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Biomedical subjects

Y H Lin

Publications and source records attributed to Y H Lin.

At least 73 records · Page 4Linked to original sources
PubMed2000

A complex containing both trypsin inhibitor and dehydroascorbate reductase activities isolated from mitochondria of etiolated mung bean (Vigna radiata L. (Wilczek) cv. Tainan no. 5) seedlings.

A complex containing trypsin inhibitor (TI) activity was extracted with 0.1 M TRIS buffer (pH 7.9) from trypsin-treated mitochondria of etiolated mung bean seedlings, and further purified with a Superdex 200 FPLC column. This partially purified complex with an M(r) about 820 kDa exhibited additional dehydroascorbate (DHA) reductase activity with specific activities of 0.21, 1.53 and 1.54 mumol ascorbate formed min-1 mg-1 protein at pH 6.0, 6.5 and 7.0, respectively, when glutathione was added. Much lower DHA reductase activity (0.013 and 0.026 mumol ascorbate formed min-1 mg-1 protein at pH 6.5 and 7.0, respectively) was found when glutathione was omitted. The isolated complex gave positive results when it was tested by TI activity staining after SDS-PAGE, and could be recognized by a polyclonal antibody which was raised against 38 kDa sweet potato Kunitz-type TI, one of the root storage proteins of sweet potato. The possible physiological functions of this complex with both TI and DHA reductase activities were discussed.

Chromatography↗
PubMed2000

Transesophageal echocardiographic monitoring for transcatheter closure of atrial septal defect.

BACKGROUND AND PURPOSE: Transcatheter closure of atrial septal defect (ASD) is generally performed under fluoroscopy alone. Recently, we have used transesophageal echocardiography (TEE) monitoring as an aid in performing this procedure. The purpose of this study was to evaluate the efficacy and complications associated with this use of TEE. METHODS: Transcatheter closure of ASD was accomplished under TEE guidance simultaneously with fluoroscopic imaging in 11 patients aged 3 to 33 years (weight, 15.4-62.9 kg). TEE was successfully performed in all patients after endotracheal general anesthesia. The ASDs were reexamined before catheterization. The appropriate placement of the occluder device was evaluated. RESULTS: Seven cases were uneventful with successful ASD occluder implantation, but one failed because of a large ASD (24.7 mm). In three cases, transcatheter closure was aborted after TEE examination, one with a large ASD (27.05 mm), one with an ASD that was too small, and one with multiple fenestrated ASDs. CONCLUSIONS: Routine TEE monitoring for transcatheter closure of ASDs is effective for evaluation of ASD before implantation of an occluder, to ensure the proper seating of the occluder after the defect occlusion is complete.

Adolescent↗
PubMed1999

TT virus is present in a high frequency of Italian hemophilic patients transfused with plasma-derived clotting factor concentrates.

The prevalence of the blood-borne TT virus (TTV) in Italian hemophiliacs treated with different preparations of factor VIII was determined. Of the 178 hemophilic patients (mean age, 29 years), TTV-DNA was found in 123 (69%), in comparison to 22 of 100 (22%) blood donors (P <.0001). Of the 123 patients who tested positive for TTV, significant numbers were also infected with human hepatitis viruses and/or human immunodeficiency virus (HIV): 31% had TTV and hepatitis C virus (HCV), 22% had TTV, and at least 2 of the 4 known human blood-borne viruses tested, whereas 15% had TTV alone. The risk of acquiring TTV alone was only slightly higher in recipients of unmodified plasma factor concentrates (78%, odds ratio, 1.24; 95% confidence interval [CI], 0.27 to 5.79) than in patients treated with virus inactivated concentrates (67%), whereas the risk was significantly lower in recipients of recombinant factors (11%, odds ratio, 0.09; 95% CI, 0.01 to 0.52). Serum alanine aminotransferase (ALT) levels were elevated in 2 of 27 patients (7%) with TTV alone compared with 43 of 56 patients (77%) coinfected with TTV and HCV and compared with 16 of 21 patients (76%) with HCV alone. Taken together, these results indicate that TTV frequently infects Italian hemophiliacs treated with plasma-derived factor VIII concentrates, both unmodified and virus-inactivated. Our results do not suggest a causal effect of TTV on chronic liver disease in these patients.

Adolescent↗
PubMed1999

Heparin binding to cobra basic phospholipase A2 depends on heparin chain length and amino acid specificity.

Heparin is shown to bind specifically to the carboxy-terminal region of toxic type I phospholipase A2 from Naja nigricollis (N-PLA2) by competition assay using synthetic polypeptides and heparin affinity chromatography. The binding strength is seen to depend on heparin chain length and the presence of N-sulfate groups of heparin. It is observed that both electrostatic and non-electrostatic interactions are involved in the specific binding of heparin to the carboxy-terminus. When heparin's size is at least a decasaccharide, about two molecules of N-PLA2 bind to one molecule of heparin, as evidenced by the chemical estimate of protein to carbohydrate ratio in such N-PLA2/heparin complexes. Based on such a stoichiometric measurement and computer modeling of the N-PLA2/heparin complex, it is suggested that the binding sites of the two N-PLA2 molecules on one heparin molecule lie on the opposite sides of the heparin chain.

Amino Acid Sequence↗
PubMed1999

A prospective study on TT virus infection in transfusion-dependent patients with beta-thalassemia.

A novel DNA virus designated TT virus (TTV) has been reported to be involved in the development of posttransfusion non-A-C hepatitis. We evaluated the frequency and natural course of TTV infection in a cohort of transfusion-dependent thalassemic patients in a 3-year follow-up study. Ninety-three serum hepatitis C virus (HCV) antibody-negative patients (median age of 8 years; range, 0 to 25) from eight centers were studied. Of them, 34 (37%) had an abnormal alanine-aminotransferase (ALT) baseline pattern, and the other 12 (13%) showed ALT flare-ups during the follow-up. TTV DNA in patient sera collected at the time of enrollment and at the end of follow-up was determined by polymerase chain reaction (PCR). In parallel, serum samples from 100 healthy blood donors were also tested. At baseline, 87 patient sera (93.5%) tested positive for the TTV DNA. Of these TTV DNA-positive patients, 84 (96.5%) remained viremic at the end of the study period. Of the 6 TTV DNA-negative patients, 3 acquired TTV infection during follow-up. However, no definite relation was observed between the results of TTV DNA determination and ALT patterns. TTV viremia was also detectable in 22% of blood donors. In conclusion, TTV infection is frequent and persistent among Italian transfusion-dependent patients. The high rate of viremia observed in healthy donors indicates that the parenteral route is not the only mode of TTV spread.

Adolescent↗
PubMed1999

Detection of protease activities using specific aminoacyl or peptidyl p-nitroanilides after sodium dodecyl sulfate - polyacrylamide gel electrophoresis and its applications.

A general method for detecting protease activities on acrylamide or agarose gels after sodium dodecyl sulfate - polyacrylamide gel electrophoresis (SDS-PAGE) using specific aminoacyl p-nitroanilide (NA) or peptidyl NA as substrate is described. This method is extended from the spectrophotometric assay of p-nitroaniline, which is a chromogenic product liberated by protease action on aminoacyl NA or peptidyl NA. The acrylamide gel containing protein bands was dipped directly into a solution which contained specific synthetic aminoacyl NA or peptidyl NA as a substrate or had been overlaid with an agarose gel containing the same substrate. The p-nitroaniline released on the acrylamide or agarose gel by the specific protease was diazotized with sodium nitrite and then coupled to N-(1-naphthyl)-ethylenediamine to produce distinct activity band(s). The substrates used for protease activity staining on gels were identical to those used for spectrophotometric assays. Some applications are described.

Benzoylarginine Nitroanilide↗
PubMed1999

Influence of histologic type and age on survival rates for invasive cervical carcinoma in Taiwan.

OBJECTIVE: The aim of this study was to assess survival rates and to evaluate histologic type and age as prognostic factors for cervical carcinoma in an ethnically homogenous population in Taiwan. METHODS: A retrospective analysis was conducted of 3678 cases of squamous cell carcinoma and adenocarcinoma that were diagnosed and treated for invasive cervical carcinoma between 1977 and 1994. Observed survival rates were estimated using the Kaplan-Meier method, and prognostic factors were assessed using Cox's proportional hazards regression analysis. RESULTS: Correlating both FIGO stage and age with histologic type revealed a higher proportion of cases with adenocarcinoma in the lower FIGO stages (P = 0.0417). Further, we found that the younger the age group the higher the proportion of cases of cervical adenocarcinoma (P = 0.0006). The 5-year survival rate was lower for patients with adenocarcinoma than for patients with squamous cell carcinoma (66.5 vs 74.0%, P = 0.0009). The 5-year survival rates for FIGO stages I, II, III, and IV squamous cell carcinoma were 81.3, 75.2, 42.7, and 26.1%, respectively, while for adenocarcinoma they were 75.9, 62.9, 29.2, and 0%, respectively. The difference in survival rates between squamous cell carcinoma and adenocarcinoma was found mainly in stage I (P = 0.0039) and stage II (P = 0.0103), where radiotherapy was used as the primary treatment. Age also affected the overall Kaplan-Meier estimate of survival. The younger the age group, the better the survival rate (P < 0.0001). Multivariate analysis confirmed a highly significant association between survival rate and both histologic type (P < 0.0001) and age (P = 0.0037). CONCLUSIONS: Early stage cervical cancer (stages I and II) with a glandular component had a lower 5-year survival rate than squamous cell carcinoma in cases where radiotherapy was the primary treatment. We speculate that this difference in survival rates between cervical adenocarcinoma and squamous cell carcinoma was due to the relative ineffectiveness of radiotherapy as a primary treatment in cases of adenocarcinoma.

Adenocarcinoma↗
PubMed1999

Ultrasonic backscattering from porcine whole blood of varying hematocrit and shear rate under pulsatile flow.

It was shown previously that ultrasonic scattering from whole blood varies during a flow cycle under pulsatile flow both in vitro and in vivo. It has been postulated that this cyclic variation may be associated with the dynamics of red cell aggregation because the shearing force acting on the red cell aggregates across the lumen is a function of time during a flow cycle. In all studies, the local shear rate variation as a function of time is unknown. The effect of shear rate on the red cell aggregation and, thus, on ultrasonic scattering from blood can only be merely speculated. One solution to this problem is to estimate the shear rate in a flow conduit by finite element analysis (FEA). An FEA computational fluid dynamics (CFD) tool was used to calculate local shear rate in a series of experiments in which ultrasonic backscattering from porcine whole blood under pulsatile flow was measured as a function of hematocrit and shear rate intravascularly with a 10-MHz catheter-mounted transducer in a mock flow loop. The results show that, at 20 beats per min (BPM), the magnitudes of the cyclic variation for hematocrits at 30, 40, and 50% were approximately 4 dB. However, at 60 BPM, the magnitude of cyclic variation was found to be minimal. The results also confirm previous findings that the amplitude and the timing of the peak of ultrasonic backscattering from porcine whole blood under pulsatile flow during a flow cycle are dependent upon the shear rate and hematocrit in a complicated way.

Animals↗
PubMed1999

A novel nociceptor signaling pathway revealed in protein kinase C epsilon mutant mice.

There is great interest in discovering new targets for pain therapy since current methods of analgesia are often only partially successful. Although protein kinase C (PKC) enhances nociceptor function, it is not known which PKC isozymes contribute. Here, we show that epinephrine-induced mechanical and thermal hyperalgesia and acetic acid-associated hyperalgesia are markedly attenuated in PKCepsilon mutant mice, but baseline nociceptive thresholds are normal. Moreover, epinephrine-, carrageenan-, and nerve growth factor- (NGF-) induced hyperalgesia in normal rats, and epinephrine-induced enhancement of tetrodotoxin-resistant Na+ current (TTX-R I(Na)) in cultured rat dorsal root ganglion (DRG) neurons, are inhibited by a PKCepsilon-selective inhibitor peptide. Our findings indicate that PKCepsilon regulates nociceptor function and suggest that PKCepsilon inhibitors could prove useful in the treatment of pain.

Acetic Acid↗
PubMed1999

Dioscorin, the major tuber storage protein of yam (Dioscorea batatas decne) with carbonic anhydrase and trypsin inhibitor activities.

Dioscorin, the tuber storage protein of yam (Dioscorea batatas Decne), was purified successively by ammonium sulfate fractionation, DE-52 ion exchange chromatography, and Sephadex G-75 column. Two protein bands (82 and 28 kDa) were found under nonreducing conditions after SDS-PAGE; but only one band (32 kDa) was detected under reducing conditions. The first 21 amino acids in the N-terminal region of the 28 kDa form were VEDEFSYIEGNPNGPENWGNL, which was highly homologous to deductive sequence of dioscorin from cDNA of another yam species (Dioscoreacayenensis Lam) reported by Conlan et al. (Plant Mol. Biol. 1995, 28, 369-380). Hewett-Emmett and Tashian (Mol. Phylogenet. Evol. 1996, 5, 50 -77) mentioned that, according to DNA alignments, dioscorin from yam (D. cayenensis) was alpha-carbonic anhydrase (alpha-CA) related. In this report, we found that the purified dioscorin showed both CA dehydration activity using sodium bicarbonate as a substrate and CA activity staining after SDS-PAGE. A polyclonal antibody, which was raised against trypsin inhibitor (TI), a storage protein of sweet potato (Ipomoea batatas [L.] Lam var. Tainong 57), cross-reacted with dioscorin, which also showed TI activity determined by both activity staining after SDS-PAGE and trypsin inhibition determination.

Amino Acid Sequence↗
PubMed1999

Loss of heterozygosity and microsatellite instability in hepatocellular carcinoma in Taiwan.

Elucidation of the basic genetic changes of human hepatocellular carcinoma is important for the understanding and treatment of this cancer. We used microsatellite polymorphism markers to study 30 cases of hepatocellular carcinoma (34 tumours) on all human chromosomes. DNA from 34 pairs of hepatocellular carcinomas and corresponding non-tumour parts was prepared. Loss of heterozygosity (LOH) and microsatellite instability on 23 chromosomes were investigated by 231 sets of microsatellite markers. More than 20% LOH was shown for loci on 16q (47.1%), 13q (32.4%), 17p (32.4%), 5q (26.5%), 11p (23.5%) and 9p (20.6%). The commonly affected regions were mapped to 16q12.1, 16q12.2, 16q24, 13q12.1-32, 17p13, 5q32, 5q34, 5q3, 11p15, 11q23-24 and 9p21. Hepatitis B virus carriers had a significantly higher frequency of LOH on chromosomes 5q, 11p and 16q. Furthermore, larger tumour size tended to have higher frequency of LOH at D16S409 locus (16q12.1). Microsatellte instability was only found in 12 of 231 markers and the frequency is very low. These data suggest that the chromosomes 16q, 13q, 17p, 5q, 11p and 9p might participate in hepatocarcinogenesis. However, microsatellite instability might play little role in the development of this cancer in Taiwan.

Adult↗
PubMed1999

Prevention of hypotension after spinal anesthesia for cesarean section: dextran 40 versus lactated Ringer's solution.

BACKGROUND: This study was designed to compare the efficacy of 10% dextran 40 with lactated Ringer's (LR) solution in reducing the incidence and severity of hypotension after spinal anesthesia for Cesarean section. METHODS: Sixty ASA grade I patients scheduled for Cesarean section were randomized into two groups in a double-blind fashion to receive either 500 ml of dextran 40 or 1000 ml of LR solution prior to induction of spinal anesthesia. RESULTS: The incidence of hypotension was 16 in 30 (53.3%) in the LR solution group and 8 in 30 (26.7%) in the dextran group (P < 0.05). The required dose of ephedrine for treatment of hypotension was significantly greater in the LR solution group than in the dextran group (15.5 mg versus 3.2 mg, P < 0.05). Neonatal outcome, as determined by Apgar score, was good and similar in both groups. CONCLUSIONS: We concluded that 500 ml of dextran 40 is more effective than 1000 ml of lactated Ringer's solution in reducing the incidence of hypotension induced by spinal anesthesia.

Adult↗
PubMed1999

Percutaneous epididymal sperm aspiration in psychogenic anejaculation during IVF. A report of two cases.

BACKGROUND: Psychogenic anejaculation on the day of oocyte retrieval is uncommon in in vitro fertilization (IVF) programs. Before the use of intracytoplasmic sperm injection (ICSI), either the cycle had to be canceled or a sperm donor recruited. CASES: Two couples were enrolled for IVF. On the day of oocyte retrieval, the male partners developed psychogenic anejaculation. CONCLUSION: In cases of psychogenic anejaculation during IVF, percutaneous epididymal sperm aspiration can be utilized to obtain sperm for ICSI.

Adult↗
PubMed1999

Pyogenic psoas abscess: analysis of 27 cases.

From 1993 to 1998, 29 pyogenic psoas abscesses occurring in 27 patients were seen in Taichung Veterans General Hospital. Their age range was 25 to 85 years. Diabetes mellitus was the leading underlying disease. Fever and pain in the flank area, back and hip were the usual manifestations. The duration of symptoms prior to the diagnosis ranged from 3 days to 6 months. Most abscesses were diagnosed by computed tomography (CT) images and proven by abscess cultures, which were divided into primary and secondary types. Eighteen of 29 abscesses were regarded as primary. Staphylococcus aureus was the most common pathogen in the primary abscesses, followed by Streptococcus agalactiae, Escherichia coli, viridans streptococci, S. epidermidis, and Salmonella spp.. In the secondary abscess category, E. coli was the leading organism in this series, followed by S. aureus, Klebsiella pneumoniae, viridans streptococci and Candida albicans. The associated conditions included epidural abscess, osteomyelitis, septic arthritis, perirenal abscess, pulmonary tuberculosis, empyema, hydronephrosis and trauma history. The initial empiric therapy comprised mostly of cefazolin or oxacillin with or without an aminoglycoside. Thirteen patients underwent percutaneous drainage, while six received surgical debridement, including two with a recurrent abscess. One patient had both drainage and debridement. Others received medical treatment only. Two of the patients with primary abscess died in spite of percutaneous drainage. Therefore, open drainage, besides appropriate antibiotic treatment, is still required to control complex abscesses with sepsis.

Adult↗
PubMed1999

Antimicrobial susceptibility of clinical isolates of enterococci.

To describe antimicrobial resistance patterns of Enterococcus spp., we measured minimal inhibitory concentrations (MICs) of five antimicrobial agents for 174 clinical isolates of enterococci collected in Taichung Veterans General Hospital from November, 1996 to January, 1998. Major sources included blood (48), the genitourinary tract (39), soft tissue and wounds (28), and the gynecological tract (16). The sensitivity test of vancomycin was performed using the broth microdilution method. The susceptibility of ampicillin, penicillin, gentamicin, and teicoplanin was tested by the agar dilution method. The MIC90 of penicillin, ampicillin, gentamicin, teicoplanin and vancomycin were 2, 1, > 2,048, 0.125 and 2 microg/mL, respectively. Ampicillin-resistant isolates represented only 4.6% of all enterococci tested. These results reveal that vancomycin-resistant enterococci were found in 1.7% of all enterococci isolates in this study. However, all isolates were sensitive to teicoplanin.

Adult↗
PubMed1998

Activity staining on polyacrylamide gels of trypsin inhibitors from leaves of sweet potato (Ipomoea batatas L. Lam) varieties.

The failure of activity staining of trypsin inhibitors in crude leaf extracts of sweet potato varieties including Tainong 27, Tainong 34, and Tainong 57 on a 15% sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) gel was prevented by dipping the gels in solutions containing 10-40 mM hydrogen peroxide, 10 mM Tris buffer (pH 7.9) for 30 min before staining.

Acrylic Resins↗
PubMed1998

Activity staining of pectinesterase on polyacrylamide gels after acidic or sodium dodecyl sulfate electrophoresis.

Pectinesterase (PE), from commercial orange peels or ammonium sulfate fractionation (50-80% saturation) of pea pods, was detected on polyacrylamide gels after native acidic polyacrylamide gel electrophoresis (PAGE) or sodium dodecyl sulfate (SDS)-PAGE by using the synthetic substrate beta-naphthyl acetate (beta-NA). The release of beta-naphthol (at 322 nm) from beta-NA was proportional to PE activity. The PE activity bands on polyacrylamide gels after native acidic PAGE or SDS-PAGE were stained with a combination of tetrazotized o-dianisidine and beta-NA. This fast and sensitive method can be used for enzyme purification and characterization.

Acrylic Resins↗