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Biomedical subjects

D E Powell

Publications and source records attributed to D E Powell.

At least 55 records · Page 3Linked to original sources
PubMed1988

Small cell carcinoma of the uterine cervix.

From 1962 to 1985, 2201 patients with invasive cervical cancer were staged, evaluated, and treated at the University of Kentucky Medical Center. After a thorough evaluation, 25 cases (1.1%) fulfilled the histologic criteria for small cell cancer defined by Reagan and coworkers. These patients were computer-matched for age, disease stage, and lesion size to 25 patients with large cell nonkeratinizing cancer and 25 patients with keratinizing squamous cell cancer. Morphometric analyses of nuclear size and maximum nuclear diameter were performed on all cases without knowledge of cell type. Small cell cancers were characterized by a nuclear area of 160 mu 2 or less and a maximum nuclear diameter of 16.2 mu, which was significantly lower than that for large cell tumors. Thirty-three percent of the small cell carcinomas stained positively for the neuroendocrine markers (neuron-specific enolase [NSE] and chromogranin [CGR]), whereas the remainder contained only epithelial markers such as cytokeratin (CYK) and epithelial membrane antigen (EMA). Small cell cancers were associated with a high frequency of lymph-vascular space invasion and a diminished lymphoplasmacytic response. Patients with small cell cancer had a significantly higher recurrence rate, particularly to extrapelvic sites, than the matched patients with large cell cancers, and their survival was lower. Clinical trials to determine the efficacy of adjuvant chemotherapy in the treatment of small cell cervical cancer are needed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

Ovarian dysgerminoma: report of seven cases and review of the literature.

Seven cases of ovarian dysgerminoma are presented and the recent literature reviewed. The majority of the cases reviewed had tumor confined to one ovary at the time of diagnosis, and nearly 50% occurred in women less than 20 years of age. The 5-year survival rate was 91% for 211 patients with stage I disease and 65% for 60 patients with stage II to IV dysgerminoma. The addition of contralateral adnexectomy, abdominal hysterectomy, and radiation therapy was not beneficial when disease was confined to one ovary. The survival of patients with advanced disease treated with chemotherapy was comparable with that of patients who received radiation. Analysis of the present data suggests that the use of unilateral oophorectomy should be limited to those patients with disease confined to one ovary and no histologic evidence of lymph node metastasis. Abdominal hysterectomy, bilateral adnexectomy, and adjuvant radiation is currently the treatment of choice for patients with more advanced dysgerminoma.

Adolescent↗
PubMed1988

Prognostic factors in early vulvar cancer.

Prognostic parameters were evaluated in 22 patients with small (less than or equal to 2 cm) superficially invasive (less than 5 mm) squamous cell carcinoma of the vulva. Primary surgery included radical vulvectomy with bilateral superficial and deep inguinal lymph node dissection in 11 patients, and wide local excision with ipsilateral superficial inguinal lymph node dissection in 11 patients. Of the 22 patients studied, only 2 (9%) had lymph node metastases. Both patients had a single positive ipsilateral superficial inguinal node. Perineural invasion was strongly associated with lymph node metastases (P less than 0.01). In this group of patients, grade, depth of invasion, lymph-vascular space invasion, and lymphoplasmacytic infiltration were not predictive of lymph node metastases (P greater than 0.05). Two patients initially treated with wide local excision and ipsilateral superficial inguinal lymph node dissection developed recurrent vulvar neoplasia on the contralateral vulva, and both were successfully retreated by wide local excision. All patients are presently alive and well with no evidence of disease. None of the histomorphologic parameters studied were predictive of tumor recurrence. These data suggest that wide local excision with ipsilateral superficial inguinal lymphadenectomy is effective in the treatment of patients with small, superficially invasive carcinomas of the vulva.

Adult↗
PubMed1988

Magnetic resonance imaging of the human female breast. Current status and pathologic correlations.

Over the past decade, research in MR of the female breast has focused on in vitro studies of excised breast tissue samples or mastectomy specimens and on in vivo clinical imaging of patients, usually with biopsy correlation. The results of in vitro measurement of T1 and T2 times of excised benign and malignant breast tissue do not conclusively demonstrate a clear separation based on these values alone. In particular, benign tumors (fibroadenomas) cannot be distinguished from carcinomas and there is considerable overlap in values for cancer and fibrocystic disease. MR images produced from mastectomy specimens allow detailed correlation with mammographic and histologic findings but are incompletely applicable to in vivo images because of numerous factors including tissue changes associated with disruption of blood supply. In vivo studies have shown that benign tumors (fibroadenomas), fibrocystic changes, and cancers can be imaged successfully by MR. To date the best images show a resolution of about 2 mm. Small cancers and cysts have been imaged successfully but proliferative patterns of fibrocystic disease cannot be differentiated at this time. Carcinomas occurring in dense fibroglandular breasts which are a problem to image mammographically have not been successfully imaged by MR in vivo and in only one instance in vitro in a mastectomy specimen. Since MR cannot image microcalcifications, it does not appear likely to replace mammography as the imaging modality of choice at the present time. Newer magnets of increased strength, specialized surface coils specifically for breast imaging, and the use of contrast enhancing agents all may increase the usefulness of MR as an imaging modality for the detection of breast disease. In particular, increased resolution and contrast enhancing agents which may aid in tissue differentiation should be studied for their ability to detect carcinomas in dense fibroglandular breast tissue and to identify lesions of carcinoma in situ and proliferative patterns of fibrocystic disease. The need for careful collaborative studies between radiologists and pathologists will be essential for the success of these research efforts.

Adenofibroma↗
PubMed1987

Treatment of stage IIIB cervical cancer with Californium-252 fast-neutron brachytherapy and external photon therapy.

From January 1977 to July 1984, 32 patients with Stage IIIB cervical cancer were treated at the University of Kentucky Medical Center by a combination of outpatient neutron brachytherapy and external pelvic radiation. These patients received 4500 to 5000 rad external photon therapy and two or three outpatient Californium-252 (252Cf) implants, plus sidewall boost irradiation. Treatment results were compared retrospectively to those obtained in a historical control group of patients with Stage IIIB cervical cancer treated with external radiation and conventional photon brachytherapy from 1972 to 1976. Local or regional tumor recurrence developed in 53% of patients treated with neutron therapy and an additional 9% experienced distant metastases. Thirty-eight percent of patients remain free of disease 12 to 96 months (mean, 51 months) after therapy. The 2-year and 5-year survival rates of patients treated with neutron therapy were 53% and 36%, which were not significantly different than those obtained with photon brachytherapy (2-year survival, 61%; 5-year survival, 34%). Complications of neutron therapy were minimal and included proctitis (19%) and vaginal stenosis (9%). There were no cases of enteric fistulae. Outpatient neutron brachytherapy was cost effective and was well tolerated by patients.

Adult↗
PubMed1987

Endometrial cancer following radiation therapy for cervical cancer.

The clinical and histologic features of eight cases of carcinoma of the endometrium which developed following radiation therapy for squamous cell carcinoma of the cervix are described. No patient had a well-differentiated tumor and significant myometrial invasion was present in all cases. Three of the eight tumors were papillary serous adenocarcinoma. Five of the eight patients developed recurrent tumor and died of their disease. The risk of endometrial cancer in patients previously radiated for cervical cancer is evaluated.

Adenocarcinoma, Papillary↗
PubMed1987

Fibroadenomas: histopathologic and MR imaging features.

Twelve fibroadenomas were studied in vivo using magnetic resonance (MR) imaging with a cylindrical surface coil and at 0.15 T. On T1-weighted images, most fibroadenomas had an intensity similar to that of normal fibroglandular tissue; areas of inhomogeneity were seen in six. On five of the T2-weighted images, the fibroadenomas gave a signal equal to or slightly greater than that of normal fibroglandular tissue; five showed a marked increase in intensity, and two gave a low signal intensity. Four fibroadenomas were inhomogeneous on both T1- and T2-weighted images, and two additional lesions became inhomogeneous on T2-weighted images. No consistent correlations were found between MR appearances and histopathologic findings in the fibroadenomas. It is concluded that the appearance of fibroadenomas on MR images is sufficiently variable that it would be difficult to differentiate benign from malignant circumscribed tumors on the basis of MR imaging alone.

Adenofibroma↗
PubMed1987

Multiple endocrine neoplasia type IIb: a description of several patients and review of the literature.

Our experience exemplifies the varied clinical presentations of patients with MEN IIb. This syndrome may be familial or sporadic, and clinical stigmata may be identifiable in infancy, particularly the characteristic facies and the appearance of ganglioneuromas. First-degree relatives of affected propositi and individuals with other stigmata of the syndrome should be screened carefully and repeatedly for both medullary thyroid carcinoma and pheochromocytoma. The availability of sensitive screening tests may permit detection of C-cell hyperplasia of the thyroid and adrenal medullary hyperplasia before the development of malignancy or hemodynamic consequences of pheochromocytoma. Early detection of these thyroid and adrenal disorders will permit early surgical intervention.

Adolescent↗
PubMed1986

Phase II clinical trial using californium 252 fast neutron brachytherapy, external pelvic radiation, and extrafascial hysterectomy in the treatment of bulky, barrel-shaped stage IB cervical cancer.

From June 1977 to June 1983, 32 patients with bulky (greater than 4 cm diameter), barrel-shaped Stage IB cervical cancer were treated at the University of Kentucky Medical Center by a combination of outpatient neutron brachytherapy using californium 252 (252Cf) and external pelvic radiation followed by extrafascial hysterectomy. Nineteen patients had cervical tumors 4 to 6 cm in diameter, and 13 patients had lesions in excess of 6 cm in diameter. A dose of 4500 rad external photon therapy was given from a linear accelerator, and one or two 6-hour 252Cf implants were given during or immediately after external radiation. Extrafascial hysterectomy with bilateral salpingo-oophorectomy was performed 6 weeks after completion of radiation therapy. Complications during and after radiation were minimal and included vaginal stenosis (three) and proctitis (two). Tumor clearance in the hysterectomy specimen was complete in 23 patients (72%) and residual cervical tumor was present in 9 patients (28%). Two patients developed tumor recurrence and died of disease 15 and 27 months after therapy, respectively. Thirty patients remain free of disease 26 to 96 months (median, 52 months) after treatment, and none have been lost to follow-up. The actuarial survival of these patients is 97% at 2 years and 94% at 5 years. Intracavitary neutron therapy is well tolerated and is effective when combined with external radiation and hysterectomy in the treatment of bulky, barrel-shaped Stage IB cervical cancer.

Adult↗
PubMed1985

Combined radiation therapy and extra-fascial hysterectomy in the treatment of stage IB barrel-shaped cervical cancer.

Seventy-five patients with bulky barrel-shaped Stage IB cervical cancers, treated at the University of Kentucky from 1965 to 1981, were the subjects of this investigation. Thirty-two of these patients were treated with radiation therapy alone and 43 were treated with radiation followed by extra-fascial hysterectomy. There were no significant differences in age, gravidity, or tumor cell type between the two treatment groups. Patients were seen at regular intervals from 2 to 11 years after treatment and none were lost to follow-up. Recurrent cancer was noted in 47% of patients treated by radiation alone as compared to 16% of those treated with combined therapy (P less than 0.01). The incidence of pelvic recurrence was reduced from 19% to 2% and extrapelvic recurrence from 16% to 7% in patients treated by combination therapy. No rectal or urinary tract fistulae were noted after extra-fascial hysterectomy. The findings of this study suggest that the use of extra-fascial hysterectomy following radiation therapy in patients with bulky Stage IB cervical cancer causes a significant reduction in tumor recurrence without producing an increase in treatment-related complications.

Adult↗
PubMed1985

The prognostic significance of lymph-vascular space invasion in stage I endometrial cancer.

Surgical specimens from 111 patients with Stage I endometrial cancer were reviewed for the presence of lymph-vascular space invasion by tumor cells. Lymph-vascular space invasion was noted in 16 cases, and occurred most frequently in poorly differentiated tumors with deep myometrial penetration. Tumor recurrence developed in 44% of patients whose tumors demonstrated lymph-vascular space invasion as opposed to only 2% of patients without this finding (p less than 0.001). Of seven patients with lymph-vascular space invasion who experienced tumor recurrence, five developed extra-pelvic metastases. Discriminant function analysis of these data revealed a statistically significant correlation between lymph-vascular space invasion and tumor recurrence, independent of histologic differentiation of myometrial penetration. These findings suggest that lymph-vascular space invasion by tumor cells is an important prognostic variable in Stage I endometrial cancer which should be considered in treatment planning.

Adenocarcinoma↗
PubMed1985

Alterations in metaphase durations in cells derived from human tumours.

With the use of time-lapse cinemicrography, we previously found that metaphase durations were significantly prolonged in SV40-transformed human fibroblasts when compared to untransformed controls. This was consistent with some earlier reports and suggested that prolonged metaphases could account for high metaphase/prophase ratios and possibly, in part, for increased mitotic indices seen in advanced tumours. However, there are inconsistencies in the literature and no comparable data available from malignant carcinomas. Presented in this paper are data from two cervical dysplasias, two cases of carcinoma in situ, nine malignant carcinomas and several other types of human cells. The results show that mean metaphase durations were prolonged in cells derived from most of the carcinomas but not from the other cell types. On the other hand, cytokinesis appears to progress more rapidly than normal in most of the tumour-derived cells. These and other findings indicate that the changes are a result of some metabolic alteration common to many but not all tumour cells. For reasons presented, we suggest as a working hypothesis that the alterations may be due to changes in calcium regulation, possibly resulting from alterations in mitochondrial metabolism.

Cell Line↗
PubMed1985

Prototype coil for magnetic resonance imaging of the female breast. Work in progress.

Magnetic resonance imaging (MRI) of the breast was performed in 35 women using a prototype breast coil at 0.15 T. The distribution of fibroglandular and fatty tissues was demonstrated sufficiently well to permit correlation with the mammographic patterns of Wolfe, and it was possible to identify 1-cm cysts. The signal intensity of the cysts varied from low to high as repetition time (TR) and echo time (TE) using the spin echo technique (TR/TE) were prolonged from 250/30 to 1,000/120. In two women, fibroadenomas were seen as low-intensity, smoothly marginated lesions surrounded by fat. A range of in vivo observed T1 values is summarized for normal and pathologic tissues. It is concluded that MRI of the female breast, currently in the developmental phase, is feasible and further evaluation is indicated.

Adipose Tissue↗
PubMed1985

Suprasellar germ cell tumor with extracranial metastases.

A case of metastasizing suprasellar germ cell tumor is described. Serum tumor markers were measured and the immunochemistry of the tumor was studied. The rarity of extracranial metastasis from suprasellar germinomas is noted, and the relevance to mixed tumors is discussed. The difficulties associated with small biopsies and the importance of tumor marker studies in all cases of an intracranial germ cell tumor are emphasized by the case study.

Adolescent↗
PubMed1984

Effect of estradiol and progesterone on human chorionic gonadotropin secretion in vitro.

Many of the substances known to control the secretion of pituitary gonadotropins also modulate the secretion of human chorionic gonadotropin (hCG) by the placenta. In order to study the effect of estrogens and progestins on hCG secretion, term placental explants were cultured in culture media for 144 hours. During the culture period, hCG secretion increased after 48 hours, and a fortyfold increase was observed after 144 hours (p less than 0.001). Compared to concentrations of hCG in control cultures, secretion of hCG was markedly suppressed in the presence of progesterone 2.25 X 10(-5)M (p less than 0.001), a concentration similar to that found in term placental tissue (1.7 +/- 0.2 micrograms/gm of tissue). Suppression of hCG by progesterone occurred in a dose-response manner (r = -0.9100, p less than 0.01). Estradiol, an important steroid modulator of pituitary gonadotropins, did not significantly suppress the secretion of hCG, except in pharmacologic concentrations (10(-4)M), and physiologic concentrations of estradiol had no effect on the suppression of hCG by progesterone. These results suggest that the mechanism by which progesterone suppresses the secretion of hCG differs from the manner in which steroids modulate the secretion of pituitary gonadotropins.

Cesarean Section↗