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Biomedical subjects

T T Wong

Publications and source records attributed to T T Wong.

At least 19 recordsLinked to original sources
PubMed1998

MIB-1 labeling index in nonpilocytic astrocytoma of childhood: a study of 101 cases.

BACKGROUND: The prognosis of pediatric patients with nonpilocytic astrocytoma, and in particular those with anaplastic astrocytoma, is somewhat unpredictable. This study used MIB-1 monoclonal antibody, a proliferative marker that can be used in formalin fixed paraffin embedded tissues, to study nonpilocytic pediatric astrocytoma. METHODS: Astrocytoma, anaplastic astrocytoma, and glioblastoma specimens excised from a total of 101 pediatric patients during the period from January 1975 to September 1996 were retrieved from the authors' surgical pathology file. Histologic grading of the specimens was performed based on a modified Ringertz system. The proliferative potential of the tumors was estimated by using the MIB-1 labeling index (LI), which was evaluated with morphologic grades of tumors and survival of the patients. RESULTS: Of the 101 patients, 34 had astrocytoma, 33 had anaplastic astrocytoma, and 34 had glioblastoma. Their mean survival times were 165.2+/-14.9 months (mean+/-standard error; SE), 46.1+/-9.9 months, and 21.8+/-5.6 months, respectively. The mean MIB-1 LI of different tumor grades were as follows: astrocytoma, 3.9+/-4.3 (mean+/-standard deviation; range, 0.0-21.6); anaplastic astrocytoma, 24.3+/-15.6 (range, 1.7-62.8); and glioblastoma, 35.9+/-16.4 (range, 7.36-63.3). The mean survival of the entire group of patients with LIs < or = 11 was 173.2+/-12.2 months (mean+/-SE), and the mean survival of those with LIs > 11 was 20.3+/-4.1 months. The survival of anaplastic astrocytoma patients with LIs < or = 11 was similar to that of astrocytoma patients, whereas the survival of anaplastic astrocytoma patients with LI > 11 was similar to that of patients with glioblastoma. CONCLUSIONS: The results of the current study show that histopathologic grading can predict the outcome for patients with astrocytomas and glioblastomas, whereas MIB-1 LI can separate better and worse prognostic groups in patients with anaplastic astrocytoma.

Adolescent↗
PubMed1998

Prognostic factors and therapeutic options of radiotherapy in pediatric brain stem gliomas.

BACKGROUND: A retrospective analysis was made to clarify the relationship between prognosis, radiation dose and survival of brain stem gliomas. METHODS: From 1983 to 1995, 22 children with brain stem tumors were treated by radiotherapy in the Veterans General Hospital-Taipei. Twelve patients had pathology proof and the remainder were diagnosed by computerized tomography and/or magnetic resonance imaging. Seven patients had postoperative radiotherapy. Fifteen patients had radiotherapy as primary management, five of whom had adjuvant chemotherapy. All patients received 4000-7060 cGy, either in conventional daily or hyperfractionated twice daily radiotherapy. Survival from date of diagnosis was calculated by the Kaplan-Meier method. Univariate analyses and multivariate analyses were calculated by the log rank test and the Cox proportional hazard model, respectively. RESULTS: Most patients showed improvement following treatment. The overall 2-year survival rate was 55.5% with a median survival of 27.1 months. Two-year survival for patients with primary management of operation and radiotherapy (n = 7), radiotherapy alone (n = 10) and radiotherapy with adjuvant chemotherapy (n = 5) were 66.7, 50 and 53.3%, respectively. In univariate analysis, the study revealed that the growth pattern of tumors and the simultaneous presence of cranial neuropathy and long tract sign were significant prognostic factors (P = 0.017 and 0.036). A trend of better outcome with radiation dose > 6600 cGy and the hyperfractionation scheme was also noted in our study (P = 0.0573 and 0.0615). However, only the hyperfractionation scheme was also noted in our study (P = 0.0573 and 0.0615). However, only the hyperfractionation scheme showed significance in multivariate analyses (P = 0.0355). Survival was not significantly affected by age, gender or method of diagnosis. CONCLUSION: Radiotherapy appears to be an effective treatment modality of brain stem tumors. Patients with both cranial neuropathy and long tract signs had a poorer outcome. Hyperfractionated radiotherapy may give better local control and lead to better survival.

Brain Neoplasms↗
PubMed1997

Neuropsychological sequelae after treatment for medulloblastoma in childhood--the Taiwan experience.

The purpose of this study was to investigate the functional independence, intellectual performance and academic achievement of children treated for medulloblastoma at the Veterans General Hospital-Taipei. Adverse factors that it was thought would result in significant intellectual impairment were also studied. Nineteen patients with medulloblastoma located over the posterior fossa were enrolled in this study. Their mean age at tumor removal was 6.16 +/- 3.30 (range 2-14) years. Mean full intelligent quotient (FIQ) was 86.00 +/- 22.66, performance intelligent quotient (PIQ) was 85.29 +/- 21.23, and verbal intelligent quotient (VIQ) was 90.50 +/- 23.50. In 11 cases academic achievement at school was poor. Sixteen patients received radiation therapy after tumor removal. Significant negative correlations were noted between IQ and whole-brain irradiation dose (r = -0.72) and between IQ and years after radiation therapy (r = -0.63). The results indicate a need for ongoing attention and intervention to prevent, remedy or minimize deficits produced by the tumor itself and by the cancer treatment.

Achievement↗
PubMed1997

Primary cerebellar extramedullary myeloid cell tumor mimicking oligodendroglioma.

Extramedullary myeloid cell tumors (EMCTs) are tumors consisting of immature cells of the myeloid series that occur outside the bone marrow. Most of them are associated with acute myelogenous leukemia or other myeloproliferative disorders, and a small number occur as primary lesions, i.e., are not associated with hematological disorders. Occurrence inside the cranium is rare, and there has been only one case of primary EMCT involving the cerebellum reported in the literature. The case we report here is a blastic EMCT occurring in the cerebellum of a 3-year-old boy who had no signs of leukemia or any hematological disorder throughout the entire course. The cerebellar tumor was at first misdiagnosed as an "oligodendroglioma" because of the uniformity and "fried egg" artifact of the tumor cells. The tumor disappeared during chemotherapy consisting of 12 treatments. However, it recurred and metastasized to the cerebrospinal fluid (CSF) shortly after the therapy was completed. A diagnosis of EMCT was suspected because of the presence of immature myeloid cells in the CSF, and was confirmed by anti-myeloperoxidase and anti-lysozyme immunoreactivity of the cerebellar tumor. The patient succumbed 1 year and 3 months after the first presentation of the disease.

Cerebellar Neoplasms↗
PubMed1996

Interaction of 4-tert-butyl-[3-(2-chloroethyl) ureido] benzene with phosphatidylcholine bilayers: a differential scanning calorimetry and infrared spectroscopy study.

We have investigated the interaction between a new antineoplastic drug, 4-tert-butyl-[3-(2-chloroethyl)ureido] benzene (tBCEU), and distearoylphosphatidylcholine bilayers using differential scanning calorimetry, Fourier transform infrared spectroscopy (FT-IR), and high-pressure infrared spectroscopy. The results obtained with the three different techniques indicate that the drug incorporates in the lipid bilayer. More specifically, the incorporation of the tBCEU results in a decrease in the phase transition temperature of the lipid and in an increase in the amount of gauche conformers in the liquid-crystalline phase. In the gel phase, high-pressure FT-IR results indicate that the incorporation of tBCEU decreases the acyl chain packing. In addition, the results suggest the presence of hydrogen bonding between the lipid carbonyl group and a hydrogen bond donor in the tBCEU molecule. A possible candidate for this donor is the NH group adjacent to the phenyl ring. A model is proposed for the incorporation of tBCEU in lipid bilayers, with the hydrophobic portion of the drug intercalated between the lipid bilayers and the hydrophilic region located close to the interfacial region of the bilayer.

Antineoplastic Agents↗
PubMed1996

A method of enlarging the opening of the third ventricular floor for flexible endoscopic third ventriculostomy.

In the Pediatric Neurosurgical Service of the Veterans General Hospital, Taipei, flexible endoscopic III ventriculostomy has been applied in children with noncommunicating hydrocephalus and periaqueductal/pineal tumor. We modified the technique to allow enlargement of the opening of the III ventricular floor. The use of an Atlas Wire Stone Extractor for this purpose is described.

Biopsy↗
PubMed1996

Quality of life and life satisfaction in families after a child has undergone corpus callostomy.

Epilepsy is a chronic neurological condition which can have a detrimen tal effect on patients' quality of life (QOL). We evaluated the overall satisfaction with QOL and changes in QOL in 25 families with children who had undergone corpus callostomy for severe epilepsy. The mean age of seizure onset was 3.4 years, and the mean period from seizure onset to operation was 5.2 years. Mean follow-up was 19.3 months. Twenty of 22 patients had various degrees of mental retardation. Mean reduction in severity of seizure activity was 64%. Nineteen of 25 (76%) parents were satisfied with the surgical result. Eighteen of 25 parents (72%) described a good level of satisfaction with their families QOL after callostomy. Reduction in severity of seizure activity was significantly correlated with how successful families considered the surgery to be and how satisfied they were with their QOL (r = 0.72 and 0.77, respectively). Life domains showing one greatest improvement after callostomy included level of self-care, family life, and school performance. Improvements in level of self-care, family life, and school performance were associated with higher levels of life satisfaction (r = 0.69, 0.60, and 0.59, respectively). Hyperactivity, attention span, and social skills improved significantly in 11 patients after surgery. Callostomy did not improve mental performance. We conclude that improved seizure control after callostomy is also associated with improved QOL.

Achievement↗
PubMed1995

Combination chemotherapy with vinblastine, bleomycin, cisplatin, and etoposide (VBPE) in children with primary intracranial germ cell tumors.

We have treated 13 children with primary intracranial germ cell tumors with the combination of vinblastine, bleomycin, cisplatin, and etoposide, the so-called VBPE regimen in the past seven years at one institution. The clinical diagnosis of these children were: three germinomas, seven non-germinomatous germ cell tumors, and three recurrent non-germinomatous germ cell tumors without previous chemotherapy. Of this group, three germinomas and three non-germinomatous germ cell tumors were treated primarily with VBPE plus radiotherapy. All of them responded completely, and were free of tumor. Primary VBPE regimen without radiotherapy was used in another four non-germinomatous germ cell tumors. After six courses of VBPE regimen, only one of the four patients achieved complete response for 30 months. VBPE regimen was used as salvage chemotherapy in three recurrent non-germinomatous germ cell tumors without previous chemotherapy. After six courses of VBPE regimen, two had complete response for 58+ months and 78+ months respectively. We concluded that in newly-diagnosed intracranial non-germinomatous germ cell tumors, the combination of chemotherapy VBPE regimen and radiotherapy led to good results. Primary chemotherapy with VBPE alone was not adequate for the treatment of non-germinomatous germ cell tumors. However, VBPE regimen might be one of the salvage therapies for recurrent germ cell tumors without chemotherapy before relapse.

Adolescent↗
PubMed1995

Familial neurofibromatosis 1 with germinoma involving the basal ganglion and thalamus.

Intracranial germinoma associated with neurofibromatosis 1 (NF-1) has never been documented previously. We report a case of familial NF-1 with a germinoma involving the right basal ganglion and thalamus. A 12-year-old boy presented with multiple café-au-lait spots and a family history of neurofibromatosis in his mother, one of two siblings, and his maternal grandfather. His intracranial lesion was subtotally resected. Histologically, it was a pure germinoma. Serum alpha-feto protein and beta-human chorionic gonadotropin levels were within the normal range. Postoperative myelographic examination and cerebrospinal fluid cytology study showed no evidence of subarachnoid seeding. The patient received postoperative combination chemotherapy resulting in complete response and clearance of the residual tumor. Although this finding of an intracranial germinoma in a patient with familial NF-1 may be coincident, it is suggestive of a potential genetic predisposition. Longitudinal evaluation for the possibility of neoplasm, especially germ cell tumor, in basal ganglion lesions in NF-1 patients is necessary.

Basal Ganglia↗
PubMed1995

Audit of basal cell carcinoma in Princess Margaret Hospital, Hong Kong: usefulness of frozen section examination in surgical treatment.

A retrospective study was undertaken of 64 Chinese patients with primary (previously untreated) basal cell carcinoma (BCC) surgically treated by the plastic and reconstructive surgery team at the Princess Margaret Hospital, Hong Kong, from January 1988 to March 1994. Sixty-three (98%) were in the head and neck region, half on the nose. It was equally common in men (mean age 69 years) and women (mean age 67). Two women (3%) were younger than 35. The rate of complete excision increased after the introduction of frozen section examination. A complete excision rate of 89% (n = 57) was achieved by 1994. We conclude that frozen section examination should be done routinely in patients having BCC excised.

Adult↗
PubMed1995

Lumboperitoneal shunt complicated with chronic tonsillar herniation: a case report.

Lumbopritoneal shunt (L-P shunt) has been widely accepted as a treatment for communicating hydrocephalus. The technique offers many advantages such as easy insertion, a low infection rate, a reduced incidence of brain damage, et centera. Despite these advantages, there are also some associated complications, such as tonsillar herniation. This complication rarely occurs, but, when it does, it develops gradually. This report concerns an eight-year-old girl, who had received L-P shunt at the age of 20 days; she then developed tonsillar herniation, requiring operative decompression, eight years later. This case illustrates the necessity for carefully follow up patients who have undergone the L-P shunt procedure.

Cerebellar Diseases↗
PubMed1995

Hypothalamic hamartoma and gelastic epilepsy: a case report.

We studied a 6-year-old girl who presented with inappropriate and uncontrollable laughing episodes since age 3. Physical examination revealed a precocious puberty. The luteinizing hormone-releasing hormone (LH-RH) stimulation test showed an increased level of follicle-stimulating hormone (FSH). The interictal electroencephalogram (EEG) was normal. Several laughing fits were documented during video/EEG monitoring. During laughing, the ictal EEG showed a diffuse suppression of background rhythm, prominent over the left mesial temporal region. A mass lesion about 2 x 2 cm in size was found over the suprasellar cistern with a broad base attached to the hypothalamus, which was isodense on a computed tomography (CT) scan, isointense to gray matter on T1-weighted magnetic resonance (MR) imaging and hyperintense on T2-weighted MR imaging. The findings were suggestive of a hypothalamic hamartoma. A variety of anticonvulsants had been used with little or no response to the frequency or duration of the laughing seizures.

Child↗
PubMed1995

Unilateral porencephalic cyst presenting as infantile spasms: a case report.

Multiple etiological factors have been associated with infantile spasms (IS), and are usually linked to diffuse or multifocal brain damage. It is generally believed that infants with symptomatic IS have a significantly higher incidence of mental retardation and epilepsy than those with cryptogenic IS. However, IS secondary to focal brain lesions in which surgical removal of the lesions has resulted in cessation of generalized spasms and subsequent normal development are rarely reported. A seven-month-old male infant who manifested head nodding and generalized flexor spasms one month prior to the admission is reported. Waking interictal electroencephalography revealed a pattern of burst-suppression variant of hypsarrhythmia. Brain magnetic resonance imaging disclosed a huge porencephalic cyst over the left temporo-parietal region. The infant underwent craniotomy with corpus callosotomy, causing marked improvement in seizures. He attained subsequent stable psychomotor development.

Brain Diseases↗
PubMed1995

Startle epilepsy presenting as drop attacks: a case report.

A case of startle epilepsy, induced by an unexpected touch on the left shoulder of a 3.5 year old boy, was investigated. The startle epilepsy manifested as an atonic drop attack. Neurological examination revealed a mild hemiparesis on the left side. Computed tomography (CT) scanning demonstrated an enhancement over the right parieto-frontal region, suggesting a hemangioma. Interictal electroencephalography (EEG) showed diffuse slowing and asymmetry of background activities with lower amplitude over the right centro-parieto-temporal region. The ictal EEG showed a paroxysmal bilaterally synchronized high amplitude single spike followed by a few slow waves lasting about one second over the bilateral centro-parieto-temporal regions. The seizure resisted anticonvulsant therapy and no significant responses were observed despite the use of combined therapy with valproic acid, phenytoin, primidone and clonazepam.

Child, Preschool↗
PubMed1994

Thermoregulatory effects of resiniferatoxin in the rat.

When administered acutely, the vanilloid (capsaicin) receptor agonist resiniferatoxin induces marked hypothermia in the ferret, rat and mouse. The aim of this study was to further characterise the thermoregulatory effects of resiniferatoxin in the rat in an attempt to understand the mechanism by which resiniferatoxin induces this hypothermic effect. Three doses of resiniferatoxin were administered (50, 100, 200 micrograms/kg s.c.) in separate animals at an ambient temperature (Ta) of 20 degrees C but there was no apparent dose-related effect on the decrease in colonic temperature over this range. Resiniferatoxin (50 micrograms/kg s.c.) decreased whole body oxygen consumption when measured below thermoneutrality (Ta = 20 degrees C) but not at thermoneutrality (Ta = 29 degrees C); likewise there was no hypothermic response to resiniferatoxin when measured at a Ta of 29 degrees C. Operant responding for radiant heat in a cold environment (-8 degrees C) was also measured in resiniferatoxin-treated (50 micrograms/kg s.c.) rats. These experiments showed that resiniferatoxin-treated rats attempted to defend body temperature by lever pressing for more radiant heat. However, this was not sufficient to reverse the hypothermia. Two repeat doses, 1 week apart, had little or no effect on colonic temperature, oxygen consumption or operant responding in the cold. Resiniferatoxin (50 micrograms/kg s.c.) also produced hypothermia (Ta = 20 degrees C) in neonatally capsaicinized adult rats. The exact site and mode of action is still under investigation, but it is postulated that resiniferatoxin activates, and then destroys or desensitizes warm thermoreceptors.

Animals↗
PubMed1994

Effects of nucleotide sequence on the specificity of rne-dependent and RNase E-mediated cleavages of RNA I encoded by the pBR322 plasmid.

RNase E, an endoribonuclease encoded by the Escherichia coli ams/rne/hmp1 locus, cleaves RNA I, an antisense regulator of the replication of ColE1 type plasmids, in a single-stranded region near its 5' end. The rne-3071 mutation prolongs the RNA 1 half-life in cells cultured at an elevated temperature and imparts temperature sensitivity on RNase E isolated from the mutant strain. Here we report the effects of specific sequence changes introduced by site-directed mutagenesis on the location of ribonucleolytic cleavage near the 5' end of pBR322 RNA I in rne-3071 and congenic rne+ E. coli and on cleavage of RNA I by RNase E in vitro. Primer extension analyses showed that the occurrence and position of cleavages in vivo and in vitro are altered highly specifically by sequence changes but that the site of cleavage bears no simple relationship to a particular nucleotide order. Our results do not support either the notion that cleavage by RNase E is determined by a consensus sequence or the contrary view that RNase E is a virtually nonspecific single-stranded endonuclease with a preference for cutting 5' to an AU dinucleotide.

Base Sequence↗