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Biomedical subjects

G Rogers

Publications and source records attributed to G Rogers.

88 records · Page 5Linked to original sources
PubMed1980

New vectorcardiographic criteria for diagnosing right ventricular hypertrophy in mitral stenosis: comparison with electrocardiographic criteria.

Frank-lead vectorcardiograms (VCGs) and standard 12-lead electrocardiograms (ECGs) were analyzed to develop simple, linear, quantitative criteria for the diagnosis of right ventricular hypertrophy (RVH). The study subjects included a population with a definite RVH (84 patients with mitral stenosis proved by cardiac catheterization and pulmonary arterial systolic pressure > 40 mm Hg) and a population with minimal likelihood of RVH (173 young, healthy volunteers and 151 normal subjects proved by cardiac catheterization). VCGs were evaluated to identify criteria that provided maximum sensitivity and at least a 95% specificity: the maximum QRS magnitude had to be < 1.8 mV and either (1) the amplitude at -45 degrees (transverse plane) had to be < 0.3 mV or (2) the maximum anterior amplitude plus the maximum rightward amplitude minus the amplitude at -45 degrees must be greater than or equal to 0.5 mV. Application of these criteria achieved 60% (50 of 84) sensitivity in patients with RVH, similar to that for previous VCG criteria but significantly better (p < 0.01) than the best sensitivity with any ECG criteria (27%, 23 of 84). The specificity of the proposed criteria was 96% (310 of 324), significantly better (p < 0.001) than the 78% specificity (252 of 324) of existing VCG criteria. Thus, linear measurements of the QRS complex displayed on the VCG identify 60% of patients with moderate-to-severe RVH and falsely indicate RVH in only 4% of normal subjects.

Adult↗
PubMed1979

Processing in vitro of placental peptide hormones by smooth microsomes.

Rough and smooth microsomes were prepared from ascites tumor cells, rat liver, and bovine adrenal cortex. Proteolytic removal of the signal peptide in pre-placental lactogen and asparagine-linked glycosylation of the alpha subunit of chorionic gonadotropin by these fractions were examined in mRNA-dependent lysates from ascites cells. Both processing steps were performed by smooth microsomes, which was unexpected because it has been presumed that only rough microsomes contain components for ribosomal binding. Thus smooth microsomes are apparently capable of interacting with polysomes bearing secretory nascent chains, and cleavage and asparagine-linked glycosylation activities are present in both rough and smooth endoplasmic reticulum.

Adrenal Cortex↗
PubMed1977

Management factors and grass tetany in dairy cattle.

The relationship between intensity of production and the occurrence of hypomagnesaemia and grass tetany in dairy cattle was investigated from 1966-1970 at the Ellinbank Dairy Research Station, Warragul, Victoria. Hypomagnesaemia and/or grass tetany occurred in cows grazing at both high (3.2 cows/hectare) and low (2.2 cows/hectare) stocking rates over the four-year period. Pasture Mg concentrations remained relatively high (0.2% dry matter) throughout this period, except in the low stocking rate pastures in one year, 1967. It is concluded that hypomagnesaemia and grass tetany was precipitated by a combination of low dry matter intake in winter and the effects of a gradual increase of K concentration in autumn and winter pastures, following the heavy application of K fertilizer. Under these conditions, MgO supplementation was inadequate to prevent grass tetany occurring in some animals.

Animal Husbandry↗
PubMed1977

An integrated approach to tuberculosis care in the Commonwealth of Pennsylvania.

A significant economization of taxpayers resources (+5.5 million per year) is the result of a major restructuring of the tuberculosis control program in the Commonwealth of Pennsylvania. Concomitantly improved patient management has accelerated the decline in the incidence of tuberculosis while maintaining recommended federal performance standards. The reasons for the success in obtaining this high degree of efficiency are discussed.

Aftercare↗
PubMed1976

Endoscopic complications. Results of the 1974 American Society for Gastrointestinal Endoscopy Survey.

Esophagogastroduodenoscopy (211,410 examinations) had a complication rate of 1.3/1,000 cases. Duodenoscopy with cannulation was performed 3,884 times and had a complication rate of 21.6/1,000 examinations. Diagnostic coloscopy (25,298 examinations) had a complication rate of 3.4/1,000. Polypectomies during coloscopy (6,124 cases) had a complication rate of 23.3/1,000 cases. Esophageal dilations (13,139 cases) had a complication rate of 4.25 with mercury bougies, and in 9,431 cases metal olives produced a complication rate of 6.1/1,000 treatments. Dilation for achalasia in 1,224 patients produced a complication rate of 18.4/1,000 procedures. Peritoneoscopy (4,404 examinations) produced a complication rate of 5.4/1,000 patients. The value of these diagnostic and therapeutic procedures is now well established but must be weighed against a potential risk of complications.

Endoscopes↗
PubMed1975

Assay for acetazolamide in plasma.

A method for the analysis of acetazolamide, 5-acetamido-1,3,4-thiadiazole-2-sulfonamide, sensitive to 25 ng/ml in plasma, was developed. After extraction of acetazolamide and its propionyl analog, 5-propionamido-1,3,4-thiadiazole-2-sulfonamide, the internal standard, from plasma with ethyl acetate and removal of lipids from the residue of the ethyl acetate extract with methylene chloride, the sulfonamides were chromatographed on an octadecyl trichlorosilane bonded phase using high-pressure liquid chromatography. The method was developed to study plasma level profiles of different dosage forms of acetazolamide.

Acetazolamide↗
PubMedDate not supplied

Development and operation of a program to obtain volunteer bone marrow donors unrelated to the patient.

Because of recent increases in bone marrow transplantation, the lack of available matched sibling donors has become a problem. This study investigated the feasibility of obtaining volunteer bone marrow donors unrelated to the patient. A program was developed to inform potential donors and obtain their consent for listing in a bone marrow donor registry. Sixty-six percent of whole blood or apheresis donors agreed to participate in the program. There were no demographic differences between those who accepted or declined to participate. Religion, experiences with medical practices, and the attitude of the potential donor's spouse were important factors in the decision to participate. A search for donors was initiated for 127 patients. Thirty searches were not completed, primarily because of patient-related problems. A total of 713 HLA-A and -B antigen-identical donors was located for 63 of the 97 (65%) patients. A total of 40 HLA-A, -B, and -DR antigen-identical donors was located for 18 of these 63 patients. Six of these 18 patients then had one or more donors (total, 9) whose lymphocytes did not react in mixed lymphocyte culture. Thus, using the file of 2147 donors, an HLA-identical donor was located for 6 percent of the 97 patients. None of these patients has yet received a transplant; in four cases this was due to patient-related and in two cases donor-related reasons. The cost to establish the donor program averaged $33.46 (1984) per donor for donors already typed for HLA-A and -B antigens. This experience indicated that, given thorough information about bone marrow donation and transplantation, a majority of blood and apheresis donors will volunteer to donate bone marrow, without feeling pressure to do so. A relatively small donor file provided donors for 6 percent of patients. The long-term value of bone marrow transplantation using unrelated donors and the optimum size of the donor file remain to be established.

Adult↗