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Biomedical subjects

C S Huang

Publications and source records attributed to C S Huang.

At least 19 recordsLinked to original sources
PubMed2007

B-group vitamins, MTHFR C677T polymorphism and carotid intima-media thickness in clinically healthy subjects.

OBJECTIVE: Plasma B-group vitamins and age may affect the carotid intima-media thickness (IMT) in subjects with different 677TT genotype of the methylenetetrahydrofolate reductase (MTHFR) gene. DESIGN: A hospital-based cross-study. SETTING: Genomic and Vascular Center, Changhua Christian Hospital, Changhua, Taiwan. SUBJECTS: Five hundred and forty-one clinically healthy subjects. INTERVENTION: Fasting plasma, homocysteine (Hcy), vitamin B(6), vitamin B(12), folate and B-mode carotid ultrasound. RESULTS: MTHFR genotype, plasma concentrations of folate, vitamin B(6) and vitamin B(12) and age were significantly correlated to the plasma Hcy concentration. MTHFR 677TT carriers had higher concentrations of Hcy than did subjects with the CC and CT genotypes. Age, sex, body mass index and plasma Hcy were independent contributors to increase carotid IMT. However, with stratification by mean value of age and B-group vitamins concentrations, we found that at advanced age, lower plasma folate and vitamin B(12) were three risk factors involved in the enhancing effect of the MTHFR 677TT genotype on the increase of plasma Hcy and carotid IMT. CONCLUSION: MTHFR 677TT-related carotid atherosclerosis was only identified in healthy elderly subjects with lower level of plasma folate and vitamin B(12). SPONSORSHIP: Changhua Christian Hospital.

Adult↗
PubMed2006

Non-traumatic colon perforation in children: a 10-year review.

Colon perforation is an abdominal surgical emergency in the pediatric population, but is seldom reported when occurring from non-traumatic causes in children beyond the neonate. The goal of this study was to identify the clinical characteristics, management, and outcomes of non-traumatic colon perforation in children. Medical records for the 10-year period from September 1994 to September 2004 were reviewed for children beyond the neonate with non-traumatic colon perforation. Data gathered included age, gender, symptoms, duration of symptoms, physical findings, and length of postoperative hospital stay. Diagnostic information included laboratory data, radiographic imaging, and operative findings. Forty-four patients with non-traumatic colon perforation were recruited into this study. The mean age was 2.22 +/- 1.87 years; 91.4% of cases were younger than 5 years old. The most common presenting symptom was fever (97.7%); the most common sign was abdominal distention (93.1%). The mean duration of symptoms prior to admission was 6.19 days. Pneumoperitoneum was presented in 86.3% of patients by plain abdominal radiograph. Ascending and transverse colon were the most common perforation sites. Non-typhoid salmonella was the leading pathogen isolated, causing 20.4% of episodes. One case died due to Clostridium speticum infection. Non-traumatic colon perforation most commonly affects children younger than 5 years of age. It may be secondary to infection, especially non-typhoid salmonella. Plain abdominal radiograph can be an adjuvant tool for the high index of suspicion for colon perforation in children with abdominal distention and history of fever or diarrhea for more than 5 days.

Abdomen, Acute↗
PubMed2005

Prolene hernia system compared with mesh plug technique: a prospective study of short- to mid-term outcomes in primary groin hernia repair.

Two types of anterior tension-free hernioplasty, prolene hernia system (PHS) repair and mesh plug technique (MPT), were introduced to Taiwan in 2001. This study compared the short- to mid-term outcomes following primary groin hernia repair with PHS and MPT. From January 2001 to December 2003, 393 patients with 426 primary groin hernias were operated on by a single surgeon using MPT (n=192) and PHS (n=234). Baseline perioperative details and follow-up information were compared. Demographic characteristics of both groups were similar. The laterality, types of anesthesia, postoperative stay, postoperative wound pain scores, wound complications and days to return to activities of daily life were equally distributed between the two groups. However, the distribution of Gilbert types in the PHS group was shifted a little to the right compared with that of the MPT group. PHS repair had longer operative time (34+/-17 vs 25+/-9 minutes, p<0.01). No recurrence was noted in both groups during the follow-up from 5 to 41 months. Chronic non-disabling groin pains were noted in 2.8% (6/218) of patients in the PHS group and 8.9% (14/175) in the MPT group (p=0.01). Our results show that both PHS and MPT repairs can be performed with short operation time, minor wound pain and quick return to activities of daily life without short- to mid-term recurrences, but postoperatively the MPT group had higher incidence of chronic non-disabling groin pain. Although the MPT is less invasive, the additional protective patch in the preperitoneal space of the PHS may provide a further safeguard against recurrences, especially for those patients with attenuated inguinal floor. Long-term follow-up is needed.

Adolescent↗
PubMed2003

Long-term results of major bile duct injury associated with laparoscopic cholecystectomy.

BACKGROUND: Major bile duct injury (MBDI) is the most serious complication associated with laparoscopic cholecystectomy (LC). This study reports on long-term outcomes and clinical factors which predicted the outcome of 25 patients with LC-associated MBDI. METHODS: Twenty-five consecutive patients receiving either primary (n = 11) or redo (n = 14) biliary reconstructive surgery at Cathay General Hospital for LC-associated MBDI were prospectively followed for 2 to 10 (mean, 4.5) years to assess their long-term outcomes. Twelve clinical factors relevant to their outcomes were analyzed. RESULTS: There was no mortality. Although the 1-year postoperative results were successful in 23 patients (92%), the mid- to long-term outcomes were successful in only 17 patients (68%). Eight patients (32%) developed biliary strictures at an average of 3.3 years postoperatively and required subsequent reoperation or biliary stenting. Statistical comparison of 12 risk factors between the successful and unsuccessful groups revealed that two were significant, namely, repair performed by a nonreferral surgeon (p = 0.02) and repair at a stage with recent active inflammation (p = 0.04). A serum alkaline phosphatase level greater than 400 IU in the sixth postoperative month was highly correlated with long-term nonsuccess (p = 0.01). CONCLUSIONS: Only 68% of patients with LC-associated MBDI who underwent reconstructive surgery at our institution had long-term success. A serum alkaline phosphatase level above 400 IU in the sixth postoperative month was predictive of nonsuccess. For better long-term results, repair should be performed by the referral surgeon at a stage without coexisting active inflammation.

Adult↗
PubMed2002

Scavenging property of three cresol isomers against H2O2, hypochlorite, superoxide and hydroxyl radicals.

Formocresol has long been used for pulpotomy of primary teeth and as an intracanal medicament. Little is known, however, about the pharmacological effect of tricresols. This study showed that three cresol isomers, o-cresol, m-cresol and p-cresol, are H2O2 scavengers with a 50% inhibitory concentration (IC50) of 502, 6.7 and 10.16 microM, respectively. o-, m- and p-cresol were also shown to be effective scavengers of superoxide radicals generated by xanthine/xanthine oxidase with an IC50 of 282, 153 and > 4000 microM, respectively, as analyzed by luminometer. o-, m- and p-cresol showed protective effects on the DNA breaks generated by H2O2/FeCl2 and FeCl3/ascorbate/H2O2 systems at concentrations ranging from 70 microM to 1.43 mM, o-, m- and p-cresol also showed differential protective effects against DNA breaks induced by 0.17% NaOCl with 100% inhibitory concentration (IC100) of about 10, 1 and 10 mM, respectively. In addition, reaction with 3% H2O2 and 0.17% NaOCl completely prevented NaOCl-induced DNA breaks. The results indicate that the three cresol isomers are effective ROS scavengers and may prevent ROS induced damage when used as pulpotomy agents or as intracanal medicaments. Owing to the difference in the position of the functional hydroxyl group in the three cresol isomers, m-cresol is the most effective ROS scavenger. Concomitant use of H2O2 for root canal irrigation may diminish both the tissue dissolving capacity of NaOCl and NaOCl-induced DNA damage.

Acridines↗
PubMed2001

Cooperative binding of gamma-glutamyl substrate to human glutathione synthetase.

Human glutathione synthetase is responsible for catalyzing the final step in glutathione biosynthesis. It is a homodimer with a monomer subunit MW of 52 kDa. Kinetic analysis reveals a departure from linearity of the Lineweaver-Burk double reciprocal plot for the binding of gamma-glutamyl substrate, indicating cooperative binding. The measured apparent K(m) values for gamma-glutamyl-alpha-aminobutyrate (an analog of gamma-glutamyl-alpha-aminobutyrate) are 63 and 164 microM, respectively. Neither ATP (K(m) of 248 microM) nor glycine (K(m) of 452 microM) exhibits such cooperative binding behavior. Although ATP is proposed to play a key role in the sequential binding of gamma-glutamyl substrate to the enzyme, the cooperative binding of the gamma-glutamyl substrate is not affected by alterations of ATP concentration. Quantitative analysis of the kinetic results for gamma-glutamyl substrate binding gives a Hill coefficient (h) of 0.75, indicating negative cooperativity. Our studies, for the first time, show that human glutathione synthetase is an allosteric enzyme with cooperative binding for gamma-glutamyl substrate.

Adenosine Triphosphate↗
PubMed2001

Mechanisms of inactivation of E-cadherin in breast carcinoma: modification of the two-hit hypothesis of tumor suppressor gene.

Loss of heterozygosity (LOH) allows the expression of recessive mutation in tumor suppressor genes (TSG). Therefore, on the basis of Knudson's 'two-hit' hypothesis for TSG inactivation, the detection of a high LOH frequency in a chromosomal region is considered critical for TSG localization. One of these LOH regions in breast cancer is 16q22.1, which has been suggested to reflect the involvement of E-cadherin (E-cad), a cell-cell adhesion molecule. To confirm the tumorigenic role of E-cad, 81 sporadic invasive ductal carcinomas (IDCs) of the breast were tested for the 'two hits' required to inactivate this gene. A high frequency (37.3%) of LOH was detected in 67 informative tumors, but no mutation was found. To examine the possibility that transcriptional mechanisms serve as the second hit in tumors with LOH, specific pathways, including genetic variant and hypermethylation at the promoter region and abnormal expression of positive (WT1) and negative (Snail) transcription factors, were identified. Of these, promoter hypermethylation and increased expression of Snail were found to be common (>35%), and to be strongly associated with reduced/negative E-cad expression (P<0.05). However, unexpectedly, a significantly negative association was found between the existence of LOH and promoter hypermethylation (P<0.05), which contradicts the 'two-hit' model. Instead, since they coexisted in a high frequency of tumors, hypermethylation may work in concert with increased Snail to inactivate E-cad expression. Given that E-cad is involved in diverse mechanisms, loss of which is beneficial for tumors to invade but may also trigger apoptosis, this study suggests that maintaining a reversible mechanism, either by controlling the gene at the transcriptional level or by retaining an intact allele subsequent to LOH, might be important for E-cad in IDC and may also be common in TSGs possessing diverse functions. These findings provide clues to explain why certain TSGs identified by LOH cannot fulfil the two-hit hypothesis.

Adaptor Proteins, Signal Transducing↗
PubMed2001

Distinguishing two types of gray mullet, Mugil cephalus L. (Mugiliformes: Mugilidae), by using glucose-6-phosphate isomerase (GPI) allozymes with special reference to enzyme activities.

The resident and migratory types of gray mullet, Mugil cephalus, on the coast of Taiwan can not be separated morphologically. Allozyme analysis was applied to estimate genetic variation between the two types of gray mullet and to test whether they belong to different populations. After starch gel electrophoresis, different allelic frequency spectra of glucose-6-phosphate isomerase-A (GPI-A) between stocks was observed. The resident stock contained Gpi-A(135) and Gpi-A(100), whereas the migratory type contained Gpi-A(100) only. In addition, GPI activities of locus A showed two distinct profiles between the two alleles. The results broadly revealed that Gpi-A allelic frequency was not regulated by temperature changes even after 6 months of thermal acclimation. This suggests that natural selection may play a role in shaping the allelic frequency change during the migratory journey. These findings suggest that the Gpi-A allelic difference can be used for population discrimination.

Acclimatization↗
PubMed2001

Use of pulsed-field gel electrophoresis to investigate an outbreak of Serratia marcescens infection in a neonatal intensive care unit.

Serratia marcescens is a well-recognized hospital-acquired pathogen, which has been associated with a number of specific outbreaks, particularly in critically ill neonates. We used pulsed-field gel electrophoresis (PEGE) typing to analyse an outbreak in a neonatal intensive care unit (NICU). We included samples from nine patients, three handwashes and ten environmental isolates from an outbreak (February to August 1999) in addition to four patient isolates from different wards of our hospital during the same time period. The clinical presentations of the outbreak included bacteraemia (four cases), pneumonia (three cases), umbilical wound infection (one case) and conjunctivitis (one case). Nine outbreak isolates exhibited an identical PFGE fingerprint, while the epidemiologically unrelated strains demonstrated distinct patterns. Epidemiological investigation failed to reveal a common source of the outbreak, although the epidemic S. marcescens strain was isolated from hand-washes and doors of incubators. We concluded that cross-transmission via transient contamination of hands was the major route for this outbreak. Strict handwashing practices, the cohorting and isolation of colonized and infected patients, and the regular dis-infection of incubators are crucial steps for preventing the transmission of S. marcescens in an NICU. This PFGE method is highly discriminatory for the thorough epidemiological investigation of an outbreak of S. marcescens.

Cross Infection↗
PubMed2001

Surgical implications of pseudomonas aeruginosa necrotizing fasciitis in a child with acute lymphoblastic leukemia.

Necrotizing fasciitis caused by Pseudomonas aeruginosa is extremely rare. Only 4 cases were reported in the literature. The authors report the occurrence of P aeruginosa necrotizing fasciitis starting out as a vulval abscess in a girl before induction chemotherapy for acute lymphoblastic leukemia. To our knowledge, this is the second case described in association with leukemia. In this case, the outcome was favorable because of early surgical intervention, confirming the diagnosis. J Pediatr Surg 36:948-950.

Child, Preschool↗
PubMed2001

Nickel-titanium mandibular bonded lingual 3-3 retainer: for permanent retention and solving relapse of mandibular anterior crowding.

An innovative technique that involves a nickel-titanium mandibular bonded lingual 3-3 retainer was used to treat relapse of mandibular anterior crowding. The purpose of this study was to demonstrate clinical procedures and to study the effects of a new mandibular bonded lingual 3-3 retainer on the mandibular dental arch. In 18 patients, changes in the irregularity index and in arch dimensions (intercanine width, arch length, and arch depth) were measured against the patients' mandibular dental casts, which were obtained at completion of the previous orthodontic treatment (T(0)). These measurements were taken at the beginning of retreatment (T(1)), and 2 (T(2)), 4 (T(3)), and 6 (T(4)) months after initiation of retreatment. During the period of relapse (T(0)-T(1)), the irregularity index increased from 1.3 to 3.5 mm and the mandibular arch dimensions decreased. Four months after a segment of.018-in nickel-titanium archwire was bonded lingually from canine to canine, the irregularity index decreased from 3.5 to 1.0 mm and the arch dimensions increased and recovered their original posttreatment dimensions. The nickel-titanium archwire was left in place for permanent retention after the period of retreatment. This simple technique effectively solved relapse of mandibular anterior crowding in 4 months. This mandibular bonded lingual 3-3 retainer could be used both actively, to re-treat mandibular anterior crowding without the use of lingual brackets, and passively, for maintenance as a bonded lingual retainer.

Adolescent↗
PubMed2001

Role of laparoscopic cholecystectomy in the management of polypoid lesions of the gallbladder.

This retrospective clinicohistopathologic study was performed to delineate the role of laparoscopic cholecystectomy in the management of polypoid lesions of the gallbladder. One hundred forty-three consecutive patients who had a preoperative sonographic diagnosis of polypoid lesions of the gallbladder with a diameter less than 1.5 cm and who underwent laparoscopic cholecystectomy at Cathay General Hospital were included in the analysis. Histopathologic study showed that 22 (15.4%) patients had true tumors, including adenoma (16), adenoma with focal adenocarcinoma (2), adenocarcinoma (3), and carcinoid tumor (1). Tumorlike lesions were found in 121 (84.6%) patients and included cholesterol polyp (106), adenomyomatous hyperplasia (10), inflammatory polyp (3), and papillary hyperplasia (2). The mean diameter of malignant polypoid lesions of the gallbladder was 1.35 +/- 0.42 cm, which was significantly larger than that of cholesterol polyps (0.66 +/- 0.40 cm, P = 0.0001) but not significantly larger than that of adenomyomatous hyperplasias (1.12 +/- 0.42 cm) and adenomas (1.08 +/- 0.47 cm). The mean age of patients with malignant polypoid lesions of the gallbladder (61.2 +/- 13.3 years old) was significantly older than that of patients with adenomyomatous hyperplasia (46.6 +/- 13.4 years, P = 0.03), cholesterol polyps (44.5 +/- 10.5 years, P = 0.0003), and adenomas (41.4 +/- 9.4 years, P = 0.0008). Clinical follow-up showed that most (98.6%) patients benefited from the minimal invasiveness of laparoscopic cholecystectomy with satisfactory surgical results. We conclude that laparoscopic cholecystectomy is a reliable, safe, and minimally invasive biopsy procedure and definite management of polypoid lesions of the gallbladder with a diameter less than 1.5 cm.

Adult↗
PubMed2001

Breast cancer screening in Taiwan and China.

In contrast to incidence rates prevailing in women in Western countries, Chinese women in Taiwan and China are considered to have the lowest incidence of breast cancer in the world. However, in the past 20 years, breast cancer incidence in Chinese women has seen a dramatic increase of 50-100%, which strongly supports the need for breast cancer prevention and screening programs. It is also important to indicate that breast cancer in Chinese women is characterized by younger age at tumor onset. More than 50% of the total breast cancer diagnosed annually is found in premenopausal patients, creating the need to initiate breast cancer screening programs in this population. Initially, the breast cancer screening program depended on breast self-examination. Since Chinese women have relatively small breasts, it was assumed that breast cancer was easier to detect by self-examination. However, this strategy has failed. The dilemma of breast cancer screening can be summarized by the fact that Chinese have a rapidly increasing incidence of premenopausal breast cancer, while the overall incidence is still low. Therefore, since premenopausal women have denser breasts than postmenopausal women, and Chinese women have smaller breasts and a higher percentage of dense breasts, increased mammography screening frequency may be not the sole solution to increase detection in this age group. In our experience in Taiwan, the addition of breast ultrasound may be helpful. Nearly all the nonpalpable cancers detected by mammography in our women are due to microcalcifications, and ultrasound is more sensitive in detecting nonpalpable cancers; Therefore, we suggest that a screening program, based on ultrasound to detect nonpalpable cancers not associated with microcalcifications, along with mammography within a long period, may provide more effective protection for Taiwanese and Chinese women against breast cancer.

Journal Article↗
PubMed2000

Novel kinetics of mammalian glutathione synthetase: characterization of gamma-glutamyl substrate cooperative binding.

Glutathione (GSH) synthetase [L-gamma-glutamyl-L-cysteinyl:glycine ligase (ADP-forming), EC 6.3.2.3] catalyzes the final step in GSH biosynthesis. Mammalian glutathione synthetase is a homodimer with each subunit containing an active site. We report the detailed kinetic data for purified recombinant rat glutathione synthetase. It has the highest specific activity (11 micromol/min/mg) reported for any mammalian glutathione synthetase. The apparent K(m) values for ATP and glycine are 37 and 913 microM, respectively. The Lineweaver-Burk double reciprocal plot for gamma-glutamyl substrate binding revealed a departure from linearity indicating cooperative binding. Quantitative analysis of the kinetic results for gamma-glutamyl substrate binding gives a Hill coefficient (h) of 0. 576, which shows the negative cooperativity. Neither ATP, the other substrate involved in forming the enzyme-bound gamma-glutamyl phosphate intermediate, nor glycine, which attacks this intermediate to form GSH, exhibit any cooperativity. The cooperative binding of gamma-glutamyl substrate is not affected by ATP concentration. Thus, mammalian glutathione synthetase is an allosteric enzyme.

Animals↗
PubMed2000

Genome-wide search for loss of heterozygosity using laser capture microdissected tissue of breast carcinoma: an implication for mutator phenotype and breast cancer pathogenesis.

Breast cancer is considered to display a high degree of intratumor heterogeneity, without any obvious morphological and pathological steps to define sequential evolution, and its progression may vary among individual tumors. In an attempt to elucidate these etiological and phenotypic complexities, the present study, based on the fundamental concept that genomic instability is the engine of both tumor progression and tumor heterogeneity, was conducted to test the hypothesis that breast cancer pathogenesis is driven by double-strand break (DSB)-initiated chromosome instability (CIN). The rationale underlying this hypothesis is derived from the clues provided by family breast cancer syndromes, in which susceptibility genes, including p53, ATM, BRCA1 and BRCA2, are involved within the common functional pathway of DSB-related checkpoint/ repair. Because genomic deletion caused by DSB is reflected in the genetic mechanism of loss of heterozygosity (LOH), this genome-wide LOH study was conducted, using 100 tumors and 400 microsatellite markers. To minimize the effect of heterogeneity within tumors, the experimental technique of laser capture microdissection was used to ensure that genetic and phenotypic examinations were based on the same tumor cells. Support for our hypothesis comes from the observations that: (a) the extent of DSB-initiated CIN in tumors significantly increased as tumors progressed to poorer grades or later stages; (b) in the sequential steps toward CIN, the loci of p53 and ATM, the key checkpoint genes against DSB, were lost at the earliest stage; and (c) many loci identified to be important in breast tumorigenesis were the genomic sites possibly harboring the genes involved in DSB-related checkpoint/repair (including RAD51, RAD52, and BRCA1) or CIN (including FA-A, FA-D, and WRN), and a higher number of these loci showing LOH was significantly associated with increased level of DSB-initiated CIN (P < 0.0001). Breast cancers are thus considered to be sequentially progressive with CIN. However, CIN might also cause genetic heterogeneity, which was revealed by the findings that LOH at some markers was observed only in the component of ductal carcinoma in situ but not in the invasive component of the same tumors. In addition, some markers were found to preferentially lose at specific tumor grades, implying their contribution to genetic heterogeneity during tumor development. Therefore, this study suggests that breast cancer progression is clonal with regard to CIN, but different breast cancers would present distinct molecular profiles resulting from genetic heterogeneity caused by CIN.

Adult↗
PubMed2000

Activity of p44/42 MAP kinase in the caudal subnucleus of trigeminal spinal nucleus is increased following perioral noxious stimulation in the mouse.

The extracellular signal-regulated protein kinase-1 and -2 (ERK1 and ERK2), also referred to as the p44/42 mitogen-activated protein kinase (p44/42 MAP kinase), plays an essential role in neuronal signal transduction, but its function involved in nociceptive response has not been deeply studied yet. Here we report immunohistochemical evidence that p44/42 MAPK might be critical in nociceptive response. We found that after formalin was injected into the perioral skin of the upper lip of mice, the number of activated p44/42 MAPK-like immunoreactive neurons was significantly increased in the laminae I and II of the caudal subnucleus of the trigeminal spinal nucleus (Sp5C). The positive neurons and fibers were mostly concentrated in the middle portion of Sp5C dorsoventrally, where the afferent fibers innervating the skin of the upper lip are terminated. The reactive products were localized in perikarya, dendrites, nuclei, and diffusely in the neuropil. The present result suggests that p44/42 MAPK may be important in the transmission and modulation of noxious information in Sp5C.

Animals↗
PubMed2000

Changes in portal venous hemodynamics in patients with severe acute hepatitis over one year.

PURPOSE: A wide range of portal vein blood flow velocity (PVV) values can be found in acute hepatitis. We studied course and medical significance of PVV changes in patients with severe acute hepatitis over a 1-year period. METHODS: Portal venous hemodynamics were studied by Doppler sonography in 90 patients at study enrollment and 3, 6, and 12 months following an episode of severe acute hepatitis. RESULTS: Forty-one survivors who had a maximum PVV at enrollment greater than or equal to the value measured at the third month were classified as the "declining PVV" group. Thirty-six survivors who had a maximum PVV at enrollment less than the value measured at the third month were classified as the "rising PVV" group. Thirteen patients died of acute hepatic failure and were classified as the fatality group. The fatality group had significantly lower maximum PVV, worse liver biochemical test results, and a higher prevalence of ascites at enrollment. In contrast, the declining PVV group showed significantly better liver biochemical test results and a lower prevalence of ascites. There was no significant difference in portal vein blood flow between the rising and declining PVV groups since portal vein diameter increased while PVV decreased. CONCLUSIONS: An initially decreased PVV can be found in some patients with severe acute hepatitis and is inversely correlated with the severity of liver damage.

Acute Disease↗