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Biomedical subjects

R Gray

Publications and source records attributed to R Gray.

At least 271 records · Page 15Linked to original sources
PubMed1990

Computed tomography and lateral ventricular asymmetry: clinical and brain structural correlates.

Asymmetry of the ventricles of the brain without an obvious cause is a common and intriguing radiologic finding. To understand this phenomenon better the authors conducted a 24-month study to compare clinical and structural manifestations of two groups of patients who had undergone head computed tomography (CT): group A comprised 249 patients with asymmetry of the lateral ventricles of the brain without space-occupying lesions, intracranial bleeding, recent infarction or trauma and group B comprised 266 patients with the above exclusion criteria but without ventricular asymmetry. The degree of ventricular asymmetry was classified as mild, moderate or severe, according to the ratio of the larger frontal horn diameter to the smaller one. The incidence of lateral ventricular asymmetry was 5.3%. The following clinical manifestations were more frequently present in group A: headaches (p = 0.002), seizures (p = 0.007) and positive human immunodeficiency virus (HIV) status (p = 0.02). Transient ischemic attacks were more prevalent in group B (p = 0.009). Independent predictors of headache were: younger age (p less than 0.001) and the degree of ventricular asymmetry (p = 0.02). Predictors of seizures were: younger age (p less than 0.001), ventricular asymmetry (p = 0.004) and the absence of septal deviation (p = 0.009). In group A, predictors of a higher degree of asymmetry were septal deviation (p less than 0.001) and older age (p = 0.008). The authors conclude that asymmetry of the lateral ventricles of the brain is a relatively common CT finding that has important clinical and brain structural correlates and deserves more attention in the field of imaging.

Adult↗
PubMed1990

Legionella lung cavitation.

Pneumonia due to Legionella has been identified in a small percentage of patients suffering from acquired immune deficiency syndrome (AIDS), with and without coexisting Pneumocystis carinii pneumonia. On chest radiographs Legionella typically produces focal parenchymal opacities and confluent lobar consolidation. The authors describe a case of cavitating Legionella pneumonia, which occurred in a 38-year-old man who had AIDS. The main differential diagnoses are an unusual presentation of P. carinii pneumonia and fungal infection. The authors also emphasize the increasing recognition of bacterial pneumonia with atypical radiologic features in AIDS patients.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Efficacy of adjuvant chemotherapy in high-risk node-negative breast cancer. An intergroup study.

We randomly assigned 536 women who had undergone either a modified radical mastectomy or a total mastectomy with low axillary-node dissection for potentially curable breast carcinoma to receive adjuvant chemotherapy or no-treatment observation. The patients were considered at high risk for recurrence because they had either an estrogen-receptor-negative tumor of any size or an estrogen-receptor-positive tumor at least 3 cm in diameter with no histopathological evidence of axillary-node involvement. The chemotherapy consisted of six four-week cycles of cyclophosphamide (100 mg per square meter of body-surface area orally on days 1 through 14), methotrexate (40 mg per square meter intravenously on days 1 and 8), fluorouracil (600 mg per square meter intravenously on days 1 and 8), and prednisone (40 mg per square meter orally on days 1 through 14). Treatments were balanced with respect to patients' characteristics. The analysis included 406 eligible patients who were entered in the study before October 1, 1987. The overall disease-free survival among patients treated with the four-drug regimen was 84 percent, as compared with 69 percent for the control group, at a median follow-up of three years (P = 0.0001). A treatment benefit was also observed in premenopausal and postmenopausal patients as well as in patients with estrogen-receptor-positive or with estrogen-receptor-negative tumors. Severe or life-threatening hematologic toxicity was encountered in 33 percent of the treated patients, with one death. Our results indicate that adjuvant chemotherapy with six cycles of cyclophosphamide, methotrexate, fluorouracil, and prednisone is effective in improving three-year disease-free survival among high-risk patients with axillary-node-negative, operable breast cancer. An analysis of the effect of treatment on survival awaits a longer follow-up.

Adult↗
PubMed1989

Seasonal abundance of Musca vitripennis (Diptera: Muscidae) on Terceira, Azores.

Data from pyramid and electrocuting traps as well as records of Musca vitripennis Meigen interceptions on cargo aircraft indicate that M. vitripennis adults reach peak abundance on Lajes Field, Azores, from mid-August through mid-October. Disinsection of military cargo aircraft and other quarantine actions to prevent accidental movement of flies from the Azores to airports in the United States are required during this period.

Aircraft↗
PubMed1989

AML associated with previous cytotoxic therapy, MDS or myeloproliferative disorders: results from the MRC's 9th AML trial.

The outcome of treatment with standard first line therapy of 66 patients with acute myeloid leukaemia (AML) secondary to preceding chemotherapy (Group 1), a myelodysplastic state (Group 2) or a myeloproliferative disorder (Group 3) was analysed in relation to the preceding disorder, the cytogenetic pattern where available, and the cytology and cytochemistry of blood and bone marrow. The complete remission (CR) rate for the secondary AMLs was 36% (24/66), with 24% (16/66) dying in the induction period and 39% (26/66) having resistant disease. The CR rate was 25% (5/20) for Group 1, 42% (15/36) for Group 2, and 40% (4/10) for Group 3. Even after allowance for the generally older age of the secondary AML patients, they still had a significantly poorer CR rate than the de novo AMLs (P = 0.0004). The lower CR rate was chiefly due to resistant disease. Despite this, overall survival was not significantly worse for the secondary AML patients (P = 0.15). For the 36% that achieved remission, remission duration appeared similar to that of de novo cases. Of 62 cases with adequate cytology, 38 (61%) had evidence of erythroid and/or megakaryocytic dysplasia with a CR rate of 32% (12/38). The CR rate of these multineage leukaemias was not significantly different from that of the 24 (39%) who showed granulocyte/monocyte precursor involvement only, 42% (10) of whom achieved CR. The presence of features of differentiation within blast cells such as Auer rods or sudanophilia (greater than 50% positive blasts) was associated with a higher remission rate 47% (18/38) than that of poorly differentiated cases 17% (3/18) (P = 0.04) and thus appeared to be a more important determinant of CR achievement than was lineage involvement. Cases with a normal karyotype had a 33% (7/21) CR rate, while those with chromosomal abnormalities had a 37% (9/24) CR rate. Only 12 of the 45 cases with adequate cytogenetic analysis showed deletions or monosomies involving chromosomes 5 or 7, and seven of these were in Group 1.

Adolescent↗
PubMed1989

Non-allelic mutations in X-linked retinitis pigmentosa.

Using RFLP studies, the disease locus in two X-linked retinitis pigmentosa families was found to be centromeric to DXS7 in one family and telomeric to DXS7 in another, suggesting non-allelic heterogeneity.

Blotting, Southern↗
PubMed1989

Linkage heterogeneity between X-linked retinitis pigmentosa and a map of 10 RFLP loci.

In nine families in which X-linked retinitis pigmentosa (XLRP) is segregating, the lod scores of XLRP in a map of 10 RFLP loci were obtained by multipoint linkage analysis. The XLRP locus was located telomeric to DXS7 in seven of the families and centromeric to DXS7 in two of the families. Under the hypothesis of two XLRP loci, a heterogeneity (admixture) test was performed, providing significant evidence of heterogeneity in XLRP (P less than .01). No correlation was detected between the clinical manifestations of XLRP and the two different disease loci.

Chromosome Mapping↗
PubMed1989

Enzyme immunoassay system for panel testing.

An immunoassay system based on enzyme immunoassay technology has been developed for quantitative panel testing. The system includes test card disposables, reagents, and an instrument. Patients' samples are processed semiautomatically in the instrument with minimum user intervention. The test card has multiple test areas at individual locations on a membrane solid phase so that simultaneous determinations from a single specimen are possible. Each panel also includes positive and negative reagent procedural controls. Factory-determined calibration curves for each analyte are provided in barcode form with each test kit. The reagents include a specimen dilution buffer, enzyme conjugate, and precipitogenic substrate. Up to 10 test cards at a time can be processed in random-access and continuous-access modes, with automated agitation of sample and reagents over the solid phase, temperature-controlled incubation, and membrane washing and reading, data reduction, and printout of results. The optical reader measures diffuse reflectance and features source intensity and wavelength compensation.

Chemistry, Clinical↗
PubMed1988

Randomised trial of prophylactic daily aspirin in British male doctors.

A six year randomised trial was conducted among 5139 apparently healthy male doctors to see whether 500 mg aspirin daily would reduce the incidence of and mortality from stroke, myocardial infarction, or other vascular conditions. Though total mortality was 10% lower in the treated than control group, this difference was not statistically significant and chiefly involved diseases other than stroke or myocardial infarction. Likewise, there was no significant difference in the incidence of non-fatal myocardial infarction or stroke--indeed, disabling strokes were somewhat commoner among those allocated aspirin. The lower confidence limit for the effect of aspirin on non-fatal stroke or myocardial infarction, however, was a substantial 25% reduction. Migraine and certain types of musculoskeletal pain were reported significantly less often in the treated than control group, but as the control group was not given a placebo the relevance of these findings was difficult to assess. There was no apparent reduction in the incidence of cataract in the treated group. The lack of any apparent reduction in disabling stroke or vascular death contrasts with the established value of antiplatelet treatment after occlusive vascular disease.

Aspirin↗
PubMed1988

Efficacy of esmolol in the treatment and transfer of patients with supraventricular tachyarrhythmias to alternate oral antiarrhythmic agents.

The efficacy and safety of esmolol, a titratable intravenous beta-adrenergic blocking agent with a short elimination half-life (t 1/2 = 9.0 min) was evaluated in a multicenter open-label study for the treatment of supraventricular tachyarrhythmias (heart rate greater than 100 bpm). The study also investigated the feasibility of transferring patients from esmolol to alternate oral antiarrhythmic agents without loss of therapeutic response. Of the 113 patients studied, 95 (84%) achieved therapeutic response (reduction in heart rate of 15% or more or conversion to sinus rhythm). Most of these patients (93%) achieved the therapeutic response at esmolol doses of 200 micrograms/kg/min or lower. Transfer from esmolol to an oral antiarrhythmic agent(s) was studied in 76 patients. Alternate antiarrhythmic agents used in this study were digoxin (N = 25), propranolol (N = 21), verapamil (N = 10), metoprolol (N = 11), quinidine (N = 2), and a combination of two antiarrhythmic agents (N = 7). Sixty-seven (88%) patients were successfully transferred to oral antiarrhythmic agents without loss of the therapeutic response obtained with esmolol. The most frequent adverse effect observed during the study was hypotension, which resolved quickly (16 +/- 14 min) either by decreasing the dose or by discontinuation of esmolol infusion. This study supports previous observations concerning the safety and efficacy of esmolol in the treatment of supraventricular tachyarrhythmias. Furthermore, it demonstrates that the majority of patients successfully treated with esmolol can be safely and effectively transferred to oral therapy with alternate antiarrhythmic agents.

Adrenergic beta-Antagonists↗
PubMed1988

Use-effectiveness of the ovulation method initiated during postpartum breastfeeding.

Between April 1981 to March 1984, 419 urban middle class postpartum women entered the Natural Family Planning (NFP) program of the Pontificia Universidad Catolica de Chile. This NFP program teaches the Ovulation Method (Billings). Only 1.9% of the women did not learn how to recognize the mucus pattern of fertility awareness. The sample of 378 women who were practicing the method to avoid a pregnancy completed 4,935 months of use of the OM. The cumulative life table unplanned pregnancy rate at the 12th postpartum month was 11.1 +/- 1.9 and the Pearl Rate was 12.1 per 100 woman-years. The Pearl Rate calculation of method-related failure was only 2.1 pregnancies per 100 woman-years. The breastfeeding group showed a significantly lower rate of unplanned pregnancies than the nonbreastfeeding group and there was no significant increase in unplanned pregnancy at the time of menstruation among previously amenorrheic women as compared to later intervals. The protection against unplanned pregnancy shown in this study should be viewed as the combination of two factors: breastfeeding and the Ovulation Method (OM) of NFP.

Adult↗
PubMed1988

Identification of a subgroup of patients with breast cancer and histologically positive axillary nodes receiving adjuvant chemotherapy who may benefit from postoperative radiotherapy.

Risk factors for isolated local-regional (LR) recurrence following mastectomy for breast cancer were analyzed in a review of 627 women entered into Eastern Cooperative Oncology Group (ECOG) adjuvant chemotherapy trials between 1978 and 1982. Premenopausal patients were randomized to cyclophosphamide, methotrexate, and fluorouracil (5-FU) (CMF), cyclophosphamide, methotrexate, 5-FU, and prednisone (CMFP), or cyclophosphamide, methotrexate, 5-FU, prednisone, and tamoxifen (CMFPT). Postmenopausal patients were randomized to observation, CMFP, or CMFPT. Median follow-up time was 4.5 years. At 3 years, 225 patients relapsed and in 70 (31% of failures, 11% of all patients) the initial site was LR without distant metastases. In a multivariate analysis, the risk of an isolated LR recurrence significantly correlated with the number of positive axillary nodes, the primary tumor size, the presence of tumor necrosis, and the number of axillary nodes examined. Factors that significantly discriminated between an isolated LR recurrence and distant metastasis were the number of positive nodes and primary tumor size. Patients with four to seven positive nodes or tumor size greater than or equal to 5 cm had a chance of developing an isolated LR recurrence almost equal to the risk of distant metastases. These findings suggest a potential for improved survival in this subset of patients with the addition of postmastectomy radiation to chemotherapy, and continue to emphasize the presence of a group of patients at high risk for isolated LR recurrence despite adjuvant chemotherapy.

Adult↗