Whole-cell patch study of GABAergic inhibition in CA1 neurons of immature rat hippocampal slices

Inhibitory processes mediated by gamma-aminobutyric acid (GABA) were studied in immature rat hippocampal slices using the whole-cell patch clamp technique. Orthodromically evoked hyperpolarizing inhibitory postsynaptic potentials (IPSPs) were observed in CA1 neurons of postnatal 2-5 (P2-5) and 7-13 (P7-13) day old rats under conditions of low internal [Cl-]. In the whole-cell voltage-clamp mode, applications of GABA evoked outwards currents which reversed at -55 mV and -62 mV in P2-5 and P7-13 CA1 neurons, respectively, with comparable reversal potential for the IPSPs for each age. An increase in internal [Cl-] caused a depolarizing shift of the GABA reversal potential which followed the Nernst equation. In both groups of neurons, the IPSPs and GABA currents were blocked with the bath applications of bicuculline (10 microM) and picrotoxin (100 microM). We conclude that the GABAA-mediated inhibitory synaptic process exists in P2-5 CA1 neurons and hypothesize that the absence of such IPSPs noted in previous studies of immature CA1 neurons was likely due to higher internal [Cl-] in the more immature neurons.

Potential of hypertonic medium treatment for embryo micromanipulation: II. Assessment of nuclear transplantation methodology, isolation, subzona insertion, and electrofusion of blastomeres to intact or functionally enucleated oocytes in rabbits

The objective of this research was to study efficiency of embryo development following transfer of blastomeres into the perivitelline space of oocytes. Single blastomeres from 8-, 16-, and 32-cell embryos were obtained following mucin coat and zona pellucida removal by combined treatments with pronase and acidic phosphate-buffered saline (PBS, pH = 2.5). Blastomeres were separated by pipetting with a fire-polished micropipette following incubation in Ca+(+)-free PBS for 15 min at 39 degrees C. This procedure resulted in over 97% blastomere separation. For ease of blastomere insertion, oocytes were placed in droplets of 0.5 M sucrose in PBS (SPBS) during micromanipulation. To functionally enucleate oocytes some were stained with Hoechst 33342 DNA stain and irradiated. A single 8- or 16-cell blastomere was aspirated into an injection pipette (35 microns or 25 microns at the tip, respectively) and inserted into the perivitelline space of an irradiated or non-irradiated oocyte, but not fused with the oocyte. This micromanipulation procedure did not affect development of individual blastomeres into blastocysts or trophectoderm vesicles when compared with cultured control single blastomeres (P greater than .05). When the inserted blastomere was induced to fuse with an intact non-irradiated oocyte under an electric field, 56-57% were fused and 39-45% of the fused and activated oocytes developed to morulae or blastocysts. When an inserted blastomere (from 8-32-cell embryos) was induced to fuse with a functionally enucleated oocyte treated by Hoechst 33342 staining, followed by washing and UV-light irradiation, 63-66% of them were fused, but only 15-22% developed to the morula or blastocyst stage. This research demonstrated that the use of hypertonic medium treated oocytes greatly improved the ease and success rate of blastomere subzona insertion, but the value of functionally enucleated oocytes as recipient cells for nuclear transfer requires further investigation.

Characterization of beta-adrenoreceptors on smooth muscle cells from guinea pig stomach

To characterize the beta-adrenergic receptors on guinea pig gastric smooth muscle cells, we examined the effects of beta-adrenergic agonists and antagonists on biological activity, cellular adenosine 3',5'-cyclic monophosphate (cAMP), and radioligand binding. Adrenergic agonists, isoproterenol (ISO), epinephrine (EPI), and norepinephrine (NE), inhibited carbachol-stimulated contraction of muscle cells, with relative potencies (IC50S) of ISO (0.1 microM) greater than EPI (1.4 microM) greater than NE (11 microM). Each agonist increased cellular cAMP, with relative potencies (IC50S) of ISO (0.5 microM) greater than EPI (6.3 microM) greater than NE (56 microM). Binding of the nonselective beta-antagonist 125I-pindolol was temperature-dependent, saturable, reversible, and specific. 125I-pindolol binding was inhibited by the three agonists, with relative potencies (IC50S) of ISO (0.9 microM) greater than EPI (9.6 microM) greater than NE (112 microM). Pindolol inhibited binding of 125I-pindolol with an IC50 of 100 nM. The IC50 for inhibition of binding of 125I-pindolol by the relatively beta 2-selective antagonist ICI 118,551 was 70 nM and for the relatively beta 1-selective antagonist betaxolol was 1,000 nM. Computer analysis of the dose-inhibition curves for binding of 125I-pindolol for the antagonists indicated that gastric smooth muscle cells possess exclusively beta 2-adrenergic receptors of two classes, one class with a high affinity for ICI 118,551 (Kd = 50 nM) and the other with a low affinity for ICI 118,551 (Kd = 30 microM). Our results indicate that beta-adrenergic agonists interact with beta 2-adrenergic receptors on gastric smooth muscle cells to increase cellular cAMP and inhibit muscle contraction.

[Modulation of norepinephrine release in sympathetic nerve endings in renal hypertensive dogs]

Experimental renal hypertensive and normal dogs with femoral arteries constantly perfused were studied. Cocaine was used to block the presynaptic norepinephrine (NE) reuptake and tyramine to initiate the release of NE in sympathetic nerve endings. NE spillover and infusion pressure were measured under basic conditions and during intraarterial infusion of cocaine, tyramine and in combination with alpha 1 and alpha 2 adrenoceptor antagonists. The extent of NE spillover increase induced by infusion of tyramine, the increased infusion pressure by cocaine and tyramine, and the reduced infusion pressure by prazosin were all greater in hypertensive dogs than those in normal dogs, but adrenoceptor antagonist idazoxan further increased tyramine-induced NE spillover in normal dogs only. It was suggested that reduced-regulation of presynaptic alpha 2 adrenoceptors to NE release and increased responsiveness of postsynaptic alpha 1 adrenoceptors to NE were present in hypertensive dogs.

Comparison of Rous sarcoma virus RNA processing in chicken and mouse fibroblasts: evidence for double-spliced RNA in nonpermissive mouse cells

Rous sarcoma virus, an avian retrovirus, transforms but does not replicate in mammalian cells. To determine to what extent differences in RNA splicing might contribute to this lack of productive infection, cloned proviral DNA derived from the Prague A strain of Rous sarcoma virus was transfected into mouse NIH 3T3 cells, and the viral RNA was compared by RNase protection with viral RNA from transfected chicken embryo fibroblasts by using a tandem antisense riboprobe spanning the three major splice sites. The levels of viral RNA in NIH 3T3 cells compared with those in chicken embryo fibroblasts were lower, but the RNA was spliced at increased efficiency. The difference in the ratio of unspliced to spliced RNA levels was not due to the increased lability of unspliced RNA in NIH 3T3 cells. Although chicken embryo fibroblasts contained equal levels of src and env mRNAs, spliced viral mRNAs in NIH 3T3 cells were almost exclusively src. In NIH 3T3 cells the env mRNA was further processed by using a cryptic 5' splice site located within the env coding sequences and the normal src 3' splice site to form a double-spliced mRNA. This mRNA was identical to the src mRNA, except that a 159-nucleotide sequence from the 5' end of the env gene was inserted at the src splice junction. Smaller amounts of single-spliced RNA were also present in which only the region between the cryptic 5' and src 3' splice sites was spliced out. The aberrant processing of the viral env mRNA in NIH 3T3 cells may in part explain the nonpermissiveness of these cells to productive Rous sarcoma virus infection.

Receptor mechanisms for 5-hydroxytryptamine (5-HT) in isolated ovine umbilical vein

5-Hydroxytryptamine (5-HT) and 2,5-dimethoxy-4-methyl-amphetamine (DOM) produced a concentration-dependent contraction in isolated umbilical veins obtained from fetal lambs within 2 weeks of term. Contractions to 5-HT were antagonized by ketanserin, mianserin and methiothepin with the dissociation constants (KB) being 2.17 +/- 0.36, 1.37 +/- 0.55 and 1.98 +/- 0.48 nM, respectively. The order of potency of serotonergic agonists in this tissue was: DOM greater than 5-HT greater than alpha-methyl-5-HT greater than 1(3-chlorophenyl) piperazine (mCPP) greater than m-trifluoromethyl-phenylpiperazine (TFMPP) greater than 8-hydroxy-dipropylaminotetralin (8-OH-DPAT) = 2-methyl-5-HT. alpha-Methyl-5-HT was a full agonist compared to 5-HT. DOM possessed greater affinity but less efficacy than that of 5-HT. The affinities and efficacies of the other agonists studied were lower than those of 5-HT. Variation in the sensitivity and potency of agonists is primarily due to variations in their affinity for 5-HT receptors. Assessment of receptor occupancy vs. functional response demonstrated very little, if any, receptor reserve for 5-HT receptors in this tissue. Contractile responses to DOM, 8-OH-DPAT, mCPP and 2-methyl-5-HT were effectively blocked by ketanserin. The dissociation constants (KB) of ketanserin against these agonists were as follows: DOM, 2.78 +/- 0.85 nM; 8-OH-DPAT, 3.47 +/- 1.12 nM; mCPP, 1.45 +/- 0.51 nM; 2-methyl-5-HT, 1.99 +/- 0.74 nM. The dissociation constant of MDL 72222 (3-tropanyl-3,5-dichlorobenzoate) vs. 5-HT was 13833 nM. No antagonism by prazosin (10(-7) M) or yohimbine (10(-7) M) of the responses to 5-HT was observed. These results indicate that 5-HT2 receptors are present in the ovine umbilical vein. 5-HT3 receptors were not present in this tissue. Activation of alpha-adrenoceptors was not involved in the contractions to 5-HT.

Effects of inositol, 1,4,5-trisphosphate injections into cat spinal motoneurons

Inositol 1,4,5-trisphosphate (IP3) was injected iontophoretically into cat spinal motoneurons in pentobarbital-anaesthetized cats and nonanaesthetized, decerebrate cats. Injections of IP3 induced a long-lasting, reproducible hyperpolarization without consistent change in input resistance. The peak amplitude of post-spike afterhyperpolarization (AHP) was significantly increased by IP3 when the membrane potential was adjusted to the control level. Intracellular injections of Ca2+ chelators, which depressed the Ca2(+)-activated AHP, prevented the IP3-induced long-lasting hyperpolarization, suggesting that IP3 acts by a Ca2(+)-dependent mechanism. Intracellular injections of myo-inositol did not consistently induce hyperpolarizations. Also intracellular injections of Li+, which blocks IP3 catabolism, did not prevent the IP3-evoked hyperpolarization. These data suggest that IP3 itself, rather than its breakdown product myo-inositol, is mainly responsible for the hyperpolarizing effect. Possible mechanisms for the IP3-induced hyperpolarization are discussed.

Plant regeneration from cotyledon protoplasts of Xinjiang muskmelon

Cotyledon protoplasts were isolated from seedlings of Xinjiang muskelon (Cucumis melo var.saccharinus) grown under sterile conditions and cultured in modified Miller medium. High frequency division of the protoplast-derived cells was observed. Agarose bead culture with B6S3 tobacco crown gall nurse cells was found most suitable for the cotyledon protoplasts when compared with other culture methods. Intact plants were regenerated from the protocalli by a two-step culture procedure with liquid and then solid media.

Virtual clock: a new traffic control algorithm for packet switching networks

A challenging research issue in high speed networking is how to control the transmission rate of statistical data flows. This paper describes a new algorithm, VirtualClock, for data traffic control in high-speed networks. VirtualClock maintains the statistical multiplexing flexibility of pocket switching while ensuring each data flow its reserved average throughput rate at the same time. The algorithm has been tested through simulation.

Heterogeneity in direct cytotoxic function of L3T4 T cells. TH1 clones express higher cytotoxic activity to antigen-presenting cells than TH2 clones

In the process of generating culture supernatant from T cell clones, with anti-CD3 antibodies and the B lymphoma A20 as APC, a striking difference in the stimulation of TH1 and TH2 clones was observed, i.e., TH2 clones produced higher levels of lymphokines than TH1 clones. This prompted us to test the hypothesis that differential killing of APC (thus the removal of stimuli) by T cells led to differential T cell activation. By studying a panel of five TH1 and seven TH2 clones, it was demonstrated that TH1 clones mediated significantly higher levels of cytotoxicity toward A20 cells in the presence of soluble anti-CD3 antibody (as opposed to immobilized anti-CD3). Although T cell clones could, when activated with immobilized anti-CD3, produce lymphokines cytotoxic to A20 cells, experiments in which lymphokine production was blocked indicated that T cell clones, in the presence of soluble anti-CD3, mediated killing of A20 through direct cytotoxicity. A higher level of cytotoxicity, by TH1 compared with TH2 clones, was not restricted to anti-CD3 or a particular target cell type, because it also occurred with Con A- or Ag-dependent killing (a monocyte-macrophage cell line), and LPS blasts. Furthermore, the higher cytotoxic activity of TH1 clones compared with TH2 clones was independent of the stage of T cell activation and was unlikely a result of the length of in vitro culture. High levels of killing of APC led to low levels of T cell activation, the significance of which may be as a negative feedback mechanism in the immune response. Other biologic relevancies of higher cytotoxic activity in TH1 vs TH2 cells were also discussed.

Heterogeneity in direct cytotoxic function of L3T4 T cells. TH1 clones express higher cytotoxic activity to antigen-presenting cells than TH2 clones

In the process of generating culture supernatant from T cell clones, with anti-CD3 antibodies and the B lymphoma A20 as APC, a striking difference in the stimulation of TH1 and TH2 clones was observed, i.e., TH2 clones produced higher levels of lymphokines than TH1 clones. This prompted us to test the hypothesis that differential killing of APC (thus the removal of stimuli) by T cells led to differential T cell activation. By studying a panel of five TH1 and seven TH2 clones, it was demonstrated that TH1 clones mediated significantly higher levels of cytotoxicity toward A20 cells in the presence of soluble anti-CD3 antibody (as opposed to immobilized anti-CD3). Although T cell clones could, when activated with immobilized anti-CD3, produce lymphokines cytotoxic to A20 cells, experiments in which lymphokine production was blocked indicated that T cell clones, in the presence of soluble anti-CD3, mediated killing of A20 through direct cytotoxicity. A higher level of cytotoxicity, by TH1 compared with TH2 clones, was not restricted to anti-CD3 or a particular target cell type, because it also occurred with Con A- or Ag-dependent killing (a monocyte-macrophage cell line), and LPS blasts. Furthermore, the higher cytotoxic activity of TH1 clones compared with TH2 clones was independent of the stage of T cell activation and was unlikely a result of the length of in vitro culture. High levels of killing of APC led to low levels of T cell activation, the significance of which may be as a negative feedback mechanism in the immune response. Other biologic relevancies of higher cytotoxic activity in TH1 vs TH2 cells were also discussed.

Analysis of HLA-DQB and HLA-DPB alleles in Graves' disease by oligonucleotide probing of enzymatically amplified DNA

We have tested the possible association of HLA-DQB and HLA-DPB alleles with Graves' thyrotoxicosis, with or without severe ophthalmopathy, by polymerase chain amplification of genomic DNA and allele-specific oligonucleotide probing. There was no significantly abnormal distribution of DQB alleles compared to 50 control subjects except for a reduced prevalence of DQw 3.1 in the Graves' patients with severe ophthalmopathy (X2 = 6.23, P less than 0.02). HLA-DPB 2.1/8 was found in only 1 of 40 of these patients compared with 15 of the controls (X2 = 11.49, P less than 0.001). Ten of 48 patients with Graves' disease but without clinically significant eye involvement were HLA-DPB 2.1/8 positive, not significantly different from controls, but significantly different from the ophthalmopathy group (X2 = 6.70, P less than 0.01). The other DPB alleles in both groups of Graves' disease patients were the same as controls. These results suggest that HLA-DPB 2.1/8 may confer a protective effect in Graves' disease with respect to ophthalmopathy.

Human suppressor T cell clones lack CD28

Previously we showed that certain T cell lines and clones from a lepromatous leprosy patient displayed a dose-dependent suppression of the proliferation of autologous T cells to Mycobacterium leprae (M. leprae) but not mitogen or an unrelated antigen. The latter cells were also cloned and did not display this suppressive activity, were CD4+ and proliferated vigorously to M. leprae presented by autologous HLA-DR molecules. We shall refer to these cells as T helper (Th) cells. Most of the suppressive T cell clones (Ts) were also CD4+ and also proliferated to M. leprae presented by HLA-DR, but much less strongly than Th cells. In this study we report on our search for (a) the mechanism of this apparently antigen-specific suppression by T cells, and (b) a possible phenotypic difference between Th and Ts clones. The two main conclusions are that Ts clones possess a lytic machinery, but that M. leprae-specific suppression and cytotoxicity can be clearly dissociated, and that the only phenotypic difference between Th and Ts is the presence of the CD28 marker on Th and its absence on Ts clones.

Characterization of 5-hydroxytryptamine receptors on isolated ovine uterine artery in late pregnancy

5-Hydroxytryptamine (5-HT) and 2,5-dimethoxy-4-methyl-amphetamine (DOM) are potent agonists on isolated ovine uterine arteries in late pregnancy. Similar pA2 values (8.56 and 8.33, respectively) of ketanserin, tested against 5-HT and DOM, indicate that responses produced by both agonists are mediated by the 5-HT2 receptor. The contractions produced by 8-OH-DPAT and 2-methyl-5-HT were also blocked by ketanserin (10(-8) M) with the dissociation constants (KB) being 2.49 and 2.88 nM, respectively. This provides evidence that these agonists are activating 5-HT2 receptors in the ovine uterine artery. DOM was more potent than 5-HT, but had a similar efficacy to that of 5-HT. The greater affinity of DOM may explain its greater potency. The dissociation constants (KA) of 5-HT and DOM acting on 5-HT receptors were determined by analysis of concentration-response data before and after fractional inactivation of receptors with dibenamine. The mean KA values for 5-HT and DOM were 3.7 +/- 0.7 x 10(-7) and 1.8 +/- 0.3 x 10(-7) M, respectively. Assessment of receptor occupancy vs. functional response demonstrated little or no receptor reserve in this tissue. Several other 5-HT receptor agonists caused contractions but were much less potent than 5-HT. The order of potency of these agonists was determined to be DOM greater than 5-HT greater than or equal to alpha-methyl-5-HT much greater than 8-hydroxy-dipropylaminotetralin (8-OH-DPAT) greater than 2-methyl-5-HT greater than 1-(3-chlorophenyl) piperazine (mCPP) greater than m-trifluoromethyl-phenylpiperazine (TFMPP).(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of high carbohydrate and high fat diets on plasma glucose, insulin and lipids in normal and hypertriglyceridemic subjects]

The fasting plasma glucose, insulin and lipids response to high-carbohydrate-low-fat diets and low-carbohydrate-high-fat diets in normal subjects and patients with endogenous hypertriglyceridemia was observed. The normal, high carbohydrate and high fat diets consisted of 60%, 80% and 40% carbohydrate, 25%, 5% and 45% fat and 15% protein of total calorie respectively. The fasting plasma glucose levels increased (P less than 0.01) on day 1, insulin increased on day 3 (P less than 0.01 and P less than 0.05) and TG levels increased on days 3 and 5 after taking high carbohydrate diets both in the normal and hypertriglyceridemic groups. The fasting plasma TC and HDL-C decreased on high carbohydrate diets mainly in the hypertriglyceridemic group. The fasting plasma glucose slightly decreased on day 5, TG decreased on day 1 (P less than 0.05) and TC increased on day 1 and 3 (P less than 0.01) after taking high fat diets, but no differences were observed in insulin levels. Fasting plasma HDL-C levels in the normal group remained unchanged, but significantly decreased 3 days after taking high fat diets in the hypertriglyceridemic group (P less than 0.001). Our results indicate that high carbohydrate intake may be an important cause of hypertriglyceridemia in our country. This diet may cause a slight increase in the blood glucose level, which in turn stimulates an increase in plasma lipids and decrease in HDL-C, which is associated with an increase in the incident of coronary heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)

[Antitumor action of lignum sappan]

The aqueous extract of lignum sappan can kill cell lines of HL-60, K562, L929 and Yac-1 at the concentration of 2 microliters/ml. The survival time of mice bearing EAC is increased by 185% (P less than 0.01) by ip 0.2 ml/mouse x 7d. The three-stage sequential test standard can be passed smoothly.

Interactions of corticotropin-releasing factor with antidepressant and anxiolytic drugs: behavioral studies with pigeons

A number of studies have shown significant interactions between neuronal systems involved with corticotropin-releasing factor (CRF) and either the clinical manifestations of depression and anxiety or the effects of antidepressant or anxiolytic drugs. In the present study, effects of CRF were studied alone and in combination with imipramine and with the sedative-hypnotic/anxiolytic drugs pentobarbital and chlordiazepoxide. Interactions of CRF with the novel, atypical anxiolytic buspirone were also examined. Interactions were evaluated through the use of schedule-controlled responding, responding suppressed by punishment, and drug discrimination procedures using the conditioned key-pecking response of pigeons. Effects of CRF were significantly enhanced when given in combination with imipramine with low noneffective imipramine doses potentiating the rate-reducing effects of CRF. Similarly, in pigeons trained to discriminate imipramine from saline, noneffective doses of CRF shifted the imipramine dose-response curve more than twofold to the left. Low doses of imipramine that produced saline key responding, produced imipramine-key responding when coadministered with CRF. The CRF antagonist alpha-helical CRF9-41 did not alter the rate-decreasing effects of imipramine. Effects of CRF on schedule-controlled responding were, however, antagonized by the administration of chlordiazepoxide and pentobarbital but not by buspirone, suggesting that CRF interacts with the GABA/benzodiazepine receptor mechanism complex but not with those systems involved in mediating the effects of buspirone. These results suggest that CRF interacts in significant ways with specific neurotransmitter systems subserving depression and anxiety.

In situ nucleoprotein structure involving origin-proximal SV40 DNA control elements

Nucleoprotein structures at the SV40 GC-box and adjacent AT-rich region have been probed by nucleases in permeabilized cells at nucleotide level resolution. The patterns of nuclease protection and hypersensitivity in these permeabilized cells that allow initiation of RNA and DNA synthesis are quite different from those observed in isolated nuclei that are inactive. Whereas simple DNA protection by factors is found in nuclei, the pattern in permeabilized cells includes very strong nuclease hypersensitive sites. Their arrangement suggests that the region exists as a higher order nucleoprotein complex in vivo, which is disturbed during the preparation of nuclei. The pattern is also found to be disturbed in permeabilized cells when T-antigen is inactivated by temperature-sensitive mutation. Since T-antigen origin binding sites and the GC-box region have been shown previously to interact functionally, the existence of a higher order structure involving both components provides a likely physical basis for the functional interaction of separate control elements.

Intra-cellular electrolyte changes and levels of endogenous digoxin-like substance within the plasma in patients with congestive heart failure

In this study, the lymphocytes and erythrocytes from peripheral venous blood were used as the study model from which were measured the cellular contents of potassium, sodium, calcium and magnesium in 50 patients with chronic congestive heart failure and 39 control patients. Levels of endogenous digoxin-like substance in the plasma and activities of Na/K ATPase in red cell membrane wer monitored simultaneously. In the patients with heart failure, the intracellular contents of potassium and magnesium were decreased while those of sodium and calcium were increased significantly. The levels of endogenous digoxin-like substance were much higher in the plasma than those either in healthy controls or in patients with heart disease but without congestive failure (273.7 +/- 35.5 vs 23.3 +/- 2.2 and vs 32.9 +/- 3.6 pg/ml, respectively, P less than 0.001 for both). The activities of Na/K-ATPase were much lower in the patients with heart failure than in the controls. Values for intracellular electrolytes were significantly correlated with the rising levels of digoxin-like substance in the plasma. Non-digitalis inotropic therapy was associated with the recovery of these alterations of heart function, with the levels of the digoxin-like substance decreasing and activity of Na/K-ATPase going up. We conclude that endogenous digoxin-like substance might play a role in the imbalance of intra-cellular electrolytes seen in patients with congestive heart failure. Digoxin may exacerbate the loss of intracellular potassium.

[Diterpenoid constituents in bulbs of Fritillaria anhuiensis S.C. Chen et S.F. Yin]

The bulb of Fritillaria anhuiensis, a substitute for the traditional Chinese medicine Beimu, has been used as antibechic and expectorant. From the either soluble part of the bulb, four constituents were isolated and identified by spectral analysis (IR, MS, 1HNMR, 13CNMR) as beta-sitosterol, daucosterol, ent-kaur-15-en-17-ol and ent-kauran-16 beta, 17-diol.

[Establishment of hybridoma cell lines producing monoclonal antibodies against-p30 antigen]

BALB/c mice were immunized with the purified p30 antigen. SP2/0 myeloma cells and immune spleen cells were fused with 50% PEG (Sigma, MW 3,350-4,000). The cell fusion rate was 93.95%, and the antibody producing rate 21.01%. The technique of limiting dilution was used for cloning of the hybridoma cells. Two hybridoma cell lines E8 and G1 secreting McAb against p30 antigen were obtained. The number of chromosome of both E8 and G1 cell lines was 98.7 +/- 6.54 and 97.7 +/- 7.77, respectively. Results of the PAGE of the ascites generated by the hybridoma cell lines E8 and G1 showed a thick protein band at the gamma-region which was absent from the ascites generated by the SP 2/0 myeloma cells. The immunoglobulin of the McAb E8 and G1 belonged to IgG2 subclass. The results of the immunohistochemical method using the horseradish peroxidase conjugated antibody showed that both E8 and G1 McAb only reacted with epithelial cells of the normal human prostatic glands and their ducts, but did not cross-react with other thirty-four different kinds of normal human tissues. The results of inhibiting ELISA test showed that both E8 and G1 McAb were only inhibited by the human seminal plasma and p30, weakly inhibited by the adult male's urine, but were not inhibited by other eight different kinds of human body fluids and secretions as well as semen from eight different species of animals. It was concluded that McAb of E8 and G1 were organ and species specific.(ABSTRACT TRUNCATED AT 250 WORDS)

[Anti-angina effect of puerarin and its effect on plasma thromboxane A2 and prostacyclin]

Plasma concentrations of thromboxane B2 (TXB2) and 6-keto-prostaglandin Fl alpha(6-K-PGFl alpha), the stable nonenzymatic metabolites of TXA2 and prostacyclin were assayed in 30 patients suffering from angina pectoris before and after administration of puerarin. In addition, serum lipids and HDL were also measured at the same time. 20 healthy subjects were chosen as the control group. Two weeks before and during administration of puerarin, aspirin, calcium-antagonists, all kinds of hypotensors and drugs relieving chest pain of angina pectoris were strictly prohibited. Puerarin was intravenously given, 500 mg daily for 7 days, which was considered as a therapeutic course. Besides relieving of chest pain, decreasing of heart rate and reduction of blood pressure clinically, it was also found that plasma 6-K-PGFl alpha concentrations were significantly elevated from 38.32 +/- 15.40 to 158. 79 +/- 98.62 pg (P less than 0.01) after administration of puerarin, but there was no significantly difference between plasma TXB2 concentrations before and after administering the drug. In addition, serum HDL was apparently enhanced as compared with that before the administration of puerarin (P less than 0.01). The results indicated that puerarin has the function of anti-angina, reducing both systolic and diastolic blood pressure and diminishing myocardial oxygen consumption.

Subtypes of HLA-A1 defined on the basis of CTL precursor frequencies

Recently we have shown that limiting dilution analysis can be used to detect cytotoxic T-cell precursor frequencies directed against individual HLA class I antigens. Using the same protocol, we have been able to define two subtypes of HLA-A1, which are indistinguishable by conventional typing sera as well as by cell-mediated lympholysis. One-dimensional isoelectric focusing analysis of the variants did not show any overall charge differences. However, family studies indicated that these HLA-A1 subtypes are genetically determined and can be distinguished on the bases of T-cell precursor frequencies in HLA-A1-negative blood donors.

[Magnetic resonance imaging in hypertrophic cardiomyopathy (preliminary experience of 6 cases)]

Preliminary experience of magnetic resonance imaging (MRI) in 6 cases of hypertrophic cardiomyopathy (HCM) is described in this article. MRI can provided pertinent pathoanatomic information of this entity and it is of definite value in the diagnostic evaluation of HCM. The relative value of different imaging techniques (such as echocardiography, CT and angiography, etc) in the diagnosis of HCM are also briefly discussed.

A model for urbanizing rural population and development measures: survey of a large specialized market in Xiliu town, Liaoning province

The authors present an urbanization model using the example of Xiliu town in Liaoning province, China. Xiliu has developed from a rural commune into a large-scale clothing market during the period since 1979. "The purpose...is to show, by means of a survey conducted in the town, the characteristics and formative factors of the model and to discuss the prospect of and measures for furthering this development."

[Immunohistochemical analysis of HLA class I antigens of the hepatocyte membrane in hepatitis B virus carriers]

HLA class I antigens on hepatocyte membrane were studied in liver biopsies from 46 patients with chronic hepatitis B virus infection by using immunoenzyme technique. The results revealed that the density of HLA class I antigens displayed on hepatocyte membrane in HBeAg positive carriers with minor hepatic inflammatory activity (the high replicative phase) was lower than that in patients with chronic active liver diseases (the low replicative phase) (P less than 0.005), but higher than that in patients with anti-HBe positivity and minor hepatic inflammatory activity (the nonreplicative phase) (P less than 0.05). In a follow-up of 21 HBeAg positive chronic HBV carriers, we found that five of the seven cases with high-density HLA class I antigens showed display of antigens on hepatocyte membrane, whereas only one of the 14 cases with lowdensity antigens were seroconverted from HBe antigen to antibody within one year. These findings suggest that the display on HLA class I antigens on hepatocyte membrane is enhanced and the cytotoxic T lymphacytes can recognize and lyze the infected hepatocytes.

In situ nucleoprotein structure at the SV40 major late promoter: melted and wrapped DNA flank the start site

New in situ probing methods have been developed and used to probe the nucleoprotein structures at the SV40 major late promoter in infected monkey cells. The region that contains the three proximal transcription elements was probed with DNase I and micrococcal nuclease in transcriptionally active, permeabilized cells, and with the single-strand selective reagent KMnO4 in intact cells. The downstream element is included in a region of enhanced DNase I reactivity at 10- to 11-bp intervals for approximately 140 bp, presumably because of DNA wrapping around a specifically positioned nucleosome particle. The two other proximal DNA elements appear to be mostly melted, with a protecting factor bound primarily to the template DNA strand. The protecting factor directly borders the wrapped particle. These observations provide an initial description of parts of the biological transcription machinery and suggest that the SV40 major late promoter elements are part of a higher order nucleoprotein complex that involves wrapped and melted DNA.

[Solvent extraction and high performance liquid chromatography with electrochemical detection for determination of plasma catecholamines]

This paper describes a technique for selectively extracting plasma catecholamines prior to quantification by HPLC-EC. The extraction system was a two-stage process. The first stage involve the complex formation between diphenylbrorate and catechol (diol) groups in alkaline medium. The second stage was a liquid-liquid extraction. The complex combined with tetraoctylammonium bromide to form an ion-pair formation into organic solvent. The catecholamines in turn was extracted with acid. This technique provided a very specific extraction procedure which resulted in chromatograms with few interfering compounds and gave absolute recoveries (100-103%) of norepinephrine, epinephrine and dopamine. Meanwhile, the plasma catecholamines were concentrated and the detective sensitivity was increased. A good linear relationship was found between the concentrations and ratio of peak heights of the catecholamines from 0.125-2 ng. The correlation coefficients ranged from 0.998-0.999. The coefficients of variation of the intra- and inter-assay were within 3 and 6% respectively. The results show that the procedure is very simple and fast. The method is valuable not only for clinical diagnosis but also for laboratory research.

Central neurotensin inhibits gastric acid secretion: an adrenergic mechanism in rats

Although parenteral neurotensin (NT) inhibits stimulated gastric acid secretion, published reports on the effect of centrally administered NT on gastric acid secretion are conflicting. This study provides evidence suggesting that, in chronic gastric fistula rats, intracerebroventricularly administered NT (15-60 micrograms) significantly reduces both basal and pentagastrin-, 2-deoxy-D-glucose-, and carbachol-but not histamine-stimulated gastric acid secretion. Using radioimmunoassay, the concentration of plasma immunoreactive NT increased from 30 to 200 pg/ml at 30 and 60 min, respectively after a single intracerebroventricular (i.c.v.) administration of NT at a dose of 60 micrograms. These serum NT concentrations can be reproduced by a constant NT i.v. infusion at 2 micrograms/kg.h. This parenteral infusion dose does not inhibit acid secretion as does i.c.v. NT. Pretreatment with the i.c.v. dopamine-2 receptor antagonists haloperidol or domperidone totally abolishes the inhibitory effect of i.c.v. NT on pentagastrin-stimulated gastric acid secretion. In contrast, pretreatment with the specific dopamine-1 receptor antagonist SCH 23900 or the specific dopamine-2 receptor antagonist sulpiride does not affect i.c.v. NT-induced inhibition of pentagastrin-stimulated gastric acid secretion. Pretreatment (intracerebroventricularly) with the alpha-adrenergic antagonist phentolamine blocks the antisecretory effect of i.c.v. NT. Administration of 3.0 micrograms NT per side directly into nucleus accumbens (NACB), using a stereotaxic technique, significantly reduces basal gastric acid secretion. This effect of central NT is blocked by pretreatment with intra-NACB haloperidol (0.5 microgram per side). These findings suggest that NT acts centrally to inhibit gastric acid secretion, an effect that may occur within NACB and be mediated by central nervous system alpha-adrenergic receptor activation.

Increase of donor-specific cytotoxic T lymphocyte precursors after transfusion

Cytotoxic T lymphocyte precursor (CTLp) frequencies were determined in the blood of 10 patients before and after transfusion. The male patients were selected from those on the waiting list for a heart or kidney transplantation, who had received no previous blood transfusions and had no panel-reactive antibodies. Both the limiting dilution curves obtained before as well as after transfusion were linear and applied to zero-order kinetics, indicating that only cytotoxic T cells were limiting in the assay. In 9 out of 10 patients CTLp frequencies against the blood donor antigens significantly increased (up to 107 times) compared to the CTLp frequencies measured before transplantation. The CTLp frequencies against controls, sharing no HLA antigens with the blood transfusion donor, were only slightly increased (up to 5 times) in 7 patients and decreased in 3.

[CT-guided fine needle aspiration biopsy of abdominal masses]

Fine needle aspiration biopsy were made under CT guidance of 50 cases of intra-abdominal masses, including liver in 37 cases, kidney in 6, pancreas and spleen in 1 respectively, and 5 biopsies were made of tumors of the abdominal cavity. The overall diagnostic accuracy was 92%, and the accuracy for malignancies was 84.6%. No complications occurred related to the procedure. The relevant factors for precise biopsy safety and the therapeutic value of this technique were discussed. It was concluded that CT-guided fine needle aspiration biopsy is precise in localization, it is a safe approach yielding satisfactory diagnostic accuracy.

[Effects of guan-fu base A on fast response action potentials of papillary muscles of guinea pigs]

Guan-fu base A is a new alkaloid first isolated from the tuber of Aconitum coreanum in China. The electrophysiological effects of guan-fu base A were examined on the isolated papillary muscles of guinea pigs by glass-microelectrode technique coupled with microcomputer real-time analysis. Guan-fu base A 50 micrograms/ml had less effect on RP, but markedly decreased Vmax and APA of the fast response action potentials. The action potential duration was shortened at all voltage levels and plateau height was lowered. ERP was prolonged relatively and activation voltage became more negative. The inhibition of guan-fu base A on Vmax showed frequency dependent effects. The above results suggested that guan-fu base A could block the fast Na+ channels and exhibited anti-arrhythmic action.

Acute and chronic effects of corticotropin-releasing factor on schedule-controlled responding and neurochemistry of pigeons

Key pecking by pigeons was maintained under various schedules of food presentation. Acute i.c.v. administration of corticotropin-releasing factor (CRF) (3.0-30.0 micrograms/kg) decreased responding in both components of a multiple 3-min fixed-interval, 30-response fixed-ratio schedule and under a multiple fixed-ratio schedule in which responding during one component was punished by shock delivery. The rate-decreasing effects of intermediate doses of CRF were blocked by the CRF antagonist alpha-helical CRF9-41 under the multiple fixed-internal fixed-ratio schedule, with 10.0 micrograms/kg of the antagonist producing a more complete reversal than 30.0 micrograms/kg. The rate-reducing effects of 10.0 and 30.0 micrograms/kg of CRF disappeared rapidly when CRF was administered daily, with complete restoration of responding occurring by the 4th day of chronic administration. Acute effects were recovered when CRF administration was discontinued for 7 to 14 days. Analyses of cerebrospinal fluid revealed that behaviorally active doses of CRF produced large, dose-dependent increases in levels of the serotonin metabolite 5-hydroxyindoleacetic acid and in the dopamine metabolites dihydroxyphenylacetic acid and homovanillic acid; smaller increases also occurred in the levels of 3-methoxy-4-hydroxyphenylethylene glycol, the metabolite of norepinephrine. Chronic administration of 30 micrograms/kg of CRF for a 4-day period did not reveal any change in metabolite levels when compared to those obtained after acute administration, with the exception of 3-methoxy-4-hydroxyphenylethylene glycol which approached control levels after chronic CRF. These results indicate that, as is the case with mammals, CRF has potent behavioral and neurochemical activity in avian species and that tolerance occurs rapidly to the behavioral effects.

[Cellular DNA content of human cervical carcinoma]

Microspectrophotometric measurement of the cellular DNA content of 73 cervical carcinoma specimens was carried out. The tumor was diploid in 7 cases, tetraploid in 2 and aneuploid in 64. The cases could be divided into hyperploid and hypoploid groups using the DNA index of 1.5 as demarcation. The DNA content was found to be closely related to the histologic types and mitotic figures of the tumors. Hyperploidy was more frequently seen in large-cell carcinoma and hypoploidy in small-cell varieties.

Generation of an antibody with a designed specificity difference for protein C and activated protein C

Rabbit polyclonal antibodies to a synthetic peptide, NH2-Asp-Thr-Asn-Gln-Val-Asp-Gln-Lys-Asp-Gln-Leu-Asp-Phe-Arg-CONH2 (A Pep), have been produced. This sequence is identical to that contained in the tetradecapeptide released from bovine protein C (PC) as a result of its conversion to its activated form (APC), except that Phe13 replaced the normal Pro13, in order to discourage cross-reactivity of antibodies to the carboxylterminal portion of APep with PC. The antibody pool obtained reacted with PC and showed virtually no cross-reactivity toward either APC or several typical plasma proteins. This general approach should serve well as a means of production of antibodies with a designed specificity capable of distinguishing between forms of the same protein that arise by release of peptide material.

Adhesive and degradative properties of human placental cytotrophoblast cells in vitro

Human fetal development depends on the embryo rapidly gaining access to the maternal circulation. The trophoblast cells that form the fetal portion of the human placenta have solved this problem by transiently exhibiting certain tumor-like properties. Thus, during early pregnancy fetal cytotrophoblast cells invade the uterus and its arterial network. This process peaks during the twelfth week of pregnancy and declines rapidly thereafter, suggesting that the highly specialized, invasive behavior of the cytotrophoblast cells is closely regulated. Since little is known about the actual mechanisms involved, we developed an isolation procedure for cytotrophoblasts from placentas of different gestational ages to study their adhesive and invasive properties in vitro. Cytotrophoblasts isolated from first, second, and third trimester human placentas were plated on the basement membrane-like extracellular matrix produced by the PF HR9 teratocarcinoma cell line. Cells from all trimesters expressed the calcium-dependent cell adhesion molecule cell-CAM 120/80 (E-cadherin) which, in the placenta, is specific for cytotrophoblasts. However, only the first trimester cytotrophoblast cells degraded the matrices on which they were cultured, leaving large gaps in the basement membrane substrates and releasing low molecular mass 3H-labeled matrix components into the medium. No similar degradative activity was observed when second or third trimester cytotrophoblast cells, first trimester human placental fibroblasts, or the human choriocarcinoma cell lines BeWo and JAR were cultured on radiolabeled matrices. To begin to understand the biochemical basis of this degradative behavior, the substrate gel technique was used to analyze the cell-associated and secreted proteinase activities expressed by early, mid, and late gestation cytotrophoblasts. Several gelatin-degrading proteinases were uniquely expressed by early gestation, invasive cytotrophoblasts, and all these activities could be abolished by inhibitors of metalloproteinases. By early second trimester, the time when cytotrophoblast invasion rapidly diminishes in vivo, the proteinase pattern of the cytotrophoblasts was identical to that of term, noninvasive cells. These results are the first evidence suggesting that specialized, temporally regulated metalloproteinases are involved in trophoblast invasion of the uterus. Since the cytotrophoblasts from first trimester and later gestation placentas maintain for several days the temporally regulated degradative behavior displayed in vivo, the short-term cytotrophoblast outgrowth culture system described here should be useful in studying some of the early events in human placen

Micrococcal nuclease as a probe for bound and distorted DNA in lac transcription and repression complexes

Micrococcal nuclease (MNase) is used to probe the structure of transcription and repression complexes at the lac regulatory region in vitro. Both the lac operator, 01, and the pseudo-operator, 03, are found to be protected from MNase digestion by the lac repressor on supercoiled DNA, and hypersensitive sites appear on both strands around nucleotide (nt) -26 between 01 and 03. This hyperreactive site is coincident with the site of the DNA kink shown previously to form within a loop caused by simultaneous repressor binding to 01 and 03. MNase hypersites are also observed both upstream from cAMP receptor protein (CRP) and downstream from bound RNA polymerase in open promoter complexes. In both open and closed complexes the binding of polymerase partially protects the backbone from MNase attack. Catabolite activator protein is shown to be required for both closed and open complex formation. Taken together with previous footprinting data, the results suggest that lac transcription complexes involve DNA bent towards a protein core consisting of RNA polymerase and catabolite activator protein.

Analysis of cytotoxic T cell precursor frequencies directed against individual HLA-A and -B alloantigens

We describe here a limiting dilution analysis to determine cytotoxic T lymphocyte precursor (CTLp) frequencies against individual HLA-A or -B antigens. This assay is reproducible and showed that the CTLp frequency of an individual remains stable with time. Significant variations in CTLp frequency against the same alloantigen were found in different individuals and even in monozygotic twins, showing that these differences were not (completely) genetically determined. Within an individual, a wide range of CTLp frequencies can be found against different allo-antigens. Serologically cross-reactivity seems not to interfere in this assay. This LDA is a practicable tool for a systematic analysis of CTLp response against selected individual HLA-A or -B antigens and can be used for the selection of HLA mismatched donors for transplantation patients.

Pathogenetic role of anti-vascular endothelial cell antibodies in systemic lupus erythematosus

In order to study the relationship between vascular endothelial cell (VEC) antigen system and systemic lupus erythematosus (SLE), including lupus nephritis, Terasaki's microcytotoxicity test and indirect immunofluorescence were used to detect anti-VEC antibody. VEC was identified by electron microscopy. Sera of 21 SLE patients and of 100 healthy donors were examined. Among the 21 SLE patients evaluated, 17 had kidney injury and 13 were in active stage SLE. Results showed that anti-VEC antibody was found in 76.2% of 21 SLE patients, while only 1% of the controls were positive (P less than 0.05). This antibody was detected in 84.6% of patients in active stage SLE and in 62.5% of patients in inactive stage (P greater than 0.05). In patients with and without kidney injury, it was detected in 82.4% and 50%, respectively (P greater than 0.05). These data show that anti-VEC antibody does exist in the sera of SLE patients, the presence of which is closely related to SLE onset and is independent of whether the patient is in active stage of SLE or has kidney injury. In summary, our data suggest that anti-VEC antibody may be one of the triggering factors in the vasculitis of SLE. It is proposed that renal VEC may act as a target cell which can be attacked by anti-VEC antibody to constitute an in-situ immune complex formation in the kidney, leading to lupus nephritis.

Benzodiazepine analogues L365,260 and L364,718 as gastrin and pancreatic CCK receptor antagonists

We examined the ability of the recently described 3-(benzoylamino)benzodiazepine analogue L365,260 and the 3-(acylamino)benzodiazepine analogue L364,718 to distinguish gastrin from pancreatic cholecystokinin (CCK) receptors. Neither L365,260 nor L364,718 when present alone (1 microM) caused stimulation of amylase release from guinea pig pancreatic acini or caused contraction of smooth muscle cells from guinea pig stomach. Each analogue inhibited CCK-stimulated amylase release, gastrin-17-I-stimulated smooth muscle contraction, binding of 125I-Bolton-Hunter-cholecystokinin octapeptide (125I-BH-CCK-8) to pancreatic CCK receptors, and binding of 125I-gastrin-17-I to gastrin receptors on pancreatic acini. L365,260, (Ki, 7.3 +/- 0.8 nM) was 50-70 times more potent than L364,718 at inhibiting binding of 125I-gastrin to pancreatic acini or gastrin-stimulated smooth muscle contraction. In contrast, L364,718 (Ki, 4 +/- 1 nM) was 145-200 times more potent than L365,260 at inhibiting binding of 125I-BH-CCK-8 to pancreatic acini or CCK-stimulated amylase release. Neither L364,718 nor L365,260 distinguished between high- and low-affinity CCK binding sites. L365,260 and L364,718 did not inhibit binding of radiolabeled vasoactive intestinal peptide, secretin, bombesin, substance P, or N-methylscopolamine to pancreatic acini. These results demonstrate that, in contrast to other gastrin-CCK receptor antagonists described, L365,260 is a selective gastrin receptor antagonist having an 80-fold higher affinity for gastrin than pancreatic CCK receptor, whereas L364,718 has a 125-fold higher affinity for pancreatic CCK receptors. Because of the selectivity of these two antagonists the involvement of CCK and gastrin in various physiological processes can be differentiated even when both receptors occur on the same cell.