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Biomedical subjects

Y J Hu

Publications and source records attributed to Y J Hu.

At least 37 records · Page 2Linked to original sources
PubMed2000

What determines severity among patients with painful functional bowel disorders?

OBJECTIVE: For patients with painful functional bowel disorders (FBD), physicians frequently make diagnostic and treatment decisions based on the severity of the pain reported; patients with severe painful complaints may receive extensive diagnostic tests and treatments. Therefore, it would be important to determine what clinical factors contribute to the judgment of severity among patients with FBD. The aim of this study was to identify the psychosocial, behavioral, and physiological (visceral sensitivity) factors that predicted severity in patients with moderate to severe FBD. METHODS: Two hundred eleven female patients with moderate or severe FBD, as determined by the Functional Bowel Disorder Severity Index, entered a multicenter treatment trial at the University of North Carolina and the University of Toronto. Patients filled out diary cards and were given questionnaires and physiological testing (rectal sensitivity using barostat). Analysis of covariance and logistic regression adjusting for demographic factors were performed to determine which factors distinguished patients at study entry with moderate from those with severe FBD. RESULTS: Patients with severe FBD were characterized by greater depression and psychological distress, poorer physical functioning and health-related quality of life, more maladaptive coping strategies, and greater health care utilization. There was a trend for patients with severe FBD to have lower rectal sensation thresholds. Regression analysis indicated that severity was best predicted by behavioral features: poorer daily physical function, difficulties related to eating, more phone calls to the physician, and more days in bed for GI symptoms. CONCLUSIONS: We conclude that patient illness behaviors are best correlated with severity in FBD. The use of psychopharmacological agents (e.g., antidepressants) and psychological treatments to treat psychiatric comorbidity and to improve behavioral coping styles is recommended. Training to help medical physicians identify and respond to psychosocial and behavioral features of these conditions is likely to improve patient satisfaction with their care and the clinical outcome.

Adolescent↗
PubMed2000

[Analysis of the proportion of salivary gland tumors in 528 elder patients].

OBJECTIVE: To analyse the clinical characteristic, evolution and prognosis of undifferentiated carcinoma with lymphoid stroma(malignant lymphoepithelial The purpose of this study was to investigate the present proportional ratio of salivary gland tumors in elder patients, to provide references for early diagnosis and treatment clinically. METHODS: The medical data of 528 elder patients with salivary gland tumors treated in our department in 1990s were reviewed and analyzed. RESULTS: The number of salivary gland tumors in elder patients had increased in recent years. These tumors were frequently found in patients of 60-74 years. The ratio of benign to malignant was 1.7:1. In benign tumors, the proportion of adenolymphoma approached pleomorphic adenoma. While in malignant tumors, adenoid cystic carcinoma accounted the most. These tumors were most commonly found in the parotid gland, followed by the palate. The prevalence of female had an increase trend. CONCLUSION: The proportion of salivary gland tumor in elder patients in 1990s was different from that in 1980s. This change should attract enough attention form the surgeons.

English Abstract↗
PubMed1999

Negative transcriptional regulation mediated by thyroid hormone response element 144 requires binding of the multivalent factor CTCF to a novel target DNA sequence.

DNA target sites for a "multivalent" 11-zinc-finger CCTC-binding factor (CTCF) are unusually long ( approximately 50 base pairs) and remarkably different. In conjunction with the thyroid receptor (TR), CTCF binding to the lysozyme gene transcriptional silencer mediates the thyroid hormone response element (TRE)-dependent transcriptional repression. We tested whether other TREs, which in addition to the presence of a TR binding site require neighboring sequences for transcriptional function, might also contain a previously unrecognized binding site(s) for CTCF. One such candidate DNA region, previously isolated by Bigler and Eisenman (Bigler, J., and Eisenman, R. N. (1995) EMBO J. 14, 5710-5723), is the TRE-containing genomic element 144. We have identified a new CTCF target sequence that is adjacent to the TR binding site within the 144 fragment. Comparison of CTCF recognition nucleotides in the lysozyme silencer and in the 144 sequences revealed both similarities and differences. Several C-terminal CTCF zinc fingers contribute differently to binding each of these sequences. Mutations that eliminate CTCF binding impair 144-mediated negative transcriptional regulation. Thus, the 144 element provides an additional example of a functionally significant composite "TRE plus CTCF binding site" regulatory element suggesting an important role for CTCF in cooperation with the steroid/thyroid superfamily of nuclear receptors to mediate TRE-dependent transcriptional repression.

Animals↗
PubMed1999

Determination of substrate specificity for peptide deformylase through the screening of a combinatorial peptide library.

Peptide deformylase is an essential Fe2+ metalloenzyme that catalyzes the removal of the N-terminal formyl group from nascent polypeptides in eubacteria. In vivo, the deformylase is capable of deformylating most of the polypeptides in a bacterial cell, which contain diverse N-terminal sequences. In this work, we have developed a combinatorial method to systematically examine the sequence specificity of peptide deformylase. A peptide library that contains all possible N-terminally formylated tetrapeptides was constructed on TentaGel resin, with a unique peptide sequence on each resin bead. Limited treatment with the Escherichia coli deformylase resulted in the deformylation of those peptides that are the most potent substrates of the enzyme. By using an enzyme-linked assay, the beads containing the deformylated peptides were identified and isolated. Peptide sequence analysis using matrix-assisted laser desorption ionization mass spectrometry revealed a consensus sequence, formyl-Met-X-Z-Tyr (X = any amino acid except for aspartate and glutamate; Z = lysine, arginine, tyrosine, or phenylalanine), for the E. coli enzyme. The deformylase is also capable of efficient deformylation of formyl-Phe-Tyr-(Phe/Tyr) peptides. These results demonstrate that, despite being a broad-specificity enzyme, the peptide deformylase deformylates different peptides at drastically different rates. In addition, the selectivity of peptide deformylase for the N-formyl over the N-acetyl group has been studied with N-alpha-fluoroacetyl peptides, and the results suggest that both electronic and steric factors are responsible for the observed specificity. The deformylase was also shown to exhibit esterase activity. These results will facilitate the design of specific deformylase inhibitors as potential antibacterial agents. This combinatorial method should be generally applicable to the study of the substrate specificity of other acylases and peptidases.

Amidohydrolases↗
PubMed1998

H-phosphonate derivatives as novel peptide deformylase inhibitors.

Peptide deformylase catalyzes the removal of the N-terminal formyl group from nascent polypeptides during prokaryotic protein maturation and is essential for bacterial survival. Its absence from eukaryotic organisms makes it an attractive target for designing novel antibacterial agents. Peptidyl H-phosphonates were synthesized and shown to be competitive inhibitors of the deformylase.

Amidohydrolases↗
PubMed1998

Temperature threshold and preservation of signaling for mitochondrial membrane proteins during ischemia in rabbit heart.

Temperature modulates both myocardial energy requirements and production. We have previously demonstrated that myocardial protection induced by hypothermic adaptation preserves expression of genes regulating heat shock protein and the nuclear-encoded mitochondrial proteins, the adenine nucleotide translocator isoform 1 (ANT1), and the beta subunit of F1-ATPase (beta F1-ATPase). This preservation is associated with a reduction in ATP depletion similar to that noted in cardioplegic arrested hearts preserved at a critical temperature (30 degrees C) or below. We tested the hypothesis that expression of these genes may also be subject to this temperature threshold phenomenon. Isolated perfused rabbit hearts were subjected to ischemic cardioplegic arrest at 4, 30, or 34 degrees C for 120 min. Cardiac function indices and steady-state mRNA levels for ANT1, beta F1-ATPase, and HSP70-1 were measured prior to ischemia (B) and after 45 min of reperfusion. Cardiac function was significantly depressed in the 34 degrees C group. Ischemia at 34 degrees C reduced steady-state mRNA levels for ANT1 and beta F1-ATPase from B, but these levels were similarly preserved at 4 and 30 degrees C. HSP70-1 levels were mildly elevated (fourfold) above B to similar levels at all three temperatures. These results indicate that mRNA expression for ANT1 and beta F1-ATPase is specifically preserved in a pattern consistent with the temperature threshold phenomenon. HSP70-1 expression is not influenced by ischemic temperature. Preservation of gene expression for these mitochondrial proteins implies that signaling for mitochondrial biogenesis or resynthesis is maintained after ischemic insult.

Animals↗
PubMed1998

Selected symptoms associated with sexual and physical abuse history among female patients with gastrointestinal disorders: the impact on subsequent health care visits.

BACKGROUND: Despite a growing literature pointing to the deleterious health effects of sexual and physical abuse history, few studies provide evidence about which medical symptoms are most affected. The aim of this paper is to determine the impact of sexual and physical abuse history on a selected set of medical symptoms, and to test how such abuse, medical symptoms and functional disability may affect subsequent health care visits. METHODS: We studied 239 women from a referral-based gastroenterology clinic; follow-up data were available on 196 of these women. All women were interviewed about sexual and physical abuse history. RESULTS: Women with abuse history, particularly those with severe abuse, were much more likely to report somatic symptoms related to panic (e.g. palpitations, numbness, shortness of breath), depression (e.g. difficulty sleeping, loss of appetite), musculoskeletal disorders (e.g. headaches, muscle aches), genito-urinary disorders (e.g. vaginal discharge, pelvic pain, painful intercourse), skin disturbance (e.g. rash) and respiratory illness (e.g. stuffy nose). Furthermore, we found that the severity of abuse history, somatic symptoms and functional disability predicted 30% of the variance in health care visits during the subsequent year, and that the effect of abuse severity on visits was explained by abused women having more somatic symptoms and functional disability. CONCLUSIONS: Patients' reports of abuse history, somatic symptoms and functional disability appear to be important factors in explaining the number of health care visits among a clinic sample of women with gastrointestinal disorders.

Adolescent↗
PubMed1998

Hypothermia preserves function and signaling for mitochondrial biogenesis during subsequent ischemia.

Hypothermia is known to protect myocardium during ischemia, but its role in induction of a protective stress response before ischemia has not been evaluated. As cold incites stress responses in other tissues, including heat shock protein induction and signaling mitochondrial biogenesis, we postulated that hypothermia in perfused hearts would produce similar phenomena while reducing injury during subsequent ischemia. Studies were performed in isolated perfused rabbit hearts (n = 77): a control group (C) and a hypothermic group (H) subjected to decreasing infusate temperature from 37 to 31 degrees C over 20 min. Subsequent ischemia during cardioplegic arrest at 34 degrees C for 120 min was followed by reperfusion. At 15 min of reperfusion, recovery of left ventricular developed pressure (LVDP), maximum first derivative of left ventricular pressure (LV dP/dtmax), LV -dP/dtmax, and the product of heart rate and LVDP was significantly increased in H (P < 0.01) compared with C hearts. Ischemic contracture started later in H (97.5 +/- 3.6 min) than in C (67.3 +/- 3.3 min) hearts. Myocardial ATP preservation and repletion during ischemia and reperfusion were higher in H than in C hearts. mRNA levels of the nuclear-encoded mitochondrial proteins adenine nucleotide translocase isoform 1 (ANT1) and beta-F1-adenosine-triphosphatase (beta-F1-ATPase) normalized to 28S RNA decreased in C hearts but were preserved in H hearts after reperfusion. Inducible heat shock protein (HSP70-1) mRNA was elevated nearly 4-fold after ischemia in C hearts and 12-fold in H hearts. These data indicate that hypothermia preserves myocardial function and ATP stores during subsequent ischemia and reperfusion. Signaling for mitochondrial biogenesis indexed by ANT1 and beta-F1-ATPase mRNA levels is also preserved during a marked increase in HSP70-1 mRNA.

Adenine Nucleotides↗
PubMed1997

The protective role of selenium on the toxicity of cisplatin-contained chemotherapy regimen in cancer patients.

The effect of selenium (Se) in reducing the toxicity of cisplatin in cancer patients was studied. Forty-one patients were randomized into group A (20 patients with Se administration in first cycle of chemotherapy as study cases and without Se in second cycle of chemotherapy as control) and group B (21 patients without Se in first cycle of chemotherapy and with Se in second cycle of chemotherapy). The 4000 micrograms per day of Se as Seleno-Kappacarrageenan were administered from 4 before to 4 d after chemotherapy for study cases. The serum Se increased from 70.4 +/- 22.86 to 157.04 +/- 60.23 ng/mL (P < 0.001) in patients received Se. The cisplatin dosage was iv administration in 60-80 mg/m2 on the first day. The results showed that the peripheral WBC counts on day 14 after initiation of chemotherapy in study cases was significantly higher than the controls (3.35 +/- 2.01 vs 2.31 +/- 1.38 [x10(9)L])/L, p < 0.05). On the other hand, the consumption of GCSF for the cases was significantly less than the controls (110.1 +/- 82.2 vs 723.6 +/- 192.6 IU, p < 0.05). The volumes of blood transfusion for the study group were also significantly less than the controls (0 vs 62 +/- 38 mL, p < 0.05). The nephrotoxicity of cisplatin was measured by urine enzymes (NAG, GGT, AAP, LAP, and ALP) were determined prior to and at 2, 24, 48, and 72 h after initiation of chemotherapy. The urine enzymes NAG, GGT, AAP, and ALP after chemotherapy for cases were significantly lower than the controls. No toxicity of Seleno-Kappacarrageenan was noted. The above results suggest that the Se can be used as an agent for reducing the nephrotoxicity and bone marrow suppression induced by cisplatin.

Administration, Oral↗
PubMed1997

An endoglucanase from the anaerobic fungus Orpinomyces joyonii: characterization of the gene and its product.

An endoglucanase gene (celA) was isolated from a genomic library of the ruminal fungus Orpinomyces joyonii. DNA sequence analysis of celA revealed an intronless gene encoding a typical signal sequence, an N-terminal catalytic domain, two repeated regions linked by a short Ser/Thr-rich linker and a domain of unknown function. The deduced amino acid sequence of the catalytic domain showed homology with the family 5 cellulases. While the catalytic domain of CelA was not homologous to the catalytic domain of the endoglucanase gene (EG3) from the ruminal bacterium Fibrobacter succinogenes, the repeated regions of CelA were very similar to the noncatalytic domain of EG3. This suggests that evolutionary shuffling of endoglucanase domains might occur among bacteria and fungi within the anaerobic ecosystem of the rumen. The celA gene was expressed in Escherichia coli, and the periplasmic endoglucanase was used for the characterization studies of the enzyme. CelA exhibited both endoglucanase and xylanase activities. Its pH optimum was 4 and the temperature optimum was 40 degrees C. Deletion analysis showed that the repeated sequences and C-terminal domain of CelA were not required for enzyme activity.

Amino Acid Sequence↗
PubMed1996

Health status by gastrointestinal diagnosis and abuse history.

BACKGROUND & AIMS: Standardized assessment of health status by diagnosis (functional vs. organic) and the relative influence of abuse history on health status have not been studied previously. The aim of this study was to estimate the health status and abuse history for gastrointestinal diagnoses among patients seen in a tertiary-care gastroenterology clinic and to evaluate the relative predictive effects of diagnosis and abuse history on health status. METHODS: Standardized measures of sexual and physical abuse history and six health status measures were estimated for the patients by diagnosis. Analysis of covariance was performed to determine the relative contributions of diagnosis type and abuse history on the health status measures. RESULTS: Patients with functional gastrointestinal diagnoses had poorer health status and a higher frequency of severe types of abuse than patients with structural diagnoses. Independent of abuse history, functional diagnosis was significantly associated with greater pain severity and psychological distress and poorer daily function. Independent of diagnosis, abuse history significantly contributed to greater pain severity, more days in bed, more psychological distress, and poorer daily function. CONCLUSIONS: The type of diagnosis and abuse history independently contributed to the health status of this population. Therefore, medical symptoms alone may not be sufficient to understand patients' health status. Attention must also be paid to contributing psychosocial factors.

Activities of Daily Living↗
PubMed1996

[Cloning and screening on tumor-related genes inactivated in rat hepatoma cells. II. Reversion of malignant phenotype of hepatoma cells].

A rat normal expressing cDNA library was established and subsequently its whole DNA was transfected into CBRH-7919 rat hepatoma cell cultures. With neomycin selection and morphological distinction, several reversed colonies were isolated and subcloned. All these colonies showed decreased growth rates, reduced capacity for foci formation on soft agar and tumorigenicity in nude mice compared to CBRH-7919. Analysis of rescued plasmid cDNA from these colonies is under way.

Animals↗
PubMed1996

[Studies on the chemical constituents of Dregea sinensis Hemsl].

Two new compounds named dresigenin B and dresioside I were isolated from the root of Dregea sinensis Hemsl. Their structures were demonstrated as 20-O-(2-methylbutyryl) tomentogenin and dihydrosarcostin 3-O-beta-D-thevetopyranosyl (1-4)-beta-D-oleandropyranosyl (1-4)-beta-D-cymaropyranoside by spectral evidence.

Drugs, Chinese Herbal↗
PubMed1995

[Study of relationship between level of serum selenium and syndrome differentiation and typing of traditional Chinese medicine in lung cancer].

The relationship between the Syndrome differentiation and typing of TCM and the level of serum Se in the patients with the primary lung cancer was studied. The results revealed that the changed level of serum Se reflected the wax and wane of the pathogenic factors and body resistance in the patients with lung cancer. The level of serum Se gradually decreased as a result of the reducing body resistance and strengthening pathogenic factors, which suggested that it facilitated the evaluation of the patients' condition, recovery and prognosis of lung cancer. Due to the level of serum Se was lowered with the using of some chemotherapeutic agents, and through the treatment of lung cancer with the Syndrome Differentiation of TCM, it could supplement chemotherapy and maintain the serum Se level. It suggested that some Chinese medicinal herbs rich in Se should be selected to treat lung cancer so as to improve the therapeutic effect.

Adult↗
PubMed1994

[Cloning and screening on tumor-related genes inactivated in rat hepatoma cells].

The paper describes an experiment screening tumor-related genes which specifically expressed in rat normal liver cells but inactivated in hepatoma cells with subtractive hybridization technique. During the test, subtracting normal liver cDNA with hepatoma mRNA produces probe-A whereas subtracting hepatoma cDNA by normal liver mRNA gives probe-B. The paper shows six cDNA fragments (TR 1-6) which hybridize probe-A preferentially obtained through dot-blot screening of 2500 colonies with the two probes. Among TR 1-6, special expressions of TR 2 and TR 4 in normal liver cells are further analyzed.

Animals↗