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Biomedical subjects

M W Lee

Publications and source records attributed to M W Lee.

At least 91 records · Page 5Linked to original sources
PubMed1993

Fine-needle aspiration cytologic study of myofibroblastoma of the breast. Immunohistochemical and ultrastructural findings.

Myofibroblastoma of the breast is a recently recognized benign stromal tumor arising from the breast mesenchyma. Myofibroblastomas are grossly circumscribed, unencapsulated tumors that are most commonly found in males. Histologically, myofibroblastomas comprise predominantly bipolar spindle cells arranged either haphazardly or in fascicles that traverse a collagenous background. Their ultrastructural and immunohistochemical profiles are consistent with myofibroblastic differentiation. Myofibroblastoma of the breast was discovered in a 64-year-old man. For the first time the fine-needle aspiration findings are reported, as are the histologic, immunohistochemical, and ultrastructural findings.

Actins↗
PubMed1993

Tumours of the brain and presence of antibodies to Toxoplasma gondii.

The possible association between prior infection with the protozoan Toxoplasma gondii and development of brain tumours was investigated as part of two Australian population-based case-control studies of adult brain tumours. One study, based in Adelaide, South Australia, collected blood from 73 subjects with glioma, 53 subjects with meningioma and 348 controls. The other study, based in Melbourne, Victoria, collected blood from 44 subjects with glioma and 67 controls. All tumours had been verified histologically. IgG antibodies to T. gondii were measured using Enzyme Linked Immunosorbent Assay (ELISA) techniques. In both the centre-specific and combined analyses, there was no difference between subjects with glioma and controls in the prevalence of antibody test-positivity (35% test-positive in glioma versus 33% in controls, age-, sex- and centre-adjusted odds ratio (OR) = 1.00, 95% confidence interval (CI): 0.64-1.56). In the Adelaide study, there was a statistically significant increased risk of meningioma associated with antibody test-positivity (47% test-positive in meningioma versus 31% in controls, P = 0.02, adjusted OR = 2.09, 95% CI: 1.14-3.83). Our results do not support the hypothesis that antibody positivity to T. gondii is a risk factor for glioma, but suggest that it might be associated with meningioma.

Adult↗
PubMed1993

Metabolism of a long-chain diacylglycerol by permeabilized A10 smooth muscle cells.

The regulatory effects of diacylglycerol (DAG) second messengers will be terminated by metabolism. A long-chain DAG, 1-palmitoyl-2-[1-14C]oleoyl-sn-glycerol (2-[14C]POG), was metabolized by cultured A10 smooth muscle cells after permeabilization by preincubation with 340 U/ml alpha-toxin from Staphylococcus aureus. In contrast to results with the cell-permeable DAG analogue, dioctanoyl-glycerol ([3H]diC8), no appreciable 2-[14C]POG degradation could be detected in control A10 cells not treated with alpha-toxin. With permeabilized A10 cells, 2-[14C]POG was mainly converted into lipolytic products of a lipase pathway, monoacylglycerol (MG) and fatty acid (FA); very little radioactivity was incorporated into triacylglycerol (TG) or phospholipid (PL) via reactions catalyzed by either DAG acyltransferase, cholinephosphotransferase, or DAG kinase. Similar results were obtained in experiments with 1-stearoyl-2-[1-14C]arachidonoyl-sn-glycerol. The conversion of 2-[14C]POG into PL and TG was not enhanced by the addition of 1 mM ATP-MgCl2, 1 mM CDP-choline, or 1 mM oleoyl-CoA to the alpha-toxin-treated A10 cells. The formation of FA and MG by permeabilized A10 cells was inhibited by DAG lipase inhibitors, U-57,908 (50 microM) and tetrahydrolipstatin (1-25 nM). The predominant contribution of the lipase pathway to the metabolism of a long-chain DAG, 2-[14C]POG, by alpha-toxin-treated A10 cells is similar to results for the degradation of [3H]diC8 by intact A10 cells.

Animals↗
PubMed1992

Risk factors for tumors of the brain and meninges: results from the Adelaide Adult Brain Tumor Study.

A population-based case-control study of incident primary brain tumors in adults was carried out in Adelaide, Australia in the period 1987 through 1990. It included 110 subjects with newly diagnosed primary glioma, 60 subjects with meningioma and 417 controls selected from the Australian Electoral Roll and frequency-matched to cases for age (within 2 years), sex and postal code. Some interesting new associations were found: (1) an increased risk of glioma in women who reported working with cathode-ray tubes (relative risk = 4.1, 95% confidence interval: 1.3-13.2); (2) a decreased risk of glioma in those with a history of allergic diseases (relative risk = 0.5, 95% confidence interval: 0.3-0.9); and (3) an increased risk of meningioma in those exposed to passive smoking from a spouse, especially amongst females (relative risk = 2.7, 95% confidence interval: 1.2-6.1). A pooled analysis of the multi-center group of studies to which the present study belongs should allow more confident claims concerning risk factors for brain tumors.

Adult↗
PubMed1992

Amalgam fillings, diagnostic dental x-rays and tumours of the brain and meninges.

A population-based case-control study of incident brain tumours in adults in Adelaide, South Australia considered possible associations of exposures to amalgam fillings and diagnostic dental X-rays with subsequent development of glioma and meningioma. The study, conducted in 1987-1990, recorded data from 110 subjects with glioma, 60 with meningioma and 417 controls. Principal findings were unexplained decreased risks for glioma associated with both exposure to amalgam fillings (age- and sex adjusted relative risk = 0.47, 95% confidence interval: 0.25-0.91; P = 0.02) and to diagnostic dental X-rays (adjusted relative risk = 0.42; 95% confidence interval: 0.24-0.76; P = 0.004), and a possible increased risk for meningioma in males exposed to dental X-rays. The choice of the unexposed comparison group is important in determining if an increased risk is associated with panoramic or full-mouth X-rays in glioma.

Adult↗
PubMed1992

Colorectal cancer. Recent developments and continuing controversies.

In the last 2 years, much progress has been made in colorectal cancer research. Many of the findings, especially those involving adjuvant therapy, have important clinical applications. For example, fluorouracil (5-FU) (Adrucil) combined with levamisole hydrochloride (Ergamisol) is now recommended as adjuvant therapy for patients with Dukes' stage C (III) disease. Some aspects of colorectal cancer remain controversial, particularly screening recommendations and monitoring of carcinoembryonic antigen levels.

Carcinoembryonic Antigen↗
PubMed1992

Minocycline hyperpigmentation: model for in situ phagocytic activity of factor XIIIa positive dermal dendrocytes.

Pigmentary disorders resulting from the prolonged use of the semisynthetic tetracycline derivative antibiotic, minocycline, are rare but well recognized sequelae of ingestion of this drug. We present two cases of women with bullous pemphigoid who developed blue-black pigmentation in areas of scarring on the legs after oral minocycline therapy. On histologic examination, the deposited pigment was localized within dendritic cells limited to the upper dermis. Immunohistochemical analysis revealed these cells to be factor XIIIa positive dermal dendrocytes which was confirmed by transmission electron microscopy. We believe these cases demonstrate, in-situ, the phagocytic capabilities of this recently described cell population.

Aged↗
PubMed1992

Gender-related motivational differences in participation in an organized seniors fitness program: moving beyond sex-role stereotypic motives.

Primary reasons for senior adults' participation in a fitness program were examined in two groups to assess gender-related differences. 30 senior adults or "beginners" had just enrolled in the program, while 43 "veterans" had participated for about three years. Among "beginners" women were more likely to participate because "daytime meetings were offered" and "people I trust recommend it" but there were no gender differences among "veterans." Close examination of responses indicated that differences among "beginners" no longer obtained because "veteran" men's motivations increased to resemble those of women. Examination of these motivational shifts as well as those which approached significance is in progress with a larger sample.

Aged↗
PubMed1990

Carcinoid tumors of the thymus.

Carcinoid tumors arising in the thymus are rare. Since Rosai and Higa in 1972 distinguished these neoplasms from thymomas, fewer than 100 cases have been reported in the world literature. In a 38-year review (1950 to 1988) of surgically treated thymic tumors at Henry Ford Hospital, only 7 cases of thymic carcinoids were identified. These 6 men and 1 woman ranged in age from 27 to 70 years (mean, 48 years) at diagnosis. Follow-up was available in all patients with the longest survival being 12 years in 2 patients, and the shortest, 1 year, in 1. Recurrences and/or metastases developed in 4 of 7 patients between 1 and 9 years after initial resection. Recurrences were treated by reexcision in addition to radiation treatment and chemotherapy in 3 patients and reexcision with radiation treatment alone in 1 patient. A review of the literature along with our experience suggests that thymic carcinoids have a biological behavior distinct from thymoma in terms of cell origin, associated syndromes, neoplastic behavior, and prognosis. An aggressive surgical approach with complete initial excision of the tumor and of subsequent recurrences, along with radiation and probably chemotherapy, is the best available treatment today.

Adult↗
PubMed1990

Hemangiomas with localized nodular proliferation of the liver. A suggestion on the pathogenesis of focal nodular hyperplasia.

Multiple cavernous hemangiomas circumscribed by focal regenerative nodules of hepatocytes were incidental findings at the autopsy of two elderly men. Neither patient was on steroids or had venous thrombosis. The lesions were not typical for other nodular proliferations of the liver, such as focal nodular hyperplasia, nodular regenerative hyperplasia, or liver cell adenoma, and they have not been previously reported. We also explore the roles of vascular malformation, oral contraceptives, and thrombosis in the pathogenesis of localized nodular proliferation of the liver.

Aged↗
PubMed1990

The safety of dermatologic liposuction surgery.

The safety of liposuction surgery begins with appropriate preoperative evaluation and patient selection. Operative considerations include the type of anesthesia used, the volume of fat aspirated, and the liposuction technique utilized. Results from a recent survey revealed that liposuction surgery can be extremely safe when done under local anesthesia with conservative fat removal.

Accident Prevention↗
PubMed1989

Interlocking figure-of-8 closure of the sternum.

Sternal dehiscence and mediastinitis are two of the most severe complications of a median sternotomy. A technique of closure is described that appears to provide a more stable sternal approximation without any increase in overall complication rate. Using this technique in 978 consecutive patients, no cases of sternal dehiscence or mediastinitis have been seen.

Adult↗
PubMed1989

Adenoid cystic carcinoma of the lacrimal sac.

Adenoid cystic carcinoma is the most common epithelial malignancy of the lacrimal gland and minor salivary glands. Its occurrence in the lacrimal drainage system is extremely rare. A 57-year-old woman presented with epiphora and a mass in the lacrimal sac, which proved to be an adenoid cystic carcinoma. Histologically, it appeared to arise from the wall of the lacrimal sac, and both the lacrimal gland and maxillary antrum were uninvolved by tumor. Despite aggressive surgical intervention, recurrence and metastasis developed. Adenoid cystic carcinoma must be considered in the differential diagnosis of epiphora.

Biopsy↗