Search PubMed⌕ Search

Biomedical subjects

R Huang

Publications and source records attributed to R Huang.

At least 73 records · Page 4Linked to original sources
PubMed2000

Effects of rifampin on the glutathione depletion and cytochrome c reduction by acetaminophen reactive metabolites in an in vitro P450 enzyme system.

The present study examined whether rifampin attenuated glutathione (GSH) depletion by acetaminophen reactive metabolites generated in the in vitro P450 enzyme system prepared from mouse liver and the possible mechanism involved in this effect. The results showed that GSH concentration was decreased concentration-dependently by acetaminophen in the in vitro P450 enzyme system. Rifampin significantly attenuated acetaminophen-mediated GSH depletion in a concentration-dependent manner. The concentration-response curve for GSH depletion of acetaminophen was shifted to the right in a parallel fashion in the presence of rifampin at the concentration of 3.2 x 10(-5) M, which appeared to result from the competitive binding of rifampin to acetaminophen metabolites. Cytochrome c was markedly reduced by acetaminophen metabolites in this enzyme system, and GSH concentration-dependently increased the cytochrome c reduction by acetaminophen metabolites. These findings suggested that cytochrome c was reduced by the GSH conjugate of acetaminophen metabolites rather than by acetaminophen-derived superoxide anion (O2*-) and other unbound free radicals. Rifampin was shown to possess an effect similar to that of GSH. It is concluded that the decrease in GSH depletion by rifampin is most likely attributable to the binding of rifampin to the acetaminophen toxic species, and the increase in cytochrome c reduction by rifampin is attributable to the conjugate formed between rifampin and acetaminophen metabolites.

Acetaminophen↗
PubMed2000

[The experimental study on material basis of motor skill plasticity after acute cerebral infarction].

OBJECTIVE: To investigate the structure basis of motor skill plasticity and the recovery mechanism after acute cerebral infarction. METHODS: After MCAO, the motor skill of rats was examined via beam walking test; and the neuron, synapse and the distribution of neurofilament (NF), microtubule associated protein 2 (MAP2), growth associated protein 43 (GAP43) and synaptophysin (SYP) were observed by electron scope and immunohistology staining. RESULTS: All rats had paralysis after MCAO. The motor skill began to recover significantly at the end of 3 weeks, and kept to improve. The number of injured neuron decreased to normal level at week 9 after an increase resulted from MCAO(1st week: 74.6 +/- 8.8/200 field, 9th week: 2.6 +/- 2.5/200 field); the number and structure of synapse regained to normal level gradually, at last outstripped the control group (number of synapse, 1st week: 8.8 +/- 1.7/8,000 field, 9th week: 15.3 +/- 2.4/8,000 field; normal control: 12.3 +/- 2.0/8,000 field); So did SYP, NF and MAP2. The GAP43 increased only at week 1. CONCLUSION: With the reduction of apoptosis cell, the relevant changes in the number, function and structure of synapse form the material basis of motor skill's plasticity together after cerebral infarction. The regeneration of neuron dose not play important role in motor skill recovery.

Acute Disease↗
PubMed2000

[Changes after dynamic observation of ultrastructural cerebral infarction in renovascular hypertensive rats].

OBJECTIVE: To study the ultrastructural damages of brain tissues dynamically after middle cerebral artery obstruction (MCAO). METHODS: A middle cerebral artery obstruction (MCAO) model was reproduced in renal vascular hypertensive rats (RHR). Brain tissues in different locations were collected for eight times in row, from two hours to seven days after establishment of the animal model. RESULTS: The changes occurred in the whole brain after focal cerebral ischemia. The severity of impairment and time of emergence differed with the location sampled. The earliest in the infarcted region with necrosis was considered the major change and completely irreversible damage. The next was seen in marginal regions, mainly with microvascular collapse, formation of microthrombi, and partial necrosis of brain cells and was considered partially reversible damage. The last was in distant and contralateral hemisphere, mainly with reversible swelling of endothelial cells and astrocytes. Changes in the MCAO models reproduced by RHR models were much similar to the clinical pathological changes in cerebral infarction based on the hypertensive cerebrovascular impairment, and it was regarded as a relatively ideal model for studying focal ischemic cerebral impairment. CONCLUSION: Dynamic changes of cerebral ultrastructure in which microvascular impairment plays an important role suggest that clinical therapy cannot only be focused on infarction foci, but also on the whole brain with comprehensively effective measurements.

Animals↗
PubMed2000

A preliminary investigation of Tanakan in the treatment of hypertensive arteriosclerosis and stroke in rats.

OBJECTIVE: To observe the changes in hypertensive cerebral arteriosclerosis and the incidence of stroke in rats following treatment with Tanakan, a preparation of Ginkgo Biloba (GB). METHODS: Using two-kidney, two clip renovascular hypertensive rats (RHRs) as animal models--we investigated changes in these hypertensive arteriosclerosis-associated factors: A I, A II, ALD, ET, SOD and cGMP. Blood levels were observed after oral administration of GB, at both early and late stages of hypertension. RESULTS: The degree of arteriosclerosis was more severe in both RHRs control and the later treated group than in the early treated group, with blood levels of A I, A II, ALD and ET in the former two groups significantly elevated. The degree of arteriosclerosis in the early treated group decreased and the blood levels of A I, A II, ALD and ET in this group decreased nearly to normal levels. The blood levels of SOD and cGMP were also elevated in the early treated group. CONCLUSIONS: These results reveal that it is important to treat hypertension as soon as possible, in order to reduce the occurrence of stroke.

Animals↗
PubMed2000

[High-dose chemotherapy with peripheral-blood stem cells transplantation in patients with advanced gynecological malignant tumors].

OBJECTIVE: To evaluate the clinical effectiveness of high dose chemotherapy(HDC) with peripheral-blood stem cells transplantation(PBSCT) in the patients with advanced malignant tumors. METHODS: Four patients with advanced or refractory ovarian carcinoma and 1 patient with recurrent fallopian tube carcinoma received the HDC with PBSCT after optimal tumor debulking. Of whom 4 patients were with the recurrent or progressive tumors, 1 patient received HDC as primary chemotherapy. The response and toxicity were assessed after treatment. RESULTS: Among 5 patients, four patients are survival. One case died from the recurrence of juvenile granulosa cell tumor. The average survival periods were 21 months. The tumors were all recurrent among the 4 survival patients. The average periods of recurrence after HDC treatment was 9 months. The main toxicity of HDC was severe marrow suppression. The lowest value of the neutrophil count and platelet count was 0.05-0.2 x 10(9)/L and 7 x 10(9)/L-8 x 10(9)/L respectively. The median time to recover a neutrophil count greater than 0.5 x 10(9)/L was 14 days and a platelet count greater than 50 x 10(9)/L was 17 days. None of the patients was complicated with severe complications. CONCLUSIONS: HDC and PBSCT used for ovarian carcinoma was flexibility and security if the patient was selected strictly though its toxicity was severe. Further study among the chemorefactory recurrent patients need to try in the future.

Adult↗
PubMed2000

[Studies on the subgenomic RNAs of hepatitis E virus].

Through labeling HEV RNAs with [32P]-phosphate, two subgenomic RNAs at 6.5 to 7.5 h post-infection, one subgenomic RNA at 8.5 to 10.5 h post-infection and none subgenomic RNAs were detected at 21 post-infection or in purified virus. Hybridization results illustrated that the HEV subgenomic RNAs form a 3' nested set which is situated at the 3' end of genome, but their 5' ends do not share a common leader sequence. UV transcription results showed that the HEV subgenomic RNAs were transcribed independently from its promote. Primer extension analysis suggested that the 5' end of large subgenomic RNA was mapped to the initiative region within RNA polymerase region, and the small subgenomic RNA was mapped to the intergenic region between ORF1 and ORF2.

Cell Line↗
PubMed2000

[Studies on c-myc gene expression and p16 gene inactivation in nasopharyngeal carcinoma].

OBJECTIVE: The alterations of c-myc and p16 genes and their relationship with the development and progression of nasopharyngeal carcinoma were studied. METHODS: Sixty-nine biopsies of nasopharyngeal carcinoma were examined for the homozygous deletion methylation and reduced expression of p16, and the overexpression of myc family oncogenes using multiple PCR, restriction endonuclease coupled PCR, reverse transcriptase PCR and immunohistochemistry. RESULTS: The homozygous deletion and methylation of p16 gene were found in 7 and 11 cases respectively. The total inactivation rate was 26.1% (18/69). The negative expression of p16, as shown by immunohistochemical examination was found in 42 out of 69 cases (60.9%). The overexpression of myc family oncogenes was found in 51 cases (73.9%). CONCLUSION: It suggests that the inactivation of anti-oncogene p16 and the activation of myc family oncogene may play an important role in the development of nasopharyngeal carcinoma.

Adult↗
PubMed2000

Complications in laparoscopic gynecologic surgery.

OBJECTIVE: To investigate retrospectively the complications and associated factors of gynecolgical laparoscopies. METHODS: 1 769 laparoscopic surgeries were carried out from January 1994 to October 1999 at our department. The procedures included 1421 surgeries of ovary and tube, 52 myomectomies and 296 cases of laproscopic-assisted vaginal hysterectomy (LAVH). A total of 312 patients had a history of prior laparotomy (17.6%). RESULTS: Complications occured in 34 cases, the overall complication rate was 1.92%. Unintended laparotomies occured in 6 cases (0.34%). 12 complications were associated with insertion of Veresse needle or trocar and creation of pneumoperitoneum, including 5 severe emphysema and 7 vascular injuries, this figure represents 35.3% of all complications of this series. Five intraoperative complications (14.7%) occured during the laparoscopic surgery (3 severe bleedings, one bladder injury and one skin burn of leg caused by damaged electrode plate), laparotomy was required in four of these cases. Seventeen complications occured during postoperative stage: 2 intraperitoneal hemorrhages needing laparotomy, 2 bowel injuries, 4 nerve paresis and 9 febrile morbidities. CONCLUSIONS: Operative gynecologic laparoscopy is associated with acceptable morbidity rate, but can not be overlooked. Complication rate seems to be higher in advanced procedures such as LAVH.

Female↗
PubMed1999

Activation of p90RSK and cAMP response element binding protein in stimulated neutrophils: novel effects of the pyridinyl imidazole SB 203580 on activation of the extracellular signal-regulated kinase cascade.

Neutrophils stimulated with the chemoattractant FMLP or the phorbol ester PMA are known to exhibit activation of a 90-kDa renaturable protein kinase. Activation of this kinase was maximal at approximately 1-3 min after cell stimulation and the time course for activation was similar to that of the extracellular-regulated kinases (ERKs) and p38-mitogen activated protein kinase (p38MAPK). Compounds that block activation of ERK-1/2 (PD 98059) or that inhibit the activity of p38MAPK (SB 203580) blocked activation of this 90-kDa kinase. SB 203580 is a highly selective inhibitor of p38MAPK in vitro and is under intense study as a lead compound for developing novel anti-inflammatory agents. However, we demonstrate that SB 203580 at concentrations >/=10 microM can also inhibit activation of ERK-1/2 in neutrophils. An Ab to the protein kinase p90RSK2 (also referred to as MAPKAP-K1b, or p90rsk) immunoprecipitated the active 90-kDa kinase from lysates of stimulated neutrophils. No activity was observed for this enzyme in immunoprecipitates obtained from unstimulated cells, and the amounts of activity were markedly reduced if the cells were treated with PD 98059 or SB 203580 before stimulation. Neutrophils stimulated with FMLP exhibited phosphorylation of the cAMP response element binding protein (CREB), and this reaction was inhibited by SB 203580 and PD 98059. These data establish that the renaturable 90-kDa protein kinase is p90RSK2 and that CREB may be a substrate for this enzyme in these cells. Novel effects of compound SB 203580 on stimulated neutrophils are also described.

Animals↗
PubMed1999

Diagnosis of disorders of platelet function by flow cytometry.

The platelet membrane glycoprotein (GP) IIb/IIIa, GPIX were detected by immunogold assay and flow cytometry, respectively, in two cases of Glannzmann's thrombasthenia (GT). The immunogold assay showed that the GP IIb/IIIa gold granules in GT were decreased obviously, compared with that in normal controls. Flow cytometry results showed that GP IIb/IIIa in two cases of GT was 0.1% and 0.5% of normal control, respectively. While GPIX showed no difference between the GT and normal control. The patients' father showed no bleeding symptoms, whose GP IIb/IIIa accounted for 36.99% of normal control. The experiment results suggested that flow cytometry is a quick, simple and sensitive method for the diagnosis of GP disorders.

Adult↗
PubMed1999

Origin and development of the avian tongue muscles.

The musculature of the vertebrate tongue is composed of cells recruited from the somites. In this paper we have investigated the migration and organisation of the muscle cells that give rise to the tongue muscle during chick embryogenesis. At the molecular level, our data suggests that a population of Tbx-3 expressing cells migrate away from the occipital somites prior to the migration of muscle precursors that express Pax-3. Both populations take the same pathway and form the hypoglossal cord. The first signs of muscle cell differentiation were not detected until cells had migrated some distance from the somites. We have determined the contribution of single somites to the musculature of the tongue and show in contrast to previous data that somites 2-6 take part in the formation of all glossal and infrahyoid muscles to the same extent but do not contribute to suprahyoid muscle. This is particularly interesting since glossal and infrahyoid muscle differ from the suprahyoid muscles not only in their morphology, but also in their developmental origin. Furthermore we show that myocytes cross the midline and contribute to the contralateral glossal and infrahyoid muscles. This is supported from our molecular data, which showed that the migratory precursor population was maintained primarily at the rostral tip of the developing hypoglossal cord.

Animals↗
PubMed1999

Anesthetic methods for reduction of acute shoulder dislocations: a prospective randomized study comparing intraarticular lidocaine with intravenous analgesia and sedation.

A prospective, randomized, nonblinded clinical trial was undertaken to evaluate whether local intraarticular lidocaine injection (IAL) is equally effective in facilitating reduction of acute anterior shoulder dislocations (AASD) as intravenous analgesia/sedation (IVAS). The setting was an urban, Level 1, trauma center. Patients enrolled presented to the emergency department (ED) with radiographically confirmed AASD and were randomized either to the IVAS group or the IAL group. Ease of reduction and pain associated with reduction were measured subjectively using a 10-point scale. There were 49 patients entered into the study, 20 in the IVAS group and 29 in the IAL group. There was no statistically significant difference between mean +/- SD pain scores of 3.32+/-2.39 in the IVAS group and 4.90+/-2.34 in the IAL group (P = .18), or mean +/- SD ease of reduction scores of 3.32+/-2.36 in the IVAS group and 4.45+/-2.46 in the IAL group (P = .12). Although IVAS tended to have a higher success rate (20 of 20) than IAL (25 of 29) in this study, Kaplan-Meier estimates for delayed time-events curves applying the log-rank test showed that this difference was not statistically significant overall (P = .16). However, with reduction rate evaluated as a function of time delay in seeking treatment, patients presenting 5.5 hours after dislocation were more likely to fail treatment with IAL (P = .00001). Additionally, half of the patients in the IAL group who had experience with IVAS did not favor IAL. Emergency physicians should be aware of IAL as an alternative technique that may be considered in patients when there are reasons to avoid systemic analgesia or sedation.

Adult↗
PubMed1999

Heterogeneity of HLA-DR2 haplotypes in Caucasoid Americans, African Americans, Chinese Americans, Native Americans and Xiamen Chinese.

HLA-DR, -DQ specificities were determined by PCR amplification with SSOP in 4560 individuals: Caucasoid Americans (CA), African Americans (AA), Chinese Americans (ChA), Native Americans (NA) and Xiamen Chinese (XC). DR2 subtypes were compared amongst the five ethnic populations. The DRB1*1501-DRB5*0101 haplotype was found to be the most frequent in all populations except African Americans, in which DRB1*1503-DRB5*0101 was the predominant haplotype, accounting for 65% of DR2 subtypes. In contrast to Caucasoid Americans, the DRB1*1602 is strongly associated with the DRB5*0101 allele in Chinese populations. The presence of DRB5*0203 and DRB1*1602-DRB5*0101 haplotypes in Chinese populations, especially in Xiamen Chinese, suggests that various DR2 haplotypes may be generated via multiple gene conversion events together with point mutations and reciprocal recombination. The strong DR and DQ associations are found in DRB1*1501/DQB1*0602 (66.22%) for CA, DRB1*1503/DQB1*0602 (56.58%) for AA, DRB1*1501/DQB1*0602 (30.20%) and DRB1*1602/DQB1*0502 (15.76%) for ChA, DRB1* 1501/DQB1*0602 (41.55%) and DRB1*1602/DQB1*0301 (40.25%) for NA, and DRB1*1501/DQB1*0602 (30.26%) and DRB1*1602/DQB1*0502 (25.81%) for XC.

Alleles↗
PubMed1999

Cell culture of sporadic hepatitis E virus in China.

The isolation and identification of the 87A strain of epidemic hepatitis E virus (HEV) by means of cell culturing have been described previously. This paper reports the successful isolation of a sporadic HEV strain (G93-2) in human lung carcinoma cell (A549) cultures. The etiology, molecular and biological properties, and serological relationship of this new strain to other, epidemic HEV strains are described. The propagation of both sporadic and epidemic HEV strains in a cell culture system will facilitate vaccine research.

Acids↗
PubMed1999

[Gene analysis of acute sporadic HEV in the southern areas of China].

OBJECTIVE: To investigate the existing different gene sequences of hepatitis E virus (HEV) in the southern areas of China. METHODS: Eight acute-phase sera of sporadic patients with hepatitis E in Xiamen were tested by reverse transcription--polymerase chain reaction(RT-PCR). Two cases of them were positive. The fifth passage culture of Guangzhou G93-2 strain of HEV was also detected by RT-PCR. The positive RT-PCR products underwent cloning and nucleotide sequencing. RESULTS: The homology of nucleotide and the amino acid between Xiamen X-S1 and Guangzhou G93-2 strain are 99.2% and 97.5%. The homology of nucleotide and the amino acid sequences of Xiamen strain and Guangzhou strain are 79.9% and 86.3% compared with the Burmese strain (Bur-121) and our country Xinjiang strain (87A), and are 77.4% and 86.3% against Mexican strain. CONCLUSION: The results suggest that there is a different genotype of HEV in the southern areas of China.

Acute Disease↗
PubMed1999

[Diagnosis and treatment of endodermal sinus tumor of the vagina].

OBJECTIVES: To describe the clinical characteristics and the role of chemotherapy in endodermal sinus tumor of the vagina. METHOD: Two patients with endodermal sinus tumor of the vagina were presented focusing on the clinical manifestations and outcome of the chemotherapy. RESULTS: Patient's age was quite young, 2 and 3 years old respectively. Vaginal bleeding and a polypoid and fragile tumor of the vagina were main clinical features. Elevated serum alpha-FP was found before chemotherapy and dropped dramatically to normal if the tumor was sensitive to chemotherapy. Diagnosis was made by pathology and alpha-FP immunohistochemical staining. Both two patient was well responded to cisplatin vincristine bleomycin (PVB) and cisplatin etoposide bleomycin (PEB) chemotherapy. Clinical and pathological complete remission was obtained after 2-3 courses of chemotherapy without radical surgery and radiotherapy. CONCLUSIONS: Endodermal sinus tumor of vagina in infant was very sensitive to the chemotherapy. Serum alpha-FP was very useful in diagnosis and monitoring of the disease.

Antineoplastic Combined Chemotherapy Protocols↗