, p19 mRNA was virtually undetectable but was strongly induced during blast transformation of both B and T cells. In rat liver, p19 mRNA was abundant on embryonic day 17 and decreased during early postnatal development. Upon fractionation of adult rat liver cells by centrifugal elutriation, p19 mRNA was not detected in hepatocytes while a low level was observed in a fraction enriched in non-parenchymal epithelial cells. CCl4-induced liver regeneration resulted in induction of p19 mRNA in hepatocytes. Primary cultures of embryonic and neonatal rat brain were analyzed by indirect immunofluorescence using co-staining with stage-specific markers. p19 expression was restricted to immature neurons and oligodendrocyte precursors. In contrast to the other cell types examined, the neuronal and glial precursors that express p19 were shown, using BrdU labeling, to be postmitotic both in primary culture and in vivo. The data demonstrate widespread, stage-specific expression of p19 and suggest that the protein exerts a general, lineage-independent function during induction of differentiation of mammalian cells. In view of the available evidence on the stimulation of serine phosphorylation of p19 by several growth factors, our working hypothesis is that phosphorylation of p19 may be involved in the mechanism by which growth factors control cell differentiation.


Characterization of the Salmonella typhimurium phoE gene and development of Salmonella-specific DNA probes. In Escherichia coli K-12, the phoE gene, encoding a phosphate-limitation-inducible outer membrane pore protein (PhoE), is closely linked to the genes proA and proB. When the corresponding fragment of the Salmonella typhimurium chromosome was transferred to E. coli K-12 using an RP4::miniMu plasmid, pULB113, no production of S. typhimurium PhoE could be detected. Nevertheless, DNA hybridization studies revealed that the corresponding plasmid did contain S. typhimurium phoE. Production of S. typhimurium PhoE in E. coli was detected only after subcloning the gene in a multicopy vector. Nucleotide (nt) sequence analysis showed extensive homology of S. typhimurium phoE to the E. coli gene and suggested possible explanations for the low expression of S. typhimurium phoE in E. coli. In addition, the sequence information was used to develop Salmonella-specific DNA probes. Two oligodeoxyribonucleotides were synthesized based on nt sequences encoding the fifth and eighth cell-surface-exposed regions of PhoE. When used in polymerase chain reactions, these probes turned out to be specific, i.e., no crossreactions occurred with the non-Salmonella strains, whereas 132 out of 133 tested Salmonella strains were recognized.


Coeliac disease: characterisation of monoclonal antibodies raised against a synthetic peptide corresponding to amino acid residues 206-217 of A-gliadin. A dodecapeptide of A-gliadin, which shares amino acid homologies with the E1b protein of adenovirus 12, was used to produce murine monoclonal antibodies. Five monoclonal antibodies were produced and were screened by enzyme linked immunosorbant assay, immunodot assay, and immunoblotting. The antibodies were tested against whole wheat gliadin and its alpha, beta, gamma, and omega subfractions, and the prolamins of rye, barley, oats, maize, millet, rice, and sorghum. Four of the five antibodies cross reacted with one or more of the coeliac non-toxic cereals--maize, millet, sorghum, and rice. The monoclonal antibody that did not cross react with these non-toxic cereals, did not recognize Frazer's fraction III, a peptic-tryptic digest of wheat gluten which is known to be toxic. The results suggest that the A-gliadin dodecapeptide shares a region of homology with cereals that do not exacerbate coeliac disease. This study does not support the hypothesis that prior infection with adenovirus 12 is a precipitating factor in coeliac disease.


Importance of endogenous prostaglandins for the toxicity of cyclosporin A to rat endocrine and exocrine pancreas? Previous work has shown that cyclosporin A is toxic to the endocrine and exocrine pancreas. The aim of this study was to examine whether endogenous eicosanoids play a role in controlling cyclosporin A induced toxicity. Rats were treated for eight days with indomethacin (2 mg/kg, twice daily) in addition to cyclosporin A (5 or 10 mg/kg daily). Effects of drug treatments on exocrine (as assessed by amylase and protein secretion into the pancreatic juice) and endocrine (as assessed by the glucose dependent insulin release) pancreatic functions, and pancreatic formation of prostaglandins and thromboxane were evaluated. Treatment with cyclosporin A in the doses used did not inhibit eicosanoid formation by the pancreatic tissue ex vivo. Indomethacin caused significant inhibition of pancreatic formation of prostaglandin E2, 6k prostaglandin F1 alpha and thromboxane B2. Combined treatment with indomethacin and cyclosporin A (5 or 10 mg/kg) augmented cyclosporin A induced pancreatic toxicity with further impairment of insulin release, amylase secretion, and pancreatic juice protein content, but did not result in more pronounced inhibition of pancreatic eicosanoid formation. The increased toxicity of the combined treatment was, however, associated with raised cyclosporin A whole blood concentrations. The data suggest that the potentiation of pancreatic toxicity of cyclosporin A observed during coadministration of indomethacin is not the result of suppression of endogenous pancreatic eicosanoid biosynthesis, but more likely results from altered cyclosporin A pharmacokinetic which may be caused by an interference of indomethacin with the hepatic cytochrome P-450 dependent monooxygenase involved in cyclosporin A metabolism. The possibility that coadministration of non-steroidal antiinflammatory drugs aggravates toxic effects in cyclosporin A treated patients should be considered.


Stimulatory effect of oCRH on alpha-subunit secretion during petrosal sinus sampling in patients with Cushing's disease. During bilateral and simultaneous venous sampling of the inferior petrosal sinuses for preoperative localization of ACTH secreting microadenomas, alpha-subunit levels, in addition to ACTH, were determined in 9 patients with Cushing's disease. The aim of the study was to evaluate the possible occurrence of unilateral increases of alpha-subunit in basal conditions and the alpha-subunit responsiveness to oCRH. All the patients examined showed a central to peripheral and an intersinus gradient of ACTH concentrations before and/or after oCRH stimulation. Seven patients showed a central to peripheral alpha-subunit gradient in basal conditions. Lateralization of alpha-subunit concentrations was recorded in 4 patients in basal conditions (intersinus gradient > or = 1.55) and paralleled the side with the highest ACTH concentrations. After oCRH stimulation all but one patient showed a unilateral alpha-subunit increase in blood from the inferior petrosal sinus with the highest oCRH stimulated ACTH increase. The present data confirm the occurrence of an increase of alpha-subunit concentration in response to nonspecific stimulation with exogenously administered oCRH, concurrent with an ipsilateral increase of ACTH levels. The mechanism underlying this finding is still unclear, although a paracrine effect from the corticotroph tumour on adjacent pituitary tissue seems so far the most likely explanation.


Insulin-like growth factor binding protein 1 (IGFBP-1) levels in Turner syndrome. We tested whether IGFBP-1, a modulator of IGF-I action, would play a role in the pathogenesis of growth failure and metabolic picture of Turner syndrome. Fasting serum levels of IGFBP-1 were assessed in nineteen girls with Turner syndrome (aging 6.5 to 17.2 years) by radioimmunoassay. Our patients showed normal values of IGFBP-1 (mean +/- SD: 68.6 +/- 32.5 micrograms/l, range: 16 to 134 micrograms/l; range for age and pubertal stage-matched normal children: 15 to 180 micrograms/l). IGFBP-1 levels inversely correlated with bone age (p < 0.05), weight (p < 0.001), percentage of ideal body weight (p < 0.002) and body mass index (BMI) (p < 0.001). Our results seem to rule out a role of IGFBP-1 in the pathogenesis of growth failure in Turner syndrome. The close inverse relationship between IGFBP-1 levels and BMI suggests the serum concentrations of IGFBP-1 to be regulated by the nutritional status. Due to IGFBP-1 inhibiting action on IGF biological activity, the reduction of IGFBP-1 levels in overweight subjects might represent a mechanism to enhance the IGF insulin-like activity, thus supplementing the insulin action.


Intermediate filament expression in mesotheliomas: leiomyoid mesotheliomas are not uncommon. In this study we examined intermediate filament expression in 45 formalin-fixed mesotheliomas. Immunostaining for cytokeratin was found in 86%, for vimentin in 71%, and for desmin in 4%; none stained for glial fibrillary acidic protein or neurofilament. The two biphasic mesotheliomas which expressed desmin also expressed smooth muscle actin but were negative for myoglobin. This, together with the ultrastructural findings, was taken as unequivocal evidence of a leiomyoid form of mesothelioma which might easily be confused with leiomyosarcoma. Both of these tumours co-expressed cytokeratin, exemplifying the value of cytokeratin immunostaining in the distinction between mesothelioma and sarcoma. Consistent non-expression of glial fibrillary acidic protein in mesotheliomas may help to distinguish them from nerve sheath tumours.


Microwave effects on input resistance and action potential firing of snail neurons. Excitable tissues have been reported to respond to weak microwave (MW) fields, possibly by nonlinear perturbation of a cellular process such as ion conduction across membranes. We sought effects of MW (continuous wave, 2.45 GHz, specific absorption rates 12.5 or 125 mW/g) on input resistances and action potential (AP) intervals of neurons in ganglia of snails (Helix aspersa), at 20.9 +/- 0.1 degrees C. At 12.5 mW/g, input resistance did not change during irradiation, but increased (p < 0.05) afterward. At 125 mW/g, input resistance during irradiation was lower than in unirradiated controls. Serial correlograms changed marginally more frequently in MW experiments than in controls, but the changes had no consistent pattern. The AP firing rate was affected by MW, but the direction was not consistent across cells. When AP generation was modeled as being due to a neuronal input current, MW did not affect its mean, standard deviation, or autocorrelation. Unlike MW, temperature changes caused neurons to respond robustly and reversibly. Threshold for changing input resistance was 0.63 degree C. The data suggest that MW may enhance degenerative effects such as metabolic rundown or loss of ion channel patency, but do not indicate a specific mechanism for MW interaction with neurons.