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Biomedical subjects

J Lim

Publications and source records attributed to J Lim.

At least 91 records · Page 5Linked to original sources

The emergence of dieting among female adolescents: age, body mass index, and seasonal effects.

OBJECTIVE: The purpose of this brief report is to document the emergence of dieting in adolescent girls across a 2-year period, and to establish whether the changes in dieting status were related to the girls' age, body mass index, or to seasonal effects. METHOD: As part of a large-scale longitudinal study concerned with adolescent health and well-being, 478 girls, initially aged 12 to 16 years old, completed Strong and Huon's (Eating Disorders 5:97-104, 1997) dieting status measure on four separate occasions across a 2-year period. RESULTS: A total of 273 girls (57.1%) identified themselves as nondieters when we first visited their school. Of those, approximately 20% indicated that they had begun to diet on one of the subsequent testing occasions. The emergence of dieting was observed to occur more in the 13- and 14-year-olds than in any other age group. Higher body mass index was not associated with the initiation of dieting as some underweight, and even very underweight girls, began to diet. DISCUSSION: The emergence of dieting occurs in early adolescence and might be triggered by concerns about changes in body shape.

Adolescent↗

Pathways to serious dieting: significant insights from discontinuity.

OBJECTIVES: This paper outlines a strategy for systematically examining the discontinuity in pathways to serious dieting. METHOD: Eight hundred and twenty-three adolescent females were recruited from six high schools in metropolitan Sydney, Australia. They completed a battery of measures that assessed perceived social influences to diet, predisposition to conformity, protective skills, aspects of positive familial context, and dieting-related attitudes and status. Testing took place over two occasions approximately 10 months apart. RESULTS: Family context, protective skills, and a predisposition to conformity were found to differentiate the vulnerable girls who reported high levels of social influence from those who did not. However, those variables did not differentiate those with high social influence who seriously diet from nondieters. Body mass index, drive for thinness, and body dissatisfaction differentiated all of the comparison groups tested. Age did not consistently differentiate these groups. DISCUSSION: The findings can tell us what seems to protect girls who appear susceptible to social influences from becoming serious dieters.

Adaptation, Psychological↗

Social influences and female adolescent dieting.

A large sample of female adolescents whose ages ranged from 12 to 17 years completed a battery of measures assessing their dieting status and their perceived psychosocial influences to diet. Higher levels of perceived influence from parents and peers were reported by girls who were dieting with a greater frequency. While age and social influences significantly predicted dieting status on their own, when examined together, the effect of social influence overrode that for age.

Adolescent↗

Information Technology Support For Debiasing Group Judgments: An Empirical Evaluation.

Human judgments, made by either individuals or groups, have been found to contain biases. One of the most prevalent biases identified is the availability bias, associated with the phenomenon that events which are more available to human memory are correspondingly judged as occurring more frequently or as being more important. This paper is concerned with how to reduce the availability bias in the group context. It reports an experiment in which two computer-based support facilities, electronic brainstorming and electronic mail, were tested for their contributions to reducing the availability bias. A 2 x 2 experimental design was used: electronic brainstorming (available or not) and communication mode (electronic or verbal). Forty teams of three members each were asked to work on a task involving the rating of the importance of a number of items associated with a secretary's task. Both electronic brainstorming and electronic communication helped reduce the availability bias. In both cases, the reduction in bias was due to increased attention paid to items that were found to have low availability in the absence of these support tools. Copyright 2000 Academic Press.

Journal Article↗

Androgen receptor polymorphisms and mutations in male infertility.

Normal spermatogenesis depends on a sequential cascade of genetic events triggered by factors encoded by sex chromosomes. To determine the contribution of genetic aberrations to male infertility, the X-linked androgen receptor (AR) gene was examined for mutations and polymorphisms in a large cohort of infertile men. Genetic screening of over 400 patients and controls showed that defects in the AR gene lead to the production of dysfunctional receptor protein in up to 10% of males with abnormally low sperm production and male infertility. The dozens of mutations and polymorphisms uncovered were associated with subtly reduced intrinsic AR activity, and are of two main categories: polymorphic changes in length of a trinucleotide CAG tract in the N-terminal transactivation domain, and missense mutations in the C-terminal ligand-binding domain. These polymorphisms and mutations are associated with reduced AR function due to defective intermolecular protein-protein interactions with coactivator molecules. Genetic screening for AR mutations and polymorphism should be offered to severely oligospermic and azoospermic patients. These traits can be transmitted to progeny, and counseling can be offered to affected families. Clarification of the molecular mechanisms of pathogenesis has led to rational hormonal therapy.

Humans↗

Structural characterization and transcriptional pattern of two types of carp rhodopsin gene.

This work characterizes the genomic structures of two types of carp (Cyprinus carpio) rhodopsin (cRh) gene, i.e. type I (cRh-I) and type II (cRh-II). Two types of cRh gene share only 45.6% polynucleotide identity in the upstream region from nucleotide -3436 to +97. However, three conserved regions are found. Homologies to the consensus recognition sites for transcription factors, Crx and Nrl, which are involved in photoreceptor-specific expression, are also observed in cRh genes. With specific polymerase chain reaction (PCR) primers, the two types of cRh gene can be clearly discriminated from each carp genome. Most carps exhibit both types of cRh gene, however, there are still carps possessing either cRh-I or cRh-II. Both cRh-I and cRh-II mRNAs are expressed at an approximately equal level in both eyes extracted from a carp carrying both types of cRh gene.

Animals↗

Cardiogenic shock complicating acute myocardial infarction--etiologies, management and outcome: a report from the SHOCK Trial Registry. SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK?

OBJECTIVES: This SHOCK Study report seeks to provide an overview of patients with cardiogenic shock (CS) complicating acute myocardial infarction (MI) and the outcome with various treatments. The outcome of patients undergoing revascularization in the SHOCK Trial Registry and SHOCK Trial are compared. BACKGROUND: Cardiogenic shock is the leading cause of death in patients hospitalized for acute MI. The randomized SHOCK Trial reported improved six-month survival with early revascularization. METHODS: Patients with CS complicating acute MI who were not enrolled in the concurrent randomized trial were registered. Patient characteristics were recorded as were procedures and vital status at hospital discharge. RESULTS: Between April 1993 and August 1997, 1,190 patients with CS were registered and 232 were randomized in the SHOCK Trial. Predominant left ventricular failure (78.5%) was most common, with isolated right ventricular shock in 2.8%, severe mitral regurgitation in 6.9%, ventricular septal rupture in 3.9% and tamponade in 1.4%. In-hospital Registry mortality was 60%, with ventricular septal rupture associated with a significantly higher mortality (87.3%) than all other categories (p < 0.01). The risk profile and mortality were lower for Registry patients who were managed with thrombolytic therapy and/or intra-aortic balloon counter-pulsation, coronary angiography, angioplasty and/or coronary artery bypass surgery. After adjusting for these differences, the extent to which survival was improved with early revascularization was similar to that observed in the randomized SHOCK Trial. CONCLUSIONS: In this prospective Registry the etiology of CS was a mechanical complication in 12%. The similarity of the beneficial treatment effect in patients undergoing early revascularization in the SHOCK Trial Registry and SHOCK Trial provides strong support for the generalizability of the SHOCK Trial results.

Aged↗

Triamcinolone acetonide aqueous nasal spray versus loratadine in seasonal allergic rhinitis: efficacy and quality of life.

BACKGROUND: The new aqueous formulation of triamcinolone acetonide (TAA) was compared with loratadine in patients with seasonal allergic rhinitis. OBJECTIVE: The primary objective of the study was to compare the safety and efficacy of TAA aqueous with loratadine in relieving the symptoms of seasonal allergic rhinitis. METHODS: A total of 351 patients were enrolled into this 4-week, double-blind, double-dummy, randomized, parallel group study. Patients received either TAA aqueous nasal spray (220 microg) or loratadine (10 mg) once daily. Efficacy variables were rhinitis symptom changes from baseline, physician global evaluations, and the patient dropout rate due to insufficient treatment effect. Safety and quality of life also was evaluated. RESULTS: Both TAA aqueous-treated and loratadine-treated patients had improvement in symptoms as early as day 1. Overall, TAA aqueous was significantly (P < .05) more effective than loratadine in reducing total nasal symptoms and individual symptoms of nasal congestion, nasal itch, and sneezing. Ocular symptoms improved from baseline in both groups. There was no statistically significant difference between groups based on physician global evaluation. A similar number of patients in each group discontinued the study due to ineffective treatment. Triamcinolone acetonide aqueous patients maintained a significantly (P < .05) better quality of life in three of the dimensions (activity, nasal symptoms, and practical problems) and for overall quality of life. There were no differences between the two treatment groups in the incidence of adverse events, none of which were clinically significant. CONCLUSIONS: Both TAA aqueous and loratadine were effective and well-tolerated in the treatment of patients with seasonal allergic rhinitis. Triamcinolone acetonide aqueous was significantly (P < .05) more effective than loratadine in controlling nasal symptoms of seasonal allergic rhinitis and maintaining a better quality of life for the patients.

Administration, Intranasal↗

Production of biologically active human granulocyte colony stimulating factor in the milk of transgenic goat.

We have developed a transgenic female goat harboring goat beta-casein promoter/human granulocyte colony stimulating factor (G-CSF) fusion gene by microinjection into fertilized one-cell goat zygotes. Human G-CSF was produced at levels of up to 50 microg/ml in transgenic goat milk. Its biological activity was equivalent to recombinant human G-CSF expressed from Chinese hamster ovary (CHO) cell when assayed using in vitro HL-60 cell proliferation. Human G-CSF from transgenic goat milk increased the total number of white blood cells in C57BL/6N mice with leucopenia induced by cyclophosphamide (CPA). The secreted human G-CSF was glycosylated although the degree of O-glycosylation was lower compared to CHO cell-derived human G-CSF.

Animals↗

Two rice MADS domain proteins interact with OsMADS1.

OsMADS1 is a MADS box gene controlling flower development in rice. In order to learn more about the function of OsMADS1, we searched for cellular proteins interacting with OsMADS1 employing the yeast two-hybrid system. Two novel proteins with MADS domains, which were named OsMADS14 and OsMADS15, were isolated from a rice cDNA library. OsMADS14 and -15 are highly homologous to the maize MADS box gene ZAP1 which is an orthologue of the floral homeotic gene APETALA1 (AP1). Interactions among the three MADS domain proteins were confirmed by in vitro experiments using GST-fused OsMADS1 expressed in Escherichia coli and in vitro translated proteins of OsMADS14 and -15. We determined which domains in OsMADS1, -14, and -15 were required for protein-protein interaction employing the two-hybrid system and pull-down experiments. While the K domain was essential for protein-protein interaction, a region preceded by the K domain augmented this interaction. Interestingly, the C-terminal region of OsMADS1 functioned as a transcriptional activation domain in yeast and mammalian cells, while, on the other hand, the C domains of OsMADS14 and -15 exhibited only very weak transcriptional activator functionality, if any at all.

Amino Acid Sequence↗

Molecular analysis of the SCARECROW gene in maize reveals a common basis for radial patterning in diverse meristems.

Maize and Arabidopsis root apical meristems differ in several aspects of their radial organization and ontogeny. Despite the large evolutionary distance and differences in root radial patterning, analysis of the putative maize ortholog of the Arabidopsis patterning gene SCARECROW (SCR) revealed expression localized to the endodermis, which is similar to its expression in Arabidopsis. Expression in maize extends through the quiescent center, a population of mitotically inactive cells formerly thought to be undifferentiated and to lack radial pattern information. Zea mays SCARECROW (ZmSCR), the putative maize SCR ortholog, was used as a molecular marker to investigate radial patterning during regeneration of the root tip after either whole or partial excision. Analysis of the dynamic expression pattern of ZmSCR as well as other markers indicates the involvement of positional information as a primary determinant in regeneration of the root radial pattern.

Amino Acid Sequence↗

Nonstructural protein 5A of hepatitis C virus inhibits the function of karyopherin beta3.

It has been suggested that nonstructural protein 5A (NS5A) of hepatitis C virus (HCV) plays a role in the incapacitation of interferon by inactivation of RNA-dependent protein kinase PKR. In order to further investigate the role of NS5A, we tried to identify cellular proteins interacting with NS5A by using the yeast two-hybrid system. The karyopherin beta3 gene was isolated from a human liver cell library as a protein interacting with NS5A. The protein-protein interaction between NS5A and karyopherin beta3 was confirmed by in vitro binding assay and an in vivo coimmunoprecipitation method. The effect of NS5A on the karyopherin beta3 activity was investigated using a yeast cell line containing mutations in both PSE1 and KAP123, genes that are homologous to the human karyopherin beta3 gene. Human karyopherin beta3 complemented the loss of the PSE1 and KAP123 functions, supporting growth of the double mutant cells. However, expression of NS5A hampered the growth of the double mutant cells supplemented with human karyopherin beta3. On the other hand, expression of NS5A by itself had no effect on the growth of the double mutant expressing wild-type yeast PSE1. This indicates that NS5A may inhibit karyopherin beta3 function via protein-protein interaction. The role of NS5A in HCV replication is discussed.

Animals↗

Expression of functional markers in acute nonlymphoblastic leukemia.

Multidrug resistance parameters, tissue infiltration parameters, receptors for colony-stimulating factors (CSFr) and cell cycle parameters were analyzed using flow cytometry in 145, 109 initial and 36 relapsed or refractory, acute nonlymphoblastic leukemia (ANLL) patients to find out clinically more reliable functional parameters. Lung resistance-associated protein (LRP) was most frequently expressed in ANLL (44.1%) followed by P-glycoprotein (PGP) (35.9%) and multidrug resistance-associated protein (MRP) (8.3%). LRP and PGP were expressed more frequently in relapsed or refractory ANLL than initial ANLL cases. Complete remission rate after standard chemotherapy falls in PGP-positive cases (p = 0.001). CD44-positive ANLL cases relapsed more frequently. The organ tropism is different depending on the infiltration parameters, vascular cell adhesion molecule to splenomegaly, matrix metalloprotease-2 to hepatomegaly and to extramedullary infiltration other than spleen, liver or lymph node. The percentage of the granulocyte-macrophage-CSFr expression was high in M4 and M5, and granulocyte-CSFr-positive ANLL showed less extramedullary infiltration (p = 0.007) and more PGP expression. Ki-67 was expressed significantly less in refractory ANLL than initial ANLL and DNA topisomerase IIalpha was expressed significantly more in the surviving patients group. In conclusion, analysis of these new functional parameters could help to predict and overcome the clinical behavior of each ANLL at the time of diagnosis.

Adolescent↗

Dexamethasone for the prophylaxis of radiation-induced emesis: a National Cancer Institute of Canada Clinical Trials Group phase III study.

PURPOSE: To investigate the efficacy of dexamethasone as a prophylactic antiemetic for patients receiving fractionated radiotherapy to the upper abdomen in a randomized controlled trial. PATIENTS AND METHODS: One hundred fifty-four patients planned to receive fractionated radiotherapy to fields involving the upper abdomen (minimum total dose, 20 Gy; minimum number of fractions, five) were randomized to receive prophylactic dexamethasone (2 mg orally three times a day [tid], starting in the morning of first treatment and continuing until after their fifth treatment) or placebo. The primary end point of the study was the proportion of patients free from emesis during the study period. Secondary end points included a quality-of-life assessment using the core questionnaire of the European Organization for Research and Treatment of Cancer and side effects of dexamethasone therapy in this population of patients. RESULTS: Fifty-four (70%) out of 75 patients receiving dexamethasone had complete protection versus 37 (49%) out of 75 patients on placebo (P = .025). Most emetic episodes occurred during the initial phase of treatment. Although there was no difference in global quality of life between the two sets of patients, patients receiving dexamethasone had less nausea and vomiting and less loss of appetite but more insomnia. CONCLUSION: Dexamethasone 2 mg tid seems to be an effective prophylactic antiemetic in this situation. Side effects were acceptable, but there seemed to be no overall effect on global quality of life.

Abdomen↗

Human androgen receptor mutation disrupts ternary interactions between ligand, receptor domains, and the coactivator TIF2 (transcription intermediary factor 2).

The androgen receptor (AR) is a ligand-dependent X-linked nuclear transcription factor regulating male sexual development and spermatogenesis. The receptor is activated when androgen binds to the C-terminal ligand-binding domain (LBD), triggering a cascade of molecular events, including interactions between the LBD and the N-terminal transactivation domain (TAD), and the recruitment of transcriptional coactivators. A nonconservative asparagine to lysine substitution in AR residue 727 was encountered in a phenotypically normal man with subfertility and depressed spermatogenesis. This N727K mutation, although located in the LBD, did not alter any ligand-binding characteristic of the AR in the patient's fibroblasts or when expressed in heterologous cells. Nonetheless, the mutant AR displayed only half of wild-type transactivation capacity when exposed to physiological or synthetic androgens. This transactivation defect was consistently present when examined with two different reporter systems in three cell lines, using three androgen-driven promoters (including the complex human prostate-specific antigen promoter), confirming the pathogenicity of the mutation. In mammalian two-hybrid assays, N727K disrupted LBD interactions with the AR TAD and with the coactivator, transcription intermediary factor 2 (TIF2). Strikingly, the transactivation defect of the mutant AR can be rectified in vitro with mesterolone, consistent with the ability of this androgen analog to restore sperm production in vivo. Mesterolone, but not the physiological androgen dihydrotestosterone, restored mutant LBD interactions with the TAD and with TIF2, when expressed as fusion proteins in the two-hybrid assay. Our data support an emerging paradigm with respect to AR mutations in the LBD and male infertility: pathogenicity is transmitted through reduced interdomain and coactivator interactions, and androgen analogs that are corrective in vitro may indicate hormonal therapy.

Amino Acid Sequence↗

Purification and embryotropic roles of tissue inhibitor of metalloproteinase-1 in development of "HanWoo" (Bos taurus coreanae) oocytes co-cultured with bovine oviduct epithelial cells.

This study was conducted to purify a tissue inhibitor of metalloproteinase (TIMP)-1 in a serum-free medium conditioned with bovine oviduct epithelial cells (BOEC) and to evaluate its effect on development of "HanWoo" (Bos taurus coreanae) embryos to the blastocyst stage. In the first study using SDS-PAGE electrophoresis, the presence of 32 kDa proteins, which contains TIMP-1, was detected in the medium conditioned with BOEC, and TIMP-1 was then purified from the medium by gel filtration and HPLC techniques. When examined TIMP-1 secretion, fluorescent foci indicating the secretion of TIMP-1 were found after stained BOEC with fluorescein isothiocyanate. In the next experiment, two-cell embryos derived from in vitro-fertilization were cultured in a serum-free medium, to which 0, 1.25, 2.5 or 5 microg/ml of purified TIMP-1 was supplemented. More (P<0.05) embryos developed to the morula and blastocyst stages after the addition of 2.5 microg/ml to culture medium than after no addition. In conclusion, our data indicate that BOEC secrete TIMP-1 and this glycoprotein promotes the prehatched development of "HanWoo" embryos derived from in vitro-fertilization.

Animals↗

Molecular basis of androgen receptor diseases.

androgens act through a single intracellular androgen receptor (AR) which is encoded by a single-copy gene in the X chromosome. Disruption of the AR by genetic mutation results in complete androgen insensitivity syndrome (CAIS) and the female phenotype in otherwise healthy 46XY individuals. Although CAIS is the best known phenotype, recent studies from our laboratory and elsewhere show that malfunction of the AR is associated with many androgen-regulated diseases or conditions that cross traditional clinical disciplines ranging from paediatrics (ambiguous genitalia), gynaecology (primary amenorrhoea), urology (prostate cancer), neurology (spinal bulbar muscular atrophy), reproductive medicine (male infertility), orthopedics (rheumatoid arthritis), oncology (breast cancer) and dermatology (hirsutism, baldness and acne). Of particular interest are the roles that polymorphic CAG trinucleotide repeat tracts and subtle mutations in the AR ligand-binding domain have in the aetiology of male infertility and prostate cancer, two conditions affecting large numbers of patients. Novel mechanisms of pathogenesis have been uncovered in these cases, and they involve defective protein-protein interactions with coregulator molecules such as TIF2 (transcriptional intermediary factor 2). Knowledge of the critical role that the AR plays in the pathogenesis of these diverse conditions has led to improved diagnostic methods and successful therapy.

Androgen-Insensitivity Syndrome↗