Search PubMed⌕ Search

Biomedical subjects

Y H Wu

Publications and source records attributed to Y H Wu.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Effects of repeated low body negative pressure (LBNP) exposures on LBNP tolerance].

OBJECTIVE: To investigate variation of low body negative pressure (LBNP) tolerance and the relationship with change of heart function after repeated LBNP exposures. METHOD: Ten healthy subjects were exposed to eight min consecutive daily LBNP (-50 mmHg). Before and after this exposures, tolerance to LBNP was determined by a cumulative stress index (CSI) and duration of negative pressure (DNP). RESULT: The pre- and post repeated exposure values of CSI and DNP were 1058 +/- 216 s, 1354 +/- 233 s and 45833 +/- 12546 s mmHg, 63433 +/- 13458 s mmHg, respectively. It showed that both were increased significantly (P<0.05), and the heart function was showed to have a tendency of being enhanced. CONCLUSION: It suggested that LBNP tolerance increased after repeated exposures, which might be achieved via strengthening of ventricular contractivity, decreasing the compliance of peripheral vascular, the hypotensive [correction of hypotentive] reflex compensatory mechanisms becoming more effective, and increasing arterial blood pressure on heart level.

Adaptation, Physiological↗
PubMed1999

Identity of a novel swine hepatitis E virus in Taiwan forming a monophyletic group with Taiwan isolates of human hepatitis E virus.

Recently, we found that more than 10% of the cases of acute non-A, non-B, non-C hepatitis in Taiwan were caused by a novel strain of hepatitis E virus (HEV). Since none of these patients had a history of travel to areas where HEV is endemic, the source of transmission remains unclear. The recent discovery of a swine HEV in herd pigs in the United States has led us to speculate that HEV may also circulate in herd pigs in Taiwan and may serve as a reservoir for HEV in Taiwan. Of 275 herd pigs obtained from 10 pig farms in Taiwan, 102 (37%) were seropositive for serum anti-HEV immunoglobulin G (IgG). A 185-bp genomic sequence within the ORF-2 of the HEV genome was amplified and cloned from serum samples of an anti-HEV positive pig and subsequently from serum samples of a patient with acute hepatitis E. Sequence comparison revealed that the swine and human isolates of HEV share 97.3% identity. Phylogenetic analyses further showed that the Taiwan swine and human isolates of HEV form a distinct branch divergent from all other known strains of HEV, including the U.S. swine strain. To examine the potential risk of cross-species transmission of swine HEV to humans, the seroprevalences of anti-HEV IgG in 30 swine handlers, 20 pork dealers, and 50 control subjects were assessed and were found to be 26.7, 15, and 8%, respectively (for swine handlers versus controls, P = 0.048). Our findings may help provide an understanding of the modes of HEV transmission and may also raise potential public health concerns for HEV zoonosis.

Animals↗
PubMed1999

High prevalence of TT virus infection in healthy children and adults and in patients with liver disease in Taiwan.

A newly identified DNA virus, named TT virus (TTV), was found to be related to transfusion-associated hepatitis. We conducted the following experiments to evaluate its pathogenic role in liver disease and potential modes of transmission. We used PCR to detect TTV DNA in serum. The rates of TTV viremia in 13 patients with idiopathic acute hepatitis, 14 patients with idiopathic fulminant hepatitis, 22 patients with chronic hepatitis, and 19 patients with cirrhosis of the liver were 46, 64, 55, and 63%, respectively, and were not significantly different from those in 50 healthy control subjects (53%). PCR products derived from seven patients with liver disease and three healthy controls were cloned and then subjected to phylogenetic analyses, which failed to link a virulent strain of TTV to severe liver disease. TTV infection was further assessed in an additional 148 subjects with normal liver biochemical tests, including 30 newborns (sera collected from the umbilical cord), 23 infants, 16 preschool children, 21 individuals of an age prior to that of sexual experience (aged 6 to 15 years), 15 young adults (aged under 30 years), and 43 individuals older than 30 years. The rates of TTV viremia were 0, 17, 25, 33, 47, and 54%, respectively. These findings suggest that TTV is transmitted mainly via nonparenteral daily contact and frequently occurs very early in life and that TTV infection does not have a significant effect on liver disease.

Adolescent↗
PubMed1999

Octreotide treatment for a malignant islet cell tumor with variable hormone secretion: case report.

It is well known that an islet cell tumor can secrete multiple hormones depending on its cell type. We report the case of a 70-year-old woman who initially presented with peptic ulcer symptoms, an elevated serum gastrin level, and multiple liver tumors. Liver biopsy and distal pancreatectomy were performed, and the pathological diagnosis was malignant islet cell tumor. Additionally, the immunohistochemical staining revealed scattered positivity for gastrin, and then also positivity for insulin 14 months later. A subsequent hypoglycemic episode and elevated serum gastrin and insulin levels suggested that the disease had developed into a condition of multiple hormone secretion. The plasma gastrin and insulin levels decreased from 584 pg/ml and 90.8 microIU/ml to 49.1 pg/ml and 20.9 microIU/ml, respectively, 5 days after treatment with subcutaneous octreotide 100 micrograms every 6 to 8 hours. In addition, follow-up computed tomography showed shrinkage of the metastatic liver tumors. In conclusion, we found a case of malignant islet cell tumor with variable hormone secretion which could be effectively controlled with octreotide.

Aged↗
PubMed1999

Staphylococcus capitis bacteremia of very low birth weight premature infants at neonatal intensive care units: clinical significance and antimicrobial susceptibility.

Coagulase-negative staphylococci (CNS) are frequently isolated from blood cultures in critically ill neonates. However, Staphylococcus capitis is rarely reported as a pathogen in human beings. From January, 1995 to December, 1997 at a tertiary care neonatal intensive care unit (NICU), a total of 147 (62%) CNS isolates were detected from 236 positive blood cultures, including 27 isolates of S. capitis. Among the S. capitis bacteremia, 17 isolates were judged to be infections as opposed to 10 of the noninfection cultures. The occurrence of S. capitis infection was correlated with long hospital stay (52 +/- 17.6 days vs. 28 +/- 18.5 days, p=0.003) and total parenteral nutrition administration (46 +/- 17.4 days vs. 22 +/- 19.1 days, p=0.006). Apnea, bradycardia, temperature instability and poor activity were the predominant clinical features. Among the 17 episodes of bacteremia, one patient had complicated septic meningitis. There is no statistical significance between S. capitis infection and the duration of a central venous catheter placement (37 +/- 17.5 days vs. 26 +/- 19.5 days, p=0.165). No catheter related infection was proven. Removal of a percutaneous central venous catheter routinely in patients with S. capitis bacteremia is not recommended. All the patients survived after antibiotic treatment. The prevalence rate of multiple resistant S. capitis was 94%. All isolates were resistant to oxacillin, erythromycin and clindamycin but susceptible to ampicillin/sulbactam, vancomycin and teicoplanin. Empiric therapy for S. capitis infection in NICU with ampicillin/sulbactam is therefore recommended. It is important to detect S. capitis which has a high degree of antibiotic resistance in order to treat the patient correctly. S. capitis should be included as etiology and the possibility of nosocomial outbreak in very low birth weight (VLBW) premature infants at NICU.

Bacteremia↗
PubMed1998

Successful recovery of 14 patients afflicted with full-thickness burns for more than 70 per cent body surface area.

Fourteen cases suffering full-thickness burns of more than 70 per cent total body surface area (TBSA) have been successfully treated during the last 8 years (1988-1995). Among these patients, 10 cases suffered from burns of more than 90 per cent TBSA. Five cases had full-thickness burns of 80-90 per cent TBSA. Escharectomy, followed by coverage of wounds with a homograft to the lower surface of which, adjacent to the wound bed, microautoskin grafts had been attached was employed to close wounds in the early stages after burn. The remaining non-surgically treated wound was treated by exposure and topical silver sulfadiazine. The temperature and humidity of the ward was controlled by air conditioning and dehumidification. Aggressive excision of eschar and auto-skingrafting was carried out 3 weeks post-injury. Strictly limiting the uncovered wound to less than 5 per cent appeared to be the major effective measure in preventing burn infection.

Administration, Topical↗
PubMed1998

A KP element inserted between the two promoters of the alcohol dehydrogenase gene of Drosophila melanogaster differentially affects expression in larvae and adults.

An allele of the Drosophila melanogaster alcohol dehydrogenase (Adh) gene has a 1.15-kb KP element inserted, in the same orientation as Adh transcription, five nucleotides upstream of the distal transcription start site. The target site--GTCCAAGT--in Adh between nucleotides -13 and -6 is duplicated at both ends of the insertion. Adult flies with either one or two copies of the allele have less than 12% of the alcohol dehydrogenase (ADH) activity of the controls. Activity levels are also reduced in larvae, but by a much smaller amount. Quantitative Northern analyses showed that the low activity level in adults was caused by reduced transcript levels from the distal promoter. 5' RACE experiments indicated that adult transcripts were mostly initiated downstream of the distal promoter but some skipped the first adult exon. In late third-instar larvae the transcripts present were from the proximal promoter. After the KP element was deleted by an appropriate breeding program, the distal transcript increased in adults to the control level, but ADH activity increased to only 50% of the control. No nucleotide changes were found in the gene that could explain this difference.

Alcohol Dehydrogenase↗
PubMed1998

Effects of aluminum potassium sulfate on learning, memory, and cholinergic system in mice.

AIM: To study the relationship between aluminum potassium sulfate (APS) and memory deficits of mice. METHODS: 30, 60, or 90 d after the mice were given daily APS i.g., the step-through latency (STL) was determined with a passive avoidance task. Aluminum (Al) contents in brain and blood were assayed with atomic absorption spectrophotometry. Acetylcholine (ACh) content in brain was determined with chemiluminescent method and choline acetyltransferase (ChAT) activity was measured radiochemically. RESULTS: APS 1 g.kg-1 increased blood-Al only after 30 d. After 60 d, STL, ACh content and ChAT activity decreased by 46.4%, 8.5%, and 22.6%, respectively. These parameters decreased by 50%, 11.1%, and 27.8%, respectively, with increased Al in blood and brain, after 90 d. APS 0.25 g.kg-1 had no effects on mice except blood-Al. In ethylcholine mustard aziridium chloride (AF64A) treated mice, APS 1 g.kg-1 only increased blood and brain-Al. CONCLUSION: The intake of APS 1 g.kg-1.d-1 for 60 d induced learning and memory deficits in mice.

Acetylcholine↗
PubMed1997

In vitro enamel demineralization and the marginal gap of simulated cast restorations with three different cements.

PURPOSE: This study investigated 1) the relationship between marginal gap sizes and enamel demineralization, and 2) the influence of three cements on this enamel demineralization. MATERIALS AND METHODS: Horizontal sections of 60 noncarious, freshly extracted human third molars were randomly assigned to one of four groups. Simulated cast restorations were attached to the specimens with 1) zinc phosphate cement, 2) glass ionomer cement, 3) composite resin cement, or 4) no cement (control). The tooth/restoration gaps were controlled at 51, 102, and 204 microns. The specimens were incubated for 16 weeks in buffered lactic acid gelatin to induce demineralization. Photomicrographs were obtained from sections of each sample using a polarized light microscope. Three evaluators measured wall and primary enamel lesion depths allowing for the determination of a demineralization ratio (DR). Data were analyzed by repeated-measures ANOVA (alpha = 0.05). RESULTS: The between-evaluator effects were not significant. All evaluators agreed that DR was significantly related to cement (p = .0001) but not to marginal gap size. The resin cement had the smallest DR (0.7 +/- 0.3), and the control group had the greatest (4.4 +/- 2.0). CONCLUSIONS: The presence of any one of the three investigated cements resulted in decreased demineralization. The amount of demineralization was unaffected by marginal gap size.

Analysis of Variance↗
PubMed1996

Repair of a giant scleral ulcer with preserved sclera and tissue adhesive.

BACKGROUND AND OBJECTIVE: Infectious scleral ulcer is a rare but severe late complication of pterygium surgery. Scleral grafts may be required in scleral ectasia with uveal exposure, corneal distortion, and severe anterior chamber reaction that are induced by scleral ulcer. The authors report a method for scleral grafting with preserved sclera and tissue adhesive. PATIENTS AND METHODS: Six cases of infectious scleral ulcers were repaired with this method. Preserved sclera was attached to the thinning sclera with tissue adhesive without sutures. The free or rotation conjunctival flap was placed over the graft area and sutured with 10-0 nylon. RESULTS: The six cases repaired by this method showed good results during the follow-up, except for one loss. The only complication was protrusion of the adhesive postoperatively. This protrusion can be easily removed with forceps on an outpatient basis. CONCLUSION: Tissue adhesive with preserved sclera is a useful method for repair of scleral thinning.

Aged↗
PubMed1994

A cultured malignant B-1 line serves as a model for Richter's syndrome.

Human chronic lymphocytic leukemia (CLL) is a malignancy of B-1 cells characterized by the accumulation of mature appearing, long lived, slow growing B-1 cells in peripheral blood. CLL occasionally evolves into an aggressive large cell lymphoma termed Richter's syndrome. NZB mice can be used to model the early stage of CLL because aged NZB mice can spontaneously develop slow growing malignant B-1 cell clones. The malignant NZB B-1 clones fail to grow in culture and are typically carried in vivo as passaged lines. During serial passage, an aggressive lymphoma developed as a result of a continued transformation of the original B-1 clone, similar to the development of Richter's syndrome. An in vitro cell line was established from the aggressive lymphoma, which was stromal dependent and could rapidly metastasize when passaged into recipient animals. Analysis of adhesion molecules did not reveal any consistent characteristics that could account for the metastatic potential of the Richter's-like cells. In addition, the aggressive in vitro line had the identical heavy chain sequence as the slow growing NZB malignant B-1 clones. The in vitro and in vivo aggressive B-1 cells had very high levels of IL-10 message, and underwent more apoptosis in response to anti-IgM than did nonaggressive B-1 clones. Taking these characteristics together, we have composed a comprehensive animal model system for human CLL that includes both the aged NZB mice for the early stage and the recipients of the in vitro B-1 line for the late stage or Richter's syndrome. This model system can be used to study, not only the ontogeny and genetic linkage of CLL, but also the regulatory factors involved in transformation and growth both in vivo and in vitro.

Animals↗
PubMed1994

[Study on motilin and spleen-yin deficiency].

The Plasma motilin level in 44 cases patients with Spleen-Yin deficiency (SYD) was observed and compared with Spleen-Qi Insufficiency (SQI), the normal control group. SYD patients were treated using self-made Shen Rou Yang Zhen Tang oral liquor. The results showed that plasma motilin level was higher significantly than that of the control group (P < 0.01), but was remarkably lower than that of SQI. The difference was significant among the three groups (P < 0.01). The abnormal incidence of positive plasma motilin was 65.91% and 75.00% respectively. It is conjectured that the plasma motilin level in SYD was related to excitability of vagus nerve, disturbance of gastro-intestinal internal environment, indigestion and malabsorption of GI tract.

Adult↗
PubMed1992

[Glucocorticoid receptor (GCR) in canine peripheral lymphocyte during early postburn period].

In this report, using the radio-ligand binding assay with [3H]-dexamethasone (Dex) as the ligand, we studied the changes in glucocorticoid receptor (GCR) in canine peripheral lymphocyte under unstressed condition and during the early postburn period (within 48 hours after burn). The results showed that the apparent binding capacity (Ro) and the apparent dissociation constant (Kd) of GCR were 8468 +/- 993 sites per cell and 10.2 +/- 0.6 nM (n = 6), respectively, under unstressed condition. The number of [3H]-Dex specific binding sites measured by the single saturated analysis (Rs) from 16 healthy mongrel dogs under unstressed condition was 4531 +/- 396 sites per cell. The Rs was decreased sharply at the second post-burn hour, reaching the lowest level of 2501 +/- 460 sites per cell. But it recovered to 78.9% of the level measured in unstressed condition. There was significant negative relationship between the plasma cortisol concentration and GCR levels of lymphocyte. The results suggest that the changes in GCR in postburn period may be related to the down-regulation of GCR by Gc; that GCR may be of very important significance in the pathophysiologic changes after burn injury.

Animals↗
PubMed1991

Radioimmunolocalization of human malignant tumors with In-111 labeled monoclonal antibody.

An anti-human colon carcinoma monoclonal antibody 2C10 was radiolabeled with In-111 and studied in 15 patients with gastrointestinal and ovarian carcinoma. The labelling efficiency approached 100% and immunoactivity of the labeled antibody was over 75%. 2-3 mCi (1 mg) In-111-2C10 was given to the patients intravenously and scintigraphy was performed 72 hours after administration with a gamma camera. Specimens were also scanned in some of the patients. The resected tumors and remote margin were examined immunohistochemically. Positive scintigraphic images were obtained in 12/15 patients with colorectal cancer (10) and ovarian cancer (2). Negative results were seen in the two patients with gastric cancer. The scintigraphic results of 10 patients were confirmed surgically and pathologically. The remaining 5 were confirmed by endoscopy, B-ultrasonography or X-ray CT. Most patients had been definitely diagnosed before imaging except one patient with metastatic focus from ovarian cancer to colon and one with recurrent colon cancer were first detected with RIAD, showing the unique advantage the latfer. The high background radioactivity in the liver, however, is a conspicuous problem to be solved.

Adult↗