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Biomedical subjects

Y Zhu

Publications and source records attributed to Y Zhu.

At least 199 records · Page 11Linked to original sources
PubMed2001

PPP2R1B gene in chronic lymphocytic leukemias and mantle cell lymphomas.

Deletion of chromosome bands 11q22-q23 is one of the most common structural chromosome alterations in chronic lymphocytic leukemia (CLL) and mantle cell lymphoma (MCL). The PPP2R1B gene is located very close to the minimal common deletion region of 11q22-q23 in CLL and MCL. Recently, the PPP2R1B gene was found to be mutated in human lung and colon cancers. To evaluate the role of the PPP2R1B gene in the pathogenesis of CLL and MCL, we performed RT-PCR analysis and cDNA sequencing on 10 CLL RNA samples and SSCP analysis on 26 CLL and 37 MCL genomic DNA samples. A deletion of exon 3 was found in one CLL sample. No mutation was detected in the SSCP analysis. To exclude the possibility of large genomic deletions we performed Southern blotting analysis. One MCL sample showed abnormal bands. Our results do not suggest that the PPP2R1B gene has a major pathogenic role in CLL and MCL.

Base Sequence↗
PubMed2001

Identification of the epitopes on HCV core protein recognized by HLA-A2 restricted cytotoxic T lymphocytes.

AIM: To identify hepatitis C virus(HCV) core protein epitopes recognized by HLA-A2 restricted cytotoxic T lymphocyte (CTL). METHODS: Utilizing the method of computer prediction followed by a 4h(51)Cr release assay confirmation. RESULTS: The results showed that peripheral blood mononuclear cells (PBMC) obtained from two HLA-A2 positive donors who were infected with HCV could lyse autologous target cells labeled with peptide "ALAHGVRAL (core 150-158)". The rates of specific lysis of the cells from the two donors were 37.5% and 15.8%, respectively. Blocking of the CTL response with anti-CD4 mAb caused no significant decrease of the specific lysis. But blocking of CTL response with anti-CD8 mAb could abolish the lysis. CONCLUSION: The peptide (core 150-158) is the candidate epitope recognized by HLAA2 restricted CTL.

Amino Acid Sequence↗
PubMed2001

Up-regulation of transcription of smooth muscle myosin alkali light chain by ethanol in human breast cancer cells.

Both epidemiological and experimental studies indicate that ethanol is a tumor promoter and that chronic ethanol exposure enhances metastasis of breast cancer cells, and with an in vitro model (T47D human breast cancer cells), we have previously demonstrated that ethanol exposure stimulated the migration of breast cancer cells. In the present study, differential display reverse transcription polymerase chain reaction was used to identify ethanol-responsive genes in T47D cells. Three differentially displayed, ethanol-responsive gene fragments were identified, and their expression was confirmed by Northern blot hybridization. Sequence analysis revealed that one cDNA fragment represented the myosin alkali light chain (MLC 1sm) of human smooth muscle. The expression of MLC 1sm was found to be significantly higher in breast cancer cells than in normal mammary epithelial cells. With T47D cells, ethanol induced an additional duration- and concentration-dependent up-regulation of MLC 1sm. At 400 mg/dl, an ethanol-mediated increase was evident at 6 h (55% increase), peaked at 24 h (2.7-fold increase) following exposure, and diminished thereafter. At pharmacologically relevant concentrations (e.g., 100 mg/dl), ethanol produced a significant increase of MLC 1sm expression, and progressively higher ethanol concentrations resulted in more up-regulation. The half-life of MLC 1sm mRNA was not altered, however, the transcription rate of MLC 1sm was significantly increased by ethanol. MLC is a structural component of the cytoskeleton of eukaryotic cells, and it plays critical roles in the regulation of cell shaping, movement, and growth. Thus, ethanol-mediated up-regulation of MLC may be an underlying molecular mechanism for its tumor promoting effect.

Blotting, Northern↗
PubMed2001

The effect of attenuated varicella-zoster virus on replication of HBV.

OBJECTIVE: To observe the effect of attenuated varicella-zoster virus (VZV) on replication of HBV in vitro and vivo. METHODS: The attenuated VZV were inoculated into the ducks infected with DHBV and into the cultural HepG(2) 2.2.15 cells, respectively. DHBV DNA, HBsAg and HBeAg were detected from the duck serum and cell cultural fluid by dot-blot hybridization and EIA. RESULTS: The decline of DHBV DNA in duck serum was found in two dosage groups. Compared with pre-treatment, the level of AD value in 200 pfu/kg group was significantly decreased from 1.17+/-0.29 to 0.59+/-0.45 (10 day after VZV treatment) and 0.21+/-0.21 (5 day after withdrawal of VZV)(t =3.51, 7.54, P<0.001). The level in 400 pfu/kg group was from 0.70+/-0.25 to 0.32+/-0.17 on the 5th day of withdrawal of VZV (t =3.58, P<0.01), respectively after treatment. The inhibitory rates of HBeAg and HBsAg were 61% and 33%, respectively. The effect on HBeAg seems to be more obvious than on HBsAg. CONCLUSIONS: Attenuated VZV could significantly decrease serum DHBV DNA in DHBV-infected ducks and directly inhibit the HBeAg and HBsAg secreted by 2.2.15 cells, suggesting that VZV seems to interfere or inhibit the replication of DHBV.

Animals↗
PubMed2001

[Measurement of formaldehyde in disinfectant with spectrophotometry].

Formaldehyde in disinfectant was measured by acetylacetone spectrophotometry. The regression equation was linear when the formaldehyde concentration was smaller than 10 micrograms/ml. The detection limit was 0.08 microgram/ml. The accuracy was less than 3.9% and the recovery varied between 100.2%-108.2% for formaldehyde disinfectant with different concentration, which was similar to titrimetry. It was demonstrated that the method was simple, reproducible, sensitive, precise and accurate, making it important for assay of formaldehyde in disinfectant when disturbance caused titrimetry unavailable.

Disinfectants↗
PubMed2001

[Phosphorus loss potential of soil-water in sites of the main rice-yield area in the Northern Zhejiang].

Phosphorus (P) loss potential and its environmental impact from soil-water were surveyed in Jiashan Yuyao, Deqing and Yuhang, named main rice-yield areas in Northern Zhejiang province China. High P input has resulted in soil P accumulation. Higher soil Olsen-P contributed its bio-available P, water extracted P and increased soil P loss potential. The role of P in paddy soils is of environmental rather than agronomic concern in the process of soil P build-up. During the no-rice time, total P (TP) concentration in the various water including ditch drain inside/outside field, field surface water and pipe drain et al are over the critical values associated with accelerated waters eutrophication. The average proportion of dissolved reactive P (DRP) concentration in TP was 40%, however, these current DRP levels in partly ditch drain outside field and surface or ground water in no-rice time could not caused serious impact to the outside waters nearby rice-yield agriculture area. No significant line correlation between soil P tests and P in field surface water was found in no-rice time due to differences in field tillage among rice-yield areas, while P application increased both soil P and its correspondingly field surface P level after rice was planted at the same time.

Oryza↗
PubMed2001

[Preparation, characterization and characteristics of copolypeptide consisting of L-aspartic acid and L-glutamic acid].

For the purpose of increasing the hydrophilicity of poly-aspartic acid, a copolypeptide consisting of L-aspartic acid and L-glutamic acid (8: 2 mol/mol) was prepared. The copolymer was characterized by 1H NMR, 13C NMR, differential scanning calorimetry, X-ray and element analysis. 3-hydroxyamino, as a side chain, was linked to the polymer, and poly-(3-hydroxypropyl)-L-aspartamide-L-glutamide (PHPAG) was obtained. The molecular weight of PHPAG was determined by GPC. Tests of the PHPAG on laboratory animals corroborated its potential use as a drug carrier. Acute toxicity studies revealed no death in animals treated, other studies recorded no notable difference between treated and control animals either in terms of principal haematological parameters or in micronucleus test. In vitro enzymatic hydrolysis for the co-polymer was performed using chymotrypsin, fungi protease and trypsin. It showed that these proteins could degrade the copolymer to some degree. The effects of pH, light and humidity on PHPAG were also investigated. The results indicated that it was stable under the experiment conditions.

Animals↗
PubMed2001

Glucocorticoid receptor and heat shock protein 90 in peripheral blood mononuclear cells from asthmatics.

OBJECTIVE: To investigate the expression of glucocorticoid receptor (GR) and heat shock protein 90 (HSP90) mRNA in peripheral blood mononuclear cells (PBMCs) from steroid-sensitive (SS), steroid-dependent (SD) and steroid-resistant (SR) asthmatics patients, and to evaluate the role of GR and HSP90 in the pathogenesis of SR. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) was used to determine the expressions of GR and HSP90 mRNA in PBMC stimulated with IL-2 and/or IL-4 from 10 normal volunteers, 10 SS, 5 SD and 6 SR patients. RESULTS: The expressions of GR and HSP90 mRNA were the highest in PBMC from SR patients (0.730 +/- 0.171 and 1.122 +/- 0.165, respectively) compared with the normals (P < 0.05). The second was from SS patients (0.359 +/- 0.350 and 0.885 +/- 0.250, respectively). The lowest was from the SD patients (0.017 +/- 0.008 and 0.078 +/- 0.039, respectively). The ratio of HSP90/GR in SR was significantly lower than that in the others, and it suggested that the expression of HSP90 mRNA was not sufficient in this group of patients. When PBMC from SS, SD and SR was incubated with IL-2 or IL-4 alone, no changes in GR and HSP90 mRNA expression were observed. While incubated with combination of IL-2 and IL-4, a significantly higher expression of GR mRNA was observed in all asthmatics, and a significantly higher expression of HSP90 mRNA was observed only in SS and SD patients. CONCLUSION: The lowering of HSP90/GR ratio may be one of the causes of SR. IL-2 and IL-4 may play roles in the imbalance of HSP90/GR.

Adult↗
PubMed2001

[The association of methylenetetrahydrofolate reductase gene polymorphism with nephropathy in type 2 diabetes mellitus in Chinese].

OBJECTIVE: To evaluate the role of methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms in Chinese patients with type 2 diabetes mellitus and diabetic nephropathy(DN). METHODS: 85 type 2 diabetes mellitus patients and 57 controls were recruited in the study. MTHFR genetic C677T polymorphism was determined with PCR-restriction fragment length polymorphisms (RFLP). Plasma total homocysteine level was measured using high-performance liquid chromatography (HPLC) with fluorescence detection. RESULTS: The frequency of MTHFR TT homogenetic type and CT heterogenetic type and allele T(28.21%, 51.28%, 53.85%) was significantly higher in type 2 diabetes mellitus with diabetic nephropathy group than those without nephropathy (19.57%, 28.26%, 33.70%) or normal controls (17.54%, 28.07%, 31.58%). However, there was no significant difference of MTHFR genotype and allele frequency between type 2 diabetes mellitus without nephropathy and normal controls. The presence of T allele appeared to have a stronger association with the development of diabetic nephropathy. The odds ratio was 2.30 and the 95% confidence interval was 1.24-4.26. Moreover, plasma homocysteine levels were markedly higher in patients with TT or CT genotype than those in patients with CC genotype. CONCLUSIONS: MTHFR gene C677T mutation associated with a predisposition to increased plasma homocysteine levels may represent a genetic risk factor for diabetic nephropathy in Chinese type 2 diabetes mellitus.

Adult↗
PubMed2001

[Phosphorus behavior in soil-water system of paddy field and its environmental impact].

A field experiment with rice showed that P fertilizer application increased the concentrations of resin P in soil and total P in soil surface water, and both of them declined subsequently over time. Compared with applying mineral P fertilizer only, the integrated application of mineral-P and manure resulted in a higher resin P level within 20 days after P application. The total P concentration in soil surface water in the treatment of integrated application of mineral-P and manure was 3.4 times higher than that in the treatment of mineral-P fertilizer application only after 7 days of P application, and also, was 2.8 times higher than that in the treatment where P application rate was doubled. The potential of Ploss from surface water in the treatment of integrated application with manure was more than that in the treatment of applying-P fertilizer only. The effect of applied P sorts on P concentration in soil surface water could be ignored after 33 days of P application. Two drainages were conducted for rice growth, which caused the net P loss loading and its apparent P loss ratio in range of -0.038-0.076 kg.m-2 and 0.034-0.100%, respectively. To minimize P loss from rice production area, field drainage should be avoided in the initial week of P-fertilizer application or field harrowing.

Environment↗
PubMed2001

[Significance on expressions of Annexin-I and its correlative gene proteins in endometrial hyperplasia, atypical hyperplasia and endometrial carcinoma].

OBJECTIVE: To investigate expression of Annexin-I in various endometrial lesions and its significance in differential diagnosis of endometrial borderline lesions. METHODS: We collected 37 specimens with different endometrial lesions, and reclassified them according to China and FIGO's standard, which included 12 cases of endometrial hyperplasia (EH), 10 cases of atypical hyperplasia (ATH) and 15 cases of endometrial carcinoma (EC). Immunohistochemical staining for AX-I, c-erbB-2, p53 protein, ER, PR, EGF and IGF were performed by LSAB. RESULTS: The results showed that for AX-I, 1 cases of EH was weakly positive and others were negative; 9 cases of ATH showed strong positivity in the cytoplasm and the cell membrane, and 1 weakly positive; 7 cases of EC were positive and 8 negative. c-erbB-2 was expressed in 9 cases of ATH and 1 was negative. Expressions of EGFR, ER and PR were strong in all cases, but IGFR was negative in almost all cases. P53 expression was higher in EC than in ATH. CONCLUSIONS: AX-I expression suggests that (1) AX-I protein may play an important role in the pathogenesis of cancer, the expression decreased and disappeared after malignant change. (2) High expression for AX-I can be used to differentiate ATH and EC. In addition, c-erbB-2 expression appeared to parallel the expression of AX-I in both ATH and EC, but in ATH it was higher than that in EC.

Annexin A1↗
PubMed2001

[Genetic epidemiology and HLA survey of primary hemochromatosis among Chinese Miao ethnic].

OBJECTIVE: To evaluate the inheritance modes and the genetic factors of primary hemochromatosis on its etiology among throngs of Chinese Miao nationality in causing the disease and to study the relation between the relevant susceptible gene and HLA linkage. METHODS: To investigate of the genetic epidemiology among some throngs of pure Miao nationality in western Human and the neighbouring areas was carried out and analysis of identical HLA haplotype and Lods was made. RESULTS: The population morbidity of this disease in this area is 0.48%. Twenty-four patients found in four families had high plasma glucose levels, and apparently high serum total iron and serum transferrin. The prevalence of hemochromatosis was 44.45% by analysis on the first degree and second degree relatives of the 24 patients. The individual marking of HLA ranges from locus A1, A2 to A3. CONCLUSION: HLA haplotype shows obvious deviation from random distribution, which indicates that there exists linkage between HH pathogenic gene and HLA. The results of genetic analysis in this disease group suggest that hemochromatosis is an autosomal dominant inheritance but not autosomal recessive inheritance disease.

Adolescent↗
PubMed2001

[Antisense RNA for urokinase receptor inhibits the invasiveness and metastasis of lung carcinoma].

OBJECTIVE: To inhibit invasion and metastasis of human lung carcinoma cell line 95D by antisense RNA for urokinase receptor (uPAR). METHODS: Antisense RNA expression plasmid for uPAR was introduced into the highly metastatic human lung carcinoma cells 95D. Modified Boyden's chamber was used to detect the invasion ability, and nude mice were used to determine metastasis. RESULTS: Two transfected clones were found to integrate the antisense expression plasmid into genomic DNA and to express antisense RNA for uPAR. Antisense RNA blocked the uPAR expression in the transfected clones. The evident reductions of the invasiveness of antisense clones were observed by comparison with control cells, 95D cells and cells transfected with pcDNA3 vector. The metastatic potential of these two antisense clones decreased significantly in comparison with the controls (P < 0.05). CONCLUSIONS: The results suggest that antisense RNA for uPAR inhibits uPAR expression and leads to a decrease of metastatic potential of 95D cells. Antisense RNA technique may have a valuable application in anti-metastatic therapy of human lung carcinoma.

Animals↗
PubMed2001

Detection of p53 gene mutations in sputum samples and their implications in the early diagnosis of lung cancer in suspicious patients.

OBJECTIVES: To evaluate the value of detecting p53 gene point mutations in sputum samples and its validity and reliability as a surveillance index in the early diagnosis of lung cancer in suspicious patients. METHODS: Sputum samples were collected from 54 cases identified as lung cancer and 114 cases identified as pulmonary benign disease. The polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was performed for the detection of point mutations at exons 5-8 of the p53 gene, and sputum smears were also used for each sample. RESULTS: The detected mutation rate of 55.56% (30/54) in the lung cancer group was significantly higher than that of 1.75% (2/114) in the control group (P < 0.001). In the lung cancer group, the sensitivity, specificity, and positive likelihood ratio (PLR) of p53 mutations as a diagnostic marker for lung cancer were 55.56%, 98.25% and 31.75%, respectively. Also, the detection rates were 35.19% (19/54) by smears and 55.56% (30/54) by PCR-SSCP-silver stain, respectively. The differences both in rate and consistency were statistically significant (P < 0.01 and P < 0.05, respectively). Moreover, statistical analysis showed no significant relations between p53 mutations and clinical parameters such as gender, smoking habits, histotypes and stages, but the detection rate of p53 mutations in older patients (> or = 60 years old) was significantly higher than that in younger patients (P = 0.02). One case with p53 mutations at exon 5 in the control group was confirmed to be squamous cell carcinoma after 4 years of follow-up. CONCLUSION: Detection of p53 gene alterations in sputum samples by PCR-SSCP-silver stain can be used as a follow-up surveillance index for the early diagnosis of lung cancer in suspicious patients.

Adult↗
PubMed2001

[The role of plasma placental isoferritin in pathogenesis of preeclampsia and its predictive value for preeclampsia].

OBJECTIVE: To investigate the effect of placental isoferritin in pathogenesis of preeclampsia and its predictive value. METHODS: A prospective double-blinded study was performed. There were 120 initial normal pregnant women at earlier third trimester (from 24 to 34 weeks) in this study. Their plasma placental isoferritin and nitric oxide (NO) metabolites (nitrite/nitrate) (NO2-/NO3-) were examined by enzyme linked immunoabsorbent assay (ELISA) and Griess assay respectively. The outcomes of pregnancies were followed up. RESULTS: In 120 initial normal pregnant women, 19 pregnant women occurred preeclampsia (preeclampsia group), and 101 cases were normal (normal group) at follow up. The levels of plasma placental isoferritin (PLF) were significantly decreased in preeclampsia group (285.31 +/- 53.73 mg/L) than that of normal group (699.05 +/- 203.03) mg/L, P < 0.01. The levels of plasma NO were significantly increased in preeclampsia group (54.57 +/- 32.71 mumol/L) than that of normal group (38.89 +/- 30.00) mumol/L, P < 0.05. The significant negative correlation between the plasma placental isoferritin and NO levels was observed(r = 0.329, P < 0.01). At the cut point of 400 mg/L PLF level, the sensitivity, specificity, positive predictive value, negative predictive value and Kappa index of PLF level predicting on the outcomes of pregnancy with preeclampsia were 100%, 85.15%, 55.88%, 100%, 0.645. CONCLUSIONS: The decrease of plasma placental isoferritin levels is associated with preeclampsia, and the endothelial cell damage may be one of its mechanism. The PLF may be an earlier predictor of preeclampsia at 24-34 gestational weeks.

Adult↗
PubMed2001

[Analysis of factors influencing the clinical in a frozen thawed embryo transfer program].

OBJECTIVE: To analyze the factors influencing the outcome in a frozen thawed embryo transfer (FTET) program. METHODS: Sixty FTET cycles performed in 53 cases from September 1997 to May 2000 were analyzed retrospectively. The related parameters were compared between the conceived and non-conceived cycles. RESULTS: One hundred and seventy eight out of 252 thawed embryos were survival. Embryo transfers were undergone in 57 cycles (53 patients), resulting in 17 pregnancies (30% per transfer or 28% per thawed cycle). There were no significant difference between conceived and non-conceived cycles in terms of the controlled ovarian hyperstimulation protocols, numbers of developed follicle and oocyte retrieved, fertilization rate, numbers of frozen embryo and the luteinizing hormone, estradiol, progesterone levels on human chorionic gonadotropin triggering day. The percentage of good quality embryo before freezing and after thawing and survival thawed embryos were higher in conceived cycles than those in non-conceived cycles (83.8% Vs 60.7%, 76.8% Vs 50.0%, 82.4% Vs 66.3%, respectively P < 0.05). CONCLUSIONS: Good quality of frozen-thawed embryos and the trilaminar sonographic pattern of endometrium may be reliable predictors of success in pregnancy.

Cryopreservation↗