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Biomedical subjects

H Guo

Publications and source records attributed to H Guo.

At least 199 records · Page 11Linked to original sources
PubMed1997

[Preliminary study on the absorption, distribution and excretion of doxophylline in rats].

Doxophylline, a new antibronchospastic drug, being more active and less toxic than aminophyline, was detected by high-performance thin layer chromatography. The pharmacokinetics of doxophylline have been characterized in rats, whose serum concentration were monitored after 100, 200, 400 mg.kg-1 oral dose. The drug was found to conform to a one-compartment model and can be bio-transformed quickly in rats. The Cmax, AUC and CL/F appeared to be dose-dependent. T1/2 (Ke) was 1.17 +/- 0.13 h after the 100 mg.kg-1 dose, 2.54 +/- 0.60 h after the 200 mg.kg-1 dose and 3.75 +/- 0.92 h after the 400 mg.kg-1 dose. The doxophylline concentration in tissues decreased rapidly. Total excretion of the drug in urine, bile and faeces was 5.2 per cent of the dose. Plasma protein binding was about 25 percent.

Absorption↗
PubMed1997

Diagnosis and treatment of stage-III peripheral squamous cell carcinoma of right upper lung.

During a 12-year period, 44 patients were surgically treated for stage-III peripheral squamous cell carcinoma of the right upper lobe. The mean time from the discovery of the shadow in the right upper lobe to the confirmation of the diagnosis was 2 months. All patients underwent the resection of the right upper lobe with the dissection of the right mediastinal lymph nodes, among them, 4 patients had sleeve lobectomy of the right upper lobe. P-TNM staging: 23 cases were in stage-IIIa, 21 cases in stage-IIIb. The frequency of the postoperative complications was 20.4% (9/44 cases). The 1-year survival rate of all patients was 61% (27/44 cases). None of stage-IIIb patients lived longer than 3 years. The postoperative 3- and 5-year survival rates of stage-IIIa cases were 65.2% (15/23 cases) and 21.7% (5/23 cases) respectively. In this article, the patients' clinical features, the causes of delayed-diagnosis, the operative and postoperative management were discussed. We suggest that the stage-IIIa patients should be given surgical treatment, whereas, for the patients of stage-IIIb, palliative operation was given just for the purpose of reliving the symptoms.

Aged↗
PubMed1997

[Application of computerized image analyzing system in morphometric study of vascular smooth muscle cells].

The authors used image analyser to measure several morphometric parameters of cultured aorta vascular smooth muscle cell (VSMC) and assess the relationships between these morphometric parameters and 3H-TdR incorporations. On this basis, the authors also explored the effect of Ligustrazine, a traditional Chinese medicine, on VSMC morphology in order to evaluate the role of computerized image analysing system in the study of VSMC proliferation. The results showed that (1) there were significant correlations between VSMC cellular area, nuclear area and 3H-TdR incorporations in control group; (2) Ligustrazine significantly decreased VSMC cellular area, nuclear area and nuclear perimeter, and a significant correlation was also noted between cellular area and 3H-TdR incorporation in Ligustrazine group. These suggest that computerized image analysing system is a rapid, accurate and reliable method to study the morphology and proliferation of VSMC.

Animals↗
PubMed1997

[Detection of flaviviruses by reverse-transcription polymerase chain reaction with universal primer set].

For the purpose of early and rapid diagnosis of flavivirus infection, the universal primer set was selected on the NS1 gene. Another five different internal primers were selected on the NS1 genes of DEN1, 2, 3, 4 and JEV. With the universal primer set designed, the NS1 fragment about the size of 413 bp and with the five internal primers, the NS1 fragments about the sizes of 262 bp (DEN1), 189 bp (DEN2), 392 bp (DEN3), 97 bp (DEN4) and 323 bp (JEV) were amplified respectively. The reverse transcription-polymerase chain reaction (RT-PCR) was used to amplify gene fragments of flaviviruses. cDNA of DEN1, 2, 3, 4 and JEV were successfully amplified with universal primer set and internal primers. Sera from 78 patients with dengue fever were assayed by nested PCR, DEN1 was detected from 18 of the 40 patients' sera and DEN2 was detected from 48 patients' sera. Sera from 42 patients with Japanese encephalitis were also assayed by nested PCR, JEV was detected from 35 of the 42 patients' sera. By nested PCR, we completed identification of flaviviruses within 2 days. The results showed that this method has the potential value in rapid clinical diagnosis of flavivirus infection.

DNA Primers↗
PubMed1997

Auditory P300, CT scans and cognitive state in Binswanger's disease.

The P300 component of evoked potential can reflect cognitive state in dementia patients. The purpose of this study was to investigate the value of P300 as an indicator of cognition in Binswanger's disease (BD) and to explore the possible causes of dementia in BD patients. P300 was measured at Cz site in 21 patients with BD and 21 controls matched with age, sex, handedness, and education. This measurement included P300 latency and amplitude. All patients were also given WAIS-RC test and scanned with computerized tomography (CT), and were treated with hyperbaric oxygenation (HBO). The relationships among P300, CT and WAIS-RC score were studied. BD patients had significantly prolonged P300 latency and a tendency of low amplitude P300, but the amplitude difference was not significant compared with controls. P300 latency was found to be negatively correlated with WARS-RC scale, and positively correlated with the change of white matter low attenuation (WMLA). WMLA was also correlated with WAIS-RC score. Treatment with HBO reduced P300 latency and had effect on the cognitive part of P300 but had no effect on CT changes. The significant association between neurophysiological and neuropsychological measurement suggests that P300 measurement reflects a disrupted aspect of cognitive function in BD patients, and it may be a useful means to assess the degree of subcortical cognitive deterioration and the effect of therapy. White matter lesion in BD is concerned to the occurrence of dementia by disturbing axonal conduction.

Aged↗
PubMed1997

Establishment of doxorubicin-resistant human bladder cancer cell line (BUI-87/ADMR) and its mechanism of multidrug resistance.

OBJECTIVE: To establish a doxorubicin-resistant human bladder cancer cell line, BIU-87/ADMR, and to study its biological characteristics and mechanism of drug resistance. METHODS: A human bladder cancer cell line resistant to doxorubicin, BIU-87/ADMR, has been established in vitro by exposing BIU-87 parent cells to progressively increasing concentrations of the drug over a period of 8 months. The cell line has been characterized in terms of growth kinetics, morphology, cross-resistance to other anticancerous agents, pharmacokinetics of daunorubicin and expression of P-glycoprotein (P-gp) which is closely related to the MDR phenotype. RESULTS: The BIU-87/ADMR cell line was 6.3 times more resistant to doxorubicin than the parent BIU-87. It exhibited cross-resistance to doxorubicin derivatives (epirubicin, daunorubicin), vincristine and etoposide, but not to cisplatin and mitomycin C. Compared to the parent cells, the resistant cells have a slower growth rate and lower confluent density. Unlike the parent BIU-87, about 75% of the BIU-87/ADMR cells showed a positive reaction with monoclonal antibody against P-gp, JSB-1. Intracellular drug accumulation studies with fluorescence spectrometry indicated that the resistance exhibited by the BIU-87/ ADMR line was mainly caused by an increased active efflux. CONCLUSIONS: The results suggest that MDR is an important phenomenon in bladder cancer and that more than one pathway of MDR may be present in human bladder cancer cell lines. BIU-87/ADMR may be a useful model for the development of new chemotherapeutic strategies in overcoming drug-resistance in the treatment of bladder cancer.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Detection of chlamydia trachomatis by polymerase chain reaction assay in nonbacterial prostatitis.

OBJECTIVE: To evaluate the sensitivity and specificity of polymerase chain reaction (PCR) technique in comparison with diethylaminoethyl-dextran (DEAE-dextran)-treated HeLa cell culture method for detection of chlamydia trachomatis in nonbacterial prostatitis. METHODS: Thirty patients had symptoms of prostatitis for at least three months. None of them had evidence of urethritis on urethral Gram stain or recurrent bacteria. Routine localization of bacteria was negative. White blood cell count in expressed prostatic secretion (EPS) was more than 10 per high-power field (10/HPF). None of these patients had received antibiotics during the six weeks before the study, although all had received multiple courses of antibiotics for treatment of prostatitis syndrome. The EPS specimens from these patients were placed in 0.5-ml Eppendorf tubes and stored at -70 degrees C until they were processed for PCR and DEAE-dextran-treated HeLa cell culture. RESULTS: Six specimens were positive for C. trachomatis by both PCR and culture, and 21 were negative by both tests. There were three specimens with discrepant results, including two that were positive by PCR and negative by culture, and one that was positive by culture and negative by PCR. Comparing PCR technique with culture method, the sensitivity, specificity, positive predictive value and negative predictive value of the former were 85.7%, 91.3%, 75.0% and 95.5% respectively. CONCLUSIONS: PCR analysis of EPS is a highly sensitive and specific noninvasive technique for detection of chlamydia trachomatis. It provides a unique opportunity for early identification of or rapid screening for chlamydia trachomatis infection in patients with nonbacterial prostatitis. The reliability of PCR assay offers clinicians a clear indication for the initiation of treatment of chlamydia trachomatis infection.

Chlamydia Infections↗
PubMed1997

Tapeworm infection resulting from pork eaten at a wedding banquet.

Forty-five people who had attended a wedding banquet were examined by means of both Avidin-Biotin Peroxidase Complex-ELISA (ABC-ELISA) and Kato stool thick smear technic. The results revealed that the positive rates with ABC-ELISA were 15.56% (7/45) and Kato Katz 0.62% (1/161). There was a significant difference between the two positive rates (p < 0.005). Six people at the wedding had taeniasis and 4 of them also had cysticercosis. Local people have no habit of eating uncooked pork, but at this banquet the meat from an infected cysticerci pig was used for preparing dishes for the wedding feast and the cold dishes were contaminated by the bladder worms as the result of using the same chopping block.

Animals↗
PubMed1997

A study on the culture medium antigens of Cystcercus cellulosae for detecting antibodies of cysticercosis by means of ABC-ELISA.

Two antigens of Cysticercus cellulosae, cystic fluid antigen (CFA) and the culture medium antigen (CMA), were used in Avidin-Biotin Peroxdase Complex-ELISA (ABC-ELISA) to detect IgG antibodies in 45 cases of cysticercosis treated with praziquantel. The results revealed the total positive rates as 51.11% with CMA and 82.22% with CFA. The positive rates in the cases treated within 2 courses of treatment were 79.17% for CMA and 87.50% for CFA, and only 19.05% for CMA and 71.43% for CFA in the cases treated for more then 3 courses. The fact that the positive rates decreased as the courses of treatment increased showed that the sensitivity of CMA might be related to the vital conditions of the worms in the body, whether alive or dead. It is, therefore, recommended that CMA has the potential to be employed in ABC-ELISA both as an indicator for diagnosing cysticercosis and as a reference for the evaluation of the treatment.

Animals↗
PubMed1997

Observations on the effects of cysticercosis immune sera on cysticercosis by scanning electronmicroscopy.

Two antigens of Taenia solium cysticercus, cystic fluid antigen (CFA) and the culture medium antigen (CMA), were used respectively to immunize rabbits in order to obtain immunosera. The CMA immunoserum added to culture medium with cysticerci limited the activities of the bladder worms. By using the scanning electronmicroscope, we could observe particulate deposits on the surface of the scolices, suckers and necks of the worms. The CFA immunoserum group showed similar changes but the deposit was less than that on the worms in the former group and appeared mainly on the cystic wall. After adding complement to the two groups mentioned above, we found that the microcilia on the surface of the worms were swollen and were seriously damaged. The worms treated with praziquantel were damaged over large area of their surfaces and were affected deep into their tissues. The damaged parts of the worms were quite different between the two groups. CMA is secreted by the living worms and therefore the serum antibodies are more effective than CFA in anti-parasite activity.

Animals↗
PubMed1996

Major susceptibility locus for prostate cancer on chromosome 1 suggested by a genome-wide search.

Despite its high prevalence, very little is known regarding genetic predisposition to prostate cancer. A genome-wide scan performed in 66 high-risk prostate cancer families has provided evidence of linkage to the long arm of chromosome 1 (1q24-25). Analysis of an additional set of 25 North American and Swedish families with markers in this region resulted in significant evidence of linkage in the combined set of 91 families. The data provide strong evidence of a major prostate cancer susceptibility locus on chromosome 1.

Adult↗
PubMed1996

Effect of the crystallizing agent 2-methyl-2,4-pentanediol on the structure of adenine tract DNA in solution.

The hydroxyl radical cleavage pattern of bent DNA containing phased adenine tracts has a sinusoidal pattern. Changes in the cleavage pattern of the sequence A5N5 in the presence of 2-methyl-2,4-pentanediol (MPD) demonstrate that MPD has an effect on the structure of a bent A-tract region of DNA. The effect of MPD on DNA structure appears to be limited to bent A-tract regions, as we find no significant changes in the cleavage pattern of flanking regions, mixed-sequence DNA, or the unbent A-tract sequence T4A4N2.

Crystallography↗
PubMed1996

Postnatal methadone exposure doe not prevent prenatal methadone-induced changes in striatal cholinergic neurons.

On postnatal day 4, rats exposed to methadone prenatally but fostered to control dams, as well as those fostered to dams treated with methadone, exhibited significant reductions in striatal acetylcholine (ACh) content. This suggests that neonatal withdrawal from methadone is not responsible for the effects of prenatal exposure on cholinergic development in the early perinatal period. The effects of perinatal exposure to methadone on serotonin (5HT) and dopamine (DA) metabolism do not appear to be strictly related to changes in ACh content. Although prenatal exposure reduces 5-hydroxyindole acetic acid (5HIAA) content, changes in 5HT content prevent significant changes in the ratio 5HIAA/5HT. Pups exposed to methadone only prenatally (withdrawal group) exhibited a decreased DOPAC/DA ratio, whereas pups in the treatment group exposed to methadone both pre- and postnatally exhibited an increased DOPAC/DA ratio.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1996

Regulation of transcription in mammalian cells by yeast Leu3p and externally supplied inducer.

The Leu3 protein of yeast is a dual-function regulator, stimulating transcription when the inducer alpha-isopropylmalate (alpha-IPM) is present and suppressing transcription when the inducer is absent. Here we show that Leu3p retains both its positive and negative regulatory properties when expressed in mammalian cells or when added to a mammalian nuclear extract. Alpha-IPM stimulates reporter gene expression 15-20-fold, both in vivo and in vitro. The concentration of alpha-IPM required for half-maximal stimulation in vitro is 2.5 x 10(-4) M. No yeast-specific factors other than Leu3p itself are required for up- or down-regulation. Since alpha-IPM is not metabolized in mammalian cells, the Leu3p-alpha-IPM system might be useful in gene therapy and other studies as a highly specific, externally controlled on/off switch of gene expression.

Animals↗