Biomedical subjects

K C Wang

Publications and source records attributed to K C Wang.

At least 73 records · Page 4Linked to original sources

PubMed1998

Brain tumor in the first year of life: a single institute study.

Brain tumors in infants present special diagnostic and therapeutic challenges. To figure out the clinical features, pathological classification of the tumors and the treatment outcome of infantile brain tumors, 458 children (age<16) with brain tumors were reviewed retrospectively. Among them 21 cases (4.6%) were diagnosed during the first 12 months of life. Two tumors were definitely of congenital origin. The majority of infants with brain tumors presented with increased intracranial pressure. Fourteen tumors were located at the supratentorial area. Sixteen cases had neuroepithelial tumors; astrocytoma (optic pathway), supratentorial primitive neuroectodermal tumor (PNET) and medulloblastoma were found in three cases each. There were two treatment-related mortalities. Compared with the outcomes in older children, the treatment outcome was poorer in medulloblastoma and the optic pathway glioma which showed a higher growth potential. Because of the limited application of postoperative adjuvant therapy, radical surgical removal played a more important role in this age group. The prognosis of patients in whom the tumors could not be totally removed, largely depended on the pathological malignancy of the tumors. Though the treatment outcome was not always dismal, immaturity of the brain, higher growth potential, perioperative risks, limitations in adjuvant therapy, and pessimistic attitude on the part of parents made management more challenging.

Adolescent↗

PubMed1998

Cytokinetic pattern in the thoracic spinal cord of chick embryos (incubation day 5-13) using PCNA staining and TUNEL method.

For the cytokinetic studies using spinal cords of chick embryos, chronological patterns of cell proliferation and programmed cell death (apoptosis) should be known. Information in the early stages of chick embryos is available while data on later stages are seldom available. To investigate the chronological patterns of cell proliferation and apoptosis in the thoracic spinal cord of normal chick embryos on incubation day 5, 6, 8, 10 and 13 (Hamburger and Hamilton stage 26-40), proliferating cell nuclear antigen (PCNA) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method were used. Cell proliferation was active at the germinal layer on days 5 and 6. It markedly declined on day 8 and became negligible on day 13. TUNEL-positive cells were mainly found in the germinal layer, the ventrolateral part of the mantle layer and the dorsal root ganglion. Compared to PCNA-positive cells, TUNEL-positive cells were sparse, especially after day 10, when only a few positive cells were scattered. These results will be used as a control data for the studies such as an experimental research for neural tube defects.

Animals↗

PubMed1998

[An epidemiological study of the adolescent nonfatal unintentional injuries in Taiwan].

In Taiwan, the unintentional injury is the major cause of morbidity, mortality, and school absenteeism among adolescents. This problem has been ignored in past years, so this investigation was undertaken to alert public, school, and parental attention and concern, to establish the baseline data for adolescent unintentional injuries, and to provide information and guidance for adolescent injury prevention and control programs. Two thousand-three hundred and seventeen students were randomly sampled from 1,115 junior high, senior high, and vocational schools in Taiwan during the 1994-1995 academic year through a multi-stage stratified cluster random sampling with probabilities proportional to sizes. The data were collected via the self-reported adolescent unintentional injury records, and analyzed with frequency distribution, Pearson's Chi-square statistics, and product-moment correlation coefficient. It was found that an overall injury rate (per season) was 56.37% (1292/2292). The rates were higher for boys than girls, for junior high students than senior high or vocational students, for those being near-sighted, for those having a history of previous injuries, and for younger students. Abrasions, sprains, bumps, cuts, and falls were the five most common injuries among adolescents, and mostly appeared in upper and lower extremities. Most injuries took place in athletic fields, classrooms, campus, stairways and corridors at school, mainly due to self, others of carelessness, and sports.

Adolescent↗

PubMed1998

High-grade endometrial stromal sarcoma in a 10-year-old girl: case report.

Endometrial stromal sarcomas occur primarily in perimenopausal women and are quite uncommon in children. We report a case of high-grade endometrial stromal sarcoma in a 10-year-old girl, who initially experienced lower abdominal pain on voiding. After a series of examinations, surgical treatment was performed, including an extended total hysterectomy with bilateral salpingo-oophorectomy, bilateral pelvic lymph node sampling, and partial omentectomy. Adjuvant radiotherapy and hormonal therapy followed, however, the abdominal tumor recurred 9 months later. Invasion of the right lobe of the liver with compression of the inferior vena cava and pleural effusion was noted. The patient then received prolonged oral etoposide therapy. The treatment stabilized the tumor size and relieved her symptoms for 4 months. She finally succumbed to the disease as a result of distant metastasis.

Child↗

PubMed1997

Functional significance of the TATA element major groove in transcription initiation by RNA polymerase II.

The binding of TFIID to the TATA element initiates assembly of a preinitiation complex and thus represents one of the most important steps for transcriptional regulation. The fact that the TATA binding protein (TBP), a subunit of TFIID, exclusively contacts the minor groove of the TATA element led us to ask whether the major groove of the TATA element plays any role in transcription initiation or its regulation. Our results show that modifications of the major groove of the TATA element in the adenovirus major late promoter have no effect on TFIID binding affinity or on transcription in a cell-free system reconstituted with purified factors. However, major groove modifications do decrease the levels of both basal and activator-mediated transcription in unfractionated nuclear extracts, indicating that the intact structure of the major groove of the TATA element is functionally important for transcription initiation in a more physiological context.

Adenoviridae↗

PubMed1997

Bobble-head doll syndrome associated with subduroperitoneal shunt malfunction.

Bobble-head doll syndrome is known to be associated with aqueductal stenosis or cystic lesions of the III ventricle. The direction of movement is usually vertical. In the literature, only five cases of purely horizontal movement have been reported. Bobble-head doll syndrome manifested as a sign of shunt malfunction has been described in one case with a ventriculoperitoneal shunt. The authors report on a 10-year-old boy who showed subduroperitoneal shunt malfunction associated with horizontal bobble-head doll syndrome. The head bobbing disappeared immediately after shunt revision. Unlike the previously reported cases, in the present case the lesion was asymmetric, though the significance of this for the lateral movement is not clear. This case also showed more marked ventricular dilatation on subduroperitoneal shunt malfunction than in the pre-shunt state. The underlying mechanism of the ventricular dilatation is unknown.

Child↗

PubMed1997

Renovascular hypertension in children with moyamoya disease.

OBJECTIVES: To examine the incidence, clinical and radiologic findings, and response to treatment of renovascular hypertension (RVHT) in moyamoya disease (MMD). METHODS: A retrospective analysis of medical records in six RVHT cases (8.3%) among 72 MMD patients observed from November 1987 to December 1995. RESULTS: The age at onset of MMD ranged from 9 months to 7 years 1 month (mean, 3.3 years). The most common initial manifestation of MMD was transient ischemic attack. Hypertension was detected between 4 years 4 months and 12 years 3 months (mean, 7.87 years). Unstimulated plasma renin activity was elevated in all six cases. Renal ultrasonography and captopril technetium 99m-labeled dimercaptosuccinic acid scan showed abnormal findings in four of five and in three of four available studies, respectively. However, both imaging studies showed abnormal findings only in the most severely affected kidneys even with bilateral renal artery stenosis. Renal arteriography revealed bilateral lesions in three of the patients and unilateral lesions in the others. Renal angioplasty was performed in four cases but was successful in only one and partially successful in another. A renal artery specimen obtained during renal autotransplantation showed intimal fibroplasia. At the last follow-up, one patient had normal blood pressure without the use of antihypertensive agents, but the other five patients needed this medication to control blood pressure. CONCLUSION: Because RVHT may be more commonly associated with MMD than has hitherto been appreciated, it is recommended that blood pressure be carefully followed and that diagnostic procedures for RVHT be carried out in hypertensive patients with MMD.

Adolescent↗

PubMed1997

Reverse pedicled lateral arm flap for reconstruction of posterior soft-tissue defects of the elbow.

Posterior soft-tissue defects of the elbow are difficult to reconstruct by conventional techniques such as closure by approximation or skin graft. An ideal technique should be an easy and reliable one-stage procedure that provides predictable surgical results with regard to elbow function and cosmesis. This report details our experience in 7 patients who underwent a one-stage procedure for coverage of the posterior elbow employing the reverse pedicled lateral arm flap. All flaps survived and all patients were able to resume full range of motion of the elbow joint at the 6-month follow-up. Complications included forearm paraesthesia in 3 patients and conspicuous scarring in a young female patient. We emphasize two valuable refinements in surgical technique including measuring posterior elbow defect in full flexion and postoperative elbow extension splinting. In trauma-related defects of the posterior elbow, a preoperative angiogram is important before raising this flap.

Adolescent↗

PubMed1997

Complications of pediatric craniofacial surgery in the Orient: analysis of a 10-year experience.

Numerous reports on the complications of craniofacial surgery have been published in the western world. However, relatively little such information concerning Oriental populations has been documented. We therefore set out to provide a retrospective analysis of all the complications of craniofacial surgery encountered during the 10-year period of 1986 to 1995 at Seoul National University Children's Hospital, the only children's hospital in Korea. Forty-nine children underwent 57 consecutive craniofacial procedures at our institution during 1986 to 1995. A retrospective chart analysis of the frequency and types of complications was performed. Mantel-Haenszel chi-square tests were then calculated for several factors, including age at surgery, duration of surgery, intraoperative losses of hemoglobin and hematocrit, total amount of blood transfusion, and the number of complications according to year, diagnosis, and operative procedure to find any significant correlation with the incidence of complications. Mortality was 1.8%. The major complication rate was 7.0% and included cases of visual loss and persistent cerebrospinal fluid leak. Analysis revealed the presence of several trends, including an increased incidence of complications with increased patient age at surgery, duration of surgery, and intraoperative loss of hematocrit. The number of complications was also noted to increase in cases with complex craniofacial synostosis syndromes (Crouzon's, Apert's Antley-Bixler, etc.) and tumors of the orbit and cranium. Finally, complications were noted to decrease in recent years, most likely due to the increased experience of our craniofacial team. Nevertheless, statistical analysis revealed that the incidence of complications correlated significantly only with increased duration of surgery (p < 0.05). The results of our study indicate that although craniofacial surgery in the Orient carries an inherent risk for significant complications, the risk can be minimized and the rate of mortality and major complications kept to an acceptable level by a careful and experienced craniofacial team. Groups at most risk for complications are those with a long duration of surgery.

Adolescent↗

PubMed1997

Cerebral sparganosis in a child.

Cerebral sparganosis in childhood is very rare. Until 1996, 2 cases in children up to 15 years of age had been described. We report a case of cerebral sparganosis in a 6-year-old girl who presented with seizures. Sequential brain magnetic resonance imaging scans spaced over 4 months showed a lesion which migrated from the right parieto-occipital region to the right occipital region. The enzyme-linked immunosorbent assay for antisparganum antibody was positive. She most likely contracted sparganosis from worm-infested spring-water. A live worm with surrounding granulomatous tissue was removed, and the enzyme-linked immunosorbent assay for antisparganum antibody converted to negative 12 months following surgery. In areas of endemic sparganosis, the possibility of cerebral sparganosis should be considered, even in a child, if the patient shows a migrating granulomatous lesion.

Brain Diseases↗

PubMed1997

Functional opening of the fourth ventricular outlet in C57BL/6J and delayed splotch mouse embryos.

To compare the functional development of the fourth ventricular outlet in the myeloschisis-Chiari malformation complex with that of a normal brain, the chronological development of the outlet in C57BL/6J non-neural-tube defect mouse embryos was examined as the first step. Then we compared the results with those of homozygotic delayed splotch (Spd) mouse embryos which had neural-tube defects (NTDs). Ferrous chloride (Prussian blue) solution was injected into the lateral or mesencephalic ventricle on gestation days 13-16 in the case of control C57BL/6J mouse embryos and on gestation days 14-16 in the case of homozygotic Spd mouse embryos which had open spinal NTDs and hindbrain anomalies comparable to human Chiari malformation. At 30 min after the injection, acid fixative was infused through the heart to set off the Prussian blue reaction, which makes the dye visible by the precipitation of ferric chloride. According to the present method, more than 75% of C57BL/6J mouse (non-NTD control) embryos showed the evidence of function of the fourth ventricular (4V) outlet from gestation day 15. It was difficult to apply the same method to Spd mouse embryos with NTDs due to the small size of ventricles. Only 4 injections were successful, of which 3 showed the functioning evidence of the 4V outlet. Though the number of mouse embryos with NTDs studied was small, the results suggest that the chronological progress of functional opening of the fourth ventricle in mouse embryos with NTDs is similar to that of control non-NTD embryos.

Animals↗

PubMed1997

Choroid plexus carcinoma in an infant.

Choroid plexus carcinoma is a rare tumor and has a strong tendency to spread along the cerebrospinal fluid pathway. The tumor frequently occurs in infants. Radiation therapy is not indicated in infants and the response of this tumor to chemotherapy is variable. Therefore, surgical removal plays a major role in the management of this tumor, especially in infants. A 2-month-old girl with an acute communicating hydrocephalus was presented. Through the left posterior parietal transcortical approach, a choroid plexus carcinoma which had poor demarcation from the posterior thalamus and the medial wall of the lateral ventricle was subtotally (> 95%) removed. Postoperatively a ventriculoperitoneal shunt was inserted. Chemotherapy was refused. Magnetic resonance imaging taken at 11 months after surgery showed multiple intracranial seeding of the tumor. She was in a bed-ridden state. This case revealed the aggressive behaviour of choroid plexus carcinoma in an infant and the dismal result of subtotal removal alone, though it is rather radical.

Choroid Plexus Neoplasms↗

PubMed1997

Cerebral leiomyoma in a child.

A case of primary cerebral leiomyoma in a 12 year-old boy with unique clinical features is described. He presented with fever, and the magnetic resonance imaging demonstrated a well demarcated mass in the subcortical white matter of the right temporal lobe. The mass showed low signal intensity on T1-weighted images and high signal intensity on T2-weighted images with a strong homogeneous gadolinium-DTPA enhancement. The mass was removed in toto and was composed of fasciculating, monotonous oval to spindle cells which had both immunohistochemical and ultrastructural features of primitive smooth muscle differentiation. The patient is free of recurrence during the follow-up period of 56 months. Detailed clinicopathologic findings are discussed.

Brain Neoplasms↗

PubMed1997

Pyomyositis of the calf muscles mimicking distal deep venous thrombosis: a case report.

Pyomyositis is a pyogenic infection of skeletal muscle. It is relatively rare in temperate climates. Unfamiliarity with the lesion may lead to a delay in diagnosis. This report describes pyomyositis of the calf muscles in a patient with chronic hepatitis whose clinical symptoms simulated those of distal deep venous thrombosis. The correct diagnosis was not made until computed tomography revealed a local abscess in the calf muscles.

Abscess↗

PubMed1997

Metabolic characteristics and enflurane defluorination of cytochrome P450-dependent monooxygenases in human hepatocellular carcinoma.

BACKGROUND: Xenobiotic metabolism and defluorination capacity of microsomal monooxygenases were investigated in vitro through the surgical specimens of liver resected from patients with hepatocellular carcinoma and patients of extrahepatic pathology as control. METHODS: In microsomes of hepatocellular carcinoma tissues, the activities of cytochrome P450-dependent monooxygenase isoenzymes 1A1, 2B1, and 2E1 were evaluated in vitro by reacting with the specific marker substrates benzo(a)pyrene, benzphetamine and aniline, respectively, in the generating incubation system. The distant normal liver tissues and tissues from control patients with extrahepatic lesion were also investigated for comparison. The ability of enflurane defluorination was assessed by Orion combined for detection of free fluoride ion production. RESULTS: Concentrations of P450 total content, cytochrome b5, and NADPH-cytochrome c reductase showed parallel and marked reduction in tumor tissues when compared with its distant normal regions or normal livers. The monooxygenase functions displayed significant decreases within the tumor tissues as benzo(a)pyrene hydroxylation > or = benzphetamine demethylation > aniline hydroxylation in magnitude. Defluorination of enflurane also markedly decreased in tumor tissues comparing with normal livers. CONCLUSIONS: These marked reductions in the compositions and in vitro metabolic activities, including defluorination of anesthetics, in the cytochrome P450-dependent monooxygenases within the tumor tissues characterize the unique pattern of xenobiotic metabolism in patients with hepatocellular carcinoma.

Aged↗

PubMed1997

Slipped capital femoral epiphyses in a patient with primary hyperparathyroidism.

Slipped capital femoral epiphyses are rarely associated with primary hyperparathyroidism, and only four cases have been documented in the English literature. We report such a case. A 13-year-old boy presented with bilateral slipped capital femoral epiphyses. Investigation showed that he had primary hyperparathyroidism due to a parathyroid adenoma. The adenoma was removed, and then the epiphyses were pinned in situ 3 weeks later. The pins were removed 3 months postoperatively when the physes had closed. The patient had a painless hip 1 year later at follow-up. We concluded that identification and excision of the hyperparathyroid adenoma and in situ pinning of the slipped epiphyses results in satisfactory treatment of the condition.

Adenoma↗

PubMed1996

Promotion of synthetic amyloid beta-peptide fibrillization by cell culture media and cessation of fibrillization by serum.

Dulbecco's modified Eagle's medium promotes aggregation and fibrillization of the synthetic amyloid beta 1-40 and beta 1-42 peptides more than RPMI and OPTI media. Fibrillization in all of these media is faster than in phosphate-buffered saline and Tris buffer. Normal and heat-inactivated fetal bovine and human serum abolish amyloid fibril formation in buffers and cell culture media. Fibrillar amyloid formed during 2-day-long incubation in cell culture media and buffers is defibrillized by 1-day-long treatment with human and bovine serum. This study indicates that amyloid beta fibrillogenesis in cell culture should be studied in serum-free media or in media with a low concentration of serum.

Amyloid beta-Protein Precursor↗

PubMed1996

Comparison of skeletal muscle microcirculation between clamp ischemia and microsurgical ischemia.

We compared ischemia reperfusion injury-associated vasospasm and perfused capillary density (PCD) at the microcirculatory level between clamp ischemia and microsurgical ischemia in rat skeletal muscle. Rat cremaster muscle was prepared as an island flap, attached only with pudic-epigastric vessels branching from external iliac vessels. Two types of ischemia, with clamping only or with microvascular anastomosis, were applied at the external iliac vessels for 2 hours followed by 1-hour reperfusion before in vivo microscopic examination for hemodynamic changes. At the end of observation, small segments of the vessels at the clamping site and microsurgical anastomoses site were also harvested for histological examination. It was found that the first- and second-order arterioles had about 12-15% diameter reductions in both groups, whereas diameter reductions of the third-order arterioles were up to 37.8% in the microsurgical ischemia group, much greater than that in the clamp ischemia group (2.3%). There was also no significant difference in PCD reduction between the two groups, although the red blood cell velocity was much slower in the microsurgical ischemia group. Histological examination of the anastomosis site showed massive accumulation of polymorphonuclear neutrophils on the venous endothelium. These results suggested a different degree of endothelial damage and local leukocyte activation between microsurgical ischemia and clamp ischemia. Therefore, we conclude that clamp ischemia cannot replace microsurgical ischemia for studying microcirculatory changes in free tissue transfer.

Anastomosis, Surgical↗