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Biomedical subjects

Z Fang

Publications and source records attributed to Z Fang.

At least 145 records · Page 8Linked to original sources
PubMed1997

Repression of gonadotropin-releasing hormone promoter activity by the POU homeodomain transcription factor SCIP/Oct-6/Tst-1: a regulatory mechanism of phenotype expression?

POU domain transcription factors are required for neuropeptide expression in selected subsets of hypothalamic neuroendocrine neurons. We now report that expression of the gonadotropin-releasing hormone (GnRH) gene, which controls sexual development, is regulated by the POU protein SCIP/Oct-6/Tst-1. Reverse transcriptase PCR cloning and RNase protection assays demonstrated the presence of SCIP/Oct-6/Tst-1 mRNA in the GnRH-producing neuronal cell line GT1-7. The physiological relevance of this regulatory activity was suggested by the detection of SCIP/Oct-6/Tst-1 mRNA in a subset of GnRH neurons in the hypothalamus of prepubertal female rats. Coexpression of SCIP/Oct-6/Tst-1 in neuronal cells inhibited rat GnRH (rGnRH) promoter activity via three regions of the proximal rGnRH promoter containing SCIP/Oct-6/Tst-1 binding sites. DNase I footprinting, gel shift assays, and DNA and protein mutagenesis studies indicated that both direct DNA binding and protein-protein interactions are required for SCIP/Oct-6/Tst-1 modulation of GnRH gene expression. Activation of SCIP/Oct-6/Tst-1 expression in terminally differentiated GnRH neurons may be a factor determining the ratio of phenotypically "inactive" versus "active" GnRH neurons during postnatal life.

Animals↗
PubMed1997

[Pathological type of liposarcoma and its effects of clinical treatment].

To study the pathological type of liposarcoma and it effects of clinical treatment, reviewed 21 cases of liposarcoma. Since Oct. 1976 to Dec. 1995, 21 cases of liposarcoma were treated by operation. 15 cases were male and 6 cases female. The onset of the disease occurred between 6-79 years of age with an average of 49.9 years. 13 cases were well-differentiated, 4 Myxoid, 4 cases of andifferentiaed. All cases were followed up with an average of 8.9 years. The 5-, 10-year survival rate was 94%, the 5-, 10-year unrecurernce rate was 72% and 52%. Among the malignant soft tissue tumors liposarcoma, was most common. The survival rate was related to the pathological type, the site and the size. Good clinical results were well-differentiated and myxoid. The poor was retroperitoneal liposarcoma. The smaller the tumor, the better the result. For the treatment, wide margin excision is a good method of choice.

Adolescent↗
PubMed1997

[The identification of banding chromosomes by computer image analysis].

The analysis system for banding chromosomes (SYSTEM), an image analysis software, was programmed. By the SYSTEM the photos of Chinese G banding chromosomes were analyzed. It showed that the karyotype of the chromosomes of persons was recorded in high speed and efficiency, and that the chromosomes of alike ordinal number from different persons could be compared directly. That would presage, by this kind of the high effective operation, a favorable condition was created for the application of the polymorphism of the chromosomes to the parentage diagnosis.

Chromosome Banding↗
PubMed1997

[Immunogenecity of expressed protein p68 from recombinant plasmid rpDJt in L. interrogans serovar lai].

There are two types of infection caused by pathogenic microorganisms, intracellular infection and intercellular infection. Infection of pathogenic leptospira is an intercellular infection. The immunological reaction of host to intercellular infection is unique. The potential immunogen of an expressed protein should meet three criteria: it can be degraded (by antigen-present cells in the host); it should have antigenic epitope which can be recognized by specific antibodies and have at least one epitope that can be recognized by an MHC II protein and T cell receptor. In this study we report the cloning of an L. interrogans protein in plasmid rpDJt and the immunogencity of the expressed protein derivative. A genomic library of L. interrogans serovar lai strain 017 was constructed with the plasmid vector pUC18. Recombinant plasmids, designated pDJH2 and pDJ8 were screened from the bank. EcoRI-inserted fragment of 1. 9 kb recombinant DNA of pDJH2 was ligated into T7 RNA polymerase/promoter vectors (pT7-7). Then they were transformed into E. coli JM109 (De3), one of subclones, designated rpDJt was achieved. SDS-PAGE showed that the molecular weights of expression proteins were 68 kd and 23 kd respectively, designated p68 and p23. Purifying and isolating p68 and p23, we separated them from SDS-Polyacrylamide gels by using Side-Strip method. After fragmenting and electroeluting, p68 and p23 were injected into guinea pigs and rabbits. An extremely strong immune response to p68 was obtained since an anti-p68 antibody response could be detected to a dilution 1:524,288 (guinea pigs) and 1:262,144 (rabbits) by ELISA while anti-P23 antibody being 1:1024 (the same to guinea pigs and rabbits). The results of improved MTT and conA 3HTdR transformation methods showed the activities and proliferation of Th-cells were increased in guinea pigs after p68 immunization (IL-6, 83.25 IU/ml, IL-2, 28.75 IU/ml; RPI, 2.04, SI, 65.62%) Thlymphocyte existed in two subclasses, the Th1- and Th2-cells. A major role of Th2-cells is to "help" B-cells differentiate, replicate, and secrete antibody. The properties of these interactions explain why p68 makes good antigen and p23 does not. The antigens responsible for eliciting the production of protective antibodies are not known; however, several outer membrane proteins on L. interrogans are candidates for vaccine. Our results suggest that expresion protein p68 from recombinants (rpDJt) may be a candidate for gene engineered subunit vaccine for Leptospirosis.

Animals↗
PubMed1997

[Construction of genomic library of L. interrogans serovar lai using lambda gt11 as the vector and a study of recombiant plasmid pDL121].

A genomic library of L. interrogans serovar lai strain 017 has been constructed using lambda gt11 as the vector. DNA was partially digested by two blunt-end restriction enzymes, then methylated with EcoR I methylase; after EcoR I linker was added to the DNA, the linker-ended DNA was ligated to the dephosphorylated EcoR I digested lambda gt11 arms. The recombined DNA was packaged in vitro, and used to transduct E. coli Y1090 for amplification. There were 2.1 x 10(6) recombinant bacteriophages as recognized by their ability to form white plaques plated on Lac host in the presence of both IPTG and X-Ga1. A positive clone, designated lambda DL12, was screened with a rabbit anti-serum against L. interrogans serovar lai from the genomic library. The DNA from lambda DL12 was subcloned into plasmid pUC18. A recombinant (designated as pDL121) was obtained. SDS-PAGE analysis indicated that a 23 kd was expressed in E. coli JM 103 harboring pDL121. Western blotting analysis showed that a specific protein band molecular weight of 23 kd could be recognized by the rabbit antiserum against L. interrogans serovar lai strain 017.

Cloning, Molecular↗
PubMed1997

[The technology of real time telemetring and monitoring multi-channels ECGs through public telephone network].

In this essay a kind of technology of real time telemetring and monitoring multi channels ECGs through public telephone network is presented. Two limb leaders (I and II) ECG signals are transmitted from the sender at first. After they are received by the receiver the other four limb leaders are calculated by computer in the basis of the relation among the limb leaders, the received waveform and the calculated waveform are just the same as those described directly by Electro Cardiograph. After the limb leaders ECG signals (34 s) are transmitted, two selectable thorax leaders ECG signals are transmitted for 34 seconds after automatically changing the leaders. The received ECG waves are displayed on screen real time, shifting smoothly. After transmission doctors may make diagnoses and give some suggestion for treatment. Thus, telemetrying and monitoring multi channels ECGs is realized.

Electrocardiography↗
PubMed1997

[The development of ECG trans-telephone popular monitoring system].

In this essay a new kind of ECG telemetry and monitoring system based on public telephone network is presented, which is able to transfer four channels of ECG of two patients to monitoring center sited at hospital synchronizingly. At the same time doctors may make diagnosis and give instruction for treatment. The system has the functions of real time sample, reviewing, freezing, store, windows, and printing, etc.

Electrocardiography↗
PubMed1997

[Vertical transmission of hepatitis C virus].

To study the transmission of hepatitis C virus (HCV) from infected mother to their infants, out of 1047 mothers studied, 8 were anti-HCV antibody and 6 were HCV RNA positive as well as 2 mothers who were anti-HCV antibody and HCV RNA positive. 12 mothers and their 12 babies were followed up for 12 months. Only one of 12 infants showed persistently positive for anti-HCV antibody and HCV RNA at 1, 6 and 12 months of age. His HCV type was identical to his mother. These results suggest that vertical transmission is present but not an important route for HCV infection.

Adult↗
PubMed1997

[Pharmacokinetics of intravenous arsenic trioxide in the treatment of acute promyelocytic leukemia].

OBJECTIVE: In order to study the pharmacokinetics and metabolism of arsenic trioxide (As22O3), and its major side effects. METHODS: The clinical pharmacokinetics of intravenous As2O3 in 8 relapsed acute promyelocytic leukemia (APL) patients were studied by Gas-phase chromotography. RESULTS: (1) After 2 hour intravenous drips of 10mg As2O3, drug plasma maximal concentration (Cpmax) was 0.94 +/- 0.37mg/L(x +/- s), time to peak concentration (Tp) was 4hrs, T1/2 alpha and T1/2beta were 0.89 +/- 0.29hrs and 12.13 +/- 3.31hrs, respectively, apparent volume of distribution (Vc) was 3.83 +/- 0.45L, system clearance (CLs) was 1.43 +/- 0.17L/h and area under curve (AUC) was 7.25 +/- 0.97mg x h/L. Importantly, the continuous administration of As2O3 did not alter the pharmacokinetic behaviors. (2) During As2O3 therapy, 24-hour arsenic content in urine accounted for 1%-8% of the total dose (10mg) per day. And it decreased gradually after drug withdrawal. (3) Arsenic contents in nail and hair were increased continuously during As2O3 therapy. The peak concentrations could be five to seven-fold higher than that pre-treatment. It also decreased gradually after drug with drawal. CONCLUSION: As2O3 is a relatively safe and effective drug in the treatment of APL patients, in spite of certain accumulation in some tissues.

Adolescent↗
PubMed1997

[Enrichment and determination of trace chlorobenzene compounds in water].

In this work, by using GDX-402 porous polymer beads as adsorbent and carbon disulfide as eluent, the conditions for enriching trace chlorobenzene compounds in water were investigated. Enriched eluate was directly injected into a column packed with 3.0% dihexyl sulfonic acid sodium/101 white support to be separated, and then detected by flame ionization detector under constant temperature. The method has been used successfully for the determination of trace of chlorobenzene compounds in water.

Chlorobenzenes↗
PubMed1997

[Clinical analysis of spontaneous perforation of abdominal viscera in patients with severe viral hepatitis].

Eight out of 246 patients with severe viral hepatitis were complicated with spontaneous abdominal viscera perforation. The eight patients all had serious digestive symptoms, orange green colour in skin, swollen abdomen with ascites, abdominal pain. All cases were diagnosed by liver function examination, colour ultrasonography, x-ray examination, abdominal puncture and one case by operation. Among these 8 cases, 3 cases had perfornation of stomach, 3 cases had perforation of gall bladder and 2 cases had perforation of small intestine. Though emergancy treatment had been applied, only one case was saved.

Adult↗
PubMed1996

Structure of the distal human gonadotropin releasing hormone (hGnrh) gene promoter and functional analysis in Gt1-7 neuronal cells.

To assess potential species-specific expression of gonadotropin releasing hormone (GnRH), the distal human (h) GnRH promoter was cloned, characterized and tested in gene transfer studies. The nucleotide sequence of approximately 3.8 kb of 5'-flanking region was determined. Homology to the rat (r) GnRH sequence was observed in the proximal promoter region between -551 h (-424 r) and the transcriptional start site and within multiple distal promoter regions. In contrast, there was little similarity in the sequences between -1131/-551 h and -1031/-424 r. A deletion panel of 5'-flanking hGnRH promoter constructs was made and tested in transient transfection assays in GnRH-producing mouse GT1-7 neuronal cells. The largest hGnRH promoter construct (-3832/+5 h) exhibited high levels of reporter activity, similar to that observed with the largest rGnRH construct (-3026/+116 r). However, in contrast to the rat gene, deletion of distal promoter sequences of the hGnRH promoter to -1971, -1131 or -551 did not result in a decrease in luciferase reporter activity. Further truncation to -350 resulted in a 3-fold decrease in luciferase activity. There was no preferential use of the putative upstream hGnRH start site in neuronal cells. DNase I protection assays showed unique protection patterns with nuclear extracts from GT1-7 and Gn10 neuronal cells and the hGnRH and rGnRH promoter fragments. These data suggest the presence of different cis-acting elements and transacting factors that mediate species-specific neuronal GnRH expression.

Animals↗
PubMed1996

New developments in flow injection separation and preconcentration techniques for electrothermal atomic absorption spectrometry.

Flow injection (FI) on-line separation and preconcentration systems for electrothermal atomic absorption spectrometry (ETAAS) are reviewed, highlighting the main developments in the field since 1990 and work achieved in the authors' laboratory. These include developments in on-line preconcentration systems based on column techniques, solvent extraction, coprecipitation and hydride sequestration. Advantages, limitations and potentials of the FI-ETAAS combination are discussed.

Journal Article↗
PubMed1996

Anesthetic and convulsant properties of aromatic compounds and cycloalkanes: implications for mechanisms of narcosis.

We examined the anesthetic and convulsant properties of 16 unfluorinated to completely fluorinated aromatic compounds, having six to nine carbon atoms (e.g., benzene to 1,3,5-tris(trifluoromethyl)benzene), and four cycloalkanes (cyclopentane to cyclooctane). Benzene, fluorobenzene, toluene, p-xylene, ethylbenzene, and cyclopentane caused excitation (twitching, jerking, and hyperactivity), and three aromatic compounds (perfluorotoluene, p-difluorotoluene and 1,3,5-tris(trifluoromethyl)benzene) and three cycloalkanes (cyclohexane, cycloheptane, and cyclooctane) produced convulsions. Cyclooctane and 1,3,5-tris(trifluoromethyl)benzene were nonanesthetics. Except for nonanesthetics and perfluorotoluene (too toxic to test for anesthetic potency), all compounds produced anesthesia or decreased the minimum alveolar anesthetic concentration of desflurane. Aromatic compounds were more potent and lipid-soluble than n-alkanes (data from previous report) and cycloalkanes. All three series increasingly disobeyed the Meyer-Overton hypothesis as molecular size increased. For a particular number of carbons (e.g., cyclohexane, n-hexane, and benzene), the deviation was cycloalkanes > or = normal alkanes > aromatic compounds. These results suggest that molecular shape (including "bulkiness") and size provide limited clues to the structure of the anesthetic site of action.

Anesthesia, Inhalation↗
PubMed1996

Occupational and Environmental Risk Factors for Asthma in Rural Communities in China.

Respiratory allergens such as dust, gases/fumes, and hay smoke, which are frequently present in agricultural settings, can cause or aggravate asthma. The purpose of this study was to examine the relationships between occupational and environmental exposures and asthma in Chinese rural communities. The study population consisted of 28,946 people 15 years old or older, living in rural areas of Anhui province, China. A modified Mandarin translation of the ATS-DLD questionnaire was administered by trained interviewers to request information about exposures to specific occupational/environmental agents and respiratory disorders. In Huaining, the prevalence of wheezing was 3.8% for men; 2.1% for women; the prevalence of asthma was 1.6% for men; 1.8% for women. In Zongyang, the prevalence of wheezing was 2.7% for men; 1.9% for women; the prevalence of asthma was 1.7% for men; 1.2% for women. With control for potential confounders such as gender, age, residential area, education level, and smoking status, the pooled adjusted odds ratios (ORs) of wheezing and asthma for the group exposed to wood/hay smoke were 1.36 (95% CI: 1.14-1.61) and 1.27 (95% CI: 1.02-1.58), respectively. For coal-stove users, the pooled adjusted ORs were 1.47 (95% CI: 1.09-1.98) for wheezing and 1.51 (95% CI: 1.05-2.17) for asthma. After stratification of the subjects by dust type, the estimated ORs for wheezing were 1.58 (95% CI: 1.02-2.44) among the group exposed to inorganic dust and 3.03 (95% CI: 1.25-7.33) among the group exposed to metal dust. Asthma was not shown to be significantly associated with any specific dust type. Findings of the present study are consistent with previously reported adverse respiratory health effects related to occupational/environmental exposures to wood/hay smoke and dust, and indicate the need for further occupational disease surveillance in rural communities.

Journal Article↗