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Biomedical subjects

D M Ho

Publications and source records attributed to D M Ho.

At least 55 records · Page 3Linked to original sources
PubMed1989

The effect of sexual activity on androgen metabolism, androgen-receptor translocation, and glandular weight of ventral prostates of rats.

The present study was conducted to determine whether sexual activity exerts an effect on the action of androgen in the rat prostate. Eight-week-old Sprague-Dawley male rats were divided into two groups. Rats were grouped with female rats (sexualactive), or male (sexual-inactive) rats, and sacrificed 6 months later, The ventral prostates were dissected, homogenized and processed into cytosol and nuclei fractions. Testosterone and dihydrotestosterone were quantified by radioimmunoassay, and androgen receptor was determined by 'exchange assay' with radioactive methyltrienolone incubated for 18 h at 15 degrees C. The main result were: 1) The steroid levels of testosterone and dihydrotestosterone in plasma and in the cytosolic fraction of prostate showed no significant difference between the two group of rats. 2) The prostatic nuclear dihydrotestosterone concentration of the sexual-active group (4.3 +/- 0.83 pmol/mg DNA, N = 6) was significantly higher (P less than 0.01) than that of the sexual-inactive group (1.68 +/- 0.43, N = 6). 3) The androgen receptor was significantly higher (P less than 0.05) in nuclear extract (0.64 +/- 0.11 pmol/mg DNA, N = 6) and significantly lower (P less than 0.01) in cytosol (53.4 +/- 5.7 fmol/mg protein, N = 6) of the sexual-active group than those of the sexual inactive group (0.42 +/- 0.13, N = 6 and 74.6 +/- 11.8, N = 6, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Clear cell sarcoma of tendons and aponeuroses (malignant melanoma of soft parts): report of 2 cases.

Clear cell sarcoma of tendons and aponeuroses (CCSTA, malignant melanoma of soft parts), first described by Enzinger in 1965, is a rare and slow-growing soft tissue tumor mainly affecting the extremities of young adults. The tumor is believed to be a tumor of melanocyte, although its histogenesis is not definitely established. Here we report 2 cases of CCSTA with typical clinical and pathological features. A tumor grew from the right ankle of a 32-year-old man (case 1) and from the left foot of an 18-year-old woman (case 2). The tumors were deep seated and intimately bound to tendons or aponeuroses without involvement of the overlying skin. Grossly, they were greyish white, variegated with brown or black patches. Histologically, the tumor cells were arranged in nests or fascicles and composed of fusiform or polygonal cells with clear cytoplasm. Ultrastructurally, they consisted of closely apposed cells with intracytoplasmic melanosomes. Case 1 was found to have distant metastases within 6 months and died 1 year later. Case 2 received postoperative radiotherapy and was free of recurrence or metastasis 14 months after operation. The treatment of CCSTA should include radical excision, radiotherapy, and chemotherapy. The prognosis is poor.

Adolescent↗
PubMed1989

Medullomyoblastoma: a case report.

Medullomyoblastoma is a rare childhood tumor of the central nervous system and there have been only seventeen cases reported in the English literature. A case of medullomyoblastoma arising from the cerebellar vermis was reported. Postmortem examination revealed diffuse leptomeningeal dissemination and supratentorial metastasis. In addition to classical histologic examination, the immunohistochemical and ultrastructural features were studied. Besides skeletal muscle differentiation, neither neuronal nor astrocytic differentiation were identified. The myoblastic element was confirmed by the demonstration of thick and thin myofilaments and Z bands on electron microscopy and by positive immunostaining for myoglobin.

Cerebellar Neoplasms↗
PubMed1989

Leiomyosarcoma of uterus: a review of 14 cases.

A detailed clinicopathologic study of 14 patients with leiomyosarcoms of the uterus was made. Twelve of 14 patients were followed up for 2 or more years. The median age was 49, the youngest patient was 20, and the oldest was 68. The predominant symptoms were abnormal vaginal bleeding and abdominal pain. The preoperative dilation and curettage established the correct diagnosis was 2 of 6 patients (33%). The predominant method of treatment was total abdominal hysterectomy (TAH). Five patients had adjuvant chemotherapy, 4 had adjuvant radiotherapy, 2 patients had chemotherapy and radiotherapy for adjuvant treatment, and one had adjuvant hormonal therapy. The overall cumulative probability of survival rate at 5 years was 29.6%. The mitotic count, margin type, tumor size, and the presence of necrosis did not affect the prognosis. Favorable prognostic features are low pleomorphism, lower staging, and aggressive management.

Adult↗
PubMed1987

Oligodendroglioma occurring after radiation therapy for pituitary adenoma.

A 38 year old male dentist developed an oligodendroglioma of the left medial temporal lobe and parasellar region 12 years after radiotherapy with 6600 rads of acromegaly. The 30 cases of radiation-induced gliomas reported in the English literature are reviewed and analysed. The criteria for defining radiation-induced tumours of the central nervous system are proposed as follows: the tumour has a long quiescent "latency period", a location in the previously irradiated field, a verified histological difference from a primary condition, and does not arise from a primary condition associated with a genetic syndrome such as neurofibromatosis or tuberous sclerosis. The reported case fulfilled these criteria but appears to be the only reported radiation-induced oligodendroglioma.

Adenoma↗