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Biomedical subjects

T Huang

Publications and source records attributed to T Huang.

At least 109 records · Page 6Linked to original sources
PubMed1997

[Alternative splicing of the FMR1 gene in human fetal tissues].

OBJECTIVE: To gain more insight into biological role of the alternative splicing of the FMR1 gene, isoforms of the FMR1 mRNA from human fetal heart, spleen, liver and kidney were analyzed. METHODS: RNAs were isolated from the tissues of an abortion fetus (approximately 6 months postconception). Alternative splicing patterns of the FMR1 mRNA were analyzed by RT-PCR and cloning strategy. RESULTS: One isoform of the FMR1 mRNA was found to be dominant in all of the four tissues. The major isoform was as same as the dominant one in the fetal cortex but was different from the major isoform in adult brain. The difference between the major isoforms in the fetal tissues and adult brain was the splicing out or retaining the peptide encoded by exon 12 and exon 17. CONCLUSION: This result suggested a developmental switch of alternative splicing of the FMR1 gene. The difference between the major isoforms in the fetal tissues and adult brain suggested the two peptides may have special roles in related developmental stages.

Alternative Splicing↗
PubMed1997

[Effect of light colours and illumination intensity on the sexual behaviour of Hepialus gonggaensis Fu et Huang].

The sexual behaviour of Hepialus gonggaensis has close relations with ecological environment and varies with its ecotypes. The more intense the illumination, the faster the sexual drive of Hepialus gonggaensis begins and the longer its sexual intercourse continues, light colours have a bearing on its sexual intercourse time. This study has provided an evidence for the artificial cultivation of Hepialus gonggaensis.

Animals↗
PubMed1997

[Diplopia after intraocular lens implantation].

PURPOSE: Seven patients with diplopia after intraocular lens implantation were reported. Possible causes and prevention of diplopia were investigated preliminarily. METHODS: Sixty successive cases, who had accepted uniocular cataract extraction and intraocular lens implantation, were followed-up. The kinds of diplopia, position of eyes, the movements of eyes, refrective state, pupil, fundus of eyes and the states of IOL were examined in all diplopia cases. RESULTS: The incidence of diplopia in our cases was 11.67%. There was a close relationship between postoperative diplopia and preexistent strabismus, fusion disruption, myotoxic effects of local anesthetics, decentration of intraocular lens, macular disease and in identical opacity of posterior capsule. CONCLUSION: Diplopia is a important complication after cataract extraction and intraocular lens implantation. Usually, it is difficult to deal with. It is helpful for decreasing diplopia to take corresponding methods according to possible causes.

Adult↗
PubMed1997

Clinical and economic impact of incidental thyroid lesions found with CT and MR.

PURPOSE: To estimate the prevalence and the clinical and economic consequences of management strategies for thyroid lesions detected incidentally on cross-sectional imaging of the head and neck. METHODS: Two hundred consecutive CT scans and 200 consecutive MR images of the neck performed over a 1-year period in patients being examined for other purposes were reviewed retrospectively to determine the prevalence of unexpected thyroid lesions. After excluding patients with prior thyroidectomies, known thyroid disease, and inadequate examinations, 231 imaging studies were analyzed. RESULTS: Incidental thyroid lesions were originally reported in 14 (6%) of the 231 patients, but an additional 22 (9.5%) were found on retrospective review for a total of nearly 16% (36 of 231). Six of the 36 patients received further workup, consisting of nuclear medicine scintigraphy (n = 3), sonography (n = 3), thyroid function tests (n = 5), fine-needle aspiration (n = 4), and thyroid lobectomy (n = 1). Final diagnoses, obtained in four of the six patients, included three multinodular goiters and one follicular adenoma. Two patients, one with nondiagnostic findings at fine-needle aspiration and a second with normal thyroid function test results, are being followed up. The mean cost of the workup and treatment per examined patient was $1158. CONCLUSION: Incidental thyroid lesions are frequently present and often overlooked on cross-sectional images of the neck in patients being examined for other reasons. The cost of pursuing a workup of these lesions and their high prevalence in the population raise questions regarding appropriate management strategies.

Adenoma↗
PubMed1997

[Chromosomal aberrations induced in human spermatozoa by mitomycin C].

Human spermatozoa were exposed to Mitomycin C (MM() at the concentrations of 7.5, 15, 3O micrograms/ml for 1 hour respectively before interspecific in vitro fertilization with zona-free hamster ova. The first cleavage metaphases was analyzed to investigate MMC-induced effects on human spermatozoa. The results showed a distinct dose-response relationship in the induction of chromosomal aberrations. The chromatid aberrations were the predominant types in MMC-induced changes. Some chromosome-type aberrations were also observed. This suggested that the induced effects of MMC on human spermatozoa were some different from that of ultraviolet light-like clastogens on somatic cells. 36.89% of MMC-induced aberrations were rejoining-type. This indicated that the DNA repair systems present in golden hamster oocytes were effective in repairing MMC-induced DNA lesions in human spermatozoa.

Animals↗
PubMed1997

[An experimental study of bioactive glass ceramics as orbital implants].

One eyeball of experimental rabbits was enucleated in routine procedure, and then implanted the biocative glass ceramic (BGC). No rejection was observed during the postoperation period. After three months of implantation, they were examined with ultrasound, and a venous-flow-like spectra was detected in the ceramic implant. After six months of implantation, the implans were examined histologically; the ingrowth fibrovascular tissue filled the 90% gaps of the implant. The results suggest that the bioactive glass ceramic implants made in China possess acceptable histocompatibility.

Animals↗
PubMed1996

Properties of tetrahydropteroylpentaglutamate bound to 10-formyltetrahydrofolate dehydrogenase.

A new rapid procedure for purifying 10-formyltetrahydrofolate dehydrogenase results in 90 mg of pure enzyme from two rabbit livers. This abundant liver enzyme is known to bind its product tetrahydropteroylpentaglutamate (H4PteGlu5) so tightly that it does not dissociate during size exclusion chromatography. 10-Formyltetrahydrofolate dehydrogenase is also known to exhibit strong product inhibition by H4PteGlu5. There is a several-fold excess of 10-formyltetrahydrofolate dehydrogenase subunits in liver relative to the concentration of H4PteGlun, suggesting that in vivo this enzyme may bind significant amounts of this coenzyme in a nearly irreversible enzyme. H4PteGlu5 complex. How this tightly bound H4PteGlun is transferred to the other two enzymes in the cytosol, serine hydroxymethyltransferase and C1-tetrahydrofolate synthase, which use H4PteGlu5 as a substrate, is the subject of this investigation. Analysis of the product inhibition curve for 10-formyltetrahydrofolate dehydrogenase shows that H4-PteGlu5 has a dissociation constant near 15 nM which is 60-fold lower than the Ks for 10-formyl-H4PteGlu5. Fluorescence titration studies also yield a Kd of about 20 nM for H4PteGlu5. Coupling the 10-formyltetrahydrofolate dehydrogenase reaction to an excess of either serine hydroxymethyltransferase or C1-tetrahydrofolate synthase not only abolishes product inhibition but also increases the initial rate of its activity by about 2-fold. Passage of a reaction mixture of 10-formyltetrahydrofolate dehydrogenase down a size exclusion column results in enzyme with 1 equiv of H4PteGlu5 bound per subunit. However, addition of either serine hydroxymethyltransferase or C1-tetrahydrofolate synthase results in a rapid transfer of this bound folate to these enzymes. Evidence is also presented that the tightly bound folate is in equilibrium with solvent H4PteGlu5.

Aminohydrolases↗
PubMed1996

Cytokine phenotype of human autoreactive T cell clones specific for the immunodominant myelin basic protein peptide (83-99).

Experimental allergic encephalomyelitis (EAE), an animal model resembling multiple sclerosis (MS), is mediated by myelin antigen-specific CD4+ T cells secreting cytokines such as interferon-gamma (IFN-gamma), tumor necrosis factor-beta (TNF-beta), and the proinflammatory cytokine TNF-alpha-all associated with the T-helper-1 (Th1) T cell subset. Based on numerous similarities between MS and EAE, it has been postulated that Th1-like T cells are involved in the pathogenesis of MS. Production of proinflammatory cytokines such as IFN-gamma and, in particular, TNF-alpha/beta by autoreactive T cells is considered crucial for the initiation and amplification of inflammatory brain lesions and possibly also for direct myelin damage. In contrast, regulatory cytokines such as interleukin-4 (IL-4), IL-10, and IL-13, which are associated with the Th2-like phenotype, may play a role in the resolution of relapses. Although the human T cell response to myelin basic protein (MBP) is well characterized in terms of antigen specificity, HLA restriction, and T cell-receptor (TCR) usage, little is known about the cytokine pattern of these autoreactive T cells. To gain such information, conditions for studying cytokine secretion by human autoreactive T cell clones (TCC) were established. The cytokine secretion profile of human autoreactive CD4+ TCC, specific for myelin basic protein peptide (83-89) [MBP(83-99)], a candidate autoantigen in MS, was investigated. Our results show that TCC cytokine production in long-term culture was stable. In addition, the correlation of various cytokines within specific TCC revealed differences compared to murine T cells. The comparison of 30 human MBP (83-99)-specific TCC demonstrated heterogeneity in cytokine secretion, with a continuum between Th1- and Th2-like cells rather than distinct Th1 or Th2 subsets. These data are important for further investigation of the potential role of cytokines in the inflammatory process of MS, and provide a powerful tool to investigate therapeutic interventions with respect to their influence on cytokine secretion of autoreactive T cells.

Amino Acid Sequence↗
PubMed1996

Alternative splicing of the FMR1 gene in human fetal brain neurons.

The alternative splicing expression of the FMR1 gene was reported in several human and mouse tissues. Five regions of FMR1 gene can be alternatively spliced, but the combination of them has not been investigated fully. We reported here the analysis of alternative splicing pattern of the FMR1 gene in cultured fetal human neurons, using a RT-PCR and cloning strategy. Eleven splicing types were cloned and different isoforms were not equally represented. The dominant isoform represents nearly 40%, and the other isoforms were relatively rare. One isoform has a different carboxylterminus. Most of the alternative spliced regions appear hydrophilic; thus, they may locate on the surface of the FMR1 protein.

Alternative Splicing↗
PubMed1996

Percutaneous balloon valvuloplasty for pulmonic stenosis in adolescents and adults.

BACKGROUND: Percutaneous balloon valvuloplasty has been the accepted first-line treatment for congenital pulmonic stenosis in children. Its efficacy in adolescents and adults is less well defined. METHODS: Between December 1985 and July 1995 we performed percutaneous pulmonic valvuloplasty with a single Inoue balloon catheter in 53 adolescent or adult patients 13 to 55 years of age (mean [+/- SD], 26 +/- 11). Follow-up studies were performed 0.2 to 9.8 years after the procedure (mean, 6.9 +/- 3.1) by Doppler echocardiography (in all the patients) and by cardiac catheterization and angiography (in nine patients). RESULTS: After balloon valvuloplasty, the systolic pressure gradient across the pulmonic valve decreased from 91 +/- 46 mm Hg to 38 +/- 32 mm Hg (P < 0.001), and the diameter of the pulmonic-valve orifice increased from 8.9 +/- 3.6 mm to 17.4 +/- 4.6 mm (P < 0.001). In the nine patients catheterized at follow-up, the systolic gradient decreased from 107 +/- 48 mm Hg before valvuloplasty to 50 +/- 29 mm Hg after valvuloplasty and to 30 +/- 16 mm Hg at follow-up (P < 0.001 for the comparison of the gradient before and after valvuloplasty; P < 0.001 for the comparison before valvuloplasty and at follow-up; and P < 0.05 for the comparison after valvuloplasty and at follow-up). In the same nine patients, the diameter of the pulmonic valve, as measured by right ventricular angiography, increased from 8.3 +/- 1.4 mm before valvuloplasty to 17.2 +/- 2.0 mm after valvuloplasty (P < 0.001) and to 18.4 +/- 1.4 mm at follow-up (P = 0.08). Incompetence of the pulmonic valve was noted in 7 of the 53 patients (13 percent) after balloon valvuloplasty, but it had disappeared at follow-up in all of them. CONCLUSIONS: Patients with congenital pulmonic stenosis who present in late adolescence or adult life can be treated with percutaneous balloon valvuloplasty with excellent short-term and long-term results that are similar to those in young children.

Adolescent↗
PubMed1996

Anti-idiotypic antibodies mimicking glycoprotein D of herpes simplex virus identify a cellular protein required for virus spread from cell to cell and virus-induced polykaryocytosis.

Glycoprotein D (gD) of herpes simplex virus 1 (HSV-1) is required for stable attachment and penetration of the virus into susceptible cells after initial binding. We derived anti-idiotypic antibodies to the neutralizing monoclonal antibody HD1 to gD of HSV-1. These antibodies have the properties expected of antibodies against a gD receptor. Specifically, they bind to the surface of HEp-2, Vero, and HeLa cells susceptible to HSV infection and specifically react with a Mr 62,000 protein in these and other (143TK- and BHK) cell lines. They neutralize virion infectivity, drastically decrease plaque formation by impairing cell-to-cell spread of virions, and reduce polykaryocytosis induced by strain HFEM, which carries a syncytial (syn-) mutation. They do not affect HSV growth in a single-step cycle and plaque formation by an unrelated virus, indicating that they specifically affect the interaction of HSV gD) with a cell surface receptor. We conclude that the Mr 62,000 cell surface protein interacts with gD to enable spread of HSV-1 from cell to cell and virus-induced polykaryocytosis.

Animals↗
PubMed1996

The secondary structure of a pyrimidine-guanine sequence-specific ribonuclease possessing cytotoxic activity from the oocytes of Rana catesbeiana.

RC-RNase is a pyrimidine-guanine sequence-specific ribonuclease and a sialic-acid-binding lectin purified from Rana catesbeiana (bullfrog) oocytes. This 111-amino acid protein exhibits cytotoxicity toward several tumor cell lines. In this paper we report the assignments of proton NMR resonances and the identification of the secondary structure deduced from NOE constraints, chemical shift index, 3JNH alpha and amide proton exchange rates. The protein was directly isolated from bullfrog oocytes; we were able to assign all but five of the amino acid backbone protons of the unlabeled protein by analyzing a large set of two-dimensional proton NMR spectra obtained at several temperatures and pH conditions. Our results indicate that the structure of RC-RNase is dominated by the presence of two triple-stranded antiparallel beta-sheets and three alpha-helices, similar to those of the pyrimidine family ribonucleases. Two sets of resonances were observed for 11 amide protons and 8 alpha-protons located in the loop-1 region, an alpha 2 helix, and three beta-strands, (beta 1, beta 3 and beta 4), suggesting the presence of nonlocalized multiple conformations for RC-RNase.

Amino Acid Sequence↗
PubMed1996

The use of piezo micromanipulation for intracytoplasmic sperm injection of human oocytes.

INTRODUCTION: This paper describes the use of piezo actuator technology for intracytoplasmic sperm injection of human eggs. METHODS: Piezo micromanipulation involves a simple and easily made injection pipette of very thin diameter and wall thickness, and it has recently been developed using a mouse model. No bevel or spike is required on the pipettes used. The piezo actuator attaches to conventional micromanipulators and acts to mechanically advance the pipette tip through the zona pellucida using a piezoelectric effect. The oolemma could, in some cases, also be broken using piezo. This technique was applied to 39 patients presenting for in vitro fertilization due to male-factor infertility. RESULTS: The fertilization rate of eggs injected (60.5%), damage rate (7.6%), abnormality rate (3%), and ongoing pregnancy rate beyond 8 weeks (28.2%) are comparable to those for other techniques that have been successfully reported.

Female↗
PubMed1996

Prevention and management of related complication due to laparoscopic operation: pneumothorax, pneumomediastinum and subcutaneous emphysema.

Essential prerequisite of laparoscopic operation is establishing and maintaining pneumoperitoneum with a certain pressure. But under certain circumstances CO2-gas insufflating could induce pneumothorax, pneumomediastinum and subcutaneous emphysema during the operation. to probe the mechanism of the above complications. 2 typical cases were reported with attempt to probe the mechanism of the development of such applications. We believe that high intra-abdominal pressure during operation is the primary cause of the complications. The essentials of prevention and management of such complications were proposed.

Adult↗