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Biomedical subjects

J Rodgers

Publications and source records attributed to J Rodgers.

At least 91 records · Page 5Linked to original sources
PubMed1990

Production of extra-cellular slime by Staphylococcus epidermidis during stationary phase of growth: its association with adherence to implantable devices.

A method of optimising slime production produced by Staphylococcus epidermis and its quantitative assay was developed, which gave a preliminary indication of its identity and an assessment of the correlation between slime production and adherence of the organism to implants. After inducing vigorous growth in brain heart infusion broth to stationary phase, all nutrients were removed by washing and the organisms resuspended in sterile deionised water with added magnesium. After further incubation the culture was centrifuged and the supernatant reacted with alcian blue in 50 mM magnesium chloride/sodium acetate solution, and the amount of bound dye was measured spectrophotometrically at 620 nm after its resolubilisation using sodium dodecyl sulphate. Large quantities of slime were produced by some, but not all, strains. Preliminary electrophoresis of the slime showed mobility and staining similar to that of the glycosaminoglycans. Adherence was tested by growing strains in wells of tissue culture plates and aspirating the supernatant after incubation. After fixation and staining of adherent growth the amount of bound stain was determined spectrophotometrically after its elution with ethanol. In this series of organisms there was no correlation between the result of tests for adherence or production of extracellular slime, and no correlation between either of these and the clinical source of the organisms.

Bacterial Adhesion↗
PubMed1989

Topical corticosteroid compounding: effects on physicochemical stability and skin penetration rate.

Compounding compatibility studies of four corticosteroid cream products and four commonly added chemicals are presented. Physical alteration, chemical stability, micropreservative challenge status, and in vitro skin penetration were evaluated at ambient conditions for 2 months. The study was designed to generate useful, previously unavailable information to aid dispensing pharmacists and dermatologists.

Administration, Topical↗
PubMed1988

Ras oncogene expression as a prognostic indicator in rectal adenocarcinoma.

In order to investigate the value of ras oncogene expression as a prognostic indicator in rectal adenocarcinoma, we evaluated the level of ras gene protein product (p21) in the available material of 149 consecutive Dukes' B and C specimens resected at our institution between 1965 and 1981. Five year follow-up was available in all patients. Pathology slides and archival paraffin blocks were retrieved for confirmation of the original diagnosis, study of histopathological features, and measurement of p21 content. P21 titers were obtained using the RAP-5 monoclonal antibody in a semiquantitative immunohistochemical assay. Titer was expressed as the highest dilution of antibody giving definitive staining using the avidin-biotin peroxidase method. The analysis indicated that the group of tumors with high (greater than or equal to 1:40,000) p21 titers had a worse 5-year survival (43.9 versus 64.3%, P less than 0.02), higher incidence of distant metastases (51.8 versus 23.2%, P less than 0.001), and more advanced Dukes' stage (53.7 versus 35.7% incidence of Dukes' C stage, P less than 0.04) than tumors with low (less than 1:40,000) titers. Multivariate analysis also demonstrated that the influence of the level of ras gene protein product on survival was independent of Dukes' stage. We conclude that detection of high levels of ras oncogene protein product indicates a group of tumors with a more aggressive behavior, characterized by a higher percentage of distant recurrences and worse prognosis. These findings suggest that measurement of p21 may become clinically important in identifying patients at high risk of recurrent disease.

Adenocarcinoma↗
PubMed1988

Intraoperative radiation therapy of hepatic metastases: technical aspects and report of a pilot study.

Surgical resection of hepatic metastases offers long-term survival, and possible cure, for selected patients with colorectal carcinoma. Fifty percent of patients considered candidates for resection are found to have disease confined to the liver. The resections necessary are often more extensive than predicted preoperatively, which provides an opportunity for innovative approaches using radiation therapy. The intraoperative radiation therapy technique presented here offers the ability to control multiple metastatic deposits in patients not deemed resectable. This is achieved using remote afterloading interstitial (Ir-192) radiation therapy to deliver tumoricidal radiation doses to limited volumes within the liver. The technique was used to treat 11 patients in a pilot study, delivering radiation doses of 20 Gy to the periphery of predetermined target volumes in a single treatment. The number of metastatic deposits treated ranged from 2 to 11 separate tumors with maximum diameters from 3 to 9 cm (median 6 cm). Hospitalizations were from 6 to 23 days (median 8) with only one patient experiencing a surgically related complication (wound dehiscence and pneumonia). There were no radiation related complications on follow-up to 18 months. Biopsies of two treated sites in a patient undergoing reoperation confirmed control of tumors by this procedure. This technique is offered as a standby procedure to patients undergoing exploration for hepatic resection at our institution.

Aged↗
PubMed1987

Ras oncogene p21 levels parallel malignant potential of different human colonic benign conditions.

Ras oncogenes are a specific family of genes believed to play a role in malignant transformation and tumor growth in humans. To gain a better understanding of the role these oncogenes may play in malignant transformation, we evaluated the levels of a ras gene protein product (p21) in formaldehyde-fixed, paraffin-embedded specimens of normal human colonic mucosa, hyperplastic polyps, tubular adenomas, villous adenomas, and epithelium from a patient with ulcerative colitis. The p21 protein content was measured using the RAP-5 monoclonal antibody in a semiquantitative immunohistochemical assay. The titer value was expressed as the highest dilution of antibody giving definite staining using the avidin-biotin peroxidase method. Differences in p21 titer values among all classes of polyps were significant (hyperplastic polyps values were less than tubular adenomas values, which were less than villous adenoma values). The p21 titers obtained from ulcerative colitis specimens were similar to those obtained from villous adenomas. We conclude that the levels of ras oncogene protein product increase with the malignant potential of benign human colonic conditions. These findings suggest that the ras oncogene protein product may play an important role in the malignant transformation of benign lesions of the human colon. If these findings are confirmed, as technology progresses to allow molecular probes to measure gene products in biopsy specimens, high-risk patients could be monitored and treated before actual malignant transformation occurs.

Adenoma↗
PubMed1987

Dose-volume and complication in interstitial implants for breast carcinoma.

A common radiotherapeutic technique for treating breast cancer is the combination of external beam radiation with an interstitial iridium-192 boost. When smaller tumors (T1 and T2) are treated using this technique, the soft tissue complication rate is small. However, with treatment of more advanced stages of disease, where large volumes of breast tissue must be treated to high radiation doses, the incidence of complication increases. This paper investigates the dose and volume relationships for breast tissue treated by interstitial technique and correlates this to the risk of soft tissue radiation injury. A method of analysis of interstitial radiation implants suitable for intra- or inter-institutional clinical evaluations is offered. The records of 111 patients treated at Georgetown University Hospital, were retrospectively analyzed and the five who had experienced radiation-related complications were compared to 51 randomly selected patients experiencing no complications. The volumes of tissue enclosed by selected isodose surfaces were calculated and used to determine a relationship between these dose-volumes and the probability of complication. The mean volume at specified dose levels between 10 Gy and 50 Gy was significantly higher (p less than .05) for the patients developing complications than those in whom no complications were seen. Using the 20 Gy isodose surface as defining our usual treated volume, a complication probability versus dose-volume curve was developed using a linear logistic model. The curve fitted the data closely (p less than .006) suggesting that, for our cases, the calculated treatment volume (within the 20 Gy isodose surface) can be used to effectively separate patients into groups that have different probabilities of developing complications. We propose this method as a basis for specification of dose and volume which can be used for clinical risk assessment, and for intra- and inter-institutional comparison.

Brachytherapy↗
PubMed1987

Acute health care costs for the aged Medicare population: overview and policy options.

Despite its seeming largesse, Medicare has always been a cost-sharing program. The potential costs borne by beneficiaries can be substantial, leading to more than 70 percent seeking protection through supplementary private insurance. Others risk payment out of pocket, and fewer rely on Medicaid. Actual costs incurred by each group of Medicare beneficiaries are examined and seen to have significant and inequitable impacts. Current Medicare policies are often poorly designed or irrelevant. Future responses will have to address both taxation and copayment while weighing concerns for individual financial hardship against possible overuse of services.

Acute Disease↗
PubMed1985

Medicaid program characteristics: effects on health care expenditures and utilization.

Relationships between State Medicaid program characteristics and program outputs are analyzed in this statistical report, using 1980 cross-sectional data from a variety of sources. The year 1980 furnishes a baseline against which program changes following the Omnibus Budget Reconciliation Act of 1981 and the 1982 economic recession can be evaluated. Utilization and expenditures are modeled separately for each aid category and each major service category. This use of multiple models allows for measurement of the effect of program controls that might not appear in models of total utilization and expenditures.

Adult↗
PubMed1983

Cicatricial ectropion due to essential skin shrinkage: treatment with rotational upper-lid pedicle flaps.

Ectropion is sometimes due to a shortage of skin of the lower lid (cicatricial) and may result from previous surgery, trauma, burns, skin diseases etc. Excessive exposure to the sun has also been incriminated. Vertical traction lines in the skin of the lower lid, accentuated by gazing up or by opening the mouth, suggest this condition. This paper describes the use of pedicle skin flaps rotated from the upper lid to treat cicatricial ectropion occurring in the absence of any predisposing factor and not responding to conservative treatment--that is, due to essential skin shrinkage. All 10 patients had an improved appearance, and epiphora persisted in only 1 patient, who subsequently underwent a punctum-enlarging procedure. In an 11th patient there was insufficient redundant upper-lid skin, so a free skin graft was used instead.

Cicatrix↗
PubMed1982

Dermoid tumor involving the lacrimal drainage pathway: a case report.

Dermoid tumors of the orbit frequently are encountered in children and young adults. We describe an interesting case of an orbital dermoid which involved the lacrimal excretory system in a 27-year-old female. We emphasize the importance of a preoperative assessment in planning the surgical approach and anticipating the possible surgical complications. The role of the canaliculo-dacryocystorhinostomy (CDCR) in the management of such a patient is emphasized.

Adult↗
PubMed1981

Shock trauma!

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Emergency Medical Services↗