Search PubMed⌕ Search

Biomedical subjects

R A Robinson

Publications and source records attributed to R A Robinson.

At least 127 records · Page 7Linked to original sources
PubMed1990

p185neu expression in human lung adenocarcinomas predicts shortened survival.

p185neu is the protein product of the HER2/neu protooncogene. This protein has characteristics of a tyrosine kinase growth factor receptor and is postulated to be important in human carcinogenesis. To define the significance of the expression of this protein in human non-small cell lung cancer, 55 tumors from patients with squamous cell carcinoma (16), adenocarcinoma (29), or large cell carcinoma (10) of the lung were examined for p185neu using immunohistological methods. Five of 16 squamous cell carcinomas and 10 of 29 adenocarcinomas were found to overexpress p185neu relative to levels of expression seen in uninvolved bronchiolar epithelium. For the adenocarcinomas, p185neu expression was associated with older age (66.6 +/- 10.1 versus 57.5 +/- 10.8 years) (P = 0.04) and shortened survival (83.7 +/- 94.1 versus 188.5 +/- 120 weeks) (P = 0.01). In this group, using Cox's multivariate survival analysis, p185neu expression was found to be a significant determinant of survival (P = 0.04) even after accounting for the effect of tumor stage. For the squamous cell carcinomas, p185neu expression was not correlated with any of our clinicopathological parameters. Our findings indicate that non-small cell lung cancers which express p185neu do so at levels higher than that found in normal bronchiolar epithelium, and expression in adenocarcinomas of the lung is independently associated with diminished survival intervals.

Adenocarcinoma↗
PubMed1990

Absorbable staples in continent ileal urinary pouch.

Continent ileal urinary reservoirs were created in dogs to study absorbable surgical staples. Within each pouch, certain controlled observations were possible. The staples and chemically similar polyglactin absorbable sutures caused almost identical tissue reactions. The staples outlasted the sutures, probably because of greater size. Inverted and everted staple closures worked equally well. It appears feasible to consider clinical urinary diversion with absorbable staples, a time-saving method.

Animals↗
PubMed1990

Hemangiopericytoma--the role of radiotherapy.

Between 1955 and 1987, 15 patients with hemangiopericytomas were seen at the University of Iowa Hospitals and Clinics. Twelve of these were thought to have localized tumors and three had metastatic disease at diagnosis. Seven of the 12 patients with localized disease were treated with surgery alone, four were treated with surgery and postoperative radiation therapy, and one was treated with surgery and chemotherapy. Only one of the seven patients initially treated with surgery alone has remained continuously free of disease, although two others were salvaged with radiation therapy. In contrast, all four patients initially treated with surgery and postoperative radiation therapy have remained alive with no evidence of disease in spite of the fact that three of these patients had gross residual tumor at the time of irradiation. Ten patients received radiation therapy at some stage of their management. Local tumor control was achieved at all sites receiving greater than 5500 cGy. Six patients received chemotherapy sometime during the course of their management, although no complete or partial responses were observed. In this small series, mitotic activity was not an accurate predictor of biologic behavior.

Adolescent↗
PubMed1990

Intraductal breast carcinoma: initial results of a morphometric study using computerized digital image analysis.

Extensive ductal carcinoma in situ (DCIS) and necrosis in breast carcinoma have been correlated with a higher incidence of local recurrence in patients treated with breast-conserving surgery and radiotherapy. In an attempt quantitatively to assess duct size distribution and necrosis in DCIS, the authors devised a method utilizing computerized digital image analysis. The method and results of a pilot study comparing 21 patients with DCIS, and 21 normal breast specimens are presented. Normal breast tissue from autopsy material revealed a mean duct diameter of 90 microns, whereas the mean diameter of ducts in patients with DCIS was 359 microns (P less than 0.001). The presence of necrosis in DCIS correlated strongly with average duct size. Of the ducts larger than 360 microns in diameter 94% exhibited intraductal necrosis, whereas ducts less than 360 microns showed necrosis in only 30% of the measurements. Ducts with necrosis revealed a mean diameter of 498 microns versus 198 microns in ducts without necrosis (P less than 0.001). The authors suggest that necrosis develops in response to tumour cell hypoxia associated with cross-sectional duct expansion in DCIS. This growth pattern predisposing to tumour cell hypoxia could be a factor contributing to radioresistance and increased local recurrence.

Adult↗
PubMed1990

Silver-stained nucleolar organizer regions in the differentiation of prostatic hyperplasia, intraepithelial neoplasia, and adenocarcinoma.

Nucleolar organizer regions (NORs) are loops of chromosomal DNA that ultimately direct the development of the nucleolus. These NORs are associated with argyrophilic acidic nonhistone proteins which have allowed the demonstration of NORs by a simple silver stain. This staining technique has been used to examine the number of silver-stained NORs (AgNORs) in malignant and benign conditions, and, in general, AgNOR numbers are increased in malignant tissues when compared with normal or benign conditions. More recently, this technique has been applied to premalignant lesions with varying results. We applied this silver stain to prostate lesions where nucleolar features are of diagnostic importance. The stain was applied to ten cases of prostatic hyperplasia, ten cases each of prostatic intraepithelial neoplasia (PIN) grades 1 through 3, and ten cases each of low grade, intermediate grade, and high grade adenocarcinoma. The counting was performed by image analysis. A significant mean difference did exist between low grade and the two higher grades of adenocarcinoma. There was no significant difference in AgNOR counts per nucleus in hyperplasia, PIN, or adenocarcinoma or between the three grades of PIN. The AgNOR silver stain is not useful in the differentiation of hyperplasia, the three grades of PIN, and adenocarcinoma. Also because of overlap among the three grades of adenocarcinoma, it is not useful in the differentiation of these lesions.

Adenocarcinoma↗
PubMed1989

Factitious microcalcifications in breast biopsy material: laboratory-induced error by use of tattoo powder for specimen mammography.

A xeromammogram led to the surgical excision of a calcified breast lesion on a 66-year-old female. Before specimen mammography was performed, the excised tissue was oriented with tattoo pigment. The specimen mammogram then revealed multiple calcifications caused by unsuspected radio-opaque material in the tattoo pigment, and the original calcifications were obscured. This case demonstrates the hazards involved utilizing tattoo powders for orienting xeromammographically discovered specimens.

Aged↗
PubMed1989

Mutational analysis of sodium butyrate inducible elements in the human immunodeficiency virus type I long terminal repeat.

Sodium butyrate induces gene expression directed by the human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) in HeLa cells. Inducible regions of the HIV-1 LTR were elucidated by using 5' and 3' LTR deletion mutants and LTR site-directed mutants within the Sp1 binding sites and the trans-activation responsive (TAR) region. Two LTR regions inducible by sodium butyrate were located: one at -117 to -103 (distal site) and one at -65 to -17 (proximal site). In HeLa cells trans-fected with pZ6neo, a biologically active HIV-1 proviral clone, sodium butyrate stimulated virus production following a 3-day treatment. Inducibility of HIV-1 gene expression by sodium butyrate was unrestricted in many human cell types, including CD4+ lymphoid cells and non-CD+ brain cells and fibroblasts. Additionally, sodium butyrate transiently induced HIV-2 LTR-directed gene expression in HeLa cells. Using the HIV-1SF-2 tat gene cotransfected with pLTR-CAT site-directed TAR mutants in HeLa cells, the boundaries of tat-trans-activation were delineated more precisely. These results suggest that the induction of HIV-1 gene expression is mediated by the interaction of sodium butyrate with cellular transcription factors that bind to the HIV-LTR.

Base Sequence↗
PubMed1989

Generation of hybrid human immunodeficiency virus by homologous recombination.

Human immunodeficiency virus (HIV) type 1, isolated from diverse sources, exhibits genomic diversity. The mechanisms by which the genomic diversity takes place in individuals exposed to multiple virus isolates is yet to be elucidated. Genetic variation, in general, might result from mutagenic events such as point mutations, rearrangements (insertions and deletions), and recombination. In an attempt to evaluate the process of genetic diversity, we designed experiments to analyze recombination between HIV DNAs by using DNA transfection in cell cultures. Here we report the successful recombination between truncated HIV proviral DNAs with an overlap homology of 53 base pairs that leads to the formation of viable hybrid virus. Recombination was also seen between exogenous DNA introduced into cells and homologous HIV sequences resident in the cells. These results indicate that recombination among various HIV isolates may play a significant role in the generation of genetic diversity of HIV. Further, the method used here enables the construction of hybrid HIV genomes to identify the viral determinants responsible for tropism, replication, and cytopathic effects.

Base Sequence↗
PubMed1989

Adenoid cystic carcinoma. A clinicopathologic study with flow cytometric analysis.

Forty-five patients with adenoid cystic carcinoma (ACC) of salivary glands were retrospectively studied to determine the prognostic use of DNA ploidy analysis compared with clinicopathologic features. Nuclear suspensions were prepared from 37 of these tumors by the Hedley technique on paraffin-embedded material. The DNA content was analyzed by flow cytometry after propidium iodide staining. Thirty-five tumors were diploid and 2 were tetraploid. Mean survival was 117 and 52 months for the diploid and tetraploid patients, respectively. The median S-phase fraction (Spf) of the 35 diploid tumors was 4.45%. Of the 17 diploid patients who died of disease, there were 11 tumors with high Spf (greater than 4.45%) and 6 tumors with a low Spf (P less than 0.05 chi-square test). The presence of more than 30% of a solid pattern in the tumor was strongly associated with poor median survival in Kaplan-Meier survival curve analysis (P less than 0.05 log rank test). Grade, stage, recurrence, and metastases were also found to be important prognostic factors. Because few tumors were nondiploid, these results suggest that S-phase fraction analysis may be a more useful prognostic indicator than ploidy classification.

Actuarial Analysis↗
PubMed1989

Microbial transformation of the tetrazolinone herbicide f5231.

Microbial transformation of the tetrazolinone herbicide F5231 was accomplished with the filamentous fungus Absidia pseudocylindrospora Hesseltine et Ellis (ATCC 24169). The fungus converted the herbicide to six metabolites which were identified spectrally by mass, infrared, and nuclear magnetic resonance spectroscopy.

Journal Article↗
PubMed1989

Salivary gland carcinosarcoma: true malignant mixed tumor.

True malignant mixed tumor, or carcinosarcoma, of salivary gland origin is rare. Only 19 cases have been reported in the literature and a review of cases seen at the University of Iowa over the last 60 years yielded only two. In one case the mesenchymal component of the tumor contained both osteosarcoma and chondrosarcoma. In the second case, the history and the histology suggest a progression from carcinoma ex pleomorphic adenoma to a carcinosarcoma. These features are documented in this report and literature review.

Carcinosarcoma↗
PubMed1989

Intraparotid nodular fasciitis.

We describe two cases of nodular fasciitis arising within the parotid glands of two patients, a 42-year-old man and a 2 1/2-year-old boy. The clinicopathologic, immunohistochemical, and ultrastructural features of this lesion and its differential diagnosis are discussed.

Adult↗
PubMed1988

Malakoplakia of the parotid gland.

Xanthogranulomatous inflammation is an ubiquitous process that is most commonly observed in the kidney but may be observed in other organs. We report a case of xanthogranulomatous inflammation occurring in an enlarged parotid gland of a 65-year-old man as a result of salivary duct obstruction from sialolithiasis. We discuss the common histologic features and probably common aetiology of several inflammatory xanthograulomatous processes including malakoplakia.

Aged↗
PubMed1988

Squamous metaplasia of the prostate. An immunohistochemical study.

Immunoperoxidase strains for prostate-specific antigen (PSA), prostatic acid phosphatase (PAcP), epithelial membrane antigen (EMA), and cytokeratins (MAK 6 and CK-KES) were performed on 1 case of squamous cell carcinoma of the prostate and on 13 cases of squamous metaplasia of prostatic epithelium in an effort to demonstrate prostatic origin of the neoplastic and metaplastic cells and to differentiate them from primary or metastatic well-differentiated squamous cell carcinoma. The authors found no specific staining of the metaplastic or neoplastic cells for PSA and only focal single cell PAcP positivity in three cases of squamous metaplasia. All cases showed strong staining of surrounding normal glandular epithelium for both antigens. In all but one case, both the metaplastic and glandular epithelium had positive results for MAK 6 and CK-KES. EMA was expressed strongly in ten cases, was weak or variable in two, and had negative results in two cases of squamous metaplasia. In only four cases did the glandular epithelium have positive results for EMA. The remaining cases showed no staining. PSA and PAcP marking, therefore, may not be useful for separating atypical squamous metaplasia from well-differentiated squamous cell carcinoma or even primary prostatic from metastatic squamous cell carcinoma. These findings suggest that although prostatic glandular epithelial cells retain their ability to express some prostate-associated antigens, this ability is greatly reduced, lost, or not developed in cells that undergo metaplasia into squamous cells or that develop into squamous cell carcinoma.

Aged↗
PubMed1988

Prevalence of antibodies to seven viruses in a flock of ewes in Minnesota.

Blood samples were collected from a flock of healthy ewes at a University of Minnesota research station. Sera from these blood samples were tested for antibodies against 7 viruses, using 3 tests (eg, virus-neutralization test for bovine viral diarrhea virus, infectious bovine rhinotracheitis virus, bovine adenovirus type 3, and bovine respiratory syncytial virus; hemagglutination inhibition test for parainfluenza virus type 3; and agar-gel immunodiffusion test for lentivirus of ovine progressive interstitial pneumonia and bluetongue virus). The number of seropositive ewes for each antibody type were 1 of 377 (0.3%) for bovine viral diarrhea virus, 2 of 377 (0.5%) for infectious bovine rhinotracheitis virus, 29 of 378 (7.6%) for bovine adenovirus type 3, 200 of 378 (52.5%) for bovine respiratory syncytial virus, 273 of 373 (71.7%) for parainfluenza virus type 3, and 210 of 379 (55%) for ovine progressive pneumonia virus. All ewes were seronegative for bluetongue virus antibodies.

Adenoviridae↗
PubMed1988

Failed arthrodesis of the spine for severe spondylolisthesis. Salvage by interbody arthrodesis.

Four patients who had had grade-III or grade-IV symptomatic spondylolisthesis and a failed posterior or posterolateral arthrodesis were treated with transperitoneal anterior lumbosacral interbody arthrodesis and fixation with a fibular graft; the procedure was sometimes followed by posterolateral arthrodesis of the spine. The patients were examined ten to twenty-two years after the salvage operation. At follow-up, all had a solid fusion of the fifth lumbar to the first sacral vertebra. No neurological deficits had worsened and no iatrogenic neurological deficits had developed. The slip angle had improved by an average of 23.2 degrees (range, 12 to 35 degrees).

Adolescent↗
PubMed1988

Papillae formation in parathyroid adenoma. A source of possible diagnostic error.

Parathyroid adenomas, the most common cause of hyperparathyroidism, display diverse histologic patterns. The majority of adenomas form solid masses or show nodular, trabecular, and acinar patterns. In a four-year review of data on 103 surgically resected parathyroid adenomas, we encountered only a single case that showed papillae formation. We report this case to illustrate occurrence of this unusual histologic pattern that might create a diagnostic problem.

Aged↗