Biomedical subjects

Y Jin

Publications and source records attributed to Y Jin.

At least 109 records · Page 6Linked to original sources

PubMed2001

Steroid 5alpha-reductases and 3alpha-hydroxysteroid dehydrogenases: key enzymes in androgen metabolism.

Androgen action in mammals can be regulated at the pre-receptor level by the intracellular formation and degradation of potent androgens, such as 5alpha-dihydrotestosterone (5alpha-DHT). In androgen target tissues (e.g. prostate), 5alpha-DHT is formed from circulating testosterone by the action of the type 2 steroid 5alpha-reductase (5alpha-R) and its action is terminated by the action of a reductive 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) which forms the weak androgen 3alpha-androstanediol. Oxidative 3alpha-HSD isoforms, however, can provide an alternative source of potent androgens by converting 3alpha-androstanediol to 5alpha-DHT. Working in concert, 5alpha-Rs and 3alpha-HSDs determine the amount and the type of androgen available for the androgen receptor and hence affect transcription of genes under androgen control. In peripheral tissues (e.g. liver), type 1 5alpha-R and reductive 3alpha-HSD isoforms work consecutively to eliminate androgens and protect against hormone excess. Thus, different 5alpha-R and 3alpha-HSD isoforms participate in distinct anabolic and catabolic processes and their important roles in androgen action render them drug targets for the treatment of androgen-dependent diseases.

3-Hydroxysteroid Dehydrogenases↗

PubMed2001

Are there histopathologic characteristics particular to fulminant hepatic failure caused by human herpesvirus-6 infection? A case report and discussion.

An 8-month-old boy was admitted to a neighboring hospital for severe liver dysfunction and drowsiness 4 days after a diagnosis of exanthem subitum. A diagnosis of fulminant hepatic failure was made, and liver biopsy was performed during the acute stage. The presence of human herpesvirus-6 variant B (HHV-6B) DNA was shown in liver tissue by polymerase chain reaction (PCR) and in the endothelium of the portal vein by in situ hybridization (ISH). Histologic examination showed microvesicular steatosis resembling that of Reye's syndrome, even though aspirin had not been prescribed. We considered HHV-6 to be the causative agent in this case and report what is perhaps the first precise histologic description of fulminant hepatic failure caused by HHV-6.

DNA Primers↗

PubMed2001

Theory and laboratory study of a tall passive chamber for measuring gas fluxes at soil surface.

A tall passive flux chamber with a height significantly greater than its horizontal dimensions is proposed for measuring fluxes of volatile organic compounds (VOCs) at the soil surface. The main feature of this tall chamber is the presence of a vertical concentration gradient of the target gas in the chamber. The emission and transport behavior of the target gas in the soil-chamber system are analyzed using the diffusion theory. A mathematical model is developed to estimate the flux from the soil into the tall chamber, providing the target gas establishes a detectable vertical concentration gradient in the chamber. To obtain the data required for calculating flux, only two gas concentrations (C1 and C2) at two heights (h1 and h2) within the chamber need to be measured at the end of a short chamber placement time (tp). To evaluate the applicability of the tall chamber for measuring flux, several laboratory tests have been conducted, using CH2Cl2 and CH3Br as the target gases. The results indicate that the proposed tall chamber has promising potential as a method for measuring fluxes of VOCs at the soil surface.

Air Pollutants↗

PubMed2001

Clozapine enhances neurocognition and clinical symptomatology more than standard neuroleptics.

Neurocognition and clinical symptomatology were evaluated in 27 patients with schizophrenia during a double-blind, placebo-controlled, cross-over study involving clozapine, an atypical antipsychotic agent, and haloperidol, a conventional neuroleptic. Patients were assessed 5 to 6 weeks after initiation of each phase. Clinical symptomatology, based on Brief Psychiatric Rating Scale and Scale for the Assessment of Negative Symptoms ratings, markedly improved after treatment with both haloperidol and clozapine. The beneficial effects of clozapine were statistically significantly greater than the effects from the haloperidol treatment. Regarding neurocognition, both agents proved efficacious in improving performance on nearly all measures compared with placebo. In addition, as compared with haloperidol, clozapine significantly improved performance on Trails B, Verbal Fluency, and measures of delayed verbal memory, and it tended to increase performance on most measures. Additional analyses indicated that the improvement on neurocognitive measures was not because of symptom amelioration; rather, neurocognitive deficits seem to be an intrinsic enduring feature of schizophrenia. The superiority of clozapine over haloperidol may be related to clozapine's unique psychopharmacologic profile.

Adult↗

PubMed2001

Neural route of cerebral Listeria monocytogenes murine infection: role of immune response mechanisms in controlling bacterial neuroinvasion.

The pathologic features of cerebral Listeria monocytogenes infection strongly suggest that besides hematogenous spread, bacteria might also spread via a neural route. We propose that after snout infection of recombination activating gene 1 (RAG-1)-deficient mice, L. monocytogenes spreads to the brain via a neural route. The neural route of invasion is suggested by (i) the immunostaining of L. monocytogenes in the trigeminal ganglia (TG) and brain stem but not in other areas of the brain; (ii) the kinetics of bacterial loads in snout, TG, and brain; and (iii) the increased resistance of mice infected with a plcB bacterial mutant (unable to spread from cell to cell). Gamma interferon (IFN-gamma) plays a protective role in neuroinvasion; inducible nitric oxide synthase (iNOS) accounts only partially for the protection, as shown by a comparison of the susceptibilities of IFN-gamma receptor (IFN-gamma R)-deficient, iNOS-deficient, and wild-type mice to snout infection with L. monocytogenes. The dramatically enhanced susceptibility of RAG-1-deficient, IFN-gamma R gene-deficient mice indicated the overall importance of innate immune cells in the release of protective levels of IFN-gamma. The source of IFN-gamma appeared to be NK cells, as shown by use of RAG-1-deficient, gamma-chain receptor gene-deficient mice; NK cells played a relevant protective role in neuroinvasion through a perforin-independent mechanism. In vitro evidence indicated that IFN-gamma can directly induce bacteriostatic mechanisms in neural tissue.

Animals↗

PubMed2001

Antisense GLUT-1 protects mesangial cells from glucose induction of GLUT-1 and fibronectin expression.

A stable clone of rat mesangial cells expressing antisense GLUT-1 (i.e., MCGT1AS cells) was developed to protect them from high glucose exposure. GLUT-1 protein was reduced 50%, and the 2-deoxy-[(3)H]glucose uptake rate was reduced 33% in MCGT1AS. MCLacZ control cells and MCGT1 GLUT-1-overexpressing cells were used for comparisons. In MCLacZ, 20 mM D-glucose increased GLUT-1 transcription 90% vs. no increase in MCGT1AS. Glucose (8 mM) and 12 mM xylitol [a hexose monophosphate (HMP) shunt substrate] did not stimulate GLUT-1 transcription. An 87% replacement of the standard 8 mM D-glucose with 3-O-methylglucose reduced GLUT-1 transcription 80%. D-Glucose (20 mM) increased fibronectin mRNA and protein by 47 and 100%, respectively, in MCLacZ vs. no increases in MCGT1AS. Fibronectin synthesis was elevated 48% in MCGT1 and reduced 44% in MCGT1AS. We conclude that 1) transcription of GLUT-1 in response to D-glucose depends on glucose metabolism, although not through the HMP shunt, and 2) antisense GLUT-1 treatment of mesangial cells blocks D-glucose-induced GLUT-1 and fibronectin expression, thereby demonstrating a protective effect that could be beneficial in the setting of diabetes.

ATP-Binding Cassette Transporters↗

PubMed2001

A social problem index for Canada.

OBJECTIVE: To construct an index that represents the general level of social problems among Canadian provinces and territories. METHOD: Factor weights were used to combine provincial and territorial rates for homicide, attempted murder, assault, sexual assault, robbery, divorce, suicide, and alcoholism into a single Social Problem Index. RESULTS: The resulting index demonstrated strong positive intercorrelations among its factors across provinces. That is, provinces that showed high rates on one factor tended to show high rates on the others as well. The validity of the Social Problem Index is demonstrated by its positive correlation with an independent measure of the likelihood of having experienced personal trauma. CONCLUSIONS: The robust nature and apparent validity of the Social Problem Index suggest that it can be well used for needs assessments and theoretical studies and as a feedback mechanism to national, provincial, and community leaders on the social problem status of their particular jurisdictions.

Canada↗

PubMed2001

Association of airway responsiveness with asthma and persistent wheeze in a Chinese population.

STUDY OBJECTIVES: Data from a cross-sectional study were analyzed to examine the association of increased airway responsiveness with physician-diagnosed asthma and persistent wheeze. DESIGN: Two methods for calculating the provocative dose that decreases the airflow rate by 20% (PD(20)) were used as indexes for increased airway responsiveness: (1) a 20% drop in FEV(1) calculated from baseline FEV(1) (PD(20)b), and (2) a 20% drop in FEV(1) from FEV(1) measurements after inhalation of saline solution (PD(20)s). Both PD(20)b and PD(20)s were measured through induction by varying doses of methacholine. SETTING: Anqing, Anhui Province, China. PARTICIPANTS: Study subjects were 8 to 74 years of age and were classified into four groups: children (< 15 years old), young adults (15 to 29 years old), adults (30 to 44 years old), and older adults (> or 5 years old). INTERVENTIONS: The differences in estimated odds ratios of airway hyperresponsiveness with asthma and wheeze, sensitivity and specificity, and coefficients of variation were compared between PD(20)b and PD(20)s. The sample for analysis consisted of 10,284 subjects from 2,663 nuclear families with complete data on wheeze, asthma, and major potential confounding factors. MEASUREMENTS AND RESULTS: The prevalence of asthma in this sample was lowest in subjects with no demonstrable PD(20) and had a reverse dose-response relationship with PD(20) across all age groups. Using the receiver operating characteristic, the sensitivity and specificity of the PD(20)s or PD(20)b were found to be almost identical. A similar trend was found for persistent wheeze, although the estimated odds ratios for persistent wheeze appeared slightly smaller than those for physician-diagnosed asthma. CONCLUSIONS: This study demonstrates a dose-response relationship between increased airway responsiveness and asthma and wheeze in this Chinese population. PD(20)s or PD(20)b yielded virtually indistinguishable results, which indicated that either of the two tests could serve as an index of airway hyperresponsiveness.

Adolescent↗

PubMed2001

Transcriptional mRNA of BMP-2, 3, 4 and 5 in trigeminal nerve, benign and malignant peripheral nerve sheath tumors.

The aim of our study was to document whether relationships existed among bone morphogenetic proteins (BMPs), peripheral nerve and neoplastic lesions of nerve sheath tumors. The mRNA transcriptions of BMP-2, 3, 4 and 5 in 10 cases of schwannoma, three cases of malignant schwannoma and two cases of trigeminal neuralgia were detected using an in situ hybridization technique. Our results demonstrated that the myelin sheaths of Schwann cell from the peripheral neuroectomy of trigeminal neuralgia positively expressed mRNA of BMP-2, 3, 4, and 5. The most interesting finding was that the nerve fibers of trigeminal nerve showed only BMP-2 positive staining. All of the neoplastic lesions of nerve sheath showed a consistent but variant expression of BMP-2, 3, 4, and 5. The expression signals of BMP-2, 3, 5 mRNA in malignant schwannoma were relatively lower than in benign lesions except for the expression of BMP-4 mRNA. Our results indicated that selected members of BMPs were expressed in the peripheral nerves that might contribute to the health maintenance, proliferation, regeneration and neoplastic transformation of the peripheral nerve system. Furthermore, the effects of BMP-2, 3, 4 and 5 on peripheral nervous system during neoplastic transformation might be widespread, diverse and antagonistic.

Adult↗

PubMed2001

Caspase-3 apoptotic signaling following injury to the central nervous system.

Apoptotic cell death is a fundamental and highly regulated biological process in which a cell is instructed to participate actively in its own demise. This process of cellular suicide is activated by developmental and environmental cues and normally plays an essential role in eliminating superfluous, damaged, and senescent cells of many tissue types. In recent years, a number of experimental studies have provided evidence of widespread neuronal and glial apoptosis following injury to the central nervous system (CNS). These studies indicate that injury-induced apoptosis can be detected from hours to days following injury and may contribute to neurological dysfunction. Given these findings, understanding the biochemical signaling events controlling apoptosis is a first step towards developing therapeutic agents which would target this cell death process. This review will focus on the molecular cell death pathways responsible for generating the apoptotic phenotype, summarize what is currently known about apoptotic signals activated in the injured CNS, and what potential strategies might be pursued to reduce this cell death process as a means to promote functional recovery.

Animals↗

PubMed2001

Alteration of apoptosis in cleft palate formation and ectomesenchymal stem cells influenced by retinoic acid.

It has been shown that apoptosis is involved in normal embryonic development. The aim of the present study was to elucidate the role and alteration of apoptosis in the pathogenesis of cleft palate induced by retinoic acid (RA) and the ectomesenchymal stem (EMS) cells influenced by RA. RA was administered by gavage to pregnant C57BL/6N strain mice in the experimental group, and the control group received oil alone. Pregnant mice were killed at set periods of time thereafter and histologically analyzed. EMS cells explanted from the palatal shelves of embryonic mice were cultured and characterized by immunohistochemistry, growth curves and population-doubling time. The alterations of apoptosis of EMS cells and developing palatal shelves influenced by RA were evaluated by the terminal deoxynucleotidyl transferase-mediated UTP-biotin nick end-labeling (TUNEL) method. RA-treated mice showed formation of cleft palates resulted from the small size of the palatal shelves and their failure to lift. TUNEL staining showed that the number of apoptotic mesenchymal cells in palatal shelves in the RA-treated mice was increased significantly when compared with the control group. The primary culture of EMS cells proceeded successfully. The population-doubling time of RA-treated cells was much longer compared with non-treated EMS cells. RA also dramatically increased the number of apoptotic cells in EMS cells in vitro. We concluded that EMS cells are the crucial cells in palate development. RA could inhibit the proliferation and induced the apoptosis of EMS cells. The inhibition of growth and excess apoptosis of EMS cells may contribute to the formation of cleft palate and other orofacial congenital malformations.

Animals↗

PubMed2001

Apoptotic activity of novel bile acid derivatives in human leukemic T cells through the activation of caspases.

The therapeutic efficacies of bile acids, such as ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA), have been widely demonstrated in various liver diseases, suggesting that they might protect hepatocytes against common mechanisms of liver damage. Although they have been shown to prevent apoptotic cell death in certain cell lines, we have previously reported that a novel derivative (HS-1030) of UDCA significantly inhibited cell growth and induced apoptosis in cancer cells. To develop more effective agents, we synthesized several derivatives, named HS-1183, HS-1199 and HS-1200, based on the structure of UDCA and CDCA, and investigated them for anti-proliferative activity in Jurkat cells, a human leukemic T cell line. Whereas UDCA and CDCA had no significant effects on the growth of Jurkat cells in the concentration range tested, both HS-1199 and HS-1200 completely inhibited the cell proliferation, and HS-1183 showed only a weak inhibitory activity. Furthermore, chromatin condensation, DNA ladder formation and proteolytic cleavage of poly(ADP-ribose) polymerase (PARP) were observed after treatment of novel bile acids, indicating the occurrence of apoptotic cell death, which was associated with down-regulation of caspase-3 and -8. The apoptotic manifestations such as PARP cleavage and DNA fragmentation were abolished in the presence of the tripeptide caspase inhibitor zVAD-fmk or the specific caspase-3 inhibitor DEVD-fmk. Our data thus demonstrate that novel bile acid derivatives-induced apoptosis of leukemic T cells is dependent on caspase activation.

Apoptosis↗

PubMed2001

Characterization of chromosome aberrations in salivary gland tumors by FISH, including multicolor COBRA-FISH.

Fluorescence in situ hybridization (FISH), including COBRA-FISH, was used to characterize 11 salivary gland tumors that had been investigated by banding analysis. Five cases were pleomorphic adenoma (PA), three were adenoid cystic carcinoma, and one case each was mucoepidermoid carcinoma, carcinoma ex-pleomorphic adenoma (CaPA), and adenocarcinoma. All 11 cases were selected on the basis that they had shown rearrangement of 6q or 9p or had unresolved aberrations after karyotyping. The COBRA-FISH and FISH analyses led to a revised karyotype in all informative cases and made it possible to clarify almost all chromosomal rearrangements occurring in the tumors. Of particular note were the confirmation of the existence of 6q deletions, a common change in salivary gland carcinomas, and the demonstration that a seemingly balanced t(6;9) resulted in del(6q). Other rearrangements that were revealed by FISH included amplification of 12q sequences (MDM2 and CDK4) in one PA. We also investigated the status of the PLAG1 gene in four cases (one PA, one CaPA, one adenoid cystic carcinoma, and one mucoepidermoid carcinoma) with 8q12 rearrangements. Only in the former two cases were the FISH results compatible with intragenic rearrangements. Overall, the results of the study show that, even with good banding quality and in karyotypes of modest complexity, much new information will be gained by supplementing the banding analysis with a multicolor FISH approach, such as COBRA-FISH.

Adult↗

PubMed2001

[Analysis on associations of cytochrome P450 1A1-Hinc II and glutathion S-transferase-theta with primary dysmenorrhea].

OBJECTIVE: To investigate the genetic susceptibility to primary dysmenorrhea. METHODS: Data of 499 female workers in a textile mill were collected. The associations of cytochrome P450 1A1-Hinc II(CYP 1A1-Hinc II) and glutathion S-transferase-theta(GSTT1) polymorphisms with heavy primary dysmenorrhea were evaluated by Logistic regression, with adjustment for potential confounders. RESULTS: The result showed variant of CYP1A1- Hinc II genotypes slightly reduced the risk of primary dysmenorrhea, but its OR value was not statistically significant (CYP1A1-Hinc II:OR=0.64, 95% CI 0.35-1.17). The GSTT1 genotype variant increased the risk of primary dysmenorrhea (GSTT1:OR=1.83, 95% CI 1.04-3.21). After potential confounders were adjusted, the data showed that CYP1A1-Hinc II variant had the trend of decreasing the risk of dysmenorrhea (CYP1A1-Hinc II:OR=0.58, 95% CI 0.31-1.08), but its decreasing scope was still not statistically significant. The GSTT1 variant genotypes showed a significantly increased risk of dysmenorrhea (GSTT1:OR=2.01, 95% CI 1.12-3.62). CONCLUSION: The results suggested that GSTT1 polymorphism be associated with heavy primary dysmenorrhea.

Adult↗

PubMed2001

[Expression of tumor suppressor genes p16, p21 and p53 in a pair of lung adenocarcinoma cell lines with different metastasis potentials: Anip973 and AGZY83-a].

OBJECTIVE: In order to investigate the suppression effect of tumor suppressor genes in lung adenocarcinoma. METHODS: p16 and p21 expression vectors were transfected into a pair of lung adenocarcinoma cell lines with different metastasis potentials: Anip973(high metastasis potential)and AGZY83-a (low metastasis potential). In the mean time, AGZY83-a, Anip973, AGZY83-ap16 and Anip973p16 were infected with recombinant adenovirus encoding wild- type p53 gene. The suppression effects of these genes were evaluated by cell growth curve, MTT, cloning efficiency assay, flow cytometric analysis and TUNEL technique. RESULTS: Overexpression of p16 gene in Anip973 and AGZY83-a could only lengthen the G(1) phase while increased expression of p21 in both of the cell lines was associated with significant lengthening of G(1) phase, decreased proliferation potential and decreased cloning efficiency. High efficient expression of wild-type p53 gene in AGZY83-a, Anip973, Anip973p16 and AGZY83-ap16 inhibited the growth of these four kinds of lung cancer cells and killed the cells in the end. Apoptosis was detected in all the four kinds of cells. The suppression effect of p53 gene was higher in Anip973 and Anip973p16 than in AGZY83-a and AGZY83-ap16 while co-expression of p53 and p16 in this pair of cell lines inhibited the cells more efficiently as compared with the expression of p53 gene. CONCLUSION: Increased expression of p21 gene suppressed the lung adenocarcinoma cells by G(1) arrest and the co-transfection of tumor suppressor genes p16 and p53 into the lung adenocarcinoma cell line proved more effective in lung cancer gene therapy.

Adenocarcinoma↗

PubMed2001

Transcriptional mRNA of bone morphogenetic proteins 2, 3, 4, and 5 in trigeminal nerve, benign and malignant peripheral nerve sheath tumors.

Bone morphogenetic proteins (BMPs) have been shown to play an important role in cell growth and differentiation. BMPs, a rapidly expanding family closely related to transforming growth factor-beta (TGF-beta) superfamily, have been proven recently to possess a regulatory role and neurotrophic capacity in neurogenesis. The aim of the present study is to reveal the relationship among BMPs, peripheral nerve and neoplastic lesions of nerve sheath tumors. The mRNA transcriptions of BMP 2, 3, 4 and 5 in 12 cases of schwannoma, four cases of malignant schwannoma and three cases of trigeminal neuralgia were detected using an in situ hybridization technique. Our results demonstrated that the myelin sheaths of schwann cell from the peripheral neuroectomy of trigeminal neuralgia were positively expressing mRNA of BMP-2, 3, 4 and 5. However, the nerve fibers of trigeminal nerve showed only BMP-2 positive staining. All of the neoplastic lesions of nerve sheath showed a consistent but variant expression of BMP-2, 3, 4, and 5. Except for the BMP-4 mRNA, the expression signals of BMP-2, 3 and 5 mRNA in malignant schwannoma were relatively lower than in benign lesions. On the basis of the findings, we concluded that selected members of BMPs existed in the peripheral nerves and might contribute to the health maintenance, proliferation, regeneration and neoplastic transformation of the peripheral nerve system. Moreover, the effects of BMP-2, 3, 4 and 5 on peripheral nerve system and its neoplastic transformation might be widespread, diverse and antagonistic.

Adult↗

PubMed2001

[A study of association between atherothrombotic brain infarction and HLA-DQA1 peptide binding motifs].

OBJECTIVE: To analyze the hereditary susceptibility for HLA-DQA1 alleles according to trait of multiple genes leading to disease in atherothrombotic brain infarction (ABI). METHODS: HLA-DQA1 alleles in ABI patients (n=81) and healthy controls (n=99) were detected by PCR-SSP techniques. RESULTS: (1)The frequency of HLA-DQA1*0301 was significantly higher in ABI patients. (2)The frequency of HLA-DQA1*0301 was significantly higher in patients with family history of essential hypertension (EH). (3)The frequency of HLA-DQA1*0103 was significantly lower in ABI patients. CONCLUSION: HLA-DQA1*0301 allele might be a correlative gene with hereditary susceptibility of ABI and HLA-DQA1*0301 allele might be a correlative gene in ABI patients with the family history of essential hypertension, whereas HLA-DQA1*0103 allele might be a protective gene in the patients with ABI.

Aged↗

PubMed2001

[Preparation and identification of activity of antiplatelet-derived growth factor receptor beta subunit hammerhead ribozyme in vitro].

OBJECTIVE: To study the preparation and cleavage activity of ribozyme directed against platelet-derived growth factor (PDGF) receptor beta subunit gene transcript in vitro. METHODS: PDGF receptor B subunit gene fragments were cloned into T-vector under the control of T7 promotor. 32P-labeled PDGF receptor beta subunit transcripts as target-RNAs were transcribed in vitro and purified by PAGE. Ribozyme gene designed by computer targeting the extracellular domain was cloned into vector P1.5 between 5'-cis ribozyme and 3'-cis ribozyme. 32P-labeled ribozyme transcripts was gel-purified, incubated with target-RNAs at different conditions and autoradiographed after denaturing gel-electrophoresis. RESULTS: The preparation of ribozyme was correct. It was active at 37 degrees C. The optimal temperature was 50 degrees C, Km=13,20 nm, Kcat=0.28 min-1. The cleavage efficiency was up to 78.3%. CONCLUSIONS: Ribozyme prepared in vitro possesses specific catalytic activity.

Animals↗