PubMed Health⌕ Search

Biomedical subjects

R Nagle

Publications and source records attributed to R Nagle.

At least 19 recordsLinked to original sources
PubMed2000

A microfluidic system for high-speed reproducible DNA sizing and quantitation.

Microfabrication technology was used to develop a system consisting of disposable glass chips containing etched channels, reagents including polymer matrix and size standards, computer-controlled instrumentation for performing electrophoretic separations and fluorescence detection of double-stranded DNA, and software for automated data analysis. System performance was validated for separation and quantitation reproducibility using samples varying in amount and size of DNA fragments, buffer composition, and salt concentrations. Several applications of the microfluidic system for DNA analysis have been demonstrated, such as of polymerase chain reaction (PCR) products, sizing of plasmid digests, and detection of point mutations by restriction fragment length polymorphism (RFLP) mapping.

Animals↗
PubMed1999

Induction of melanoma in TPras transgenic mice.

In order to study the oncogenesis of melanocytes, transgenic mouse lines were established that express a mutated human Ha-ras (TPras) gene in pigment producing cells. The ras transgenic mice exhibit an altered phenotype, including melanocytic hyperplasia and a muted agouti coat, indicative of hyperproliferative melanocytes. These mice and their wild-type littermates have been subjected to a variety of carcinogenesis protocols, including 7, 12-dimethylbenz-[a]anthracene (DMBA), 12-O-tetradecanoylphorbol-13-acetate (TPA) and UV radiation exposure. Topical DMBA treatment of TPras mice resulted in a high incidence of melanomas. Metastatic lesions were observed in skin, lungs and lymph nodes. TPA treatment of TPras mice induced a small number of papillomas but no nevi or melanomas. UV light exposures induced papillomas in negative littermate and melanomas in some albino TPras mice. These results show that melanocytes expressing an activated Ha-ras in the TPras transgenic mice are susceptible to induction of melanoma by DMBA.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1998

Extension of useful reagent shelf life beyond manufacturers' recommendations. Cell Markers Committee of the College of American Pathologists.

OBJECTIVE: The College of American Pathologists Cell Markers Committee designed a study to evaluate the use of immunohistochemistry primary antibodies beyond manufacturers' recommended dates. METHODS: Pathologists were asked to save aliquots of primary antibodies during mid-1997 so that by spring 1998 the reagents would be "outdated" according to manufacturers' recommendations. Three tumors were immunostained both in mid-1997 and early 1998 (using outdated reagents in 1998). Two hundred twenty-one laboratories participated. PATIENT SAMPLES: Immunostained materials consisted of an angiomyolipoma immunostained for muscle-specific actin and HMB-45, a melanoma immunostained for S100 protein and HMB-45, and a large cell lymphoma immunostained for common leukocyte antigen and HMB-45. Blocks from the same tumor were used in each instance. MAIN OUTCOME MEASURE: We compared the immunostaining results as a percentage of laboratories indicating a positive or negative immunohistochemical result between the 1997 and 1998 time points. RESULTS: Only minor differences were identified for the 221 reporting laboratories in 1998 as compared with those in 1997. CONCLUSIONS: The data suggest review of the Health Care Financing Administration's ruling on extending the useful reagent shelf life beyond manufacturers recommendations. Similar studies using more inherently quantitative methodology are suggested.

Antibodies↗
PubMed1997

Pathologic and clinical findings in patients with cyclosporiasis and a description of intracellular parasite life-cycle stages.

Cyclospora cayetanensis has been observed in the feces of persons with prolonged diarrhea. A description of the symptoms and histopathologic findings for patients with cyclosporiasis is presented. The intracellular life-cycle stages of these parasites in the enterocytes of patients will also be described. Seventeen Peruvian patients positive for Cyclospora organisms were surveyed and underwent endoscopy, and their symptoms were recorded. Patients presented with gastrointestinal symptoms, including diarrhea, flatulence, weight loss, abdominal discomfort, and nausea. Jejunal biopsies showed an altered mucosal architecture with shortening and widening of the intestinal villi due to diffuse edema and infiltration by a mixed inflammatory cell infiltrate. There was reactive hyperemia with vascular dilatation and congestion of villous capillaries. Parasitophorous vacuoles contained sexual and asexual forms. Type I and II meronts, with 8-12 and 4 fully differentiated merozoites, respectively, were found at the luminal end of epithelial cells. These findings demonstrate the complete developmental cycle associated with host changes due to Cyclospora organisms.

Animals↗
PubMed1996

Randomized study of neoadjuvant testicular androgen ablation therapy before radical prostatectomy in men with clinically localized prostate cancer.

PURPOSE: We determined whether 12 weeks of neoadjuvant testicular androgen ablation therapy using a luteinizing hormone-releasing hormone agonist could improve pathological outcomes in men undergoing radical retropubic prostatectomy for clinically localized (stages T1C, T2A and T2B) prostatic carcinoma. MATERIALS AND METHODS: A total of 56 participants was randomized to receive either monthly injections of a luteinizing hormone-releasing hormone agonist at 4-week intervals followed by radical retropubic prostatectomy (28) or to undergo immediate radical retropubic prostatectomy alone (28). Operations were performed via similar technique and all prostatic specimens were processed histologically in their entirety. RESULTS: There was no improvement in pathological outcome using luteinizing hormone-releasing hormone agonist preoperatively compared to surgery alone. Of 28 men undergoing immediate radical retropubic prostatectomy 23 had organ-confined (17) or specimen-confined (6) disease versus 22 of 28 who received luteinizing hormone-releasing hormone neoadjuvant therapy for 12 weeks preoperatively (16 with organ-confined and 6 with specimen-confined disease, p = 1.00). In addition, when the study population was analyzed by pretreatment prostate specific antigen (PSA) levels (10 ng./ml. or less, or greater than 10 ng./ml/) there was also no difference in pathological outcome (p = 0.65 for PSA greater than 10 and p = 0.32 for PSA less than 10). CONCLUSIONS: Neoadjuvant androgen ablation therapy for 12 weeks before radical prostatectomy in patients with clinically localized adenocarcinoma of the prostate does not result in improved pathological outcomes.

Adenocarcinoma↗
PubMed1993

Specific alterations in the expression of alpha 3 beta 1 and alpha 6 beta 4 integrins in highly invasive and metastatic variants of human prostate carcinoma cells selected by in vitro invasion through reconstituted basement membrane.

Highly invasive cell subpopulations from a human prostate carcinoma cell line, PC-3, were selected for by allowing the parental PC-3 cells to invade through reconstituted basement membrane, Matrigel. These cells were collected, cultured and then selected further by repeated invasion through the in vitro invasion chamber. The invasive subpopulations (I-PC3 (2) and (3)) were found to be approximately 15-fold more invasive in vitro than the parental cells, had a distinct rounded morphology in culture, and proliferated more rapidly than the parental cells. When injected either subcutaneously or intraperitoneally into immunocompromised SCID mice, the I-PC3 cells were found to form tumors at the primary sites and to be highly invasive and metastatic. In contrast, the parental PC-3 cells formed tumors at the site of inoculation in these mice but failed to invade or metastasize. The I-PC3 cells attached equally as well as PC-3 cells to fibronectin, laminin, collagen type IV and vitronectin, but unlike the parental PC-3 cells these invasive variants failed to spread on any of these substrates. On Matrigel, the PC-3 cells became highly organized, whereas the I-PC3 cells remained rounded, clumped together and penetrated into the Matrigel. Biochemical analysis of the expression of adhesion proteins and integrins demonstrated that whereas the parental cells synthesized and secreted substantial amounts of fibronectin, the I-PC3 cell variants did not secrete any fibronectin. Although both PC-3 and I-PC3 cells expressed equivalent levels of cell surface alpha v beta 3, alpha 2 beta 1 and alpha 5 beta 1 integrins, the expression of the alpha 3 beta 1 integrin, which is expressed at very high levels on the parental PC-3 cells, was drastically reduced on the invasive I-PC3 cells. This decrease in expression of alpha 3 occurred also at the level of mRNA expression. Finally, whereas the PC-3 cells express alpha 6 beta 1, in the invasive I-PC3 cells the alpha 6 subunit was associated mostly with the beta 4 subunit. Since the alpha 6 beta 4 integrin is analogous to the A9 tumor antigen which is associated with aggressive human squamous cell carcinomas, the apparent overexpression of alpha 6 beta 4 may also participate in the aggressive behavior of these variant prostate carcinoma cells. Alterations in the expression of the alpha 3 beta 1 and alpha 6 beta 4 integrins may thus allow these cells to become more invasive, and lead to an increased propensity for metastasis.

Antigens, Surface↗
PubMed1991

Establishment of two new cell lines derived from human breast carcinomas with HER-2/neu amplification.

Two human cell lines (UACC-812 and 893), both containing significant amplification of the HER-2/neu gene, were established from biopsy specimens of breast carcinomas. One patient had Stage II breast carcinoma; the other had metastatic disease. Characterisation of these lines has revealed that both are highly aneuploid containing multiple clonal chromosome alterations, have doubling times near 100 h, and are oestrogen and progesterone receptor negative. Electron microscopy demonstrates that both lines contain numerous microvilli, cytoplasmic filaments, multivesicular bodies, and desmosomes. Immunoblot analysis for P-glycoprotein using the monoclonal antibody C219 was negative for both patient cell lines. These relatively rare cell lines may represent a useful model to investigate human breast carcinomas.

Adult↗
PubMed1991

Vascular abnormalities in experimental and human lymphatic filariasis.

Whereas clinical descriptions of grotesque lymphedema and standard light microscopy in human filariasis have elucidated the natural progression of this disease, the link between the nematode and vascular abnormalities including elephantiasis remains poorly understood. Accordingly, we examined the nature and distribution of lymphatic and blood vascular derangements in a variety of tissues and organs from 37 ferrets acutely and chronically infected with Brugia malayi and in 15 patients with Wuchereria bancrofti or Brugia malayi infestation (resected skin, subcutaneous tissue, and lymph nodes) using light and transmission electron microscopy, immunohistochemistry, and in vivo microscopy. In ferrets, eosinophilic abscesses and epithelioid and giant cell granulomas with fragmented worms in various stages of disintegration were found in multiple organs. Blood microvasculopathy consisted of endothelial hyperplasia, focal thickening and stenosis, vessel obliteration with marked perivascular infiltration of lymphocytes, plasma cells, eosinophils, and numerous large macrophages laden with a coarse golden-brown pigment. Endothelial ballooning and swelling, pavementing, denuding, scarring, and sludge formation were seen along with high endothelium in atypical locations. Dilated lymphatics were most prominent near adult worms and showed plump endothelium, thickened walls and valves, thrombus formation, and often perilymphangitis and adjacent tissue fibrosis. In vivo microscopy showed wriggling live adult worms in dilated incompetent sludge-filled groin lymphatics even when microfilaremia and peripheral edema were absent. In human tissues, in addition to "pachyderm" skin changes (keratosis, papillomatosis, acanthosis and collagen deposition), there was blood vessel and lymphatic vasculopathy similar to ferrets (angiocentric inflammation, congestion, vasculitis, thrombosis, thickened vessel walls, dilated lymphatics, lymphangitis, reactive lymph nodal hyperplasia and nodal fibrosis). These changes reflect generalized endothelial damage due to worm products, physical injury to valves and vessel walls from lymphatic-dwelling live worms, and host immune reactivity. Whereas adult worms target the lymphatic apparatus, their offspring and the host immune response primarily affects the blood microvasculature.

Animals↗
PubMed1987

Lymphatic endothelial cell line (CH3) from a recurrent retroperitoneal lymphangioma.

An endothelial cell line derived from a massive recurrent chyle-containing retroperitoneal lymphangioma was isolated in monolayer culture. Scanning and transmission electron microscopy and immunohistochemistry confirmed a close resemblance to blood vascular endothelium with typical cobblestone morphology, positive immunofluorescence staining for endothelial marker Factor VIII-associated antigen and fibronectin, and prominent Weibel-Palade bodies. The endothelial cells also exhibited other ultrastructural features characteristic of lymphatic endothelium, including sparse microvillous surface projections, overlapping intercellular junctions, and abundant intermediate filaments. This endothelial cell line represents a new source of proliferating lymphatic endothelium for future study, including structural and functional comparison to blood vascular endothelium.

Adult↗
PubMed1987

Delineation of a novel pre-B cell component in plasma cell myeloma: immunochemical, immunophenotypic, genotypic, cytologic, cell culture, and kinetic features.

A novel pre-B cell component in direct and cultured myeloma bone marrow material has been delineated by using immunochemistry and flow cytometry techniques. Our phenotypic studies suggest a novel hybrid expression of pre-B and plasma cell antigens with coexpression of cytoplasmic mu, common acute lymphoblastic leukemia antigen, terminal deoxynucleotidyl transferase, and plasma cell antigens (PCA-1 and PC-1). This suggests that myeloma pre-B-like cells are aberrant malignant cells and not normal pre-B lymphocytic counterparts. With the advantage of a pure and stable source of these cells from M3 culture to allow molecular characterization, we performed one- and two-dimensional gel electrophoresis and Western blotting. We found that the cytoplasmic mu in myeloma pre-B-like cells has a molecular weight of 74,000 daltons and an isoelectric point of 6.3 and that it is strikingly homogeneous and discrete in size and charge compared with standard secretory mu, which suggests an aberrant, mutant, or monoclonal form of mu. Monoclonality was further evidenced by heavy- and light-chain immunoglobulin gene rearrangements demonstrated with JH and C kappa probes. We also established that this novel myeloma pre-B component is a major proliferative element as determined by double-labeling experiments with phenotype coupled to labeling/proliferative indexes. Our stimulatory studies indicate some capacity of these cells to mature on exposure to phorbol esters. These myeloma pre-B cells may represent the stem cell or self-renewal component in myeloma. Our establishment of these cells in long-term culture offers a considerable asset in studying the immature cells, which may be critical to the immortalization of myeloma.

B-Lymphocytes↗
PubMed1986

The growth of benign prostatic hypertrophy in semisolid agar culture.

Tissue samples from transurethrally resected benign prostatic hypertrophy (BPH) in 29 patients were disaggregated into single cells and cultured in semisolid media. In 15 cultured specimens not overgrown with bacteria or fungus, colony formation occurred in seven (47 per cent). The median plating efficiency was 0.036 per cent with a range of 0.0005 to 0.9 per cent. Studies of the cells forming the colonies demonstrated histochemical, immunohistologic, morphologic and ultrastructural findings characteristic of an epithelial origin. The results suggest a potential utility of colony forming assays in the study of benign as well as malignant cells. These BPH culture studies were limited by microorganism contamination and low yields from the disaggregation technique.

Agar↗