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Biomedical subjects

T Y Lin

Publications and source records attributed to T Y Lin.

At least 145 records · Page 8Linked to original sources
PubMed1994

Application of criteria identifying febrile outpatient neonates at low risk for bacterial infections.

A total of 254 previously healthy outpatient neonates 31 days of age or younger with a rectal temperature > or = 38 degrees C were enrolled in a prospective study during an 18-month period to evaluate the validity of applying low risk criteria for bacterial infections in this population. All of the neonates received standard physical examinations and laboratory evaluations including blood and urine cultures at the time of admission. Those who had no evidence of ear, eye, soft tissue, umbilical or skeletal infection had between 5000 and 15,000 white blood cells/mm3, had a C-reactive protein of less than 20 mg/liter or an erythrocyte sedimentation rate less than 30 mm/hour and a normal urinalysis were considered at low risk for bacterial infections. Bacterial infections were confirmed by cultures of the various body fluids. Bacterial infections were present in 17.7% (45 neonates) and bacteremia or meningitis in 5.1% (13 neonates). Eight (6.0%) of the 134 neonates who met the criteria had bacterial infections, while only 1 (0.7%) had bacteremia and meningitis, compared with 37 (30.8%) and 12 (10.0%), respectively, of the 120 who did not meet the criteria (both P < 0.05). The negative predictive value of meeting the low risk criteria were 94.0% for excluding all bacterial infections and 99.3% for bacteremia and meningitis respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteremia↗
PubMed1994

Scanning microphotometry image analysis of Ha-ras-transformed human breast epithelial cells.

Nuclei of the human breast epithelial cells, MCF-10A, transfected with the c-Ha-ras oncogene, the ras proto-oncogene and the plasmid Homer 6 only, were studied by image analysis after Feulgen staining. This material had been previously used to demonstrate that the experimental insertion of the activated c-Ha-ras oncogene into the DNA of the MCF-10A cells induces their tumoural properties. The ras-transformed nuclei of the MCF-10A cells exhibited differences in chromatin supraorganization in comparison with the nuclei of human breast carcinoma MCF-7 cells, or c-Ha-ras-transformed NIH/3T3 cells and, to a much lesser extent, with those of other MCF-10A transfectants and the non-transfected MCF-10A cells. All MCF-10A transfectants exhibited unravelling of both condensed and non-condensed chromatin, which, however, was less drastic in the ras-transformed MCF-10A cells. It is hypothesized that simultaneous to a general chromatin loosening as a response to foreign transfected DNA, a reverse mechanism may be elicited by ras transformation in the chromatin of the MCF-10A cells. The result in terms of elicited chromatin condensation was not as strong as that promoted in ras-transformed NIH/3T3 cells. Considering that early steps of tumour progression in vitro have previously been assumed to be involved in the ras-transformed MCF-10A cells, the differences in chromatin supraorganization of the ras-transformed MCF-10A cells as compared with MCF-7 cells are probably due to their different tumoural stages plus the putative effect of the transfected DNA vector on the transfected MCF-10A cells.

Breast Neoplasms↗
PubMed1994

Congenital biliary tract dilatation in infancy and childhood--74 cases experience.

This report presented a twelve-year experience from 1981 to 1992. Seventy-four cases of congenital biliary tract dilatation were at diagnosed an age of 6 days to 16 years. Twenty-two cases were infants. There were 54 females and 20 males. The ratio of female to male was 2.7:1. The classic triad of abdominal pain, jaundice and a palpable mass was seen in eleven cases (14.9%). Most children suffered from abdominal pain (50/74), vomiting (45/74), anorexia (42/74) and jaundice (34/74). Prolonged jaundice was the main symptom in infancy (15/22). A long common pancreatico-biliary channel was seen in six cases (6/47); the bile amylase level was elevated in five cases (5/20), one patient had a complex union with obstructive jaundice. All these cases were diagnosed by preoperative sonography accurately (100%). According to the Todani's classification, type Ia was the most common (40/74), followed by type IV-A (25/74) and type Ic (8/74). Cholelithiasis (13/74), perforation (9/74), and atresia/stenosis of distal choledochus (8/74) were the most common associated conditions. Cyst excision with biliary tract reconstruction was performed in all cases. Reoperation was needed in ten cases. Two cases died postoperatively due to sepsis and cholangitis induced hepatic failure.

Adolescent↗
PubMed1994

Immunohistochemical visualization of fibrin in anterior chamber angle after YAG laser capsulotomy.

Hematoxylin and eosin staining of rabbit eyes after YAG laser anterior capsulotomy showed amorphous substances at the anterior chamber angle. The amorphous substances were identified as fibrin by immunohistochemical methods. This finding indicated that the obstruction of aqueous humor flow by fibrin could be responsible for the elevation of intraocular pressure following YAG laser anterior capsulotomy.

Animals↗
PubMed1993

A point mutation in the chloroplast rps12 gene from Nicotiana plumbaginifolia confers streptomycin resistance.

In an effort to understand the mechanism of streptomycin resistance in Nicotiana plumbaginifolia, we have sequenced the chloroplast rps12 gene, a potential molecular target. We report that a streptomycin-resistant mutant isolated from protoplast cultures of N. plumbaginifolia contains an A-to-G transition at nucleotide position 149 in exon 2 of the chloroplast rps12 gene. The detected point mutation predicts a substitution of arginine for lysine in a phylogenetically conserved region.

Amino Acid Sequence↗
PubMed1993

Laurence-Moon-Biedl syndrome: report of two cases.

The Laurence-Moon-Biedl syndrome is characterized by features of familial occurrence, retinitis pigmentosa, obesity, polydactyly, hypogenitalism and mental retardation. Recently, several reports have suggested renal abnormalities as an additional cardinal feature of the syndrome. We present two cases of this syndrome from two different families. The first case was an obese eight-year-old girl with poor vision and signs of mental retardation beginning at four months of age. An intravenous urogram showed dilatation of the minor calyces of both kidneys. Genital agenesis and typical retinitis pigmentosa on fundal examination all supported the diagnosis of Laurence-Moon-Biedl syndrome. The patient's father and grandmother also had symptoms of poor vision, mental retardation and obesity. The second case was an obese 14-year-old girl with blurred vision and severe mental retardation noticed at two to three months of age. Fundi showed typical retinitis pigmentosa. She also had genital agenesis but no significant family history.

Adolescent↗
PubMed1993

Acute septic arthritis of the hip in children--clinical analyses of 31 cases.

This is a retrospective study of 31 cases of acute septic arthritis of the hip in children treated at Chang Gung Memorial Hospital from 1983 to 1989. The average follow-up period was 35 months. Among them, there were 18 males (58%) and 13 females (42%). None were involved bilaterally. Fifteen cases (48%) were below 5 years of age. All cases met the diagnostic criteria including bacteriological results, clinical and radiographic changes. Limited range of motion, fever, and tenderness were the most common symptoms and signs. More than half of the patients (52%) had a leukocyte count of over 15,000/cmm. The erythrocyte sedimentation rate was elevated in 30 cases (97%). Pathogens had been isolated from blood, arthrocentesis fluid, or surgical specimens in 26 cases (84%). Staphylococcus aureus was the most common causative organism (58%). Twenty-seven cases (87%) underwent emergency arthrotomy and debridement. Five (19%) of them received unsatisfactory results. A delay in definite treatment, very young infants, and the association with osteomyelitis of the adjacent bone were the important factors associated with poor prognosis. Four cases (13%) who received only medical treatment showed satisfactory results. Early diagnosis and significant response to antibiotics contributed to this favorable outcome.

Acute Disease↗
PubMed1993

AccuMeter noninstrumented quantitative assay of high-density lipoprotein in whole blood.

A novel noninstrumented technology (ChemTrak AccuMeter) for the quantitative measurement of analytes in biological fluids was reported at the 1990 Oak Ridge Conference (Clin Chem 1990;36:1591-7). This instrument-free technology has been adapted for the quantitative measurement of high-density lipoprotein (HDL). An in situ lipoprotein separation method has been developed and incorporated into the test for HDL determination. The sensitivity of the assay system has been adjusted so that HDL is measured over a clinically significant range of 250 to 1000 mg/L. This compares to a range of 1000 to 4000 mg/L for the total cholesterol in the earlier reported assay. Like the AccuMeter total cholesterol test, the Accumeter HDL test system is self-contained and consolidates blood separation, lipoprotein separation, and specimen measurement into a single step. The test procedure is simple, and the results are accurate.

Blood Chemical Analysis↗
PubMed1993

Extrapulmonary tuberculosis in children.

Extrapulmonary tuberculosis is not a rare infection of children in Taiwan. From 1985 to 1989, we studied 39 children with the diagnosis of extrapulmonary tuberculosis from a total of 43 sites. They were diagnosed by routine diagnostic tests including bacteriologic cultures in 11, pathological features in 25, and clinical presentations in 2 patients. Positive mycobacterial DNA probe method was obtained from a patient with tuberculous meningitis. The most common sites of involvement were lymph nodes in 9 (20.9%), meninges in 7 (16.3%), bone in 7 (16.3%), joint in 6 (14.0%) and miliary infection in 6 (14.0%). The median age of the 2 patients with renal tuberculosis was 14.5 years, which was older compared to the patients with other organ systems involvement. Tuberculin skin tests were significantly positive (> 10 mm) in 54% of the tested children. Among the treated patients, 76% were cured after 9 to 12 months of antituberculous chemotherapy without sequelae, while 24% had sequelae associated with tuberculous infection despite treatment. There was no death reported during the study period. We conclude that extrapulmonary tuberculosis remains an important health problem to the pediatric population of this island despite the overall decline in the incidence of tuberculosis. Early detection and thorough treatment for a suitable period are mandatory to improve the prognosis of this potentially curable infectious disease.

Adolescent↗
PubMed1992

Construction and expression of nonsense suppressor tRNAs which function in plant cells.

An Arabidopsis thaliana L. DNA containing the tRNA(TrpUGG) gene was isolated and altered to encode the amber suppressor tRNA(TrpUAG) or the ochre suppressor tRNA(TrpUAA). These DNAs were electroporated into carrot protoplasts and tRNA expression was demonstrated by the translational suppression of amber and ochre nonsense mutations in the chloramphenicol acetyltransferase (CAT) reporter gene. DNAs encoding tRNA(TrpUAG) and tRNA(TrpUAA) nonsense suppressor tRNAs caused suppression of their cognate nonsense codons in CAT mRNAs, with the tRNA(TrpUAG) gene exhibiting the greater suppression under optimal conditions for expression of CAT. The development of these translational suppressors which function in plant cells facilitates the study of plant tRNA gene expression and will make possible the manipulation of plant protein structure and function.

Anticodon↗
PubMed1992

Smooth-pursuit eye tracking in first-episode psychotic patients and their relatives.

We wished to determine the specificity of smooth-pursuit eye tracking dysfunction to schizophrenia and the prevalences of dysfunction among functionally psychotic and normal individuals. Therefore, we investigated pursuit tracking in a large sample of psychotic patients, normal subjects, and first-degree relatives (N = 482). Patients were recruited as part of an epidemiological study of first-episode psychosis that used a broadly based referral network to identify all cases in a major metropolitan area over a 2 1/2-year period. Patients received diagnoses of schizophrenia, schizophreniform disorder, psychotic mood disorder, and paranoid or other psychotic disorder based on the third edition of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1980). The distribution of tracking performance was bimodal for the schizophrenic patients and their relatives, perhaps reflecting major gene action. Moreover, poor tracking ran in families. Pursuit tracking dysfunction was relatively specific to schizophrenic patients and their relatives and occurred infrequently in other psychotic patients and normal subjects.

Acute Disease↗
PubMed1991

Evaluating the effects of a single amino acid substitution on both the native and denatured states of a protein.

For proteins that contain a disulfide bond, stability is linked thermodynamically to thiol-disulfide exchange. We use this relationship to obtain unfolding free energies for both the reduced and oxidized forms of Escherichia coli thioredoxin from measurements of the effective concentrations of protein thiols. We then evaluate the effect of an amino acid substitution on disulfide bond formation in both the native and denatured states of the protein. Although the Pro-34----Ser substitution in thioredoxin results in a decrease of the effective concentration of protein thiols in the native state, the effective concentration increases in the denatured state. The net effect of the amino acid substitution is to increase the stability of reduced thioredoxin by approximately 2.4 kcal/mol, whereas the stability of the oxidized protein remains the same. By assuming a two-state unfolding equilibrium and a mutation free energy of -7.7 kcal/mol for the Pro-34----Ser substitution in the reduced, urea-unfolded state (based on estimates of solvation and entropic changes), we obtained relative free energies for the native and denatured states of the mutant and wild-type proteins, in both the reduced and oxidized forms.

Amino Acid Sequence↗
PubMed1991

Refined X-ray crystal structures of the reactive site modified ovomucoid inhibitor third domains from silver pheasant (OMSVP3*) and from Japanese quail (OMJPQ3*).

Tetragonal and triclinic crystals of two ovomucoid inhibitor third domains from silver pheasant and Japanese quail, modified at their reactive site bonds Met18-Glu19 (OMSVP3*) and Lys18-Asp19 (OMJPQ3*), respectively, were obtained. Their molecular and crystal structures were solved using X-ray data to 2.5 A and 1.55 A by means of Patterson search methods using truncated models of the intact (virgin) inhibitors as search models. Both structures were crystallographically refined to R-values of 0.185 and 0.192, respectively, applying an energy restraint reciprocal space refinement procedure. Both modified inhibitors show large deviations from the intact derivatives only in the proteinase binding loops (Pro14 to Arg21) and in the amino-terminal segments (Leu1 to Val6). In the modified inhibitors the residues immediately adjacent to the cleavage site (in particular P2, P1, P1') are mobile and able to adapt to varying crystal environments. The charged end-groups, i.e. Met18 COO- and Glu19 NH3+ in OMSVP3*, and Lys18 COO- and Asp19 NH3+ in OMJPQ3*, do not form ion pairs with one another. The hydrogen bond connecting the side-chains of Thr17 and Glu19 (i.e. residues on either side of the scissile peptide bond) in OMSVP3 is broken in the modified form, and the hydrogen-bond interactions observed in the intact molecules between the Asn33 side-chain and the carbonyl groups of loop residues P2 and P1' are absent or weak in the modified inhibitors. The reactive site cleavage, however, has little effect on specific interactions within the protein scaffold such as the side-chain hydrogen bond between Asp27 and Tyr31 or the side-chain stacking of Tyr20 and Pro22. The conformational differences in the amino-terminal segment Leu1 to Val6 are explained by their ability to move freely, either to associate with segments of symmetry-related molecules under formation of a four-stranded beta-barrel (OMSVP3* and OMJPQ3) or to bind to surrounding molecules. Together with the results given in the accompanying paper, these findings probably explain why Khyd of small protein inhibitors of serine proteinases is generally found to be so small.

Amino Acid Sequence↗
PubMed1991

Dominant and recessive mutations define functional domains of Toll, a transmembrane protein required for dorsal-ventral polarity in the Drosophila embryo.

The asymmetry of the dorsal-ventral pattern of the Drosophila embryo appears to depend on the ventral activation of the transmembrane Toll protein. The Toll protein is found around the entire dorsal-ventral circumference of the embryo, and it appears to act as a receptor for a ventral, extracellular signal and to then relay that signal to the cytoplasm in ventral regions of the embryo. Three of five recessive loss-of-function alleles of Toll are caused by point mutations in the region of the cytoplasmic domain of Toll that is similar to the mammalian interleukin-1 receptor, supporting the hypothesis that Toll acts as a signal-transducing receptor. Nine dominant gain-of-function alleles that cause Toll to be active in dorsal, as well as ventral, regions of the embryo are caused by mutations in the extracellular domain. Three of the dominant alleles appear to cause the protein to be constitutively active and are caused by cysteine-to-tyrosine changes immediately outside the transmembrane domain. All six of the remaining dominant alleles require the presence of a wild-type transmembrane Toll protein for their ventralizing effect and all encode truncated proteins that lack the transmembrane and cytoplasmic domains.

Alleles↗
PubMed1991

Inactivation of human fibroblast collagenase by chloroacetyl N-hydroxypeptide derivatives.

When human fibroblast collagenase was incubated with ClCH2CO-(N-OH)Leu-Ala-Gly-NH2 (2-5 mM) in Tris buffer, pH 7.4 at 25 degrees C, a slow, time-dependent inhibition of the enzyme was observed. Dialysis against a buffer to remove free inhibitor did not reactivate the enzyme. A reversible competitive inhibitor, phthaloyl-GlyP-Ile-Trp-NHBzl (50 microM) partially protected the enzyme from inactivation by the compound. From the concentration dependent rates of inactivation Ki = 0.5 +/- 0.1 mM and k3, the rate constant for inactivation = 3.4 +/- 0.3 x 10(-3) min-1 were determined. The inactivation followed the pH optimum (6.5-7.0) for the enzyme activity, suggesting direct involvement of the same active site residue(s). The reaction mode of the inhibitor may be analogous to that of the inactivation of Pseudomonas aeruginosa elastase [Nishino, N. and Powers, J. (1980) J. Biol. Chem., 255, 3482] in which the catalytic glutamate carboxyl was alkylated by the inhibitor after its binding to enzyme through the hydroxamic Zn2+ ligand. All carboxyl groups in the inactivated collagenase were modified with 0.1 M ethyl dimethylaminopropyl carbodiimide/0.5 M glycinamide in 4 M guanidine at pH 5. The inactivator-affected carboxyl group was then regenerated with 1 M imidazole at pH 8.9, 37 degrees C for 12 h and the protein was radiolabeled with 3H-glycine methyl ester and carbodiimide to incorporate 0.9 residue glycine per mol enzyme.

Amino Acid Sequence↗