Blood flow-dependent prostaglandin f(2alpha) regulates intestinal glucose uptake from the blood

Intestinal glucose uptake (GUi) from blood increased when blood flow (BF) was increased. The increase in BF could elevate shear stress. Therefore, we hypothesize that shear stress-induced release of autacoids mediates the increase in GU(i). A surgically separated segment of small intestine was perfused in situ with the use of an arterial circuit in anesthetized cats. Arterial and portal blood samples were taken simultaneously for assessment of GU(i). Adenosine was used to elevate intestinal BF. The GU(i) increased by 45.0 +/- 18.3 from 25.3 +/- 3.8 micromol. min(-1). 100 g tissue(-1) when the BF increased about four times. It was not a direct effect of adenosine because GU(i) was not altered if the flow was held constant. This increase was blocked by a cyclooxygenase inhibitor, indomethacin, but not by nitric oxide synthase blocker N(G)-nitro-L-arginine methyl ester. Furthermore, prostaglandin F(2alpha) (PGF(2alpha)) but not PGE(2) or PGI(2) reversed the blockade of the increase in GU(i) after indomethacin during elevated blood flow, whereas they had no influence on basal uptake. The results suggest that shear stress-induced release of PGF(2alpha) mediated the increase in GU(i) when blood flow was elevated.

Lifetime tobacco, alcohol and other substance use in adolescent Minnesota twins: univariate and multivariate behavioral genetic analyses

AIMS

We sought to estimate the contribution of genetic and environmental factors to adolescent tobacco, alcohol and other substance use.

DESIGN, SETTING AND PARTICIPANTS

The sample consisted of 327 monozygotic and 174 like-sex dizygotic twin pairs born in Minnesota and aged 17-18 years at time of assessment. Biometrical methods were used to estimate the contribution of additive genetic, shared and non-shared environmental factors to adolescent substance use.

MEASUREMENTS

As part of a day-long psychological assessment, adolescent twins completed a computerized substance use interview to determine whether they had ever used tobacco, alcohol or other illicit drugs.

FINDINGS

The heritability for the liabilities to tobacco, alcohol and other drug use was estimated to be 59%, 60% and 33% among males, and 11%, 10% and 11% among females. However, the gender difference was not statistically significant. Estimates of shared environmental effect were substantial and insignificantly higher among females (71%, 68% and 36%, respectively) than among males (18%, 23% and 23%, respectively). The covariation among the three substance use phenotypes could be accounted for by a common underlying substance use factor. Estimates of the contributions of genetic, shared environmental and non-shared environmental factors to variance in this factor were 23% 63% and 14%, respectively.

CONCLUSIONS

These findings add to the growing behavioral genetic literature indicating that adolescent initiation of substance use, a powerful predictor of adult substance use diagnosis, is influenced primarily by environmental rather than genetic factors.

Blockade of nitric oxide synthase potentiates the suppression of vasodilators by norepinephrine in the hepatic artery

We have previously shown that nitric oxide (NO) and adenosine suppress vasoconstriction induced by norepinephrine infusion and sympathetic nerve stimulation in the hepatic artery and superior mesenteric artery. NO is involved in the control of basal vascular tone in the superior mesenteric artery but not the hepatic artery. The vasodilation induced by adenosine is inhibited by NO in the superior mesenteric artery but not in the hepatic artery. Based on these known interactions of catecholamines, adenosine, and NO, the objective of this study was to test the hypothesis that NO modulates the interaction between vasoconstrictors and vasodilators in the hepatic artery. We examined the ability of norepinephrine to suppress adenosine-mediated vasodilation and the role of NO in this interaction. Hepatic arterial blood flow and pressure were monitored in pentobarbital-anesthetized cats. The maximum hepatic arterial vasoconstrictor response to norepinephrine infusion was potentiated by blockade of NO production using Nomega-nitro-L-arginine methyl ester (L-NAME), and the potentiation was reversed by L-arginine. The maximum dilator response to adenosine was only slightly suppressed (14.0+/-5.8%, P < 0.05) by norepinephrine infusion; however, after the NO blockade, the suppression by norepinephrine of the vasodilation induced by adenosine was substantially potentiated (45.2+/-9.1%, P < 0.05). Similar results were obtained for isoproterenol-induced vasodilation. We conclude that the interaction between these vasodilators and norepinephrine was modulated by NO which inhibited the vasoconstriction and the suppression of vasodilators caused by norepinephrine and that in the absence of NO production, norepinephrine-induced constriction and the ability to antagonize dilation is substantially potentiated.

[Molecular cloning of rat OB gene and its expression in Escherichia coli]

In order to provide rat OB gene product for studying the relationship between obesity and noninfectious diseases, rat OB cDNA was amplified by RT-PCR technique. 460 bp fragment of OB cDNA was subcloned into EcoRI/BamHI site of plasmid pUC 19. Sequence analysis of OB cDNA revealed that the translation reading frame was identical with that reported in the literature. Thereby plasmid pBV220-rOB was constructed and the specific expression of OB gene in E. coli identified by SDS-PAGE electrophoresis was obtained.

Shear stress-induced nitric oxide antagonizes adenosine effects on intestinal metabolism

The influence of nitric oxide (NO) on adenosine-induced metabolic effects was studied in the intestine. Blood flow supplied an in situ- isolated segment of small intestine in anesthetized cats via the superior mesenteric artery (SMA) and was controlled by a vascular circuit. The SMA and portal samples were taken for analysis of oxygen and lactate. Adenosine (0.4 mg. kg-1. min-1, intra-SMA) reduced oxygen consumption by 25.1 +/- 2.9 from 73.1 +/- 10.8 micromol. min-1. 100 g-1 and increased lactate production by 13.3 +/- 3.0 from 12.8 +/- 4.6 micromol. min-1. 100 g tissue-1 during constant-flow (CF, decreased shear stress) but not during constant-pressure (CP, increased shear stress) perfusion. Blockade of NO synthase using Nomega-nitro-L-arginine methyl ester did not affect the metabolic effects of adenosine during CF but eliminated the differences seen between CP and CF perfusion. A NO donor, 3-morpholinosydnonimine, attenuated the metabolic effects of adenosine during CF perfusion. The results suggested that shear-induced NO antagonized metabolic effects of adenosine but that the inhibition of vascular effects by NO was not shear dependent since it occurred in both CP and CF perfusion.

The effect of tea consumption on oxidative stress in smokers and nonsmokers

While the anticarcinogenic effects of tea in animal models have been reported by several groups, human epidemiological studies examining tea consumption and cancer prevention have produced equivocal results. The beneficial properties of tea to human health may be related to the antioxidant properties of tea components. However, little evidence has been provided that tea consumption can either increase the antioxidant capacity or decrease oxidative stress in humans. In the present study, the effects of tea treatment (green tea) on biomarkers of oxidative stress were investigated in smokers and nonsmokers in two volunteer study groups (one in China and the other in United States). Green tea consumption in both study groups decreased oxidative DNA damage (8-OHdG in white blood cells and urine), lipid peroxidation (MDA in urine), and free radical generation (2, 3-DHBA in urine) in smokers. Nonsmokers (US study group) also exhibited a decrease in overall oxidative stress.

The chemopreventive effects of tea on human oral precancerous mucosa lesions

A double-blind intervention trial was conducted in patients with oral mucosa leukoplakia using a mixed tea product developed by the authors. Fifty-nine oral mucosa leukoplakia patients, diagnosed by established clinical and pathological criteria, were randomly divided into a treated group (3 g mixed tea oral administration and topical treatment) and a control group (placebo and glycerin treatment). After the 6-month trial, the size of oral lesion was decreased in 37.9% of the 29 treated patients and increased in 3.4%; whereas the oral lesion was decreased in 10.0% of the 30 control patients and increased in 6.7%. At the same time, the incidence of micronucleated exfoliated oral mucosa cells in the treated group (5. 4 per 1000 cells) was lower than that in the control group (11.3 per 1000 cells)(P < 0.01); whereas it was 1.4 per 1000 cells in 20 healthy subjects. The micronuclei and chromosome aberration rate in the peripheral blood lymphocytes showed the same results. In pathological examination, there were significant differences (P < 0. 05) in the number and total volume of the silver-stained Nucleolar Organizer Regions (AgNOR) and the proliferating index of Proliferation Cell Nuclear Antigen (PCNA) in oral mucosa cell nuclei between the treated group and the control group which indicates that cell proliferation was decreased in the treated patients. The overall results provide some direct evidence on the protective effects of tea on oral cancer.

[Experimental study on anti-oxygen and promoting intelligence development of Codonopsis lanceolata in old mice]

The water labyrinth test and determining lipid peroxide (LPO) contents were used to assay the effects of Codonopsis lanceolata on promoting intelligence development and lipid peroxide. The results showed that latent period of old mice in water labyrinth was statistically shorten and the number of mistake of old mice was visibly reduced by drinking extraction of Codonopsis lanceolate 4 g/kg and 8 g/kg. These indicated that mice drinking extraction of Codonopsis lanceloata learned faster that those of drinking water. The contents of LPO in red blood cell and brain of mice and rate drinking extraction of Codonopsis lanceolata were significantly reduced, the activities of superoxide dismutase (SOD) in serum of rat drinking extraction of Codonopsis lanceolata were visibly increased. These presents that the extraction of Codonopsis lanceolata has the role of promoting learning and memory of old animal, its mechanism might be increasing SOD activity and decreasing LPO level.

Role of nitric oxide and prostaglandins in the potentiating effects of calcitonin gene-related peptide on lipopolysaccharide-induced interleukin-6 release from mouse peritoneal macrophages

Previous data from our laboratory have shown that calcitonin gene-related peptide (CGRP) has a potentiating effect on lipopolysaccharide-(LPS) induced interleukin-6 (IL-6) release from mouse macrophages. However, the mechanism of this effect was not clear. Since the nitric oxide (NO) and prostaglandins (PGs) induced by LPS might modulate IL-6 release, we examined whether NO and PGs were also involved in the potentiating effect of rat CGRP (rCGRP) on LPS-induced IL-6 release from mouse macrophages. The IL-6 level in the medium was measured by enzyme-linked immunosorbent assay. Accumulation of NO was assessed by measuring the presence of nitrite by the Greiss reaction. PGI2 was assessed by measuring the formation of 6-keto-prostaglandin F1alpha (6-keto-PGF1alpha) by radioimmunoassay. The results showed that the potentiating effect of rCGRP (0.1 nm) on LPS-induced IL-6 release was significantly inhibited by either 100 micrometers NG-monomethyl-L-arginine acetate (L-NMMA; an inhibitor of NO synthase) or 10 micrometers indomethacin (an inhibitor of cyclo-oxygenase). The LPS-induced NO and PGI2 production from these cells was increased significantly by rCGRP at 0.01-10 nm in a concentration-dependent manner, which was blocked by L-NMMA and indomethacin. These results suggest that rCGRP enhances the NO production elicited by LPS and subsequently increases the PGs production which is involved in the potentiating effect of rCGRP on LPS-induced IL-6 release from the peritoneal macrophages in the mouse.

Identification and characterization of immunoreactive calcitonin gene-related peptide from lymphocytes of the rat

There is accumulating evidence that the immune system can produce neuropeptides. In the light of these facts, we obtained direct evidences to prove that T lymphocytes also synthesize and secrete calcitonin gene-related peptide (CGRP), a neuropeptide localized within primary sensory nerves. By using CGRP specific RIA, CGRP-like immunoreactivity (LI) was found in the extracts of rat lymphocytes from thymus and mesenteric lymph node. The intracellular concentration of lymphocyte-derived CGRP-LI of rat thymus and mesenteric lymph node was 745+/-39 and 447+/-33 fg/10(6) cells, respectively. CGRP-LI in lymphocytes was shown to co-elute with synthetic rat CGRP and sensory neuron-derived CGRP by reverse-phase HPLC. In addition, the CGRP-LI located in the T lymphocytes was also shown by immunocytochemical method examined by electron microscopy. The CGRP mRNA detected by RT-PCR was also present in these lymphocytes and was also identified to be the same one in sensory neurons. These data suggest that CGRP is synthesized and secreted in T lymphocytes of both thymus and lymph node in the rat, and this is identified to be the same one in neuronal tissue. Lymphocyte-derived CGRP may act in an autocrine/paracrine mode and play an important role in certain physiological and pathophysiological conditions.

[Protection of dl-(15R)-15 methyl-PGE2 methyl ester (PG6E) on experimental ulcers in rats]

The effects of dl-(15R)-15 methyl-PGE2 methyl ester (PG6E), in experimental ulcers induced by absolute alcohol, HCl, indomethacin, pyloric ligation and chronic acetic acid in rats were studied. PG6E at doses 10-80 micrograms.kg-1 was shown to have significant protective effect. PG6E (30-60 micrograms.kg-1) was also found to reduce markedly the acid secretion, pepsin activity, DNA content of the juice collected from pylorus ligated stomach of rats and increase markedly the content of gastric mucosa hexosamine in mice given PG6E (30-60 micrograms.kg-1 po for 3 d). At doses of 40-80 micrograms.kg-1, PG6E was able to have no significant effect on gastric emptying time in rats and gastrointestinal tract movement in mice. It appears that PG6E was shown to inhibit the aggressive factors and increase the protective factors of gastric mucosa. This may hopefully become a new antiulcer agent.

Mechanisms of stretch-induced changes in [Ca2+]i in rat atrial myocytes: role of increased troponin C affinity and stretch-activated ion channels

To study the effects of stretch on the function of rat left atrium, we recorded contraction force, calcium transients, and intracellular action potentials (APs) during stretch manipulations. The stretch of the atrium was controlled by intra-atrial pressure. The Frank-Starling behavior of the atrium was manifested as a biphasic increase of the contraction force after increasing the stretch level. The development of the contraction force after step increase of the stretch (intra-atrial pressure from 1 to 3 mm Hg) was accompanied by the increase in the amplitude of the calcium transients (P<0.05, n=4) and decrease in the time constant of the Ca2+ transient decay. The APs of the individual myocytes were also affected by stretch; the duration of the AP was decreased at positive voltages (AP duration at 15% repolarization level, P<0.001; n=13) and increased at negative voltages (AP duration at 90% repolarization level, P<0. 01; n=13). To study the mechanisms causing these changes we developed a mathematical model describing [Ca2+]i and electrical behavior of single rat atrial myocytes. Stretch was simulated in the model by increasing the troponin (TnC) sensitivity and/or applying a stretch-activated (SA) calcium influx. We mimicked the Ca2+ influx by introducing a nonselective cationic conductance, the SA channels, into the membrane. Neither of the 2 plausible mechanosensors (TnC or SA channels) alone could produce similar changes in the Ca2+ transients or APs as seen in the experiments. The model simulated the effects of stretch seen in experiments best when both the TnC affinity and the SA conductance activation were applied simultaneously. The SA channel activation led to gradual augmentation of Ca2+ transients, which modulated the APs through increased Na+/Ca2+-exchanger inward current. The role of TnC affinity change was to modulate the Ca2+ transients, stabilize the diastolic [Ca2+]i, and presumably to produce the immediate increase of the contraction force after stretch seen in experiments. Furthermore, we found that the same mechanism that caused the normal physiological responses to stretch could also generate arrhythmogenic afterpotentials at high stretch levels in the model.

[Relationship of serum trace elements to lung cancer and its clinical application]

The levels of serum trace elements Cu, Zn, Fe, Mn and Ca were measured by PE3030 atomic absorption spectrophotometer in 300 patients with lung cancer, 50 with nonmalignant pulmonary diseases and 100 healthy subjects. In addition, these trace elements were also measured in 60 cases with lung cancer (40 remitted, 20 non-remitted) before and after treatment. Results showed that the concentrations of serum Cu, Mn and Cu/Zn ratio were significantly higher (P < 0.01) but Zn, Ca were significantly lower (P < 0.05-0.01) in lung cancer and nonmalignant pulmonary diseases than in healthy controls. Within the three groups there has no difference among profession, area and age discovered. In the remitted patients with lung cancer, the levels of serum Cu and Cu/Zn ratio were significantly lower (P < 0.01) but Zn, Ca were significantly higher (P < 0.01) after treatment. In the non-remitted group, only Cu/Zn ratio was significantly higher (P < 0.01) after treatment. Multivariable logistic regression analysis showed that the Odds Ratio (OR) of serum Ca was 0.9950 with 95% Confidence interval (CI) 0.9910-0.9990, and the OR of Cu/Zn was 7.9914 with 95% CI 3.4310-18.6134. It was suggested that Ca might play a protective vole while Cu/Zn ratio a risk factor for lung cancer. Results also showed that if the threshold of Cu/Zn ratio set at 1.10 in the healthy control group, the positive rate of Cu/Zn ratio was 68% which might be important in diagnosis and to assessing the prognosis of lung cancer.

[Effects of Curcuma phaeocaulis on learning and memory and lipid peroxide in mice]

Nine months mice were inoculated and the method of water maze test and lipid peroxide determination to study the effects of extract of Curcuma phaeocaulis Valeton on learning and memory ability and retarding of senescence. Results showed that in water maze test the time for the group with Curcuma phaeocaulis Valeton needed from initial position to the end was significantly shortened compared with old control. The error numbers for the group of Curcuma phaeocaulis Valeton were significantly decreased compared with old control after starting experiment for 18 days and 24 days and for 35 days no significance difference was showed between groups. The levels of brain, liver and red blood cells lipid peroxide in the group with Curcuma phaeocaulis Valeton were considerably lower than old control, hemoglobin content was considerably increased than old control.

[Induction of NAD(P)H: quinone reductase by anticarcinogenic ingredients of tea]

By assaying the activity of NAD(P)H: quinone reductase (QR) in Hep G2 cells exposed to inducing agents, a variety of ingredients in tea, we compared their abilities on inducing QR and preventing cancer. The results showed that tea polyphenols, tea pigments and mixed tea were all able to induce the activity of QR significantly. The single-component ingredients of tea polyphenols and tea pigments, including thearubigens, EGCG and ECG, also enhanced the activity of QR. But EGC, EC, theaflavins, tea polysaccharide and tea caffeine, showed no apparent induction of QR. We found that among those tea ingredients studied, the multi-component ingredients were more effective than the single-component ones. So we thought that the abilities of antioxidation and cancer prevention of tea depended on the combined effects of several kinds of active ingredients, which mainly include tea polyphenols and tea pigments.

Functional assessment of alpha 1-adrenoceptor subtypes in porcine coronary artery

1. alpha 1-Adrenoceptors are known to play an important role in vasoconstriction in response to adrenergic stimulation. However, the functional importance of alpha 1-adrenoceptor subtypes at the epicardial coronary artery remains unclear. We examined alpha 1-adrenoceptor subtypes by comparing functional affinities for alpha-adrenoceptor antagonists on noradrenaline (NA)-induced vasoconstriction in porcine denuded right coronary arteries. 2. Noradrenaline induced a dose-dependent vasoconstriction in incubated vessel rings. Prazosin and phentolamine were potent and competitive antagonists for NA-induced contraction (pA2 10.27 and 9.03, respectively). In contrast, the selective alpha 2-adrenoceptor antagonist yohimbine had a low affinity (pA2 6.13). Two selective alpha 1A-adrenoceptor antagonists, WB 4101 and 5-methyl urapidil, were potent and competitive antagonists of alpha 1-adrenoceptor-induced contraction (pA2 10.67 and 8.90, respectively) and the selective alpha 1D-adrenoceptor antagonist BMY 7378 had a low affinity (pA2 6.06). Noradrenaline-induced contraction was insensitive to the alkylating effects of chlorethylclonidine. These observations indicate that the vasoconstriction is predominantly mediated by the alpha 1A-adrenoceptor subtype. This was also supported by a good correlation between pA2 values from the present study and reported binding affinities (pKi) of various alpha-adrenoceptor antagonists with cloned human alpha 1A-adrenoceptors (r = 0.98), but not for alpha 1B- or alpha 1D-adrenoceptor subtypes (r = 0.77 and 0.41, respectively). 3. Our results indicate that the alpha 1A-adrenoceptor is the main functional receptor subtype in porcine denuded coronary arteries.

Ca2+-dependence of vasoconstriction mediated by alpha1A-adrenoceptors in perfused rat hindlimb: a pharmacological approach

We investigated the source of Ca2+ for the vasoconstriction mediated by alpha1a-adrenoceptors in perfused rat hindlimb in functional studies. The noradrenaline (NA)-induced maximum response was decreased by 92% following perfusion with Ca2+-free medium. Depletion of intracellular Ca2+-stores with repeatedly application of caffeine and NA in Ca2+-free medium resulted in complete abolishment of NA-response. Nifedipine concentration-dependently inhibited NA-contraction with a maximum inhibition of 65%. The residual nifedipine-insensitive response was further inhibited by Cd2+. Following depletion of Ca2+ stores with cyclopiazonic acid in Ca2+ free medium for 30 min, the NA-response obtained by re-admission of Ca2+ was decreased by 80%. However, re-introduction of Ca2+ to NA-treated tissues in Ca2+-free medium without prior treatment with cyclopiazonic acid normalizes the NA-response. These results suggest that the NA-contraction in this preparation is mediated largely via an influx of extracellular Ca2+, of which the majority utilizes L-type calcium channels. Only a small portion of the contractile response to NA is derived from intracellular stores, which probably also play a modulatory role on Ca2+ influx.

Phase II study of liarozole in advanced non-small cell lung cancer

The aim of this phase II study was to investigate the efficacy and tolerability of liarozole, a novel benzimidazole derivative, in non-small cell lung cancer (NSCLC). Liarozole 300 mg twice daily orally was evaluated in 14 patients with stage IIIB and IV NSCLC. 8 patients had received prior treatment with chemotherapy and/or radiotherapy. WHO toxicity grading and response criteria were used. Liarozole was well tolerated. Grade 2 toxicities included alopecia (1 patient), dermatological toxicity (5 patients), dry mouth (2 patients) and nausea and vomiting (2 patients). Leukocytosis was seen in 5 patients, including 2 cases with an elevated white cell count pretreatment. Liarozole was discontinued in 1 patient who developed intolerable progressive pruritus associated with an erythematous rash. No objective tumour response was seen, all 14 patients developing progressive disease within 4 months of commencing treatment. Liarozole was well tolerated but was ineffective as single agent therapy in the management of NSCLC. The side-effect profile was compatible with inhibition of retinoic acid degradation.

Detection of human papillomavirus type 16 DNA and of antibodies to human papillomavirus type 16 proteins in children

We have measured markers of human papillomavirus type 16 (HPV 16) infection in children (1-10 years of age) who were hospitalized for reasons unrelated to papillomavirus infection. Genital and buccal swabs obtained from 79 children were tested for the presence of HPV 16 DNA by PCR. Low-level positivity was found in 34 donors, twice as often in oral than in genital swabs. There was no sex-specific difference, but there was a trend towards a higher positivity rate with young age. Serum antibodies (IgG) were measured by ELISA based on peptides derived from the HPV 16 early proteins E4 (one peptide), E6 (two peptides) or E7 (two peptides) in 75 children and by ELISA based on virus-like particles in 66 children. Low-positivity rates were found for E6 (5.1%), E7 (2.5%) or capsid proteins (1.5%), but 20.3% of the sera reacted with the E4-specific peptide. There was no correlation between sero-positivity and the detection of HPV 16 DNA. In those instances where HPV DNA positivity in young children represents true infection and not environmental contamination, we speculate that this infection is accompanied by low-level virus replication that does not induce a measurable antibody response. Reactivity to the E4 protein is likely due to cross-reacting antibodies directed either against E4 proteins of other HPV types or against unrelated antigens.

[Study on the preventive effect of tea on DNA damage of the buccal mucosa cells in oral leukoplakias induce by cigarette smoking]

In order to study the preventive effect of tea on DNA damage induced by cigarette smoking and to provide further evidence on the protective effects of tea in human cancer, a 6-month, double-blind and randomized placebo-controlled intervention trial was carried out. The effect of tea on micronuclei frequency in exfoliated oral buccal mucosa cells in 36 oral leukoplakias of smokers was investigated. A kind of mixed tea given in an oral dose of 3 g/day and a concentration of 0.1% smeared on mucosa lession three times a day for 3 months and 6 months, significantly decreased the micronuclei formation in exfoliated oral buccal mucosa cells in subjects with oral leukoplakias. In contrast, there was no change in the micronuclei frequency after 6 months in the placebo group. The results indicate that mixed tea may reduce the oral cancer risk by preventing DNA damage in oral leukopiakias induced by cigarette smoking.

Alteration of alpha1-adrenoceptor subtypes in aortas of 12-month-old spontaneously hypertensive rats

Alterations in alpha1-adrenoceptor subtypes in aortas from 12-month-old spontaneously hypertensive rats (SHR) were studied in functional studies and RNase protection assays. The norepinephrine-induced contraction, including maximum response and pD2 values, was not significantly different between the SHR and age-matched Kyoto Wistar (WKY) rats. The pA2 values of the alpha1D-adrenoceptor subtype-selective antagonist BMY7378 (8-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-8-azaspiro(4.5)dec ane-7,9-dionedihydrochloride) were increased from 8.10 +/- 0.12 in WKY rats to 8.45 +/- 0.13 in SHR (P < 0.05). The pA2 values of the alpha1A-adrenoceptor subtype-selective antagonist RS-17053 (N-[2-(2-cyclopropylmethoxyphenoxy)ethyl]-5-chloro-alpha,alpha-dim ethyl-1H-indole-3-ethanamine hydrochloride) were reduced from 8.52 +/- 0.20 in WKY rats to 7.82 +/- 0.18 in SHR (P < 0.05), whereas the pA2 values of the alpha1A/alpha1D-adrenoceptor subtype-selective antagonist WB4101 (2-(2,6-dimethoxphenoxyethyl)-aminomethyl-1,4 benzodioxane) were not significantly different between WKY rats and SHR (9.05 +/- 0.22 versus 9.27 +/- 0.15, P > 0.05). Preincubation of preparations in 50 microM chloroethylclonidine for 30 min irreversibly inhibited the norepinephrine-induced response more profoundly in aortas from SHR than in aortas from WKY rats. The results of RNase protection assays showed that mRNAs for alpha1A- and alpha1B-adrenoceptor subtypes were decreased and that mRNA for the alpha1D-adrenoceptor subtype was increased in aortas from SHR compared with WKY rats. The results suggested that the alpha1A-adrenoceptor subtype was decreased and the alpha1D-adrenoceptor subtype was increased in aortas of 12-month-old SHR.

Effects of micromolar concentrations of Mn, Mo, and Si on alpha1-adrenoceptor-mediated contraction in porcine coronary artery

We studied the effects of trace elements, Mn, Mo, and Si, on vasoconstriction induced by norepinephrine (NE) or electrical field stimulation in isolated porcine right coronary arteries. Alpha1-adrenoceptor (AR) antagonist prazosin dose-despondently suppressed vasoconstriction in response to NE or field stimulation indicating an alpha1-AR mediated response. Mn, Mo, and Si at 0.3-3 micromol/L dose-despondently inhibited NE mediated contraction (all p < 0.05). In contrast, Mn, Mo, and Si at the same concentrations (0.3-3 micromol/L) enhanced the maximal contractile response to field stimulation in a dose-dependent manner (all p < 0.05), but these elements at 10 micromol/L suppressed the vasoconstrictive response. The results indicate that in porcine right coronary arteries, the alpha1-AR-mediated vasoconstriction by NE or electrical field stimulation was affected differently by micromolar concentrations of Mn, Mo, and Si and that the elements might facilitate NE release presynaptically but inhibit the contractile response postsynaptically.

[The antioxidative mechanisms of tea polyphenols in inhibiting tumor promotion by TPA]

In the mouse study, topical application of green tea polyphenols (GTP) significantly inhibited TPA-induced increasing of epidermal ornithine decarboxylase (ODC) and increased the activities of several antioxidant enzymes (CAT, GR and GST). In another in vitro study, when GTP was incubated with TPA and mice polymorphonuclear leukocytes (PMNs), TPA induced hydrogen peroxide formation was markedly suppressed with a dose-dependent relationship. The results suggest that the antioxidative effect of GTP may play an important role in inhibiting tumor promotion.

[Short-term screening of anticarcinogenic ingredients of tea by cell biology assays]

By using a panel of short term cell biology assays, several ingredients of tea (tea pigments, caffeine, tea polysaccharide, tea polyphenols tablet and mixed tea) were screened in order to investigate their anticarcinogenic effects. The cytokinesis block micronuclei test in V79 cells induced by mitomycin, the test of metabolic cooperation between V79 and M cells and the test of growth ability of Hela cells in soft agar were used in the screening. The results showed that the six kinds of tea ingredients tested were effective in the test involved in different stages of carcinogenesis, i.e. initiation, promotion and progression. The effects of mixed tea and tea pigments were the strongest among the ingredients tested.

Comparison of the Ca2+ movement by activation of alpha1-adrenoceptor subtypes in HEK-293 cells

We studied the Ca2+ movement induced by activation of alpha1A-, alpha1B- and alpha1D-adrenoceptor subtypes in transfected HEK-293 cells with the fura-2 probe. All these alpha1-AR subtypes induced both Ca2+ release and Ca2+ entry. The effect on Ca2+ release in alpha1b transfected HEK-293 cells was bigger than that in alpha1a and alpha1d transfected HEK-293 cells, and the effects on Ca2+ entry were the same in alpha1a, alpha1b and alpha1d transfected HEK-293 cells. The Ca2+ entry was inhibited by 1 mM NiSO4, but not by nifedipine. Cyclopiazonic acid (CPA) produced a biphasic Ca2+ signal response in Ca2+ medium, and only induced a transient response in Ca2+-free medium. After depletion of CPA-sensitive Ca2+ pool by 10 microM CPA in Ca2+-free medium, 10 microM adrenaline (Adr) still transiently increased [Ca2+]i in three different alpha1-adrenoceptor subtype transfected HEK-293 cells. However, after depletion of adrenaline-sensitive Ca2+ pool by 10 microM Adr, CPA transiently elevated [Ca2+]i only in alpha1a and alpha1d transfected HEK-293 cells, not in alpha1b transfected HEK-293 cells. U73122, a phospholipase C (PLC) inhibitor, inhibited both Ca2+ release and Ca2+ entry induced by activation of alpha1A alpha1B and alpha1D subtypes in transfected HEK-293 cells. These results suggest that HEK-293 cell line contains two functionally separate intracellular Ca2+ pools, CPA-sensitive and Adr-sensitive pools. Activation of alpha1B-AR stimulates Ca2+ release from both CPA-sensitive and Adr-sensitive Ca2+ pools. Alpha1A and alpha1D subtypes induce Ca2+ release only from Adr-sensitive Ca2+ pool.

ED use of rapid lactate to evaluate patients with acute chest pain

STUDY OBJECTIVE

To test the hypothesis that ED arrival venous lactate levels can be used to diagnose acute myocardial infarction (AMI) and to identify patients with critical illness in the triage of ED patients presenting with chest pain.

METHODS

This was a prospective, double-blind, clinical study in an urban, academic ED. We enrolled a convenience sample of adult patients who had chest pain or cardiac symptoms suggesting AMI that began within 24 hours of presentation. Patients underwent standard medical management for their chest pain. Venous lactate samples were analyzed in the ED on whole blood. An abnormal lactate level of 1.5 mmol/L or higher at the time of arrival was prospectively defined as indicating the presence of acute cardiac disease. ECG findings, levels of creatine phosphokinase (CK) and CK-MB, hospital stay data, and diagnosis of AMI by the cardiology admitting team were recorded.

RESULTS

Of the 129 patients included in the study, 73 had an initial lactate level of 1.5 mmol/L or higher. The mean lactate level (+/- SD) for all patients was 1.8 +/- 1.2 mmol/L. A total of 28 patients (21%) were diagnosed with AMI and had a mean lactate level of 2.2 +/- .7 mmol/L, compared with 1.7 +/- 1.3 mmol/L in those patients who were not diagnosed with AMI (P < .03). The sensitivity of this lactate level in diagnosing AMI was 96% (95% confidence interval [CI], 89% to 100%), and the specificity was 55% (95% CI, 45% to 64%). The negative predictive value of blood lactate was 98% (95% CI, 95% to 100%). Lactate was elevated independent of the duration of chest pain symptoms, with a median time from onset to sampling of 3 hours. Lactate was elevated in patients who either died or required longer than 48 hours of ICU care, compared with survivors not requiring ICU care (4.5 +/- 4.3 mmol/L versus 1.4 +/- .6 mmol/L, respectively; P < .01).

CONCLUSION

The blood lactate concentration obtained on ED arrival identifies those chest pain patients with critical cardiac illness (eg, AMI, severe congestive heart failure [CHF], decompensated arrhythmias). A normal blood lactate result has a high negative predictive value for AMI. An elevated lactate level used in conjunction with ECG and history distinguishes patients with significant myocardium at risk who are likely to benefit from more urgent attention and interventions by the attending physician. Additionally, hyperlactatemia clearly correlates with mortality and the need for ICU management in the acute cardiac patient presenting to the ED.

The antipsychotic drug sertindole is a specific inhibitor of alpha1A-adrenoceptors in rat mesenteric small arteries

We have investigated the adrenergic antagonist effect of the antipsychotic sertindole in rat resistance vessels and in membranes of HEK293 cells transfected with alpha1-adrenoceptors. Segments of rat mesenteric small arteries or rat aorta were mounted on a myograph for isometric tension recording. In mesenteric small arteries, specific alpha1A-adrenoceptor antagonists (5-methyl urapidil and WB-4101 (2-(2,6-dimethoxyphenoxyethyl) aminomethyl-1,4-benzodioxane)) inhibited phenylephrine responses with high affinity (pA2 9.1 and 9.5, respectively). Chlorethylclonidine (alpha1B- and alpha1D-adrenoceptor antagonist) and BMY7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro [4,5] decane-7,9-dione dihydrochloride, alpha1D-adrenoceptor antagonist) had little effect. This indicated that the adrenoceptor subtype in the mesenteric small arteries was of the alpha1A subtype. Sertindole inhibited the phenylephrine response of mesenteric small arteries (pA2 9.0), but had little effect on the phenylephrine response of aorta (which lacks alpha1A-adrenoceptors). The specific action of sertindole on alpha1A-adrenoceptors was supported by experiments with membranes of HEK293 (human embryonic kidney) cells transfected with the alpha1A-, alpha1B- and alpha1D-adrenoceptors. Here, with concurrent incubation, sertindole showed selective competitive inhibition of BE2254 (2-beta(4-hydroxyphenyl)-ethylaminomethyl)-tetralone) binding to alpha1A-adrenoceptors (Ki 8.9), compared to alpha1B-adrenoceptors (Ki 7.1) and alpha1D-adrenoceptors (Ki 6.8). Despite the apparent competitive action sertindole, it was not possible to wash out its antagonist effect within 6 h in the functional phenylephrine concentration-response experiments. Furthermore, in the membranes of HEK293 cells transfected with the alpha1A-adrenoceptors, binding of [125I]BE2254 was reduced by 45% following preincubation with sertindole (1 nM). We conclude that the alpha-adrenoceptors of rat mesenteric small arteries are of the alpha1A-type, and that sertindole is a specific pseudo-irreversible competitive antagonist of this adrenoceptor subtype.

[An experimental study on the effects of lingzhi spore on the immune function and 60Co radioresistance in mice]

Lingzhi spore (2 g.kg-1.d-1, 10 times) was orally administered to mice, and studies were carried out on the carbon clearance, delayed-type skin hypersensitivity (DTH), antibody hemagglutinin value and spleen weight. The results showed that Lingzhi spore could increase the immune function, inhibit the reduction of white blood cells and raise the survival rate of mice after they were radiated by 870 rad 60Co.

Alterations of cardiac alpha 1-adrenoceptor subtypes in hypothyroid rats

1. Alterations in the cardiac alpha 1-adrenoceptor and its subtypes in hypothyroid rats were studied by radioligand binding assays and reverse transcription-polymerase chain reaction (RT-PCR). Hypothyroidism was created by feeding rats with 0.2% 2-thiouracil solution instead of daily drinking water for 20 days. 2. The density of cardiac alpha 1-adrenoceptors (Bmax) was increased from 67.5 +/- 4.3 fmol/mg in control rats to 81.1 +/- 7.2 fmol/mg (P < 0.05) in hypothyroid rats. 3. Compared with control rats, in hypothyroid rats the percentages of high-affinity sites for (+)-niguldipine and 5-methylurapidil were increased from 13.8 +/- 5.6 and 31.9 +/- 6.3%, respectively, to 24.9 +/- 7.3 and 45.5 +/- 2.4%, respectively (both P < 0.05), while those for BMY7378 were decreased from 37.2 +/- 8.9 to 23.8 +/- 8.4% (P < 0.05), respectively. The percentage of high-affinity sites for WB4101 was not significantly different in control and hypothyroid rats (43.3 +/- 9.1 and 39.4 +/- 3.6%, respectively). 4. Reverse transcription-PCR experiments revealed that the steady state levels of mRNA for alpha 1A- and alpha 1B-adrenoceptors were increased, while those for alpha 1D-adrenoceptor were decreased in the hearts of hypothyroid rats. 5. The concentration-contraction response curves for noradrenaline in the presence of a beta-adrenoceptor antagonist in control and hypothyroid rats showed that the maximal response was reduced from 344 +/- 58 to 200 +/- 23 mg, respectively (P < 0.05). 6. The data suggest that in hypothyroid rats the total number of cardiac alpha 1-adrenoceptors is increased. The change is subtype-selective, with levels of alpha 1A- and alpha 1B-adrenoceptors being increased and levels of alpha 1D-adrenoceptors being reduced. Furthermore, the positive inotropic response mediated by alpha 1-adrenoceptors is reduced in hypothyroid rats.

Differential expression of two functional serine/threonine protein kinases from soybean that have an unusual acidic domain at the carboxy terminus

Two soybean cDNA clones, SPK-3 and SPK-4, encoding putative protein kinases were isolated and characterized. Both cDNAs encoded approximately 40-kDa serine/threonine kinases with unusual stretches of acidic amino acids in their carboxy-terminal regions, which are highly homologous to PKABA1 from wheat and ASKs from Arabidopsis. These kinases are encoded by one- or two-copy genes in the soybean genome. Notably, SPK-3 and -4 showed different patterns of expression in various soybean tissues. SPK-3 is highly expressed in dividing and elongating tissues of young seedlings but relatively weakly in tissues of mature plants. In contrast, SPK-4 showed relatively high and constitutive expression in all the tissues examined except for leaf tissues of mature plants. Although various stressors, such as dehydration and high salinity, increased the expression of both genes, the induction kinetics were different. The two genes also differed in their response to abscisic acid (ABA). SPK-3 was induced but SPK-4 was not affected by exogenously supplied abscisic acid. In accordance with these expression data analysis of the activity of a chimeric SPK-3 promoter::beta-glucuronidase (GUS) reporter gene by transient expression in tobacco leaves confirmed the inducibility of SPK-3 by salt and ABA. Polyclonal antibodies raised against a recombinant SPK-4 protein produced in Escherichia coli specifically recognized both recombinant SPK-3 and -4 proteins. Kinase assays using affinity-purified SPK-4/ antibody complexes with crude soybean extracts as substrate identified specific phosphorylation of two 41 and 170 kDa soybean proteins that were phosphorylated on serine residues. Taken together, our results suggest that SPK-3, and/or SPK-4 are functional serine protein kinase(s). Furthermore, SPK-3 and -4 may play different roles in the transduction of various environmental stresses.

Characterization of subtype of alpha1-adrenoceptor mediating vasoconstriction in perfused rat hind limb

The subtype of alpha1-adrenoceptor mediating the exogenous noradrenaline-induced vasopressor response in perfused rat hind limb was determined by functional measurements and radioligand binding assays. The potencies (pA2 values) of alpha1A-adrenoceptor-selective antagonists, RS-17053 (N-[2-(2-cyclopropylmethoxy-phenoxy) ethyl]-5-chloro-alpha,alpha-dimethyl-1H-indole-3-ethanamine hydrochloride), WB 4101 (2-(2,6-dimethoxyphenoxyethyl) aminomethyl-1,4 benzodioxane), 5-methyl-urapidil, and the alpha1D-adrenoceptor-selective antagonist, BMY 7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspirol[4.5]de cane-7,9-dione), to inhibit the noradrenaline-induced vasopressor response determined by Schild plot were 9.47 +/- 0.21, 9.48 +/- 0.19, 8.10 +/- 0.27 and 6.66 +/- 0.14, respectively, with no slope significantly different from unity. The affinities (K(i) values) of these antagonists were determined by displacement of 125I-BE 2254 (2-beta(4-hydroxyphenyl)-ethylaminomethyl)-tetralone) binding from the cloned alpha1a-, alpha1b-, alpha1d-adrenoceptor, stably expressed in human embryonic kidney (HEK) 293 cells. The pA2 values of the above antagonists correlated well with the binding K(i) values only for alphaIA-adrenoceptors (r = 0.93), but not for alpha1B-adrenoceptors (r = 0.51) and alpha1D-adrenoceptors (r = 0.13). The concentration-vasopressor response curve for noradrenaline was not significantly affected by pretreatment with 50 microM chloroethylclonidine for 30 min. The results suggest that only alpha1A-adrenoceptors mediate the noradrenaline-induced vasopressor response in perfused rat hind limb.

Alterations of mRNA levels of alpha 1-adrenoceptor subtypes with maturation and ageing in different rat blood vessels

1. Alterations of mRNA levels of alpha 1-adrenoceptor subtypes during maturation and ageing were determined by reverse transcription-polymerase chain reaction (RT-PCR) in aortae and renal, pulmonary and mesenteric arteries isolated from 3, 12 and 24-month-old rats. 2. The steady state levels for alpha 1A-, alpha 1B- and alpha 1D-adrenoceptors in aorta declined with maturation and ageing. In renal artery there was a decrease in mRNA for the alpha 1B-adrenoceptor in aged rats. However, in mesenteric and pulmonary arteries there were no changes in mRNA levels for the three subtypes of alpha 1-adrenoceptors as a result of maturation and ageing. 3. The results suggest that expression of alpha 1-adrenoceptors is changed heterogeneously in different blood vessels during maturation and ageing in rats.

[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.

compound A induces sister chromatid exchanges in Chinese hamster ovary cells

BACKGROUND

Compound A [CF2 = C(CF3)OCH2F], a degradation product of sevoflurane [(CF3)2CHOCH2F], is a vinyl ether and may be an alkylating agent. Thus it is a potential genotoxin.

METHODS

The capacity of compound A to produce sister chromatid exchanges was measured in Chinese hamster ovary cells with and without metabolic activation. Concentrations of 11 to 468 ppm compound A were applied for 2 h, the Chinese hamster ovary cells were incubated for a further 34 h in the presence of bromodeoxyuridine, and then colcemid was added to produce arrest in metaphase. Coded slides of cells were examined blindly, and 50 chromosome spreads were counted for each test concentration.

RESULTS

The lowest concentration of compound A applied without metabolic activator (27 ppm) significantly increased (P < 0.001) sister chromatid exchanges, and increasing concentrations of compound A increased the incidence of exchanges. Metabolic activation did not increase the incidence of exchanges.

CONCLUSIONS

Compound A increases sister chromatid exchanges at concentrations (27 ppm) obtained in low-flow systems when sevoflurane is used at concentrations approximating minimum alveolar concentration.

[Study of environmental pollution and damage of cytogenetic materials in urban residents]

Recently, epidemiologic data have indicated that the number of deaths caused by malignant tumor presented a significantly rise in Beicun countryside of Datong city. In order to understand the causes of high incidence of cancer, factors were investigated and analysed related to air, river water, drinking water, vegetables and human serum. Results showed that Benzo (a)-pyrene (Bap), total suspended particulates (TSP) in air, nitrate, nitrite in drinking water and vegetables were all significantly higher in Beicun countryside region than those in controlled countryside region, respectively (P < 0.01-P < 0.001). The micronuclei (MN) and berration nucleus (AN) rates of cultured lymphocytes were significantly higher while cpm value of unscheduled DNA synthesis (UDS) test were significantly lower than those in controlled region among residents in Beicun countryside region, respectively (P < 0.01-P < 0.001). The micronuclei, abrerration nucleus rates and cpm value of cultured lymphocytes among residents in Beicun countryside were strongly correlated with Bap, TSP, nitrite and nitrate contents in determination samples. Our results suggest that the air and water source under serious pollution may serve as an important factor causing cytogenetic damage among residents and cancer death rise in Beicun countryside.

Screening of anticarcinogenic ingredients in tea polyphenols

A batch of short-term tests were used to test the antimutagenic activities of Chinese green tea water extract (TWE), tea polyphenols (TP), and tea catechins (EGCG, ECG, EGC, EC). In the V79 cell forward gene mutation and V79 cell cytokinesis-block micronuclei tests, all samples showed significant inhibitory effects on mitomycin, which indicates their effects on the initiation stage of chemical carcinogenesis. However, none of the catechins and TP had effects as strong as the TWE on the basis of their relative contents in tea. Of the four catechins, ECG and EGCG were the most potent. Using the V79 cell metabolic co-operation test as an indicator for the promotion stage, TWE and TP showed weak inhibitory effects and the individual catechins showed much stronger inhibition. The test samples also showed non-specific inhibitory effects on HeLa cell growth in soft agar, which was designed to test their effects on the progression stage.

Increase of calcitonin gene-related peptide (CGRP) release and mRNA levels in endotoxic rats

Previously we showed that calcitonin gene-related peptide (CGRP) is released into the circulation during pathogenesis of septic shock in humans and endotoxicosis in rats and pigs. The present study examines the changes of both CGRP release and synthesis during endotoxicosis in rats. Endotoxin was administered as a bolus (5 mg/kg,i.v.) to rats lightly anesthetized with ether. Blood samples and lumbar dorsal root ganglia (DRG), neuronal cell bodies synthesizing CGRP, were taken from rats at 0, .5, 3, or 8 h after endotoxin administration. CGRP levels in plasma and the steady-state levels of mRNA for CGRP in DRG were determined by methods of radioimmunoassay and semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR), respectively. Endotoxin elevated plasma CGRP by 62%, but not mRNA at .5 h. Endotoxin increased plasma CGRP by 142% and CGRP mRNA in DRG by 36% at 3 h, and further increased plasma CGRP by 216% and CGRP mRNA in DRG by 88% at 8 h. The data suggest that both CGRP expression and release in sensory nerves are increased during development of endotoxicosis in rats. CGRP synaptic transmission may be maintained during the course of endotoxicosis in rats. DRG undergo an elevation of CGRP expression in response to endotoxicosis, presumably as an adaptation of CGRP release during the inflammation. CGRP, because of its extremely high potency in hypotensive, tachycardiac and immunosuppressive effects, may play an important role in the pathogenesis of septic shock.

Pediatric carve outs. The use of disease-specific conditions as risk adjusters in capitated payment systems

OBJECTIVE

To address the issue of adverse selection in capitated payment systems by developing a list of disease-specific pediatric conditions (i.e., "carve outs") to be considered for separate reimbursement.

DESIGN

A descriptive study using a large Medicaid database.

INTERVENTION

With the use of fiscal year 1993 Washington State Medicaid cost data for 302,240 pediatric patients, a list of disease-specific carve outs was developed to meet the following criteria: high cost, low variability in cost, and association with a large proportion of medical spending.

RESULTS

Six-hundred seventy-three patients (0.2%) in the database had annual costs totaling $25,000 or more. Ten percent of the cases accounted for approximately two thirds of spending, while the least expensive 70% of cases made up only 15% of the expenditures. Prematurity and complications of prematurity, neoplasms, congenital heart disease, organ transplantations, congenital anomalies, and respiratory problems were general categories of disease that met our criteria for a carve out. The association of a major surgical procedure with a diagnosis increased the predictive accuracy for high cost.

CONCLUSION

Lists of disease-specific carve outs such as this one can be used by Medicaid plans and other insurers who are concerned about risk selection to identify conditions for separate reimbursement in capitated payment systems.

[Splenic artery embolization for the treatment of traumatic splenic rupture]

We used splenic artery gelfoam embolization to save the spleen Seldinger's method in 20 patients with traumatic rupture of the spleen. All patients had the spleen reserved by single embolizing hemostasis satisfactorily. We delineate the method, clinical value, indication and experience of embolism-hemostasis in detail.

Induction of ICE and inhibition of c-fos, jun D and zif 268 in 12-month old spontaneously hypertensive rats

A semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) assay was used to examine ICE, c-fos, jun D and zif 268 mRNA expression in the aortic and renal artery of 12-month old SHRs and wistar rats. Using this assay system, it was observed that the levels of aortic and renal artery expression of ICE were markedly higher in SHRs than in wistar rats. In contrast, the aortic and renal artery expression of immediate early genes (IEGs), c-fos, jun D and zif 268, were significant lower in SHRs than in wistar rats. Thus, our results suggest that differential regulation of death gene ICE and IEGs such as c-fos, jun D and zif 268 might be involved in the mechanism of pathogenesis of hypertension.

Serologic association between human papillomavirus type 16 infection and esophageal cancer in Shaanxi Province, China

BACKGROUND

The existence of large geographic variations in the prevalence of esophageal cancer in some countries, such as China, indicates that environmental risk factors may be important in the development of this disease. Some studies have implicated genital-mucosal strains of human papillomaviruses (HPVs) in the etiology of this cancer.

PURPOSE

We conducted a case-control study in Shaanxi Province, China, an area with a population at high risk for esophageal cancer, to assess the association of this disease with infection by HPV type 16 (HPV16), the most common cancer-associated genital-mucosal HPV type.

METHODS

Ninety individuals with esophageal cancer and 121 cancer-free control subjects were identified among the patients in two hospitals in Xi'an, Shaanxi Province. The control subjects were matched to the case patients on the basis of age and sex. Blood specimens were drawn from all study subjects, and serum was isolated by routine methods. The presence of HPV16 antibodies in serum samples was determined by use of an enzyme-linked immunosorbent assay (ELISA) that used baculovirus-derived HPV16 virus-like particles as the antigen. A similar ELISA that used bovine papillomavirus type 1 (BPV1) virus-like particles as the antigen controlled for the specificity of HPV16 seroreactivity. Data from the HPV16 and the BPV1 assays were normalized with respect to results obtained in each assay with a control serum of known HPV16 seroreactivity. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to examine the association between HPV16 seroreactivity and esophageal cancer. Reported P values are two-sided.

RESULTS

The mean seroreactivity to HPV16 virus-like particles was significantly higher for the cancer patients than for the control subjects (mean value +/- standard deviation = 0.85 +/- 0.22 versus 0.74 +/- 0.18; P<.0001). When the cancer patients and control subjects were compared by sex and age groups, the differences in mean seroreactivity remained statistically significant. The difference in mean seroreactivity to BPV1 virus-like particles between cancer patients and control subjects was not statistically significant (0.81 +/- 0.28 versus 0.88 +/- 0.32; P = .12); this result was not altered when sex and age groups were compared. By use of a cutoff point for HPV16 seropositivity that was established in studies of cervical neoplasia, 24% of the cancer patients were seropositive compared with 7% of the control subjects, yielding a sex- and age-adjusted OR of 4.5 (95% CI = 1.8-11.9). In general, the OR for esophageal cancer increased with increasing HPV16 seroreactivity.

CONCLUSIONS AND IMPLICATIONS

HPV16 infection may be a risk factor for esophageal cancer. Further studies of the association between HPV16 infection and the incidence of esophageal cancer are needed.

Quantification of mRNAs for three alpha 1-adrenoceptor subtypes in rat aorta by solution hybridization

We used solution hybridization to quantify mRNAs for alpha 1A-, alpha 1B-and alpha 1D-adrenoceptor(AR) in rat aortae. The results showed that the mRNA for alpha 1A-, alpha 1B- and alpha 1D-AR was 0.28 +/- 0.03 fmol, 0.35 +/- 0.03 fmol and 0.82 +/- 0.09 fmol, respectively, in 40 micrograms total RNA extracted from rat aorta. The dominant expression of alpha 1D-AR further support the recent findings that alpha 1D-AR is a major functional receptor subtype of AR in rat aorta.

Rapid nitric oxide- and prostaglandin-dependent release of calcitonin gene-related peptide (CGRP) triggered by endotoxin in rat mesenteric arterial bed

1. Our objective was to determine whether endotoxin (ETX) could directly trigger the release of calcitonin gene-related peptide (CGRP) from perivascular sensory nerves in the isolated mesenteric arterial bed (MAB) of the rat and to determine whether nitric oxide (NO) and prostaglandins (PGs) are involved. 2. ETX caused time- and concentration-dependent release of CGRP, and as much as a 17 fold increase in CGRP levels in the perfusate at 10-15 min after the administration of ETX (50 micrograms ml-1). 3. CGRP-like immunoreactivity in the perfusate was shown to co-elute with synthetic rat CGRP by reverse-phase h.p.l.c. 4. Pretreatment of MAB with capsaicin or ruthenium red inhibited ETX-induced CGRP release by 90% and 71%, respectively. ETX-evoked CGRP release was decreased by 84% during Ca2(+)-free perfusion. 5. The release of CGRP evoked by ETX was enhanced by L-arginine by 43% and inhibited by N omega-nitro-L-arginine (L-NOARG) and methylene blue by 37% and 38%, respectively. L-Arginine reversed the effect of L-NOARG. 6. Indomethacin and ibuprofen also inhibited the ETX-induced CGRP release by 34% and 44%, respectively. No additive inhibition could be found when L-NOARG and indomethacin were concomitantly incubated. 7. The data suggest that ETX triggers the release of CGRP from capsaicin-sensitive sensory nerves innervating blood vessels. The ETX-induced CGRP release is dependent on extracellular Ca2+ influx and involves a ruthenium red-sensitive mechanism. Both NO and PGs appear to be involved in the ETX-induced release of CGRP in the rat mesenteric arterial bed.

[Relationship between expression of P21ras and cellular DNA in pleomorphic adenoma of lacrimal gland]

BACKGROUND

The pleomorphic adenoma is the most frequent tumor of the human lacrimal gland comprising about 50% of the epithelial tumors of this organ. Although being benign, local recurrences can occur when the first removal was incomplete and malignant transformation is also not in frequent. It is well known that many sorts of cellular oncogene products are involved in the initiation, promotion and progression of the human neoplasm. Our purpose was to know whether there is abnormal expression of P21ras in pleomorphic adenoma.

METHODS

We have undertaken a study of the expression of P21ras in 5 normal tissues and 32 pleomorphic adenoma of lacrimal gland by immunohistochemical means using the monoclone antibody F-132-62 and the nuclear DNA content in the tumor was assayed by image analysis technique.

RESULTS

Normal tissues of lacrimal gland were negative, 12 tumors were stained positively with the antibody. The DNA content of 14 cases of tumor was increased. Their DNA ploidy distribution pattern showed two or several peaks. Good correlation has been found between the expression of P21ras and DNA ploidy distribution pattern, the DNA ploidy distribution pattern of tumor which expressed p21ras showed mainly two or several peaks. P< 0.05.

CONCLUSIONS

The result of our studies may suggest that there are increased expression of p21ras in pleomorphic adenoma and the expression of p21ras is related to the promotion and progression of pleomorphic adenoma of lacrimal gland.

Endogenous inotropic factor-induced endothelium-dependent relaxation of vascular smooth muscle

1. Possible contractile or relaxation effects of an endogenous inotropic factor (EIF) isolated and purified from porcine heart left ventricle were examined in rat isolated aortic ring preparations. 2. EIF induced a dose-dependent relaxation of the rat isolated aortic ring preparation pre-contracted with 0.4 microM phenylephrine (PE); 200 microliters (in 5 ml bath) of EIF caused relaxation of aortic rings by as much as 67.4 +/- 4.5%. In another set of experiments, in the presence of 100 microliters EIF, the PE concentration-response contractile curve shifted to the right, the maximal contractile force was reduced by as much as 32.8% and the EC50 of PE increased from 0.2 to 0.3 microM. 3. The relaxation effect of EIF was demonstrated to be endothelium-dependent. Additional experiments demonstrated that EIF-induced relaxation in an isolated aortic ring could be inhibited by 2 microM NG-nitro-L-arginine methyl ester, a nitric oxide synthase inhibitor, suggesting the involvement of nitric oxide in EIF-induced relaxation of the muscle. 4. Atropine (0.2 microM) or indomethacin (10 microM) had no significant effect on EIF-induced relaxation. 5. These data suggest that EIF, a novel endogenous inotrope from porcine myocardium, also acts as an endothelium-dependent vasodilator substance mediating relaxation in the rat isolated aorta mainly by release of nitric oxide. The possibility of EIF acting through muscarinic receptor and the involvement of prostacyclin were excluded.