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Biomedical subjects

Y Lou

Publications and source records attributed to Y Lou.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Inhibitory effects of recombinant human neurotrophin-4/5 protein on neurotoxicity caused by arsenic trioxide].

OBJECTIVE: To study preliminarily the inhibitory effects of recombinant human neurotrophin (hNT)-4/5 protein on neurotoxicity caused by arsenic trioxide (As(2)O(3)). METHODS: Nerve cells of the chicken embryonic forebrain and PC12 cells were co-cultured with recombinant hNT-4/5 protein and As(2)O(3) (0 - 16 micromol/L) for 24 and 48 hours, respectively, to observe the survival of nerve cells and the outgrowth of PC12 cells, with clone expression and recombination techniques. RESULTS: There was significant difference in survival rate of nerve cells between the experimental and control groups (P < 0.01) after co-culture for 48 hours, and survival rate and number of neuron outgrowth increased with the concentration of hNT-4/5 protein. CONCLUSION: Recombinant hNT-4/5 protein could inhibit neurotoxicity caused by As(2)O(3), which provided a basis to find an anti-toxic factor in the environment by genetic engineering.

Animals↗
PubMed1998

Insulin receptor exon 11+/- isoform mRNA in spontaneously hypertensive and adrenocorticotropin-hypertensive rats.

OBJECTIVE: To test the hypothesis that insulin resistance of the spontaneously hypertensive rat (SHR) and adrenocorticotropin-hypertensive rat is related to a difference in the proportion of the functionally different, alternatively spliced exon 11 isoforms of the insulin receptor. DESIGN: We determined the proportions of mRNA for the exon 11+ and exon 11- isoforms in various tissues of SHR and Wistar-Kyoto rats aged 3, 6, 9 and 12 weeks, which span the pre-hypertensive phase through to established hypertension, as well as in Sprague-Dawley rats with adrenocorticotropin-induced hypertension and Sprague-Dawley controls. METHODS: Detection of mRNA involved a reverse-transcriptase polymerase chain reaction technique specific for each isoform and quantification was by slot and dot blot hybridization. RESULTS: Mean proportions of exon 11+ mRNA in SHR, Wistar-Kyoto rats, adrenocorticotropin-hypertensive rats and Sprague-Dawley control rats at each age were 95% for liver, 82% for adipose tissue, 77% for kidney, 66% for adrenal, 53% for heart, 26% for cerebral cortex, 23% for hypothalamus, and 3% for skeletal muscle. There was also no difference in concentration of total insulin receptor mRNA. CONCLUSIONS: The absence of any difference in proportions of insulin receptor mRNA isoforms argues against the hypothesis that an alteration of differential splicing plays a role in the models of hypertension studied.

Adrenocorticotropic Hormone↗
PubMed1998

[A study on diagnosis of ocular adnexal lymphoid hyperplasia by polymerase chain reaction amplified IgH CDR-III sequence].

OBJECTIVE: To study the diagnosis and classification of ocular adnexal lymphoid hyperplasia and investigate its cell origin by using some molecular biological techniques. METHODS: 29 cases (31 eyes) of ocular adnexal lymphoid hyperplasia were examined for immunoglobulin heavy-chain (IgH) gene rearrangements by means of polymerase chain reaction (PCR) to amplify the complementarity determining region III (CDR-III) with formalin-fixed and paraffin-embedded tissue combining with histopathologic examination and immunophenotypic analysis. RESULTS: 17 eyes of malignant lymphoma and 5 eyes of reactive lymphoid hyperplasia demonstrated clear single band of the rearranged gene for the IgH chain between 100 bp. to 120 bp. The bilateral ocular adnexal lymphoma occurring simultaneously in 4 eyes (two individuals) exhibited identical band. 1 eye of malignant lymphoma, 8 eyes of atypical lymphoid hyperplasias and 6 eyes of reactive lymphoid hyperplasia showed no band or a smear band. CONCLUSIONS: The results show that this method can determine the clonality of the lymphoid hyperplasias. It may be as well in the examination of small monoclonal B cell populations for which immunophenotypical analysis is difficult. The method is an objective, accurate and useful approach for the diagnosis of ocular adnexal lymphoid hyperplasias.

Complementarity Determining Regions↗
PubMed1998

[Effects of different thyroid status on the pharmacokinetics of diazepam].

Experimental models of hypothyroidism and hyperthyroidism in Sprague-Dawley rats were established in this study. Diazepam was given to rats at a single oral dose of 30-40 mg.kg-1 and the plasma concentration of diazepam was detected by HPLC. The results showed that the plasma concentration of diazepam was significantly higher in hypothyroid rats than that in controls (P < 0.05). The Cmax, AUC and T1/2 (Ka) were increased. The Vd was decreased and the elimination was slowed. Mild hyperthyroidism showed nearly no effect on the plasma concentration, Cmax and AUC of diazepam in the rats. But when the rats became more heavily hyperthyroid, the plasma concentration, Cmax and AUC of diazepam were increased gradually. The absorption of diazepam was changed slightly in mild and moderate hyperthyroid rats, the Vd was decreased and the elimination was accelerated. In heavily hyperthyroid rats, however, the absorption of diazepam was obviously accelerated. The Vd was decreased and the elimination was slowed. Therefore, we conclude that different thyroid status may have different effects on the pharmacokinetics of diazepam.

Animals↗
PubMed1998

[Pharmacokinetic profile of naftopidil in rats].

Naftopidil(Naf), a novel antihypertensive drug, was determined by HPLC-UV method. The plasma concentration and pharmacokinetics of naftopidil have been investigated in rats after single oral doses of 10, 20 and 30 mg.kg-1. The drug was found to conform to a two-compartment model. Tp was in the range of 0.42 h to 0.90 h. T1/2 beta was 7.08 h after the 10 mg.kg-1 dose, 4.78 h after the 20 mg.kg-1 dose and 5.83 h after the 30 mg.kg-1 dose. The Cmax, AUC and CL/F appeared to be dose dependent at the doses not higher than 20 mg.kg-1. Naf was found in many tissues after a single oral dose of 20 mg.kg-1. The top level tissues were intestine, liver and lung at 15 minutes after administration, while the utero-ovarian tissue was the highest at 6 h. Naf can be extensively metabolized since the total excretion of the parent compound in urine and faeces was less than 1% of the dose. From 82% to 97% of Naf in plasma was shown to be bound to protein.

Animals↗
PubMed1998

[Determination of adenosine in Rehmannia glutinosa Libosch. by HPLC].

OBJECTIVE: To establish a method to determine the contents of asenosine in different species of Rehmannia glutinosa. METHOD: The contents were determined by HPLC, with a column of KYWG-C18 as stationary phase, 6% ace tonitrile as mobile phase and detecting wavelength at 260 nm. RESULT: Adenosine has a good linearity in the range of 0.002 mg/ml-0.01 mg/ml, Y = 1.7742 x 10(-4) + 8.9021 x 10(-7) X, r = 0.9995. The average recovery is 94.1% and RSD = 1.86% (n = 5). CONCLUSION: The method is fast, reliable and simple.

Adenosine↗
PubMed1997

Effect of hypoxia on the proliferation of retinal microvessel endothelial cells in culture.

BACKGROUND: To determine if hypoxia stimulates the proliferation of retinal microvessel endothelial cells in culture. METHODS: Bovine retinal microvessel endothelial cells were cultured in normoxic (95% air, 5% CO2) and hypoxic (2% O2, 5% CO2, 93% N2) conditions. Endothelial cells were identified by acetylated LDL and Factor VIII-related antigen immunocytochemical staining. Cells from passages three to eight were used in these experiments. Proliferation assays included cell counts by hemocytometer and autoradiographic analysis of incorporated 3H-thymidine (3H-TdR). RESULTS: At day 4, cell counts of endothelial cells in hypoxia showed a 133% increase over those grown in normoxic conditions (N = 25, P < 0.01). Cell counts per day for 5 days were 121-181% greater in hypoxia. Autoradiography of endothelial cells exposed to 3H-TdR and counted every 12 hours for 60 hours exhibited labeling indices 112-118% higher in hypoxic conditions (P < 0.0001). Endothelial cells cultured under hypoxic conditions were smaller and spindle-shaped, whereas those grown under normoxic conditions were larger and more polygonal. CONCLUSIONS: Hypoxia increases DNA synthesis and stimulates proliferation of retinal microvessel endothelial cells in vitro and induces alterations in morphology. These results may be relevant to microvessel angiogenesis, which occurs in vivo under ischemic conditions.

Animals↗
PubMed1997

Adaptation to sublethal environmental stresses protects Listeria monocytogenes against lethal preservation factors.

A sublethal dose of ethanol (5%, vol/vol), acid (HCl, pH 4.5 to 5.0), H2O2 (500 ppm), or NaCl (7%, wt/vol) was added to a Listeria monocytogenes culture at the exponential phase, and the cells were allowed to grow for 1 h. Exponential-phase cells also were heat shocked at 45 degrees C for 1 h. The stress-adapted cells were then subjected to the following factors at the indicated lethal levels--NaCl (25%, wt/vol), ethanol (17.5%, vol/vol), hydrogen peroxide (0.1%, wt/vol), acid (pH 3.5), and starvation on 0.1 M phosphate buffer at pH 7.0 (up to 300 h). Viable counts of the pathogen, after the treatment, were determined on Trypticase soy agar-yeast extract, and survivor plots were constructed. The area (h.log10 CFU/ml) between the control and treatment curves was calculated to represent the protective effect resulting from adaptation to the sublethal stress factor. Adaptation to pH 4.5 to 5.0 or 5% ethanol significantly (P < 0.05) increased the resistance of L. monocytogenes to lethal doses of acid, ethanol, and H2O2. Adaptation to ethanol significantly (P < 0.05) increased the resistance to 25% NaCl. When L. monocytogenes was adapted to 500 ppm of H2O2, 7% NaCl, or heat, resistance of the pathogen to 1% hydrogen peroxide increased significantly (P < 0.05). Heat shock significantly (P < 0.05) increased the resistance to ethanol and NaCl. Therefore, the occurrence of stress protection after adaptation of L. monocytogenes to environmental stresses depends on the type of stress encountered and the lethal factor applied. This "stress hardening" should be considered when current food processing technologies are modified or new ones are developed.

Adaptation, Physiological↗
PubMed1997

[A study on the loss of heterozygosity at 17p13.3 and abnormal expression of p53 protein in gastric carcinoma].

OBJECTIVE: To evaluate the role of 17p13.3 loss and abnormal expression of p53 in the development and progress of gastric carcinoma. METHODS: The loss of heterozygosity (LOH) at 17p13.3 and abnormal expression of p53 gene were examined with PCR-RFLP and immunohistochemical methods in 51 surgical specimens of gastric carcinoma. RESULTS: LOH at 17p13.3 was detected in 16/31 cases (51.6%) and positive staining for p53 protein was found in 19/51 cases (37.3%). No significant correlation was found between LOH at 17p13.3 and abnormal expression of p53 or between these two events in any clinicopathological parameters. LOH was found in one cases of early gastric cancer. CONCLUSIONS: These results suggest that LOH at 17p and abnormal expression of p53 protein are frequently found in gastric carcinoma and may play an important role in the carcinogenesis and progress of both intestinal and gastric types of gastric cancer.

Adenocarcinoma↗
PubMed1996

Colonization with group B streptococci in pregnancy and adverse outcome. VIP Study Group.

OBJECTIVE: Our purpose was to study the association of cervicovaginal colonization with group B streptococci with pregnancy and neonatal outcome. STUDY DESIGN: A prospective study was conducted at seven medical centers between 1984 and 1989. Genital tract cultures were obtained at 23 to 26 weeks' gestation and at delivery. Prematurity and neonatal sepsis rates were compared between group B streptococci positive and negative women. RESULTS: Group B streptococci was recovered from 2877 (21%) of 13,646 women at enrollment. Heavy colonization was associated with a significant risk of delivering a preterm infant who had a low birth weight (odds ratio = 1.5, 95% confidence interval 1.1 to 1.9). Heavily colonized women given antibiotics effective against group B streptococci had little increased risk of a preterm, low-birth-weight birth. Women with light colonization were at the same risk of adverse outcome as the uncolonized women. Neonatal group B streptococci sepsis occurred in 2.6 of 1000 live births in women with and 1.6 of 1000 live births in women without group B streptococci at 23 to 26 weeks' gestation (p = 0.11). However, sepsis occurred in 16 of 1000 live births to women with and 0.4 of 1000 live births to women without group B streptococci at delivery (p < 0.001). CONCLUSIONS: Heavy group B streptococci colonization of 23 to 26 weeks' gestation was associated with an increased risk of delivering a preterm, low-birth-weight infant. Cervicovaginal colonization with group B streptococci at 23 to 26 weeks' gestation was not a reliable predictor of neonatal group B streptococci sepsis. Colonization at delivery was associated with sepsis.

Female↗
PubMed1996

Overall and cause-specific mortality in a cohort of homo-/bisexual men, injecting drug users, and female partners of HIV-infected men. Pulmonary Complications of Human Immunodeficiency Virus Infection Study Group.

OBJECTIVE: To study the overall and cause-specific HIV-related mortality in a cohort of HIV-seropositive subjects according to transmission category, race/ethnicity, sex and severity of immunosuppression. DESIGN: A cohort of 1129 HIV-seropositive homo-/bisexual men, injecting drug users, and female partners of HIV-infected men were enrolled at six centers in San Francisco, Los Angeles, Chicago, Newark, Detroit and New York between 1 November 1988 and 1 November 1989. Subjects were evaluated every 6 months at least until 31 March 1994. METHODS: The analyses of overall mortality for the subgroups of interest were performed with Kaplan-Meier plots and Cox proportional hazards models. Cause-specific analyses were performed on the primary cause of death using rates per 100 person-years of exposure. RESULTS AND CONCLUSIONS: Baseline severity of immunosuppression is the strongest predictor of mortality. There were no statistically significant differences in overall HIV-related mortality among transmission categories, race/ethnicity groups or sexes. There were differences, however, in cause-specific mortality among the different risk groups.

AIDS-Related Opportunistic Infections↗
PubMed1996

ZP3 peptide vaccine that induces antibody and reversible infertility without autoimmune oophoritis.

Autoantibodies to ZP3, a major glycoprotein of the zona pellucida (ZP) with sperm receptor function, can block sperm/oocyte interaction. However, only mice of certain major histocompatibility complex (MHC) haplotype respond to the ZP3 peptide. Moreover, ZP3-specific T cells can mediate ovarian autoimmune disease. A chimeric peptide has been designed that induces antibody to native ZP3 regardless of the MHC haplotype of the inbred mice tested. This results in reduction in fertility that is reversible. Infertility correlates well with ZP antibody titer, and the mice do not develop concomitant autoimmune oophoritis. The vaccine contains (1) a promiscuous foreign T-cell peptide capable of eliciting a T-cell response regardless of the animals' MHC haplotype, and (2) a modified native B-cell peptide of ZP3.

Animals↗