[Progress in the effect of human epididymis protein 4 on sperm maturation]

Human epididymis protein 4(HE4) is a secretory glycoprotein found in human distal epididymis epithelial cells. It is often used in the early diagnosis, efficacy evaluation and monitoring of ovarian cancer, and also has been considered as an effective serum marker for many other types of cancer. However, its function in the process of sperm maturation is not fully unknown. The maturation of sperm in epididymis is characterized by the acquisition of motility and fertilization. As a member of the whey acid protein (WAP) family, several studies proposed the importance of HE4 in the maturity of sperm in epididymis. This article reviews the effect of HE4 on spermatozoa maturation in epididymis, which provides basis for the evaluation of male reproductive ability, early detection, early diagnosis and pathogenesis of male infertility.

Compression-induced structural and mechanical changes of fibrin-collagen composites

Fibrin and collagen as well as their combinations play an important biological role in tissue regeneration and are widely employed in surgery as fleeces or sealants and in bioengineering as tissue scaffolds. Earlier studies demonstrated that fibrin-collagen composite networks displayed improved tensile mechanical properties compared to the isolated protein matrices. Unlike previous studies, here unconfined compression was applied to a fibrin-collagen filamentous polymer composite matrix to study its structural and mechanical responses to compressive deformation. Combining collagen with fibrin resulted in formation of a composite hydrogel exhibiting synergistic mechanical properties compared to the isolated fibrin and collagen matrices. Specifically, the composite matrix revealed a one order of magnitude increase in the shear storage modulus at compressive strains>0.8 in response to compression compared to the mechanical features of individual components. These material enhancements were attributed to the observed structural alterations, such as network density changes, an increase in connectivity along with criss-crossing, and bundling of fibers. In addition, the compressed composite collagen/fibrin networks revealed a non-linear transformation of their viscoelastic properties with softening and stiffening regimes. These transitions were shown to depend on protein concentrations. Namely, a decrease in protein content drastically affected the mechanical response of the networks to compression by shifting the onset of stiffening to higher degrees of compression. Since both natural and artificially composed extracellular matrices experience compression in various (patho)physiological conditions, our results provide new insights into the structural biomechanics of the polymeric composite matrix that can help to create fibrin-collagen sealants, sponges, and tissue scaffolds with tunable and predictable mechanical properties.

Synthesis of spiropyrazoline oxindoles by a formal [4 + 1] annulation reaction between 3-bromooxindoles and in situ-derived 1,2-diaza-1,3-dienes

A formal [4 + 1] annulation reaction of 3-bromooxindoles and in situ-derived 1,2-diaza-1,3-dienes has been developed to provide an efficient route to various spiropyrazoline oxindoles with high yields.

SNCR De-NOx within a moderate temperature range using urea-spiked hydrazine hydrate as reductant

In this research, urea-spiked hydrazine hydrate solutions are used as reductants for the Selective Non-Catalytic Reduction (SNCR) De-NOx process below 650 °C. The urea concentration in the urea/hydrazine hydrate solutions is chosen through experimental and theoretical studies. To determine the mechanism of the De-NOx process, thermogravimetric analysis (TGA) of the urea/hydrazine hydrate solutions and their thermal decomposition in air and nitrogen atmospheres were studied to understand their decomposition behaviours and redox characteristics. Then a plug flow reactor (PFR) model was adopted to simulate the De-NOx processes in a pilot scale tubular reactor, and the calculated De-NOx efficiency vs. temperature profiles were compared with experimental results to support the mechanism and choose the proper reductant and its reaction temperature. Both the experimental and calculated results show that when the urea is spiked into hydrazine hydrate solution to make the urea-N content approximately 16.7%-25% of the total N content in the solution, better De-NOx efficiencies can be obtained in the temperature range of 550-650 °C, under which NH3 is inactive in reducing NOx. And it is also proved that for these urea-spiked hydrazine hydrate solutions, the hydrazine decomposition through the pathway N2H4 + M = N2H3 + H + M is enhanced to provide radical H, which is active to reduce NO. Finally, the reaction routes for SNCR De-NOx process based on urea-spiked hydrazine hydrate at the proper temperature are proposed.

Visible-Light-Driven Photocatalytic Activation of Inert Sulfur Ylides for 3-Acyl Oxindole Synthesis

Bicarbonyl-substituted sulfur ylide is a useful, but inert reagent in organic synthesis. Usually, harsh reaction conditions are required for its transformation. For the first time, it was demonstrated that a new, visible-light photoredox catalytic annulation of sulfur ylides under extremely mild conditions, permits the synthesis of oxindole derivatives in high selectivities and efficiencies. The key to its success is the photocatalytic single-electron-transfer (SET) oxidation of the inert amide and acyl-stabilized sulfur ylides to reactive radical cations, which easily proceeds with intramolecular C-H functionalization to give the final products.

Visible-light-induced photocatalytic azotrifluoromethylation of alkenes with aryldiazonium salts and sodium triflinate

Visible light photocatalytic azotrifluoromethylation of alkenes with aryldiazonium salts and sodium triflinate is described, which gave the trifluoromethylated azo compounds in good yields.

Application of biochar from sewage sludge to plant cultivation: Influence of pyrolysis temperature and biochar-to-soil ratio on yield and heavy metal accumulation

Applying biochar products from sewage sludge (SS) pyrolysis as soil amendment for plant cultivation was investigated in this study with special attention paid to heavy metal accumulation in the plants when pyrolysis temperature and biochar-to-soil mass ratio (C:S) were changed. Biochar obtained at four different temperatures were adopted as soil amendment for Allium sativum L. garlic plant cultivation. Experimental results revealed that biochars were rich in nutrient contents and they improved garlic yields. Although contents of heavy metals including As, Zn, Pb, Ni, Cd, Cr and Cu, etc. were elevated in the biochars compared to local soil, they fell within the acceptable limits for land application and SS is a suitable biochar resource, especially biochar produced at 450°C had rich micropores, relatively stable functional groups in structure and rugged surface to contact well with soil, conducive to its usage as a biochar. The garlic grew faster when planted in the biochar-amended soil and had higher final dry matter yields than those planted in the reference soil, especially biochar produced at 450°C corresponding to the highest final yields. The C:S ratio related to the highest garlic yields changed when the pyrolysis temperature was changed and this ratio was 1:4 for the biochar produced at 450°C. General heavy metal accumulation in the garlic occurred only for the most enriched Zn and Cu, and mainly in the roots & bulbs; in addition this bioaccumulation was increasing as leaching from biochar increased but not increasing with C:S ratio. The garlic planted in soil amended with biochar of 450°C contained the lowest level of heavy metals compared to other biochars. Those results indicated that heavy metal accumulation in plants can be inhibited through proper pyrolysis temperature choice and prevention of heavy metal leaching from the SS biochar.

A combined compensation method for the output voltage of an insulated core transformer power supply

An insulated core transformer (ICT) power supply is an ideal high-voltage generator for irradiation accelerators with energy lower than 3 MeV. However, there is a significant problem that the structure of the segmented cores leads to an increase in the leakage flux and voltage differences between rectifier disks. A high level of consistency in the output of the disks helps to achieve a compact structure by improving the utilization of both the rectifier components and the insulation distances, and consequently increase the output voltage of the power supply. The output voltages of the disks which are far away from the primary coils need to be improved to reduce their inhomogeneity. In this study, by investigating and comparing the existing compensation methods, a new combined compensation method is proposed, which increases the turns on the secondary coils and employs parallel capacitors to improve the consistency of the disks, while covering the entire operating range of the power supply. This method turns out to be both feasible and effective during the development of an ICT power supply. The non-uniformity of the output voltages of the disks is less than 3.5% from no-load to full-load, and the power supply reaches an output specification of 350 kV/60 mA.

Nanometallic glasses: size reduction brings ductility, surface state drives its extent

We report tensile experiments on Ni80P20 metallic glass samples fabricated via a templated electroplating process and via focused ion beam milling, which differed only in their surface energy states: Ga-ion-irradiated and as-electroplated. Molecular dynamics simulations on similar Ni80Al20 systems corroborate the experimental results, which suggest that the transition from brittle to ductile behavior is driven by sample size, while the extent of ductility is driven by surface state.

Establishment of an animal model of biliary ischemic stenosis with clamping in mice

OBJECTIVE

The objective of this study was to explore a method to establish biliary ischemic stenosis in mice.

METHODS

After the optimal time of biliary ischemia was determined, 20 Kunming mice were equally divided into 2 groups. In the experimental group a 0.4-cm length of common bile duct was clamped for 90 minutes with 2 micro-vessel clamps (width = 0.1 cm). The common bile duct was not clamped in the control group. Twenty-one days later, biliary tract visualization was performed in all mice. Blood samples were collected from the inferior vena cava to determine the serum levels of total bilirubin (TBIL) and alanine aminotransferase (ALT). Meanwhile, samples of the common bile duct and liver tissue were extracted for microscopic examination to observe morphological changes.

RESULTS

In the experimental group, obvious dilatation of the common bile duct appeared over the clamp site. There was no dilatation of the common bile duct in the control group. Twenty-one days later, serum levels of TBIL and ALT were significantly higher among the experimental compared with the control group. Microscopic examination showed that the part of common bile duct at the clamp site was significantly expanded, with a smaller or occluded bile duct lumen necrotic mucosa with determination, and tubular wall with fibrosis and excrustation. A few dead liver cells and many inflammatory cells were observed in liver tissue samples.

CONCLUSIONS

A biliary ischemic stenosis model was established using a clamping method in mice, which may provide a reliable technique for basic and clinical research into mechanisms of biliary ischemic stenosis after liver transplantation.

Sirolimus-based immunosuppressive therapy in liver transplant recipient with tacrolimus-related chronic renal insufficiency

BACKGROUND

While providing potent immunosuppression for liver transplant recipients, calcineurin inhibitors (CNI) exhibit nephrotoxicity as a major side effect. The purpose of this study was to evaluate the safety and efficacy of conversion from CNI to sirolimus (SRL) among liver transplant recipients with CNI-induced chronic nephrotoxicity.

METHODS

Between January 2004 and June 2005, we performed conversion in 16 recipients after a median period of 8.5 months after liver transplantation. The indication for conversion was CNI-related nephrotoxicity with a serum creatinine (sCr) value >132.6 umol/L. Renal function was measured before and after conversion to SRL. Clinical and laboratory data related to the clinical course of the patients were recorded to investigate the safety and efficacy of conversion.

RESULTS

Sixteen patients were converted to SRL after developing nephrotoxicity. Their renal function improved gradually after conversion. The levels of sCr decreased significantly within the first 30 days (164.1 +/- 12.48 micromol/L to 130.1 +/- 5.573 micromol/L), and over the next 60 days after conversion (97.86 +/- 11.69 micromol/L to 90.7 +/- 8.95 micromol/L) (P < .01). Similarly, the mean glomerular filtration rate (GFR) increased significantly during the same period. Four recipients experienced hypercholesterolemia, 1 with ankle edema, and 1 with acute rejection. The median follow-up was 2.4 years. No patient discontinued SRL due to side effects. No patient needed dialysis or kidney transplantation during the study period.

CONCLUSIONS

SRL is a safe, effective replacement agent as primary immunosuppressive therapy following withdrawal of CNIs in liver transplant recipients with CNI-induced chronic nephrotoxicity.

Volatility of heavy metals during incineration of tannery sludge in the presence of chlorides and phosphoric acid

Knowledge of the behaviour of heavy metals in the combustion process is a most important factor in selecting disposal alternatives for waste materials. Accordingly, in this work, the vaporization behaviour of highly concentrated heavy metals (Pb, Zn, Cu and Cr) in tannery sludge were investigated experimentally. The sludge was spiked with various chlorine compounds (i.e. PVC, FeCl3, CaCl2 and NaCl) and pre-treated with phosphoric acid in order to evaluate the capacity of enhancement and weakening of the volatility of the heavy metals contained in tannery sludge. The experimental results show that the vaporization percentages increased with increasing ratio of Cl/sludge and temperature, and the accelerating and increasing effect of the addition of chlorides on the vaporization percentage of heavy metals was dependent on the release capacity of chlorine radicals. The vaporization percentages of lead and zinc increased by 15-20%, whereas those of copper and chromium increased by only about 3 and 10% at 800 degrees C. However, heavy metals were not expected to be completely released in the combustion process in spite of the high ratio of Cl/sludge. Alternately, heavy metals contained in tannery sludge can be immobilized effectively by pre-treatment with phosphoric acid. When the 85% phosphoric acid accounted for 10% of dry basis of tannery sludge, the phosphate-treated sludge showed the lowest vaporization percentage of about 3-15% with formation of Ca18Cu3(PO4)14, Ca9Cr(PO4)7, Ca19Zn2(PO4)14 and PbMgP2O7 in the bottom ash.

Indole-3-carbinol and diindolylmethane induce apoptosis of human cervical cancer cells and in murine HPV16-transgenic preneoplastic cervical epithelium

Dietary indole-3-carbinol (I3C) has clinical benefits for both cervical cancer and laryngeal papillomatosis, and causes apoptosis of breast cancer cells in vitro. We asked whether I3C and its major acid-catalyzed condensation product diindolylmethane (DIM), which is produced in the stomach after consumption of cruciferous vegetables, could induce apoptosis of cervical cancer cell lines. We also asked whether this effect could be observed in vivo. In vitro, both I3C and DIM caused accumulation of DNA strand breaks in three cervical cancer cell lines. Induction of apoptosis was confirmed by nuclear morphology, nucleosome leakage, altered cytoplasmic membrane permeability and caspase 3 activation. Neither I3C nor DIM caused apoptotic changes in normal human keratinocytes. In C33A cervical cancer cells, DIM was more potent than I3C [dose at which the number of viable cells was 50% of that in untreated cultures (LD(50)) = 50-60 micromol/L for DIM and 200 micromol/L for I3C in a mitochondrial function assay] and faster acting. Furthermore, I3C reduced Bcl-2 protein in a time- and dose-dependent manner. In HPV16-transgenic mice, which develop cervical cancer after chronic estradiol exposure, apoptotic cells were detected in cervical epithelium by TdT-mediated dUTP nick-end labeling staining and by immunohistochemical staining of active caspase 3 only in mice exposed to 17beta-estradiol (E2) and fed I3C. Rare apoptotic cells were also observed by hematoxylin and eosin staining in the spinous layer of the cervical epithelium in both control and transgenic mice. Estradiol reduced the percentage of these late-stage apoptotic cells in the cervical epithelium of transgenic, E2-treated mice, but this reduction was prevented by I3C. These data confirm the proapoptotic action of I3C on transformed cells in vitro, extend the observations to cervical cancer cells and to DIM and show for the first time that dietary I3C results in increased apoptosis in target tissues in vivo.

Prior-knowledge-based feedforward network simulation of true boiling point curve of crude oil

Theoretical results and practical experience indicate that feedforward networks can approximate a wide class of functional relationships very well. This property is exploited in modeling chemical processes. Given finite and noisy training data, it is important to encode the prior knowledge in neural networks to improve the fit precision and the prediction ability of the model. In this paper, as to the three-layer feedforward networks and the monotonic constraint, the unconstrained method, Joerding's penalty function method, the interpolation method, and the constrained optimization method are analyzed first. Then two novel methods, the exponential weight method and the adaptive method, are proposed. These methods are applied in simulating the true boiling point curve of a crude oil with the condition of increasing monotonicity. The simulation experimental results show that the network models trained by the novel methods are good at approximating the actual process. Finally, all these methods are discussed and compared with each other.

Glycerol production by a novel osmotolerant yeast Candida glycerinogenes

Candida glycerinogenes, an osmotolerant yeast isolated from a natural sample in an environment of high osmotic pressure, had a modest sugar-tolerance and an extremely high glycerol productivity. The optimum conditions for glycerol formation by C. glycerinogenes were a temperature of 29-33 degrees C and a pH of 4-6. The optimum medium for glycerol production consisted of 230-250 g glucose/l, 2 g urea/l and 5 ml corn steep liquor/l (55-65 mg phosphates/l); the pH was not adjusted. The highest yield of glycerol was 64.5% (w/w) based on consumed glucose from 240 g glucose/l, and the highest concentration of glycerol was 137 g/l from 260 g glucose/l. These results were obtained by using a 30-l agitated fermentor under optimal fermentation conditions. In ten batch-fermentations carried out in a 50,000-l airlift fermentor, an average yield of glycerol of 50.67% (w/w) and an average glycerol concentration of 121.9 g/l were obtained from an average 240.6 g glucose/l.

Suppression of breast cancer invasion and migration by indole-3-carbinol: associated with up-regulation of BRCA1 and E-cadherin/catenin complexes

Indole-3-carbinol (I3C) is a compound occurring naturally in cruciferous vegetables and has been indicated as a promising agent in preventing breast cancer development and progression. In the present study we have investigated the effect of I3C on the cell migration and invasion behavior in estrogen receptor positive MCF-7 and estrogen receptor negative MDA-MB-468 human breast cancer cell lines. Both MCF-7 and MDA-MB-468 were poorly invasive cell lines and exhibited modest invasion and migration capacity in the presence of fibronectin as the chemoattractant. I3C (50 or 100 microM) elicited a significant inhibition of in vitro cell adhesion, migration, and invasion as well as in vivo lung metastasis formation in both cell lines. I3C also suppressed the 17beta-estradiol stimulated migration and invasion in estrogen-responsive MCF-7 cells. These results indicate that anti-invasion and antimigration activities of I3C occur via estrogen-independent and estrogen-dependent pathways. Moreover, I3C significantly caused a dose-dependent increase in E-cadherin, three major catenins (alpha, beta, and gamma-catenin) and BRCA1 expression. Our current finding is the first demonstration that I3C can activate the function of invasion suppressor molecules associated with the suppression of invasion and migration in breast cancer cells. Thus, clinical application of I3C may contribute to the potential benefit for suppression of breast cancer invasion and metastasis.

[Analysis of multi-wavelength overlapping chromatographic data by orthogonal projection resolution]

Orthogonal projection resolution(OPR) has been proved to be a high performance chromatographic data processing technique. In this paper, it is applied to the resolution of multi-wavelength chromatographic overlapping peaks. When the highest number of degree of overlapping in chromatogram is less than or equal to the number of wavelengths used, a real resolved chromatogram can be completely obtained from multi-wavelength chromatographic overlapping peaks by this method. When based on dual wavelength chromatographic data analysis, a new method, namely dual wavelength characteristic information analysis (DWCI), used for the base line correction, determination of number of components and region of pure components signal. Analysis of overlapping cases of every components in the overlapping chromatogram is also proposed. DWCI has been successfully used for the analysis of overlapping chromatogram with dual peaks of three components and with single peak of two components. But based on single wavelength chromatographic data, the analysis of these overlapping peaks is a very difficult and complicated problem.

Actinonin, a naturally occurring antibacterial agent, is a potent deformylase inhibitor

Peptide deformylase (PDF) is essential in prokaryotes and absent in mammalian cells, thus making it an attractive target for the discovery of novel antibiotics. We have identified actinonin, a naturally occurring antibacterial agent, as a potent PDF inhibitor. The dissociation constant for this compound was 0.3 x 10(-)(9) M against Ni-PDF from Escherichia coli; the PDF from Staphylococcus aureus gave a similar value. Microbiological evaluation revealed that actinonin is a bacteriostatic agent with activity against Gram-positive and fastidious Gram-negative microorganisms. The PDF gene, def, was placed under control of P(BAD) in E. coli tolC, permitting regulation of PDF expression levels in the cell by varying the external arabinose concentration. The susceptibility of this strain to actinonin increases with decreased levels of PDF expression, indicating that actinonin inhibits bacterial growth by targeting this enzyme. Actinonin provides an excellent starting point from which to derive a more potent PDF inhibitor that has a broader spectrum of antibacterial activity.

Indole-3-carbinol prevents cervical cancer in human papilloma virus type 16 (HPV16) transgenic mice

Mice that express transgenes for human papillomavirus type 16 under a keratin 14 promoter (K14-HPV16 mice) develop cervical cancer when they are given 17beta-estradiol chronically. We asked whether the antiestrogenic phytochemical indole-3-carbinol (I3C), found in cruciferous vegetables, administered at physiological doses, would prevent the cervical-vaginal cancer that is promoted in these mice by high doses of estrogen. We compared mice that were fed a control diet with those that were fed a diet supplemented with 2000 ppm I3C. In the group fed the control diet, at a dose of estradiol of 0.125 mg per 60-day release, 19 of 25 transgenic mice developed cervical-vaginal cancer within 6 months, and the remainder had dysplasia. Only 2 mice of 24 in the group fed the I3C supplemented diet developed cancer, and the remainder had dysplasia or hyperplasia. I3C reduced dysplasia in the nontransgenic mice. Similar results were obtained at a higher dose of estradiol (0.250 mg per 60-day release), and I3C helped to prevent morbidity associated with retention of fluid in the bladder that frequently occurred with the higher estradiol dose. Additionally, I3C appeared to reduce skin cancer in transgenic mice. These data indicate that I3C is a useful preventive for cervical-vaginal cancer and, possibly, other cancers with a papillomavirus component.

Anti-estrogenic activities of indole-3-carbinol in cervical cells: implication for prevention of cervical cancer

BACKGROUND

Cervical cancer constitutes the second most common cancer in women. Estrogen promotes development of cervical cancer in cells infected with high risk human papillomaviruses (HPVs). We asked whether the phytochemical indole-3-carbinol (I3C) has anti-estrogenic activities in cervical cells with the goal of preventing cancer in HPV infected cells.

MATERIALS AND METHODS

Using the cervical cancer cell line CaSki, we evaluated expression of HPV and cytochrome p450 (CYP) enzymes by Northern, RNase protection or quantitative RT-PCR. I3C binding to estrogen receptor was measured by competition with estradiol. Estrogen metabolites were measured by gas chromarography-mass spectrometry (GC-MS).

RESULTS

Estradiol increased expression of HPV oncogenes whereas I3C and the estrogen metabolite 2-hydroxyestrone (2-OHE) abrogated the estrogen-increased expression of HPV oncogenes. Both I3C and 2-OHE competed with estradiol for estrogen receptor binding. I3C enhanced gene expression of CYP enzymes responsible for 2-hydroxylation of estrogen, and induced the formation of 2-OHE.

CONCLUSION

I3C has anti-estrogenic activities which should prevent cancer in cervical cells.

[Effect of radix Salviae miltiorrhizae on production of free radical products from lung during cardiopulmonary bypass operation]

Thirty patients of heart valve replacement were randomly divided into two groups, one as Radix Salviae Miltiorrhizae (RSM) treatment group and the other as control group. Blood samples were taken from right atrium (RA) and left atrium (LA) before cardiopulmonary bypass operation (CPB) and 10 min, 45 min, 2 hours, 6 hours after the removal of the aortic cross-clamp to observe the level of peroxidation product and the changes in leucocyte count. The results showed that the number of leucocyte in LA was smaller than that in RA and the amount of peroxidation product in LA was higher than that in RA (P < 0.01-0.05) during the early phase of the lung reperfusion in control group. There was no significant difference (P > 0.05) in the amount of peroxidation product and the number of leucocyte between LA and RA in RSM treatment group. The results demonstrated that RSM could markedly prevent the lung leucocyte aggregation and reduce the production of lung free radical products. It suggested that the effect of RSM of reducing the production of lung free radical products was related to its effect of preventing the lung leucocyte aggregation.

Characteristics of nitric oxide-evoked [3H]taurine release from cerebral cortical neurons

Pharmacological characteristics of [3H]taurine release evoked by nitric oxide (NO) were investigated using mouse cerebral cortical neurons in primary culture. NO generators such as S-nitroso-N-acetylpenicillamine (SNAP) and sodium nitroprusside (SNP) dose-dependently increased [3H]taurine release from neurons. Such stimulatory effects of NO generators were completely abolished by hemoglobin, a NO radical scavenger, indicating that these [3H]taurine releases might be due to NO liberated from SNAP and SNP. Sodium withdrawal from incubation buffer significantly inhibited the SNAP- and SNP-induced [3H]taurine releases, whereas the removal of calcium showed no alterations in the [3H]taurine release evoked by NO generators. Beta-Alanine and guanidinoethane sulfonate, inhibitors of carrier-mediated taurine transport system, inhibited the SNAP- and SNP-evoked releases of [3H]taurine in a dose-dependent manner. These results indicate that the NO-evoked [3H]taurine release from cerebral cortical neurons is mediated by the reverse process of sodium-dependent carrier-mediated taurine transport system.

Nitric oxide-evoked [3H] gamma-aminobutyric acid release is mediated by two distinct release mechanisms

Mechanisms underlying the release of [3H] gamma-aminobutyric acid (GABA) evoked by nitric oxide (NO) were investigated by use of primary cultured neurons prepared from the mouse cerebral cortex. NO generators such as sodium nitroprusside (SNP) and S-nitroso-N-a etylpenicillamine (SNAP) increased both [3H]GABA release from the neurons and [45Ca2+] influx into the neurons in a dose-dependent manner, which was significantly diminished by hemoglobin. The removal of Ca2+ significantly reduced the NO-induced [3H]GABA release by about 50%. Nipecotic acid and 1-(2-(((diphenylmethylene)amino)oxy)ethyl)-1, 2, 5, 6-tetrahydro-3- pyridinecarboxylic acid (NO-711), GABA uptake inhibitors dose-dependently inhibited the NO-evoked [3H]GABA release in either the presence or absence of Ca2+. The concentration of these GABA uptake inhibitors to suppress the NO-induced release of [3H]GABA was sufficiently lower than that to exhibit the inhibition of [3H]GABA transport into the neurons. In addition, the NO-evoked [3H]GABA release was reduced by approximately 50% when total Na+ in incubation buffer was replaced with equimolar choline, and was also completely abolished by the removal of both Ca2+ and Na+. These results indicate that the release of [3H]GABA evoked by NO is mediated by two release mechanisms, a Ca2+ -dependent release system and the reverse process of the Ca2+ -independent and Na+ -dependent carrier-mediated GABA uptake system.

Nitric oxide-evoked [3H]taurine release is mediated by reversal of the Na(+)-dependent carrier-mediated taurine transport system

The pharmacological characteristics of [3H]taurine release evoked by nitric oxide (NO) were investigated using mouse cerebral cortical neurons in primary culture. N-Methyl-D-aspartate (NMDA) and S-nitroso-N-acetylpenicillamine (SNAP) dose-dependently increased [3H]taurine release from neurons. The NMDA-evoked release of [3H]taurine was reduced to the basal level by N omega-nitro-L-arginine, a NO synthase inhibitor, and MK-801, a noncompetitive antagonist for NMDA receptors. The NMDA- and SNAP-evoked releases of [3H]taurine were completely abolished by hemoglobin, indicating that these [3H]taurine releases were evoked by NO produced by NMDA receptor activation and liberated from SNAP. Withdrawal of Na+ from incubation buffer significantly inhibited the NMDA- and SNAP-induced [3H]taurine releases, whereas removal of Ca2+ produced no alteration in the SNAP-evoked [3H]taurine release. In addition, beta-alanine and guanidinoethane sulfonate, antitransporters of the carrier-mediated taurine transport system, reduced the NMDA- and SNAP-evoked releases of [3H]taurine in a dose-dependent manner. These results indicate that the NO-evoked [3H]taurine release from cerebral cortical neurons is mediated by a reversal of the Na(+)-dependent carrier-mediated taurine transport system.

Hydroxyl radical scavengers enhance nitric oxide-evoked acetylcholine release from mouse cerebral cortical neurons

The effect of hydroxyl radical scavengers on acetylcholine (ACh) release evoked by nitric oxide (NO) generators and N-methyl-D-aspartate (NMDA) was investigated. Dimethylthiourea enhanced dose-dependently NO generators-evoked ACh release. Similarly, uric acid and mannitol significantly facilitated ACh release evoked by NO generators. The NMDA-induced ACh release was also significantly facilitated by hydroxyl radical scavengers. These scavengers themselves showed no effects on ACh release. These results suggest that hydroxyl radicals may modify the mechanism for NO-evoked ACh release.

Facilitation of N-methyl-D-aspartate-evoked acetylcholine release by hydroxyl radical scavengers

Effects of hydroxyl radical scavengers such as dimethylthiourea (DMTU), uric acid and mannitol on acetylcholine (ACh) release evoked by N-methyl-D-aspartate (NMDA) were examined in cerebral cortical neurones. NMDA increased dose-dependently ACh release. This increase in the release was significantly suppressed by MK-801, N omega-nitro-L-arginine and haemoglobin, indicating that NMDA evokes ACh release via the formation of NO subsequent to NMDA receptor activation. DMTU dose-dependently enhanced the NMDA-induced ACh release. Uric acid (100 microM) and mannitol (1 mM) facilitated significantly the NMDA-induced ACh release, although these scavengers themselves showed no effects on ACh release in the absence of NMDA. These results indicate that the removal of hydroxyl radical facilitates the NO-induced ACh release.

Removal of hydroxyl radical increases nitric oxide generators-induced [3H]GABA release from mouse cerebral cortical neurons

We investigated the effect of removal of hydroxyl radical on nitric oxide (NO)-induced [3H]GABA release from cerebral cortical neurons. NO generators, S-nitroso-N-acetylpenicillamine and sodium nitroprusside, significantly increased [3H]GABA release, which was completely abolished by hemoglobin. These results indicate that the release of [3H]GABA evoked by these NO generators is mediated by NO formation. N,N'-Dimethylthiourea (DMTU), a hydroxyl radical scavenger, dose-dependently stimulated the increase of NO-induced [3H]GABA release. Similarly, other hydroxyl radical scavengers such as uric acid and mannitol, significantly enhanced the NO-induced [3H]GABA release. On the other hand, each hydroxyl radical scavenger alone showed no effect on [3H]GABA release in the absence of NO generators. These results indicate that the removal of hydroxyl radical enhances NO-evoked [3H]GABA release from cerebral cortical neurons.

GABAA receptor stimulation enhances NMDA-induced Ca2+ influx in mouse cerebral cortical neurons in primary culture

The effect of GABAA receptor stimulation on N-methyl-D-aspartate(NMDA)-induced [45Ca2+]influx has been examined using primary cultured cerebral cortical neurons. NMDA induced a dose-dependent increase in [45Ca2+]influx, which was blocked by MK-801 in a dose-dependent manner. GABAA receptor agonists significantly enhanced the NMDA-induced [45Ca2+]influx, and this enhancement was dose-dependently inhibited by bicuculline, although picrotoxin and tert-butyl-bicyclo[2.2.2]phosphoro-thionate (TBPS) exhibited no alterations in this stimulatory action of GABAA receptor agonists. Blockers of L-type voltage-dependent calcium channels significantly reduced the NMDA-induced [45Ca2+]influx. The increased [45Ca2+]influx by both NMDA and GABAA receptor agonists was also reduced by verapamil and nifedipine. These results suggest that the enhancement of NMDA-induced [45Ca2+]influx by GABAA receptor stimulation in immature cerebral cortical neurons may be due to the increased opening of voltage-dependent calcium channel by synergestic actions between NMDA and GABAA receptors.

Ethanol-induced alteration in activities of cerebral phosphatidylinositol 4,5-biphosphate-specific and cytosolic phospholipase C in the brain: analysis using NG 108-15 cells and brains from ethanol-inhaled mice

Effect of long-term exposure to ethanol (EtOH) on the phosphatidylinositol 4,5-biphosphate (PIP2)-specific and cytosolic phospholipase C (PLC) activities in neuroblastoma x glioma hybrid (NG 108-15) cells and the brains from EtOH-inhaled mice were investigated. Long-term (2 days) exposure of NG 108-15 cells to EtOH induced significant decrease in PIP2-specific PLC activity dependent on concentration and duration of exposure, although the presence of EtOH in the enzyme assay system induced no alteration in PIP2-specific PLC activity. On the other hand, cytosolic PLC activity in NG 108-15 cells significantly increased by both the long-term exposure of the cells to EtOH and the addition of EtOH into the assay system. These changes in activities of both types of PLC in NG 108-15 cells observed after EtOH exposure recovered rapidly by the removal of EtOH. Moreover, the changes in activities of PIP2-specific and cytosolic PLC in the brain of EtOH-inhaled mice were similar to those found in NG 108-15 cells. These results indicate that EtOH inhibits the activity of PIP2-specific PLC and activates cytosolic PLC in the brain. These changes in cerebral PLC activities are suggested to involve in central action of EtOH and establishment of alcohol dependence.

Presence of N-methyl-D-aspartate (NMDA) receptors in neuroblastoma x glioma hybrid NG108-15 cells-analysis using [45Ca2+]influx and [3H]MK-801 binding as functional measures

In the present study, we have attempted to clarify whether neuroblastoma glioma hybrid NG 108-15 cells (NG cells) possess the NMDA receptor complex using [45Ca2+]influx and [3H]MK-801 binding as functional measures. Glutamate and NMDA dose-dependently increased [45Ca2+]influx and these increases were further enhanced by glycine. Scatchard analysis revealed the presence of a high-affinity binding site for [3H]MK-801 with a KD of 18.8 nM and a Bmax of 0.328 pmol/mg protein. This [3H]MK-801 binding was also increased by NMDA in a dose-dependent manner and this increase was further enhanced by glycine. Both ketamine and MK-801 inhibited glutamate- and NMDA-induced [45Ca2+]influx as well as the increase of [3H]MK-801 binding in a dose-dependent manner. Similarly, Mg2+ and Zn2+ dose-dependently reduced both glutamate-induced [45Ca2+]influx and [3H]MK-801 binding. Spermine, one of the polyamines, showed a biphasic stimulatory effects on glutamate-induced [45Ca2+]influx and [3H]MK-801 binding. These results indicate that NG cells possess a pharmacologically distinct NMDA receptor complex and suggest that these cells may be useful for the analyses on pharmacological and biochemical characteristics of the NMDA receptor complex.

Muscimol prevents neuronal injury induced by NMDA

The effect of muscimol on N-methyl-D-aspartate (NMDA)-induced injury of primary cultured cerebral cortical neurons was examined. NMDA induced a dose-dependent leakage of LDH activity, which was significantly inhibited by (+-)-5-methyl-10,11-dihydro-5H-dibenzo-[a,d]cyclopentan-5,10-imine (MK-801). Muscimol significantly reduced the NMDA-induced increase of lactic dehydrogenase (LDH) leakage, and bicuculline abolished this protective effect of muscimol. Similarly, muscimol reduced the NMDA-induced increase in trypan blue staining of the cells, and bicuculline suppressed this inhibitory action of muscimol. These results suggest that GABAA-receptor stimulation exerts a protective action against the neuronal injury induced by NMDA-receptor activation.

Identification of protein phosphatase inhibitors of the microcystin class in the marine environment

Toxins produced by marine phytoplankton represent a severe global health hazard to humans that eat seafood and are also responsible for massive natural fish kills in specialized bloom situations. Tumour-promoting hepatotoxins from the freshwater microcystin/nodularin class were identified in Northeastern Pacific Ocean, Eastern Canadian and European mussels for the first time. These hepatotoxins were detected at biologically active levels up to three-fold higher than accepted quarantine levels for the diarrhetic shellfish toxin okadaic acid (OA), based on their activity (in microcystin-LR equivalent units) in a liquid chromatography (LC)-linked protein phosphatase bioassay. The presence of microcystins/nodularins in oceanic shellfish identifies a potentially novel class of intoxication which is also prevalent in other forms of marine aquatic life, namely sponges and fish. The widespread presence of prokaryotic microcystins and nodularins in the marine environment may be indicative of the importance of signal transduction pathways involving potent inhibition of protein phosphatases in early marine eukaryotes.

A unified bioscreen for the detection of diarrhetic shellfish toxins and microcystins in marine and freshwater environments

Capillary electrophoresis (CE) coupled with liquid chromatography (LC)-linked protein phosphatase (PPase) bioassay was used to detect sensitivity both diarrhetic shellfish toxins and hepatotoxic microcystins in marine and freshwater samples. This procedure provided a quantitative bioscreen for the rapid optical resolution of either of these toxin families in complex mixtures such as cultured marine phytoplankton, contaminated shellfish and cyanobacteria (natural assemblages). Following detection, identified toxins were purified by an enzyme bioassay-guided two-step LC protocol. Using the latter approach, at least four microcystins were rapidly isolated from a cyanobacteria bloom (largely Microcystis aeruginosa) collected from a Canadian drinking-water lake, including a novel microcystin termed microcystin-XR, where X is a previously unidentified hydrophobic amino acid of peptide residue molecular mass 193 Da. The unified CE/LC-linked PPase bioscreen described provides a powerful capability to dissect multiple toxin profiles in marine or freshwater samples contaminated with either okadaic acid or microcystin classes of toxin.

Chemical and biological evidence links microcystins to salmon 'netpen liver disease'

Evidence is presented that links microcystins to a severe liver disease that occurs in Atlantic salmon that are netpen-reared in coastal British Columbia. Liquid chromatography-linked protein phosphatase bioassay analysis of extracts of liver tissue taken from Atlantic salmon afflicted with netpen liver disease showed the presence of an inhibitor of protein phosphatase that was chromatographically indistinguishable from microcystin-LR. Analysis of liver tissue from healthy control fish showed a complete absence of microcystin-LR. Intraperitoneal injection of microcystin-LR into healthy Atlantic salmon re-created the pathologic changes of netpen liver disease, including diffuse necrosis and hepatic megalocytosis.

The significance of venous drainage in free flap transfer

A skin flap in the anterior abdominal wall of the S-D rat was designed so that it was supplied by the superficial epigastric branch of the femoral artery on the right side. Venous drainage was effected through one of five designs: (1) the superficial epigastric vein on the same side, (2) the lateral abdominal vein on the same side, (3) the lateral abdominal vein on the opposite side, (4) the superficial epigastric vein on the opposite side, or (5) a combination of the latter three. Seventy-seven rats were available for final analysis. The surviving percentage area of the flap was found to improve with increased venous drainage and when the arterial blood had to traverse the flap to reach the diagonally situated draining vein. The use of venae commitante as the draining vein is not satisfactory.

Insulin secretory function in relation to transplanted islet mass in STZ-induced diabetic rats

In vivo insulin secretion was quantified as the AIRg or AIRa in islet-transplanted rats. Male Wistar-Furth rats previously made diabetic by STZ administration (55 mg/kg) were transplanted with 500, 1000, 2000, or 3000 islets infused into the portal vein (n = 12-14 per group) and were compared with sham-treated controls (CN, n = 16). At 4-5 wk posttransplantation, no significant differences were noted in the FPG or fasting plasma insulin of the experimental groups (P > 0.05). Body weight, however, was 10% less (P < 0.05) in rats receiving 500 islets than in controls, indicating an effect of beta-cell deficiency on growth rates. To determine the relationship between islet mass and insulin secretion, we measured AIRg after a 0.3 g/kg glucose bolus in fasted conscious animals. A significant correlation was observed between the AIRg and islet number (r = 0.61, P = 0.0001), and both 500- and 1000-islet groups could be differentiated from controls by ANOVA (500: 8%; 1000: 12% of controls; P < 0.05). During a glycemic potentiation protocol, AIRa was measured at basal and elevated blood glucose (approximately 16 mM). At neither basal nor elevated blood glucose was AIRa correlated with islet number (basal r = 0.0622, P = 0.7834; elevated r = 0.3133, P = 0.1667). None of the groups could be differentiated by ANOVA (elevated 500: 37%; 1000, 68% of controls; P > 0.05). Although this study illustrates that AIRa may be better preserved in islet-transplanted rats, AIRg is the better correlate of islet number.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantification of diarrhetic shellfish toxins and identification of novel protein phosphatase inhibitors in marine phytoplankton and mussels

Liquid chromatography (LC)-linked protein phosphatase 1/2A (PP-1/PP2A) bioassay was used to quantitatively identify diarrhetic shellfish toxins in marine phytoplankton (cultured and natural assemblages) and commercially available mussels. Using this approach, multiple protein phosphatase inhibitor profiles of varying composition were found in diarrhetic mussels from Holland and Canada. Based on LC elution positions and relative activity versus PP-1 and PP-2A, at least six inhibitors distinct from known diarrhetic shellfish toxins were identified and termed mussel phosphatase inhibitor (MPI) 19,22,23,25,33 and 42. The levels of these inhibitors, in okadaic acid equivalent units, varied from 100 pg to 3350 ng per g shellfish tissue. The combined levels of PP-1/2A inhibitors in all instances superseded that of okadaic acid/dinophysistoxin-1 and may contribute to the diarrhetic shellfish toxin profile of the contaminated mussels. The efficacy of LC-protein phosphatase bioassay was established for cultured phytoplankton where picogram levels of okadaic acid could be detected from microgram extracts of Prorocentrum lima. Analyses of plankton net tows from estuarine mussel culture sites in Eastern Canada revealed a heterogeneous population of protein phosphatase inhibitors, with dinophysistoxin-1 being most prevalent. This toxin was predominant for at least 2 months in mussel populations in the immediate vicinity of plankton sampling sites. The results are consistent with a hypothetical model in which marine bacteria, cyanobacteria and dinoflagellates combine to produce a variety of protein phosphatase inhibitors effective against signal transduction pathways in higher eukaryotes.

A comparison of arterial and venous flaps

The survival rate and elastic properties of the anterior abdominal skin flap in Sprague-Dawley rats were studied in three groups of animals. In group 1 where the flaps were supplied by a normal artery, arterial flaps (1A) had better survival rate and elastic properties than venous flaps (1B). In group 2, where the flaps were supplied by an artery with diminished perfusion pressure, the arterial flaps (2A) still had slightly better results than venous flaps (2B). However, in group 3 where the flaps were supplied by a vein, venous flaps (3B) had better results than arterial flaps (3A).

[Prognostic factors and treatment of severe acute pancreatitis]

Seventy two cases of severe acute pancreatitis (SAP) all documented by laparotomy. Fifteen were found to be of edematous and 58 of hemorrhagic and necrotic type, 29 cases died (39.7%). The following 6 items are of prognostic importance in both the survival and the dead groups: (1) Shock, (2) Serum albumin less than 30 g/L. (3) BUN greater than 7 mmol/L, (4) Blood glucose greater than 11.1 mmol/L, (5) Abnormal urine analysis, (6) PaO2 less than 8.6 kPa. Thirty two cases showed positivity of 3 or more of the 6 items, among them 21 died (65.6%). Fourty one cases had 2 or less positive items and 8 (19.5%) died. The mortality rate was not significantly different between the group who had either the edematous or the hemorrhagic necrotizing varieties. It was found that 88.2% of the patients in the dead group had hemorrhagic and necrotizing variety in the peripancreatic and similar pathology appeared in the survival group only in 50% (P less than 0.05). The risk was markedly increased in these patients with systemic complication in the lungs, kidney and brain. We found no effect of vasodilatation drugs (salvia miltiorrhiza and anisodamine) in the treatment of SAP.

[Effect of hyperthermal environment on urinary excretion of beta 2-microglobulin and hydrogen ion]

By randomized sampling, 1387 cases working in various circumstances in Chengdu Seamless Steel Tube Plant had their urine net acid clearance (NAC) and osmotic pressure (OSMP) measured, of whom 407 took urine beta 2m examination in addition. Results show that both NAC and OSMP are much higher in the hyperthermal group than in the non-hyperthermal group. There is no significant difference in beta 2m level between the two groups, which demonstrates that the function of proximal renal tubules of the workers in this plant has not been affected, as their working condition conforms to the standards for the prevention of workers made by the government. However, the beta 2m level in the male workers is obviously higher than that in the female. There exists the possibility that the males have contacted the toxic dust at a longer duration, which may be a factor involved in the tubular disorder. The rise of beta 2m together with age is regarded as due to senile decay. This study has provided available data for the set up of worker's prevention system.

[Evaluation of therapeutic effects of acupuncture in treating ischemic cerebrovascular disease]

In this article, the therapeutic effects of acupuncture and routine drugs in treating 20 cases of ischemic cerebrovascular disease, and in comparison with another 20 cases treated with sole routine drugs were studied. Effects of acupuncture were evaluated from the degree of functional nervous damage, EEG-map and somatosensory evoked potential. After treatment the results were as follows: the marks of functional nervous damage in the test group were reduced 13.0 average, but only 3.75 in the control group. There was a very remarkable difference between these two groups (P less than 0.001). Slow wave of the EEG-map in the test group were reduced 1.70 level average, but only 0.05 in the control group (P less than 0.001). theta wave of the EEG-map in the test group were reduced 1.05 level average, but only 0.25 level in the control group (P less than 0.001). The diversity of latent period of P45 peak wave value between left limbs and right limbs were reduced evidently in the test group and showed a very significant statistical difference. (P less than 0.05) as compared with the control group. The above results revealed that therapeutic effects of acupuncture were objective and were based on neurophysiological mechanism.

[Diagnosis of contaminated small bowel syndrome following subtotal gastrectomy: a comparative study of mannitol-BHT and jejunal bacteriology]

Recent reports from abroad showed that lactulose breath hydrogen test (BHT) is a noninvasive and an accurate method for diagnosing contaminated small bowel syndrome (CSBS). In this study, BHT was carried out with mannitol, an inexpensive and rich-in-source sugar, instead of lactulose. In comparison with the "gold standard" of jejunal bacteriology, it was disclosed that a double peak pattern of breath hydrogen response after oral administration of mannitol was characteristic of CSBS with a sensitivity of 71.4% and a specificity of 66.7%, which are about same as those of the lactulose-BHT used abroad.