Biomedical subjects

J R Davis

Publications and source records attributed to J R Davis.

348 records · Page 20Linked to original sources

PubMedDate not supplied

The X-linked lymphoproliferative disease: from autopsy toward cloning the gene 1975-1990.

Although X-linked lymphoproliferative disease (XLP) is rare (1-2 males per 1 x 10(6)), it serves as a model for discerning diverse diseases caused by Epstein-Barr virus (EBV) ranging from agammaglobulinemia to fatal infectious mononucleosis following infection with the virus. The study of patients with XLP has also paved the way to understanding how EBV induce diseases in children with primary immunodeficiency diseases, organ transplant recipients, and those with acquired immunodeficiency syndrome. This review is dedicated to the memory of Gordon Vawter, M.D., who generously provided insights into the causes of pathogenesis of immune deficiency and lymphoproliferative disorders.

Autopsy↗

PubMedDate not supplied

Reticuloendotheliosis virus (REV) long terminal repeats incorporated in the genomes of commercial fowl poxvirus vaccines and pigeon poxviruses without indication of the presence of infectious REV.

Because of reticuloendotheliosis virus (REV) contamination in commercial poultry vaccines, polymerase chain reaction (PCR) assays have been described to increase the sensitivity of biological assays used to detect REV in vaccines. The PCR assay designed to amplify the long terminal repeat (LTR) region of REV identified REV LTRs in many of the commercial fowl poxvirus (FPV) vaccines evaluated. These commercial vaccines were not thought to be contaminated with replicating REV because of the lack of REV outbreaks, the lack of in vitro amplification, and lack of a serologic response to REV. As previously described, the FPV S vaccine strain is known to carry infectious integrated proviral REV, whereas FPV M vaccine strain and its derivatives carry integrated LTRs or remnants of REV proviral DNA inserted into the FPV genome. Another PCR assay designed to amplify the envelope gene of REV was used to verify that the envelope proviral gene was not present in REV LTR PCR-positive samples. Southern blot analysis with REV LTR probes hybridized to the 9-kb EcoRI genomic fragment of all FPV and pigeon poxviruses evaluated, whereas the envelope probe did not hybridize to any poxvirus genome. Sequence analysis of the 9-kb EcoRI fragment indicated that an integrated REV LTR exists in the 9-kb EcoRI of some poxvirus genomes. A new PCR assay designed to amplify integrated REV LTRs in the 9-kb EcoRI fragment identified complete and incomplete integrated REV LTRs in all FPV and pigeon poxvirus genomes evaluated.

Animals↗

PubMedDate not supplied

Enalapril and verapamil in the treatment of isolated systolic hypertension in the elderly.

A prospective, investigator-blinded, randomized study was conducted to compare the efficacy and tolerability of enalapril and verapamil in the treatment of isolated systolic hypertension in elderly patients. Of the 115 patients who completed the study, 58 received enalapril and 57 verapamil. The goal of treatment was a systolic blood pressure < 160 mmHg and a reduction of at least 20 mmHg below baseline. The initial daily dose of enalapril was 5 mg, and of verapamil 240 mg. The dosage was titrated upward until the goal blood pressure was achieved. At the end of the titration period, systolic and diastolic blood pressures were significantly decreased (P < 0.001) in both patient groups. Blood pressure remained significantly decreased (P < 0.001) in both groups during the 8-week maintenance treatment period. There were no significant differences between groups. Two patients in the enalapril group and nine patients in the verapamil group were withdrawn from the study because of adverse effects. The results of this study demonstrate that enalapril and verapamil are well tolerated and effective in the treatment of isolated systolic hypertension in the elderly.

Aged↗

PubMedDate not supplied

Cytogenetic and clinical assessment of six patients with erythroleukemia.

We report the detailed karyotypic analysis and clinical features of six patients with erythroleukemia (EL). Five of six patients studied displayed substantial numeric and structural chromosome abnormalities. The most common alterations in these patients were monosomy for chromosome 7 and 16. All five patients displaying chromosomal abnormalities presented with 100 percent abnormal metaphases in their bone marrow at the time of initial diagnosis. The remaining patient was studied only during remission and had a normal diploid karyotype in all marrow cells analyzed. No patient in this study had either a Ph1 -chromosome (characteristic of CML), or translocations of chromosome #8-#21 (characteristic of AML-M2). Clinically, all but one patient had a brief history; the exception having had polycythemia rubra vera for 18 years prior to the onset of EL. All patients were treated with current Southwest Oncology Group (SWOG) protocols using cytosine arabinoside and anthracycline combinations. Three of five patients entered complete remission. However, remission durations were short (approximately six months) and median survival just over one year. Cytogenetic analysis of three patients in hematologic remission revealed persistence of chromosomal alterations. It is suggested that such remissions be reclassified as partial rather than complete based upon the cytogenetic information.

Adult↗

PubMedDate not supplied

Value of duplicate smears in cervical cytology.

The cytologic accuracy, sources of error and value of duplicate samples were studied in 87 women simultaneously biopsied for cervical intraepithelial neoplasia. Separately evaluated by two laboratories, correlation with biopsy was 70% for the first cytology and 67% for the second. Discrepant cytologies were reciprocally reviewed in error analysis. The sources of error were cytologic sampling (10.9%), evaluation (5.8%) and both (4.0%). Attention is directed to the high proportion of cases (15%) in which sampling error was a factor; awareness of this observation is necessary in patient management. The duplicate second cytology was of substantial value in 7% of the cases and helpful in an additional 3.5%; both figures are lower than in recent reports. If errors in evaluation or evaluation sampling are held to a 10% level, routine duplicate studies may not be justified.

Carcinoma in Situ↗

PubMedDate not supplied

Effects of enhanced calling efforts on response rates, estimates of health behavior, and costs in a telephone health survey using random-digit dialing.

Public health researchers frequently rely on random-digit dialing (RDD) telephone surveys in monitoring trends in health behavior and evaluating health promotion interventions. RDD response rates have declined during the past decade, and cost-effective methods to increase response rates are needed. The authors evaluated two levels of enhanced calling efforts in an RDD survey of cancer-related health behavior in the State of Washington. The first level of enhanced calling effort was 1 month after 11 original calling attempts to a household, when the authors attempted up to 11 recalls. The second level was 6 months after the first answered call, when the authors recalled those persons who could not be interviewed. Enhanced calling efforts increased the overall survey response rate by 11 percent. Nine percentage points of the increase were attributable to call backs. There were demographic differences among the participants reached at different levels of calling effort, but no consistent associations of level of calling effort with health behavior related to alcohol use, smoking, diet, or health screening. Marginal costs for interviews completed with enhanced calling efforts were about 50 percent higher than costs for interviews reached in the first 11 calls. The authors concluded that enhanced calling efforts may be justified, because they increase confidence in the generalizability of survey results. However, the authors found very little change in survey results by including interviews from persons who were difficult to reach and to interview.

Adolescent↗