[Experimental study on effect of altitude xishi capsule in treating oleic acid induced lung injury in acute hypoxia rats]

OBJECTIVE

To explore the effect and pathophysiological mechanism of Altitude Xishi Capsule (XSC) on lung injury during acute hypoxia.

METHODS

A new model of acute lung injury was established by administering oleic acid into superior vena cava in experimental rat during acute hypoxia, which was formed by putting the animal in a hypobaric room, and reduced the pressure gradually in uniform speed till a simulated environment of 6000 m above sea level was formed and lasted for 12 hours. XSC was given orally to the rat before oleic acid administration. The effect of XSC on the model was observed by determination of PaO2, wet/dry ratio of lung and pathologic examination at 1, 2, 3 and 4 hours separately.

RESULTS

The respiratory frequency of model animal increased markedly, with the water content of lung reduced and aggravated as the hypoxia prolonged. XSC could obviously improve the pulmonary edema and inflammatory cell infiltration in lung.

CONCLUSIONS

The aforesaid acute lung injury model with successful rate of 100%, it resembles the clinical acute lung injury and was useful for research on pathophysiology and treatment of ARDS or acute lung injury, XSC could improve the oleic acid induced lung injury in hypoxia rats by reducing the pulmonary edema and inflammatory cell infiltration.

[Myocardial ischemic reperfusion injury affected by the isozymes of nitric oxide synthase and their gene expression: experimental study]

OBJECTIVE

To study nitric oxide (NO), isozymes of NO synthase (NOS) and their gene expression in the isolated working rat heart after ischemia-reperfusion injury.

METHODS

We quantified the gene expression of the isozymes of NOS by reverse transcription-polymerase chain reaction (RT-PCR), analyzed the myocardial NOS, malondialdehyde (MDA) content, NO, creatine phosphokinase (CPK) in effluent samples from coronary sinus, and measured the heart function before and after ischemia reperfusion. We also studied the effects of dexamethasone(Dex) and bradykinin(BK) introduced into cardioplegia on myocardial ischemia reperfusion injury.

RESULTS

Our study demonstrated that the expression of constitutive NOS(cNOS) mRNA was downregulated and of inducible NOS(iNOS) mRNA upregulated with NO, cNOS decrease and iNOS increase during ischemia reperfusion injury. In Dex-treated group, compared with the control group of ischemia reperfusion, the expression of iNOS mRNA was downregulated, NO and iNOS were reduced, the recovery of myocardial dysfunction was ameliorated and MDA, CPK reduced. In BK-treated group, the expression of NOS mRNA showed no significant change, NO and cNOS were increased. The recovery of myocardial dysfunction was ameliorated. MDA, CPK were also reduced.

CONCLUSION

These results indicated that up- and down-regulation of expression of NOS isozymes could be one of the important mechanisms for myocardial ischemic reperfusion injury. Downregulating the expression of iNOS mRNA and activating cNOS could be helpful in myocardial protection.

Association of petrochemical exposure with spontaneous abortion

OBJECTIVES

To assess the association between petrochemical exposure and spontaneous abortion, a retrospective epidemiological study in a large petrochemical complex in Beijing, China was conducted.

METHODS

Plant employment records identified 3105 women who were married, were 20-44 years of age, and had never smoked. Of those, 3070 women (98.8%) reported at least one pregnancy. From this group, 2853 (93%) of the women participated in the study. According to their plant employment record, about 57% of these women workers reported occupational exposure to petrochemicals during the first trimester of their pregnancy. Trained interviewers administered a standardised questionnaire to this group of women and their husbands, collecting information on reproductive history, pregnancy outcomes, employment history, occupational exposure, smoking habits, alcohol consumption, indoor air pollution, and demographic variables. The results from the womens' first pregnancies were analysed.

RESULTS

There was a significantly increased risk of spontaneous abortion for women working in all of the production plants with frequent exposure to petrochemicals (8.8%; range of 5.8%-9.8%) compared with those working in nonchemical plants (2.2%; range of 0.0%-7.1%). Also, when a comparison was made between exposed and non-exposed groups within each plant, exposure to petrochemicals was consistently associated with an increased risk of spontaneous abortion. The overall odds ratio (OR) was 2.7 (95% confidence interval (95% CI) 1.8 to 3.9) after adjusting for potential confounders. When the analysis was performed with the exposure information obtained from the women' interview responses for (self reported) exposures, the estimated OR for spontaneous abortions was 2.9 (95% CI 2.0 to 4.0). The analysis was repeated by excluding those 452 women who provided inconsistent reports between recalled exposure and work history, and a comparable risk of spontaneous abortion (OR 2.9; 95% CI 2.0 to 4.4) was found. In analyses for exposure to specific chemicals, an increased risk of spontaneous abortion was found with exposure to most chemicals, and the results for benzene (OR 2.5; 95% CI 1.7 to 3.7), gasoline (OR 1.8; 95% CI 1.1 to 2.9), and hydrogen sulphide (OR 2.3; 95% CI 1.2 to 4.4) were significant.

CONCLUSION

An increased risk of spontaneous abortion was found associated with the exposure to petrochemicals, including benzene, gasoline, and hydrogen sulphide.

[The effect of cimeiguo on micronuclei in mice induced by cooking lampblack]

The effect of Cimeiguo on micronuclei in mice induced by cooking lampblack is studied. The results show that the number of micronulei induced by cooking lampblack are increased sighificantly (P > 0.01) with dose-response relationship and inhibited by Cimeiguo.

[Observation of relationship between function and structure of experimental pulmonary artery hypertension in rats and inhibitory effect of garlicin and other herbal medicines]

The paper deals with the treatment of the pulmonary artery hypertention in rats caused by monocrotaline with garlicin, liqustrazine and berbamine and studies the relationship between the function and structure of pulmonary artery and pulmonary artery hypertension before and after use of hypotensive agents. The results show that there is a close relationship between the function and structure of pulmonary artery and pulmonary hypertension, and the inhibitory effect of garlicin is the strongest among the three herbal medicines. The pathogenesis is also studied.

Megalin/gp330 mediates uptake of albumin in renal proximal tubule

Serum albumin filtered in renal glomeruli is reabsorbed very efficiently in the proximal tubule by endocytosis. The present study was undertaken to determine whether megalin/gp330 binds and mediates endocytosis of albumin. Rat serum albumin (RSA) labeled with 125I and colloidal gold particles labeled with bovine serum albumin (BSA) were microinfused into rat surface proximal tubules in vivo, and tubular uptake was determined in the presence or absence of different substances known to interfere with ligand binding to megalin. Binding of 125I-BSA and 125I-RSA to purified megalin was also determined directly using Sepharose columns. The results revealed that the tubular uptake of 125I-labeled RSA was significantly inhibited by receptor-associated protein (RAP), which reduced the uptake by > 50% and by cold RSA. The uptake of BSA gold by the proximal tubule was very intensive. BSA gold was found in small and large endocytic vacuoles, dense apical tubules, and in lysosomes. The uptake was reduced by RAP to 17%, by EDTA to 19%, by BSA to 16%, by megalin to 35%, by cytochrome c to 49%, and, together with gentamicin, there was virtually no uptake. Megalin-Sepharose columns bound 125I-labeled BSA as well as 125I-RSA, the binding was inhibited by RAP and EDTA, and analysis of the eluate revealed the bound tracer to be albumin. In conclusion, the present study demonstrates that megalin is a mediator of albumin reabsorption in renal proximal tubules.

Enhanced CD34 expression of sinusoid-like vascular endothelial cells in hepatocellular carcinoma

The immunohistochemical expression of CD34 (human hematopoietic stem cell and endothelial cell marker) and laminin were studied in chronic liver diseases and hepatocellular carcinoma (HCC) to elucidate whether their expression reflected phenotypic differences between non-cancerous sinusoids and sinusoid-like tumor vessels. In normal liver, hepatic sinusoids were always negative for CD34 and laminin. In chronic hepatitis and cirrhosis, the two antigens were sparsely expressed in capillarized sinusoids at periportal and perinodular area. In advanced HCC, CD34 was strongly and diffusely expressed by the endothelial lining of sinusoid-like tumor vessels. However, early-stage HCC showed a wide spectrum of CD34 expression from negative to focal and diffuse, strongly positive staining in sinusoid-like vessels. Laminin was strongly expressed in advanced HCC but not in early-stage HCC. The results indicate that the enhanced expression of CD34 by sinusoidal endothelial cells may reflect the phenotypic change of endothelial cells in chronic liver diseases and HCC, and that the expression may correlate with the processes of angiogenesis induced by hepatocarcinogenesis.

Activation of the insulin-like growth factor-I receptor inhibits tumor necrosis factor-induced cell death

The effect of insulin-like growth factor (IGF) on tumor necrosis factor (TNF)-induced cell killing was determined for mouse BALB/c3T3 fibroblasts in vitro. Cells maintained in 0.5% fetal bovine serum (FBS) were killed by TNF within 6 h in a concentration-dependent manner, an effect that was prevented by IGF-I. TNF-induced cytotoxicity of 3T3 cells that overexpress the human IGF-I receptor (p6 cells) was prevented by IGF-I alone in the absence of serum. TNF-induced cell death was associated with the morphologic features of apoptosis and the release of low-molecular-weight DNA, both of which were prevented by IGF-I. Neither epidermal growth factor (EGF) nor platelet-derived growth factor (PDGF) protected p6 cells from TNF-induced apoptosis. The specific protective action of the IGF-I receptor was demonstrated further by the marked sensitivity to TNF of embryo fibroblasts derived from mice with targeted disruption of the IGF-I receptor (R-cells) but not of fibroblasts derived from wild-type littermates or R-cells transfected with the cDNA for the human IGF-I receptor. Cycloheximide or actinomycin D markedly reduced the protection offered by IGF-I. IGF-I protection of BALB/c3T3 cells persisted for up to 5 days in the presence of PDGF and EGF, whereas IGF-I lost its effectiveness after 2 days in the absence of growth factors. IGF-I did not prevent TNF-induced release of arachidonic acid. The results demonstrate a specific role for the IGF-I receptor in the protection against TNF cytotoxicity. This action of the IGF-I receptor is mediated by protective cytosolic proteins that exhibit a high rate of turnover and whose levels are regulated principally by factors within serum other than IGF-I.

[Comparison of ancient and modern processing methods for fructus Psoraleae]

The contents of 3 active compounds psoralen, isopsoralen and poisonous bakuchiol in 5 differently processed samples of Fructus Psoraleae were analysed by GC. The results indicate that the content of psoralen and isoporalen in the sample processed by the method of "Leigong's theory of processing" are 3-4 times that in the salt-fried sample, while the content of poisonous bakuchiol shows a tendency to decrease.

Effects of hepatocellular mitogens on cytokine-induced nitric oxide synthesis in human hepatocytes

The synthesis of induced nitric oxide (NO) is regulated by several cytokines, including growth factors produced following hepatic injury and inflammation. However, little information is available on the role of growth factors in regulating the inducible NO synthase in human hepatocytes. The capacity of hepatocellular mitogens (HGF, EGF, and TGF-alpha) to regulate the inducible NO synthase (iNOS) was studied in human hepatocytes incubated with inflammatory cytokines and lipopolysaccharide (LPS). Furthermore, the effects of hepatic mitogens on NO-induced changes in DNA and protein synthesis was studied. It was found that NO-mediated decrease of protein and DNA synthesis were partially reversed by the mitogens. This was associated with a down-regulation in cytokine-mediated hepatocyte NO formation, iNOS mRNA expression, and NOS enzyme activity. Cytokine-induced NO formation or SNAP, an NO donor, added with cytokines increased hepatocyte chromatin condensation but no DNA fragmentation was observed. The increase in chromatin condensation was partially reversed by hepatic mitogens and corresponded with the inhibition of NO production. Thus, the hepatic mitogens, HGF, EGF, and TGF-alpha, all suppress iNOS expression and it is the suppression of iNOS that appears to be responsible for the mitogen-reduced preservation of DNA and protein synthesis and prevention of chromatin condensation.

Ethanol-induced inhibition of cell proliferation is modulated by insulin-like growth factor-I receptor levels

Ethanol inhibits the tyrosine autophosphorylation of the insulin-like growth factor (IGF)-I receptor, an action that correlates with the inhibition of IGF-I-stimulated cell proliferation [J. Biol. Chem. 268:21777-21782 (1993)]. In the current study, the IGF-I-dependent proliferation of mouse BALB/c3T3 cells was completely inhibited by ethanol, but the growth of BALB/c3T3 cells that overexpress the IGF-I receptor (p6 cells) was only partially inhibited by ethanol BALB/ c3T3 cells that simultaneously overexpress both the IGF-I receptor and IGF-I were insensitive to growth inhibition by ethanol. In p6 cells, increasing concentrations of IGF-I overcame the inhibition of IGF-I receptor tyrosine autophosphorylation in the presence of ethanol. The importance of the IGF-I receptor as a specific target for ethanol was further investigated in C6 rat giloblastoma cells that respond mitogenically to both epidermal growth factor (EGF) and IGF-I. The mitogenic response of C6 cells to EGF was abrogated in cells expressing antisense mRNA to the IGF-I receptor. Thus, EGF action in these cells is dependent on activation of an IGF-I/IGF-I receptor autocrine pathway. Indeed, EGF stimulated an increase in IGF-I receptor levels by more than 100%. Ethanol completely inhibited the proliferation of C6 cells in response to either EGF or IGF-I. However, ethanol did not directly interfere with EGF receptor function, because EGF-induced cell proliferation was unaffected by ethanol when added exclusively during a 1-hr exposure to EGF. Ethanol did not interfere with the EGF-induced increase in IGF-I receptor expression. The addition of both EGF and IGF-I overcame the inhibitory action of ethanol. In conclusion, the potency of ethanol as an inhibitor of IGF-I-mediated cell proliferation correlates with the level of IGF-I receptors. In contrast to its effect on the IGF-I-receptor, ethanol has no direct effect on EGF receptor activation.

Fourier transform mass spectrometry-advancing years (1992-mid. 1996)

This article is one of a series of Fourier transform mass spectrometry (FTMS) reviews that has appeared in this journal at ca. 3-4 year intervals. A comprehensive review of the recent theoretical developments, instrumental developments, electrospray ionization (ESI), and MALDI is given. Ion dissociation techniques are also discussed because of their contributions to gaining insight into chemical structure. Special sections have been devoted to discussing the emerging fields of surface analysis, polymer analysis, Buckminsterfullerenes (buckyballs), and hydrogen/deuterium exchange studies. This review, although not all-inclusive, is intended to be a starting point for those wishing to learn more about the current status of FTMS, and also as a representative cross-section of the literature for those familiar with the technique. © 1997 John Wiley & Sons, Inc.

Evidence that epithelial glycoprotein 330/megalin mediates uptake of polybasic drugs

Glycoprotein 330 (gp330) is an endocytic receptor expressed in the renal proximal tubules and some other absorptive epithelia, e.g., in the inner ear. The present study shows that the antifibrinolytic polypeptide, aprotinin, and the nephro- and ototoxic antibiotics, aminoglycosides, and polymyxin B compete for binding of 125I-urokinase-plasminogen activator inhibitor type-1 complexes to purified rabbit gp330. Half maximal inhibition was measured at 4 microM for aprotinin, 50 microM for gentamicin, and 0.5 microM for polymyxin B. Drug binding to gp330 was validated by equilibrium dialysis of [3H] gentamicin-gp330 incubations and binding/uptake studies in rat proximal tubules and gp330-expressing L2 carcinoma cells. Analyses of mutant aprotinins expressed in Saccharomyces cerevisiae revealed that basic residues are essential for the binding to gp330 and renal uptake. The polybasic drugs also antagonized ligand binding to the human alpha 2-macroglobulin receptor. However, the rapid glomerular filtration of the drugs suggests kidney gp330 to be the quantitatively most important target. In conclusion, a novel role of gp330 as a drug receptor is demonstrated. The new insight into the mechanism of epithelial uptake of polybasic drugs might provide a basis for future design of drugs with reduced toxicity.

[Distribution of androgen receptor in primary liver cancer and its clinical significance]

A method of receptor binding assay (RBA) was adopted to measure the distribution of androgen receptor (AR) in liver cancer and tissue in its vicinity in 63 patients with primary liver cancer undergone laparotomy and in non-tumor liver tissue in 7 cases with gastric carcinoma. The results showed (1) AR was demonstrated in the liver cancer tissue and surrounding non-tumorous tissue, and the non-tumor liver tissue. The content of AR in the nucleus was significantly higher than that in the cytoplasm. (2) There was no difference in the amount of AR between the tumor tissue and tissue surrounding it. The expression of AR in the liver cancer tissue or the surrounding tissue was more marked than that in the non-tumor tissue. (3) Expression of AR in the tumor tissue seemed to correlate with more frequent tumor recurrence one year after radical resection.

Observation on 108 normal ophthalmic arteries in 80 patients by digital subtraction angiography

By digital subtraction angiography (DSA), the authors made observations on 108 normal ophthalmic arteries in 80 patients with regard to the origins, courses, branching, morphology and anastomoses of the vessels. The merits and demerits of DSA in observing the ophthalmic artery were discussed.

Activated murine macrophages induce apoptosis in tumor cells through nitric oxide-dependent or -independent mechanisms

Work reported here investigated aspects of macrophage-mediated tumor cell death, in particular the role of apoptosis as a mechanism for nitric oxide (NO)-mediated macrophage tumor cytotoxicity. Nitric oxide induced apoptosis in P815 cells in macrophage P815 cocultures where fragmentation of tumor cell [3H]thymidine-labeled DNA preceded cell lysis (as measured by 51Cr release), paralleled nitrite accumulation, and was prevented by a specific inhibitor of NO synthase, N-MMA. DNA from P815 cells separated from macrophages in culture by a cell-impermeable membrane or exposed to authentic NO gas showed the pattern of internucleosomal cleavage that is characteristic of apoptosis. Additionally, culture of P815 cells with the NO donor sodium nitroprusside was followed by DNA fragmentation. Macrophages also induced apoptosis in L929 cells but, in this case, apoptosis was NO independent and partially inhibited in cocultures by an antitumor necrosis factor alpha monoclonal antibody. The anti-tumor necrosis factor alpha monoclonal antibody fully prevented apoptosis when macrophages and L929 were separated by a cell-impermeable membrane. Exposure of L929 cells to NO gas or sodium nitroprusside did not result in their apoptotic death. Like other immune cytotoxic cells, macrophages can determine tumor cell death through the induction of apoptosis and do so through more than one effector mechanism.

Transcellular transport of ferritin in rabbit renal proximal tubules

The purposes of this study were (1) to determine whether or not transcytosis of protein takes place in vivo in rabbit proximal tubules, using ferritin as a marker, (2) to follow the time course of intracellular transport of ferritin, (3) to study the organelles involved in the sequential intracellular transport of the protein, (4) to compare the intracellular transport in vivo and in vitro, and (5) to compare the intracellular transport in rabbit proximal tubules with transport in rat proximal tubules. Female albino rabbits were prepared for micropuncture, and individual proximal tubules were microinfused with a bolus of cationic ferritin for 2-3 min. The tubules were fixed by perfusion with glutaraldehyde at different time intervals after exposure to ferritin. Ferritin was located in the endocytic vesicles, vacuoles, dense apical tubules and lysosomes including multivesicular bodies, initially in the apical part of the cells, then progressively with time transported to the basal part of the cells. An organelle not previously described represented by small tubulovesicular structures (< 0.05 microns in diameter) also contained ferritin. This organelle was observed either close to large ferritin-loaded vacuoles and sometimes connected to the latter, or scattered throughout the cytoplasm, initially in the apical part of the cell but later found increasingly in the basal part. Small clusters of ferritin particles were found in the basolateral intercellular spaces. After 15 min, only small amounts were observed but the number of clusters increased with time after ferritin infusion. No ferritin particles were observed in the Golgi region.(ABSTRACT TRUNCATED AT 250 WORDS)

Nitric oxide-mediated apoptosis in murine peritoneal macrophages

Nitric oxide (NO) synthase, the enzyme responsible for the generation of the cytotoxic compound NO from L-arginine, is induced in macrophages during activation. Previous work demonstrated that the cytotoxicity of NO extends to the macrophages that produce it, because the activity of NO synthase in these cells correlates inversely with their life span in culture. Data presented here demonstrate that the NO-dependent death of murine peritoneal macrophages activated in vitro with IFN-gamma and LPS is mediated through apoptosis. Evidence in this direction was provided by microscopic examination of the cells, which revealed the presence of nuclear and cytoplasmic alterations characteristic of apoptosis, and by the specific pattern of internucleosomal DNA fragmentation detected by electrophoresis. That these alterations resulted from the production of NO was confirmed by the preventive effects of cell activation in L-arginine-restricted medium or in medium containing an inhibitor of NO synthase, NG-monomethy L-arginine, and more directly by the induction of apoptosis by exposure of the cells to authentic NO gas. Additional results demonstrated that glucose starvation, the inhibition of the tricarboxylic acid cycle with fluorocitrate or of glycolysis with iodoacetate, but not the suppression of the electron transport chain with potassium cyanide, also induced macrophage apoptosis. The potential role of metabolic inhibition as a mechanism for NO-mediated apoptosis, as well as the relationship of these findings with events occurring in wounds and other sites of macrophage infiltration are discussed.

Nitric oxide-mediated apoptosis in murine peritoneal macrophages

Nitric oxide (NO) synthase, the enzyme responsible for the generation of the cytotoxic compound NO from L-arginine, is induced in macrophages during activation. Previous work demonstrated that the cytotoxicity of NO extends to the macrophages that produce it, because the activity of NO synthase in these cells correlates inversely with their life span in culture. Data presented here demonstrate that the NO-dependent death of murine peritoneal macrophages activated in vitro with IFN-gamma and LPS is mediated through apoptosis. Evidence in this direction was provided by microscopic examination of the cells, which revealed the presence of nuclear and cytoplasmic alterations characteristic of apoptosis, and by the specific pattern of internucleosomal DNA fragmentation detected by electrophoresis. That these alterations resulted from the production of NO was confirmed by the preventive effects of cell activation in L-arginine-restricted medium or in medium containing an inhibitor of NO synthase, NG-monomethy L-arginine, and more directly by the induction of apoptosis by exposure of the cells to authentic NO gas. Additional results demonstrated that glucose starvation, the inhibition of the tricarboxylic acid cycle with fluorocitrate or of glycolysis with iodoacetate, but not the suppression of the electron transport chain with potassium cyanide, also induced macrophage apoptosis. The potential role of metabolic inhibition as a mechanism for NO-mediated apoptosis, as well as the relationship of these findings with events occurring in wounds and other sites of macrophage infiltration are discussed.

Three-dimensional organization of the vacuolar apparatus involved in endocytosis and membrane recycling of rat kidney proximal tubule cells. An electron-microscopic study of serial sections

The present study was performed to examine the three-dimensional structure of the vacuolar apparatus involved in endocytosis and especially the membrane recycling pathway of rat renal proximal tubule cells by electron microscopy of serial sections. In five series of consecutive ultrathin sections, endocytic invaginations (INV), small endocytic vacuoles (SEV; < 0.5 micron in diameter), large endocytic vacuoles (LEV; > 0.5 micron in diameter) and dense apical tubules (DAT) were followed. LEV connected to SEV and dense apical tubules were reconstructed from these sections, and the distribution, size, shape and spatial relationships were examined. The analysis of small coated profiles (< 0.5 micron in diameter) in the apical cytoplasm showed that the INV account for 21.3%, SEV connected to DAT account for 36.4% while SEV free in the cytoplasm account for 42.3%. The free SEV generally have a larger diameter than those connected to DAT. Of the DAT, 56.5% are free in the cytoplasm, 36.9% are seen connected to SEV and 6.5% are in continuity with LEV. The reconstructed images showed that LEV are spherical structures connected to DAT and SEV. A quantitative analysis showed that the smaller the surface area of LEV, the higher the relative number of DAT connected, and also shown was that the number of DAT attached to SEV is 2.03 times more than that of DAT connected to LEV. These results demonstrating a three-dimensional model for the vacuolar apparatus involved in the endocytosis and membrane recycling pathway of the proximal tubule cells suggest that DAT originate mainly from SEV but also from LEV, illustrating that membrane recycling occurs at any stage of the initial endocytic process, and implies that most membrane material return to the cell surface via a short, fast recycling route.