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Biomedical subjects

D M Ho

Publications and source records attributed to D M Ho.

At least 37 records · Page 2Linked to original sources
PubMed1998

Hemichorea-hemiballism: an explanation for MR signal changes.

PURPOSE: Some cases of hemichorea-hemiballism (HCHB) are associated with a hyperintense putamen on T1-weighted MR images, the cause of which remains unclear. Our purpose was to determine the cause and significance of these MR signal changes. METHODS: We analyzed the clinical and neuroimaging findings in 10 patients with HCHB, focusing on locations of the hyperintense lesions on T1-weighted images, comparing them with those on CT scans, and evaluating their changes after years of follow-up. A biopsy was performed in one patient. RESULTS: Seven patients had hyperglycemia and two had cortical infarcts. HCHB recurred in four patients. A hyperintense putamen preceded the occurrence of HCHB in two patients. T1-weighted MR images revealed hyperintense lesions limited to the ventral striatum in six patients. Hyperintense lesions extended to the level of the midbrain in one patient and persisted for as long as 6 years in another patient. T2-weighted MR images revealed slit-shaped cystic lesions in the lateral part of the putamina 2 to 6 years after the onset of symptoms in two patients. A biopsy specimen from the hyperintense putamen in one patient revealed a fragment of gliotic brain tissue with abundant gemistocytes. Proton MR spectroscopy of the specimen showed an increase in lactic acid, acetate, and lipids, and a decrease in N-acetylaspartate and creatine, suggesting the presence of pronounced energy depletion and neuronal dysfunction. CONCLUSION: Gemistocytes are sufficient to explain the shortening of T1 relaxation time. Our investigation suggests that neurons in the ventral striatum and striatonigral pathway may play a critical role in generating ballism.

Adolescent↗
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↗
PubMed1997

The clinicopathological characteristics of gonadotroph cell adenoma: a study of 118 cases.

Gonadotroph cell adenoma was the most common pituitary adenoma, constituting 35% of the pituitary adenomas in our series of 339 patients with surgically removed pituitary adenomas from June 1987 to December 1995. The average age of these patients was 53 years, with a male predominance (1.5:1). The most common neurological symptoms were visual symptoms and headache. Amenorrhea and galactorrhea were recorded in 41% and 14%, respectively, of the female patients of reproductive age. Oncocytic change of varying degrees was seen in 69% of the tumors, and the average age of these patients (56 years) was older than those who had no such change (47 years) (P < .005). Five types of gonadotroph cell adenomas were recognized; they were tumors that contained (1) betaFSH, betaLH, and alphaSU, (2) betaFSH and betaLH, (3) betaFSH and alphaSU, (4) betaFSH, and (5) alphaSU. The immunostaining of betaFSH-containing cells was usually diffuse, whereas staining of betaLH- or alphaSU-containing cells was usually focal. Double immunostaining showed the immunoreactive cells containing one or any combination of the gonadotropin subunits. Increases in serum gonadotropin levels were only seen in 35% of the patients with gonadotroph cell adenoma. There was no correlation between serum hormonal levels and immunostaining results. Of the 33 recurrent cases, significant decrease or total absence of immunoreactivity of one or more hormone subunits in subsequent biopsy specimens were seen in three cases.

Adenoma↗
PubMed1996

Chloro(ethylenediamine)(6-phenylimidazo-[2,1-b]thiazole-N7)platinum(II) nitrate.

Platination of 6-phenylimidazo[2,1-b]thiazole at the imidazole N atom to give chloro(ethylenediamine)(6-phenylimidazo[2,1-b] thiazole)platinum(II) nitrate, [PtCl-(C2H8N2)(C11H8N2S)]NO3, is accompanied by a rotation of 49.3 (8) degrees of the phenyl ring and a loss of extended conjugation in the normally planar 6-phenylimidazo[2,1-b]thiazole molecule.

Crystallography, X-Ray↗
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

Production of a monoclonal antibody to an antigen present on both trophoblasts and leukocytes.

In the present study, we report the establishment of a monoclonal antibody (Mab) designated F10 that recognized an antigen commonly shared by human trophoblasts and leucocytes. F10 MAb was obtained using cell membrane components from a trophoblast cell line HT as immunogen. Based on immunochemical studies, the F10 reactive antigen (F10-Ag) could be located on both villous and nonvillous trophoblasts from early and term placental tissues and on all trophoblastic cell lines. In addition, flow cytometry revealed that most ( > 95%) peripheral blood lymphocytes, monocytes, as well as polymorphonuclear leukocytes (PMN) were positively stained with F10 MAb. Immunoblotting with F10 MAb identified two protein bands with apparent molecular mass of 62 and 56 kDa. Furthermore, the antigens were glycoproteins and were glycosylated via the O-linkage. Scatchard plot analyses of the binding data between 125I-labeled MAb F10 IgG and HT cells revealed a single class of F10 binding sites with an apparent dissociation constant (Kd) of 10.54 +/- 2.03 pM and maximum binding-site (Bmax) value of 2.1 +/- 0.11 x 10(6) sites per cell. We suggest that F10 may be useful for the identification of a novel epitope that is commonly shared by all trophoblasts and leukocytes and such an epitope may be potentially active in maternal-fetal interactions.

Antibodies, Monoclonal↗
PubMed1994

Temporal lobectomy in adults with intractable epilepsy.

We report on 30 adult patients with intractable complex partial seizure (CPS) of the temporal lobe origin who received anterior temporal lobectomy. The average follow-up period was 41 months. The age of onset was younger and the duration of epilepsy was longer in the non-mass lesion group than in the mass lesion group. Postoperatively, 21 patients (70%) were seizure-free, four patients (13%) had only rare seizures (less than three attacks per year), three patients (10%) achieved a remarkable reduction (more than 50%) of seizure frequency, and two patients (7%) showed no worthwhile improvement. Based on our experience, anterior temporal lobectomy is an effective and safe procedure for adult patients with intractable CPS. For diagnosis, magnetic resonance imaging (MRI) yielded a higher sensitivity rate than computed tomography (CT), especially in the group without mass lesions. Positron emission tomography using 18F-fluorodeoxyglucose (FDG-PET) was superior to single photon emission computed tomography (SPECT) which had a relatively high false localization rate. With high resolution MRI and FDG-PET, localization of the epileptogenic zone was more accurate. A preresection electrocorticogram (ECoG) was used to confirm the epileptogenic focus during the operation. The residual spikes on the postresection ECoG did not necessarily predict a poor seizure control outcome after anterior temporal lobectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Histopathological changes in Kock pouch.

To investigate whether tumour recurrence or histological changes occur in the Kock pouch, periodic endoscopy with biopsy of the pouch was performed in 15 patients 6 to 66 months after radical cystectomy and urinary diversion for invasive bladder cancer. Endoscopy was undertaken 1 to 4 times in each patient (a total of 37 times in all patients). During endoscopy, random biopsies were taken from the pouch wall, and from the afferent and the efferent nipples. The histological changes were graded as: (1) villous atrophy (grade 0 to 3, 0: nearly normal; 1: shortening, villi/crypt of Lieberkuhn [length] between 1.5 and 4.0; 2: moderate flattening, villi/crypt < 1.5; and 3: almost complete disappearance of villi); (2) fibrosis; and (3) chronic inflammation (grade 0 to 3, based on the amount of fibrous tissue and inflammatory cell infiltration in the lamina propria, respectively). There was no dysplasia or malignant tumour in the Kock pouch in any of the 15 patients. The histology of the ileum changed in terms of villous atrophy, fibrosis and chronic inflammation in the lamina propria and thickening of the muscularis mucosa. The same grade of villous atrophy of the pouch wall, the afferent and the efferent nipples was only found in 3 patients. More fibrosis and less chronic inflammation in the lamina propria were found at the efferent nipple than at the afferent nipple or pouch wall in 8 patients and 5 patients, respectively. Thickening of the muscularis mucosa was found in 13 of 15 patients (86.7%). In conclusion, there was no dysplasia or recurrent tumour in the Kock pouch in patients who were followed for up to 66 months. Various grades of histological changes of the ileum in terms of villous atrophy, fibrosis and chronic inflammation of the lamina propria, and thickening of the muscularis mucosa were found in the pouch wall, and in the afferent and efferent nipples. More fibrosis and less chronic inflammation were commonly observed at the efferent nipple than at the afferent nipple or pouch wall. The degree of histological changes varied even among patients followed over the same period after operation. The time to progression of villous atrophy also varied. The histological changes in some patients were dissimilar even at the same site of the Kock pouch.

Aged↗
PubMed1992

Primary intracranial germ cell tumor. Pathologic study of 51 patients.

Fifty-one primary intracranial germ cell tumors (GCT), including germinoma, teratoma, endodermal sinus tumor, choriocarcinoma and mixed GCT, were studied. The incidence of GCT in the surgically removed intracranial neoplasms was 11.1% for pediatric patients and 0.6% for adult patients. The age/sex of the patients and the location of the tumors were analyzed. Morphologic findings of these tumors were identical to that of their gonadal counterparts. Immunohistochemical studies showed that alpha-fetoprotein (alpha-AFP), human chorionic gonadotropin (HCG), and placental alkaline phosphatase (PLAP) were helpful, whereas carcinoembryonic antigen (CEA) and cytokeratin (CKER) were of little help in determining the diagnosis. Serum tumor markers, alpha-AFP and HCG, were helpful in recognizing GCT producing them. However, they could not be used for specific diagnosis because different tumors could have similar serum levels. Histopathologic study was handicapped by the small size of most specimens (which usually could not include all of the components if the tumor was a mixed GCT), but it was the only means for specific diagnosis.

Adolescent↗
PubMed1992

Prolactin-containing pituitary adenomas. Their characteristics and comparative study with non-prolactin adenomas.

Immunohistochemical study of 130 pituitary adenomas shows that 31% are prolactin-containing adenomas, two-thirds of which are monohormonal adenomas, i.e. prolactin cell adenoma, and one-third are multihormonal adenomas, i.e. mixed growth hormone cell-prolactin cell adenoma and plurihormonal adenoma with prolactin. Clinical symptoms including amenorrhea and galactorrhea are not useful in distinguishing prolactin from non-prolactin adenomas. Serum prolactin concentration of 80 ng/ml is a good cut-off point to distinguish prolactin cell adenoma from non-prolactin adenoma but can not separate many of the multihormonal adenomas from non-prolactin adenomas. Calcification is not only more commonly seen but also more prominent in prolactin-containing adenomas. Spheroid amyloid is present in one prolactin cell adenoma. Immunohistochemistry is specific and reliable in identifying prolactin-containing adenomas. All prolactin cell adenomas and 2/13 multihormonal adenomas show paranuclear staining of prolactin in almost every adenoma cell. The remaining (11/13) multihormonal adenomas show less prolactin cells and diffuse cytoplasmic staining of prolactin. The prolactin staining pattern in the latter group is unique and appears to be indicative of the presence of other hormone(s).

Adenoma↗
PubMed1992

Production and characterisation of a monoclonal antibody (Cx-99) against cervical carcinoma.

An IgG1 monoclonal antibody (MAb Cx-99) has been established which recognises a surface antigen on epithelial cells, but not on fibroblastic or hematopoietic cells. Immunohistochemical studies showed that this antigen was present in all 37 squamous cell carcinomas (SCC) including 33 cervical SCC, and 30 of the 32 adenocarcinomas examined; most of the 33 cervical SCC were stained extensively. It was also detected in the culture medium of cervical cancer cell lines. In the normal cervix, this antigen was restricted to the undifferentiated basal cells. This observation suggests that the widespread expression of the antigen was triggered by oncogenesis. The MAb Cx-99 recognised an epitope on an asialyted glycoprotein which has an apparent molecular weight of 37 kilodaltons (kD) (and 2 minor proteins at 18 and 27 kD) and an isoelectric point (pI) of 5.3. It may have potential for studies on differentiation and oncogenesis and for diagnostic applications.

Animals↗
PubMed1992

[Successful treatment of congenital anaplastic astrocytoma by combining vinblastine, cisplatin and etoposide: a case report].

Congenital brain tumor is a rare disease in the neonatal period. According to the literatures, they comprise only about 1% of childhood brain tumors. Among the congenital brain tumors, 10%-25% are astrocytomas. Anaplastic astrocytoma is one of the malignant glioma. The prognosis is usually not good in the childhood or adult stage. We report one case of congenital anaplastic astrocytoma who received combination chemotherapy, including vinblastine, cisplatin and etoposide following subtotal resection of tumor. After chemotherapy, he got a favorable outcome. And now, he is still no evidence of tumor recurrence for two years.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Choroid plexus tumors in childhood. Histopathologic study and clinico-pathological correlation.

Choroid plexus tumors are rare and account for only 2.3% (8/352) of primary childhood intracranial neoplasms in our series. Most of our patients were under 2 years of age. The tumors had a predilection for the lateral ventricle. Calcification was found in half of these tumors, and ossification was seen in 1 case. Histological features of malignancy including invasion, loss of differentiation, and severe nuclear pleomorphism pointed to a poor prognosis. Such features were found in 2 cases. Neither a large number of mitoses nor necrosis was a constant feature in cases of malignancy. Transthyretin, a marker for choroid plexus tumors, was positive in all cases. However, negative S-100 or positive carcinoembryonic antigen was not necessarily associated with a more aggressive histological pattern. All the papillomas could be totally resected without recurrence, and all the patients with carcinoma died within a few months.

Adolescent↗
PubMed1991

[Acrocallosal syndrome--an autopsy case report and literature review].

This is an autopsy report of a female neonate with acrocallosal syndrome, which shows developmental retardation, callosal dysgenesis and preaxial hemimelia of the upper limbs. Either dysgenesis or corpus callosum or congenital absence of radius is rare; their combination are even rarer and only eleven cases of acrocallosal syndrome have been reported in the English literature. Our case appears to be the first report in Taiwan. The family history and pregnant course were unremarkable except that her mother had taken Chinese herb medicine for common cold in the 4th pregnant month. Prenatal obstetric sonography showed "ventriculomegaly" at the 31st week. We reviewed the literature and discussed the incidence, embryology, pathogenesis, symptoms as well as etiology concerning this rare syndrome.

Abnormalities, Multiple↗
PubMed1990

Congenital cerebral primitive neuroectodermal tumor with astrocytic differentiation and extracranial metastases.

A cerebral primitive neuroectodermal tumor with astrocytic differentiation and extracranial metastases in a 28-day-old infant is reported. The infant presented with a progressively enlarged head, cutaneous lesions in the neck, and enlarged cervical lymph nodes. A computed tomography brain scan demonstrated a giant thalamic tumor with subarachnoid dissemination and hydrocephalus. Biopsy material from the cervical lesions showed a picture of glioma with anaplastic astrocytes. The patient received a ventriculoperitoneal shunt operation and palliative chemotherapy, but died at 3 months of age. Autopsy was performed. Histological studies, which included immunohistochemical stains of the thalamic tumor, showed small, round, primitive, neoplastic cells with focal astrocytic differentiation.

Astrocytes↗
PubMed1990

Silent corticotropic adenoma of pituitary gland--a case report.

A 79-year-old man complained progressive visual impairment and Diplopia for 2 weeks. A big pituitary tumor was found and partially removed by the surgeon eventually. The tumor cells were chromophobic with H&E stain and exhibited focal positive staining with PAS. Immunoperoxidase method demonstrated moderate positivity for adrenocorticotrophic hormone (ACTH), while staining for growth hormone (G.H) and prolactin were negative. The patient was eucorticoid clinically and biochemically. Since silent corticotropic adenoma of the human pituitary gland is rarely encountered clinically, a review of the literature is included in this article.

Adenoma, Chromophobe↗
PubMed1990

Coexisting hyperthyroidism and hyperparathyroidism: two cases report.

To examine the biochemical changes in coexisting hyperthyroidism and hyperparathyroidism, we have studied two female cases in our medical center. Both patients received biochemistry study, thyroid function test, thyroid autoantibody determination, parathyroid function tests and thyroid scan. They all had increased thyroid function. The concentration of parathyroid hormone was found to elevate in both cases. After thyroid function turned normal, hypercalcemia was still present. Both patients underwent neck operation. Parathyroid adenoma was found in both cases. The pictures of thyroid pathology showed diffuse hyperplasia in one case and lymphocytic thyroiditis in the other case.

Adenoma↗