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Biomedical subjects

Fang Zhang

Publications and source records attributed to Fang Zhang.

At least 91 records · Page 5Linked to original sources
PubMed2003

Effects on breastfeeding of changes in maternity length-of-stay policy in a large health maintenance organization.

OBJECTIVE: The purpose of this study was to evaluate the effects on breastfeeding rates of a private-sector early discharge program and a subsequent government mandate guaranteeing 48 hours of hospital coverage. METHODS: Interrupted time-series analyses were conducted on retrospective data from the automated medical records of a large health maintenance organization in eastern Massachusetts. A population of 20 366 mother-infant pairs with normal vaginal deliveries between October 1990 and March 1998 was identified. This study period spanned the 2 interventions of interest: 1) the introduction of a new health maintenance organization protocol of 1 postpartum overnight hospitalization followed by a nurse home visit for normal vaginal deliveries, then 2) Massachusetts state minimum coverage legislation. Breastfeeding initiation and breastfeeding continuation among initiators (exclusive or with supplements) into the third month of life were determined through a text search of the first 90 days of infants' automated medical records. RESULTS: Both policies had dramatic impacts on length of stay (LOS); postpartum LOS <2 nights rose from 29% of pairs to 65% when the early discharge program was implemented, then fell to 15% after the state mandate. Breastfeeding initiation, however, rose gradually from 71% in the fourth quarter of 1990 to 82% in the first quarter of 1998, with no changes after the interventions. Continuation of breastfeeding among those who initiated remained constant at 73%. Younger maternal age, primiparity, low socioeconomic status, and nonwhite race all were found to be risk factors for lower rates of breastfeeding (either initiation or continuation), but there was no evidence of a decline in breastfeeding associated with shorter LOS among these vulnerable groups. CONCLUSIONS: Early postpartum discharge with outpatient breastfeeding support and a home visitor program has no adverse effects on initiation or continuation of breastfeeding.

Breast Feeding↗
PubMed2003

Refinement of heterozygosity loss on chromosome 5p15 in sporadic colorectal cancer.

AIM: To refine the loss of heterozygosity on chromosome 5p15 and to identify the new tumor suppressor gene (s) in colorectal tumorigenesis. METHODS: Sixteen polymorphic microsatellite markers were analyzed on chromosome 5 and another 6 markers were applied on chromosome 5p15 in 83 cases of colorectal and normal DNA by PCR. PCR products were electrophoresed on an ABI 377 DNA sequencer. Genescan 3.1 and Genotype 2.1 software were used for LOH scanning and analysis. RESULTS: We observed 2 distinct regions of frequent allelic deletions on Chromosome 5, at D5S416 on 5p15 and D5S428-D5S410 on 5q. Another 6 polymorphric microsatellite markers were applied to 5p15 and the minimal region of frequent loss of heterozygosity was established on 5p15 spanning the D5S416 locus. CONCLUSION: Through our detailed deletion mapping studies, we have found a critical and precise location of 5p deletions, 5p15.2-5p15.3, which must contain one or more unknown tumor suppressor gene (s) of colorectal cancer.

Adult↗
PubMed2003

[The effect of Chinese medicine yiqihuoxuetang on T-lymphocyte subpopulation in peripheral blood of infertile men with antisperm antibodies].

OBJECTIVES: To study whether Chinese Medicine Yiqihuoxuetang(YQHXT) could inhibit antisperm antibodies in infertile men, and to explore the therapeutical mechanism of YQHXT. METHODS: Thirty infertile men with antisperm antibodies took YQHXT continuously for 60 days. Indirect immuno-fluorescence technique (IFT) was used to detect the levels of CD3, CD4, CD8 and CD4/CD8 ratio before and after treatment. RESULTS: CD4 value and CD4/CD8 ratio after treatment were significantly lower than before treatment (P < 0.05); CD8 value became significantly higher(P < 0.05). CONCLUSIONS: The results indicated that YQHXT could inhibit antisperm antibodies by keeping the balance of T-lymphocyte subpopulation in immunoinfertile men.

Adult↗
PubMed2003

[A new vomiting animal model--mink].

AIM: To establish a new, reliable vomiting model in minks. METHODS: Adult male minks (Mustela vison) were randomly divided into groups (n = 6). Cisplatin, apomorphine, copper sulfate and X-radiation were used to establish vomiting model. Retching and vomiting were observed after the vomiting models were given anti-vomiting agents. After the behavioral experiment, assay of 5-HT in the ileum was performed by immunohistologic method. RESULTS: Cisplatin 7.5 mg.kg-1 i.p., apomorphine 1.6 mg.kg-1 s.c. and copper sulfate 40 mg.kg-1 ig were shown to evoke vomiting. Retching and vomiting were significantly inhibited in ondansetron and metoclopramide pretreated minks (P < 0.05, P < 0.01). CONCLUSION: As a new vomiting model, minks may be of great value in studying vomiting mechanism and screening new antiemetic drugs.

Animals↗
PubMed2003

[Detection technique of microsatellites polymorphism and its application in conservation genetics].

Microsatellites are a novel molecular genetic marker, and offer unusual advantages, e.g., with the using of a very few sample, they can be amplified by PCR, which are particularly appropriate in the research of conservation genetics. In this paper, the structure of microsatellites and the principle of the detection technique of microsatellites polymorphism were illustrated, and the advantages and the application of this detection technique were described briefly. For the isolation of microsatellite loci in animals, an enrichment method was introduced. And then, some practical problems of this technique were summarized.

Animals↗
PubMed2003

[Study on mortality, incidence and risk factors of stroke in a cohort of elderly in Xi'an, China].

OBJECTIVE: To prospectively study the relationship between risk factors and stroke incidence and mortality in the Chinese elderly. METHODS: An analytic study in a cohort population of 1,268 male retired cadres in a military setting. A health-screening program was carried out for all cadres aged 55 years or older in Xi'an in February 1987. Baseline data on smoking, cholesterol, triglyceride, blood pressure, body mass index (BMI), histories of hypertension, hyperlipidemia and coronary heart disease (CHD), stroke, diabetes and family histories of cardiovascular disease were investigated. Main outcome measures were stroke incidence, stroke and all-cause mortality. RESULTS: The cohort was followed up until June 30, 2001 and a total number of follow-up person-year was 15,546. During the follow-up period, there were 113 new stroke cases identified and the adjusted incidence was 727 per 100,000 person-year. Forty-five deaths were due to stroke and the adjusted mortality was 289 per 100,000 person-year. Using Cox model analysis, after adjustment on age, total cholesterol, triglyceride, smoking, drinking and physical exercise, we noticed that the systolic pressure, BMI, history of CHD and hyperlipidemia were independent risk factors for stroke incidence and morality. CONCLUSION: The incidence and mortality of stroke in this cohort were lower than those in the same age group of general population. Monitoring and controlling body mass index and blood pressure level seemed to be important factors for the prevention of stroke in the elderly.

Aged↗
PubMed2003

[Effects of enriched oxygen on human free radical metabolism during exercise at 5 380 m plateau].

OBJECTIVE: To study the effect of enriched oxygen on free radical metabolism at high altitude. METHOD: SOD, GSH-Px and MDA were measured in 10 health young men after step in a room with or without oxygen enrichment at high altitude of 5 380 m. RESULT: After exercise in the oxygen-enriched room, SOD and GSH-Px increased significantly while MDA decreased notably (P<0.01) than those after exercise in the room without oxygen enrichment (P<0.05 or P<0.01). CONCLUSION: Enriched oxygen can decrease damage from free radical at high altitude.

Adult↗
PubMed2002

Effects of a law against early postpartum discharge on newborn follow-up, adverse events, and HMO expenditures.

BACKGROUND: Concern about harm to newborns from early postpartum discharges led to laws establishing minimum hospital stays in the mid-1990s. We evaluated the effects of an early-discharge protocol (a hospital stay of one postpartum night plus a home visit) in a health maintenance organization (HMO) and a subsequent state law guaranteeing a 48-hour hospital stay. METHODS: Using interrupted-time-series analysis and data on 20,366 mother-infant pairs with normal vaginal deliveries, we measured changes in length of stay, newborn examinations on the third or fourth day of life, and office visits, emergency department visits, and hospital readmissions for newborns. We also examined expenditures for hospitalizations and home-based care. RESULTS: The early-discharge program increased the rate of stays of less than two nights from 29.0 percent to 65.6 percent (P<0.001). The rate declined to 13.7 percent after the state mandate (P<0.001). The rate of newborn examinations on the third or fourth day of life increased from 24.5 percent to 64.4 percent with the program (P<0.001), then dropped to 53.0 percent after the mandate (P<0.001)--changes that primarily reflected changes in the rate of home visits. The rate of nonurgent visits to a health center increased from 33.4 percent to 44.7 percent (P<0.001) after the reduced-stay program was implemented. There were no significant changes in the rate of emergency department visits (quarterly mean, 1.1 percent) or rehospitalizations (quarterly mean, 1.5 percent). Results were similar for a vulnerable subgroup with lower incomes, younger maternal age, a lower level of education, or some combination of these characteristics. Average HMO expenditures on hospital and home-based services decreased by $90 per delivery with the early-discharge program and increased by $100 after the mandate. CONCLUSIONS: Neither policy appears to have affected the health outcomes of newborns. After the mandate, newborns were less likely to be examined as recommended on day 3 or 4. Because of changes in hospital prices, the two policies had minimal effects on HMO expenditures for hospital and home-based services.

Adult↗
PubMed2002

Blockade of AP1 transactivation abrogates the abnormal expression of breast cancer-specific gene 1 in breast cancer cells.

Breast cancer-specific gene 1 (BCSG1) is not expressed in normal breast tissue but is highly expressed in the vast majority of invasive and metastatic breast carcinomas. When over-expressed, BCSG1 significantly stimulates the proliferation and invasion of breast cancer cells. The accumulated evidence suggests that the aberrant expression of BCSG1 in breast carcinomas is caused by transcriptional activation of the BCSG1 gene. However, the transcription factors that activate BCSG1 transcription have not been identified. In this study, we extensively investigated the role of AP1 in BCSG1 expression in breast cancer cells. We demonstrate that there are two closely located AP1 binding sites residing in the first intron of the BCSG1 gene. Mutation of either AP1 motif on the BCSG1 promoter constructs markedly reduces the promoter activity. We further show that 12-O-tetradecanoylphorbol-13-acetate (TPA) increases BCSG1 mRNA expression and up-regulates BCSG1 promoter activity through the intronic AP1 sites. The effect of TPA on BCSG1 transcription is also demonstrated under in vivo conditions in intact cells by using chromatin immunoprecipitation assays that show the TPA-induced binding of c-Jun to the chromatin region encompassing the intronic AP1 sites. Finally, to examine the direct effect of AP1 transactivation on BCSG1 expression, we established stable cell lines of T47D that express the dominant negative mutant of c-Jun, TAM67. RT-PCR and Western blot analyses demonstrated that levels of BCSG1 mRNA and protein in TAM67 transfectants were drastically reduced as compared with mock-transfected cells. Furthermore, inhibition of BCSG1 expression by blocking AP1 transactivation produced a similar repressive effect on cell growth as that by expressing BCSG1 antisense mRNA. We show that the anchorage-independent growth of T47D cells expressing either TAM67 or BCSG1 antisense mRNA is significantly inhibited. Taken together, we provide strong evidence that AP1 plays an overriding role in the transcription of the BCSG1 gene and that blockade of AP1 transactivation down-regulates BCSG1 expression and suppresses tumor phenotype.

Base Sequence↗
PubMed2002

Smoking, quitting, and mortality in a Chinese cohort of retired men.

PURPOSE: To examine the relationship between smoking, quitting, and mortality in older Chinese men. DESIGN AND METHODS: A cohort analytic study was carried out in Xi'an, China. A total of 1268 retired male military cadres aged 60 or older were examined in 1987 and followed for 12 years. RESULTS: At baseline, 388 men were never-smokers, 461 were former smokers, and 419 were current smokers. Through May 1999, a total of 299 had died. The relative risks [95% confidence intervals (CI)] for ever-smoking, after adjusting for age, blood pressure, body mass index, total cholesterol, triglycerides, alcohol drinking, exercise and existing diseases, for deaths resulting from all causes, chronic obstructive pulmonary disease (COPD), lung cancer, and coronary heart disease (CHD) were, respectively, 1.34 (1.02-1.76), 3.23 (0.95-10.91), 2.31 (0.95-5.61), and 1.60 (0.81-3.19). The risks increased significantly with increasing amount and duration of smoking. Compared with current smokers, former smokers had lower risks of total mortality (excess risk reduction of 56%) and from CHD death, but had higher risks for COPD death. CONCLUSIONS: Smoking is a major cause of death in older Chinese and quitting can save lives. Early recognition of the significance of COPD symptoms followed by prompt quitting should be emphasized in the control of the growing tobacco epidemic.

Aged↗
PubMed2002

Identification of Egr1 as the oncostatin M-induced transcription activator that binds to sterol-independent regulatory element of human LDL receptor promoter.

Previously, we identified the low density lipoprotein receptor (LDLR) promoter region -17 to -1 as a novel sterol-independent regulatory element (SIRE) that mediates the stimulating effect of oncostatin M (OM). The goal of this study was to identify the OM-induced transcription activator that binds to the SIRE sequence. By conducting a electrophoretic mobility shift assay (EMSA) followed by UV crosslinking and SDS-PAGE, we show that a protein with a molecular mass of 85 kDa was present in the OM-induced SIRE DNA-protein complex. Western blotting and supershift assays reveal that the 85 kDa factor is early growth response gene 1 (Egr1). The interaction of Egr1 with the SIRE sequence was further confirmed in vivo by chromatin immunoprecipitation assays. The functional role of Egr1 in LDLR transcription was assessed by cotransfection of an Egr1 expression vector with an LDLR promoter reporter construct. We show that overexpression of Egr1 significantly increases LDLR promoter activity when cotransfected with CCAAT/enhancer binding protein beta (c/EBPbeta) or with cAMP-responsive element binding protein (CREB) expression vectors. Our studies clearly demonstrate that Egr1 is the OM-induced transcription factor that binds to the SIRE sequence of the LDLR promoter and also suggest that Egr1 may have a functional role in OM-induced upregulation of LDLR transcription through interaction with other SIRE binding proteins such as c/EBPbeta or CREB.

DNA-Binding Proteins↗
PubMed2002

Variations of elemental distribution in brain regions of neonatal rats at different iodine intakes.

Iodine deficiency (ID) can result in irreversible damage to the brain during the fetal and neonatal stages. As the active center of many enzymes, trace elements play essential roles in brain function. In this work, the relative contents and distributions of elements (Cl, Br, Fe, Cu, and Zn) in two important brain regions, the cerebral cortex and hippocampus, of the iodine-deficient model rats were determined by the synchrotron radiation X-ray fluorescence (SRXRF) method. Meanwhile, the ID rats were supplemented with adequate and excessive iodine, respectively. The results indicated that the distributions of trace elements could be influenced by the different iodine intakes in the stage of brain development. In contrast to the control group, the contents of Cl, Br, and Zn in two brain regions showed a significant increase in the ID group; however, both Fe and Cu decreased in the cerebral cortex and increased in the hippocampus in the ID group. In addition, only slight changes of elemental contents in brain were found between the adequate and excessive iodine-supplemented rats.

Animals↗
PubMed2002

Loss of heterozygosity on long arm of chromosome 22 in sporadic colorectal carcinoma.

AIM: The loss of heterozygosity (LOH) on tumor suppressor genes is believed to play a key role in carcinogenesis of colorectal cancer. In this study, we analyzed the LOH at 5 loci on the long arm of chromosome 22 in sporadic colorectal cancer to identify additional loci involved in colorectal tumorigenesis. METHODS: Five polymorphic microsatellite markers were analyzed in 83 cases of colorectal and normal DNA by PCR. PCR products were eletrophoresed on an ABI 377 DNA sequencer; Genescan 3.1 and Genotype 2.1 software were used for LOH scanning and analysis. Comparison between LOH frequency and clinicopathological data were performed by chi(2) test. P<0.05 was considered as statistically significant. RESULTS: The average LOH frequency on chromosome 22q was 28.38 %. The region between markers D22S280 and D22S274 (22q12.2-q13.33) exhibited relatively high LOH frequency. The two highest LOH loci with frequencies of 35.09 % and 34.04 % was identified on D22S280 (22q12.2-12.3) and D22S274 (22q13.32-13.33). 8 cases showed LOH at all informative loci, suggesting that one chromosome 22q had been completely lost. On D22S274 locus, LOH frequency of rectal cancer was 50 % (9/18), which was higher than that of proximal colon cancer (12 %, 2/17) (P=0.018). The frequency of distal colon cancer was 42 % (5/12), also higher than that of proximal colon cancer. But there was no statistical significance. Putting both the tumors in distal colon and rectum together into consideration, the frequency, 47 % (14/30), was higher than that of proximal colon cancer (P=0.015),suggesting the mechanism of carcinogenisis was different in both groups. CONCLUSIONS: This study provided evidence for the involvement of putative tumor suppressor genes related to the sporadic colorectal carcinoma on chromosome 22q. The tumor-suppressor-gene(s) might locate on the 22q12.2-12.3 and/or 22q13.32-13.33.

Adult↗
PubMed2002

Inhibitory effects of succinic acid on chemical kindling and amygdala electrical kindling in rats.

AIM: To investigate the effects and mechanism of succinic acid on pentylenetetrazol (PTZ) chemical kindling and amygdala electrical kindling in rats. METHODS: PTZ chemical kindling and amygdala electrical kindling models were established in rats. The effects of succinic acid on the behavior and afterdischarge of kindled rats were observed. The mice were pretreated with succinic acid, 30 min later, picrotoxin, a GABAA receptor antagonist was given by ip, then the effects of succinic acid on mice were observed. RESULTS: Succinic acid (100-400 mg/kg, ip) dose-dependently inhibited PTZ chemical and amygdala kindled seizure (P<0.05, P<0.01), elevated the afterdischarge threshold, and reduced the Racine's stage of amygdala kindling rats (P<0.05, P<0.01); succinic acid (200-400 mg/kg, ip) inhibited picrotoxin-convulsion in mice (P<0.05, P<0.01). CONCLUSION: Succinic acid inhibits PTZ chemical and amygdala electrical kindling in rats, and the inhibition mechanism may be related to the enhancement of GABAergic system action in the brain, especially through GABAA receptors.

Amygdala↗
PubMed2002

[A prospective study on smoking, quitting and mortality in a cohort of elderly in Xi'an, China].

OBJECTIVE: To prospective examine the relationship between smoking, quitting and mortality in older Chinese men by in Xi'an, China. METHODS: The design was a cohort analytic study. One thousand two hundred and sixty-eight retired male military veterans aged 60 or older were examined in 1987. At baseline, there were 388 never-smokers, 461 former smokers and 419 current smokers. Main outcome measure was all-cause and tobacco-associated mortality. RESULTS: Through 1999, 299 had died, 943 were alive and 26 lost. The mean follow-up time was 11 years and total person-year of follow-up was 14 163. After adjusting for age, blood pressure, body mass index, total cholesterol, triglycerides, alcohol intake, exercise and existing diseases, using Cox proportional hazard regression model, the relative risks (95% confidence intervals) for ever-smoking, deaths resulting from all causes, chronic obstructive pulmonary disease (COPD), lung cancer and coronary heart disease (CHD) were 1.34 (1.02 - 1.76), 3.23 (0.95 - 10.91), 2.31 (0.95 - 5.61) and 1.60 (0.81 - 3.19) respectively. The risks increased significantly with increasing amount and duration of smoking. Compared with current smokers, former smokers had lower risks of total mortality (excess risk reduction of 56%) and from CHD death (93%), but had higher risks for COPD death (excess risk increased 174%). CONCLUSIONS: Smoking is a major cause of death in older Chinese men and quitting can save lives. These results showing that higher risks of COPD death in former smokers with or without existing diagnosed COPD at baseline than those in current smokers could be explained by either the "healthy smoker effect" or the "ill quitter effect" or both. Early recognition of the significance of COPD symptoms followed by prompt quitting should be emphasized as strategies in the control of the growing tobacco epidemic.

Aged↗
PubMed2002

[Allelic analysis on chromosome 5 in sporadic colorectal cancer patients].

OBJECTIVE: To evaluate and map the putative tumor suppressor loci on chromosome 5 involved in tumor progress or metastasis. METHODS: Chromosome 5 of 83 patients with sporadic colorectal cancer was systemically screened. Fifteen microsatellite marker primers labeled with 3 different fluorescents were used to amplify the corresponding loci of the genome DNA. The PCR products were electrophoresed on a 377 PRISM sequencer and the fluorescent signals were analyzed with Genotyper and Genescan software. RESULTS: The highest loss of heterozygosity (LOH) ratio was found at D5S416 (48.15%) on 5p and at D5S471 (38.71%) on 5q. The region (5q13.3 - 31), where D5S471 and 3 neighboring loci (D5S428, D5S2027 and D5S2115) reside, presented high frequent LOH. CONCLUSION: The deletion of APC, MCC, CTNNA1 and IL cluster in the 5q 13.3 - 31.1 area play important role in the tumorogenesis of colorectal cancer, and the expected existence of another novel tumor suppressor gene on 5p is possible.

Adult↗
PubMed2002

[Loss of heterozygosity analysis to define putative region involved in tumor differentiation and metastases in sporadic colorectal cancer patients].

OBJECTIVE: To detect putative suppressor loci involved in tumor progressing or metastases. METHODS: Thirty microsatellite marker primers were employed to amply the corresponding loci of the genome DNA from 83 patients with sporadic colorectal cancer. The PCR products were electrophoresed on a 377 PRISM sequencer and the fluorescent signals were analyzed by Genotyper and Genescan software. RESULTS: The data were obtained from 24 loci, with an average LOH frequency of 15.16%. The LOH at D2S206 and D2S364 was more frequent than 30%, and was less than 20% at the rest loci. Significant difference was observed between the percentage of LOH and tumor staging or differentiation at D2S142 (2q24.1), D2S126 (2q35), D2S2211 (2p24.2), D2S305 (2p23.3). Occarrence of deletion at the later two loci was correlative. CONCLUSIONS: Frequent LOH was not observed at the loci around known mismatch repair genes on chr. 2. The region between D2S305 (2p23.3) and D2S2211 (2p24.2) deleted holistically, and was correlated to the stage and differentiation of tumor attended by D2S142 (2q24.1) and D2S126 (2q35) on 2q. It is suggested that unknown genes associated with tumor progressing or metastases reside in the two loci on 2q or the region on 2p.

Adult↗