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Biomedical subjects

Y C Liu

Publications and source records attributed to Y C Liu.

At least 181 records · Page 10Linked to original sources
PubMed1996

Melioidosis: two indigenous cases in Taiwan.

We report the first two indigenously acquired cases of melioidosis in Taiwan, diagnosed by positive culture and biochemically identified using the ID 32 GN system (BioMerieux Vitek Inc, Hazelwood, MO, USA). The first patient was a 75-year-old Chinese woman who had not travelled abroad since her arrival from mainland China (San-Tung province) 47 years ago. She presented with spontaneous bacterial peritonitis and hepatitis C-related liver cirrhosis with septic shock. Burkholderia pseudomallei (formerly Pseudomonas pseudomallei) was isolated from cultures of both blood and ascites fluid. The second patient, a 70-year-old Chinese man, presented with right lower lobar pneumonia complicated with empyema and septic shock. Blood cultures grew B. pseudomallei. Both patients had underlying diabetes mellitus; one also had liver cirrhosis and chronic renal failure, while the other had a renal stone. The first patient died of refractory septic shock prior to diagnosis. The second patient survived with the use of intravenous ceftazidime for 30 days, followed by oral amoxicillin-clavulanic acid for a further 3 months. These cases serve as a reminder to clinical physicians that melioidosis is now no longer exclusive to patients with a history of travel to endemic areas. A high index of clinical suspicion is required for early diagnosis and treatment in order to reduce the mortality and improve clinical outcome.

Aged↗
PubMed1996

Group a streptococcal meningitis.

Meningitis due to group A Streptococcus is uncommon. Only a few cases have been reported in the literature. In this paper, we report a case of a 19-year-old man who presented with fever, headache, nausea, vomiting and a decrease in level of consciousness. Five days prior to admission, he had an episode of acute pharyngitis. Group A Streptococcus was isolated from both the cerebrospinal fluid and blood. He recovered without sequelae after therapy with penicillin G for 2 weeks. Physicians should be aware that group A streptococcal infection may cause meningitis.

Adult↗
PubMed1996

The suitable treatment for adenocarcinoma in situ of uterine cervix: a report of four cases.

Adenocarcinoma in situ (AIS) of the uterine cervix is a rare disease. Some authors suggested that conization is a suitable treatment for AIS as for squamous cell carcinoma in situ. However, others did not agree. Four cases of AIS, from 1984 to 1994, have been diagnosed in the Hospital of National Taiwan University. If the diagnosis of the conization specimen showed AIS, abdominal total hysterectomy was performed days thereafter. The remaining uterine cervix was checked by histopathology to determine whether it was free of cancer lesions. AIS lesions remained in the uterine cervix, as shown by conization in two cases. AIS is not like lesion as squamous cell carcinoma in situ lesion which is easy to be removed by conization. It is suggested that conization is not an adequate treatment for AIS, rather, a total hysterectomy should be performed.

Adenocarcinoma↗
PubMed1996

Hydatid cysts in the liver.

A 67-year-old Taiwanese woman with multilocular hydatid cysts of the liver presented with a 5-month history of intermittent right upper abdominal discomfort. Abdominal ultrasonography and computed tomography showed multiple cysts in both lobes of the liver. Subsequent selective celiac angiography revealed an avascular space-occupying lesion in the right lobe. She underwent a radical excision of the cyst by total closed (without opening the wall) cystopericystectomy over segments 4, 5 and 6. Histologic study of the lesions showed three structural components: 1) an outer acellular laminated membrane, 2) a thin nucleated germinal membrane and 3) several protoscolices with Echinococcus granulosus suckers. The patient has been well for 5 years since her discharge. Although hydatid cysts of the liver are extremely rare in Taiwan, they may cause life-threatening complications and mortality. Making a preoperative diagnosis is important and is only possible if this rare disease is kept in mind.

Aged↗
PubMed1996

Complete resolution of diastolic mitral regurgitation in chronic, but not acute aortic regurgitation after aortic valve replacement--a transesophageal echocardiography study.

A 65-year-old male was admitted with progressive dyspnea on exertion. Severe aortic regurgitation (AR) had been disclosed by transthoracic echocardiography 10 mon previously. Aortic valve replacement was proposed and intraoperative transesophageal echocardiography on color Doppler imaging revealed severe aortic regurgitation, moderate global hypokinesis of the left ventricle and mild-to-moderate diastolic mitral regurgitation. The regurgitant jet was seen to pass through the posterior mitral leaflet in a direction toward the center of left atrium. Mitral valve perforation was suspected. But mitral valve was found to be intact after a thorough exploration. Surgery proceeded uneventfully and diastolic mitral regurgitation was resolved completely after the aortic valve was successfully replaced. Diastolic mitral regurgitation has been reported to be closely related to acute AR, but the picture differs somewhat from the present example. The possible cause for this disease presentation is to be further investigated.

Aged↗
PubMed1995

Separation and quantitation of cytochrome c oxidase subunits by Mono-Q fast protein liquid chromatography and C18 reverse-phase high-performance liquid chromatography.

Mono-Q fast protein liquid chromatography (FPLC) combined with C18 reverse-phase HPLC was used for quantitative subunit analysis of bovine heart cytochrome c oxidase, a multisubunit membrane complex. By this approach normal cytochrome c oxidase preparations were shown to be a mixture of enzyme that has all 13 subunits and complexes that are missing 1-3 subunits. A distinct advantage of this procedure is that homogeneous 13- or 11-subunit enzyme can be easily isolated from heterogeneous cytochrome c oxidase mixtures. The method involves: (1) separation of complexes that are depleted of subunits using Mono-Q FPLC and (2) quantitative subunit analysis of the purified complexes by C18 reverse-phase HPLC with a water/acetonitrile gradient in 0.1% trifluoroacetic acid. The approach has four distinct advantages over other methods of analysis, e.g., sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) or C4 reverse-phase HPLC. (1) The reproducible yield and the baseline resolution between each eluting subunit permits quantitative determination of the subunit content with an accuracy of +/- 5%. (2) Subunits that are very difficult to separate by SDS-PAGE, e.g., subunits VIa, VIb, and VIc, are completely resolved by this system. (3) The combination of Mono-Q purification and C18 reverse-phase HPLC analysis permits an accurate assessment of both homogeneity and subunit content. (4) The quantitative nature of the reverse-phase HPLC system also makes it a powerful method for analyzing the specificity and extent of chemical modification of specific subunits as is shown by the difference in reactivity of subunit VIa toward N-iodoacetylamidoethyl-1-aminonaphthalene-5-sulfonate and 4,4'-dipyridyl disulfide.

Animals↗
PubMed1995

Inhibition of phosphatidylinositol 3-kinase activity by association with 14-3-3 proteins in T cells.

Proteins of the 14-3-3 family can associate with, and/or modulate the activity of, several protooncogene and oncogene products and, thus, are implicated in regulation of signaling pathways. We report that 14-3-3 is associated with another important transducing enzyme, phosphatidylinositol 3-kinase (PI3-K). A recombinant 14-3-3 fusion protein bound several tyrosine-phosphorylated proteins from antigen receptor-stimulated T lymphocytes. PI3-K was identified by immunoblotting and enzymatic assays as one of the 14-3-3-binding proteins in resting or activated cells. Moreover, endogenous 14-3-3 and PI3-K were coimmunoprecipitated from intact T cells. Far-Western blots of gel-purified, immunoprecipitated PI3-K with a recombinant 14-3-3 fusion protein revealed direct binding of 14-3-3 to the catalytic subunit (p110) of PI3-K. Finally, anti-phosphotyrosine immunoprecipitates from activated, 14-3-3-overexpressing cells contained lower PI3-K enzymatic activity than similar immunoprecipitates from control cells. These findings suggest that association of 14-3-3 with PI3-K in hematopoietic (and possibly other) cells regulates the enzymatic activity of PI3-K during receptor-initiated signal transduction.

14-3-3 Proteins↗
PubMed1995

Association of the "major histocompatibility complex subregion" I-J determinant with bioactive glycosylation-inhibiting factor.

Murine suppressor T-cell hybridoma cells (231F1) secrete not only bioactive glycosylation-inhibiting factor (GIF) but also an inactive peptide comparable to bioactive GIF peptide in its molecular size and reactivity with anti-GIF; the amino acid sequence of the inactive peptide is identical to that of the bioactive homologue. The inactive GIF peptide in culture supernatant of both the 231F1 cells and a stable transfectant of human GIF cDNA in the murine suppressor T hybridoma selectively bound to Affi-Gel 10, whereas bioactive GIF peptides from the same sources failed to bind to the gel. The inactive cytosolic human GIF from the stable transfectant and Escherichia coli-derived recombinant human GIF also had affinity for Affi-Gel 10. Both the bioactive murine GIF peptide from the suppressor T hybridoma and bioactive recombinant human GIF from the stable transfectant bound to the anti-I-J monoclonal antibody H6 coupled to Affi-Gel. However, bioactive hGIF produced by a stable transfectant of human GIF cDNA in BMT10 cells failed to be retained in H6-coupled Affi-Gel. These results indicate that the I-J specificity is determined by the cell source of the GIF peptide and that the I-J determinant recognized by monoclonal antibody H6 does not represent a part of the primary amino acid sequence of GIF. It appears that the epitope is generated by a posttranslational modification of the peptide.

Amino Acid Sequence↗
PubMed1995

Age-specific regulation of clotting factor IX gene expression in normal and transgenic mice.

Factor IX (FIX), a circulating serine protease that serves as an essential component of the blood coagulation pathway, has been shown to increase with age in humans. We show here that murine FIX mRNA and activity levels also increase with age. Furthermore, one form of hemophilia B, hemophilia B Leyden, which is caused by mutations within the promoter region of the FIX gene, has a distinct age-dependent phenotype. To determine the source of the age-related increases in FIX gene expression, we have analyzed the regulation of the normal FIX gene promoter and FIX Leyden gene promoter with the +13 mutation during aging by generating transgenic mice that contain the -189 to +21 bp promoter segment ligated to a chloramphenicol acetyltransferase reporter gene. We have established that the normal FIX promoter and the Leyden promoter transgenes are expressed in a tissue-specific manner in vivo. The normal FIX promoter transgene does not show any differences in the pattern of expression with age or sex of the organism, whereas the Leyden promoter transgene showed age-dependent male-specific expression. This is the first demonstration of the FIX Leyden phenotype in a transgenic mouse model.

Age Factors↗
PubMed1995

Olfactory receptor-like genes are located in the human major histocompatibility complex.

The murine major histocompatibility complex (MHC) includes sequences that are responsible for haplotype-specific odor types that, in turn, influence mating preference. We report that there are several olfactory receptor genes or pseudogenes in the Class I region of the human MHC. At least one of these genes is intact, appears to encode an mRNA, and is quite homologous to a previously reported murine olfactory receptor.

Amino Acid Sequence↗
PubMed1995

Serum response element associated transcription factors in mouse embryos: serum response factor, YY1, and PEA3 factor.

Many mammalian transcription factors, including human and mouse serum response factors (SRFs), are post-translationally modified with O-linked N-acetylglucosamine monosaccharides on multiple serine and/or threonine residues. Nuclear extracts were prepared from 9.5 to 19 days postcoitum mouse embryos and subsequently were fractionated by wheat germ agglutinin (WGA)-agarose affinity chromatography. SRF binds WGA-agarose and apparently is O-glycosylated. On the other hand, the low molecular weight serum response element (SRE)-binding proteins, including the previously named band I and band II factors, did not bind WGA-agarose. Furthermore, we showed that the fastest migrating complex contains the Yin-Yang 1 (YY1) factor. YY1 binds to the c-fos SRE and skeletal alpha-actin muscle regulatory element (MRE), but not the cardiac alpha-actin MRE. Nuclear extracts from NIH/3T3 fibroblasts contain similar, if not identical, SRE-binding complexes. Besides these SRE-binding factors, mouse PEA3-binding factor, presumably an ETS domain-containing protein, was found to bind SRF protein. This physical interaction, between SRF and ETS domain proteins, was shown to involve the DNA-binding domain-containing region of SRF and not the carboxyl-terminal transactivation domain.

Animals↗
PubMed1995

Estimation of PCNA mRNA stability in cell cycle by a serum-deprivation method.

A simple scheme was developed to study the mRNA stability of the proliferating cell nuclear antigen (PCNA) gene during cellular transition from the G1/S boundary to a quiescent state. By this scheme, CHO.K1 cells were grown to about 80% confluence and then serum-starved for 40 h for synchronization in a quiescent state. The quiescent cells were serum-stimulated for a period of time (between 8 h and 12 h) and then grown in serum-free medium until being harvested for further analyses. The cellular PCNA mRNA level was analyzed by Northern blotting. As compared with that in cells which were continuously incubated in serum-containing medium, the decline of the mRNA level, after reaching the peak, in these serum-deprived cells was virtually devoid of mRNA synthesis. Thus, this mRNA decay was taken for the measurement of mRNA stability. The advantage of the scheme is that, unlike the treatment of transcription inhibitors, it does not prevent the cells from completing the rest of the cell cycle before returning to the resting state, and so the mRNA stability observed is cell cycle dependent. In contrast with the previous report that the stability of PCNA mRNA in quiescent cells is less by severalfold than that in S phase cells, our study shows that the mRNA stability of PCNA remained constant during the cellular transition from G1/S boundary to quiescent state.

Animals↗
PubMed1995

Serum responsiveness of the rat PCNA promoter.

Expression of proliferating cell nuclear antigen (PCNA) gene is growth-regulated. The growth dependence of the rat PCNA gene promoter activity was investigated. Cultured cells were transfected with the promoter containing plasmid and recovered for 48 h in serum-free medium to become quiescent. Cells were then cultured in serum-containing medium and harvested at certain intervals after serum-stimulation, and the promoter-directed chloramphenicol acetyltransferase activities in cell extracts were measured. The promoter used in this study contained sequences between -693 and +125 in relation to the transcription initiation site. The promoter activity was found to be serum-responsive. However, the serum-responsiveness of the promoter became less obvious when the amount of the promoter increased; meanwhile, the promoter became active in the control unstimulated (or quiescent) cells. It was suspected that the dosage effect was due to the titration of the negative regulatory factor in quiescent cells. The titration experiment with a reporterless construct as competitor for regulatory factors showed that the excess of promoter molecules reduced the promoter activity in serum-stimulated cells, while causing a transiently increase of promoter activity in quiescent cells. Based on these results, it is postulated that the serum-responsiveness of the rat PCNA promoter is controlled by both negative and positive regulatory factors. Consistent with this proposition, promoter binding proteins of 105 and 114 kDa were identified only in serum-stimulated and quiescent cells, respectively, in addition to several other promoter binding proteins (ranging from 76 to 110 kDa) which were seen in both serum-stimulated and quiescent cells.

Animals↗
PubMed1995

The effect of copayments and income on the utilization of medical care by subscribers to Japan's National Health Insurance System.

This study uses cross-sectional data from Japan's 47 prefectures covering subscribers to Japan's National Health Insurance system to analyze the effects of income and copayment levels on the utilization of medical care. Multivariate regression models were run for the years 1984 and 1989, with the utilization ratio (number of health insurance claims per 100 insurance subscribers) for total, inpatient, outpatient, and dental services as the dependent variable. Independent variables included copayment per patient day, deflated per capita income, population density, percentage of subscribers over age 65, number of beds and clinics per 1,000 persons, and number of doctors and dentists per 1,000 persons. The data were then stratified according to per capita income and percentage of insurance subscribers over the age of 65 in each prefecture. The copayment amount exhibited a small, but significant negative effect on the utilization of all medical services. Utilization of outpatient care was most sensitive to the copayment rate. The per capita income stratification models revealed the greatest copayment effect on inpatient care for the lowest income group. The results of the age stratification models support popular notions about the use of hospitals by the elderly as substitutes for elderly care facilities. The effects of copayments and income vary not only among the type of medical care (inpatient, outpatient, and dental) but also among the income and age stratifications of groups in the National Health Insurance system.

Age Factors↗
PubMed1995

International nurses' experiences seeking graduate education in the United States.

Nurses from many countries in the world continue to seek further education in the U.S. every year. This study examined their experiences (N = 83) and those of the host institutions (N = 35) in the U.S. regarding the difficulties each experienced in coping with unfamiliar curricula and cultural mores, as well as financial constraints.

Adaptation, Psychological↗
PubMed1995

[Effects of poria cocos on ototoxicity induced by kanamycin in guinea-pigs].

In order to prevent the ototoxicity of kanamycin (KM), the effects of Poria Cocos (PC) on the ototoxicity induced by KM in guinea-pigs was observed by infusing the PC decoction into the guinea-pigs with comparing the difference in the general intoxicating symptom, prayer's reflex (PR) threshold, brainstem auditory evoked potentials (BAEPs) and the absence rate of outer hair cells in the first turn of cochlea. The results suggested that the ototoxicity of KM was retarded by giving the PC decoction. On 7th day after given KM, PR threshold of 4,6,8 kHz in the medicated group and control group were 4.7 +/- 1.5 dB, 5.7 +/- 2.4 dB, 2.7 +/- 1.2 dB and 10.5 +/- 3.2 dB, 12.1 +/- 3.7 dB, 8.5 +/- 2.7 dB respectively. BAEPs threshold on 13th day given KM raised 22.7 +/- 9.7 dB in the medicated group and 51.3 +/- 14.4 dB in control group. The absence rate of outer hair cells in first turn of cochlea were 39.4% and 67.4% respectively. The results suggested that PC might be antagonistic to the ototoxicity of KM in guinea-pigs.

Animals↗
PubMed1995

Streptococcal toxic shock syndrome in southern Taiwan.

This report outlines our experience with streptococcal toxic shock syndrome (STSS) at the Veterans General Hospital-Kaohsiung during the period October 1990 to November 1993. Group A streptococci were isolated from blood or normally sterile tissue in association with hypotension and multi-organ failure in the eight cases studied. A primary focus of infection was identified in seven cases, including pneumonia (1), septic arthritis (1) and soft-tissue infections (5). The remaining patient suffered from hyperglycemic hyperosmolar non-ketotic coma and Group A streptococcal bacteremia, without an obvious focus of infection. There were four cases of bacteremia. Clinical complications included acute renal failure in all eight cases, disseminated intravascular coagulation in five cases, liver involvement in two cases, adult respiratory distress syndrome in one case and soft-tissue necrosis in five cases. All isolates were sensitive to penicillin, and most patients were treated with intravenous penicillin G, with or without other antibiotics (gentamicin or clindamycin). Of the six patients with soft-tissue infection, two underwent amputation of the infected limb, and one patient underwent sono-guided pigtail drainage of psoas muscle abscess. Three of the patients died. STSS may be uncommon in Taiwan, but it is not rare. Early recognition of STSS (facilitated by Gram stain and culture), prompt debridement and drainage, and adequate antibiotic treatment with penicillin or clindamycin, or both, are necessary for control of such lethal infections.

Adult↗