The cannabinoid agonist Win55,212-2 inhibits calcium channels by receptor-mediated and direct pathways in cultured rat hippocampal neurons

The effects of the cannabinoid receptor agonist Win55,212 on Ca2+ channels were studied in rat hippocampal neurons grown in primary culture. Win55,212-2 inhibited whole-cell Ba2+ currents through Ca2+ channels by both CB1 receptor-mediated and direct mechanisms. The concentration dependent inhibition of the current showed two clear phases, a high-affinity receptor-mediated phase (IC50=14+/-2 nM) that was stereoselective and sensitive to a CB1 receptor antagonist, 300 nM SR141716, and a non-saturating phase that was neither stereoselective nor inhibited by SR141716. These concentration-dependent effects were paralleled by Win55212-induced inhibition of glutamatergic synaptic transmission. Win55,212-2 (100 nM) inhibited both omega-agatoxin IVA- and omega-conotoxin GVIA-sensitive currents. Thus, activation of cannabinoid receptors inhibits N- and P/Q-type Ca2+ channels. Activation of cannabinoid receptors inhibited only a fraction of the whole-cell Ca2+ channel current (17+/-2%) even though more than half of the whole-cell Ba2+ current was carried by N- and P/Q-type Ca2+ channels. Concentrations of agonist greater than 1 microM inhibited Ca2+ channels directly.

[Analysis of MDMA and its metabolites in urine by GC and GC/MS]

The purpose of this study is to investigate the metabolism of MDMA in the person and establish the methods for the determination of MDMA and its metabolites in urine. MDMA and its metabolite were isolated from urine by liquid-liquid extraction after acidic or enzymatic hydrolysis and were determined by GC/MS(EI, PCI) and GC/FID. The results showed that MDMA was metabolized to MDA and HMMA in man. MDA in the urine after MDMA administration was approximately 0.10-0.14 that of the parent drug. The sensitivity limits of methods were 2-50 ng/ml, and the recoveries were greater than 85%(CV < 10%). It is concluded that the methods were simple, quick and accurate for determining urine concentration of MDMA addicts. MDA/MDMA Ratio can be used to indicate whether the parent drug is taken alone or in combination with its active metabolite.

Molecular cloning and characterization of CDEP, a novel human protein containing the ezrin-like domain of the band 4.1 superfamily and the Dbl homology domain of Rho guanine nucleotide exchange factors

A cDNA for a novel human protein named CDEP was cloned using the subtractive hybridization method between dedifferentiated cartilage cells and overtly differentiated cartilage cells. CDEP cDNA contained an open reading frame encoding 1,045 amino acids in a total length of 3.4 kb. The deduced amino acid sequence revealed that a single polypeptide contained the ezrin-like domain, which is found in cytoskeleton-associated proteins of the band 4.1 superfamily, and the Dbl homology (DH) and pleckstrin homology (PH) domains, which are conserved in the Rho GEF (guanine nucleotide exchange factor) family. Northern blot analysis demonstrated that CDEP mRNA was expressed not only in the differentiated chondrocytes but also in various fetal and adult tissues. Since members of the band 4.1 superfamily and the Rho GEF family are crucial for microfilament organization, the novel protein CDEP may be involved in the adhesion, proliferation, and differentiation of some cell types including chondrocytes via changes in the cytoskeleton.

Sequence-specific and phosphorylation-dependent proline isomerization: a potential mitotic regulatory mechanism

Pin1 is an essential and conserved mitotic peptidyl-prolyl isomerase (PPIase) that is distinct from members of two other families of conventional PPIases, cyclophilins and FKBPs (FK-506 binding proteins). In response to their phosphorylation during mitosis, Pin1 binds and regulates members of a highly conserved set of proteins that overlaps with antigens recognized by the mitosis-specific monoclonal antibody MPM-2. Pin1 is here shown to be a phosphorylation-dependent PPIase that specifically recognizes the phosphoserine-proline or phosphothreonine-proline bonds present in mitotic phosphoproteins. Both Pin1 and MPM-2 selected similar phosphorylated serine-proline-containing peptides, providing the basis for the specific interaction between Pin1 and MPM-2 antigens. Pin1 preferentially isomerized proline residues preceded by phosphorylated serine or threonine with up to 1300-fold selectivity compared with unphosphorylated peptides. Pin1 may thus regulate mitotic progression by catalyzing sequence-specific and phosphorylation-dependent proline isomerization.

Characterization and cell cycle regulation of the related human telomeric proteins Pin2 and TRF1 suggest a role in mitosis

Telomeres are essential for preserving chromosome integrity during the cell cycle and have been specifically implicated in mitotic progression, but little is known about the signaling molecule(s) involved. The human telomeric repeat binding factor protein (TRF1) is shown to be important in regulating telomere length. However, nothing is known about its function and regulation during the cell cycle. The sequence of PIN2, one of three human genes (PIN1-3) we previously cloned whose products interact with the Aspergillus NIMA cell cycle regulatory protein kinase, reveals that it encodes a protein that is identical in sequence to TRF1 apart from an internal deletion of 20 amino acids; Pin2 and TRF1 may be derived from the same gene, PIN2/TRF1. However, in the cell Pin2 was found to be the major expressed product and to form homo- and heterodimers with TRF1; both dimers were localized at telomeres. Pin2 directly bound the human telomeric repeat DNA in vitro, and was localized to all telomeres uniformly in telomerase-positive cells. In contrast, in several cell lines that contain barely detectable telomerase activity, Pin2 was highly concentrated at only a few telomeres. Interestingly, the protein level of Pin2 was highly regulated during the cell cycle, being strikingly increased in G2+M and decreased in G1 cells. Moreover, overexpression of Pin2 resulted in an accumulation of HeLa cells in G2+M. These results indicate that Pin2 is the major human telomeric protein and is highly regulated during the cell cycle, with a possible role in mitosis. The results also suggest that Pin2/TRF1 may connect mitotic control to the telomere regulatory machinery whose deregulation has been implicated in cancer and aging.

Significance of proliferating cell nuclear antigen expression in liver metastasis of colorectal cancer

PURPOSE

The study contained herein was aimed at finding some possible pathologic factors that have significance for the prediction of liver metastasis in colorectal cancer.

METHOD

Resected specimens of colorectal cancer from 23 patients with liver metastasis and 30 patients without liver metastasis were subjected to pathologic study, including microscopic characteristics and proliferating cell nuclear antigen immunohistochemistry assay.

RESULTS

Strongly positive expression of proliferating cell nuclear antigen was present in 65.21 percent (15/23) of the liver metastasis group, whereas it was found in only 20 percent (6/30) of the group without liver metastasis (P < 0.005). Deeper invasion to the muscularis propria or serosa and less infiltration of lymphocytes surrounding the tumor were more frequently found in the liver metastasis group than in the other group (P < 0.025).

CONCLUSION

Extent of proliferating cell nuclear antigen expression, depth of invasion, and reaction of lymphocyte infiltration of the primary tumor could have predictive significance of colorectal cancer in liver metastasis.

Molecular characterization of the novel basic helix-loop-helix protein DEC1 expressed in differentiated human embryo chondrocytes

The differentiation of human embryo chondrocytes was markedly induced by the addition of Bt2cAMP to the culture medium. Using this culture system, a novel human cDNA for a basic helix-loop-helix (bHLH) protein (named DEC1) expressed primarily in the chondrocytes in response to Bt2cAMP was cloned by the subtractive hybridization method. DEC1 protein consists of 412 amino acids and exhibits structural similarities to the mammalian HES family, Drosophila hairy, and Enhancer of split m7 in the bHLH region. Northern blot analysis showed that DEC1 mRNA was expressed in various tissues including the cartilage, lung, spleen, and intestine, but not in the brain. These findings suggest that the bHLH factor DEC is involved in the control of cell differentiation in several tissues including cartilage.

Characterization of a cartilage-derived 66-kDa protein (RGD-CAP/beta ig-h3) that binds to collagen

A 66-kDa collagen fiber-associated protein (RGD-CAP) was isolated from a fiber-rich fraction of pig cartilage by ultrafiltration and collagen-affinity chromatography. Amino acid sequencing and cDNA cloning indicated that the RGD-CAP is identical or closely related to beta ig-h3 protein which is induced in human adenocarcinoma cells by transforming growth factor-beta (TGF-beta) (Skonier, J., Neubauer, M., Madisen, L., Bennett, K., Plowman, G.D., and Purchio, A.F. (1992) DNA Cell. Biol. 11, 511-522). The RGD-CAP, as well as beta ig-h3, has the RGD sequence in the C-terminal region. The native RGD-CAP bound to type I, II, and IV collagens even in the presence of 1 M NaCl. A recombinant preparation of RGD-CAP expressed in Escherichia coli cells also bound to collagen but not to gelatin. The RGD-CAP mRNA was expressed in chondrocytes throughout all stages, although the expression level was highest during the prehypertrophic stage. In addition, TGF-beta increased the RGD-CAP mRNA level in chondrocyte cultures. Since RGD-CAP transcripts were found in most tissues, this novel collagen-binding protein may play an important role in cell-collagen interactions in various tissues including developing cartilage.

Osteopontin is associated with bioprosthetic heart valve calcification in humans

Calcification of non-osseous tissues such as heart valves or vessels is a major concern in clinical practice. The exact mechanism is still unknown. Numerous studies have shown that mineral deposits of crystalline hydroxyapatite within these tissues were associated with increased non-collagenous protein content. More recently osteopontin was found to be associated with calcification in living tissues such as vessels and native human aortic valves. The aim of this study was to determine whether or not non-collagenous proteins can also be found in non-living tissues such as glutaraldehyde-pretreated porcine valves after implantation in humans. Thirty-eight glutaraldehyde pretreated porcine bioprostheses were studied: 16 not implanted and 22 after 11 years of implantation in the aortic and mitral valve position in humans. In areas of calcification vizualized by Von Kossa staining and microradiography, immunostaining using polyclonal antibodies against calcium-binding proteins showed osteopontin positive staining and no staining for osteocalcin, bone sialoprotein or osteonectin. In uncalcified areas and in non-implanted values, staining for osteopontin or other calcium-binding proteins was negative. Western blot analysis of macroscopically calcified and uncalcified areas showed that several proteins were adsorbed in implanted values and confirmed the presence of osteopontin in the calcified areas, while no immunolabelling was found in non-calcified areas, in uncalcified valves and in non-implanted valves. Thus the presence of osteopontin in the calcified areas of bioprosthetic heart valves implanted in human indicates that this protein is associated with bioprosthetic valvular calcification. Since these values are made of non-living connective tissue, and no cell immunostained for osteopontin was found around the calcified area, this suggests that a non-cellular mediated mechanism involving protein adsorption may play a role in bioprosthetic valvular calcification.

Long-term in vitro culture and characterisation of avian embryonic stem cells with multiple morphogenetic potentialities

Petitte, J.N., Clarck, M.E., Verrinder Gibbins, A. M. and R. J. Etches (1990; Development 108, 185–189) demonstrated that chicken early blastoderm contains cells able to contribute to both somatic and germinal tissue when injected into a recipient embryo. However, these cells were neither identified nor maintained in vitro. Here, we show that chicken early blastoderm contains cells characterised as putative avian embryonic stem (ES) cells that can be maintained in vitro for long-term culture. These cells exhibit features similar to those of murine ES cells such as typical morphology, strong reactivity toward specific antibodies, cytokine-dependent extended proliferation and high telomerase activity. These cells also present high capacities to differentiate in vitro into various cell types including cells from ectodermic, mesodermic and endodermic lineages. Production of chimeras after injection of the cultivated cells reinforced the view that our culture system maintains in vitro some avian putative ES cells.

Cannabinoid receptor agonists inhibit glutamatergic synaptic transmission in rat hippocampal cultures

Activation of cannabinoid receptors inhibits voltage-gated Ca2+ channels and activates K+ channels, reminiscent of other G-protein-coupled signaling pathways that produce presynaptic inhibition. We tested cannabinoid receptor agonists for effects on excitatory neurotransmission between cultured rat hippocampal neurons. Reducing the extracellular Mg2+ concentration to 0.1 mM elicited repetitive, transient increases in intracellular Ca2+ concentration ([Ca2+]i spikes) that resulted from bursts of action potentials, as measured by combined whole-cell current clamp and indo-1-based microfluorimetry. Pharmacological characterization indicated that the [Ca2+]i spikes required glutamatergic synaptic transmission. Cannabinoid receptor ligands inhibited stereoselectively the frequency of [Ca2+]i spiking in the rank order of potency: CP 54,939 > CP 55,940 > Win 55,212-2 > anandamide, with EC50 values of 0.36, 1.2, 2.7, and 71 nM, respectively. CP 55,940 was potent, but not efficacious, and reversed the inhibition produced by Win 55,212-2, indicating that it is a partial agonist. Inhibition of [Ca2+]i spiking by Win 55,212-2 was prevented by treatment of cultures with active, but not heat-treated, pertussis toxin. Win 55,212-2 (100 nM) inhibited stereoselectively CNQX-sensitive excitatory postsynaptic currents (EPSCs) elicited by presynaptic stimulation with an extracellular electrode, but did not affect the presynaptic action potential or currents elicited by direct application of kainate. Consistent with a presynaptic site of action, Win 55,212-2 increased both the number of response failures and the coefficient of variation of the evoked EPSCs. In contrast, cannabimimetics did not affect bicuculline-sensitive inhibitory postsynaptic currents. Thus, activation of cannabinoid receptors inhibits the presynaptic release of glutamate via an inhibitory G-protein.

Proteins and bioprosthetic calcification in the rat model

BACKGROUND AND AIM OF THE STUDY

The mechanism of valvular bioprostheses calcification is still unknown, but early studies showed increased Gla-protein content in calcified valves. Using an experimental model, which reproduces the clinical process, we therefore analyzed the role of minerals and proteins in bioprosthetic valvular calcification.

METHODS

Glutaraldehyde pretreated porcine valves were studied before and after implantation in rats by X-ray, calcium (Ca) and phosphorus (P) measurement, Fourier Transform Infrared (FTIR) spectroscopy, SDS-PAGE and 45Ca ligand blotting of the extracted proteins.

RESULTS

Before implantation, there was no X-ray calcification with very little Ca and P content. After implantation, X-ray calcifications appeared on day seven with increased Ca and P up to day 35 (p < 0.05, ANOVA). FTIR revealed structural proteins alone before implantation, plus minor proportions of lipids on day two, which always preceded Ca and P appearance. Ca and P increased up to day 35, first as amorphous and changed in carbapatite over time. SDS-PAGE before implantation revealed two proteins (66-kD and 54-kD) alone, which were sustained up to day 35. The 66-kD had 45Ca affinity. On day two, many other proteins appeared on SDS-PAGE, four of which (52, 45, 14 and below 14-kD) with 45Ca affinity. Protein pattern did not change from day two to 35.

CONCLUSIONS

Valvular bioprosthesis calcification is associated with progressive increase in Ca and P content and at least five calcium-binding proteins: one intrinsic valvular protein, pre-existing to implantation, plus four other, extrinsic valvular proteins adsorbed within the tissue after implantation.

[Concentrations and size distributions of aerosols in middle summer of Chengdu]

Statistical concentrations and size distributions of aerosols in middle summer of Chengdu city were measured by using optical scattering method. The influence of climate and its daily change affects on the concentration and distribution were analysed. The results showed: many of the distributions agreed with the Junge distribution; the peak concentration appeared near the noon; the relative humidity had strong influence on concentration; the clean-up effect of rain fall was evident. The measured results are useful for evaluating the environmental sanitation of the city.

Calcium mitigation in bioprosthetic tissues by iron pretreatment: the challenge of iron leaching

Preliminary studies in our laboratory have shown that iron pretreatment of glutaraldehyde-preserved tissues inhibited calcification. The present study was designed to further investigate this finding and to optimize the technique. Porcine valve tissue and bovine pericardium preserved in glutaraldehyde and pretreated by iron at different concentrations and incubation times were implanted either subcutaneously in rats or as a mitral valve substitute in sheep. Compared with control groups, calcification was markedly inhibited in the groups pretreated with Fe3+. There was a direct correlation between the degree of calcification and the iron content within the tissue. A minimal iron content within the tissue of 0.5% for porcine valve tissue and 0.2% for pericardial tissue was found to be necessary for calcium mitigation. A progressive leaching of Fe3+ was observed that could be stabilized by using a higher concentration of iron in the solution and or by additional pretreatment in glutaraldehyde at high temperature, but only for subcutaneously implanted tissues. By contrast, leaching was faster and more complete in the iron-pretreated tissue valves placed in the circulating blood environment, therefore resulting in calcified valves. Pretreatment in glutaraldehyde at high temperature (50 degrees C) alone was able to mitigate calcification in both subcutaneous and circulating blood environments, a new finding that may lead to an improved method for glutaraldehyde preservation of tissues.

Do donor or recipient species influence calcification of bioprosthetic tissues?

To determine whether donor or recipient species influence calcification of bioprosthetic tissues, glutaraldehyde-treated valvar or pericardial specimens from different species (calf, sheep, pig) were subcutaneously implanted in different animals (rat, rabbit, cow, hen). Significant differences in the rate of calcification of the implanted specimens were found, which have important practical and theoretical implications for the development of valvular bioprostheses.

Helicobacter pylori-associated gastritis and gastric carcinoma in Beijing

A retrospective study was performed on 500 consecutive gastric biopsies obtained from patients with a diagnosis of gastritis and gastric carcinoma. Overall, Helicobacter pylori was detected in 336 cases (67.2%); it was seen in 82.4% of patients with duodenal ulcer, 80.1% of patients with gastric ulcer, 76.1% of patients with chronic atrophic gastritis, 60.3% of patients with chronic superficial gastritis, and 32.1% of patients with gastric carcinoma. The gastric epithelium colonized by Helicobacter pylori showed characteristic changes including loss of the apical mucous portion of individual cells, dropout of epithelial cells, and erosions. There is a strong suggestion that the inflammation associated with Helicobacter pylori infection plays a role in the pathogenesis of gastric carcinoma.

Examination of DNA methylation of chromosomal hot spots associated with breast cancer

Widespread hypomethylation of DNA and regional hypermethylation, including tumor suppressor regions, have been demonstrated in several human cancers. Since a highly heterogeneous array of genetic anomalies have been associated with breast cancer, we examined several chromosomal hot spots for abnormal methylation patterns. Low-levels of increased methylation of HRAS (11p15) were observed between normal and tumor breast tissue samples from 8 patients. No noticeable variation in methylation was observed with DNA probes from chromosomes 11p15, 1p36, 17q22, 17p13.3 and 3p21 for the 7 ductal breast carcinoma patients, though some variability was observed for a patient with atypical medullary carcinoma. Additionally, the methylation pattern of the estrogen-receptor gene (6q24-27), whose protein product is increased in numerous breast cancers, also did not change. Therefore, as opposed to other cancer types, widespread hypomethylation and regional hypermethylation do not appear to be involved in the early stages of breast cancer and does not account for the molecular heterogeneity of the disease. Proposed alternative mechanisms for the diversity of genetic alterations associated with breast cancer are discussed.

Assay for recombinant and native human intraacrosomal antigen SP-10

PROBLEM

To develop a method to measure a recombinant sperm protein, SP-10, during scale up and purification for a contraceptive vaccine formulation.

METHOD

A quantitative assay method for the human intraacrosomal protein SP-10 was developed utilizing the format of indirect capture enzyme-linked immunosorbent assay (ELISA). A SP-10 specific monoclonal antibody mAb, MHS-10, was used as the capture antibody. Two recognition reagents, a rabbit polyclonal anti-SP-10 antisera (pAb) and a biotin-labeled mAb, MHS-10, were used as the recognition antibodies, respectively. A SP-10 recombinant fusion protein consisting of 125 SP-10 amino acids linked to glutathione transferase was used as a working SP-10 standard. The coefficient of variance for the assay system using the rabbit pAb was in the range of 0.099 to 0.157, and for the assay system using the biotinylated mAb MHS-10 was in the range of 0.081 to 0.084.

RESULTS

Employing biotinylated MHS-10 as the recognition antibody, it was found that the native SP-10 molecule had more than one MHS-10 epitope. The concentration of SP-10 in a pool of human sperm extracts was found to be approximately 1% of the total proteins, assayed by both of the recognition antibody systems.

CONCLUSIONS

The assay system described is useful to monitor the yield of recombinant SP-10 during scale-up production of the SP-10 vaccine.

[Phosphocalcium metabolism in patients with calcified valvular bioprosthesis]

Calcium and gla-protein content are increased in the calcifications of cardiac bioprostheses. Such calcifications are more frequent during growth, pregnancy and renal failure when bone gla-protein levels are elevated. We investigated whether bone gla-protein and other markers of calcium metabolism play a role in bioprostheses calcifications. Forty-seven patients were separated into 2 groups according to the presence (group A, n = 9) or absence (group B, n = 38) of bioprostheses calcifications, as assessed by echo-doppler and surgery. Plasma levels of calcium, phosphorus, magnesium, creatinine and alkaline phosphatases were measured by standard laboratory methods, parathormone and those of bone gla-protein by specific radioimmunoassays. Results (mean +/- SEM) were compared (group A versus group B, P < 0.01) using Student's test and one-factor variance analysis (ANOVA). Age was similar in both group (53 +/- 12.9 vs 50 +/- 12.3 yrs), whereas duration of implant was greater in group A (104 +/- 12.4 vs 66 +/- 6.5 months, P < 0.01). No statistically significant difference was found between group A and B concerning biochemical and/or hormonal markers of calcium metabolism. These negative results merit to be discussed, and further studies will be needed to explore the potential role of circulating bone gla-protein in bioprostheses calcifications.

Effects of copper coordinate complexes on the scavenging of reactive oxygen species

Effects of a 20-membered macrocyclic bicopper complex and dioxotetramine copper complexes with linear or cyclic structure on the scavenging of ROS have been studied by ESR. The results indicated that all three copper coordinate complexes have SOD mimetic activity. The dioxotetramine copper complex with linear or cyclic structure did not have the scavenging effect on .OH produced by H2O2-Fe++ and 1O2 produced by the H2O2-NaOCl system, but the 20-membered macrocyclic bicopper complex was found to be capable of depressing the intensity of the ESR spectrum of the adduct formed from TMP and 1O2 as well as making the spectrum of DMPO-OH adduct splittings. This fact may suggest that there are interactions between the ROS and 20-membered macrocyclic ring in the SOD mimic.

Analysis of mutations at the neurofibromatosis 1 (NF1) locus

A panel of 200 unrelated NF1 individuals has been screened for mutations using a panel of specific clones for the entire gene. DNA analysis on conventional Southern blots indicated that (20) 10% of NF1 patients showed aberrant bands. Small lesions involving nucleotide alterations were detected in a further 10 patients; 5 of these alterations have been fully characterised and are the novel mutations in the NF1 gene. A number of mutations were identified in exon 2. Identical mutations in this exon in two unrelated individuals involved an insertion of cytosine into codon 5662 and resulted in an inappropriate stop codon. This mutation also created a new MnlI site. Another novel mutation in exon 2 resulted from the insertion of thymidine at nucleotide 5678, which also created an inappropriate stop codon. We have so far completed the screen of exons 1-9 of the NF1 gene for the identification of mutations and have found no evidence of clustering of such mutations in the gene.

The inhibitory effects of 21 mimics of superoxide dismutase on luminol-mediated chemiluminescence emitted from PMA-stimulated polymorphonuclear leukocyte

Four groups comprising 21 superoxide dismutase (SOD) mimics synthesized by us were comparatively studied for their inhibitory effects on luminol-mediated chemiluminescence emitted from phorbol myristate acetate (PMA)-stimulated polymorphonuclear leukocyte (PMNL). Among these groups, 20-membered macrocyclic bicopper(II) complexes and 13-membered macrocyclic dioxotetramine copper(II) complexes exhibited relatively higher activities of scavenging reactive oxygen species (ROS) produced by PMA-stimulated PMNL as compared with polyamine Cu(II)-Zn(II) complexes and copper(II) complexes of bis-shiff-base. Moreover, distinctly different effects of SOD mimics in the biological system have been found even in the same group. It is suggested that the biological effects of some SOD mimics are related to their structures.

Inhibition by germanium oxide of the mutagenicity of cadmium chloride in various genotoxicity assays

The effects of germanium oxide on the genotoxicity of cadmium chloride were investigated. The incorporation of [3H]thymidine into testicular DNA was inhibited in mice injected ip with 1.35, 1.80 or 2.70 mg cadmium chloride/kg body weight. Germanium oxide (0.05 or 0.1 mg/kg body weight, sc) alone did not affect [3H]thymidine incorporation into testicular DNA but 0.05 mg germanium oxide/kg antagonized the inhibitory effect of 1.35 mg cadmium chloride/kg. However, combinations of the other doses of the two compounds did not show statistically significant antagonistic effects. Cadmium chloride significantly increased the frequencies of micronucleus formation in polychromatic erythrocytes, and of chromosome aberrations in the bone marrow of mice treated with 0.7, 1.4 or 2.7 mg/kg body weight, in a dose-related manner. These effects were inhibited by germanium oxide at doses of 0.1 or 0.5 mg/kg body weight, although germanium oxide alone did not affect micronucleus formation or the chromosome aberration rate. Cadmium chloride produced a dose-related increase in the frequency of sister chromatid exchanges in cultured human lymphocytes at concentrations of 5, 10 or 50 mumol. This effect was also inhibited by germanium oxide (0.05 or 0.1 mumol), although germanium oxide alone had no effect. There was a dose-related increase in the frequency of sperms with abnormal head morphologies from mice treated with 0.6, 1.1 or 2.2 mg cadmium chloride/kg body weight and this too was antagonized by the injection of germanium oxide (0.1 or 0.5 mg/kg body weight). Germanium oxide alone did not affect the frequency of sperm-head abnormalities.

Experimental study of the protective effect of intermittent hepatic pedicle clamping in the rat

The tolerance of the liver to ischaemia during intermittent clamping of the hepatic pedicle was compared with that during a continuous Pringle manoeuvre. Three groups of rats undergoing total durations of clamping of 60, 90 and 120 min were studied. A temporary peroperative portacaval shunt was used to exclude the effects of splanchnic venous stasis and allow independent study of the effects of hepatic ischaemia. In each group, three methods of portal clamping were evaluated: a continuous Pringle manoeuvre (n = 10), a 30-min intermittent clamping (n = 10) and a 15-min intermittent clamping (n = 10). The clamp release time between the periods of liver ischaemia was 5 min. Survival at day 7 and postoperative changes in liver function (transaminase enzymes, bilirubin, bromsulphthalein elimination, liver adenosine 5'-triphosphate levels) were recorded. Intermittent clamping of the pedicle was tolerated significantly better than continuous clamping. This method optimizes the ability of the liver to tolerate extended periods of ischaemia. For a given duration of ischaemia, no additional improvement could be produced by shortening the intermittent clamping period from 30 to 15 min. These data suggest that, when the Pringle manoeuvre is used, it should be applied intermittently rather than continuously.

A further study on capillary-like bile ductules proliferation in chronic active hepatitis

64 cases of chronic active hepatitis (CAH) and 84 cases of non-CAH liver diseases were studied with keratin stain. The capillary-like bile ductules (CLBD) were proliferating and their morphology was identical to that with Type V collagen stain reported before. CLBD proliferation were more marked in CAH than in other liver diseases, and it was considered to be one of the characteristics of CAH and could be used for differential diagnosis. The ultrastructure of CLBD was specific in morphology. The HBV-DNA in CLBD shown by the technique of in situ hybridization suggested that HBV might infect the cells of CLBD.

Plasma lipid and lipoprotein concentrations in Chinese males with coronary artery disease, with and without hypertension

Plasma lipid and lipoprotein concentrations were determined in 125 Chinese males with a medical history and electrocardiographic abnormalities consistent with the diagnosis of coronary artery disease (CAD). All subjects underwent coronary arteriography, and patients were divided into 3 groups based upon the results of the coronary arteriograms: 1) patients with a negative angiogram (CAD-, n = 30), without hypertension; 2) patients with a positive angiogram, without hypertension (CAD+, n = 70); and 3) patients with a positive angiogram, who had hypertension (CAD + HT, n = 25). Mean fasting plasma lipid and lipoprotein concentrations of these 3 groups of patients were compared to values in age and weight-matched groups of normal individuals (n = 80) and untreated patients with hypertension and no evidence of CAD (HT, n = 20). The results indicated that total plasma triglyceride, cholesterol, and LDL-cholesterol levels were significantly higher (P less than 0.001) than normal in patients with CAD+ and CAD + HT, whereas only plasma cholesterol levels were higher than normal in patients with HT. Although patients with CAD- had values intermediate between normal and CAD, the differences were not statistically significant. In addition, the ratio of LDL to HDL-cholesterol was significantly increased (P less than 0.05-0.001) above normal in patients with CAD+, CAD + HT, and HT. As before, the values in patients with CAD- were intermediate. These data document the presence of multiple abnormalities of lipid and lipoprotein concentration in patients with angiographic evidence of CAD, whether or not they were hypertensive. Furthermore, abnormalities in lipid and lipoprotein metabolism were seen in patients with hypertension alone.

Molecular diversity of HLA-DR4 haplotypes

Complementary DNA (cDNA) clones encoding beta chains of the DR and DQ regions and alpha chains of the DQ region were isolated and sequenced from four homozygous DR4 cell lines of different HLA-D types: GM3103(Dw4), FS(Dw10), BIN(Dw14), and KT3(Dw15). When compared with each other and with a previously published sequence from a DR4 (Dw13 cell line), the variability of DR beta 1 gene products is generally restricted to the region around amino acid position 70, with an additional polymorphism at position 86. Many of these differences, including an unusual amino acid substitution at position 57 in the Japanese cell line KT3(Dw15), may be due to gene conversion events from the DR beta 2 or DX beta genes. In contrast, DR beta 2 molecules are identical in Dw15, Dw10, and Dw4 cell lines. DQ beta chains isolated from GM3103(Dw4), FS(Dw10), and BIN40(Dw14) are also identical. However, the DQ beta sequence from cell line KT3(Dw15) differs substantially from all other previously reported DQ beta alleles, consistent with its serological designation, DQ "blank." The first domain sequences of DQ alpha chains were identical in all four cell lines. The data suggest that relatively circumscribed amino acid changes in the DR beta 1 molecule are responsible for the HLA-D typing differences between some haplotypes.

The effect of needle stimulation of acupuncture loci Tienshu (St-25) Chung-Wan (CV-12) on the immune response in sensitized mice against experimental cholera

The effects of stimulation of acupuncture loci from Tien-Shu (St-25) piercing through Chung-Wan (CV-12) on the Leukocytes and immune response were assessed in mice (that is, the anatomical equivalent of these loci of human acupuncture points). The leukocyte count increased and reached its highest level two hours after needling, then restored to normal level 24 hours later both in normal mice and immunized mice. Statistical analysis showed no significant variation on the lymphocyte/total leukocyte ratio in normal mice or immunized mice before, during and after needling. The effects of acupuncture on the production of anti-Vibrio cholerae in serum of the immunized mice can not be found, but produced positive effects in small intestine both on production of SIgA and antagonism to cholera. Furthermore these enhanced effects were higher by needling after oral (p.o.) boosting than that before oral boosting.

Immunosuppressive action of Qinghaosu

Qinghaosu, isolated and purified from the Chinese herb, Artemisia annua Linn, and identified as a sesquiterpene with a peroxide bridge and lactone structure, is a highly potent and non-toxic new antimalaria drug. This paper reports the immunosuppressive action of its water soluble derivative (hemisuccinate NA, QHS). The remarkable suppression by QHS of the in vitro 3HTdR incorporation by mitogen-stimulated mouse spleen cells and human peripheral lymphocytes, as well as the spontaneous incorporation by mouse thymocytes and blood cells from some leukemia patients is presented and its characteristics are described. The in vivo effect as shown by quantitative PFC is studied and the difference between the present in vitro and in vivo effects is investigated. The possible mechanism of inhibition and discrepancy in effects are discussed.

HLA-A, B and HLA-DR phenotypes in Mainland Chinese patients with diabetes mellitus

HLA-A, B and DR antigens were studied in Mainland Chinese diabetes mellitus patients and controls (31 Type I DM, 50 Type II DM, 105 controls). HLA-DR3 and HLA-A9 were increased in Type I diabetics only. An increase in HLA-DR4 was noted in Type I diabetics, but the increase was not statistically significant in this small series.