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Biomedical subjects

Y H Lin

Publications and source records attributed to Y H Lin.

At least 55 records · Page 3Linked to original sources
PubMed2000

Heparin reduces the alpha-helical content of cobra basic phospholipase A(2) and promotes its complex formation.

The interaction of phospholipase A(2) (PLA(2)) with glycosaminoglycans (GAGs) has recently attracted attention in view of its implication on inflammation and cell proliferation. By using Fourier Transformed Infrared (FTIR) spectroscopic measurements, we demonstrate here that binding of cobra basic phospholipase A(2) from Naja nigricollis (N-PLA(2)) to heparin may induce a significant conformational change observed in the amide I region of the enzyme's alpha-helical and beta-sheet structure. It is observed that notable conformational change of N-PLA(2) due to heparin binding occurs only when heparin's chain length is at least an octasaccharide as evidenced by circular dichroism and optical density measurements. This correlation may be an important factor in the aggregation of N-PLA(2) and N-PLA(2)-heparin complexes. Heparin induced change in conformation of PLA(2) is suggested to be a notable link in understanding the diversity in PLA(2) activity when rendered to the extracellular matrix of cell membranes that is full of GAG molecules.

Animals↗
PubMed2000

Detection of TT virus DNA in patients with liver disease and recipients of liver transplant.

TT virus (TTV) is transfusion-transmissible but its involvement in post-transfusion hepatitis is uncertain. To investigate the potential association of TTV with liver diseases, the prevalence of TTV DNA was tested by semi-nested PCR in 113 carriers of hepatitis C virus (HCV), 10 patients with acute liver failure, 11 patients with cryptogenic cirrhosis and 200 control blood donors. Thirty-seven of these patients underwent liver transplantation and were tested pre- and post-transplantation. TTV DNA was semi-quantified in serial samples from seven patients with unexplained post-transplant hepatitis. TTV genotyping was performed on samples from 28 patients by sequence analysis. The prevalence of TTV DNA in blood donors was 1.5% and 17% in HCV infected haemophiliacs. In patients with acute or chronic liver disease or hepatitis, 6 to 27% prevalence was observed. After liver transplantation, the prevalence of TTV DNA increased from 16 to 46% (P < 0.01). In patients who developed unexplained hepatitis post-transplantation, TTV viraemia did not parallel ALT levels. TTV DNA either increased in titre or became detectable shortly after transplantation, suggesting that either TTV was transfusion-transmitted, or, more likely, that immunosuppression caused a recurrence of low level or undetectable TTV viraemia. TTV had considerable genomic diversity in the N22 region, corresponding to at least 4 genotypes. Genotype 2 was found in 14/28 patients.

Adult↗
PubMed2000

Purification and characterization of a luxO promoter binding protein LuxT from Vibrio harveyi.

Bioluminescence in the marine bacterium Vibrio harveyi is cell density dependent and is regulated by small molecules (autoinducers) excreted by the bacteria. The autoinducer signals are relayed to a central regulator, LuxO, which acts in its phosphorylated form as a repressor of the lux operon at the early stages of cell growth. We report in these studies the purification to homogeneity of a luxO DNA binding protein (LuxT) from V. harveyi after five major chromatography steps, including a highly effective DNA affinity chromatography step and reverse-phase HPLC. Regeneration of binding activity was accomplished after HPLC and SDS-PAGE by renaturation of LuxT from guanidine hydrochloride. It was also demonstrated that the functional LuxT was a dimer of 17 kDa that bound tightly (K(d) = 2 nM) to the luxO promoter. The sequences of three tryptic peptides obtained on digestion of the purified protein did not match any sequences in the Protein Data Bank, indicating that LuxT is a new V. harveyi lux regulatory protein.

Bacterial Proteins↗
PubMed2000

Alcohol consumption and breast cancer among black and white women in North Carolina (United States).

OBJECTIVE: The purpose of this study was to investigate the effects of alcohol consumption on breast cancer risk in black and white women. METHODS: We used data from the Carolina Breast Cancer Study, a population-based, case-control study of black and white women in North Carolina. Interviews were conducted with 890 cases and 841 controls frequency-matched on age and race. RESULTS: Overall, the prevalence of moderate to high levels of alcohol consumption was low. Compared with abstainers, the multivariate odds ratio for recent intake of one or two drinks per day was 1.4 (95% CI = 0.9-2.1) and two or more drinks a day was 1.0 (95% CI = 0.6-1.6); increasing consumption was not associated with risk (p for trend = 0.6). The associations were similar, but somewhat weaker, for average lifetime consumption. Among women who consumed 91 g/week or more of alcohol, a nonsignificant increased risk of breast cancer was observed for women reporting binge drinking (OR = 1.5; 95% CI = 0.9-2.3), but not for those who consumed less than 91 g/week reporting binge drinking (OR = 1.0; 95% CI = 0.6-1.5). Odds ratios did not differ meaningfully by race, age, menopausal status, exogenous hormone use, or body mass index. CONCLUSIONS: These data provide little evidence for an association between alcohol consumption and risk of breast cancer among either black or white women.

Adult↗
PubMed2000

In vitro maturation and fertilization of immature oocytes: a comparative study of fertilization techniques.

PURPOSE: Our purpose was to investigate the factors influencing maturation and fertilization of immature oocytes. METHODS: Immature oocytes were obtained from women undergoing cesarean section. They were cultured in the maturation medium either with or without cumulus cells. After maturation to metaphase II, they were randomly fertilized by in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). RESULTS: After incubation for 48 hr, 441 oocytes (42.8%) reached metaphase II. Among them, 56.6% of cumulus-enclosed oocytes, but only 29.2% of denuded oocytes, reached metaphase II. Of the 289 cumulus-enclosed oocytes, the fertilization rates by IVF and ICSI were 56.3 and 84.1%, respectively (P < 0.01). Of the 152 denuded oocytes, the fertilization rates by IVF and ICSI were 39.5 and 84.5%, respectively (P < 0.01). The cleavage rates, however, were similar. CONCLUSIONS: Cumulus cells are beneficial in the maturation of human oocytes in vitro and that ICSI increases the fertilization rate for the in vitro matured oocytes. The developmental potential of the fertilized oocytes, however, is similar irrespective of the fertilization method or the presence or absence of cumulus cells.

Adult↗
PubMed2000

Control of bioluminescence in Vibrio fischeri by the LuxO signal response regulator.

Bioluminescence in the marine bacterium Vibrio fischeri is controlled by the excretion of a N-acyl homoserine lactone (HSL) autoinducer which interacts with a regulator, LuxR, and activates transcription of the lux operon at high-cell density. This system has become the prototype for quorum sensing in many bacteria. Although light emission in Vibrio harveyi is also regulated by a N-acyl-HSL inducer, in sharp contrast, a completely different and more complex system is involved in quorum sensing which is mediated via LuxO, the response regulator of a phosphorelay signal transduction system. In the present work, luxO and the overlapping luxU gene, also involved in the phosphorelay system in V. harveyi, have been discovered in V. fischeri. By gene replacement technology, a V. fischeri luxO- mutant was generated whose phenotype was similar to that of V. harveyi luxO- showing that LuxO is involved in control of luminescence in V. fischeri. This mutant could be complemented with luxO from either V. fischeri or V. harveyi resulting in the restoration of the dependence of luminescence intensity on cell density. In contrast to V. harveyi luxO-, light emission of V. fischeri luxO- was stimulated by the N-acyl-HSL autoinducer indicating that luxO is part of a second signal transduction system controlling luminescence in this species. The presence of a luxO-based phosphorelay regulatory system as well as the luxR-based system in V. fischeri suggests that the former system, originally discovered in V. harveyi, may be a general regulatory mechanism in luminescent bacteria.

Amino Acid Sequence↗
PubMed2000

Gonococcal meningitis and intra-abdominal abscess in the presence of a ventriculoperitoneal shunt.

We report a case of gonococcal meningitis with an intraabdominal abscess in a 19-y-old woman, who had a ventriculoperitoneal shunt after craniotomy for astrocytoma. Percutaneous drainage was performed for the intraabdominal abscess. Ceftriaxone was administered with the ventriculoperitoneal shunt removal. The clinical course improved, but visual impairment last for 3 months following treatment.

Abdominal Abscess↗
PubMed2000

Simultaneous determination of sweeteners and preservatives in preserved fruits by micellar electrokinetic capillary chromatography.

A micellar electrokinetic capillary method for the simultaneous determination of the sweeteners dulcin, aspartame, saccharin, and acesulfame-K and the preservatives sorbic acid; benzoic acid; sodium dehydroacetate; and methyl-, ethyl-, propyl-, isopropyl-, butyl-, and isobutyl-p-hydroxybenzoate in preserved fruits is developed. These additives are ion-paired and extracted using sonication followed by solid-phase extraction from the sample. Separation is achieved using a 57-cm fused-silica capillary with a buffer comprised of 0.05 M sodium deoxycholate, 0.02 M borate-phosphate buffer (pH 8.6), and 5% acetonitrile, and the wavelength for detection is 214 nm. The average recovery rate for all sweeteners and preservatives is approximately 90% with good reproducibility, and the detection limits range from 10 to 25 microg/g. Fifty preserved fruit samples are analyzed for the content of sweeteners and preservatives. The sweeteners found in 28 samples was aspartame (0.17-11.59 g/kg) or saccharin (0.09-5.64 g/kg). Benzoic acid (0.02-1.72 g/kg) and sorbic acid (0.27-1.15 g/kg) were found as preservatives in 29 samples.

Acetonitriles↗
PubMed2000

Treatment of deltoid contracture in adults by distal release of the deltoid.

Twenty-five consecutive adult patients (32 shoulders) with deltoid contracture were treated with distal release and followed up for an average of 4 years (range, 2-8 years). All shoulders achieved full range of motion and complete relief of pain and deformity after 3 months. No muscle weakness was clinically evident. In addition, another five adult patients (nine shoulders) with deltoid contracture were treated with distal release and quantitative measurement of muscle power recovery around the shoulder with Cybex 340 dynamometer before surgery, and 3 months and 1 year after surgery. Isokinetic peak torque of shoulder muscles did not decrease significantly at either 60 degrees per second or 180 degrees per second angular velocity after surgery. In addition, the shoulder extensors showed a twofold increase of isokinetic peak torque after surgical release of deltoid contracture. Distal release was a simple and effective surgical technique to treat deltoid contracture in adults. All patients in this series achieved a satisfactory outcome.

Adult↗
PubMed2000

Identification of a major cluster of Klebsiella pneumoniae isolates from patients with liver abscess in Taiwan.

Klebsiella pneumoniae has emerged as the leading liver abscess pathogen in Taiwan, with the percentage rising from 30% in the 1980s to over 80% in the 1990s. Most of the patients with K. pneumoniae liver abscess are diabetic and without biliary tract disease. Some patients develop serious extrahepatic complications such as endophthalmitis, meningitis, lung abscess, and necrotizing fasciitis. Pulsed-field gel electrophoresis (PFGE) was used for cluster analysis of 96 isolates from patients with liver abscess and 60 isolates from patients with other diseases. A total of 136 PFGE types were identified. Among the 96 liver abscess-associated isolates, 60 (62.5%) were classified in major cluster A. Cluster A included 41 PFGE types (types 1 to 41) which had a genetic similarity of at least 72.4% +/- 9.4%. The PFGE patterns of cluster A strains are so similar that they could have originated from the same ancestor. This study demonstrates that cluster A plays an important role in the high incidence of K. pneumoniae liver abscess in Taiwan.

Cluster Analysis↗
PubMed2000

Coupling of osteopontin and its cell surface receptor CD44 to the cell survival response elicited by interleukin-3 or granulocyte-macrophage colony-stimulating factor.

The receptors for interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) share a common beta subunit, the distal cytoplasmic domain of which is essential for the promotion of cell survival by these two cytokines. Genes whose expression is specifically induced by signaling through the distal cytoplasmic domain of this receptor beta subunit were screened by a subtraction cloning approach in derivatives of a mouse pro-B-cell line. One gene thus identified was shown to encode a protein highly homologous (with only 7 amino acid substitutions) to murine osteopontin (OPN), a secreted adhesion protein. Conditioned medium from cells expressing wild-type OPN, but not that from cells expressing a deletion mutant lacking residues 79 to 140, increased the viability of a non-OPN-producing cell line in the presence of human GM-CSF. Antibody blocking experiments revealed that OPN produced as a result of IL-3 or GM-CSF signaling was secreted into the medium and, through binding to its cell surface receptor, CD44, contributed to the survival-promoting activities of these two cytokines. Furthermore, coupling of the OPN-CD44 pathway to the survival response to IL-3 was also demonstrated in primary IL-3-dependent mouse bone marrow cells. These results thus show that induction of an extracellular adhesion protein and consequent activation of its cell surface receptor are important for the antiapoptotic activities of IL-3 and GM-CSF.

Animals↗
PubMed2000

The hepatoprotective effects of Solanum alatum Moench. on acetaminophen-induced hepatotoxicity in mice.

Solanum alatum Moench. has been shown to have a protective effect against carbon tetrachloride (CCl4)-induced liver injury. Solanum alatum treatment (100 mg/kg, p.o.) decreased the elevation of serum alanine aminotransferase (ALT; GPT) and aspartate aminotransferase (AST; GOT) induced by acetaminophen (paracetamol) (600 mg/kg, i.p.) administration. It also decreased the extent of visible necrosis in liver tissue. In addition, Solanum alatum treatment restored hepatic glutathione (GSH) depletion induced by acetaminophen (600 mg/kg, i.p.) administration. Microsomal enzyme levels such as P-450, reductase, and aniline hydroxylation enzyme were also restored to normal levels after Solanum alatum administration. The hepatoprotective mechanism may function through direct binding with acetaminophen toxic metabolites, decreasing the attraction of acetaminophen metabolites for other cellular GSH or thiol protein. Additionally, Solanum alatum treatment increased the concentration of hepatic GSH and maintained a high level activity of GSTase, which led to acceleration of the excretion of toxic acetaminophen metabolites.

Acetaminophen↗
PubMed2000

Hepatoprotective effects of Arctium lappa on carbon tetrachloride- and acetaminophen-induced liver damage.

The root of Arctium lappa Linne (A. lappa) (Compositae), a perennial herb, has been cultivated for a long time as a popular vegetable. In order to investigate the hepatoprotective effects of A. lappa, male ICR mice were injected with carbon tetrachloride (CCl4, 32 microl/kg, i.p.) or acetaminophen (600 mg/kg, i.p.). A. lappa suppressed the SGOT and SGPT elevations induced by CCl4 or acetaminophen in a dose-dependent manner and alleviated the severity of liver damage based on histopathological observations. In an attempt to elucidate the possible mechanism(s) of this hepatoprotective effect, glutathione (GSH), cytochrome P-450 (P-450) and malondialdehyde (MDA) contents were studied. A. lappa reversed the decrease in GSH and P-450 induced by CCl4 and acetaminophen. It was also found that A. lappa decreased the malondialdehyde (MDA) content in CCl4 or acetaminophen-intoxicated mice. From these results, it was suggested that A. lappa could protect the liver cells from CCl4 or acetaminophen-induced liver damages, perhaps by its antioxidative effect on hepatocytes, hence eliminating the deleterious effects of toxic metabolites from CCl4 or acetaminophen.

Acetaminophen↗
PubMed2000

Radix Angelica Sinensis extracts ameliorate scopolamine- and cycloheximide-induced amnesia, but not p-chloroamphetamine-induced amnesia in rats.

The effects of the methanolic extract of Radix Angelica Sinensis (Umbellifera) (abbreviated as RAS extract) and n-hexane fraction of RAS extract (RAS(H) fraction) on the various drugs-induced amnesia in rats were studied by using passive avoidance task. RAS extract (1 g/kg) significantly prolonged the shortened step-through latency induced by SCOP and CXM, but not PCA. Furthermore, RAS(H) fraction (1 g/kg) also significantly prolonged the shortened step-through latency induced by SCOP and CXM but not PCA. RAS extract at any dose alone did not influence the step-through latency in the training trial produced by non-shocked rats, but it plus PCA prolonged the latency compared with PCA alone. However, RAS(H) fraction (1 g/kg) prolonged the latency in the training trial produced by non-shocked rats, but it plus any induced drugs did not differ from any induced drugs alone. These results suggest that the attenuating effects of RAS extract on the various drugs-induced amnesia were related to the memory processes. n-Hexane fraction of RAS extract might be one of the active fractions of RAS extract in the treatment of amnesia.

Amnesia↗
PubMed2000

Objective comparison of shoulder dysfunction after three neck dissection techniques.

A prospective study with subjective evaluation of shoulder pain and objective evaluation of shoulder muscle strength by isokinetic testing and electromyographic and electroneurographic studies of spinal accessory nerve function was performed on patients who had undergone neck dissection procedures. Twenty-one patients with head and neck cancer were enrolled in this study. Three types of neck dissection were performed: 7 selective neck dissections, 9 modified radical neck dissections, and 5 radical neck dissections. All patients who underwent radical neck dissection had shoulder pain, and 80% of them had shoulder droop after the operation. In the patients who underwent selective neck dissection, the electromyographic findings of the spinal accessory nerve were relatively normal. Their shoulder strength was sometimes decreased at I month after operation, but it had returned to preoperative strength by the 6-month follow-up visit. These findings suggested that patients who underwent selective neck dissection had the least damage to spinal accessory nerve function and the least shoulder disability after neck dissection.

Adult↗
PubMed2000

Combined spinal-epidural anesthesia for cesarean section in a patient with Takayasu's disease.

We describe a successful episode of anesthesia management in a parturient affected with Takayasu's disease who underwent elective cesarean section under combined spinal-epidural anesthesia. Takayasu's disease is characterized by chronic occlusive inflammation of the arteries (panarteritis) of unknown origin that usually involves the aorta and its main branches. Progression of the disease may be marked by aneurysmal dilation of the affected arteries and may lead to a fatal outcome, usually from cerebral ischemia or heart failure. The impact of pregnancy on Takayasu's disease is unclear, but worsening of ischemic symptoms, cardiac failure, aggravation of hypertension and cerebral hemorrhage have been reported in sufferers who are in the later stages of pregnancy. Nonetheless, anesthesia management of a parturient with advanced Takayasu's disease presents a challenge to anesthetists.

Adult↗
PubMed2000

Distribution of CAG repeat size in the dentatorubral and pallidoluysian atrophy (DRPLA) gene in a normal population in Taiwan.

Dentatorubral and pallidoluysian atrophy (DRPLA) is an autosomal dominant neurodegenerative disorder with expansion of trinucleotide CAG repeats in the coding region of the gene. Expansion of the repeat tract beyond the normal range produces gene products with extended polyglutamine tracts. In this study, we analyzed the distribution of the CAG repeats in the DRPLA alleles in a normal Taiwanese population. We observed 15 different alleles and found that the range of the CAG repeat number was from 7-21. The most frequent allele contained 15 CAG repeats that represented 20% of the total analyzed alleles, followed by the 17 repeats (15.8%). The heterozygosity rate of this locus was 88%. Twelve parents-to-children transmissions of the DRPLA alleles in a Machado-Joseph disease family appeared to be normal without any alteration of the CAG repeat numbers. Phenotypes of DRPLA overlapped those of autosomal dominant cerebellar ataxia (ADCA). In order to identify DRPLA patients in Taiwan, we screened six autosomal dominant cerebellar ataxia patients without expansion in known spinocerebellar ataxia genes. All six patients had the repeat numbers within the normal range; thus, the possibility of DRPLA could be excluded.

Alleles↗