PubMed Health⌕ Search

Biomedical subjects

W Orr

Publications and source records attributed to W Orr.

At least 19 recordsLinked to original sources
PubMed1992

Proliferative periosteal processes of phalanges: a unitary hypothesis.

A unitary hypothesis is offered to explain the various proliferative processes occurring around the phalanges. In the past, these have been separately designated as proliferative periostitis, bizarre parosteal osteochondromatous proliferation, and turret exostosis. Because the appearances of these entities depend on temporal factors, breaching of the periosteum, and local anatomic features, we suggest a single term, proliferative periosteal processes of phalanges.

Bone Diseases↗
PubMed1989

Genetic analysis of chorion formation in Drosophila melanogaster: I. The effects of one somatic-specific and seven germ-line-specific mutations.

Eight X-linked recessive female sterile mutations, derived from a hybrid dysgenic screen of Drosophila melanogaster and representing eight distinct loci, have been characterized by genetic and ultrastructural analysis. Four have abnormal respiratory appendages, three have essentially normal appendages but show moderate defects in the endochorion, and one mutant, fs(1)ne1a, exhibits major defects in both the endochorion and the respiratory appendages. Germ line clones of all eight mutants were generated using the dominant female sterile technique. Seven of the eight mutations are germ line specific, indicating that, although the eggshell is produced by the follicular cells, germ line functions play a significant role in its elaboration. The mutant that shows major defects, fs(1)ne1a, is somatic line specific, and exerts its effect in the ovary.

Animals↗
PubMed1988

Evaluation of methods for detecting human papillomavirus deoxyribonucleotide sequences in clinical specimens.

Specimens from 26 condylomatous lesions, 24 invasive cancer cells, and 33 cervices, without evidence of the diseases, were tested for the presence of human papillomavirus (HPV) types 6, 11, 16, and 18 by Southern blot hybridization, in situ filter hybridization, or in situ tissue hybridization methods. A total of 89% (23 of 26) of the condylomatous lesions contained HPV DNAs, as determined by one or more of the methods. The positive rates for the detection of HPV DNA in condylomas by the different methods were 82% for Southern blot hybridization, 62% for in situ filter hybridization, and 72% for in situ tissue hybridization. Among the specimens from patients with cancer, HPV DNA was found in 83% (19 of 23) by one or more of the methods. Positive rates of 89 and 70%, respectively, were obtained for cancer lesions tested by the filter in situ and Southern blot hybridization methods; however, only 30% of those lesions were positive by the in situ tissue hybridization method. Thirteen percent of the control cervices were positive for HPV DNA by one or more of the assays. With respect to all disease categories, the methods had comparable sensitivities and specificities, except for the in situ tissue hybridization method, which revealed a specificity of 72% for condylomatous lesions and 30% for invasive cancer cells.

Cervix Uteri↗
PubMed1988

Desmoplastic malignant melanoma. A clinicopathologic study of 14 cases.

Clinical and pathologic details in 14 cases of desmoplastic malignant melanoma were reviewed. The study group included ten men and four women with a median age of 58 years. Anatomic locations such as the head and neck area (four cases), limbs (five cases), and trunk (five cases) were involved with equal frequency. Follow-up information (median period, 4.6 years) was available for 12 patients, of whom four are alive and disease free, six have had local tumor recurrence, and two have died of their disease. Histologically, these lesions consisted of a malignant fibroblastic skin tumor intimately associated with a superficial melanoma (ten cases) or melanocytic dysplasia (four cases) that often extended deeply to the subcutaneous fat. Helpful diagnostic features included the presence of neurotropism, a lymphocytic infiltrate, and unusual patterns of triangular and periadnexal lamellar fibroplasia. Of the immunohistochemical markers employed, antisera to S100 protein and vimentin yielded the most consistent positive results. Immunostaining with NK1/C-3 (antimelanoma monoclonal antibody) was not helpful. Ultrastructural evidence of fibroblastic and schwannian differentiation was seen. We conclude that the altered morphologic melanomas is associated with a relatively favorable prognosis and believe that careful attention to light microscopic detail with immunohistochemical and electron microscopic assistance will elucidate the diagnosis in most cases.

Adolescent↗
PubMed1987

Isolation of mycoplasmas from bovine semen in Northern Ireland.

In a survey of 332 fresh and 137 processed bovine semen samples and 25 preputial washes, mycoplasmas and, or, ureaplasmas were isolated from 46 per cent, 31 per cent and 80 per cent, respectively. Intermittent isolation from different semen collections from the same bull indicated that at least three collections per bull were necessary to determine whether infection was present. When stored processed samples were examined Mycoplasma canadense and M bovigenitalium were isolated from straws taken as long ago as 1975. Addition of lincomycin and spectinomycin to the semen extender eliminated the isolation of mycoplasmas and reduced the rate of isolation of ureaplasmas.

Animals↗
PubMed1985

Halofenate and clofibrate inhibition of pyruvate dehydrogenase from Fusarium culmorum.

Pyruvate dehydrogenase (E1, E.C. 1.2.4.1) was obtained from Fusarium culmorum by ammonium sulfate precipitation. An eight-fold purification was obtained with a specific activity of 13 K units/mg protein. Both halofenate and clofibrate inhibited the enzyme complex non-competitively. The inhibitory effect of halofenate was greater than that of clofibrate being 42% higher at 20 mM concentration compared to the inhibition by clofibrate at 40 mM concentration. Both compounds disorganized the normal cytoplasmic lipids including the emptying of cells in the mycelium suggesting membrane disruption.

Clofibrate↗
PubMed1984

Mutants suppressing in trans chorion gene amplification in Drosophila.

Two recessive female-sterile mutants, K451 and K1214 , disrupt chorion formation by causing underproduction of all major chorion proteins. We present evidence that this effect is due to underaccumulation of the chorion mRNAs and that, in turn, this is caused by a substantial reduction in the level of chorion gene amplification. The mutants are X-linked but located at two sites far from the chorion gene cluster at 7F1 -2; their effect is even more pronounced on the third chromosome chorion gene cluster, and thus the wild type gene must act in trans. The time course of amplification in mutant and wild-type follicles is documented.

Animals↗
PubMed1981

Dose-related effects of flurazepam on human sleep-walking patterns.

Two consecutive nights of flurazepam at each of 15, 26, and 45 mg were compared to placebo in a Latin-square double-blind crossover design using 24 healthy young-adult males. Flurazepam had significant hypnotic effects on objective and subjective measures of efficacy: shorter sleep latency, longer sleep time, and fewer awakenings. It also induced morning sedation along with decrements in cognitive performance. Flurazepam had dose-related impacts on both human and computer-scored EEG-EOG parameters: less stages 3 + 4 and decreased EEG delta, less stage 1 REM and decreased REM density, more stage 2 and increased EEG spindling. Also, EEG alpha and movement artifact were decreased and EEG beta was increased. Only a few of the EEG-EOG variables and none of the subjective indices had cumulative changes on the two drug nights. Stage shifting was unaffected at the two lower doses on the first night but decreased at all three dose levels on the second night; percent stages 3 + 4 was unaffected on the first night but decreased at all dose levels on the second night. The rate of delta waveform activity was also diminished by a greater amount on the second night. This study conclusively established that flurazepam affects the EEG-EOG architecture of sleep on each of the first two nights of administration.

Adult↗
PubMed1980

Adhesive characteristics of tumor cell variants of high and low tumorigenic potential.

A variant subpopulation of C57BL/6 mouse fibrosarcoma cells that had very low tumorigenic potential was isolated from a highly tumorigenic parent fibrosarcoma cell culture. The adhesive characteristics of parent cells and variant cells were compared. The low-tumorigenic variant cells were released from the surfaces of plastic dishes, from protein-coated dishes, or from monolayers of fibroblasts or endothelial cells by protease treatment much more readily than were the parent cells. There was no difference between the variant cells and the parent cells in EDTA sensitivity or sensitivity to mechanical agitation under the conditions used. Also, no difference existed between the variant cells and the parent cells in rates of attachment to the surfaces of plastic dishes or to monolayers of endothelial cells. The variant cells were characterized by high levels of chymotrypsin-like esterase activity (two to three times increased over parent cell levels), but there was only a slight difference between the variant cells and the parent cells in caseinolytic or fibrinolytic activity.

Animals↗
PubMed1979

Chemotactic responses of tumor cells to products of resorbing bone.

To explore possible mechanisms for the metastasis of malignant cells to bone, a model of tumor cell migration was developed, using Walker carcinosarcoma or malignant lymphoma cells. It was found that bone contains a factor that is strongly chemotactic for tumor cells. This factoor is released by a variety of agents that induce resorption of bone.

Animals↗
PubMed1979

Chemotactic factor for tumor cells derived from the C5a fragment of complement component C5.

Previously, we have stablished that the fifth component of complement (C5) serves as an important source of mediators that have locomotory (chemotactic) activity for leukocytes and tumor cells. C5a, a fragment (Mr 11,200) derived from the NH2-terminal portion of the alpha chain of C5, is the major chemotactic peptide for leukocytes. The present studies demonstrate that cleavage of C5a with trypsin generates a derivative peptide that is chemotactic for tumor cells (Walker carcinosarcoma). This fragment has an estimated Mr of 6000 as assessed by gel filtration and does not require the COOH-terminal arginine of C5a, because equivalent amounts of chemotactic activity for tumor cells can be generated from des-Arg-C5a by digestion with trypsin. The C5a-derived chemotactic peptide for tumor cells demonstrates peak activity at approximately 1 pM. These studies emphasize the key role of the C5a region of the C5 molecule in the generation of peptides that affect locomotory responses of cells.

Animals↗
PubMed1979

Cell-associated proteases affect tumour cell migration in vitro.

The in vitro migratory activity of mouse fibrosarcoma cells in medium containing either foetal calf serum or normal human serum was studied. These 2 sera were studied because foetal calf serum contains high levels of protease inhibitor activity while human serum contains much less. The cells migrated actively in medium with foetal calf serum but migration was greatly inhibited in human serum-containing medium. When protease inhibitors such as soybean trypsin inhibitor, lima bean trypsin inhibitor and bovine pancreas trypsin inhibitor were added to human serum-containing medium cell migration was supported almost as effectively as in medium with foetal calf serum. Addition of epsilon-amino-n-caproic acid to human serum or depletion of the plasminogen from human serum did not enable it to support enhanced migration. epsilon-amino-n-caproic acid actually inhibited migration. A variant cell population with elevated levels of caseinolytic activity and elevated levels of activity against the substrate n-acetyl-DL-phenylalanine-beta-naphthyl ester (a substrate specific for chymotrypsin-like enzymes) was isolated from the parent cells. When the variant cells were compared to the parent cells regarding migratory activity in foetal calf serum or human serum-containing medium, the variant cells showed much less activity. Only a few, widely scattered variant cells migrated in the human serum-containing medium. These data suggest that a cell-associated factor interferes with the migration of the cells in medium with human serum. This factor apparently is neutralized in medium sontaining human serum to which protease inhibitors with antitrypsin activity have been added.

Animals↗
PubMed1978

Hydroxymethylglutaryl-coenzyme A reductase. Purification and properties of the enzyme from Fusarium oxysporum.

The hydroxymethylglutaryl-coenzyme A reductase (mevalonate:NADP+ oxidoreductase, EC 1.1.1.34) system in Fusarium oxysporum, a soil inhabiting plant pathogen, has been examined. Two forms of the enzyme catalyzing the conversion of hydroxymethylglutaryl-coenzyme A were obtained in the supernatant after precipitation at 75% (NH4)2SO4 saturation of the soluble culture extract which was previously separated from cell wall, mitochondria and microsomes. The two forms of the enzyme were separated electrophoretically. A third form, contained in the precipitate obtained at 35--75% (NH4)2SO4 saturation of the same extract, was further purified by Sephadex G-50 column chromatography. This purified form moved as a single band in sodium dodecyl sulphate electrophoresis and in immunological tests and has a molecular weight of 11 000. The apparent Michaelis constant for the substrate hydroxymethylglutaryl-coenzyme A is 21 micron at 2 micron NADP. NADPH is a more efficient reductant on a molar basis than NADH for the deacylation of the hydroxymethylglutaryl-coenzyme A substrate. Optimum activity of the enzyme was obtained at pH 7.4 and 37 degrees C. The enzyme demonstrated no cold sensitivity but rather was more stable at 4 degrees C than at 25 degrees C. The protection with dithiothreitol, though minimal compared to other systems, was more effective at the higher temperature.

Fusarium↗