PubMed Health⌕ Search

Biomedical subjects

R J Shannon

Publications and source records attributed to R J Shannon.

7 recordsLinked to original sources
PubMed2001

GRIM-19, a cell death regulatory gene product, is a subunit of bovine mitochondrial NADH:ubiquinone oxidoreductase (complex I).

The sequences of 42 subunits of NADH:ubiquinone oxidoreductase (complex I) from bovine heart mitochondria have been described previously. Seven are encoded by mitochondrial DNA, whereas the remaining 35 are nuclear gene products imported into the organelle from the cytoplasm. An additional protein, which does not correspond to any previously known subunit of the complex I assembly, has now been detected. Denaturing gels of subcomplex Ilambda, the hydrophilic arm of complex I, clearly show a hitherto unidentified band, which was digested with trypsin and subjected to mass-spectrometric analysis to provide several peptide sequences, used in cDNA cloning and sequencing. Measurement of the intact protein mass indicated that the N terminus is acetylated. The new complex I subunit (B16.6) is the bovine homolog of GRIM-19, the product of a cell death regulatory gene induced by interferon-beta and retinoic acid, thus providing a new link between the mitochondrion and its electron-transport chain and apoptotic cell death.

Amino Acid Sequence↗
PubMed1997

Hyalinizing spindle cell tumor with giant rosettes: a distinctive tumor closely resembling low-grade fibromyxoid sarcoma.

We report the findings of 19 cases of a previously undescribed spindle cell tumor of soft tissues that resembles a low-grade fibromyxoid sarcoma but contains distinctive rosettelike structures. The tumors occurred principally as a painless, slowly growing, deeply situated mass of the proximal extremities in young to middle-aged adults (age range 14-65 years; mean 38). Although grossly circumscribed, the tumors had infiltrative borders microscopically and were composed of bland spindled cells situated in a hyalinized to myxoid stroma. The most characteristic feature of the tumor was scattered large rosettelike structures that often merged with serpinginous areas of dense hyalinization. The rosettes consisted of a central collagen core surrounded by a rim of rounded cells morphologically and immunophenotypically different from the cells of the spindled stroma. These cells expressed a number of antigens, including S-100 protein, neuron-specific enolase, and leu 22, in contrast to the stroma, which usually lacked these antigens. Of the 12 patients with available follow-up information, one patient treated with simple excision clinically developed local recurrence of the tumor 20 months after initial biopsy. No other recurrences were reported during the limited follow-up period, and no patient developed metastatic disease. However, the favorable prognosis of the patients in our series to date may relate to the limited follow-up period (approximately 3 years), as well as initial treatment by wide excision in nearly half of the patients. We regard the hyalinizing spindle cell tumor with giant rosettes as a distinctive type of low-grade fibroblastic tumor that with time may prove to behave similar to a low-grade fibromyxoid sarcoma and, hence, to represent an unusual variant thereof.

Actins↗
PubMed1978

Symptomatic bacterial urinary tract infections in men: limitations of quantitative urine cultures.

Occasionally, physicians have discarded the diagnosis of acute symptomatic bacterial urinary tract infection when the urine coutn failed to approach or exceed 100,000 organisms per ml. Previous studies done in women have established the fact that sole reliance cannot be placed on this value to exclude the diagnosis of symptomatic bacterial urinary tract infection. A retrospective analysis of the charts of male patients, with an unequivocal diagnosis of symptomatic bacterial urinary tract infection, demonstrates the limitations of the urine colony count as a diagnostic test in men.

Aged↗
PubMedDate not supplied

Effect of calcium alginate dressings on partial-thickness wounds in swine.

The epithelization of partial-thickness wounds (PTW) has been shown to be enhanced with the use of moisture-retentive dressings (MRD), and not with nonmoisture-retentive dressings (NMRD) like gauze. This study was designed to explore this effect using two different alginate products with and without MRDs. We evaluated these alginate dressings under a polyurethane film dressing (FMRD) and under an NMRD gauze. They were compared to hydrocolloid moisture-retentive dressings (HMRD). Twelve PTW measuring 22 x 22 x 0.5 mm were made on the dorsum of six swine with a Castroviejo dermatome. Return of the epithelial barrier function was measured with an EP1 ServoMed evaporimeter. On postoperative day 4, the first alginate product under the NMRD and under the FMRD had a significantly slower healing rate than the HMRDs. By postoperative day 7, the second alginate product under the NMRD had a poorer rate of epidermal wound healing than the HMRD. Our results indicate that these alginate products have a satisfactory partial-thickness wound healing capability when used under MRDs. When used under MRDs, the return of the epithelial barrier function is delayed, indicating that these dressings should not be used on dry wounds or under gauze dressings.

Alginates↗