Search PubMed⌕ Search

Biomedical subjects

Y J Yang

Publications and source records attributed to Y J Yang.

At least 55 records · Page 3Linked to original sources
PubMed1999

Prognostic determinants of infective endocarditis in the 1990s.

The clinical profiles of infective endocarditis (IE) might have changed in recent years, owing to the advent of transesophageal echocardiography, the introduction of new diagnostic criteria, and the increased frequency of intravenous drug abuse. In this retrospective study, we sought to identify factors affecting the in-hospital outcome of IE patients in a single tertiary referral center in the 1990s (1990-1997). Eighty-eight episodes of IE in 80 consecutive patients admitted from January 1990 through June 1997 were evaluated. Clinical variables that were significantly associated with in-hospital mortality in univariate analyses were entered into a multiple logistic regression model. A total of 22 patients (25%) died. Fatal episodes were significantly more likely than non-fatal episodes to involve older patients (> or = 50 years), use of coumadin, short interval between symptom onset and hospitalization (< 15 days), noncardiac shock, and complications of the heart, central nervous system, and kidneys. White blood cell counts and C-reactive protein concentrations were also significantly higher in fatal than in non-fatal episodes of IE. Multivariate analysis showed that in-hospital mortality was associated with noncardiac shock, neurological complications, cardiac complications, and older age (> or = 50 years). Compared with previous reports, our findings suggest that the clinical profiles of IE have undergone some changes in the 1990s. The most important prognostic predictors of in-hospital mortality in patients with IE were noncardiac shock and neurologic complications.

Adolescent↗
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

High rates of antimicrobial resistance among clinical isolates of nontyphoidal Salmonella in Taiwan.

To assess trends in antimicrobial-resistant Salmonella infections from 1989 to 1996 in southern Taiwan, the minimum inhibitory concentrations (MICs) of 14 antibiotics or antibiotic combinations were determined by the agar dilution method for 297 clinical isolates of nontyphoidal Salmonella. The rates of resistance to ampicillin, chloramphenicol, and tetracycline were 65, 67, and 78%, respectively. Resistance to trimethoprim-sulfamethoxazole (TMP-SMX) increased from 25% in 1989-1992 to 35% in 1993-1996 (P=0.057). For new quinolones and extended-spectrum cephalosporins, no resistant strains were encountered. Multiple resistance to more than five antimicrobial drugs doubled from 10.6% in 1989-1992 to 19.7% in 1993-1996. Multiply resistant salmonellae were isolated more commonly from blood samples than from feces (30% vs. 14%, P<0.05). In Taiwan, ampicillin, chloramphenicol, and even TMP-SMX are no longer the drugs of choice for treatment of serious nontyphoidal Salmonella infections. Extended-spectrum cephalosporins are now the preferred drugs in Taiwan for treatment of invasive Salmonella infections in children.

Anti-Bacterial Agents↗
PubMed1998

Fatal coxsackievirus B infection in early infancy characterized by fulminant hepatitis.

OBJECTIVES: to clarify the major features of fatal coxsackievirus B infection characterized by fulminant hepatitis in early infancy. METHODS: clinical manifestations and laboratory investigations concerning five consecutive young infants with overwhelming coxsackievirus B fulminant hepatitis between 1994 and 1997 were retrospectively reviewed. Aetiological diagnosis was made by viral cultures and confirmed by a neutralization test with a type-specific antiserum. RESULTS: all five had a deteriorating clinical course of severe hepatitis complicated by disseminated intravascular coagulopathy (DIC). Coxsackievirus B1 infection was established in four patients and coxsackievirus B3 in one. The pathological findings of the two cases illustrated extensive hepatocellular necrosis. Fulminant hepatitis can occur as a leading presentation of disseminated coxsackievirus B infections and dominant the clinical features in neonates and young infants. CONCLUSIONS: the liver was the target organ of fatal coxsackievirus B infection in our patients. Hepatic involvement progressed rapidly to jaundice and coagulopathy, and was considered to be indicative of poor prognosis. Coxsackievirus B hepatitis may be serious in early infancy.

Coxsackievirus Infections↗
PubMed1998

Absence of an analgesic effect of qigong "external qi" in rats.

The analgesic effect of "external Qi" emitted from the Qigong practitioner was investigated in rats. In behavioral experiments, the rat's tail-flick and head-movement threshold measurements were used to determine if the "external Qi" had analgesic effect. The results were negative. In electrophysiological study, the "external Qi" shows no significant changes in the pain-related evoked cortical potentials to tooth-pulp stimulation. Thus the results of this study are different from those reported by other investigators. It is proposed that this research be repeated and extended.

Analgesia↗
PubMed1998

Group B streptococcal infections in children: the changing spectrum of infections in infants.

During a 9-year period from January 1988 to December 1996, 36 patients less than 18 years of age with Lancefield group B streptococcal infections were seen in the National Cheng Kung University Hospital. Among 33 infants with invasive group B streptococcal infections, 3 (9%) were early onset disease (EOD), 27 (82%) late onset disease (LOD) and 3 (9%) onset beyond the third month of life. All cases of EOD were detected during the first day of life and 2 of them were premature births. In the infants with LOD, a high incidence of meningitis occurred (78%). The most common clinical presentation in group B streptococcal infections was fever (81%), followed by irritable crying (42%) and poor feeding (39%). Seizure was noted in 57% of meningitis cases. Obstetric and neonatal risk factors were compared between EOD and LOD, with prematurity and low birth weight significantly (P=0.01) more common among infants with EOD compared with LOD. Of the strains tested, the sensitivity to penicillin, ampicillin and erythromycin were 83%, 74%, and 75%, respectively. All strains were resistant to tetracycline and gentamicin. There were 2 case fatalities (6%) and 6 (17%) had major neurologic sequelae. These data provide that the vast majority of EOD are recognized on the first day of life and prematurity is an important risk factor. In comparison to the previous report in Taiwan, a changing spectrum of GBS infections in infants occurs during the study period. The observed incidence of EOD is decreased and meningitis is still predominantly in LOD. It is suggested early recognition and aggressive therapy have resulted in a much lower mortality rate than previously reported.

Adolescent↗
PubMed1997

The role of microvascular permeability in the mechanism for stunned myocardium in rats.

The microvascular permeability of stunned myocardium in rats in vivo was studied with FITC-labeled albumin (FITC-BSA). It was found that 15 and 20 min of myocardial ischemia followed by 1 hr of reperfusion resulted in myocardial stunning. The concentrations of FITC-BSA in myocardial tissue were 240.6 +/- 7.8 (IS15) and 267.4 +/- 7.9 (IS20) micrograms/g myocardium in ischemic groups, respectively, which were significantly higher than those in the control group (166.0 +/- 7.9 micrograms/g myocardium; P < 0.01). In stunned groups, the concentrations were 224.8 +/- 11.8 (MS15) and 241.7 +/- 6.0 (MS20) micrograms/g myocardium, decreased from those in ischemic groups but still higher than those in control group by 35.4 and 45.6%, respectively. The more significant the concentration of FITC-BSA, the more serious the myocardial stunning. Electron microscopy revealed no significant vascular injury. The results suggest that the increase in microvascular permeability resulting from transient ischemia is functional and is involved in the pathogenesis of stunned myocardium.

Animals↗
PubMed1997

Effect of infection brain edema on NMDA receptor binding in rat brain in vivo.

The purpose of this study was to determine the effect of infection brain edema (IBE) in the rat model induced by injecting pertussis bacilli (PB) into the left carotid artery. The specific binding of N-methyl-D-aspartate (NMDA) receptor with [3H] MK-801 was measured in the neuronal membrane of cerebral cortex. The Scatchard plots were performed. The Bmax values were 0.623 +/- 0.082 and 0.606 +/- 0.087 pmol/mg protein in the group that received normal saline (NS) and PB respectively (P < 0.05). The Kd values were 43.1 +/- 4.2 and 30.5 +/- 3.0 nM in the groups NS and PB respectively. The results indicated that the affinity of NMDA receptor was significantly higher in the group PB than group NS, whereas the total number of NMDA receptors had not changed in the IBE model. The increase of affinity of NMDA receptor can be blockaded by MK-801 pretreatment in vivo.

Animals↗
PubMed1997

Aluminum utensils contribute to aluminum accumulation in patients with renal disease.

Presently, aluminum utensils are widely used in the world, especially in the developing countries. However, whether aluminum leaching from such utensils contributes to aluminum accumulation or causes any damage in patients with renal disease remains unknown. We designed a prospective study to evaluate this problem. After excluding patients who were not examined at follow-up or who poorly complied during the study period, the opened randomized study consisted of 42 patients with chronic renal insufficiency (creatinine clearance <60 mL/min and >10 mL/min). All patients had not taken any aluminum-containing agents for 3 months, but used aluminum kitchen utensils for more than 1 year. Twelve patients comprised the control group; the other 30 patients comprised the study group. The aluminum kitchen utensils used by the study group patients were replaced with stainless steel utensils for 3 months, but those used by the control group were not. After 3 months, the decrements of serum aluminum (5.5 +/- 4.6 microg/L v 2.1 +/- 3.5 microg/L; P = 0.012) and daily urine aluminum excretion (14.3 +/- 15.2 microg/d v 2.1 +/- 5.6 microg/d; P = 0.005) in the study group patients were greater than those in the control group patients. The increments of transferrin saturation of the study group patients (1.8% +/- 9.5% v -3.7% +/- 9.5%; P = 0.052) were greater than those of the control group patients. In addition, the increments of iron (r = 0.368, P = 0.035) and transferrin saturation (r = 0.345, P = 0.049) positively correlated with the decrements of daily aluminum excretion in all patients. The study group patients with greater decrements of serum aluminum (>5.5 microg/L) had greater serum iron levels (90.2 +/- 27.7 microg/dL v 71.9 +/- 27.8 microg/dL; P = 0.047) and transferrin saturation (30.5% +/- 11.0% v 23.0% +/- 9.5%; P = 0.046) than those with less decrements of serum aluminum (<5.5 microg/L) after the study. Our study demonstrates that aluminum kitchen utensils may be the important aluminum exposure source for patients with chronic renal insufficiency who are not taking aluminum-containing agents, and hints that the long-term exposure of aluminum leaching from aluminum utensils probably affects iron levels in patients with chronic renal insufficiency. Further studies are clearly needed to confirm this observation.

Adult↗
PubMed1997

Effect of sodium glycyrrhetinate on chemical peritonitis in rats.

AIM: To study the anti-inflammatory mechanisms of sodium glycyrrhetinate (SG). METHODS: Rat chemical peritonitis was used. The protein content and prostaglandin E2 (PGE2) content in exudate were measured by Folin-phenol assay and RIA, respectively. SOD activity in neutrophils (Neu) was determined by pyrogallol-NBT colorimetry. cAMP content in Neu was detected by competitive protein binding assay. RESULTS: In peritonitis caused by histamine, SG 10-20 mg.kg-1 i.m. reduced exudate volume and Neu counts, and 5-20 mg.kg-1 i.m. lowered the protein content in exudate. In peritonitis induced by carrageenan, SG 20 mg.kg-1 i.m. reduced exudate volume, Neu counts, protein content and PGE2 content in exudate, increased SOD activity in Neu, but did not affect beta-glucuronidase release from Neu. In peritonitis induced by arachidonic acid, SG 20 mg.kg-1 i.m. reduced Neu counts, protein content, and PGE2 content in exudate, and attenuated the reduction of cAMP level in Neu. CONCLUSION: SG exerts its anti-inflammatory action by lowering permeability of capillaries in inflammatory site, inhibiting Neu emigration and PGE2 biosynthesis, and scavenging oxygen free radicals.

Animals↗
PubMed1997

Cantrell's syndrome in an infant.

Cantrell's syndrome is a rare combination of congenital midline thoracoabdominal defects and congenital heart disease. surgical repair can correct many of the anomalies. We report a neonate who presented with a short sternum, defective upper abdominal muscle, ectopic umbilicus, anterior diaphragmatic defect, ventricular septal defect and an intra-abdominal left ventricular diverticulum. Initially, the infant was treated with digoxin and diuretics for 5 months. Due to poor control of heart failure, one-stage surgical correction was performed with patch repair of the ventricular septal defect, ligation of left ventricular diverticulum and closure of the defects of the diaphragm and upper abdominal wall.

Abnormalities, Multiple↗
PubMed1997

Surgical experience with Salmonella-infected aneurysms of the abdominal aorta.

Five patients, aged between 64 and 75 years with Salmonella-infected abdominal aortic aneurysms were surgically treated between 1993 and 1995 at the National Cheng Kung University Hospital. Cultures of aneurysmal wall tissue and blood yielded Salmonella enteritidis Group B in three patients and Salmonella choleraesuis in the remaining two. All patients presented with fever and abdominal or back pain. Pulsatile masses were noted in only two patients. Infrarenal abdominal infected aneurysms were demonstrated by computed tomography and aortography in each patient. The five patients underwent aneurysmal resection with in situ graft reconstruction from 1 to 20 days after the diagnosis was made. The graft was wrapped with an omental pedicle. Duodenal repair was performed in one patient due to an aortoduodenal fistula found during surgery. He died 19 days after surgery because of duodenal leakage and uncontrolled sepsis. Four patients survived and remained well 11 to 34 months (mean, 25 mo) after surgery. Postoperatively, only one patient developed adhesion ileus and required enterolysis. Parenteral antimicrobial therapy was continued in all patients after surgery for 2 to 4 weeks; only one patient had an additional 4 months of oral antibiotics. Although the number of patients was small, the survival rate was high, at 80%. Our experience suggests that Salmonella-infected aneurysms of the abdominal aorta can be successfully treated by resection of the aneurysm with extensive debridement followed by in situ graft interposition with omentum wrapping. Once diagnosed, the patients should be scheduled for surgery as soon as possible. Antibiotics should be continued parenterally for at least 2 to 4 weeks postoperatively. While long-term suppressive antibiotic therapy is usually recommended, it might not be essential with our surgical approach.

Aged↗
PubMed1997

Thrombolytic therapy for mitral valve thrombosis.

A 44-year-old man with a St. Jude mitral valve was admitted because of progressive pulmonary edema. He was diagnosed with prosthetic heart valve thrombosis (PHVT) based on the findings of "muffled" prosthetic valve clicks. Doppler echocardiographic evidence of severe mitral stenosis and transesophageal echocardiographic evidence of limited mitral valve motility. Because the patient hesitated to undergo our recommended surgical treatment, he was immediately treated with intravenous recombinant tissue plasminogen activator (100 mg over 3 h) followed by heparinization. Two hours after the thrombolytic therapy, the prosthetic valve clicks became clearly audible and his congestive symptoms were dramatically improved. Follow-up echocardiography no longer-showed significant mitral valve obstruction. A transient cerebral ischemic attack occurred at the end of thrombolytic therapy but there were no neurologic sequalae. The patient, on warfarin therapy, was well at follow-up 8 months after discharge. Surgical intervention has long been the standard therapy for patients with PHVT. Our case experience suggests that thrombolytic therapy may be considered as an effective alternative to surgical intervention for selected patients with PHVT. In this report, we also review the current literature regarding the indications, effectiveness and safety of thrombolytic therapy in PHVT.

Adult↗
PubMed1997

Streptococcal toxic shock syndrome complicating varicella in children.

The most common complication in children with varicella is cutaneous superimposed infection with pyogenic bacteria. Group A beta-hemolytic streptococci, which are known to cause life-threatening infections in both previously healthy children and those with underlying diseases, are the most frequently associated pathogens. A newly recognized disease, called streptococcal toxic shock syndrome, is associated with severe morbidity and mortality. We report a 3-year-old boy with a diagnosis of this syndrome who presented with increasing fever, vomiting, and lethargy 7 days after the development of a classic varicella skin lesion. In spite of aggressive fluid supply, administration of inotropic agents, and cardiopulmonary resuscitation, a rapidly deteriorating clinical course led to death 4 hours after hospitalization. This is the first report of this association in Taiwan. Pediatricians evaluating children with varicella must be mindful of the potential for Group A beta-hemolytic streptococcal infection.

Chickenpox↗
PubMed1996

In vitro enhancement of antibody responses by T delta cells expressing IgD receptors.

Previous in vivo studies have shown that murine T cells induced to express receptors specific for IgD (IgD-R) have humoral immunoaugmenting properties with respect to both primary and secondary antibody responses to various antigens. Such murine IgD-R+ T cells (T delta cells) belong to the CD4+ T cell population in contrast with human T delta cells which also include CD8+ cells. The purpose of these studies was to develop an in vitro assay system to examine the mechanism by which T delta cells facilitate enhanced antibody responses. Our studies demonstrate that B cell responses to both soluble and particulate antigens can, indeed, be enhanced in vitro by coculture with T cells previously induced to express IgD-R. This in vitro effect requires cognate interaction between T and B cells and is dependent on the presence of adherent cells or IL-1. T cell priming with antigen, while not a prerequisite, was found to result in more effective T delta-B cell interactions compared with naive T delta cells. Finally, evidence was obtained in support of an adhesion-mediated T delta-B cell interaction since the immunoaugmenting properties of T cells expressing IgD-R are completely blocked by the addition of very low doses of monomeric IgD to the cultures.

Adjuvants, Immunologic↗
PubMed1996

Hepatitis C virus RNA in peripheral blood mononuclear cells: comparing acute and chronic hepatitis C virus infection.

Hepatitis C virus (HCV) can infect peripheral blood mononuclear cells (PBMC) of patients with chronic HCV infection. No data are available on PBMC testing for HCV RNA in acute hepatitis C. This study investigated the presence of HCV RNA in PBMC of patients with acute posttransfusion hepatitis C, compared with those with chronic HCV infection. Nested polymerase chain reaction (PCR) was applied to detect HCV RNA in 111 and 48 paired samples of serum and PBMC of 11 patients with acute posttransfusion hepatitis C and 48 patients with chronic HCV infection, respectively. In patients with acute posttransfusion hepatitis C, HCV RNA was detected in 17 of 29 (59%) and 67 of 82 (82%) serum samples collected during the incubation period and acute phase, respectively. Meanwhile, of the 48 patients with chronic HCV infection, 41 had serum HCV RNA (85%). HCV RNA was not detected in PBMC samples from incubation period or from acute-phase hepatitis, although it was detected in 12 of the 48 PBMC samples of chronically infected patients (25%) P < .005). Of the 12 PBMC specimens positive for positive-stranded HCV RNA, 6 were also positive for negative-stranded HCV RNA. Among patients with chronic HCV infection, HCV infection of PBMC was not related to age, sex, blood transfusion, serum alanine transaminase (ALT) levels, or serum virus titers. In conclusion, HCV infection of PBMC rarely exists in patients with acute hepatitis C. As HCV infection persists, the incidence of HCV infection of PBMC becomes higher.

Acute Disease↗