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Biomedical subjects

H Min

Publications and source records attributed to H Min.

At least 37 records · Page 2Linked to original sources

[Studies on fermentation conditions of cytokinin produced by rhizobia strain 4012a].

The conditions of cytokinin fermentation of the rhizobia strain 4012a were detected by the ELISA. The results indicated that the optimal medium for cytokinin production by strain 4012a was composed of glucose 10 g/L, (NH4)2SO4 1.0, K2HPO4.3H2O 0.6, MgSO4.7H2O 0.1, CaCl2.2H2O 0.4, FeCl3.6H2O 0.04, Na2MoO4.2H2O 0.1 mg/L, calcium pantothenate 100 micrograms/L, adenine 200 mg/L. When strain 4012a was grown in 250 ml flask containing 50 ml of the medium on the rotary shaker (150 r/min) at 27 degrees C for 96 h, the yield of CTK 908 micrograms/L culture solution was obtained. It displayed bioactivity kinetin equivalents (KE) 1 mg/L medium with the radish cotyledon expansion test.

Culture Media↗

[A study on microbiological characteristics of upflow anaerobic filter].

This experiment was conducted to study the relationship between performance and bacterial population in upflow anaerobic filter by improved Hungate technique. The results obtained showed as follows: (1) There existed correlation closely between the bacterial population, COD and volatile fatty acids removal; (2) The bacterial population was affected to a small extent by the change of organic loading rate in short time and suspending performance; (3) Successful performance of the reactor depended on the microbes' composition and their coordinated metabolism.

Bacteria, Anaerobic↗

Serum cortisol levels in patients with uncomplicated and cerebral malaria.

Ten patients with uncomplicated malaria, ten with cerebral malaria and 37 controls (blood donors from blood bank) were included in the study. The serum cortisol levels of the patients were determined daily for 7 days while they were at the hospital. A radio-immunoassay method was used for quantitative measurement of cortisol in human serum. The mean serum cortisol level of patients with uncomplicated malaria was 528.2 +/- 123.9 nmol/l, with cerebral malaria was 516.0 +/- 80.5 nmol/l, and in controls was 393.8 +/- 141.0 nmol/l. There was a significant rise of serum cortisol levels in patients with malaria when compared to controls at the day of admission to hospital. There was no significant difference between uncomplicated malaria patients and those with cerebral malaria. There was also no significant difference between the different days of treatment up till day 7. We found no cortisol insufficiency in cases with falciparum malaria during acute and convalescent stages of illness.

Adolescent↗

p53 gene mutation in N-butyl-N-(4-hydroxybutyl)nitrosamine-induced urinary bladder tumors and N-methyl-N-nitrosourea-induced colon tumors of rats.

We analyzed p53 mutations in 17 N-butyl-N-(4-hydroxybutyl) nitrosamine-induced bladder transitional cell carcinomas (TCCs) with or without areas of squamous cell carcinoma (SCC) of Long-Evans Cinnamon (LEC) and F344 rats, and in 7 N-methyl-N-nitrosourea-induced colon adenocarcinomas of LEC rats by polymerase chain reaction-single strand conformation polymorphism analysis and DNA sequencing. Of these bladder tumors, one TCC with moderately differentiated SCC had a T to G transversion mutation at codon 141, leading to a Val to Gly amino acid change. No p53 mutation was found in colon adenocarcinomas. Thus a p53 gene mutation seems infrequent in these rat bladder and colon carcinogenesis models even in the late stage.

Animals↗

A new regulatory protein, KSRP, mediates exon inclusion through an intronic splicing enhancer.

We have purified and cloned a new splicing factor, KSRP. KSRP is a component of a multiprotein complex that binds specifically to an intronic splicing enhancer element downstream of the neuron-specific c-src N1 exon. This 75-kD protein induces the assembly of five other proteins, including the heterogeneous nuclear ribonucleoprotein F, onto the splicing enhancer. The sequence of the KSRP cDNA indicates that the protein contains four K homology RNA-binding domains and an unusual carboxy-terminal domain. KSRP is similar to two proteins, FUSE-binding protein and P-element somatic inhibitor. KSRP is expressed in both neural and non-neural cell lines, although it is present at higher levels in neural cells. Antibodies specific for KSRP inhibit the splicing of the N1 exon in vitro. Moreover, this inhibition of N1 splicing can be rescued by the addition of purified KSRP. KSRP is likely to regulate splicing from a number of intronic splicing enhancer sequences.

Amino Acid Sequence↗

Anti-sexual and anxiogenic behavioral consequences of corticotropin-releasing factor overexpression are centrally mediated.

Corticotropin-releasing factor (CRF) acts as a neurotransmitter in brain to promote behavioral responses such as flight and immobility, which have adaptive value in the context of exposure to environmental stressors. CRF also suppresses behavioral repertoires such as mating, which are incompatible with such threat-related coping responses. In this study, we employed transgenic (Tg) mice which overexpress CRF in brain and exhibit a constitutive and persistent phenotype of emotionality in order to determine the consequences of long-term CRF excess on indices of reproductive success, male sexual performance and female sexual receptivity. Sexual performance of CRF Tg males was relatively intact, whereas female receptivity was masked in CRF Tg mice by active rejection of sexually experienced male counterparts. This impairment in social interaction was only partially normalized by the serotonin antagonist, methysergide, which enhanced olfactory exploration of the still non-receptive CRF Tg females. Moreover, the anxiogenic-like character of CRF Tg mice is likely to be centrally mediated, since attenuation of hypercorticosteronemia by adrenalectomy did not alter either impaired sexual receptivity or fear-like behavior in an animal model of anxiety. Thus, overexpression of CRF in the brain results in a variety of adverse consequences including diminished social interactions.

Animals↗

[Effect of butachlor on CH4 emission and anaerobes in paddy soil].

Effects of butachlor on CH4 emission and the count of anaerobes in paddy soil or in the media were studied. The results obtained showed that CH4 emission and growth of methanogens would be greatly affected at field rates of butachlor within 2 weeks, but this adverse effects would disappear as time went on. CH4 emission and methanogenic activities would be retarded by butachlor in media for longer time. The amount of butachlor available to act upon anaerobes depended on application rate and method of application.

English Abstract↗

Low prevalence of immunogenetic markers of IDDM in adult Koreans with diabetes detected on OGTT.

In the Asian populations, it is not uncommon for adult patients with NIDDM to eventually lose beta-cell function and develop IDDM. Accepting that IDDM is an autoimmune disease, which occurs on a genetic background, it could by hypothesized that by measuring autoantibody prevalence and HLA DQ gene polymorphism, known important prediagnostic markers of IDDM, the prevalence of adult-onset IDDM in patients with previously undiagnosed NIDDM patients could be estimated. To do this, anti-GAD prevalence and HLA DQ A1 and DQ B1 polymorphisms after PCR amplification of genomic DNA were analyzed in 121 newly diagnosed diabetic patients of Yonchon cohort and compared to the results with those of 100 matched health control subjects. We also compared the results with those of other populations to assess the difference of genotype distribution. The overall prevalence of anti-GAD antibodies was 1.7% (2 of 121) in patients with previously undiagnosed NIDDM, whereas 1 of 100 controls had positive antibodies. Among those who were positive, their titer of antibodies to GAD were not high. No statistically significant differences in the distribution of either mean levels of anti-GAD or DQA1 and DQB1 alleles were found comparing NIDDM patients to controls. Interestingly, the frequency of DQB1*non-Asp-57 and DQA1*Arg-52 alleles in the Korean adult control population was similar to that of US Caucasians (DQB1*non-Asp-57: 0.431 vs. 0.475; DQA1*Arg-52: 0.492 vs. 0.463). The low prevalence of anti-GAD antibodies and HLA-DQA1 and DQB1 susceptibility alleles among recent-onset NIDDM patients, not different compared to controls suggests that diabetes in Korean adults is unlikely to have an autoimmune component to its pathogenesis.

Adult↗

Community-based epidemiologic study on atherosclerotic cardiovascular risk factors.

The present study was undertaken to determine the prevalence of hyperlipidemia and to find out the possible impact of serum lipid profiles on other cardiovascular risk factors in Yonchon County, Korea. Population-based cross-sectional study by random cluster sampling of registered residents over 30 years of age was performed. Out of the 3804 subjects scheduled for the survey, 2520 underwent the actual examination. The prevalence of hypercholesterolemia (serum cholesterol > or = 240 mg/dl) was only 1.2%, whereas that of hypertriglyceridemia (serum triglyceride > or = 250 mg/dl) was as high as 11.3%. The serum levels of cholesterol, triglyceride and HDL cholesterol correlated with anthropometric indices, body mass indices and waist hip ratios. The prevalences of diabetes and/or hypertension increased as either serum cholesterol or triglyceride level increased. In addition, the prevalence rates of obesity, impaired glucose tolerance, hypertriglyceridemia and hypercholesterolemia in its isolated form (free of the others) were much lower than overall prevalence indicating an existence of major overlap among these cardiovascular atherosclerotic risk factors in the form of multiple combinations. Central obesity was found to be an independent associated factor for the aggregation of the conditions related to the increase in cardiovascular risks. The prevalence of hypercholesterolemia in Yonchon County was substantially lower than that previously suggested, albeit that of hypertriglyceridemia was very high. We could also observe a varying degree of transition in cardiovascular risks related to insulin resistance from the rural to the urban area with rapid emergence of non-communicable diseases as a result of modernization.

Adult↗

The low prevalence of immunogenetic markers in Korean adult-onset IDDM patients.

OBJECTIVE: IDDM is an autoimmune disease that occurs among genetically susceptible individuals. In Asian populations, it is not uncommon for adult patients with NIDDM to eventually lose beta-cell function and develop IDDM. These individuals may be characterized by autoantibodies to GAD and high-risk HLA-DQ alleles, which are unlikely to be prevalent among patients with true NIDDM or in the general population. The objective of the present study was to evaluate and compare the prevalence of these immunogenetic markers in NIDDM patients and healthy nondiabetic individuals from Korea. RESEARCH DESIGN AND METHODS: The prevalences of anti-GAD antibodies and HLA-DQA1 and DQB1 alleles among 121 patients with newly diagnosed NIDDM identified from a population-based study in Yonchon, Korea, and 100 matched healthy control subjects were evaluated and compared. RESULTS: The overall prevalence of anti-GAD antibodies was 1.7% (2 of 121) in patients with previously undiagnosed NIDDM, whereas 1 of 100 control subjects had a positive test for antibodies. Among those who tested positive, titers of antibodies to GAD were not high. No statistically significant differences in the distributions of either mean levels of anti-GAD antibodies or DQA1 and DQB1 alleles were found comparing NIDDM patients with control subjects. Interestingly, the frequency of DQB1*non-Asp-57 and DQA1*Arg-52 alleles in the Korean adult control population was similar to that in the U.S. white population (DQB1*non-Asp-57: 0.431 vs. 0.475; DQA1*Arg-52: 0.492 vs. 0.463). CONCLUSIONS: The low prevalence of anti-GAD antibodies and HLA-DQA1 and DQB1 susceptibility alleles among recent-onset NIDDM patients, which was similar to observations in control subjects, suggests that diabetes in Korean adults is unlikely to have an autoimmune component to its pathogenesis.

Adult↗

The generally expressed hnRNP F is involved in a neural-specific pre-mRNA splicing event.

The proteins and RNA regulatory elements that control tissue-specific pre-mRNA splicing in mammalian cells are mostly unknown. In this study, a set of proteins is identified that binds to a splicing regulatory element downstream of the neuron specific c-src N1 exon. This complex of proteins bound specifically to a short RNA containing the regulatory sequence in neuronal extracts that splice the N1 exon. It was not seen in non-neuronal cell extracts that fail to splice this exon. UV-cross-linking experiments identified a neuron-specific 75-kD protein and several nontissue-specific proteins, including the 53-kD heterogeneous nuclear ribonucleoprotein F (hnRNP F), as components of this complex. Although present in both extracts, hnRNP F binds tightly to the RNA only in the neuronal extracts. A mutation in the regulatory RNA sequence, that inhibits N1 splicing in vivo, abolished formation of the neuron-specific complex and the binding of the neuron-specific 75-kD protein. Competition experiments in the two extracts show that the binding of the neuronal protein complex to the src pre-mRNA is required to activate N1 exon splicing in vitro. Antibody inhibition experiments indicate that the hnRNP F protein is a functional part of this complex. The assembly of regulatory complexes from both constitutive and specific proteins is likely to be a general feature of tissue-specific splicing regulation.

Animals↗

Prevalence of diabetes and IGT in Yonchon County, South Korea.

OBJECTIVE: To determine the prevalence of diabetes and impaired glucose tolerance (IGT) in Yonchon County of South Korea and to investigate their associated factors. RESEARCH DESIGN AND METHODS: We performed a population-based cross-sectional study with random cluster sampling of residents > or = 30 years of age. Among the 3,804 residents sampled, a total of 2,520 participants had a standard 75-g oral glucose tolerance test and answered a detailed questionnaire. We also collected standard anthropometric data. RESULTS: If the data for participants in the age range of 30-64 years were adjusted to the standard world population, the prevalence of diabetes was 7.2% and the prevalence of IGT was 8.9%. It was observed that the significant factors associated with diabetes were waist-to-hip circumference ratio, serum triglyceride levels, age, systolic blood pressure, family history of diabetes, and locality. CONCLUSIONS: The prevalence of diabetes in Yonchon County was substantially higher than was previously suggested. The risk of diabetes increased with the increased central obesity and metabolic disturbances associated with insulin resistance.

Adult↗

A new staging system for nasopharyngeal carcinoma in China.

PURPOSE: An accurate and rational nasopharyngeal carcinoma (NPC) stage based on images is proposed. METHODS AND MATERIALS: Four hundred and twenty-one cases of NPC, treated in the Cancer Hospital, Sun Yat-sen University of Medical Sciences (SUMS), with computed tomography scanning before initial radiotherapy, are analyzed. Important prognostic factors that form the basis of the new staging system are screened out by means of Cox model and clinical experiences. Survival curves of various kinds of T and N stages are compared by computer simulation. A new staging system is proposed by studying the traditional staging systems such as the AJC, UICC, Ho's and Changsha systems. RESULTS: According to the new staging criteria, the 5-year survival rates for Stages I-IV are 89.7%, 75.9%, 51.3%, and 22.2%, respectively. CONCLUSION: This new clinical staging for NPC based on a large amount of cases multivariate analysis is satisfactory and widely used in China.

Adult↗