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Biomedical subjects

J H Hsu

Publications and source records attributed to J H Hsu.

At least 19 recordsLinked to original sources

Effect of composting on characterization and leaching of copper, manganese, and zinc from swine manure.

This research was conducted to study the influence of composting on the concentrations, water solubility, and phase association of Cu, Mn, and Zn from swine (Sus domesticus) feces. Composting of separated swine manure was performed in two piles for 122 days. The metal concentrations increased rapidly during the first 49 days and leveled off thereafter. All metal concentrations increased approximately 2.7-fold in the final compost due to decomposition of organic matter. A sequential extraction protocol was used to evaluate the humification process and partition metals into water-soluble, exchangeable, organically complexed, organically bound, solid particulate, and residual fractions. Temporal changes in the water-soluble fractions of Cu, Mn, and Zn were reflected by water-soluble organic C concentrations, which rapidly increased to a maximum at Day 18 and declined thereafter. An increase in the humic acid/fulvic acid ratio in Na4P2O7 or NaOH extracts at various stages of composting represented the humification process. During composting, the major portions of Cu, Mn, and Zn were in the organically-bound, solid particulate, and organically complexed fractions, respectively. Metal distributions in different chemical fractions were generally independent of composting age and, thus, independent of respective total metal concentrations in the composts.

Animals↗

Nosocomial Exophiala jeanselmei pseudoinfection after sonography-guided aspiration of thoracic lesions.

BACKGROUND AND PURPOSE: During the period from August 1994 to October 1998, a total of 19 isolates of Exophiala jeanselmei were recovered from 17 patients with various underlying thoracic diseases treated at National Taiwan University Hospital. The purpose of this study was to describe the clinical characteristics of these patients and to determine the microbiologic relatedness of the E. jeanselmei. METHODS: Of the 19 isolates, 11 from nine patients were preserved and were identified based on their biotypes as determined by the API ID32C System, their cellular fatty acid profiles by gas-liquid chromatography, their antibiotypes to five antifungal agents by the E-test, and their random amplified polymorphic DNA (RAPD) patterns by arbitrarily primed PCR. Extensive environmental surveillance cultures and cultures from the skin of eight patients and hands of one physician were also performed. RESULTS: One of the 17 patients had E. jeanselmei isolated from cutaneous phaeohyphomycosis (3 isolates), and the other 16 patients had isolations from pleural effusion specimens (15 isolates) or lung mass (1 isolate) following sonography-guided aspiration. The latter 16 patients had no clinical or pathologic evidence of fungal infection. Isolates (clone 1) from aspirated specimens had identical biotypes, antibiotypes, and RAPD patterns, which were different from those of the three isolates (clone 2) from the patient with a cutaneous lesion. All specimens from environmental sources, patients' skin, and the hands of the physician were negative for E. jeanselmei. CONCLUSION: This series of patients demonstrates the difficulty in identifying the sources of a nosocomial pseudoinfection due to this slow-growing microorganism when isolated from pleural effusion specimens.

Adult↗

Molecular evidence for strain dissemination of Penicillium marneffei: an emerging pathogen in Taiwan.

From January 1987 through December 1998, Penicillium marneffei infection (23 patients) or colonization (1 patient) was diagnosed in a total of 24 patients in Taiwan. Of these 24 patients, 16 (67%) had AIDS and 20 (83%) had disseminated P. marneffei infection. The majority (63%) of the infections were considered indigenous. The number of cases has increased markedly in recent years, with 17 of the 24 cases diagnosed from 1996 through 1998. Twenty preserved isolates of P. marneffei, recovered from 11 patients treated at National Taiwan University Hospital during the period of January 1996 through December 1998, were studied to determine the epidemiology of P. marneffei infections. Among the 20 isolates, a total of 8 strains (highly related isolates) were identified on the basis of tests for susceptibility to 5 antifungal agents, for chromosomal DNA restriction fragment-length polymorphism types, and for randomly amplified polymorphic DNA patterns. One of the strains (6 isolates) was isolated from 4 patients treated in 1997 and 1998. Strain spreading of P. marneffei may partially contribute to the increased number of infections caused by this organism in immunosuppressed patients in Taiwan.

Adolescent↗

Gastrointestinal metastasis in hepatocellular carcinoma: radiological and endoscopic studies of 11 cases.

BACKGROUND: From October 1990 to January 1999, 11 of 2237 hepatoma patients at our hospital had gastrointestinal tract metastasis. We describe the radiological and endoscopic features, clinical course and prognoses of those patients. METHODS: All patients were male. Six patients were hepatitis B carriers, and cirrhosis was noted in eight patients on admission. We reviewed all available radiological, endoscopic and pathological features. RESULTS: The commonest clinical presentation was frank gastrointestinal bleeding. Histological proof of gastrointestinal involvement was seen in six patients. Endoscopic features included ulcerative tumours mimicking advanced gastric carcinoma (43%) and submucosal tumours (29%). The sites of organ involvement were stomach (five), duodenum (two), colon (three) and duodenum and colon (one). Direct invasion by a contiguous neoplasm was the major route of gastrointestinal tract metastasis. Portal vein thrombosis may be the key point of haematogenous spread to other sites. CONCLUSIONS: The prognosis in these patients was extremely poor. Almost all patients died within 5 months if no further aggressive management was performed. Surgical intervention may be the optimal choice for palliative treatment of HCC with gastrointestinal tract involvement.

Aged↗

Impact of Helicobacter pylori eradication on the development of MALT, gland atrophy and intestinal metaplasia of the antrum.

BACKGROUND: Chronic Helicobacter pylori infection leads to the development of mucosa-associated lymphoid tissue (MALT), gland atrophy, intestinal metaplasia, and in certain individuals, gastric lymphoma and adenocarcinoma. We conducted a prospective study to determine the effect of H pylori eradication on the development of MALT, gland atrophy and intestinal metaplasia. METHODS: From July 1995 to October 1996, 63 consecutive patients with H pylori-associated peptic ulcer disease were enrolled in a bacterial eradication trial. The grade of MALT and the degree of gastritis of the antrum were assessed using Wotherspoon's scale and the Sydney system before treatment, and at eight weeks and one year after H pylori eradication therapy. RESULTS: During the study period, 43 patients received complete follow-up. In the patient group with eradication failure (n = 22), MALT score was significantly decreased at the end of the eighth week (p < 0.05) but returned to the initial level by one year of follow-up. There were no changes in the scores for inflammation, neutrophil activity, gland atrophy or intestinal metaplasia at the end of the eighth week and at one year following H pylori eradication therapy. In contrast, there was a marked reduction in the MALT, inflammation, and activity scores at eight weeks (p < 0.01, < 0.05 and < 0.05, respectively) and one year after treatment (p < 0.05, < 0.001 and < 0.001, respectively) in the patient group with successful eradication (n = 21). However, no significant changes in gland atrophy and intestinal metaplasia were observed during the follow-up period. CONCLUSIONS: Eradication of H pylori leads to regression of MALT in the stomach, but the degrees of gland atrophy and intestinal metaplasia remain unchanged, even after one-year of follow-up.

Adult↗

Long-term effect of large biliary endoprostheses in high-risk surgical patients with irretrievable common bile duct stones.

BACKGROUND: Endoscopic sphincterotomy and basket extraction are currently used to remove bile duct stones, with a duct clearance rate of 85% to 90%. A biliary endoprosthesis (stent) is an alternative method to treat difficult cases, especially high-risk surgical patients. The aim of this study was to investigate the long-term effect of biliary endoprostheses in patients with irretrievable common bile duct stones. METHODS: From December, 1990, to November, 1998, 546 patients were referred to the Veterans General Hospital-Kaohsiung for endoscopic removal of common bile duct stones. Of them, 12 received long-term biliary endoprosthesis because endoscopic removal or surgery was not suitable. Large-caliber stents (> 10 French) were inserted into 12 patients (5 women and 7 men, mean age, 78.4 years) and they were followed up with regular clinical visits. Quantitative cholescintigraphy was performed in four patients to evaluate biliary emptying after liver function returned to normal. RESULTS: No early complications from stent insertion occurred and a satisfactory resolution of jaundice, pain and fever were noted in all patients. One patient had repeated cholangitis due to stent occlusion and five died from unrelated causes. The median effective period of stent placement was 11 months (range, 1-38 months). Quantitative cholescintigraphy revealed delayed biliary drainage in four patients despite an absence of symptoms after their liver function returned to normal. CONCLUSIONS: Large-caliber stents are a safe and effective treatment for long-term palliation in high-risk patients with retained common bile duct stones.

Aged↗

Effect of D57N mutation on membrane activity and molecular unfolding of cobra cardiotoxin.

Cobra cardiotoxins (CTXs) are able to adopt a three-fingered beta-strand structure with continuous hydrophobic patch that is capable of interacting with zwitterionic phospholipid bilayer. In addition to the four disulfide bonds that form the rigid core of CTXs, Asp57 near the C-terminus interacts electrostatically with Lys2 near the N-terminus (Chiang et al. 1996. Biochemistry. 35:9177-9186). We indicate herein, using circular dichroism and the time-resolved polarized tryptophan fluorescence measurement, that Asp57 to Asn57 (D57N) mutation perturbs the structure of CTX molecules at neutral pH. The structural stability of the D57N mutant was found to be lower, as evidenced by the reduced effective concentration of the 2,2,2-trifluoethanol (TFE)-induced beta-sheet to alpha-helix transition. Interestingly, the single mutation also allows a greater degree of molecular unfolding, because the rotational correlation time of the TFE-induced unfolding intermediate is larger for the D57N mutant. It is suggested that the electrostatic interaction between N- and C-termini also contributes to the formation of the functionally important continuous hydrophobic stretch on the distant end of CTX molecules, because both the binding to anilinonaphthalene fluorescent probe and the interaction with phospholipid bilayer were also reduced for D57N mutant. The result emphasizes the importance of the hydrophobic amino acid residues near the tip of loop 3 as a continuous part of the three-fingered beta-strand CTX molecule and indicates how a distant electrostatic interaction might be involved. It is also implicated that electrostatic interaction plays a role in expanding the radius of gyration of the folding/unfolding intermediate of proteins.

Anilino Naphthalenesulfonates↗

Serum endothelin and atrial natriuretic peptide in cirrhotic patients with ascites and hepatorenal syndrome.

BACKGROUND: The pathogenesis of cirrhotic ascites and hepatorenal syndrome remains unresolved. The involvement of both endothelin-1 and atrial natriuretic peptide have recently been suggested. This study investigated the concentrations of serum endothelin and atrial natriuretic peptide in cirrhotic patients. METHODS: Seven healthy subjects and 31 cirrhotic patients were studied. Cirrhotic patients were divided into three groups: Group I, 16 cirrhotic patients without ascites; Group II, 10 cirrhotic patients with ascites, but without hepatorenal syndrome; and Group III, five cirrhotic patients with hepatorenal syndrome and ascites. Their sera were analyzed for endothelin-1 and atrial natriuretic peptide concentrations. RESULTS: Cirrhotic patients with ascites, Group II and Group III, had higher plasma endothelin-1 concentrations (15.9 +/- 2.3 pg/ml and 24 +/- 2.1 pg/ml, respectively) than normal subjects and compensated cirrhotics (3.8 +/- 0.7 pg/ml and 6.4 +/- 1.1 pg/ml, respectively); p < 0.001). Atrial natriuretic peptide concentrations were also significantly higher in cirrhotic patients than in normal subjects (p < 0.025). Plasma endothelin-1 concentration had a negative correlation with creatinine clearance (r = -0.65, p < 0.001), as did atrial natriuretic peptide concentrations (r = -0.44, p = 0.012). Plasma endothelin-1 correlated significantly with atrial natriuretic peptide concentrations (r = 0.38, p = 0.035). CONCLUSIONS: Both endothelin-1 and atrial natriuretic peptide concentrations were elevated in cirrhotic patients with ascites and hepatorenal syndrome. Endothelin-1 may have a negative impact on renal function. Our data also suggested that impaired responsiveness rather than impaired secretion of atrial natriuretic peptide is responsible for sodium retention in cirrhotic patients with ascites.

Adult↗

Effect of megestrol acetate and prepulsid on nutritional improvement in patients with head and neck cancers undergoing radiotherapy.

BACKGROUND AND PURPOSE: Anorexia is a common problem in cancer patients who receive radiotherapy. In this current study, we attempt to determine the effect of megestrol acetate and prepulsid on appetite and nutritional improvement in patients with head and neck cancers undergoing radiotherapy. MATERIALS AND METHODS: One hundred twenty-nine consecutive patients with head and neck cancers treated between July 1993 and June 1994 were prospectively randomized to receive either megestrol acetate, 40 mg qid (megace group), prepulsid, 5 mg tid (cisapride group), or a placebo treatment (control group) during radiotherapy. Before radiotherapy, body weight (kg), appetite score, performance status, biochemical parameters and hematological parameters were evaluated, and the above-noted clinical and biochemical parameters were assessed and recorded every other week. All patients received 6- 10 MV X-rays or Co-60 gamma-ray to head and neck region for a full course of radiotherapy, 61.2-75.6 Gy/7-9 weeks. RESULTS: Forty-eight patients were enrolled in the megace group, 41 patients in the cisapride group, and 40 patients in the control group. At the 2nd, 4th, 6th and 8th week, as the radiation dose escalated, the megace group had significantly less body weight loss than did the cisapride and control groups (P = 0.045, 0.024, 0.006, 0.003, respectively). The appetite scores of the megace group were significantly higher than those of the cisapride and control groups (P = 0.0001). However, there were no statistically significant differences in the change of albumin level among these three groups at the 2nd, 4th, 6th and 8th week (P > 0.05, respectively). CONCLUSIONS: Megestrol acetate can significantly decrease the degree of body weight loss, and can prevent the deterioration of appetite in patients with head and neck cancers receiving radiotherapy. However, prepulsid lacks the above-mentioned clinical benefits.

Adult↗

Retinoid-X receptor (RXR) differentially augments thyroid hormone response in cell lines as a function of the response element and endogenous RXR content.

Retinoid-X receptor (RXR) forms heterodimers with thyroid hormone receptor (TR) and significantly enhances binding to thyroid hormone response elements (TREs). Expression of RXR in a transient transfection assay augments the T3 response, but the influences of the specific cell line and TRE used have not been systematically studied. We determined RXR alpha and -beta augmentation of the TR alpha-mediated T3 response in transient transfection assays of COS, JEG, and mouse embryonic stem (ES) cell lines for a series of eight wild-type thyroid hormone (T3) and retinoic acid response elements (previously shown to bind TR). RXR augmented T3-induced expression in COS and ES cells (1.5- to 4-fold greater expression with added RXR compared to TR alone), but had minimal effect on augmentation of response in JEG cells. For most elements studied there was a proportional augmentation of basal and T3-stimulated expression. TREs from rat GH and laminin-B1, however, had relatively higher levels of T3-induced expression as a result of RXR cotransfection (T3 induction ratios increased 2-fold or greater). Previous characterization of these elements demonstrates that they contain more than two hexameric binding domains, all of which can simultaneously bind TR. The influence of endogenous RXR expression in a cell line on RXR augmentation of the T3 response was determined. RXR alpha and -beta messenger RNA (mRNA) expression was quantitated by Northern blot in each cell line. COS and JEG cells expressed almost exclusively RXR alpha mRNA, although expression was almost 2-fold higher in JEG compared to COS cells (12 +/- 2.5 vs. 6.8 +/- 0.5 density units relative to actin; mean +/- SE; P < 0.05). ES cells expressed only RXR beta mRNA, but at a very low level (0.4 +/- 0.1). Nuclear extracts prepared from JEG and COS cells augmented TR binding proportional to the endogenous RXR mRNA expression, and the heterodimer band was supershifted by the addition of antibody to RXR alpha. Nuclear extracts from ES cells had no detectable TR heterodimer binding to a range of response elements. RXR augmentation of the T3 response differs among cell lines and is greater in those with reduced endogenous RXR. Furthermore, the functional augmentation of the T3 response ratio by RXR is likely to require additional sequences contained in only a subset of elements in which RXR augments TR binding.

Animals↗

Male sexual side effects associated with antidepressants: a descriptive clinical study of 32 patients.

OBJECTIVE: This is a retrospective study to add to the existing body of clinical information regarding male sexual side effects associated with antidepressants. From the chart review, thirty-four out of eighty male patients were identified to have reported loss of libido, erectile difficulty, anorgasmia, and delayed ejaculation while receiving pharmacotherapy of selective serotonin reuptake blockers (fluoxetine, paroxetine, and sertraline); tricyclic antidepressants (nortriptyline, imipramine, amitriptyline, desipramine, and clomipramine); and a monoamine oxidase inhibitor (phenelzine). METHOD: The authors also discussed the management of these sexual side effects by waiting for spontaneous remission, reducing the dosage level, and substituting the offending drug with other antidepressants. RESULTS: This article underscores the underreported nature of antidepressant-associated sexual dysfunction, the high incidence of SSRI-associated sexual side effects, equal potentials in causing sexual side effects among the three SSRI's, the low incidence rate of sexual adverse effects from bupropion, and the minimal need to add an antidote if the side effects are to be managed systematically. CONCLUSIONS: Finally, male sexual side effects can occur randomly and involve any sexual phase randomly, and the treatment approaches are similar, regardless of the types of sexual dysfunction associated with antidepressants.

Adult↗

Female sexual side effects associated with selective serotonin reuptake inhibitors: a descriptive clinical study of 33 patients.

OBJECTIVE: After the advent of selective serotonin reuptake inhibitors on the U.S. market in 1988, American psychiatrists have been faced with more choices of antidepressants for the treatment of depression. The prescribing of SSRIs has been increasing in popularity because they are easily titrated by the physicians and tolerated by patients. However, the SSRI use is frequently associated with female sexual dysfunction. The aim of this study was to describe these SSRI-associated female sexual side effects. METHODS: In a retrospective series, clinic records of 110 female SSRI-treated outpatients were reviewed for loss of or decreased libido, orgasmic disturbances (anorgasmia or delayed orgasm), as well as clinical management patterns to alleviate sexual side effects. RESULTS: Twenty-one fluoxetine-, nine paroxetine-, and five sertraline-treated cases with female sexual inhibition were identified. The fates of SSRI-associated sexual adverse effects and clinical managements of restoring these side effects were described. CONCLUSIONS: With some limitations in interpreting the data, the findings of this study suggest that SSRI-associated female sexual dysfunction occurs at a higher rate than we previously thought, equal potentials in implicating female sexual side effects among three SSRIs, and the absence or the low incidence of female sexual adverse effects from bupropion, and that these side effects can be managed by waiting for a spontaneous remission, dosage reduction of SSRIs, substitution with bupropion and other antidepressants, or the use of an antidote.

1-Naphthylamine↗

Specific restriction fragment length polymorphism in liver mitochondrial DNA of the Chinese.

By use of restriction fragment length polymorphism analysis, we examined the liver mitochondrial DNA amplified by polymerase chain reaction from 60 Chinese subjects of 31 to 78 years of age. We found nine specific mtDNA polymorphisms that had never been reported before. Eleven subjects had an Alu I polymorphic site in the subunit 2 gene of NADH dehydrogenase, five had a Hae III polymorphic site in the cytochrome oxidase subunit 2 gene, and five had a Hinf I polymorphic site in the subunit 3 gene of cytochrome oxidase. No polymorphic site was found in the structural genes coding for subunits 1, 3, 4, 4L and 6 of NADH dehydrogenase, cytochrome b, and subunit 8 of ATP synthase. Detailed analysis of the RFLP data did not show age-dependent mtDNA polymorphisms. In addition, the analysis of the restriction patterns of all the mtDNAs revealed 12 mtDNA haplotypes in all the Chinese subjects examined. Among them, type 1 mtDNA was found to be the most predominant and comprised 63.3% of the total study subjects. The restriction patterns of type 1 mtDNA generated by all restriction enzymes were identical to those deduced from the Cambridge sequence of human mtDNA. About 8.3% of the subjects exhibited type 2 mtDNA, and 5% had types 3, 5 and 8 mtDNA, respectively. Each of the rest seven mtDNA types comprised about 2% of the samples. Moreover, type 1 mtDNA was found in the platelets of three white Americans. These findings suggest that type 2 to type 12 mtDNAs have come into existence through the generation or loss of specific polymorphic restriction sites in the mtDNA of the Chinese.

Adult↗

Comparison of the regulatory regions of ilvGEDA operons from several enteric organisms.

The nucleotide sequence preceding the ilvGEDA operon has been examined and compared in five enteric organisms. The sequence in Escherichia coli B was identical to the earlier-described strain K-12 sequence. The sequences of Salmonella typhimurium and Klebsiella aerogenes were remarkably similar to that of E. coli and identical in that part of the leader region that specified the putative 32-amino-acid peptide. Thus, identical secondary structures could be postulated for the leaders of all three organisms, and regulation of operon expression could be like that postulated earlier for E. coli. Different secondary structures had to be postulated for the leader transcripts of Edwardsiella tarda and Serratia marcescens. Control of attenuation of the operon in these organisms by the level of leucyl tRNA could be explained only if ribosome stalling occurred at a single leucine codon. In both organisms, that single leucine codon is the rarely used CUA rather than the CUG that is in E. coli, S. typhimurium, and K. aerogenes.

Base Sequence↗

Leucine regulation of the ilvGEDA operon of Serratia marcescens by attenuation is modulated by a single leucine codon.

The effect of leucine limitation and of restricted leucine tRNA charging on the expression of the ilvGEDA operon of Serratia marcescens was examined. In this organism, the ilv leader region specifies a putative peptide containing only a single leucine codon that could be involved in leucine-mediated control by attenuation (E. Harms, J.-H. Hsu, C. S. Subrahmanyam, and H. E. Umbarger, J. Bacteriol. 164:207-216, 1985). A plasmid (pPU134) containing the DNA of the S. marcescens ilv control region and three of the associated structural genes was studied as a single chromosomal copy in an Escherichia coli strain auxotrophic for all three branched-chain amino acids. The S. marcescens ilv genes responded to a multivalent control similar to that found in other enteric organisms. Furthermore, the S. marcescens ilv genes were derepressed when the charging of leucine tRNA was restricted in a leuS derivative of E. coli that had been transformed with pPU134. It was concluded that ribosome stalling leading to deattenuation is not dependent on either tandem or a consecutive series of codons for the regulatory amino acid. However, the fact that the single leucine codon is a less frequently used codon (CUA) may be important. The procedure for obtaining the cloned ilv genes in single chromosomal copy exploited the dependence of ColE1 replicons on the polA gene. The cloning experiments also revealed a branched-chain amino acid-glutamate transaminase in S. marcescens that is different from transaminase B.

Codon↗