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Biomedical subjects

Y H Lin

Publications and source records attributed to Y H Lin.

161 records · Page 9Linked to original sources
PubMed1982

Involvement of glyoxysomal lipase in the hydrolysis of storage triacylglycerols in the cotyledons of soybean seedlings.

The total cotyledon extract of soybean (Glycine max [L.] Merr. var. Coker 136) seedlings underwent lipolysis as measured by the release of fatty acids. The highest lipolytic activity occurred at pH 9. This lipolytic activity was absent in the dry seeds and increased after germination concomitant with the decrease in total lipids. Using spherosomes (lipid bodies) isolated from the cotyledons during the peak stage of lipolysis (5-7 days) as substrates, about 40% of the lipase activity was found in the glyoxysomes after organelle breakage had been accounted for; the remaining activity was distributed among other subcellular fractions but none was found in the spherosomal fraction. The glyoxysomal lipase had maximal activity at pH 9, and catalyzed the hydrolysis of tri-, di-, and monoacylglycerols of linoleic acid, the most abundant fatty acid in soybean. The spherosomes contained a neutral lipase that could hydrolyze monolinolein and N-methylindoxylmyristate, but not trilinolein. This spherosomal lipase activity dropped off rapidly during early seedling growth, preceding lipolysis. Spherosomes isolated from either dry or germinated seeds did not possess lipolytic activity, and spherosomes from germinated seeds but not from dry seeds could serve as substrates for the glyoxysomal lipase. It is concluded that the glyoxysomal lipase is the enzyme catalyzing the initial hydrolysis of storage triacylglycerols.

Journal Article↗
PubMedDate not supplied

Pathology of chronic hepatitis B virus infection in children: with special reference to the intrahepatic expression of hepatitis B virus antigens.

The clinical, virologic and pathologic features of chronic hepatitis B virus infection were studied in 66 children, of whom 29 were symptomatic and 37 asymptomatic. The majority (79%) of symptomatic children had histologically aggressive diseases: 11 had chronic active hepatitis and 10 had cirrhosis. In contrast, most asymptomatic children had nonaggressive diseases (35 cases); only 2 had chronic active hepatitis. Nine of the 10 children with cirrhosis were under 6 years of age, and the cirrhosis was often advanced, indicating that hepatitis B virus infection can cause the rapid development of cirrhosis in early life. HBcAg was present in 71% of 62 cases examined and correlated well with the status of HBeAg in serum. Cytoplasmic HBcAg was more frequently associated with aggressive disease than was nuclear HBcAg expression alone or no detectable HBcAg in the liver. A male predominance (75%) was found, particularly in children with aggressive diseases (91%) compared to those with nonaggressive forms of disease (67%). Sera from mothers of 43 of these children were tested for HBsAg, and 51% were positive. HBsAg was particularly common among mothers of children with symptomatic disease (69%) or cirrhosis (100%). These findings suggest that male sex and perinatal infection are important factors in the development of overt chronic hepatitis B and cirrhosis in children.

Adolescent↗
PubMedDate not supplied

Comparison of polymerase chain reaction and pulsed-field gel electrophoresis for the epidemiological typing of Campylobacter jejuni.

Seventeen sporadic Campylobacter jejuni enteritis cases occurred in Taichung City, Taiwan between July 1995 and September 1995. Pulsed-field gel electrophoresis (PFGE) and enterobacterial repetitive intergenic consensus (ERIC-1) primed polymerase chain reaction (PCR) techniques were compared for the epidemiological typing of the 17 C. jejuni isolates. Fourteen distinct PFGE fingerprint patterns were observed. Fifteen distinct PCR fingerprint patterns were demonstrated. Two clusters of isolates (isolates 5 and 6; isolates 10, 11 respectively) were found to be genetically indistinguishable by both methods. In conclusion, we consider that PFGE is a highly reproducible method for determining the relatedness among the C. jejuni isolates in this study, although their limited numbers of restriction fragments may reduce the discriminatory power. Although less reproducible than PFGE typing, ERIC-1 primed PCR can be used as a simple and rapid tool to discriminate different strains of C. jejuni.

Campylobacter Infections↗
PubMedDate not supplied

Characterization and quantitation of extracellular collagen matrix in myocardium of pigs with spontaneously occurring hypertrophic cardiomyopathy.

The extracellular matrix between cardiocytes has been suggested to play an important role in maintaining the structure and function of the heart. The purpose of this study was to elucidate the morphological changes in the collagen of the extracellular matrix (ECM) in the hearts of pigs with hypertrophic cardiomyopathy. Sixty pigs diagnosed with hypertrophic cardiomyopathy from 605 purebred Landrace pigs ages 6 to 9 months were used in this study. Morphologically, these pigs with hypertrophic cardiomyopathy had increased heart weight and heart-to-body weight ratio, thickening of the left ventricular (LV) and right ventricular (RV) free walls and septum, disorientation of cardiocytes, myocardial fibrosis, and intramural coronary arteriosclerosis. Similar observations have been described in our preliminary report (Cardiovasc Pathol 3:261, 1994). In the present study, we have modified the silver impregnation technique to stain paraffin-embedded sections to demonstrate three types of ECM. There were endomysial struts, perimysial weaves, and epimysial coils in the myocardium. The light microscopic findings of the struts, weaves, and coils were also confirmed by scanning electromicroscopic examination. The numbers of these fine structures were increased significantly in the pigs with hypertrophic cardiomyopathy. In addition, the amounts of collagen in the LVs, RVs, and septum (Sep) in pigs with hypertrophic cardiomyopathy (LV = 19.37+/-0.79, RV = 23.72+/-0.72, Sep = 20.38+/-0.94 microg/mg, n = 60) were significantly higher (p < 0.01) than that in similar areas of normal pigs (LV = 14.56+/-1.11, RV = 18.90+/-1.02, Sep = 14.99+/-1.33 microg/mg, n = 30, respectively). Our findings of an overall increase of collagen content suggested that the accumulation of collagen matrix might be another factor responsible for the diastolic dysfunction of hypertrophic cardiomyopathy. These results might also infer that the increased collagen matrix could contribute to the stiffness of the cardiac chambers, thereby markedly affecting systolic and diastolic function of the heart. These observations provide further support that the pig may be an animal model for human cardiovascular disease.

Animals↗
PubMedDate not supplied

Metabolic flux variation of Saccharomyces cerevisiae cultivated in a multistage continuous stirred tank reactor fermentation environment.

The technique of metabolic flux analysis was implemented to elucidate the flux balancing of Saccharomyces cerevisiae cultivated in a multistage continuous stirred tank reactor fermentation environment. The results showed that the majority of the substrate (97.70 +/- 0.49%) was funneled into the glycolytic pathway, while the remainder was subdivided between the pentose phosphate pathway and pathways for polysaccharide synthesis. At the pyruvate node, 87.30 +/- 1.38% of the flux was channeled through the reaction governed by pyruvate decarboxylase. Fluxes through the pyruvate dehydrogenase bypass were maintained at a constant level (82.65 +/- 1.47%) irrespective of the configuration of the fermentation setup. Activity through the TCA "cycle" was replenished by the reaction catalyzed by pyruvate carboxylase and by the transport of cytosolic oxaloacetate across the mitochondrial membrane. The CO(2) evolution rate varied as fermentation progressed; however, the yield coefficient of CO(2) remained at a constant value. Although a constant yield of ethanol (0.42 g of ethanol/g of glucose) was obtained, operations of the TCA cycle were gradually switched from partially reductive to partially oxidative pathways from the first fermenter to the fourth fermenter.

Alcoholic Beverages↗
PubMedDate not supplied

Studies on microencapsulation of 5-fluorouracil with poly(ortho ester) polymers.

Microencapsulation of 5-fluorouracil was successfully accomplished with poly(ortho ester) polymers by the emulsification-solvent evaporation method. While actual drug loading increased with increasing drug load (5-15% w/w), the entrapment efficiency remained essentially unaffected, under a given set of experimental conditions. Incorporation of sorbitan sesquioleate enhanced entrapment efficiency, decreased the volume-surface mean diameter of the poly(ortho ester) microspheres and provided controlled release of 5-fluorouracil. The volume of the aqueous phase was more important than the concentration of polyvinyl alcohol in it. The entrapment efficiency improved from 13 to 33% when the volume of the aqueous phase was increased from 20 to 80 ml. The volume of organic phase (methylene chloride) and the concentration of polymer in it played an important role. The use of smaller volumes of more concentrated polymer solution enhanced actual drug loading, entrapment efficiency and produced larger microspheres. The release studies conducted in 0.01 M phosphate buffer at 37+/-1.0 degrees C demonstrated that the release of 5-FU from the microspheres prepared with sorbitan sequioleate was nearly independent of the initial drug load with a mean zero-order rate constant of 0.0063% per hour. The data suggested that drug release was largely a diffusional process with contributions from dissolution and polymer degradation.

Antimetabolites, Antineoplastic↗
PubMedDate not supplied

Effects of naturally occurring glucosides, solasodine glucosides, ginsenosides and parishin derivatives on multidrug resistance of lymphoma cells and leukocyte functions.

Solamargine, solasonine, ginsenosides and parishin-related compounds were investigated for their effects on mdr efflux pump of lymphoma cells, and their effects on T cell proliferative assays and cell mediated immune functions, antibody-dependent cellular cytotoxicity (ADCC) and natural killer (NK) cell activity of human peripheral mononuclear cells. Solamargine and solasonine were the only drugs which inhibited all of the tested immune functions; however, ginsenoside Rc and Rd enhanced T cell proliferative assays and marginally increased the NK cell activity. The majority of the compounds were not able to reverse the multidrug resistance of mouse lymphoma cells. However, ginsenosides Rc, Rd and parishin C were able to moderately reduce the activity of the efflux pump. Parishin, parishin C and crude extract significantly enhanced the ADCC reaction.

Animals↗
PubMedDate not supplied

Tuberous sclerosis with cardiac rhabdomyoma manifested by fetal bradycardia: report of a case.

This is a case of neonatal tuberous sclerosis associated with cardiac rhabdomyoma and manifested by fetal cardiac arrhythmia-bradycardia. The prenatal echocardiography showed multiple cardiac tumors which occupied the left and right ventricles. The largest one measured 5.2 cm in diameter. It was found to be 4.5 x 4.1 x 3.5 cm in size at autopsy. A postnatal cranial echogram showed multiple subependymal nodules. The patient expired after 7 hours of life. The autopsy findings confirmed the diagnosis. The mother of the patient had adenoma seb'aceum on the face and an ungual fibroma on the left little finger. Cranial computerized tomography revealed a small calcified tubercle.

Adult↗
PubMedDate not supplied

Primary ovarian cancer at National Taiwan University Hospital: 1980-1989.

BACKGROUND: Ovarian cancer is a silent killer. Most of the patients came with advanced stages. The retrospective review here was for a better understanding of the current situation of ovarian cancer patients treated at National Taiwan University Hospital. METHODS: One hundred and eighty-seven patients with primary ovarian cancer were treated at National Taiwan University Hospital from 1980 to 1989. Medical records were reviewed thoroughly. The WHO histological classification and FIGO staging system (1987) were used. RESULTS: The ages at diagnosis ranged from 2 to 87 years. Peak incidence was noted between 50-59 years. According to the WHO histological classification, the distribution of histological types included 79.1% epithelial, 4.3% sex-cord stromal tumors, 0.5% lipid cell, 12.8% germ cell, and 3.2% non-specific soft tissue origin. Based on FIGO staging system, 31.6% of the patients were in stage I, 11.2% in stage II, 40.6% in stage III and 16.6% in stage IV. Mean ages for common epithelial, non-epithelial, and germ cell ovarian cancers were 49, 26, 23 years, respectively. Cytoreductive surgery was done in 47.4% of stage I, 23.8% of stage II, 15.8% of stage III, and 12.9% of stage IV. The leading treatment modality was surgery plus chemotherapy, which was performed in 50.3% of whole series. Survival in patients with ovarian cancer is a function of clinical stage and histologic type. The 5-year observed survival rates for stage I to IV were 76.3%, 59.9%, 9.1%, and 4.3% respectively. The 5-year survival rate was 29.4% for epithelial ovarian cancer, 51.4% for non-epithelial ovarian cancer, and 64.5% for germ cell tumors. CONCLUSIONS: The prognosis and survival rate are still unsatisfactory despite the various modalities of treatment. Further improvements need the development of methods for early detection and multiple modalities of therapy.

Adolescent↗