Vancomycin-resistant Enterococcus durans.
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Cross Infection↗
Biomedical subjects
H Y Chen
Publications and source records attributed to H Y Chen.
pHi controls cytoplasmic calcium in rat parotid cells.
The goal of this investigation was to determine if cytoplasmic pH (pHi) modulated the basal level of the concentration of calcium ions in the cytoplasm (Cai) in rat parotid cells. We investigated the effects of various experimental manipulations on both pHi and Cai as measured with BCECF and the calcium photoprotein aequorin, respectively. We found that various experimental manipulations that increased pHi, such as exposure of the cells to NH4Cl, a decrease of the partial pressure of CO2 or an increase in extracellular pH in the presence of nigericin invariably increased Cai. Moreover, experimental manipulations which lowered Cai, such as a reduction of extracellular [NaHCO3] or the removal of loaded NH4 invariably decreased Cai. Thus pHi and Cai are directly related in parotid cells. Since recent studies have shown that Cai directly influences pHi, we suggest that Cai-handling and pHi-handling are tightly linked in parotid cells.
Aequorin↗
Fatal familial insomnia, a prion disease with a mutation at codon 178 of the prion protein gene.
BACKGROUND: We previously described two members of a family affected by an apparently genetically determined fatal disease characterized clinically by progressive insomnia, dysautonomia, and motor signs and characterized pathologically by severe atrophy of the anterior ventral and mediodorsal thalamic nuclei. Five other family members who died of this disease, which we termed "fatal familial insomnia," had broader neuropathologic changes suggesting that fatal familial insomnia could be a prion disease. METHODS: We used antibodies to prion protein (PrP) to perform dot and Western blot analyses, with and without proteinase K, on brain tissue obtained at autopsy from two patients with fatal familial insomnia, three patients with sporadic Creutzfeldt-Jakob disease, and six control subjects. The coding region of the PrP gene was amplified and sequenced in the samples from the two patients with fatal familial insomnia. Restriction-enzyme analysis was carried out with amplified PrP DNA from 33 members of the kindred. RESULTS: Protease-resistant PrP was found in both patients with fatal familial insomnia, but the size and number of protease-resistant fragments differed from those in Creutzfeldt-Jakob disease. In the family with fatal familial insomnia, all 4 affected members and 11 of the 29 unaffected members had a point mutation in PrP codon 178 that results in the substitution of asparagine for aspartic acid and elimination of the Tth111 I restriction site. Linkage analysis showed a close relation between the point mutation and the disease (maximal lod score, 3.4 when theta was zero). CONCLUSIONS: Fatal familial insomnia is a prion disease with a mutation in codon 178 of the PrP gene, but the disease phenotype seems to differ from that of previously described kindreds with the same point mutation.
Adolescent↗
Role of amyloid precursor protein (APP): study with antisense transfection of human neuroblastoma cells.
The function of amyloid precursor protein (APP) was investigated in human neuroblastoma La-N-1 cells by stable transfection with a DNA construct encoding antisense APP mRNA. Levels of APP mRNA, as well as proteins, were reduced by 80-90% in antisense APP transfected (ASAT) cells. ASAT cells exhibited three main features as a result of APP gene expression deprivation: (1) a 30% reduction in cell proliferation, (2) reduced cell adhesion that could be reversed by the addition of La-N-1 conditioned media as a source of secreted APP, and (3) a two- and four-fold increase in neurite-bearing cells suggesting that cellular APP may be involved in neurite extension. The first two features confirm previously reported functions for APP in proliferation and adhesion of non-neuronal cell types but the use of neuroblastoma cells in this study disclose a novel role for cellular APP in neurite extension.
Amyloid beta-Protein Precursor↗
Cholinergic and GABAergic mediations of the effects of apomorphine on serotonin neurons.
Apomorphine (APO) has been shown to elevate tryptophan, serotonin (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA) concentrations in the dorsal raphe (DR) and its corresponding projection site, the striatum, but not in the median raphe (MR) and its terminal area, the hippocampus. We have previously demonstrated that these effects are indirectly mediated through dopamine (DA) autoreceptors in the substantia nigra and possibly gamma-aminobutyric acid (GABA) neurons in or near the DR. In the present study, we have further found that the effects of APO on 5-HT neurons are also mediated through both nicotinic and M1 muscarinic cholinergic receptors as well as GABAA receptors in the DR. This suggestion is based on the findings that both atropine and mecamylamine antagonized the effects of APO, while carbachol at a high dose exerted an effect opposite to that of APO. Besides, pirenzepine and bicuculline at low doses also antagonized, whereas saclofen did not alter the influence of APO on 5-HT in the striatum. Bicuculline at a higher dose enhanced tryptophan and 5-HT measures by itself. None of the drugs studied had a significant effect on tryptophan, 5-HT, or 5-HIAA in the hippocampus. These results together suggest that DA, ACh, and GABA neurons are all involved in the actions of APO on 5-HT, while the direct synaptic relationships among these neurotransmitters and the precise anatomical locus for these interactions to occur are still unknown. It is possible that APO, by inhibiting DA neuron firing in the substantia nigra and through the GABA disinhibition mechanism, therefore indirectly activates 5-HT neurons in the DR and the striatum. While the above neuronal firing model well explains the elevation of 5-HIAA, the simultaneous increases of tryptophan and 5-HT, especially tryptophan, may be more readily explained by a mechanism of tryptophan uptake upon APO administration. Further anatomical, biochemical, and electrophysiological studies are ongoing to test this hypothesis and to clarify the circuit and the anatomical locus (loci) for these interactions to occur.
Acetylcholine↗
Fluoxetine and 8-OH-DPAT in the lateral septum enhances and impairs retention of an inhibitory avoidance response in rats.
The present study investigated the role of lateral septal serotonin (5HT) in memory consolidation and the subtype of 5HT receptors involved in this process. Rats with cannulae implanted bilaterally into the lateral septum were trained in an inhibitory avoidance task. Immediately after training, the septal serotonergic function was manipulated by pharmacological agents selectively blocking 5HT reuptake (fluoxetine and zimelidine), antagonizing 5HT2 receptors (ketanserin and ritanserin), or activating 5HT1A receptors, respectively. Results indicated that direct fluoxetine infusions into the lateral septum at a dose of 6 micrograms/0.5 microliter and zimelidine at a dose of 5 micrograms/0.5 microliter both markedly enhanced memory. Intralateral septal injections of ketanserin (0.3 microgram/0.5 microliter and 0.5 microgram/0.5 microliter) and ritanserin (0.3 microgram/0.5 microliter and 0.6 microgram/0.5 microliter) did not have a significant effect by themselves on memory, and neither did they attenuate the memory-facilitating effect of fluoxetine in the same area. Intralateral septal infusions of 8-hydroxy-2-(di-n-propylamino)tetralin at 5 micrograms/0.5 microliter significantly impaired memory retention. These findings altogether support the notion that the lateral septal nuclei of rats are involved in the memory processes of inhibitory avoidance learning. Furthermore, postsynaptic 5HT receptor activation (not the 5HT2 receptor subtype) probably exerts a facilitatory effect while presynaptic 5HT1A receptor activation exerts an impairing effect on the memory consolidation process, probably due to autoreceptor inhibition of 5HT release.
8-Hydroxy-2-(di-n-propylamino)tetralin↗
Protective efficacy of clarithromycin and its 14-hydroxy metabolite against Haemophilus influenzae in a murine septicaemia model.
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Animals↗
Estimation of the dietary riboflavin required to maximize tissue riboflavin concentration in juvenile shrimp (Penaeus monodon).
The riboflavin requirements of marine shrimp (Penaeus monodon) were evaluated in a 15-wk feeding trial. Juvenile shrimp (initial mean weight, 0.13 +/- 0.05 g) were fed purified diets containing seven levels (0, 8, 12, 16, 20, 40 and 80 mg/kg diet) of supplemental riboflavin. There were no significant differences in weight gains, feed efficiency ratios and survival of shrimp over the dietary riboflavin range. The riboflavin concentrations in shrimp bodies increased with the increasing vitamin supplementation. Hemolymph (blood) glutathione reductase activity coefficient was not a sensitive and specific indicator of riboflavin status of the shrimp. The dietary riboflavin level required for P. monodon was found to be 22.3 mg/kg diet, based on the broken-line model analysis of body riboflavin concentrations. Shrimp fed unsupplemented diet (riboflavin concentration of 0.48 mg/kg diet) for 15 wk showed signs of deficiency: light coloration, irritability, protuberant cuticle at intersomites and short-head dwarfism.
Animals↗
Characterization of an immortalized human cell line derived from neonatal foreskin diploid fibroblasts.
A new human skin cell line, designated as CCFS-1/KMC, immortalized from human neonatal foreskin diploid fibroblast cells, has been subcultured successfully in vitro for more than 500 passages. This anchorage-dependent cell line possesses many common features of transformation such as morphological and cytoskeletal changes, hypotriploidy, infinite lifespan, increasing plating efficiency and saturation density, and decreasing serum requirement and population doubling time. Human papillomavirus (HPV) type 18 DNA was detected in the cell line before and after immortalization by the polymerase chain reaction (PCR) method. Tumorigenicity, however, was not demonstrated in vivo. The isoenzyme activity of the cell line shows activation of a placental form of alkaline phosphatase and a changing lactate dehydrogenase isoenzyme pattern that is different from transformation by carcinogens. Class I HLA and class II HLA antigens are constitutively expressed on this skin cell line. Here we report that these immortalized human fibroblasts derived from neonatal HPV-18-DNA-contained diploid fibroblasts possess double minute chromosomes (DMs), a karyotypic aberration usually found in cancer cells.
Cell Division↗
Computerized psychiatric diagnoses based on euclidean distances: a Chinese example.
Current diagnostic methods in psychiatry use sequential logical decision rules that generate a single diagnosis. Insufficient attention has been paid to parallel methods that can simultaneously determine the relative probability of many diagnoses. This study installed 45 items from various symptom scales on a portable computer and applied a euclidean distance formula to generate immediate diagnoses based on responses to the items. The reliability and validity of the method were assessed using Chinese psychiatric inpatients. Interrater reliability was excellent (kappa = 0.91) and 3-week test-retest reliability was fair (k = 0.50). The concordance of this method with clinicians' diagnoses and with diagnoses based on standardized Chinese diagnostic criteria was excellent (k = 0.73 and 0.76). Concordance with DSM-III-R diagnoses and ICD-10 diagnoses was fair (kappa = 0.55 and 0.65). The clinical utility of such parallel methods of psychiatric diagnosis deserves further evaluation.
Bipolar Disorder↗
High prevalence of hepatitis C virus infection in aborigines in Taiwan.
In Taiwan, the epidemiological status of HCV infection is similar to those observed in other areas of the world, with 1.0% prevalence among adult volunteer blood donors and high prevalences among the high risk groups, by the detection of anti-HCV with synthetic peptide antigens. However, unusually high prevalences, 35.1%, 15.8% and 14.2%, were observed among adult populations in three of the five aboriginal communities. No difference in sex specificity was noted. In 37 (75.0%) of the 48 anti-HCV-positive cases, HCV-RNA was detected by reverse transcription polymerase chain reaction (RT-PCR) assay. None of such particular risk factors as tattooing, sexual promiscuity, operation, blood transfusion, nor intravenous drug abuse could be accounted for this high prevalence of HCV infection. No helpful supporting evidence for ethnic specificity was noted, either. Although a possible sexual transmission between spouses was observed, it is unlikely to be the main cause of the high prevalence in these aboriginal communities. We conclude that the unusually high prevalence of HCV infection observed in some aboriginal communities in Taiwan could be ascribed to poor anti-septic medical practice derived from insufficiency of medical personnel and facilities in these communities as compared with the other regions in Taiwan at the time before twenty years ago.
Adolescent↗
Spontaneous production of growth factors for human lymphocytes from a human papillomavirus type 18-contained foreskin fibroblast cell line.
An immortalized fibroblast cell line, designated as CCFS-1/KMC, derived from human neonatal foreskin fibroblasts, contained human papillomavirus (HPV) type 18 DNA. Since this newly established cell line could spontaneously secrete activating factors for normal human blood lymphocytes, the synthesis and release of potent inflammatory cytokines from this cell line were checked. To determine the presence of cytokines in the supernatant collected from the cell line, tests by a cytokine-specific ELISA and a mitogenesis bioassay were done. The cell line could spontaneously produce several immunoreactive cytokines, such as tumor necrosis factor (TNF), interleukin 1 (IL-1) and interleukin 6 (IL-6). It also could stimulate the mitosis of human blood lymphocytes and Raji lymphoblast cell line. These cytokines were present in the same fraction of isoelectric points (pI) from 5.4 to 5.6. This study suggests that non-immune bystander cells may exert immunomodulatory effect on the immune cells via the production of potent inflammatory cytokines during viral infection.
Cell Line↗
Somatic expression of herpes thymidine kinase in mice following injection of a fusion gene into eggs. 1982.
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Animals↗
Detection and differentiation of dengue-1 from Japanese encephalitis virus infections by ABC MAC-ELISA.
An IgM antibody capture enzyme linked immunosorbent assay using avidin biotin complex system (ABC MAC-ELISA) was established for the detection and differentiation of dengue-1 and Japanese encephalitis virus infections. The cut-off value of MAC-ELISA was based on the mean value of optical density at 490 nm of seven negative human sera carried along in each assay multiplied by 2.1. The specificity of MAC-ELISA tested on 200 healthy enrolled male serum was 99.5% and 98.0% for dengue-1 and Japanese encephalitis IgM, respectively. Two hundred and sixty-six acute or followed-up dengue serum specimens which were identified to possess dengue-1 virus by virus isolation technique using C6/36 cell line and monoclonal antibody immunofluorescent assay (IFA) were tested by MAC-ELISA for IgM antibodies to dengue-1 and Japanese encephalitis virus infection. The positivity of IgM antibody for serum collected from day 1 to day 7 after onset of the disease was 0.0%, 0.0%, 7.6% 14.2%, 25.0%, and 77.7% by each consecutive day, correspondingly, for those collected from day 8 to two month was 96.7% overall. By comparison the P/N value of dengue-1 IgM to JE IgM, 98.5% and 96.8% of the dengue-1 and Japanese encephalitis suspected serum specimens could be distinguished from each other, respectively. MAC-ELISA is a convenient, rapid, sensitive and specific method for the detection and differentiation of dengue-1 from Japanese encephalitis virus infections.
Antibodies, Viral↗
Prenatal cytogenetic diagnosis in amniocentesis.
From 1982 to 1990, cytogenetic studies were successfully conducted in 2,975 (96.19%) of the 3,096 pregnant women who underwent amniocentesis. The average maternal age was 33.7 years and the average gestational age was 18.1 weeks. Common indications of amniocentesis included advanced maternal age (AMA) (54.76%), previous fetus with chromosomal aberrations (6.82%) or gross anomalies (5.01%), intrauterine gross anomaly (4.97%) and maternal exposure to drugs or radiation (5.28%). Among the 89 cases (2.99%) with detected chromosomal aberrations, 53 were numeric (31 trisomies, 21 sex chromosome aberrations and one tripoidy) and 36 were structural (six de novo and 30 hereditary structural rearrangement). The incidence of chromosomal aberrations was 2.03% in cases with AMA. While only four of the 143 cases with previous fetal trisomy 21 had recurrence, the recurrent rate was 90.91% in 11 cases with previous fetal chromosomal translocation. Thirty (20.27%) of the 148 cases with abnormal sonograms showed chromosomal aberrations. Certain congenital anomalies are closely associated with cytogenetic changes: duodenal atresia and trisomy 21; cystic hygroma and 45,X; and polyhydramnios and trisomy 18. Only two of the 157 cases with indications of drug or radiation exposure had abnormal cytogenetic studies. Two of the 53 cases with detected numerical aberrations (47,XXY and 47,XXX) and 27 cases with hereditary structural rearrangement elected to continue their pregnancies. All of these babies were delivered without gross anomalies. This study suggests that for prenatal diagnosis. However, complementary measures, such as routine antenatal ultrasound and maternal serum alphafetoprotein, should be added to increase the efficacy of genetic amniocentesis.
Adolescent↗
The effect of third-trimester glycemic control on maternal and perinatal morbidities in pregestational diabetes mellitus.
From May 1974 to March 1989, 48 cases of pregestational diabetes mellitus treated during the third trimester of pregnancy at the Obstetric Clinic of the National Taiwan University Hospital had complete maternal-fetal chart, and were enrolled into this retrospective review. Of these cases, 28 were class B, 13 were class C and seven were class D-R. The maternal complications and perinatal morbidities of each class were reviewed. The mean fasting, postprandial plasma glucose concentrations and the mean excursion of plasma glucose levels were calculated for statistical analysis. Among the maternal complications, urinary tract infections and preterm labor were significantly associated with mean fasting plasma glucose concentrations. Among perinatal morbidities, neonatal respiratory distress and metabolic problems (including neonatal hyperbilirubinemia, symptomatic hypoglycemia, hypocalcemia and polycythemia) were significantly associated with mean plasma fasting glucose concentrations, and perinatal asphyxia was associated with a mean excursion of plasma glucose levels. In view of the paucity of knowledge about the etiology of complications in diabetic pregnancies, it is necessary to conduct a prospective multi-center study with well-characterized morbidities to search for the role of glycemic control in obstetric and perinatal complications.
Blood Glucose↗
Amplification of dengue 2 virus ribonucleic acid sequence using the polymerase chain reaction.
The polymerase chain reaction (PCR) has been adapted to the amplification of dengue type 2 virus (DEN2) nucleic acid sequences. A pair of 20-mer oligonucleotides were designed and synthesized based on conserved sequence blocks of DEN2 strains isolated from different geographical areas. RNA samples were prepared from two DEN2 strains, prototype New Guinea C (NGC) and local isolate Hainan 98 (HN98). The reverse transcription step was performed for cDNA synthesis before the standard PCR procedures. The amplified products were fragments about 476 bp in length, corresponding to the upper one third of DEN2 envelope gene (E1 to E476 nt). Specificity of the amplification products was confirmed by "nested" PCR using the internal primers and by Southern and dot blot hybridization to cloned DEN2 cDNA probes following agarose gel electrophoresis. Further improvement and the potential application of the methods in study of dengue virus RNA are discussed.
Base Sequence↗
Thalamic hand: a late onset sequela of stroke and its influence on physical function after rehabilitation: two cases report.
Thalamic hemorrhage or infarction is one of the common causes of stroke. People who suffer from this type of cerebrovascular disease may develop thalamic syndrome which includes sensory disturbance, motor deficit and psychological problems. In this report, we introduce two cases of thalamic hemorrhage followed up for more than a half year after stroke. Delayed rigidity and choreodystonic type of involuntary movement over their paretic hand developed gradually. The metacarpophalangeal joints of the affected hand were kept flexed and the proximal and distal interphalangeal joints became extended. Thalamic hand is demonstrated in the appended pictures. Once the patient develops a thalamic hand, activities of daily living will be affected due to poor hand performance despite of high motor recovery stage. Early recognition and proper rehabilitation program for the patients with thalamic hand are emphasized.
Cerebral Hemorrhage↗