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L C Ang

Publications and source records attributed to L C Ang.

66 records · Page 4Linked to original sources
PubMed1990

An immunohistochemical study of papillary tumors in the central nervous system.

An immunohistochemical study was performed on the paraffin sections of 25 tumors in the central nervous system (CNS) with prominent papillary configurations. These tumors included seven metastatic papillary carcinomas, six choroid plexus tumors, four papillary ependymomas, two myxopapillary ependymomas, two papillary pituitary adenomas, two astroblastomas, one papillary meningioma, and one anaplastic astrocytoma with significant papillary changes. The panel of antibodies applied included anti-glial fibrillary acidic protein (GFAP), anti-carcinoembryonic antigen (CEA), anti-vimentin (VM), anti-S-100 protein (S-100 P), anti-cytokeratin, and anti-prealbumin antisera. All ependymomas and astroblastomas examined expressed both VM and GFAP, which were either absent or focally expressed in choroid plexus tumors. In contrast, all choroid plexus tumors showed anti-cytokeratin immunoreactivity that was absent in the ependymomas and astroblastomas. Five choroid plexus tumors also expressed S-100 P, thus differentiating them from metastatic carcinoma that showed negative immunostaining. Anti-CEA antisera immunoreactivity was seen in six metastatic tumors, whereas none of the primary CNS tumors expressed CEA. Prealbumin was expressed in four choroid plexus tumors and two metastatic tumors. Immunohistochemical typing using a panel of antibodies has allowed the differentiation of most of the papillary tumors in the CNS examined in this study.

Astrocytoma↗
PubMed1990

Autopsy samples of Alzheimer's cortex show increased peroxidation in vitro.

The formation of thiobarbituric acid-reactive products was measured as an index of peroxidation by oxygen free radicals in homogenates of frontal cortex and cerebellum from brains taken at autopsy and verified histologically as being Alzheimer's (n = 6) or normal (n = 6). Compared with controls, basal peroxidation is significantly higher in Alzheimer's cortex, and this difference is also evident in the presence of exogenous iron. Peroxidation in cerebellum and levels of total glutathione, RNA, and DNA in cortex and cerebellum do not differ significantly between Alzheimer's brain and controls. Iron-induced peroxidation in cortex is reduced by the lazaroid U-74500A, with calculated IC50 values that are significantly higher in Alzheimer's samples (10 microM) than in controls (2.5 microM). These observations suggest that cerebral cortex from Alzheimer's patients differs from controls with respect to in vitro peroxidation.

Aged↗
PubMed1989

Neuropathology of heart transplantation.

The neuropathology of 18 cardiac transplant recipients was reviewed with the clinical findings. Pathological changes were noted in the central nervous system (CNS) in 94% of the patients, the most frequent being cerebral vascular in origin (72%). Eight patients (44%) had multiple cerebral infarcts and morphologically, a large number of these antedated the transplantation. In addition 4 patients had acute focal ischemic changes which occurred after transplantation. Intracranial hemorrhage was noted in 5 patients (28%), including one case of fatal intracerebral hemorrhage following an acute hypertensive episode after the transplantation. While systemic infection was common (10 patients), there were only 5 cases of intracranial infection; including 3 cases of cytomegalovirus infection, one of candidiasis and one of aspergillosis. Post-transplant seizures, occurring in a third of the patients, were related to a variety of causative factors such as sepsis, intracranial hemorrhage, cerebral ischemia, metabolic encephalopathy and cyclosporin neurotoxicity. Of note in this series was the absence of CNS lymphoma or other systemic lymphoproliferative disorder.

Adolescent↗
PubMed1988

Myopathy in primary systemic amyloidosis.

Involvement of the peripheral nervous system by amyloidosis is common. It is less well recognized that amyloid can directly infiltrate and weaken skeletal muscle. We report a case of a 73-year-old woman, known to have cardiac amyloidosis, who developed profound weakness secondary to amyloid myopathy. Review of the 8 other well documented cases in the literature has revealed a rather homogeneous syndrome. Proximal weakness, muscle stiffness, pseudohypertrophy and myalgia constitute the principal features. This syndrome usually develops in cases with well recognized generalized amyloidosis. Amyloid is deposited within the basal lamina of blood vessels and muscle fibers.

Aged↗
PubMed1986

Severe cerebellar degeneration in a patient with T-cell lymphoma.

A 53-year-old man with an aggressive T-cell lymphoma was found at autopsy to have severe cerebellar degeneration, presumably as a 'remote' effect of malignancy. The degree of cerebellar atrophy was unusually pronounced and widespread, involving both Purkinje cell and granule cell layers, although patches of preserved and essentially normal cerebellar cortex were identified. This case is of particular interest in view of data which indicate that cerebellar Purkinje cells and T-lymphocytes share antigenic surface markers.

Atrophy↗
PubMed1985

Inappropriate luteinizing hormone concentration in human breast cancer.

As part of a programme to assess the para-endocrine behaviour of human infiltrating ductal breast carcinoma among Chinese women, this study was designed to compare (Mann-Whitney U test) the immunoreactive mammary tumour tissue concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH), human chorionic gonadotrophin (beta-hCG) and prolaction (PRL) at stages I (n = 9), II (n = 12) and III (n = 7) with that of normal breast tissue (n = 8). It was found that with the exception of FSH and beta-hCG in stages I and III significantly elevated concentrations of protein hormones were noted at all stages of malignancy. The possible importance of these findings in multi-stage mammary carcinogenesis is discussed. It is suggested that measurement of LH concentration may provide an endocrine basis to facilitate the diagnosis of tumours to serve as a guide to the biological behaviour of mammary neoplasms.

Adult↗
PubMedDate not supplied

MRI monitoring of interstitial microwave-induced heating and thermal lesions in rabbit brain in vivo.

The purpose of this experiment was to use MRI to monitor microwave heating and thermal damage of brain tissue in vivo. Interstitial microwave antennas were implanted into the cerebral hemispheres of seven anesthetized rabbits. Variable power of 30 to 100 W was applied for periods of 5 to 15 minutes and tissue temperature was monitored continuously. MR images were obtained throughout the procedure at 20-second intervals, using a spoiled gradient-echo sequence, without significant artifact. Magnitude, phase, and complex difference images all demonstrated temperature-related signal changes during heating. The findings were better visualized on the phase and complex difference images. Phase difference image analysis revealed an approximately linear relationship between phase change and temperature. Post-treatment thermal lesions measured up to 2.0 cm in size on pathologic specimens and exhibited a zonal pattern on spin-echo MR images.

Animals↗
PubMedDate not supplied

Leigh's disease with clinical manifestations of Cornelia de Lange syndrome.

Leigh's disease was found postmortem in a 5-year-old girl who was diagnosed clinically as Cornelia de Lange syndrome at age 1 year. The child's neurological status began to deteriorate rapidly at age 4.5 years and she died suddenly 6 months later. Postmortem examination of the brain revealed bilateral necrosis of the hypothalamus, subthalamic nuclei, midbrain, pons, and medulla. Previous studies have linked Cornelia de Lange syndrome to hypothalamic lesions. This case demonstrates that Leigh's disease, which also damages the hypothalamus, could present with phenotypic features of Cornelia de Lange syndrome.

Brain↗
PubMedDate not supplied

Cytologic diagnosis of a solitary brain metastasis from papillary carcinoma of the thyroid. A case report.

BACKGROUND: Papillary carcinoma of the thyroid metastasizes to the brain in rare instances. In published series and case reports of metastatic papillary thyroid carcinoma, diagnosis of central nervous system (CNS) metastases has been determined by histologic methods. We present a case of papillary carcinoma metastatic to brain diagnosed by cytologic methods. CASE: A 43-year-old female, initially diagnosed at age 12 with papillary carcinoma of the thyroid metastatic to regional lymph nodes and lung, presented with head aches of increasing frequency and severity. A computed tomography scan confirmed a 1-cm nodule in the right inferior frontal lobe of the brain. For clinical reasons, the patient was followed with serial imaging for five years. At age 48 there was significant progression of the CNS disease, and the patient underwent stereotactic biopsy with drainage of cyst fluid. Cytologic examination of the cyst fluid and immunocytochemical studies confirmed the typical features of papillary thyroid carcinoma, including papillary clusters of cells with finely granular chromatin, micronucleoli, nuclear grooves and an associated psammoma body. CONCLUSION: Neurocytology is a useful technique in the examination of cystic lesions of the brain and may be the sole technique for determination of diagnosis.

Biopsy, Needle↗
PubMedDate not supplied

Bilateral striatal necrosis in hemolytic-uremic syndrome.

A 41-year old resident of a nursing home presented with bloody diarrhea, and subsequently developed hemolytic-uremic syndrome. E. coli serotype O157:H7 was isolated from the stool culture. At autopsy she was found to have bilateral symmetrical striatal necrosis involving mainly the putamen and lateral globus pallidus. The main microscopic findings consisted of coagulative necrosis, endothelial damage and microthrombosis. Scattered microscopic lesions of similar appearances were noted in the parietal cortex, external capsule and fornix. This case is of particular interest because of the rarity of bilateral striatal necrosis in hemolytic-uremic syndrome and the recent experimental data which implicate E. coli endotoxin in the pathogenesis of cerebral lesions in this syndrome.

Adult↗