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Biomedical subjects

K C Wang

Publications and source records attributed to K C Wang.

At least 91 records · Page 5Linked to original sources
PubMed1996

Primary intramedullary spinal cord primitive neuroectodermal tumor with intracranial seeding in an infant.

Primary spinal cord primitive neuroectodermal tumor (PNET) is a rare entity. In all 13 cases have been reported in the literature, including 3 with intracranial seeding. A 3-month-old girl with involvement of the spinal cord below the mid-thoracic level is described. The brain MRI revealed findings indicative of seeding along the intracranial subarachnoid space. Biopsy, duraplasty and removal of laminotomy flap were done. In spite of a good response to the first cycle of postoperative "8-drugs-in-a-day' chemotherapy, further treatment was refused. She died 21 days after the onset of leg weakness, which reveals the rapid progression of untreated cases. To our knowledge, this is the first case of spinal cord PNET with parenchymal involvement that has been described in an infant.

Fatal Outcome↗
PubMed1996

Concanavalin-A-induced open neural tube defects in chick embryos.

Open neural tube defects developed in 12 of 122 alive chick embryos treated with exogenous lectin (concanavalin-A) at stages between 10 or 14 as defined by Hamburger and Hamilton. Embryos treated at stage 10, the time of anterior neuropore closure, developed exencephaly or extensive neural openings from the level of rhombencephalon to the thoracic spinal cord, while embryos treated at stages between 11 and 14, at posterior neuropore closure, developed only small myeloschisis in the thoracolumbar region. The failure of neural tube closure at a critical time is a major cause of neural tube defects.

Animals↗
PubMed1996

Cerebral sparganosis: clinical manifestations, treatment, and outcome.

Cerebral sparganosis is a rare parasitic disease caused by infestation by the plerocercoid larva of Spirometra mansoni. The authors retrospectively analyzed 17 cases of cerebral sparganosis treated at Seoul National University Hospital between 1986 and 1994. The patients' ages at diagnosis ranged from 6 to 57 years (median 32 years) and the male/female ratio was 13:4. Diagnosis was based on radiological findings, serological test results, operative findings, and histopathological examinations. Characteristic magnetic resonance (MR) findings consisted of widespread white matter degeneration and cortical atrophy, mixed-signal lesion (low in the central and high in the peripheral regions on T2-weighted images) with irregular dense enhancement of central foci and changes in the location and shape of the enhancing lesion in follow-up studies. Ten patients underwent surgical removal of the parasitic lesion, six received medical treatment alone (five with praziquantel and one with antiepileptic drugs), and one underwent insertion of a ventriculoperitoneal shunt and a course of praziquantel. Follow-up periods ranged from 13 to 111 months (mean 49 months). Seven patients who underwent complete removal of the lesion, live worm, or degenerative worm with surrounding granuloma showed a favorable course. Patients who received medical treatment alone or incomplete removal exhibited progression in their neurological deficits and their seizures could not be controlled. Medication with praziquantel seemed to have no killing effect on live worms. The authors conclude that MR imaging is the most valuable modality for the early detection of cerebral sparganosis and that complete surgical removal of granuloma together with worms, whether they are alive or degenerative, is the treatment of choice.

Adolescent↗
PubMed1996

Terminal myelocystocele--a case report.

Terminal myelocystocele is a rare form of occult spinal dysraphism in which the hydromyelic caudal spinal cord and the subarachnoid space are hemiated through a posterior spina bifida. A 1.5 month old boy presented with a large lumbosacral mass and urinary incontinence. The magnetic resonance imaging, operative findings and pathological findings revealed a low lying conus with a dilated central canal dorsally attached to the subcutaneous tissue. Ventral subarachnoid space was enlarged and herniated through the laminar defect of the sacrum. The lesion was typical of a terminal myelocystocele. The clinical features are different from those of myelomeningocele in many aspects. Though the incidence is low, terminal myelocystocele should be included in the differential diagnosis of congenital lesions presenting as a lumbosacral mass.

Arachnoid↗
PubMed1996

Experimentally induced Chiari-like malformation with myeloschisis in chick embryos.

Though several pathogenetic theories concerning the frequent association of Chiari malformation and hydrocephalus with myeloschisis have been suggested, none of them explains all the aspects of the disorder. To investigate whether myeloschisis is the direct cause of Chiari malformation and hydrocephalus or these conditions are the results of another basic event, we observed the morphological changes of the posterior cranial fossa and its components in the chick embryos with surgically induced myeloschisis. To make myeloschistic lesions, we opened the neural tube for a length of 9-11 somites in Hamburger and Hamilton stage 16-19 chick embryos. They were divided into cervicothoracic (C-T) and lumbosacral(L-S) groups according to the area of incision. The embryos were re-incubated until postoperative day 11. In the control group, embryos were incubated with the eggshell window open as their experimental counterparts. The survival rates of each group were as follows; 11% (9 survivors/85 operated embryos), 8% (7/83), and 17% (10/60) in the C-T, L-S and control groups, respectively. Myeloschisis positive rates were 100% in the operated groups and 0% in the control group. The heads of embryos were sectioned along the sagittal plane to observe the morphological changes in the posterior cranial fossa and its components. Of the survivors, five in the C-T group, two in the L-S group and six in the control group were available for light microscopic inspection. In the majority of embryos with myeloschisis, without difference between the C-T and L-S groups, the fourth ventricles were smaller than those of the control group and the subarachnoid spaces in the posterior cranial fossa were also narrower. In embryos with severe changes, the cerebellum displaced downward comparing with that of the control embryos. No evidence of hydrocephalus was present Though not always typical, morphological changes similar to Chiari malformation were observed in chick embryos with surgically induced myeloschisis. It suggests a strong direct causal relationship between the two conditions and supports the theories of derangements in cerebrospinal fluid dynamics rather than those of primary mesenchymal or neural origin as a pathogenetic mechanism of Chiari malformation.

Animals↗
PubMed1995

Morphological study of surgically induced open neural tube defect in old (14 and 21 days) chick embryos.

As an experimental model for the research of open neural tube defect (NTD), the surgical model has several advantages over others, in spite of the fact that the pathogenetic mechanism is not compatible with the human intrauterine events. To make reproducible NTDs by surgery and to compare the surgically induced lesions with the human myeloschisis morphologically, we opened the neural tube for a length of 9-11 somites in Hamburger and Hamilton stage 16-19 chick embryos. Embryos which survived until the late in ovo life (total age 14 and 21 days) showed relatively reproducible open NTDs. Morphologically they are similar to human myeloschisis. This study suggests that the surgical model can be suitable for studies of open NTDs.

Age Factors↗
PubMed1995

Intractable seizures associated with brain tumor in childhood: lesionectomy and seizure outcome.

The authors retrospectively reviewed ten pediatric brain tumor patients with intractable seizures who underwent lesionectomy without intentional identification and resection of the epileptogenic region to assess the clinical features and seizure outcome after lesionectomy in such patients. Seizures were complex partial in seven cases and simple partial, absence, and generalized tonic-clonic in one case each. Tumors were located at the medial temporal lobe in four cases, at the frontal lobe in four cases, at the parietooccipital and the suprasellar areas in one case each. The most common pathology was benign oligodendroglioma (five cases) followed by ganglioglioma (two cases). Others were pleomorphic xanthoastrocytoma, hamartoma, and primitive neuroectodermal tumor (one case each). In four cases, complete removal of the tumor was feasible. Postoperatively nine of the ten patients showed favorable seizure control (Engel's classification 1 and 2) and of these, six were seizure-free during the follow-up period (mean duration: 40 months). Therefore, lesionectomy can be an appropriate initial treatment for patients with brain tumor and medically intractable seizures.

Adolescent↗
PubMed1995

Proximal migration and subcutaneous coiling of a peritoneal catheter: report of two cases.

The authors report two cases with a rare complication of ventriculoperitoneal shunt. The peritoneal catheters migrated upward to the scalp and to the clavicular area. In one case, the whole length of the peritoneal catheter was pulled out from the peritoneal cavity and was coiled subcutaneously. Both of the patients had the habit of head rotation and one of the patients had a history of subcutaneous fluid collection at the site of coiling. At surgery, whitish inflammatory granulation tissues were noted around the catheter in both cases, which might act as an anchoring point for the "windlass effect".

Child, Preschool↗
PubMed1995

Infarction of the territory supplied by the contralateral superior cerebellar artery in a case of descending transtentorial herniation.

Infarction of the territory supplied by the contralateral superior cerebellar artery in cases of descending transtentorial herniation has not been reported. The authors experienced a primitive neuroectodermal tumor in a patient whose consciousness deteriorated transiently due to descending transtentorial herniation. On the magnetic resonance imaging taken 8 days after the herniation, lesions thought to be infarction of territories supplied by the ipsilateral posterior cerebral artery and the contralateral superior cerebellar artery were noted. The possible mechanism of this peculiar pattern of infarction is discussed.

Arteries↗
PubMed1995

Functioning periods and complications of 246 cerebrospinal fluid shunting procedures in 208 children.

To investigate the functioning periods and the causes of cerebrospinal fluid shunt failures, 246 shunts inserted in 208 children from October 1985 to August 1992 at the authors' institute were retrospectively reviewed. The mean age at shunt insertion was 4.0 years and the reasons for the shunting procedures were congenital hydrocephalus (47.6% per procedure), tumor-associated hydrocephalus (21.1%), postmeningitic hydrocephalus (11.8%), congenital cyst (10.6%) and others (8.9%). All except 2 were shunted to the peritoneal cavity. Forty-five operations for shunt failure were done (18.3%) during the follow-up period (mean, 32 months). The functioning (shunt survival) rates at 6, 12, 24 and 36 months after surgery were 91.6%, 86.6%, 83.6% and 82.9%, respectively. The complications were mechanical malfunction (12.2%), infection (4.1%), subdural fluid collection which required drainage (1.6%) and migration (0.4%). About half of the mechanical malfunctions and infections which had occurred during the follow-up period were within 6 months and 2 months after surgery, respectively. There was no shunt-related mortality. These chronological data should be considered in the planning of follow-up schedules.

Adolescent↗
PubMed1994

Synthesis of steroid intermediates via alkylation of dianion derived from acetoacetic ester.

A synthetic route for A-ring aromatic steroid intermediates starting from alkylation of dianion derived from acetoacetic ester with m-methoxyphenylethyl bromide to form benzene ring connected to a linear six-carbon fragment is described. This unit, after chemical modifications to 5, was condensed with 2-methylcyclopentan-1,3-dione (6a) to form prochiral trione, 7a, a key synthetic intermediate in A-ring aromatic steroid. Microbial reduction of 7a with Schizosaccharomyces pombe (NRRL Y-164) gave chiral (-)-11 in 65% yield. Starting from 2,2-dimethylsuccinic acid, 2,4,4-trimethylcyclopentan-1,3-dione (6a) was prepared, which was condensed subsequently with 5 to form racemic 7b trione intermediate. Asymmetric cyclization of 7b in the presence of L-(-)-phenylanlanine, followed by acidic cyclization led to regiospecific synthesis of 16,16-dimethyl tetracyclic steroid intermediate.

Acetoacetates↗
PubMed1994

Treatment outcome and prognostic factors of medulloblastoma.

Medulloblastoma, once a tumor with a dismal prognosis, is one of the most common primary brain tumors of childhood. As the methods of treatment have been continuously refined, the outcome has improved remarkably during the last few decades. The outcome of 78 medulloblastoma patients, which were managed from 1972 to 1992 at the Department of Neurosurgery of Seoul National University Hospital, were analyzed to calculate the 3-year and 5-year survival rates (3yS and 5yS). Of those, 52 cases which were treated after July 1982 were studied 1) to calculate the 3yS and 5yS, 2) to figure out the prognostic factors of survival, and 3) to investigate the role of adjuvant chemotherapy ('8-drugs-in-a-day' protocol: CCNU, cisplatin, vincristine, hydroxyurea, procarbazine, cytosine arabinoside, methylprednisolone and cyclophosphamide). The 3yS and 5yS of the 78 patients were 57.4% and 47.3%, respectively. Of the 52 patients treated after July 1982, the 3yS and 5yS were 67.8% and 64.1%, respectively. The latest recurrence was at 56 months after surgery. All the recurrences were within the risk period of Collins' rule. Of the prognostic factors studied by univariate analysis (age, sex, Chang's classification T- and M-stages, extent of surgical removal, and chemotherapy), Chang's classification M-stage and sex were the statistically significant factors (p = 0.028 and 0.024 respectively). On multivariate analysis, only the M-stage was statistically significant (p = 0.004). Adjuvant chemotherapy had different influences in different patient groups. Only in the 'poor risk' group, did adjuvant chemotherapy have a strong tendency to better outcome (p = 0.069). Further data collection and analysis will lead to better treatment modalities and better outcome for this most common primary malignant brain tumor in childhood.

Adolescent↗
PubMed1994

Morphological study of surgically induced open neural tube defects in chick embryos--postoperative 24 hours.

For the experimental study of neural tube defect (NTD), a surgical model has advantages over other models in a few aspects. It causes less functional derangement of cells and the NTDs can be made selectively by surgery. The authors planned to use the surgical model for the experimental study of NTD. As the first step for the studies, the chronological changes of morphology during the early postoperative period were investigated using postincubation 3-day chick embryos. The objectives of this study are (1) the morphological evaluation of the surgical model as a method for studies of open NTD, and (2) the observation of morphological changes for the first 24 hours after surgery which include 'overgrowth' appearance and the continuity between the surface ectoderm and the neuroectoderm. The morphological changes were observed by light microscope and scanning electron microscope. Immediately after surgery, typical open NTDs were observed. Morphologically they were very similar to the appearance of spontaneous (non-surgical) open NTDs. The opened neural tubes were everted progressively and they looked rather flat at 24 hours after surgery. Cellular hyperplasia ('overgrowth' appearance) was noted within 24 hours after surgery and became more prominent during the 24 hours. There was increasing continuity between the surface ectoderm and the neural tissue until 24 hours after surgery when the continuity looked almost complete. In conclusion, surgically induced NTDs are morphologically very similar to spontaneous NTDs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Diastematomyelia--clinical manifestation and treatment outcome.

Diastematomyelia is a rare congenital anomaly characterized by a division of the spinal cord or the filum terminale into two parts. In Korea, only one case has been reported. The authors have operated on 5 cases of diastematomyelia with septum since July, 1978. The ages ranged from 1 to 44 years (median; 11 years). There were 2 boys, 2 girls and an adult man. The disease manifested by cutaneous abnormalities and neurological or orthopedic deficits. Pain was a chief complaint in the adult patient. The symptoms had progressed in 3 cases. The diagnosis was made correctly by CT myelography or MRI in 4 cases. The median septum was located at the lumbar area in 4 cases and at the lumbosacral region in 1 case. Associated abnormalities included low lying conus (5 cases), lipoma (2 cases), thickened filum terminale (1 case), hemilipomyelomeningocele (1 case) and syrinx (1 case). The median septum was removed. The dural sleeve adjoining the septum was resected and the dural sac was reconstructed. The role of MRI in the diagnosis and planning of surgery and the high frequency of associated low lying conus were emphasized. Though the surgical treatment relieved pain, it did not reverse the neurological deficits or orthopedic deformities significantly, which suggests the beneficial effects of early surgical intervention in the cases with progressive symptoms.

Adolescent↗
PubMed1994

Successful treatment of hereditary progressive dystonia--a case report.

Hereditary progressive dystonia or Segawa disease is a very rare disease. Diagnosis depends on typical clinical features with remarkably good response to levodopa and normal laboratory findings. Here, we report on a unique case of Segawa disease with a fixed equinovarus foot. The patient was a twenty one year old female with the typical clinical manifestations since eight years of age who became wheel-chair dependent at the age of fifteen. The dystonia responded well to levodopa except for the foot deformities. The foot deformities were successfully corrected by use of the Ilizarov apparatus and she ambulated freely at follow up. Since several similar foot deformities appeared in the early stage of a progressive neurological degenerative disease, the treatable Segawa disease should be added to the differential diagnosis when facing a patient with pes equinovarus.

Adult↗
PubMed1994

Irreducible volar rotatory dislocation of the proximal interphalangeal joint.

Volar rotatory dislocation of the proximal interphalangeal (PIP) joint often cannot be reduced by closed manipulation because of interposition of soft tissues. In this case, the condyle of the proximal phalanx was trapped between the central slip and the lateral band. This case is reported to reemphasize the importance of recognizing serious injuries involving the soft tissues around the PIP joint. Deprival of its normal dorsal stabilizing forces can cause a loss of both static and dynamic joint support. Secondary scarring and contractures affect all damaged structures of the joint.

Adult↗
PubMed1994

Intercondylar fractures of the distal humerus: routine anterior subcutaneous transposition of the ulnar nerve in a posterior operative approach.

Intercondylar fractures of the distal humerus in adults are rare and notoriously difficult to treat. The goals of open reduction are to preserve the articular surface and restore elbow function. We treated 20 patients by open reduction with dual-plate internal fixation and routine anterior subcutaneous transposition of the ulnar nerve. The follow-up period ranged from 15 to 35 months. The fractures were classified according to Muller's system. The results were evaluated using the Cassebaum rating system and subjective functional status. Excellent or good results were achieved in 15 elbows (75%), two had a fair result, and three, poor. A clearer understanding of fracture patterns, rigid dual-plate internal fixation, and early rehabilitation are needed to improve the results from this vexing injury. We recommended routine ulnar nerve anterior subcutaneous transposition using a posterior approach. Compared with published reports, our preliminary results demonstrated no postoperative ulnar nerve compression syndrome at follow-up. Routine anterior subcutaneous transposition of the ulnar nerve to avoid the postoperative ulnar nerve compression syndrome is required.

Adult↗