[Oral low-dose magnesium gluconate preventing pregnancy induced hypertension]

OBJECTIVE

To study the effects of oral low-dose magnesium gluconate in prevention of pregnancy induced hypertension (PIH) and its mechanism.

METHODS

A prospective randomized double-blind study was carried out in 51 pregnant women as treatment group (including 22 cases as treatment group 1 and 29 cases as treatment group 2) and 51 pregnant women as controls (including 28 cases as controls group 1 and 23 cases as control group 2). Low-dose magnesium gluconate (3 g/day) or placebo was given from the 28th week of gestation to delivery consecutively.

RESULTS

4% of the pregnant women developed PIH after magnesium gluconate treatment, which was substantially lower than that in the control group (16%) (P < 0.05). In the treatment group 2, women showed higher concentration of 6-keto-prostaglandin F1 alpha (PGF1a) and 6-keto-/thromboxane B2(TXB2) (P/T) ratio than that of the control group 2. Moreover, TXB2 level was lower than that in the control group 2. In the treatment group 1 women showed higher ratio of P/T than that of the control group 1. There were no significant differences of serum magnesium concentration among all groups.

CONCLUSION

Low-dose magnesium gluconate may efficiently prevent PIH in high risk women. The mechanism of action of magnesium gluconate probably involves to keep the balance of PGI2 and TXA2, but not associates with serum magnesium level.

Molecular Transport and SAPO-11 Crystal Growth in an i-Pr2NH-AlPO4-H3PO4-SiO2-H2O System

The crystal growth of SAPO-11 molecular sieve synthesized with i-Pr2NH as a novel template from mixtures of Si, Al, and P sources were studied by XRD, MAS-NMR, IR, and AAS techniques. It was found that the crystallization was improved partially by the desorption of i-Pr2NH from the crystallite products at high temperatures. The growth on (010) face was enhanced by stepwise adding external silica sol to the reaction mixtures during the synthesis process. The molecular transport and mechanism of the crystallization were discussed. Copyright 1997 Academic Press. Copyright 1997Academic Press

The involvement of serine 175 and alanine 185 of cytochrome b of Rhodobacter sphaeroides cytochrome bc1 complex in interaction with iron-sulfur protein

An approach involving cysteine replacement of potentially noncritical amino acid residues, followed by chemical modification studies, was used to investigate structure-function of the "cd helix" of cytochrome b from Rhodobacter sphaeroides. Three amino acid residues, Ser-155, Ser-175, and Ala-185, which span this region of cytochrome b, were selected for this study. The S155C substitution yields cells unable to support photosynthetic growth, indicating that Ser-155 is a critical amino acid residue. Further mutational studies of Ser-155 indicate that the size of the amino acid side chain at this position is critical for photosynthetic growth of R. sphaeroides. On the other hand, the S175C and A185C substitutions yield cells with photosynthetic growth rates and enzyme kinetics of the bc1 complexes very similar to those of the unmutated complex, indicating that Ser-175 and Ala-185 are noncritical residues. Thus, engineered cysteines at these two positions of cytochrome b are suitable for membrane topology and domain/subunit interaction studies. Cys-175 does not react with a sulfhydryl-modifying reagent, N-ethylmaleimide (NEM), either in sealed, inside-out chromatophores or in detergent-disrupted chromatophores, indicating that position 175 of cytochrome b is inaccessible from both sides of the membrane and is probably buried within the protein complex. Cys-185 reacts with NEM only after detergent disruption of the sealed, inside-out chromatophores, indicating that this position of cytochrome b is accessible on the outer (periplasmic) surface of the membrane. These results place the cd helix of cytochrome b on the periplasmic side of the chromatophore membrane. When purified A185C-substituted bc1 complex was treated with NEM, about 87% of the activity was abolished due to NEM modification of Cys-185. The signature of the Rieske iron-sulfur center is broadened upon NEM modification of A185C, with the gx signal shifting from g = 1.80 to g = 1.75, suggesting that Ala-185 of cytochrome b interacts with the iron-sulfur protein. When purified S175C-substituted bc1 complex is treated with NEM, no change in the activity is observed, since Cys-175 is inaccessible to NEM. However, when the iron-sulfur protein is removed from the S175C-substituted bc1 complex, Cys-175 becomes accessible to NEM, indicating that Ser-175 of cytochrome b is shielded by the iron-sulfur protein in the bc1 complex.

Modulation of multidrug resistance by three bisbenzyl-isoquinolines in comparison with verapamil

AIM

To compare cycleanine (Cyc), insularine (Insr), insulanoline (Insn) and verapamil (Ver) in modulation of multidrug resistance (MDR) in vitro.

METHODS

The cytotoxic effect was determined by 3-[4, 5-dimethylthiazol-2-yl], 5-diphenyl tetarzolium bromide (MTT) assay. The intracellular doxorubincin (Dox) accumulation was assayed by spectrofluorometer.

RESULTS

Cyc, Insr, Insn, and Ver showed significant activities in modulating Dox and vincristine resistances in acquired resistant MCF-7/Adr and KBv200 cell lines in a dose-dependent manner. Cyc, Insr, Insn, and Ver increased intracellular Dox accumulation in MCF-7/Adr cells. Cyc and Insr had greater activities than Ver in modulating MDR, while Insn had similar activity to that of Ver.

CONCLUSION

MDR was modulated by Cyc, Insr, and Insn, due to the increase of intracellular Dox accumulation.

[Water vapor permeability measurement of the materials used as a wound covering]

This paper introduces a new apparatus and method that suits to measuring the water vapor transmission rate (WVTR) of wound covering materials. WVTR of synthetic materials, amniotic membrane, porcine and cadaveric skin was measured under different conditions of four temperatures, three mediums, and "water cup" or "inverted water cup". The temperature was in close relationship with the WVTR except Omiderm, amniotic membrane, and cadaveric skin between 30 degrees C and 37 degrees C groups. The medium did not affect the WVTR (P > 0.05). There was significant difference between the "water cup" and "inverted water cup" groups(P < 0.01). This study suggests that the apparatus is easy-to-operate, reliable and suitable for the measurement of WVTR of burn wound coverings and other membranous materials.

[Comparison of the Chinese LJ strain structural gene with HM175, MBB, LA strains and the expression of hepatitis A virus antigen by LJ/HM175 recombinant vaccinia virus]

The nucleotide and amino acid sequences of a Chinese hepatitis A virus Long-Jia (LJ) strain were compared with that of HM175, MBB and LA strains in structural genes (nt 630-3049). The most extensive nucleotide homology was identified between LJ and MBB strains. The identity rates of nucleotide were 95.4%, 96.7% and 91.4%, respectively. Variation rates of amino acid were 0.91%, 0.91% and 2.98%, respectively. A total of 23 amino acid differences located in whole capsid region between LJ and LA strain, especially in VP1. Only 7 amino acid differences located in VP2 and VP3 between LJ and HM175/MBB strain. Restriction enzyme sites increased 10, 13 and 30 sites in 56 restriction enzymes tested, and decreases 15, 1 and 27 sites, respectively. BstE II (nt 2810) and Pvu I (nt 2013) were the peculiar sites of LJ strain. Hind III, Pst I and Sac I sites were identical among the four strains. After structural gene (nt 745-2993) of HM175 strain was replaced by LJ strain, the complete hepatitis A virus cDNA open reading frame was inserted into pJSA1175 (vaccinia virus expression vector) downstream of promoter 7.5 k. Hepatitis A virus antigen expressed was 1:16 in titer by sandwich ELISA. Band-patterns of anti-VP0, anti-VP1 and anti-VP1, 2, 3, were as same as that of HM175 strain and natural hepatitis A virus antigen by Western blot analysis.

Expression and regulation of steroid 5 alpha-reductase in the genital tubercle of the fetal rat

The genital tubercle is a bipotential anlage that can develop into a penis or a clitoris. Formation of the penis requires synthesis within the tubercle of the androgen dihydrotestosterone by steroid 5 alpha-reductase isozymes. Isozyme 1 mRNA and protein were present in epithelial cells, whereas isozyme 2 transcripts were present in mesenchymal cells of developing genital tubercles from day 17, 19, and 21 rat embryos. These expression patterns were observed in both uncommitted anlagen and in committed male or female structures. Androgens did not significantly influence levels of 5 alpha-reductase mRNAs or affect their cellular distributions. Together with genetic data, the results implicate the mesenchyme as the crucial cell type in formation of the male external genitalia.

[A comparative study on effect of two bisbenzylisoquinolines, tetrandrine and berbamine, on reversal of multidrug resistance]

A comparative study on the effect of two bisbenzylisoquinolines, tetrandrine (TTD) and berbamine (BBM), and verapamil (VRP) on reversing multidrug resistance was reported. TTD, BBM and VRP showed significant activity in reversing adriamycin (ADR) and vincristine (VCR) resistance in acquired resistant MCF-7/Adr and KBv200 cell lines, and the effect was shown to be dose-dependent. TTD, at the concentration of 10 mumol.L-1, completely reversed ADR resistance in MCF-7/adr cells. TTD, BBM and VRP increased intracellular ADR accumulation in MCF-7/adr cells. There is minor difference in structure between TTD and BBM. TTD showed greater activity than VRP in reversing MDR, while BBM showed similar activity to that of VRP. TTD also showed significant activity in vivo in reversing ADR resistance in MDR MCF-7/Adr solid tumor in nude mice.

Molecular characterization of two mammalian bHLH-PAS domain proteins selectively expressed in the central nervous system

Here we describe two mammalian transcription factors selectively expressed in the central nervous system. Both proteins, neuronal PAS domain protein (NPAS) 1 and NPAS2, are members of the basic helix-loop-helix-PAS family of transcription factors. cDNAs encoding mouse and human forms of NPAS1 and NPAS2 have been isolated and sequenced. RNA blotting assays demonstrated the selective presence of NPAS1 and NPAS2 mRNAs in brain and spinal cord tissues of adult mice. NPAS1 mRNA was first detected at embryonic day 15 of mouse development, shortly after early organogenesis of the brain. NPAS2 mRNA was first detected during early postnatal development of the mouse brain. In situ hybridization assays using brain tissue of postnatal mice revealed an exclusively neuronal pattern of expression for NPAS1 and NPAS2 mRNAs. The human NPAS1 gene was mapped to chromosome 19q13.2-q13.3, and the mouse Npas1 gene to chromosome 7 at 2 centimorgans. Similarly, the human NPAS2 gene was assigned to chromosome 2p11.2-2q13, and the mouse Npas2 gene to chromosome 1 at 21-22 centimorgans. The chromosomal regions to which human NPAS1 and NPAS2 map are syntenic with those containing the mouse Npas1 and Npas2 genes, indicating that the mouse and human genes are true homologs.

Endothelial PAS domain protein 1 (EPAS1), a transcription factor selectively expressed in endothelial cells

Here we describe the cloning and characterization of a PAS domain transcription factor termed endothelial PAS-1 (EPAS1). This protein shares 48% sequence identity with hypoxia inducible factor (HIF-1alpha) and lesser similarity with other members of the basic helix-loop-helix/PAS domain family of transcription factors. Like HIF-1alpha, EPAS1 binds to and activates transcription from a DNA element originally isolated from the erythropoietin gene and containing the sequence 5'-GCCCTACGTGCTGTCTCA-3'. Activation by both HIF-1alpha and EPAS1 is stimulated by hypoxic conditions. EPAS1 forms a heterodimeric complex with the aryl hydrocarbon nuclear transporter prior to transcriptional activation of target genes. EPAS1 expression is limited to the endothelium of mouse embryos and, in agreement with its cell type-specific expression pattern, is capable of specifically activating the transcription of the endothelial tyrosine kinase gene Tie-2. These observations raise the possibility that EPAS1 may represent an important regulator of vascularization, perhaps involving the regulation of endothelial cell gene expression in response to hypoxia.

A simple and quick method to evaluate the influence of food price policy on population-based nutrition status and related nutrition intervention

Food price policies have a major influence on population food choice and nutritional status, especially for low-income families. Therefore, simple and quick methods to evaluate their influence is desirable. Consistent with nutritional rationality and economical feasibility, a mathematical model was developed by Linear Programming to appraise the influence and rationality of the subsidization of egg and pork in Tianjin, using the data about food varieties and their prices in Tianjin in 1990. It was found that food subsidism to influence choice was not rational for improvement in nutritional status of low-income families. The concept, of "food choice space" was developed and its implications for nutrition intervention explored. The model developed can be used to judge the nutritional effect of food price policies and provide baseline data for nutrition intervention.

Gamma radiation effect on vascular smooth muscle cells in culture

PURPOSE

Prior work in our laboratory demonstrated that external gamma irradiation administered within 48 h following balloon catheter carotid artery injury in rats produced a marked inhibition of intimal hyperplasia and restenosis. The current study used smooth muscle cells (SMC) in vitro to examine the radiation dose response and to investigate the cellular mechanism by which radiation inhibits SMC proliferation.

METHODS AND MATERIALS

Quiescent rat aortic SMC in plasma were refed with whole blood serum to stimulate synchronous proliferation and immediately irradiated with single fraction doses of 1.25-20 Gy.

RESULTS

Comparison between a micronucleus assay and a clonogenic assay indicated a dose-dependent inhibition of SMC growth, with an ED50 at 2-3 Gy. The micronucleus assay also demonstrated a dose-dependent increase in apparent chromosomal damage at 72 h after irradiation. Inhibition of SMC growth by radiation did not correlate with changes in intracellular or released mitogenic activity. Furthermore, there was no evidence of apoptosis in irradiated SMC up to 96 h after treatment.

CONCLUSION

Radiation likely inhibits SMC proliferation after arterial injury by a dose-dependent mechanism of lethal and/or sublethal cellular injury leading to clonogenic cell death.

[A study of insulin sensitivity and its related factors in patients with non-insulin dependent diabetes mellitus and impaired glucose tolerance]

In order to evaluate insulin sensitivity and its related factors in abnormal glucose tolerance, 572 cases of non-insulin dependent diabetes mellitus (NIDDM), 647 cases of impaired glucose tolerance (IGT) and 543 normal controls were studied. The results showed that fasting insulin levels (FIns) and the prevalence of hyperinsulinemia were higher in NIDDM than that in IGT and higher in IGT than that in normal controls (P < 0.01). Insulin sensitivity index (ISI) [-ln(FInx x fasting blood glucose)] ranked from high to low in the order of normal controls, IGT subjects, newly-diagnosed NIDDM patients and patients with known NIDDM (P < 0.01). In each group ISI was smaller in obese subjects or patients than in non-obese ones. Mono-factor analysis demonstrated that ISI in each group was negatively related to body mass index (BMI) and positively related to high density lipoprotein (HDL)-cholesterol. ISI in NIDDM and IGT group was negatively related to blood pressure. Multiple analysis showed that the ISI had significantly negative correlation with BMI and some correlation with blood pressure and blood lipids. In conclusion, the patients with abnormal glucose tolerance had hyperinsulinemia and insulin resistance. ISI was related to some risk factors of vascular diseases.

[The effects of intensive DMPA regimen in the treatment of Graves' ophthalmopathy]

35 patients with Graves' ophthalmopathy were treated with DMPA regimen which included dexamethasone (D) 20-30 mg and Methotrexate (M) 15-20 mg i.v. once a week and prednisone (P) 20 mg/d p. o. 4 times a week for 4 weeks followed by addition of azathioprine (A) or 6-MP 75-100 mg/d and the increment of prednisone (20 mg/d) to 5 times a week in the fifth and sixth weeks. The full intensive course of therapy lasted for 6 weeks. If necessary, the similar course of therapy might be repeated. Later on, each patient was mintainted on a therapy with P and A or P and 6-MP for another 1-2 months then the P and A or P and 6-MP for another 1-2 months, and then the P and A or 6-MP were tapered and finally discontinued at the end of sixth month. The symptoms and signs of the opthalmopathy were evaluated blindedly at the beginning and the end of the first and second courses of the therapy by two ophthalmologists. The results showed that the symptoms and signs were significantly improved in 33 (94.3%) cases. A decrease of eyeball protrusion of 1.22 +/- 1.15 and 1.28 +/- 1.15 mm in the left and right eyes respectively was shown by eophthalmometry reading (both P < 0.0005, compared with before and after the therapy). The decrease of exophthalmos was more remarkable in the cases with ophthalmopathy for < or = 1 year than that > 1 year. 11/22 patients recovered their ability to close eyes adequately. The diplopia was corrected in 8/15 cases. The mobility of eye ball returned to normal in 5/15 cases. Exposed lesion and/or ulceration of the cornea found in 7 patients were cured. Serious side and/or toxic effects of the drugs were not present during the course of therapy. It is suggested that DMPA regimen is an effective, safe and cheap approach to the treatment of Graves' ophthalmopathy.

Study of the prevalence of diabetes mellitus in adults in the Shougang Corporation in Beijing

The aim was to determine the burden of diabetes mellitus (DM) in an urban area of China to aid us in planning preventive measures for those at risk of DM. A survey was conducted among the 29,859 subjects aged between 30 and 64 belonging to 32 units of the Shougang Corporation (a heavy industry enterprise) within the Beijing area. WHO study protocols and diagnostic criteria were used to determine the prevalence of DM and impaired glucose tolerance (IGT). The results showed that the age-adjusted prevalence of DM and impaired glucose tolerance (IGT) was 3.63% and 4.19%, respectively, both increasing with age. Peak prevalence for both occurred in the 60-64 age group. Prevalence showed no difference between the sexes in DM but was higher for females in IGT. Obesity, being overweight, a family history of diabetes mellitus and in women, a history of delivering babies with macrosomia, all correlated closely with the prevalence of DM and IGT. High protein intake was also associated with DM, Smoking had no effect on either DM or IGT. Intellectual workers had a higher incidence of IGT than manual workers. Seventy per cent DM was undiagnosed prior to the survey. This survey, done according to the recommendation of WHO, and including appropriate adjustments, reflects the growing prevalence of DM and IGT in this population. It can be compared with other studies for epidemiological analysis.

[Prevalence and risk factors of hypertension and coronary heart disease in the subjects with abnormal glucose metabolism]

The prevalence and risk factors of hypertension and coronary heart disease (CHD) in subjects with abnormal glucose metabolism (AGM) were studied in a population of 29,960 in the Capital Iron and Steel Corporation. The results showed that the prevalences of hypertension and CHD were 37.37% and 9.32% in diabetes group and 29.88% and 6.25% in impaired glucose tolerance group respectively. Both aging and obesity were the risk factors for AGM, hypertension and CHD. Hyperglycemia and hyperlipidemia were related to the occurrence of hypertension and CHD. Our results indicate that the prevalence of CHD and hypertension is significantly increased in AGM subjects, and they have many other risk factors of cardiovascular disease.

Multiple organ injuries and failures caused by shock and reperfusion after gunshot wounds

Experiments were performed to observe the changes of multiple system organ failure (MSOF) and gut barrier function caused by shock and reperfusion after gunshot wounds. Eighteen dogs were divided randomly into two groups. In the experimental group, the dogs were subjected to 60 minutes of shock (40mm Hg), followed by reinfusion of shed blood after hindlimb gunshot wounds. In the control group, the dogs experienced pure gunshot wounds without shock and reperfusion. The results showed that dogs in the experimental group developed multiple system organ injuries or failures compared with the control group. The levels of malondialdehyde (MDA) values in plasma were significantly elevated in the experimental group when compared with preinjury and the control group. Gut flora disorder, bacillus intestinalis overgrowth, and bacterial translocation occurred in the experimental group. The pathological results support the gut barrier function injury. The results indicated that pure gunshot wounds do not easily injure gut barrier function and produce MSOF. Gunshot wounds with shock and reperfusion are capable of causing gut flora disorder, bacillus intestinalis overgrowth, and lead to bacterial translocation, furthermore causing MSOF. Although fluid resuscitation is a potential treatment modality, pathogenically, it can lead to MSOF.

In vivo effects of tumor necrosis factor-alpha on incised wound and gunshot wound healing

Recombinant tumor necrosis factor alpha (TNF-alpha) was applied to incised wounds (adult rats, n = 14) and gunshot wounds (dogs, n = 5). The accumulation of RNA and DNA in regenerative tissue, the wound disruption strength (WDS), and histology were examined. The results showed that a single dose of TNF-alpha in saline with highly purified bovine serum albumin increased the WDS and accumulation of RNA and DNA in regenerative tissue in incised wounds 3 days after surgery (p < 0.05). Also, TNF-alpha promoted the inflammatory reaction in the wounded area of gunshot wounds. Histology revealed increased capillary tube-like structures and collagen formation and fibroblast proliferation in both incised and gunshot wounds treated with TNF-alpha. The results indicated that locally applied TNF-alpha benefited the incised and gunshot wound healing. These mitogenic and inflammatory effects of TNF-alpha may be the synergistic effects with other growth factors such as platelet-derived growth factor (PDGF).

[An experimental study on injury of intestinal immuno-barrier in rat after scald]

A dynamic observation on injury of intestinal immuno-barrier in scalded rat was performed to investigate the relationship between the injury of intestinal immuno-barrier and bacterial translocation. After 40% TBSA third degree scald, a decrease of IgA in intestinal content and the number of CD3+ and CD4+ T lymphocyte, and reduction of IgA coat rate of intestinal bacteria were observed. At the same time, an increase in the incidence of bacterial translocation was detected. The results indicated that intestinal immuno-barrier was damaged and its protective function was weakened after an extensive thermal injury, and it suggested that the injury of intestinal immuno-barrier might play an important role on the development of postburn bacterial translocation and postburn sepsis.

AIDS-associated infections in salivary glands: autopsy survey of 60 cases

We reviewed the autopsy findings for the submandibular glands of 60 patients with AIDS who were autopsied at the George Washington University Medical Center (Washington, DC) from 1982 to 1992. AIDS-associated infections in the submandibular glands were compared with those in the pancreas and lung. Cytomegalovirus intranuclear inclusions were found in 10 cases, and Pneumocystis carinii infection was found in one case. Disseminated mycobacterial and fungal infections were not identified in the submandibular gland, even in the presence of documented pancreatic and pulmonary infection (P < .05). Overall, the major salivary glands of patients with AIDS are less frequently involved with disseminated opportunistic infections than is either the lung or the pancreas (P < .01 and P < .001, respectively).

HIV envelope-directed signaling aberrancies and cell death of CD4+ T cells in the absence of TCR co-stimulation

HIV-1 infection in CD4(+) T cells initiates a viral cytopathic effect (CPE) that is dependent on the activation of intracellular protein tyrosine kinases (PTK). PTK in T cells are also activated during the course of TCR or CD4 receptor engagement and the manner of receptor engagement may generate signals leading either to cell proliferation, tolerance induction (anergy) or programmed cell death (PCD). We have identified PTK triggered during the interaction of cells stably expressing surface HIV envelope (gp 120/gp41; HIVenv) and CD4(+)T cells, which leads to extensive and rapid individual cell death. We have found that killing is accompanied by tyrosine phosphorylation and activation of the CD4-associated p56(ICK) kinase, and by activation of a second member of the scr family of PTK, p59(fyn) kinase, normally associated with T cell stimulation through the TCR. Interestingly, in contrast with normal T cell signaling, the zeta subunit of the TCR fails to become tyrosine-phosphorylated during signaling accompanying HIV-directed cell killing. Downstream activation of the ZAP-70 PTK also does not occur. Unlike T cell apoptosis triggered by soluble HIVenv glycoproteins, which requires co-stimulation of CD4 and the antigen-specific TCR, T cell killing by membrane-associated HIVenv does not require TCR co-stimulation, because aberrant signaling and cell death are triggered by CD4(+) but TCR- cell lines. These results are the first report where dual activation of the Lck and Fyn PTK does not result in normal downstream signaling through the ZAP PTK, We suggest by analogy to SCID resulting from ZAP-70 mutations, that the dissociation of upstream PTK activation from ZAP-70 signaling contributes to T cell depletion by HIV and to the development of AIDS.

Human immunodeficiency virus 1 envelope-initiated G2-phase programmed cell death

Despite intensive investigation, no clearly defined mechanism explaining human immunodeficiency virus (HIV)-induced cell killing has emerged. HIV-1 infection is initiated through a high-affinity interaction between the HIV-1 external envelope glycoprotein (gp120) and the CD4 receptor on T cells. Cell killing is a later event intimately linked by in vitro genetic analyses with the fusogenic properties of the HIV envelope glycoprotein gp120 and transmembrane glycoprotein gp41. In this report, we describe aberrancies in cell cycle regulatory proteins initiated by cell-cell contact between T cells expressing HIV-1 envelope glycoproteins and other T cells expressing CD4 receptors. Cells rapidly accumulate cyclin B protein and tyrosine-hyperphosphorylated p34cdc2 (cdk1) kinase, indicative of cell cycle arrest at G2 phase. Moreover, these cells continue to synthesize cyclin B protein, enlarge and display an abnormal ballooned morphology, and disappear from the cultures in a pattern previously described for cytotoxicity induced by DNA synthesis (S phase) inhibitors. Similar changes are observed in peripheral blood mononuclear cells infected in vitro with pathogenic primary isolates of HIV-1.

[Effects of SL-probiotic preparation on the body weight and phagocytosis of white mice]

Effects of SL-probiotic preparation on the body weight and the phagocytic functions in white mice were studied. Bioassay of its toxicity showed SL-P was non-toxic. Body weight of the treated mice increased significantly as compared with that of controls 10 days after treatment with SL-probiotic preparation. Phagocytic activity, acid phosphatase activity, lysozyme activity of the peritoneal macrophages of the tested mice were enhanced significantly as compared with those of normal controls. The same results were obtained with respect to serum lysozyme activity. These observations showed that SL-probiotic preparation could activate macrophage function in mice and hence enhancement of non-specific immunity.

Cardiologists' practices compared with practice guidelines: use of beta-blockade after acute myocardial infarction

OBJECTIVE

Our purpose was to measure cardiologists' level of adherence to guidelines for long-term use of beta-adrenergic blocker therapy after acute myocardial infarction.

BACKGROUND

Beta-blocker therapy after acute myocardial infarction has been shown to reduce the incidence of reinfarction and associated mortality. To learn about cardiologists' use of this therapy after hospital discharge and their level of adherence to American College of Cardiology guidelines, we analyzed insurance claims from 17 network-model health plans located throughout the United States.

METHODS

The study group included 150 cardiologists who had contracts with one of the health plans and their 280 patients who were plan members (excluding Medicare enrollees) and received inpatient treatment for acute myocardial infarction that did not include revascularization during 1992. These patients accounted for 307 separate hospital admissions. Insurance claims were used to measure beta-blocker usage and to identify possible contraindications.

RESULTS

Forty-three percent of the cases (131 of 307) involved apparent deviations from the guidelines: 11% of cases (35 of 307) involved possible errors of commission (beta-blocker given in the presence of a contraindication) and 31% (96 of 307) errors of omission (beta-blocker not given in the absence of a contraindication). Of the 185 patients who were eligible for the therapy (no contraindications), only 48% (89 of 185) were treated.

CONCLUSIONS

Cardiologists currently exhibit a low level of compliance with their specialty's guidelines for postinfarction beta-blockade. Slightly fewer than 50% of the study patients who were eligible for treatment actually received a beta-blocker after hospital discharge. This result, combined with the drug's known level of effectiveness in preventing recurrent myocardial infarction, suggests that increased use could avert approximately 1,900 deaths annually nationwide.

Auxin-binding protein 1 does not bind auxin within the endoplasmic reticulum despite this being the predominant subcellular location for this hormone receptor

Auxin-binding protein 1 (ABP1) is a unique hormone receptor because it resides primarily in the lumen of the endoplasmic reticulum (ER); however, two lines of evidence presented here suggest that ABP1 does not bind auxin within the endoplasmic reticulum, despite its predominant location there. First, ABP1 cannot be photolabeled in intact cells that have accumulated the auxin and photolabeling reagent 5-[7-3H]azidoindole-3-acetic acid, indicating either that auxin is excluded from the ER and is not available for photolabeling to ABP1 or that binding conditions within the ER lumen are insufficient for photolabeling. Second, at the pH of the ER lumen, auxin binding to ABP1 is not detectable. The pH estimate of the ER lumen is based on an indirect assay, which indicates that the pH is closer to pH 7 than to the binding optimum of pH 5.5. These results indicate that ABP1 does not bind auxin within the ER and point to a site of action that is post-ER. The effect of auxin on its trafficking from the ER was tested in an animal expression system. ABP1 expressed at high levels in COS7 cells is efficiently retained in the ER lumen and is not secreted even in the presence of 190 microM indole-3-acetic acid, an auxin concentration that is 40 times above the Kd for indole-3-acetic acid binding to ABP1.

Selection of novel exon recognition elements from a pool of random sequences

A 20-nucleotide sequence close to the 3' end of the internal exon of a model two-intron, three-exon pre-mRNA (DUP184 [Z. Dominski and R. Kole, J. Biol. Chem. 269:23590-23596, 1994]) was replaced by a random 20-mer, resulting in a pool of pre-mRNAs which, like the initial DUP184 construct, were spliced in vitro by a pathway leading to predominant skipping of the internal exon. The randomized pre-mRNAs were subjected to a selection protocol, resulting in a pool enriched in pre-mRNAs that efficiently included the internal exon. Isolation and sequencing of a number of clones corresponding to the selected pre-mRNAs showed that two classes of sequences were selected from the initial pool. Most abundant among these were sequences with purine tracts similar to those in the recently identified exon-splicing enhancers while a smaller class included sequences lacking discernible purine tracts within the 20-nucleotide region. Splicing of selected pre-mRNAs showed that the purine tracts vary in their ability to promote exon inclusion and, more important, that sequences lacking purine tracts stimulate inclusion of the internal exon as efficiently as their purine-rich counterparts. The latter result indicates the existence of a novel class of exon recognition sequences or splicing enhancers.

Expression and regulation of steroid 5 alpha-reductase in the urogenital tract of the fetal rat

Two androgens, testosterone and dihydrotestosterone, are required for the development of the male urogenital tract in the rat. Testosterone is secreted by the fetal testes and is thought to elicit differentiation of the Wolffian ducts into seminal vesicles, vas deferens, and epididymides. Testosterone is converted into dihydrotestosterone by steroid 5 alpha-reductase in the urogenital tract, and this conversion is necessary for the differentiation of the prostate and external genitalia. Genes encoding two 5 alpha-reductase isozymes, designated type 1 and type 2, have been identified. We examined the expression and regulation of these genes on days 17-21 in the urogenital tracts of male and female fetuses. Expression of the type 1 gene predominated in epithelial cells, whereas type 2 gene expression was limited to mesenchymal cells. Surprisingly, this expression pattern was detected in both testosterone-dependent and dihydrotestosterone-dependent anlagen of the urogenital tract and was the same in both male and female fetuses. Furthermore, transcripts encoding the two isozymes were present in their respective cell types before the overt differentiation of internal genitalia. Androgens stimulated expression of the type 2 gene in the urogenital tracts of both sexes, but did not effect expression of the type 1 gene or the cell type-specific expression patterns of the 5 alpha-reductase genes. In the adult prostate, 5 alpha-reductase gene expression is under feedforward control, in which the product of the enzyme, dihydrotestosterone, stimulates the expression of the gene. However, no evidence for feedforward regulation of either 5 alpha-reductase gene was detected in the fetus.

Ischemia and reperfusion reduce the endogenous basic fibroblast growth factor (bF GF) in rat skeletal muscles

Polyclonal antibodies directed against human recombinant basic fibroblast growth factor (bFGF) were used in immunohistochemical studies to localize this growth factor in normal and wounded rat skeletal muscles. bFGF immunoreactivity was found mainly in the extracellular matrix, primarily in the endomysium, including the heparin-containing basal lamina and also in the capillary basal membrane of both normal and wounded muscles, however the signal intensity was much stronger in normal muscles. After 4-hour ischemia, about 40% of skeletal muscle fibers lost their bFGF immunoreactivity. Muscles which experienced 4-hour ischemia and 24 reperfusion had only a weaker bFGF immunoreactivity. The pathological results supported the concept of destroyed cell connection and fiber necrosis in ischemia and reperfused muscles. The mechanisms involved in this reduced concentration of bFGF in wounded muscles included oxygen radical activation, inflammatory response and reduced secretion of endogenous bFGF. These results were only partially compatible with the established mitogenic role of this protein and suggested that a reduction of endogenous FGF may partly contribute to a delay in wound healing.

[Determination of sterigmatocystin in cancerous tissues, blood and urine in patients with liver and stomach cancer]

Sterigmatocystin (ST) was determined with modified Southern-Western blot and indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) for 28 specimens of cancerous tissues, 13 of blood and 20 of urine in 14 patients with liver and stomach cancer. Results showed DNA-ST adduct was detected in 14 specimens of cancerous tissues and/or pericancerous tissues. ST values were higher in four of 13 patients (65-113 micrograms/kg), as compared only in one of 14 healthy persons (68 micrograms/kg). And, ST values all were very low in urine, with a maximum of 13 micrograms/kg.

[Epidemiology of adult diabetes mellitus in a population of Capital Iron and Steel Company in Beijing]

To prevent the development of DM in susceptible individuals, 29859 subjects, aged from 30 to 64 years, from 32 units of the Company were studied by using WHO protocal and diagnostic criteria. The results showed that the average prevalence of DM and IGT was 3.63% and 4.19% respectively, standardized by census 1990 in Beijing, and it was increased with age. No sex difference in the prevalence of DM was found, but the prevalence of IGT was higher in females (5.55%) than in males. The obesity, overweight, positive DM family history and giant baby history, as well as high daily intake of protein were closely related to the prevalence of the disease. Smoking was in effective.

[Changes of fructosamine content and their effects on platelet aggregation of glycosylated modification of low density lipoprotein in vitro]

The changes of fructosamine (FA) in low density lipoprotein (LDL) incubated in different durations and concentrations of glucose, electrophoretic mobility of different degrees of glycosylated modification of LDL, and the effects on platelet aggregation by glycosylated LDL were observed. The results revealed that FA content increased in LDL incubated with glucose and induced glycosylated modification of LDL, and FA content in LDL correlated to the duration of LDL incubated with glucose and also correlated to different concentrations of glucose. There was a positive correlation between electrophoretic mobility and FA content in LDL. The higher of FA content in LDL the higher of platelet aggregation. This study indicated that FA content in LDL reflected the degree of glycosylated modification of LDL, in which the physical, chemical and biological properties were changed.

Acidic fibroblast growth factor reduces rat skeletal muscle damage caused by ischemia and reperfusion

Acute interruption of arterial blood flow to the extremities is often associated with significant morbidity and mortality. Broad-spectrum mitogenic and non-mitogenic activities of FGFs inspired us to study its protecting effects on tissue injuries in ischemia reperfusion condition. We found that systemic administration of aFGF after reperfusion onset prevented severe skeletal muscle injuries. In rats treated with aFGF, the tissue edema was reduced significantly, the tissue viability was increased, and the muscle fibers contained more succinate dehydrogenase (SDH) and adenosine triphosphatase (ATPase). The pathological results supported the concept of improved prevention with aFGF treatment. The possible tissue protection by aFGF may come from its ability to regulate the concentration of extra- and intracellular calcium ion. Besides, it may moderate other Ca2+ dependent enzyme conversion processes. Also, it may take part in the vascular tone regulation under ischemia and reperfusion conditions. These results suggest further study of tissue ischemia prevention with FGF and its possible mechanisms in the future.

Immune dysregulation in TGF-beta 1-deficient mice

Approximately 2 wk after birth, mice having a TGF-beta 1 null mutation (TGF-beta 1(-/-)) exhibit a progressive wasting syndrome and death. Associated with this phenotype is a multifocal infiltration of lymphocytes and macrophages into target organs, especially the heart, lungs, and salivary glands. To explore the consequences of TGF-beta 1 deficiency on the immune system, lymphocyte phenotype and function were analyzed. Initially, lymphoid organ architecture seemed to be normal and, as symptoms developed, the thymus decreased in size, whereas lymph nodes were enlarged. Phenotypically, the TGF-beta 1(-/-) lymphoid cells seemed to be more differentiated in the thymus and activated in the lymph nodes, but remarkably unaffected in the spleen. Moreover, TGF-beta 1(-/-) spleen and lymph nodes displayed enhanced numbers of proliferating cells, as measured by proliferating cell nuclear Ag and/or cyclin-dependent kinase levels. Consistent with this hyperproliferative response, constitutive levels of IL-2 mRNA were elevated in the thymus and both IL-2 and IL-2R mRNA were increased in the lymph nodes. In contrast with the activation profile of TGF-beta 1(-/-) lymphoid cells in vivo, mitogen challenge of these cells in vitro revealed suppressed proliferation that was associated with a defect in inducible IL-2 mRNA expression and IL-2 secretion. Moreover, the addition of rIL-2 restored the deficient mitogen-induced proliferation. The mechanism leading to T cell anergy remains unclear; however, these data confirm the essential role for TGF-beta 1 in maintaining normal immune function.

Immune dysregulation in TGF-beta 1-deficient mice

Approximately 2 wk after birth, mice having a TGF-beta 1 null mutation (TGF-beta 1(-/-)) exhibit a progressive wasting syndrome and death. Associated with this phenotype is a multifocal infiltration of lymphocytes and macrophages into target organs, especially the heart, lungs, and salivary glands. To explore the consequences of TGF-beta 1 deficiency on the immune system, lymphocyte phenotype and function were analyzed. Initially, lymphoid organ architecture seemed to be normal and, as symptoms developed, the thymus decreased in size, whereas lymph nodes were enlarged. Phenotypically, the TGF-beta 1(-/-) lymphoid cells seemed to be more differentiated in the thymus and activated in the lymph nodes, but remarkably unaffected in the spleen. Moreover, TGF-beta 1(-/-) spleen and lymph nodes displayed enhanced numbers of proliferating cells, as measured by proliferating cell nuclear Ag and/or cyclin-dependent kinase levels. Consistent with this hyperproliferative response, constitutive levels of IL-2 mRNA were elevated in the thymus and both IL-2 and IL-2R mRNA were increased in the lymph nodes. In contrast with the activation profile of TGF-beta 1(-/-) lymphoid cells in vivo, mitogen challenge of these cells in vitro revealed suppressed proliferation that was associated with a defect in inducible IL-2 mRNA expression and IL-2 secretion. Moreover, the addition of rIL-2 restored the deficient mitogen-induced proliferation. The mechanism leading to T cell anergy remains unclear; however, these data confirm the essential role for TGF-beta 1 in maintaining normal immune function.

Effect of postexposure vaccination in a chimpanzee model of hepatitis A virus infection

Passive transfer of antibodies to hepatitis A virus (HAV) in immune globulin (IG) effectively prevents hepatitis A when given after exposure, but does not provide lasting protection from infection. Hepatitis A vaccines have been shown to generate quickly levels of antibody equivalent to those found after IG administration. The effect of hepatitis A vaccine in preventing infection following fecal-oral exposure was evaluated in a chimpanzee model of HAV infection. Two animals were vaccinated 1 and 3 days, respectively following inoculation and two inoculated animals served as unprotected controls. Of the two immunized animals, one had no evidence of HAV infection, while the other had an attenuated infection with no evidence of virus shedding. These results suggest that while postexposure hepatitis A vaccination may be infection permissive, it attenuates disease expression and prevents virus shedding.

[The role tumor necrosis factor in multiple organ dysfunction caused by bowel ischemia and reperfusion]

To explore the role of tumor necrosis factor (TNF) in the pathogenesis of multiple organ dysfunction following bowel ischemia and reperfusion, 98 rats were subjected to occlusion of the superior mesenteric artery for 45 minutes. It was found that the plasma TNF level increased rapidly after release of the clamp, peaking to 27.59 +/- 11.13 ng/ml 2 hours after reperfusion. Its changes in quantity was directly related to endotoxin in the portal circulation. Furthermore, the results showed that pretreatment with monoclonal antibody to TNF-alpha could significantly lowered the plasma TNF content and notably improved the functions of various organs. This study demonstrated that release of TNF might result in systemic hypotension and remarkable damage to liver, kidneys and lungs, which contributed to the development of sepsis and multiple system organ failure following severe ischemia-reperfusion injury of the intestine.

Contents of trace elements in the hair of aplastic anemia patients and their treatment based on an overall analysis of symptoms and signs

The content of 12 trace elements in the hair of 20 aplastic anemia patients was determined and compared with that of normal subjects as control. The results showed that patients with deficiency of yin had a significant decrease in lithium, calcium, strontium, and chromium, those with deficiency of yang had a distinct decrease in zinc magnesium barium, strontium, calcium, and lithium, and those with deficiency of both yin and yang had a general decrease in all the 12 trace elements. Changes in trace element content in hair may serve as a guide to opening up new vistas in the treatment of aplastic anemia on the basis of an overall analysis of symptoms and signs.

Synthetic fibronectin peptides interrupt inflammatory cell infiltration in transforming growth factor beta 1 knockout mice

Pronounced mononuclear leukocyte (MNL) infiltration occurs in multiple organs of mice homozygous for a transforming growth factor beta 1 (TGF-beta 1) loss-of-function gene mutation [TGF-beta 1 (-/-)], followed by cachexia and eventually death. Consistent with the increased leukocyte adhesion and tissue infiltration, MNLs isolated from spleen, thymus, and peripheral blood of symptomatic TGF-beta 1 (-/-) mice, as compared to littermate controls, exhibited increased adhesion to extracellular matrix proteins and to endothelial cells in vitro. Incubation of TGF-beta 1 (-/-) MNLs with selected synthetic peptides corresponding to cell- and heparin-binding sequences of fibronectin (FN) significantly attenuated adhesion of these cells not only to FN but also to endothelial cells in vitro. Based on these observations, mice were treated with the FN peptides in an attempt to rescue them from tissue inflammation and cardiopulmonary failure. Daily injections of a combination of four synthetic FN peptides that interact with beta 1-integrins and/or cell surface proteoglycans blocked the massive infiltration of MNLs into the heart and lungs of TGF-beta 1 (-/-) mice. Peptide treatment initiated on day 8, coincident with the first evidence of increased leukocyte-endothelial cell interactions, not only blocked tissue infiltration but also moderated the lethal wasting syndrome.

Normal T cell receptor-mediated signaling in T cell lines stably expressing HIV-1 envelope glycoproteins

A series of T cell lines transfected to stably express HIV-1 envelope (env) glycoproteins were analyzed for viability and for T cell signaling. One transfectant was distinguished by its stable expression of gp120 and gp41, whereas the remainder of the T cell lines were similar to previously reported env-expressing T cells in synthesizing predominantly unprocessed env glycoprotein gp160. All of the transfectants were additionally constructed to express tat and rev proteins. None of these cell lines displayed growth abnormalities or spontaneous cell fusion, although the cell line synthesizing env gp120/gp41 could be induced to fuse and die when cocultured with a second cell expressing surface CD4. A cell line expressing only gp160 and the transfectant expressing gp160, gp120, and gp41 could be triggered normally via CD3-cross-linking as measured by protein tyrosine phosphorylation and by the induction of the CD69 activation marker. At levels of env protein expression sufficient to mediate syncytium formation and to kill cells, these HIV-1 env transfectants displayed no intrinsic T cell signaling abnormalities, suggesting that mechanisms other than a direct intracellular action of the tat or env proteins may be contributing to the deficit in Ag-specific T cell activation described subsequent to HIV infection in vivo and in vitro.

Normal T cell receptor-mediated signaling in T cell lines stably expressing HIV-1 envelope glycoproteins

A series of T cell lines transfected to stably express HIV-1 envelope (env) glycoproteins were analyzed for viability and for T cell signaling. One transfectant was distinguished by its stable expression of gp120 and gp41, whereas the remainder of the T cell lines were similar to previously reported env-expressing T cells in synthesizing predominantly unprocessed env glycoprotein gp160. All of the transfectants were additionally constructed to express tat and rev proteins. None of these cell lines displayed growth abnormalities or spontaneous cell fusion, although the cell line synthesizing env gp120/gp41 could be induced to fuse and die when cocultured with a second cell expressing surface CD4. A cell line expressing only gp160 and the transfectant expressing gp160, gp120, and gp41 could be triggered normally via CD3-cross-linking as measured by protein tyrosine phosphorylation and by the induction of the CD69 activation marker. At levels of env protein expression sufficient to mediate syncytium formation and to kill cells, these HIV-1 env transfectants displayed no intrinsic T cell signaling abnormalities, suggesting that mechanisms other than a direct intracellular action of the tat or env proteins may be contributing to the deficit in Ag-specific T cell activation described subsequent to HIV infection in vivo and in vitro.

Clinical and prognostic investigations on M2/t(8;21) acute nonlymphocytic leukemia

Clinical and prognostic investigations were conducted in 46 cases of M2/t(8;21) leukemia and 29 cases of M2/NN patients. Results showed that most patients with M2/t(8;21) were young males with higher incidence of extramedullary infiltrations. Complete remission rate was higher but with earlier relapse. The prognosis of patients with M2/t(8;21) with loss of one sexual chromosome was poor.

Lipid composition and fluidity of the human immunodeficiency virus envelope and host cell plasma membranes

Previous studies have indicated that human immunodeficiency virus (HIV) is enclosed with a lipid envelope similar in composition to cell plasma membranes and to other viruses. Further, the fluidity, as measured by spin resonance spectroscopy, is low and the viral envelope is among the most highly ordered membranes analyzed. However, the relationship between viral envelope lipids and those of the host cell is not known. Here we demonstrate that the phospholipids within the envelopes of HIV-1RF and HIV-2-L are similar to each other but significantly different from their respective host cell surface membranes. Further, we demonstrate that the cholesterol-to-phospholipid molar ratio of the viral envelope is approximately 2.5 times that of the host cell surface membranes. Consistent with the elevated cholesterol-to-phospholipid molar ratio, the viral envelopes of HIV-1RF and HIV-2-L were shown to be 7.5% and 10.5% more ordered than the plasma membranes of their respective host cells. These data demonstrate that HIV-1 and HIV-2-L select specific lipid domains within the surface membrane of their host cells through which to emerge during viral maturation.

Antibody response to nonstructural proteins of hepatitis A virus following infection

The nonstructural proteins of hepatitis A virus (HAV), produced during active virus replication, are alternative antigens that could be used to differentiate disease from inactivated vaccine-induced antibodies. An assay based on immune precipitation of proteins translated from transcripts of the P2 region of viral cDNA was used to evaluate the development of antibodies after natural infection or vaccination. Antibodies against P2 proteins were found in all sera from clinical cases of hepatitis A following the acute phase. Chimpanzees vaccinated with inactivated or cell-adapted HAV had no detectable antibodies against P2 products, either before or after wild type virus challenge. A serosurvey of sera positive for total anti-HAV (HAVAB, Abbott Laboratories, North Chicago) suggested that some individuals had no detectable antibodies to the P2 antigen by immune precipitation. These results were attributed to the lower sensitivity of the immunoprecipitation assay, since antibodies to capsid proteins, as measured by immunoprecipitation, were also not detected in most of these sera.

The role of endotoxin in the pathogenesis of experimental multiple system organ failure: a preliminary report

In this study, an animal model of multiple system organ failure (MSOF) in rabbits, engendered by feeding E. coli prior to severe hemorrhagic shock, was used for the purpose of investigating 1) the relationship between lipopolysaccharide (LPS) and MSOF, and 2) the effectiveness of Re-LPS antiserum in preventing MSOF. The results showed that endotoxemia occurred very early, and its degree correlated well with that of organ dysfunction. Re-LPS antiserum administration abated the toxic effects and lowered the incidence of MSOF. These results suggest that sequential analysis of circulating LPS levels may be useful for the early diagnosis of MSOF, and that gut-derived endotoxin might play an important role in the pathogenesis of experimental MSOF.

Signals delivered via the Qa-2 molecule can synergize with limiting anti-CD3-induced signals to cause T lymphocyte activation

Qa-2 is a glycolipid anchored, MHC encoded class I molecule expressed at high levels on all murine peripheral T lymphocytes. Anti-Qa-2 antibodies have previously been found to stimulate T cells to proliferate in the presence of crosslinking antibody and PMA. We have examined the effect of anti-Qa-2 antibodies on T cells stimulated with a suboptimal concentration of immobilized anti-CD3. When anti-Qa-2 antibodies were co-immobilized with limiting anti-CD3, in the absence of PMA, a clear augmentation of T cell proliferation was seen. Interestingly, the co-stimulatory anti-Qa-2 antibodies could be directed against epitopes mapped to either the alpha 3 or the alpha 1/alpha 2 Qa-2 domains. As was the case with activation induced by soluble/crosslinked anti-Qa-2 antibodies plus PMA, CD8+ T cells were less able to be costimulated with anti-Qa-2 antibodies than CD4+ cells. Surprisingly, Ca2+ mobilization was only seen when two anti-Qa-2 antibodies reactive to separate structural domains were co-crosslinked on the surface of Indo-1 loaded T cells with a suboptimal concentration of anti-CD3. Collectively these results raise questions regarding the mechanism of Qa-2 mediated signaling and its potential role in T cell activation.

Multiple organ injuries after abdominal high energy wounding in animals and the protective effect of antioxidants

Multiple organ injuries caused by high energy abdominal wounds were studied in 8 pigs and 24 dogs, and at the same time the protective effect of antioxidants in 14 dogs with multiple organ injuries was also studied. The experimental results showed that: 1) more than two organs (six organs at most) were wounded in each of the animals studied; 2) the injuries were characterized by hemorrhaging, tissue rupture and hematoma, and the main pathologic changes were local edema and necrosis; 3) the marked increase of lipid peroxide (LPO) levels in the vital organs indicated that multiple organ injuries could also involve the molecular level; 4) the injuries were due to the direct effect of pressure waves and ischemic reperfusion and not to shock or infection; and 5) antioxidants (vitamin E and Salvia miltiorrhiza Bge.) exhibited significant protective effects against multiple organ injuries through a free radical mechanism.

Participation of tyrosine phosphorylation in the cytopathic effect of human immunodeficiency virus-1

Protein tyrosine phosphorylation is a common mechanism of signaling in pathways that regulate T cell receptor-mediated cell activation, cell proliferation, and the cell cycle. Because human immunodeficiency virus (HIV) is though to affect normal cell signaling, tyrosine phosphorylation may be associated with HIV cytopathicity. In both HIV-infected cells and transfected cells that stably express HIV envelope glycoproteins undergoing HIVgp41-induced cell fusion, a 30-kilodalton protein was phosphorylated on tyrosine with kinetics similar to those of syncytium formation and cell death. When tyrosine phosphorylation was inhibited by the protein tyrosine kinase inhibitor herbimycin A, envelope-mediated syncytium formation was coordinately reduced. These studies show that specific intracellular signals, which apparently participate in cytopathicity, are generated by HIV and suggest strategies by which the fusion process might be interrupted.

[On the relation between substance P and physostigmine on cardiovascular control in rabbit brain]

Using an electromagnetic flowmeter technique, the cardiac output as measured by blood flow in the aortic arch was measured during intracerebroventricular injection (icv.) of Substance P (SP) and physostigmine in 47 anesthetized rabbits. Carotid artery blood pressure and heart rate were recorded. After icv of SP (20 micrograms/20 microliters) or physostigmine (60 micrograms/20 microliters), both cardiac output and mean artery pressure were increased. Pretreatment with icv. of atropine (150 micrograms/20 microliters) did not alter the effect of SP, but the effect of physostigmine was blocked by pretreatment with SP blocker (25 micrograms/20 microliters). These findings suggest that cerebral SP is involved in cholinergic mechanisms on the central control of blood pressure.

[The variations of PRL, LH, FSH and testosterone in renal disease]

Blood PRL was measured with RIA in 22 males and 19 females with various degrees of renal insufficiency. At the same time, blood LH, FSH, testosterone were studied in all the male patients and 20 sex-age matched healthy subjects. The results showed that the levels of PRL and LH were increased, and the level of testosterone was decreased significantly in male uremic patients. There was a significant negative correlation between PRL and testosterone. All the above parameters were measured again 8-25 days after continuous ambulatory peritoneal dialysis (CAPD) therapy in 5 male uremic patients. The BUN and Cr levels decreased and the clinical manifestations of uremia improved, but the levels of PRL, LH, FSH and testosterone showed no significant changes. The mechanisms of these variations were discussed.