Search PubMed⌕ Search

Biomedical subjects

C C Wang

Publications and source records attributed to C C Wang.

At least 271 records · Page 15Linked to original sources
PubMed1997

Trypanosoma brucei: identification of an internal region of phosphoglycerate kinase required for targeting to glycosomal microbodies.

Among the microbodies found in eukaryotes are the glycosomes of Trypanosoma brucei, thought to be closely related to peroxisomes. Two types of targeting signals for glycosomes have been identified thus far: type 1 at the C-terminus and type 2 at the N-terminus. In this report, we use an epitope-tagging system to characterize the targeting signal found on the minor glycosomal isozyme of phosphoglycerate kinase, 56PGK. No type 1 or 2 signal was found; rather, the topogenic information was found to be internal. Chimeric molecules formed with the cytoplasmic phosphoglycerate kinase isozyme indicate that a region between amino acids 24 and 91 of 56PGK is essential for glycosomal targeting. No homology was found between this region and peroxisomal proteins containing internal targeting signals.

Amino Acid Sequence↗
PubMed1997

[Soft tissue sarcoma of the head and neck area in adults. Outcome of combined surgery and irradiation and radiotherapy alone].

PURPOSE: To analyse the experience treating soft tissue sarcomas of the head and neck at the Massachusetts General Hospital, Boston. Detailed results have been published previously [17]. PATIENTS AND METHOD: Between 1972 and 1993, 57 patients were treated curatively with radiation alone (n = 13) or combined surgery and pre- and/or postoperative irradiation (n = 44). Gross complete resection was achieved in 82% of patients and margins were negative in 5 patients. Doses ranged from 36.0 to 79.2 Gy (median 64.8 Gy), usually conventionally fractionated. In 16 patients protons were used. Median follow-up time was 4.3 years (range 1.1 to 16.8 years). RESULTS: After 5 years, patients with angiosarcomas (n = 11) and patients with other tumor types (n = 46) had locoregional control rates of 24% and 69%, distant failure rates of 58% and 17%, and overall survival rates of (for overall survival) and T stage (for locoregional control) (p < 0.05). Particularly, gross completely resected T1 tumors had a locoregional control rate of 91%. Patients with locoregional recurrence were at an increased risk to die (p = 0.004 in multivariate analysis). Patients with and without direct tumor extension to neurovascular structures, bones, organs, or skin had distant failure rates of 27% and 0%, respectively (p = 0.031). In multivariate analysis, direct extension was additionally a negative prognosticator of overall survival (p = 0.034). CONCLUSION: 1. Angiosarcomas of the head and neck have a considerably poorer prognosis than other soft tissue sarcomas of this region. 2. Head and neck sarcomas have a higher local recurrence rate than for example soft tissue sarcomas of the extremities. Optimisation of local treatment through combination of surgery and high-dose irradiation, however, can achieve improved results, especially for prognostically favourable subgroups. 3. In addition to tumor grade and size, direct tumor extension may be a useful additional staging parameter.

Adult↗
PubMed1997

Angiographic study of moyamoya disease and histological study in the external carotid artery system.

A total of 13 cases of Moyamoya disease were verified by internal and external carotid artery angiography. The biopsy samples were taken from the superficial temporal arteries and middle meningeal arteries in 12 and six cases, respectively. Angiographical and histological studies revealed that both of the internal and external carotid system could be involved in Moyamoya disease. Our studies demonstrated that Moyamoya disease was a type of vascular disease not only confined to the cerebral vessels. We recommend angiography of external carotid system and extracranial segment of internal carotid artery while performing three vascular angiography. Whether superficial temporal artery has been involved in angiography can be used as an indication of indirect cerebrovascular bypass.

Biopsy↗
PubMed1997

Successful radiofrequency ablation of idiopathic left ventricular tachycardia at a site away from the tachycardia exit.

OBJECTIVES: This study sought to assess the possibility of ablating verapamil-responsive idiopathic left ventricular tachycardia at a site distant from the tachycardia exit and thus to define the tachycardia circuit. BACKGROUND: The nature of the reentry circuit in idiopathic left ventricular tachycardia is unclear. If the circuit is of considerable size, then it should be possible to ablate the tachycardia at a site distant from the exit site. METHODS: Electrophysiologic studies and radiofrequency ablation were performed in 27 consecutive patients with verapamil-responsive idiopathic left ventricular tachycardia. In all 27 patients, the tachycardia exit site was defined as the site where the earliest Purkinje potential was recorded > or = 25 ms before the onset of the QRS complex during the tachycardia and where the pace map QRS complex resembled that during the tachycardia. A potential ablation site other than the exit site was then sought around the midseptum, proximal to the exit site. At such sites the tachycardia could be terminated transiently by pressure applied to the catheter tip, without induction of ventricular ectopic beats. RESULTS: The potential ablation site, other than the tachycardia exit site, was identified in seven male patients (mean [+/-SD] age 31 +/- 12 years, range 13 to 52). Application of the radiofrequency current at this site resulted in termination of the tachycardia within 1 to 5 s (mean 2.9 +/- 1.6), and successful ablation of the tachycardia was achieved in all seven patients (success rate 100%, 95% exact confidence interval 0.5898 to 1). The mean distance between the ablation site and the tachycardia exit site was 3.1 +/- 0.7 cm (range 2.0 to 4.0). A presystolic Purkinje spike was recorded 14 +/- 5 ms (range 8 to 20) before the onset of the QRS complex during the tachycardia. During the follow-up period of 24 +/- 11 months (range 12 to 39), there was no recurrence of tachycardia in these seven patients. CONCLUSIONS: Successful ablation of idiopathic left ventricular tachycardia can be achieved at sites away from the tachycardia exit site in some patients. This finding suggests that the reentry circuit is likely to be of considerable size, encompassing the middle, inferior and lower aspects of the left interventricular septum.

Action Potentials↗
PubMed1997

Ribotyping and random amplification of polymorphic DNA for nosocomial Enterobacter cloacae isolates in a pediatric intensive-care unit.

Between 1987 and 1989, two sequential outbreaks of nosocomial infection caused by Enterobacter cloacae occur-red in the pediatric intensive-care unit of a tertiary-care teaching hospital. Seventeen strains retrieved from the outbreaks and two control strains identified in other wards were typed by ribotyping and random amplification of polymorphic DNA (RAPD). The results indicated that the genomic pattern of strains identified between the first and second outbreaks was different. We conclude that both ribotyping and RAPD are highly discriminatory and reproducible methods for typing E cloacae. RAPD seems to be more efficacious and cost-effective.

Bacterial Typing Techniques↗
PubMed1997

Isolated common iliac artery occlusion secondary to atherosclerotic plaque rupture from blunt abdominal trauma: case report and review of the literature.

Traumatic isolated common iliac artery occlusion is unusual. Only rare cases of common iliac arterial injuries resulting from blunt abdominal trauma have been reported, and most of them were attributed to the seat-belt syndrome and associated with visceral organ perforation or pelvic fracture. We reported an unusual isolated common iliac artery occlusion secondary to atherosclerotic plaque rupture from blunt abdominal compressive trauma without other visceral injury. This case presented with acute limb ischemia and paralysis that was successfully treated by thromboendarterectomy. The symptoms and signs, surgical modalities, and associated injuries were reported and the literature was also reviewed.

Arterial Occlusive Diseases↗
PubMed1997

Lipid peroxidation in cord blood: the effect of amniotic fluid volume.

OBJECTIVE: To assess the effect of amniotic fluid volume on umbilical cord arterial lipid peroxide levels in relation to intrapartum events. DESIGN: Prospective observational study. SETTING: Delivery suite of a teaching hospital, the Chinese University of Hong Kong. POPULATION: Women with singleton, term, cephalic presentation, and an initially normal fetal heart rate tracing. METHODS: All pregnancies had amniotic fluid index assessments before and after amniotomy and cord arterial lipid peroxide determination at delivery. Multiple regression analysis. MAIN OUTCOME MEASURES: Cord arterial malondialdehyde and organic hydroperoxide levels. RESULTS: In 247 cases following amniotomy levels were inversely correlated with intrapartum amniotic fluid index. Amniotic fluid index during labour was an independent determinant of cord arterial lipid peroxide concentration, along with duration of second stage, absence of epidural, presence of tight nuchal cord entanglement and evidence of fetal distress. CONCLUSIONS: Oligohydramnios during labour is associated with high levels of lipid peroxidation in the fetus, reflecting an increase in hypoxic cellular damage by free radicals.

Amnion↗
PubMed1997

Lipid peroxidation in cord blood: a randomised sequential pairs study of prophylactic saline amnioinfusion for intrapartum oligohydramnios.

OBJECTIVE: To determine the efficacy of prophylactic intrapartum amnioinfusion in reducing cord arterial lipid peroxide levels in cases of intrapartum oligohydramnios. DESIGN: Sequential randomised pairs trial. SETTING: Delivery suite of a teaching hospital, the Chinese University of Hong Kong. POPULATION: Women with singleton, term pregnancy, cephalic presentation, clear amniotic fluid and an amniotic fluid index < or = 5 cm, with a normal intrapartum fetal heart rate tracing within 30 minutes of amniotomy. METHODS: Selected patients were randomised either for prophylactic saline amnioinfusion or as control cases. Cord arterial lipid peroxide concentrations and acid base balance were determined at delivery. MAIN OUTCOME MEASURES: Operative intervention for fetal distress, cord arterial malondialdehyde and organic hydroperoxide levels, pH and base excess. RESULTS: Amnioinfusion was associated with significant reductions in the incidence of operative delivery for fetal distress and in lipid peroxide levels, an increase in base excess, but no significant alteration in pH. CONCLUSIONS: Oligohydramnios in labour is associated with high levels of lipid peroxidation, reflecting cellular damage by release of free radicals following hypoxia reperfusion. Prophylactic intrapartum saline amnioinfusion is an effective technique for the reduction of lipid peroxidation and of the incidence of operative intervention for fetal distress but has no significant effect on overall operative delivery rates.

Amniotic Fluid↗
PubMed1997

Lipid peroxidation in cord blood: the effects of umbilical nuchal cord.

OBJECTIVE: To examine the relation between cord entanglement around the fetal neck and umbilical arterial measures of free oxygen radical activity at birth. DESIGN: Prospective observational study of the lipid peroxide levels in umbilical cord arterial blood. SETTING: Delivery suite of Prince of Wales Hospital, Hong Kong. POPULATION: Women with a singleton pregnancy, at term (37 to 42 weeks of gestation), cephalic presentation, spontaneous or induced labour and an initially normal fetal heart rate tracing. METHODS: A series of 230 singleton deliveries had determination of two lipoperoxides in umbilical arterial cord blood: malondialdehyde and organic hydroperoxide. Umbilical pH, PO2, PCO2 and base excess were also measured in both umbilical cord arterial and venous blood. MAIN OUTCOME MEASURES: Umbilical cord blood gases and arterial malondialdehyde and organic hydroperoxide levels. RESULTS: Forty-nine cases of nuchal cord were observed: 14 tight and 35 loose. Tight nuchal cord was associated with a low 1-min Apgar score and increased lipid peroxide levels. Loose nuchal cord was associated with larger amniotic fluid volume and significantly decreased lipid peroxide levels. CONCLUSIONS: This study suggests that tight nuchal cord is associated with increased free oxygen radical activity in the fetus, but that loose nuchal cord carries no adverse effects.

Female↗
PubMed1997

Atypical atrioventricular nodal reentry tachycardia with atrioventricular block mimicking atrial tachycardia: electrophysiologic properties and radiofrequency ablation therapy.

INTRODUCTION: Fast-intermediate form AV nodal reentry tachycardia (AVNRT) sometimes may mimic atrial tachycardia or atrial flutter and render the diagnosis difficult when the tachycardia rate is fast and AV block occurs during tachycardia. METHODS AND RESULTS: A 45-year-old woman with paroxysmal supraventricular tachycardia was referred to this institution. Initially, the tachycardia was thought to be an atrial tachycardia because of: (1) a short cycle length of the tachycardia with 2:1 and Wenckebach AV block; (2) a difference in the atrial activation sequence during tachycardia and during ventricular pacing; and (3) failure of burst ventricular pacing to affect the atrial rate and the atrial activation sequence during tachycardia. An accurate diagnosis of fast-intermediate form AVNRT was subsequently made based on the finding that the tachycardia was induced following delivery of a third ventricular extrastimulus, which showed a sequence of V-A-H and a change on atrial activation sequence of the induced beat. Successful radiofrequency ablation was achieved only after accurate diagnosis of the tachycardia was made. CONCLUSION: Fast-intermediate form AVNRT sometimes may masquerade as atrial tachycardia. Accurate diagnosis is mandatory for successful ablation therapy.

Catheter Ablation↗
PubMed1997

Human babesiosis in Taiwan: asymptomatic infection with a Babesia microti-like organism in a Taiwanese woman.

An asymptomatic Babesia infection was confirmed by laboratory diagnoses. The intraerythrocytic protozoan (designed TW1) isolated from a 51-year-old Taiwanese woman appeared to be morphologically consistent with small-form piroplasm, and measurements indicated that it had a body size of 1.5 to 2.5 microm in diameter. The typical features of ring, binary, and tetrad forms were observed in Giemsa-stained thin blood smears. A persistent and low-grade parasitemia was established after hamster inoculation. Indirect immunofluorescent-antibody reactivities indicate that this strain (TW1) of Babesia was serologically related to, but not identical to, the Babesia species (B. microti) that infects rodents. Antibody titers in the patient's sera combined with the clinical symptoms suggested that the present case was a chronic and subclinical babesial infection. A neighborhood human serologic survey indicated that the infection may have been acquired accidentally from an infected rodent and localized within the same family. Indeed, rodents from areas around the neighborhood were trapped, and a high prevalence (83%) of babesial infection was observed. The possible vector responsible for the transmission remains to be identified.

Animals↗
PubMed1997

Oxygen free radical activity in the second stage of labor.

OBJECTIVE: To assess fetal cellular injury arising from oxygen free radical activity in relation to the duration of the second stage of labor. PATIENTS AND METHODS: Cord arterial pH, malondialdehyde and organic hydroperoxides levels were determined following vaginal delivery of 326 term singleton pregnancies. Of these, 35 (11%) received epidural analgesia. The length of the second stage was recorded from the time of full dilatation to delivery. RESULTS: Arterial cord pH, malondialdehyde and organic hydroperoxides were significantly correlated with duration of second stage of labor (r=-0.4492; r=0.2542; r=0.2244; respectively, p<0.001). The association of lipid peroxidation products with second stage duration was independent of cord pH. This correlation was unchanged when cases of operative delivery were excluded. However, the relationship lost statistical significance amongst cases who received epidurals. CONCLUSIONS: The duration of the second stage is correlated with raised reactive oxygen species-derived lipid peroxidation products. Caution should be exercised in the management of prolonged second stage of labor.

Adolescent↗
PubMed1997

[Antigen strategy: a new way for gene therapy].

Synthetic purine-rich or pyridine-rich oligonucleotides have been shown to form stable triplex by binding to specific homopurine-homopyridine sequences in double-stranded DNA. Several studies have suggested that triplex formation in the transcription-regulated regions of genes could inhibit their transcription in vitro or in vivo. This new technology was called antigene strategy, which would be of great value in the treatment of cancer and virus infection. However, the low stability of triplex and restricting target selection of homopurine-homopyridine tracts in selected genes greatly reduced its utility in antigen strategies. Further work is still needed.

DNA↗
PubMed1997

Development and validation of a particle-enhanced turbidimetric inhibition assay for urine albumin on the Dade aca analyzer.

The measurement of urine albumin now has a well-established role in the monitoring of patients with diabetes mellitus. We have developed a particle-enhanced immunoturbidimetric inhibition assay for urine albumin on the Dade aca analyzer. The inhibition approach removes any of the potential antigen excess difficulties that could be expected from the wide clinical range of urine albumin, but retains the sensitivity advantages of latex-enhanced immunoturbidimetry. Human serum albumin (HSA) is covalently attached to 40-nm poly(chloromethyl)styrene-modified latex particles. This reagent, along with monoclonal antibody to HSA, is aliquoted into the aca reagent pack along with polyethylene glycol 8000 in a tablet form (giving a final reaction concentration of 15 g/L). A 150 mmol/L phosphate buffer, pH 7.8, is used to fill the reagent pack in the instrument and the agglutination reaction is monitored at 340 nm. The sample volume is 100 microL and the calibration curve covers the range 2-250 mg/L. Evaluation of commercial scale reagents against the Beckman Array nephelometric immunoassay system gave a Deming regression correlation of aca = 0.87 x Beckman + 8.5, r = 0.995, n = 145. Mean analytical recovery was 104+/-4.5%, n = 20, and there was no evidence of a lack of parallelism. Interassay precision was 8.8% at 10.0 mg/L and <2.5% at >65 mg/L. Calibrator stability was in excess of 60 days. A small reference range study (24-h urine collections, n = 27) gave a mean of 5.6 mg/L with a range of 0.5-16.2 mg/L. Analytical sensitivity (2.5 SD from zero) was 0.40 mg/L.

Albuminuria↗
PubMed1997

Periodontal manifestations and treatment of Sturge-Weber syndrome--report of two cases.

Encephalotrigeminal angiomatosis (Sturge-Weber syndrome) is a rather uncommon congenital condition characterized by the combination of venous angioma of the leptomeninges over the cerebral cortex with ipsilateral angiomatous lesions of the face and sometimes, the skull, jaws and oral soft tissues. Two patients came to the Kaohsiung Medical College Hospital's dental clinic with complaints of localized gingival enlargement or tumor-like swelling. Based on the presence of facial nevus flammeus, examinations of angiography, radiological evidence of calcific densities, and ipsilaterally intraoral vascular hyperplasia in the lip, cheek and gingiva, encephalotrigeminal angiomatosis was diagnosed. Dental management included plaque control instructions, scaling, root planing and periodontal surgery. Recurrence of gingival enlargement in both cases was noted, so periodontal surgery was performed a second time. Close follow up and complete plaque control have kept the periodontal condition fairly well under control in these two cases. We introduce the oral manifestations and the experience of treatments in these two cases.

Adolescent↗