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Biomedical subjects

R L Garcia

Publications and source records attributed to R L Garcia.

At least 19 recordsLinked to original sources
PubMed1992

Distribution of Leu-7 antigen (HNK-1) in thyroid tumors: its usefulness as a diagnostic marker for follicular and papillary carcinomas.

The reactivity of the anti-Leu-7 monoclonal antibody was tested in 39 neoplastic and nonneoplastic thyroid tissue specimens. These included eight colloid goiters, 14 follicular adenomas, nine papillary carcinomas, five follicular carcinomas, two medullary carcinomas, and one metastatic follicular carcinoma in bone. We observed strong cytoplasmic and/or cell membrane positivity in all follicular and papillary carcinomas, in both primary and metastatic tumors. However, the medullary thyroid carcinomas tested were negative. We also observed weak and only occasional staining with anti-Leu-7 antibody in colloid goiter and follicular adenomas. The staining in the benign thyroid lesions was usually focal, less than 10% of the cells; however, in cases of follicular and papillary carcinomas, both in primary and metastatic tumors, the staining was diffuse and strong. Some of the colloid material in colloid goiters and follicular adenomas showed faint homogenous staining with anti-Leu-7 antibody. Our findings suggest that anti-Leu-7 monoclonal antibody is a marker that may facilitate the differentiation between benign and malignant thyroid lesions, with the exception of medullary carcinoma. In addition, caution should be taken when using this antibody to diagnose metastatic lesions, as other metastatic carcinomas have also been reported to be positive. This antibody should be used in conjunction with a panel of antisera to complement a morphologic diagnosis.

Adenocarcinoma↗
PubMed1990

Platelets mediate glomerular cell proliferation in immune complex nephritis induced by anti-mesangial cell antibodies in the rat.

We investigated whether platelets, which are rich in growth factors, could mediate glomerular cell proliferation in immune complex glomerulonephritis (GN) in the rat induced with an antibody directed against the Thy-1 antigen present on mesangial cells. Rats were depleted of platelets (mean platelet count less than 20,000/mm3) with goat anti-rat platelet IgG before induction of GN and platelet depletion was maintained for 48 hours. At 72 hours sections were immunostained for cyclin, an S-phase-related nuclear antigen, to identify proliferating cells, and for the common leukocyte antigen (CD45) to identify infiltrating leukocytes. Platelet depleted rats had fewer proliferating resident glomerular cells (CD45-, cyclin+) compared to controls (0.8 +/- 0.5 vs. 2.8 +/- 1.4 cells/glom cross section, P less than 0.01) and better renal function (creatinine 1.07 +/- 0.12 vs. 1.27 +/- 0.15 mg/dl, P less than 0.05). These effects were not due to changes in circulating or glomerular leukocyte counts, complement, or glomerular antibody binding. These studies provide the first direct evidence that platelets mediate glomerular (probably mesangial cell) proliferation in antibody-mediated GN.

Animals↗
PubMed1989

Analysis of proliferative grade using anti-PCNA/cyclin monoclonal antibodies in fixed, embedded tissues. Comparison with flow cytometric analysis.

Cell kinetic information is an important adjunct to histologically-based tumor classifications. Presently, cell kinetic data can be obtained from slide-based material only with monoclonal antibodies such as Ki-67, which require the use of frozen sections and cannot be applied to archival, paraffin-embedded material. Monoclonal antibodies have recently been generated to PCNA/cyclin, a 36 kd, S-phase-associated nuclear protein. The authors investigated whether monoclonal antibody 19A2 could be used to identify proliferating cells within fixed, embedded tissue sections. Deparaffinized sections of 41 methacarn-fixed human tumors were immunostained with 19A2 using a streptavidin biotin immunoperoxidase system. A semiquantitative scoring system was used to evaluate the fraction of cells that were PCNA/cyclin-positive, and this score was compared with cell kinetic data obtained from parallel flow cytometric S-phase analysis that had been performed on fresh samples of the same tumors. While there was general agreement between the slide-based, antibody-derived and the flow cytometrically-derived cell kinetic information, some discrepancies were observed. Some of the latter represented cases in which the anti-PCNA/cyclin antibody preparations demonstrated significant heterogeneity in the numbers of proliferating cells in different regions of the tumor. In other cases, a significant fraction of the positive cells corresponded to nontumor stromal and/or inflammatory cells. In these cases, the slide-based method provided more information about the tumor cell population than did the flow cytometry data. It is concluded that semiquantitative immunocytochemical analysis with anti-PCNA/cyclin antibodies may represent a simple, reproducible, yet powerful technique for the routine analysis of cell kinetic data in alcohol-fixed, paraffin-embedded tissue by the surgical pathologist.

Antibodies, Monoclonal↗
PubMed1979

Topical tretinoin, hydroquinone, and betamethasone valerate in the therapy of melasma.

Twenty adult female patients with melasma were followed over a ten week clinical trial in which a combination of depigmenting agents was used daily. Past clinical experience and objective assessment point to enhanced efficacy of this simple depigmenting combination. Certainly, most of depigmenting agents at our command to date have been relatively ineffective. Even this new combination is not the final answer. The purpose of this study is to provide the clinician with a simple yet effective and readily accessible combination of commercially-formulated and available depigmentary agents. A stable combination in a single vehicle with greater efficacy remains to be perfected.

Administration, Topical↗
PubMed1979

Halo congenital nevus.

A case of halo congenital nevus is reported in a fifteen year old Mexican-American girl with pre-existing vitiligo.

Adolescent↗
PubMed1979

Oligosymptomatic Melkersson-Rosenthal syndrome.

A patient with cheilitis granulomatosa and sialopenia is presented herein as a variant of the oligosymptomatic type of Melkersson-Rosenthal syndrome. Evidence is presented to support its possible neurotrophic origin.

Adult↗
PubMed1979

Factitious pseudoainhum of the nipple.

A patient with a cosmetically disfiguring swelling of his nipple for many years was found to have factitious mechanical pseudoainhum. The possibility of occult mechanical constriction as the cause of acute or chronic deformities of appendages is emphasized.

Ainhum↗
PubMed1978

Endobronchial metastasis from cancer of the breast.

Endobronchial metastasis is reported to occur in less than 5% of the autopsies of patients dying with extrathoracic malignant neoplasms. Frequently associated primary tumors include those of the kidney, pancreas, colon, ovary, and thyroid. To our knowledge, this is the first report of a case of cancer of the breast which metastasized to the mucosa of a major bronchus. The possible factors involved in the widespread, early unusual spread in this 25-year-old woman are discussed.

Adult↗