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Biomedical subjects

H S Lai

Publications and source records attributed to H S Lai.

At least 19 recordsLinked to original sources
PubMed2005

Calreticulin expression in neuroblastoma--a novel independent prognostic factor.

BACKGROUND: Calreticulin (CRT), an endoplasmic reticulum protein, has been reported to be essential for the differentiation of neuroblastoma (NB) cells, suggesting that CRT may affect the tumor behavior of neuroblastoma. The aim of this study was to evaluate the association of clinicopathologic factors and patient survival with the expression of CRT in patients with NB. PATIENTS AND METHODS: Sixty-eight NBs were investigated by immunohistochemical staining against CRT, and were divided into positive and negative immunostaining groups. Correlations between calreticulin expression, various clinicopathologic and biologic factors, and patient survival were studied. In seven tumor samples, CRT mRNAs and proteins were evaluated with real-time PCR and western blot, respectively, and correlated with immunohistochemical findings. RESULTS: Among 68 NBs, 32 (47.1%) showed positive CRT expression. Positive CRT immunostaining strongly correlated with differentiated histologies, as well as known favorable prognostic factors such as detected from mass screening, younger age (< or =1 year) at diagnosis and early clinical stages, but inversely correlated with MYCN amplification. Kaplan-Meier analysis revealed that NB patients with CRT expression did have better survival. Multivariate analysis demonstrated CRT expression to be an independent prognostic factor. Moreover, CRT expression also predicted better survival in patients with advanced-stage NBs, and its absence predicted poorer survival in patients whose tumor had no MYCN amplification. The amount of CRT mRNAs and proteins in NB tumor samples tested correlated well with the immunohistochemical expressions. CONCLUSIONS: CRT expression correlates with the differentiation of NB and predicts favorable survival, thereby suggesting CRT to be a useful indicator for planning treatment of NB.

Biomarkers, Tumor↗
PubMed2001

Complete genome sequence of an M1 strain of Streptococcus pyogenes.

The 1,852,442-bp sequence of an M1 strain of Streptococcus pyogenes, a Gram-positive pathogen, has been determined and contains 1,752 predicted protein-encoding genes. Approximately one-third of these genes have no identifiable function, with the remainder falling into previously characterized categories of known microbial function. Consistent with the observation that S. pyogenes is responsible for a wider variety of human disease than any other bacterial species, more than 40 putative virulence-associated genes have been identified. Additional genes have been identified that encode proteins likely associated with microbial "molecular mimicry" of host characteristics and involved in rheumatic fever or acute glomerulonephritis. The complete or partial sequence of four different bacteriophage genomes is also present, with each containing genes for one or more previously undiscovered superantigen-like proteins. These prophage-associated genes encode at least six potential virulence factors, emphasizing the importance of bacteriophages in horizontal gene transfer and a possible mechanism for generating new strains with increased pathogenic potential.

Bacteriophages↗
PubMed2001

Bacterial cholangitis in patients with biliary atresia: impact on short-term outcome.

Bacterial cholangitis (BC) is a common complication in patients with biliary atresia (BA) and is characterized by fever, acholic stools and positive blood cultures. The diagnosis is often empirical because the yield of blood cultures is low. It is difficult to differentiate BC from other febrile episodes. In order to characterize the clinical and laboratory features of BC in patients with BA, identify risk factors, and correlate cholangitis with outcome, 37 patients with BA from 1993 to 1998 who underwent a Kasai operation in our hospital were studied. The follow-up period ranged from 6 to 59 months. A total of 107 febrile episodes were documented in these patients. The diagnostic criteria for cholangitis were fever, increased jaundice, or acholic stools. The clinical features, laboratory data, results of bacterial cultures, and outcomes were analyzed retrospectively. A total of 107 febrile episodes, including 78 bouts of cholangitis and 29 non-cholangitis infections, were found in 34 patients. Patients with BC had higher postoperative bilirubin levels (P = 0.02) and less frequent use of prophylactic antibiotics (P = 0.05) than those with non-cholangitis infections. Abnormal white blood cell counts (> 12,000 or <4,000 mm3) tended to be present in patients with BC (P = 0.08). There were no statistical differences in the risk factors and laboratory data between culture-positive (n = 16) and -negative (n = 62) cholangitis cases. The occurrence of cholangitis significantly reduced survival in both patients with good (P = 0.03) and inadequate bile flow (P = 0.03). All 9 patients who had never had cholangitis survived during the follow-up period. Repeated attacks of BC further decreased survival probability. The responsive organisms were mainly enteric bacteria, including Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumanni, and Salmonella typhi. The sensitivity tests justified empirical therapy with ceftriaxone. The effectiveness of prophylactic trimethoprim-sulfamethoxazole or neomycin warrants further studies. BC was a highly prevalent postoperative complication in patients with BA, especially those with inadequate bile drainage. It significantly affected early mortality. Aggressive and complete treatment with empirical ceftriaxone was appropriate.

Bacterial Infections↗
PubMed2001

Prognostic indicators of survival in infants with congenital diaphragmatic hernia.

PURPOSE: This study sought to identify the factors predictive of the short-term outcome in infants with congenital diaphragmatic hernia (CDH). METHODS: We retrospectively reviewed medical records from September 1985 to December 1998 for all infants born with CDH and managed at National Taiwan University Hospital (NTUH). Coexisting pathology and measures of respiratory function were analyzed to determine the prognostic factors. RESULTS: A total of 32 infants with CDH were managed at NTUH over the past 13 years. The investigated factors associated with poor prognosis in CDH included congenital heart disease, chromosomal abnormality, pneumothorax, and preoperative parameters including arterial partial carbon dioxide pressure greater than 40 mmHg, arterial partial oxygen pressure less than 100 mmHg, alveolo-arterial partial oxygen pressure greater than 610 mmHg, and oxygen index (OI) greater than 0.4. Multiple logistic regression analyses indicated that only an OI greater than 0.4 and pneumothorax were significant indicators of poor prognosis. When the incidence of pneumothorax was compared between patients who received ventilation using a conventional mechanical ventilator or high-frequency oscillatory ventilator (HFOV), a trend toward a lower incidence of pneumothorax in those using HFOV for initial stabilization was found (p = 0.08). CONCLUSIONS: An OI greater than 0.4 before surgery and pneumothorax are poor prognostic indicators in infants with CDH. A high OI is reflective of the severity of pulmonary dysfunction in infants. Pneumothorax further compromises the dysfunction of a hypoplastic lung in infants with CDH. The results of this study show the importance of avoiding iatrogenic pneumothorax during management of infants with CDH.

Female↗
PubMed2001

Prediction of the outcome of pull-through surgery for Hirschsprung's disease using acetylcholinesterase activity.

BACKGROUND AND PURPOSE: Advances in surgical procedures for the treatment of Hirschsprung's disease have afforded the majority of patients a satisfactory outcome after definitive corrective surgery. However, some patients continue to have signs of persistent bowel dysfunction despite adequate resection of the aganglionic bowel segment. The definite etiology of persistent bowel dysfunction in these patients remains controversial. MATERIALS AND METHODS: The acetylcholinesterase activity in the proximal resection margin of pull-through surgical specimens collected from September 1992 to June 1998 was evaluated and correlated with clinical outcome. RESULTS: A total of 24 patients were studied, 15 males and 9 females. The follow-up period ranged from 1 year 7 months to 7 years 6 months. The Soave procedure was performed in 17 cases and the Duhamel in 7. Twenty cases had a good or fair clinical outcome and four (16.7%) had a poor outcome. There was no mortality. Among the 20 patients with a good or fair outcome, the acetylcholinesterase activity in the proximal section margins was not increased in 12, mildly increased in seven, and moderately increased in one. The four cases with poor outcome all had moderately increased acetylcholinesterase activity in at least one specimen. The association between moderately increased acetylcholinesterase activity and poor surgical outcome was significant (p = 0.0005). In contrast, there was no association between the surgical method (Soave or Duhamel) used and clinical outcome (p = 0.55). CONCLUSION: Acetylcholinesterase activity in the proximal resection margins of pull-through surgical specimens is a useful indicator for predicting the postoperative outcome in Hirschsprung's disease.

Acetylcholinesterase↗
PubMed2000

Free radical scavenging activity of fullerenol on the ischemia-reperfusion intestine in dogs.

Fullerenol, a water-soluble C(60)-fullerene derivative, has been demonstrated to have the capability to scavenge free radicals in vitro and in vivo. The purpose of this study was to investigate whether fullerenol can scavenge the free radicals that are massively induced during ischemia-reperfusion (I/R) injury of the small intestine, either preventively or therapeutically. Clamping the superior mesenteric artery and vein for 60 minutes to induce I/R injury was performed on male mongrel dogs. Thirty dogs were divided into three groups (10 in each): The control (C) group received no medication; the preventive (P) group received fullerenol (1 mg/kg) intravenously 30 minutes before ischemia; the therapeutic (T) group received the same dose of fullerenol immediately after reperfusion. This study was an experimental randomized trial. Intestinal segments were obtained 10, 20, 30, and 60 minutes after reperfusion; and blood samples and specimens of major organs were taken 60 minutes after reperfusion. Concentrations of lipid peroxidation products, including conjugated diene (CD) and malondialdehyde (MDA), and the level of glutathione (GSH) in intestinal tissue were determined. Serum indicators of liver and renal function were measured. Histologic examination of the small intestine and major organs were also performed. A significant increase in intestinal MDA and CD contents was detected at 30 and 60 minutes after reperfusion. The tissue GSH content, in contrast, was decreased 60 minutes after reperfusion. Administration of fullerenol diminished these changes both preventively and therapeutically. Liver and renal functions were within normal limits in all groups. Moreover no obvious histopathologic additional damage could be found in either the P or the T group. It is suggested that fullerenol can be considered a powerful scavenger for the free radicals induced by I/R injury of the small intestine.

Alanine Transaminase↗
PubMed2000

Focal nodular hyperplasia of the liver in a child.

We present a case of focal nodular hyperplasia (FNH) of the liver in a 7-year-old girl. The hepatic tumor was found incidentally on physical examination at school. During surgery, a hypervascular mass with a nodular surface was found to be confined to the right lobe of the liver (mainly in segments 5 and 6). The brownish tumor and the gallbladder were completely removed. Pathologic examination revealed a 10 x 9 x 5-cm mass with a central scar and radiating septa, consistent with the diagnosis of FNH. The postoperative course was complicated by subhepatic effusion, which was resolved by percutaneous computed tomography-guided drainage. She remained well 2 years after surgery.

Child↗
PubMed1999

Changes of serum and urinary neopterin concentrations in rats after partial hepatectomy.

OBJECTIVE: To investigate the changes in serum and urinary neopterin concentrations over time after partial hepatectomy in rats, and to find out if neopterin can be used as a marker of immunological response during the regulation of liver regeneration. DESIGN: Randomised experiment. SETTING: University hospital, Taiwan, R.O.C. SUBJECTS: 84 male Wistar rats weighing about 200g. INTERVENTIONS: Partial hepatectomy (67%) or sham operation (n = 42 in each group). MAIN OUTCOME MEASURES: Serum and urinary neopterin concentrations measured by radioimmunoassay preoperatively and on days 1, 2, 3, 5, 7, and 10 postoperatively. RESULTS: Serum neopterin concentrations increased and reached their peak on days 5 and 7 after partial hepatectomy. The urinary neopterin concentration showed a similar trend, but with a more pronounced increase on days 5 and 7. CONCLUSIONS: Serum and urinary neopterin concentrations can be used as markers of activated cell-mediated immunity in rats after partial hepatectomy.

Animals↗
PubMed1998

Carnitine contents in remnant liver, kidney, and skeletal muscle after partial hepatectomy in rats: randomized trial.

Carnitine, an important carrier of free fatty acid that is transported into mitochondria for beta-oxidation, was thought to be one of the key factors in the regulation of liver regeneration. If the carnitine content is insufficient in the hepatocyte, it might impair the energy substrate's transport and the energy charge required for cell regeneration. The purpose of this study is to evaluate the changes of carnitine content in remnant liver, kidney, and skeletal muscle simultaneously after partial hepatectomy in rats. Partial hepatectomy with resection of the median and left lateral lobes was performed on male Wistar rats. Rats with a sham operation comprised a control group. This study was an experimental randomized trial. Ten rats from each group were sacrificed before the operation and at 6, 24, 48, and 72 hours after the operation. The carnitine content, as total and free forms, in remnant liver, kidney, and skeletal muscle were quantified by high-performance liquid chromatography. The carnitine contents in the remnant liver increased significantly at 6, 24, and 48 hours after partial hepatectomy (p < 0.01). The increase of total carnitine content was more obvious than that of the free form. In contrast, the decreasing concentrations of total carnitine and free carnitine in the kidney were significant (p < 0.01). In skeletal muscle the total carnitine content decreased to a small extent, and it was observed only at 6 hours after partial hepatectomy (p < 0.05). It is suggested that remnant liver promoted the generation of carnitine, whereas kidney and skeletal muscle released their stored carnitine at an early stage after partial hepatectomy. As a result, the influx of the carnitine into hepatocytes increased at the regenerative stage. The carnitine content of remnant liver is sufficient during the early posthepatectomy stage.

Animals↗
PubMed1998

Hepatocellular carcinoma in children: clinical review and comparison with adult cases.

BACKGROUND: Hepatocellular carcinoma (HCC) in children was rarely reported and usually included with hepatoblastoma in most studies of pediatric liver malignancies despite different clinical behaviors. The authors report their experience in pediatric HCC and discuss its differences from adult HCC. METHODS: A retrospective review of radiographic, laboratory, pathological, and therapeutic data in 55 children with HCC was performed. The liver function was graded by modified Child's classification. Kaplan-Meier survival curves in various therapeutic and Child's groups were plotted, and log-rank test was used to detect differences among survival curves. RESULTS: Although children with HCC mostly presented with advanced disease at diagnosis, disturbances of liver function were unremarkable. Sixty-eight percent of cases concurred with liver cirrhosis. The median survivals for resectable, chemotherapeutic, and untreated HCCs were 23, 3, and 2 months, respectively. Resectable HCC significantly posed a much better prognosis. However, the resectability was unsatisfactory (18.2%). Resection was limited because of anatomic unfeasibility including bilateral involvement (62.5%), portal vein thrombi (41.7%), distant metastasis (29.1%), para-aortic lymphadenopathy (18.8%), inferior vena cava thrombi (16.7%), and hilar invasion (6.3%). Distant metastasis was the most ominous for survival in children with unresectable HCC. CONCLUSIONS: HCC behaved somewhat differently between children and adults. Surgical resection represented the best hope of long-term survival. The outcome in children could not keep up with that in adults because of a diagnostic delay. Hence, alpha-fetoprotein and sonography screening in carrier children should be worthwhile.

Adolescent↗
PubMed1998

Viral etiology of intussusception in Taiwanese childhood.

BACKGROUND: Adenovirus infection and lymphoid hyperplasia have been associated with childhood intussusception. However, the extent of other viruses involved in this condition remains unclear. This prospective study investigates the relationship between some lymphotropic viruses and current childhood intussusception. METHODS: Patients with intussusception encountered in a pediatric emergency department in a recent 3-year period were studied. Healthy infants and toddlers of comparable age served as controls. Throat and rectal viral cultures were performed in patients and controls. Viral antibodies against adenovirus, cytomegalovirus, human herpesvirus (HHV)-6, HHV-7 and Epstein-Barr virus (EBV) were tested in paired sera from the patients. Acute stage serum from each patient and mesenteric lymph nodes from patients requiring surgery were studied for the presence of adenovirus genome by PCR. RESULTS: Twenty-seven of 61 (44.3%) intussusception patients, but only 2 of 52 (3.8%) healthy controls shed nonenteric adenovirus in throat and rectal specimens (P < 0.001). Of the 27 (74.1%) patients who shed adenovirus, 20 were older than 1 year old, whereas only 1 of 15 (6.7%) similarly aged patients in a previous study from the same area three decades ago did so (P = 0.001). Among 43 patients with available paired sera, acute primary viral infection was found in 17 (39.5%) by adenovirus, 4 (9.3%) by HHV-6, 5 (11.6%) by HHV-7, 2 (4.7%) by EBV and none by cytomegalovirus. Multiple viral infections occurred in 6 patients. Adenovirus genome was detected in 4 of 9 mesenteric lymph nodes and in only 3 of 60 (5%) acute phase sera. CONCLUSIONS: Primary nonenteric adenovirus infection contributes to current childhood intussusception. Acute primary HHV-6, HHV-7 and EBV infections also play etiologic roles.

Acute-Phase Reaction↗
PubMed1998

Role of thermography in the diagnosis of undescended testes.

OBJECTIVES: The location of an undescended testis is important for the choice of therapy. Ultrasonography cannot serve as a stand-alone screening method in the management of the undescended testis because of its limited sensitivity and accuracy. The aim of this study was to clarify the diagnostic value of thermography in the patients with undescended testes. METHODS: We evaluated prospectively 28 patients with 36 undescended testes from January 1995 to December 1996. The patients' ages ranged from 16 to 39 months with a mean age of 26.3 +/- 8.2 months. In addition to physical palpation by a pediatric surgeon, ultrasonography and thermography were performed for screening the locations of retained testes. RESULTS: The diagnostic rates were 63.9% (23/36) by palpation, 65.7% (23/35) by ultrasonography and 54.5% (18/33) by thermography. The results of the three diagnostic methods showed no significant difference by Fisher's exact test. Of the 17 higher located testes (inguinal canal and above external ring) 7 were palpable, 8 were identified by ultrasonography, 10 were detected by thermography. Of the 7 nonpalpable testes and testes not detected by ultrasonography, 5, including 2 intra-abdominal testes, were identified by thermography. CONCLUSION: It is suggested that thermography can play a role in locating high undescended testes which are nonpalpable and not detected by ultrasonography.

Child, Preschool↗
PubMed1998

Tissue plasminogen activator reduces intraperitoneal adhesion after intestinal resection in rats.

We investigated whether tissue plasminogen activator (tPA), a plasma serine protease that catalyzes the initial and rate-limiting step in fibrinolysis, inhibits postoperative intraperitoneal adhesion formation in rats. Male Wistar rats weighing 200 to 250 g underwent laparotomy with a 15-cm intestinal resection and reanastomosis; the intestinal serosa was scratched to induce adhesion formation. The rats were divided into three groups: the control group received no medication; the normal saline group received peritoneal irrigation with 6 mL normal saline intraoperatively; and the tPA group received peritoneal irrigation with 6 mL tPA solution (5 mg/L) intraoperatively. The rats were killed 7 or 14 days later. The scores (severity of adhesion, 0-3 point scale), strength, and extent of fibrous bands were recorded on the day the rats were killed. Wound strength was measured using an Instron tensionmeter immediately after the rats were killed. The concentrations of plasma tPA and plasminogen activator inhibitor (PAI)-1 and -2 were measured. The scores and strength of fibrous bands in the tPA group were lower than those in the control and saline groups whereas wound strength was similar in all groups. The plasma tPA concentration was significantly higher and the plasma PAI-1 and PAI-2 concentrations were significantly lower in the tPA group than in the control and saline groups on the 7th and 14th postoperative days. Our findings suggest that tPA can reduce the incidence of postoperative intraperitoneal adhesions without impairing wound healing.

Animals↗