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Biomedical subjects

W Guo

Publications and source records attributed to W Guo.

At least 253 records · Page 14Linked to original sources
PubMed1995

[Protective effect of semen Ziziphi spinosae on superoxide dismutase reduction in mice with endotoxin fever].

An animal model with decreasing SOD was established by fever from intravenous injection of endotoxin. The SOD level was measured by RIA in the animal serum and liver tissues. The results indicated that the SOD level of the model group was obviously lower than that of the normal group (P < 0.05), but the level of the group treated with Semen Ziziphi Spinosae was higher than that of the model group. The study shows that Semen Ziziphi Spinosae can protect mice with endotoxin fever from SOD decrease.

Animals↗
PubMed1995

Comparison of plasma cytokine levels in rats subjected to superior mesenteric artery occlusion or hemorrhagic shock.

The overall goal of this study was to compare the effects of systemic hypotension (hemorrhagic shock) versus local gut ischemia (superior mesenteric artery (SMA) occlusion) on cytokine production and bacteria/endotoxin translocation. Sham or actual SMA occlusion led to an increase in tumor necrosis factor (TNF), which was greatest at the end of the occlusion period, while the IL-6 response peaked 3 h post-SMA occlusion. The TNF and IL-6 response after hemorrhagic shock differed from that observed after SMA occlusion in that the peak response occurred later and was of lower magnitude (p < .05). Although the animals subjected to SMA occlusion had a significantly increased incidence of bacterial translocation to both the mesenteric lymph nodes and systemic organs compared to rats subjected to hemorrhagic shock, in neither group was the blood level of endotoxin elevated and there was no association between bacterial translocation and cytokine levels. These results suggest that different models of intestinal ischemia have different cytokine profiles and that the early TNF response associated with SMA occlusion model is primarily due to the laparotomy.

Animals↗
PubMed1994

An unusual member of the nuclear hormone receptor superfamily responsible for X-linked adrenal hypoplasia congenita.

X-linked adrenal hypoplasia congenita is a developmental disorder of the human adrenal gland that results in profound hormonal deficiencies and is lethal if untreated. We have isolated the gene responsible for the disease, DAX-1, which is deleted or mutated in X-linked adrenal hypoplasia patients. DAX-1 encodes a new member of the nuclear hormone receptor superfamily displaying a novel DNA-binding domain. The DAX-1 product acts as a dominant negative regulator of transcription mediated by the retinoic acid receptor.

Adrenal Insufficiency↗
PubMed1994

Characterization and ultrastructural localization of a novel 90-kDa protein unique to skeletal muscle junctional sarcoplasmic reticulum.

Monoclonal antibodies were used to identify and characterize a novel 90 kDa protein that was specifically localized to the junctional sarcoplasmic reticulum of rabbit skeletal muscle. Biochemical experiments show that the 90 kDa protein is an integral membrane protein of the junctional face membrane and is a substrate for the intrinsic protein kinase in triads. Immunofluorescence staining of serial transverse sections of skeletal muscle with a monoclonal antibody to the 90 kDa protein showed preferential staining of type II "fast" fibers. Specific labeling was confined to the interphase between the A- and I-bands, where the triad structure is localized. Immunoelectron microscopical labeling further indicates that the 90 kDa protein, like the ryanodine receptor/Ca(2+)-release channel and triadin, is confined to the terminal cisternae of the sarcoplasmic reticulum. Western blot analysis with a combination of monoclonal antibodies against the 90 kDa protein shows that it is specifically expressed in skeletal muscle but not in cardiac muscle or brain. Similarly, specific immunofluorescence labeling to the 90 kDa protein was not detected in ventricular myocytes or vascular smooth muscle cells. The junctional localization and phosphorylation of this protein suggest that it may play an important regulatory or structural role in the skeletal muscle triad junction.

Animals↗
PubMed1994

Prevention of esophageal cancer: the nutrition intervention trials in Linxian, China. Linxian Nutrition Intervention Trials Study Group.

In Linxian China, the esophageal/gastric cardia cancer mortality rates are among the highest in the world. There is suspicion that the population's chronic deficiencies of multiple micronutrients are etiologically involved. We conducted two randomized, placebo-controlled nutrition intervention trials to test the effects of vitamin and mineral supplements in lowering the rates of esophageal/gastric cancer. In the first trial, the dysplasia trial, 3318 adults with a cytological diagnosis of esophageal dysplasia received daily supplementation with 26 vitamins and minerals in doses typically 2-3 times the United States Recommended Daily Allowances, or placebos, for 6 years. The second trial, the general population trial, involved 29,584 adults and used a one-half replicate of a 2(4) factorial experimental design which tested the effects of four combinations of nutrients: A, retinol and zinc; B, riboflavin and niacin; C, vitamin C and molybdenum; and D, beta-carotene, vitamin E, and selenium. Doses for these daily supplements ranged from 1 to 2 times the United States Recommended Daily Allowances, and the different vitamin/mineral combinations or placebos were taken for a period of 5.25 years. As part of the general population trial, and end-of-intervention endoscopy survey was carried out in a small (1.3%) sample of subjects to see if supplementation affected the prevalence of dysplasia and early cancer. Herein we review the methods of these trials and the results of the endoscopic survey. Fifteen esophageal and 16 gastric cancers were identified in endoscopic biopsies from the 391 subjects evaluated from two villages, and nearly all were asymptomatic. No significant reductions in the prevalence of esophageal or gastric dysplasia or cancer were seen with any of the four supplement groups. However, the prevalence of gastric cancer among participants receiving retinol and zinc was 62% lower than those not receiving those supplements (P = 0.09), while participants receiving beta-carotene, vitamin E, and selenium had a 42% reduction in esophageal cancer prevalence (0.34). We have reported separately that cancer mortality over the entire 5.25-year period was significantly reduced among those receiving beta-carotene, vitamin E, and selenium. The findings from the overall trial and the endoscopic sample offer a hopeful sign and should encourage additional studies with these agents in larger numbers of subjects.

Adult↗
PubMed1994

Splenic response to silicon drain material following intraperitoneal implantation.

To study the splenic response to intraperitoneal biomaterials, 100% silicon rubber drain fragments were intraperitoneally implanted in the rat. Four days after implantation, specimens of the spleen and implanted rubber fragment were retrieved and subjected to scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis (EDX). In SEM, macrophages with membrane fusion and cytoplasmic spreading were noted on the surfaces of implanted rubber fragments. Specimens of the spleen from animals with implants showed light 3-10-microns structures that were not observed in those without implants. EDX revealed the presence of silicon both in the rubber fragment and in the spleen of the implanted animals. Both light microscopy and transmission electron microscopy showed a large number of particles inside giant cells of the spleen. The present study demonstrated an active transport of rubber fragments containing silicon from the peritoneal cavity to the spleen by adherent macrophages, reflecting a splenic response to intraperitoneal implantation of biomaterials. The modes of silicon rubber degradation and transportation remain to be elucidated.

Animals↗
PubMed1994

Bacterial translocation after intraperitoneal implantation of rubber fragments in the splenectomized rat.

The aim of the present study was to determine the influence of splenectomy on the incidence of enteric bacterial translocation in rats with intraperitoneal rubber drain implantation. Male Sprague-Dawley rats (250-300 g) underwent splenectomy or sham operation 7 days prior to the intraperitoneal implantation of rubber drain fragments (7 cm2). Bacterial translocation was measured 2 days after rubber drain implantation. The incidence of bacterial translocation was significantly higher in the group with intraperitoneal rubber drain implantation plus sham splenectomy than in the groups with sham splenectomy plus sham implantation, splenectomy plus sham implantation or splenectomy plus rubber drain implantation. An increase in ileal permeability of 125I-human serum albumin was induced by intraperitoneal rubber drain implantation and ameliorated by splenectomy. Splenectomy also improved the impaired intestinal motility induced by intraperitoneal rubber drain implantation. Histological examination revealed a preserved normal mucosal architecture in splenectomized rats. Thus, splenectomy reduced the rate of enteric bacterial translocation induced by intraperitoneal biomaterial implantation.

Animals↗
PubMed1994

Effect of maternal ethanol intake on fetal rabbit gastrointestinal development.

Maternal ingestion of alcohol is believed to be one factor that greatly influences the development of intrauterine growth retardation (IUGR) and postnatal growth failure. The present study was undertaken to determine whether maternally ingested alcohol adversely affects fetal growth and intestinal mucosal function. Five time-mated New Zealand white rabbit does were given ethanol intravenously (ETH group) (30% vol/vol; 1.0 g/kg/d) on gestational days (GD) 15 through 29 (term, 31 days). Two other rabbits received the same dose of ethanol. Maternal, fetal, and amniotic fluid alcohol levels were measured on GD 24. Four control rabbits (SH group) received normal saline (25 mL, intravenously). At term, the animals were delivered by cesarean section and killed. Seventeen of the 42 ETH fetuses survived the study period (43%); all 24 SH fetuses survived. On GD 24, within 60 minutes after maternal ethanol infusion, the fetal blood alcohol concentration (BAC) increased to 153 +/- 1.97 mg/dL (v maternal, 179 +/- 1.75 mg/dL); the amniotic ethanol level increased to 46 +/- 1.32 mg/dL. Birth weight was lower in the ETH group (46.88 +/- 2.21 g) than in the SH group (55.78 +/- 1.80 g) (P < .01). Disaccharidase activity, an indicator of intestinal mucosal function, showed that lactase activity (per milligram of protein) was significantly lower in ETH fetuses (2.60 x 10(-2) +/- 0.22 UE/mg) than in SH fetuses (3.50 x 10(-2) +/- 0.25 UE/mg) (P = .01); maltase activity and protein content were not affected significantly. This report provides the first description of the adverse effects of maternal alcohol ingestion on the small intestinal mucosal function of the fetal rabbit.

Alcohol Drinking↗
PubMed1994

A nested case-control study of oesophageal and stomach cancers in the Linxian nutrition intervention trial.

BACKGROUND: Rates of oesophageal/gastric cardia cancer in Linxian, a rural county in north central China, are among the world's highest, but the risk factors are not well understood. METHODS: A nested case-control study of oesophageal and stomach cancers was conducted within a cohort of 29,584 adults who participated in a randomized nutrition intervention trial. Information on participant characteristics collected during interviews before the trial began was compared between individuals who subsequently developed cancers of the oesophagus (N = 640) or stomach (N = 539), mainly cardia, and individually matched controls (control/case ratio = 5). Analyses were performed separately for oesophageal and stomach cancers using conditional logistic regression. RESULTS: For oesophageal cancer, tobacco smoking was associated with a significantly elevated risk, with a twofold increase among long-term smokers. Alcohol consumption was uncommon and not related to risk. High consumption of eggs or fresh vegetables was associated with 20% reductions in risk, and risk significantly declined as pre-trial body mass index (BMI), an indicator of long-term nutritional status, increased. No increases in risk were associated with intake of pickled vegetables or mouldy foods, although consumption levels at the start of the trial were low. Excess risks of 40-80% were found among individuals who had reported a history of cancer, notably of the oesophagus and stomach, in parents or sibs. For stomach cancer, only low BMI was significantly associated with elevated risk. CONCLUSIONS: This study indicates that several risk factors for oesophageal and stomach cancers in Linxian, including smoking, nutritional deficiency, and familial cancer occurrence, resemble those in other areas of the world and contribute partly to the remarkably elevated rates in this area of China.

Adult↗
PubMed1994

Abdominal rubber drain piece aggravates intra-abdominal sepsis in the rat.

Biomaterials in the peritoneal cavity disrupt the physiology of the host and may cause bacterial translocation. The current study was performed to determine whether biomaterials exacerbate intra-abdominal infections. Adult male rats were divided into four groups: group 1, celiotomy+intraperitoneal (i.p.) saline; group 2, celiotomy+i.p. Escherichia coli (3 x 10(8) cfu); group 3, i.p. rubber+i.p. saline; and group 4, i.p. rubber+i.p. E. coli (3 x 10(8) cfu). Twelve h after the challenge, enteric bacterial translocation, bacterial population levels in the cecum and serum levels of IL-6 and TNF were measured. Bacterial translocation to mesenteric lymph nodes and the liver was observed in animals from groups 2 and 3, but significantly increased in group 4 with a concomitant elevation of serum levels of TNF and IL-6, as compared with group 1. Histological examination revealed a more pronounced inflammatory reaction in the peritoneum and distal ileum in group 4 than in groups 2 and 3. These results suggest that the presence of rubbers in the peritoneal cavity aggravates intra-abdominal sepsis.

Abdomen↗
PubMed1994

Orally administered phospholipids inhibit abdominal rubber-drain-induced bacterial translocation in the rat.

In order to determine the influence of phospholipid on abdominal biomaterial-induced bacterial translocation (BT), phsophatidylcholine (PC) or phosphatidylinositol (PI) was administered orally or intraperitoneally in rats with intraperitoneal implantation of 7-cm2 rubber drain pieces. Two days after surgery, the incidence of translocation to mesenteric lymph nodes and liver significantly decreased, the adherence of 3H-labeled Escherichia coli to the ileal mucosa was significantly inhibited and the phagocytic and bactericidal capacity of peritoneal macrophages increased in animals with PC or PI administered orally, but not intraperitoneally, as compared with rats without phospholipid administration. Scanning electron microscopy revealed a coating layer on the surface of the intestinal mucosa in phospholipid-gavaged rats. Thus, the results in the present study imply that oral, but not intraperitoneal, PC of PI administration reduces enteric BT induced by intraperitoneal drain implantation.

Administration, Oral↗
PubMed1994

(S)-linalyl, 2-phenylethyl, and benzyl disaccharide glycosides isolated as aroma precursors from oolong tea leaves.

Three glycosides, 6-O-beta-D-xylopyranosyl-beta-D-glucopyranosides (beta-primeverosides) of the aroma constituents, linalool, 2-phenylethanol, and benzyl alcohol, were isolated as aroma precursors from the tea leaves (Camellia sinensis var. sinensis cv. Shuixian and Maoxie, cultivars for oolong tea). The isolation was guided by acid or enzymatic hydrolysis, and subsequent GC and GC-MS analyses. The linalyl glycoside is the first example of naturally occurring (S)-linalyl beta-primeveroside.

Benzyl Alcohols↗
PubMed1994

Water-soluble ethylhydroxyethyl cellulose: a new agent against bacterial translocation from the gut after major liver resection.

BACKGROUND: Bacterial translocation from the gut to extraintestinal sites has been demonstrated as a mechanism explaining bacterial infectious complications after various insults. METHODS: To explore the potential therapeutic value of water-soluble ethylhydroxyethyl cellulose (EHEC). Its effects on macrophage phagocytic capacity, bacterial adherence on the intestinal surface, and bacterial growth were evaluated both in vivo and in vitro. RESULTS: Preoperative administration of EHEC reduced the incidence of bacterial translocation from the gut to mesenteric lymph nodes and blood and prevented overgrowth by enteric bacteria after 70% or 90% hepatectomy. Uptake of macrophages harvested from blood decreased after intravenous administration of EHEC. EHEC diminished the otherwise increased bacterial adherence on the intestinal surface induced by major liver resection. EHEC in bacterial cultures for over 1 h was capable of inhibiting bacterial growth and delaying bacterial DNA synthesis in vitro. CONCLUSIONS: The present study indicates that EHEC could be a potential agent for the prevention of gut-origin sepsis.

Animals↗
PubMed1994

[Comparison of antitumor activity of tumor draining lymph node lymphocytes and peripheral blood lymphocytes in human oral cancer].

The in vitro and in vivo antitumor activity between DNL and autologous LAK cells was compared. The results showed that DNL cells activated in vitro by rIL-2 exhibited higher cytotoxicity to Tca 8113 cells than the same patient's LAK cells (75% and 36%, respectively). According to Winn's method, the inhibition rates of subcutaneously transplanted Tca cells in mice were 74% and 42% respectively. There was significantly difference in the antitumor activity in vitro and in vivo between two groups (P < 0.05), indicating that DNL cells which are more available are more practicable for adoptive immunotherapy.

Adult↗
PubMed1994

Pathological changes of oxytalan fibers in the human gingiva of chronic periodontitis.

The gingiva samples were obtained from 40 patients with chronic periodontitis after flap operation and 20 cases having healthy gingiva after ectopic wisdom tooth extraction. We investigated the oxytalan fibers by light microscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The results demonstrated that under normal conditions numerous oxytalan fibers were widely and evenly distributed throughout the periodontal tissues. There was marked degeneration of the oxytalan fibers in chronic peridontitis. The predominant features were disintegration, fragmentation or disappearance of the oxytalan fibers under the basement membrane. Around the blood vessels, the oxytalan fibers decreased in density with fragmentation of the fibers and sometimes they disappeared almost completely. These results indicated that degeneration and destruction of the oxytalan fibers were closely correlated with the chronic periodontitis process, leading to reduced function occlusion of teeth.

Adult↗
PubMed1994

[p53 antioncogene abnormal in osteosarcoma].

Immunohistochemical evaluation of 24 osteosarcoma using an anti-p53 protein monoclonal antibody (Moab p53-12) showed strong positive reaction in the nuclei of tumor cells in 14 osteosarcoma (58.3%). Many studies have proved that this overexpression of p53 protein in tumor cells is associated with mutation of the p53 gene. Contrast study with DNA flow cytometry made on osteosarcoma showed that most of the p53 strongly positive tumors have higher DNA Index value than negative or slightly positive ones, though no statistically difference existed between two groups. Southern blot hybridization of p53 gene was also made in osteosarcomas. 5 of 20 cases (20%) had the structural changes of p53 gene. 3 of them were part or whole deletion of the gene. 2 of them had the extra-band, indicating the rearrangement of the gene.

Adolescent↗
PubMed1994

Repair of pectus deformities with sternal support.

During the past 25 years, 252 children underwent repair of pectus deformities. There were 195 male and 57 female patients, of whom 227 had pectus excavatum and 25 had pectus carinatum. Of the 252 patients, 113 underwent repair at between 2 and 5 years of age. Exercise limitation was reported by 51%, and 32% had frequent respiratory infections or asthma. Repair was performed through a transverse incision with subperiosteal resection of the lower four or five costal cartilages, from sternum to costochondral junction bilaterally. A transverse wedge osteotomy was made through the anterior table of the sternum, with fracture but no displacement of the posterior table. For children younger than 5 years (n = 108), the periosteal sheath of the fifth rib from each side was sewn together behind the sternal tip. For older patients (n = 136), a thin steel strut was used for sternal support for 6 months. There were no deaths within the first year. Complications included seroma (16), atelectasis (12), pneumothorax (three), and recurrent chest depression (three). More than 98% of patients had improvements in exercise tolerance, endurance, respiratory symptoms, and cosmetic appearance; these improvements were considered excellent results. Operation at an early age with routine use of substernal support with minimal preoperative and postoperative testing has provided excellent results at a low cost.

Adolescent↗