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Biomedical subjects

R Earl

Publications and source records attributed to R Earl.

12 recordsLinked to original sources
PubMed1992

The frequencies of constitutional chromosome abnormalities in an apparently normal adult population.

Constitutional karyotypes were determined in 1405 apparently normal adults referred for population studies of acquired chromosome abnormalities in peripheral blood lymphocytes. A total of 7 translocations (4 reciprocal, 3 Robertsonian), 1 extra structurally abnormal chromosome, 2 47,XXY and 12 inv(9) were detected. An examination of previous population studies illustrates the importance of considering differences in the resolution of the chromosome analysis when comparing frequencies of abnormalities.

Adult↗
PubMed1991

A cytogenetic study of men occupationally exposed to uranium.

Blood lymphocyte cultures from two groups of workers occupationally exposed to uranium were examined for asymmetrical chromosome aberrations and sister chromatid exchanges (SCEs). Significant increases in both cytogenetic endpoints were seen. For dicentrics this appeared to be particularly associated with exposure to soluble uranium. The external radiation exposure experienced by these men was insufficient to explain the increase in dicentrics, and irradiation of lymphocytes by internally deposited uranium would have been minimal. As the SCEs were also raised, the genotoxic effect is likely to be due to the chemical nature of the compound. The increase in frequency of dicentrics associated with smoking was greatest in the group with exposure to soluble uranium suggesting some interaction between the two clastogens. No such interactive effect was seen for SCE frequencies, in which increases attributable to smoking were similar in the worker and control groups.

Adult↗
PubMed1991

Pentobarbital quantification in the presence of phenobarbital by fluorescence polarization immunoassay.

We developed a method for measuring pentobarbital in samples that also contain phenobarbital. The phenobarbital is destroyed by adding sodium hydroxide and then heating at 95 degrees C for 60 min. Pentobarbital is not affected by this pretreatment and can then be measured with an Abbott TDx barbiturates kit. Using this method, we obtained an average analytical recovery of 98% of added pentobarbital and a correlation of y = 0.953x + 3.4 vs HPLC. The intra-assay CV was 3.7% at 25.8 mg/L; the interassay CV was 6.2% at 16.1 mg/L. Other long-acting barbiturates, e.g., hexobarbital, are also effectively destroyed by this alkali pretreatment. Other short-acting barbiturates, e.g., secobarbital, are not removed and would produce an interference.

Chromatography, High Pressure Liquid↗
PubMed1990

Nutrition labeling: issues and directions for the 1990s.

This report will become a part of the comment and rule-making process that FDA and USDA will conduct to achieve food and nutrition labeling reform. The agencies have requested interested parties to comment on the report's recommendations. The report will be of interest to Congress in developing legislative proposals to clarify the legal basis for anticipated reforms. For the food industry, health professionals, and consumer groups, it will be of interest in terms of their own objectives in promoting nutrition labeling changes that are in line with current dietary recommendations and in product development. Dietitians will want to comment on the recommendations in the Institute of Medicine report and on provisions of the proposed regulations. Dietitians should encourage their elected officials in Congress to support legislation for food labeling reform.

Food Labeling↗
PubMed1989

Intravenous meperidine during labor: a randomized comparison between nursing- and patient-controlled administration.

Preliminary reports about patient-controlled analgesia during labor have been promising. The purpose of this investigation was to compare our experience with meperidine given intravenously by the patient versus by a nurse. Sixty-four healthy women beginning active labor (cervical dilation 3 cm) at term were randomly assigned to either self-administer a 10-mg dose as often as every 20 minutes or have a nurse administer 25-50 mg every 3 hours as requested. The total meperidine dose and consumption rates were greater when administered by the patient than by a nurse. Maternal side effects occurred with similar frequency in both groups, and pain relief was judged to be equivalent. Maternal and umbilical serum concentrations of meperidine at delivery increased in the patient-controlled group if active labor lasted longer than 2 hours. Neonatal naloxone therapy was used more often when meperidine was administered by the patient than by a nurse (five of 31, 16%, versus three of 33, 10%, respectively). Self-administration of intravenous meperidine by the laboring patient was not found to be advantageous over nursing administration, and may pose an increased threat to the infant.

Adult↗
PubMed1986

Intracellular protein catabolism: evidence for sequestration of proteins into an intermediate-filament fraction before lysosomal degradation.

Iodinated [125I] glycolytic enzymes (lactate dehydrogenase, pyruvate kinase and glyceraldehyde phosphate dehydrogenase) and bovine serum albumin have been erythrocyte microinjected or scrape loaded into confluent 3T3-L1 cells. The glycolytic enzymes are rapidly (within 30 min) sequestered into a form which is inextractable with sequential treatments with digitonin, Triton X-100 and potassium iodide. Bovine serum albumin is readily extractable by digitonin. Glycolytic enzymes are degraded relatively slowly (t1/2's 124-330 h) by a lysosomal mechanism inhibitable by NH4Cl (50-91%), 3-methyl adenine (62-70%) and leupeptin (47-80%). Bovine serum albumin is degraded relatively rapidly (t1/2 17-20 h) by a non-lysosomal mechanism. Nycodenz density gradient fractionation of homogenates of 3T3-L1 cells after microinjection shows that [125I]-lactate dehydrogenase sediments in a dense fraction containing nuclei (DNA) and lacking cytosolic, lysosomal, plasma membrane or mitochondrial marker enzymes. The [125I]-enzyme is not released from this fraction by the sequential detergent/salt fractionation described above. Analysis of the detergent/salt inextractable residue by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate and 2-mercaptoethanol shows nuclear histones and vimentin. [125I]-lactate dehydrogenase does not enter the polyacrylamide gel in the absence of 2-mercaptoethanol. Importantly endogenous proteins are found in the residue in the presence of leupeptin. The data suggest that sequestration of proteins into a nuclear-intermediate filament fraction may precede lysosomal degradation. Iodinated [125]-Sendai virus HN and F membrane glycoproteins in reconstituted Sendai virus envelope (RSVE) have been fused with growing HTC cells. HN and F are rapidly internalised (within 5 h) to assume a perinuclear distribution before lysosomal degradation. HN and F proteins are either extractable predominantly with triton X-100 or are inextractable by the treatments described above. Nycodenz fractionation of HTC cell homogenates after RSVE-cell fusion shows that HN and F sediment predominantly as a dense peak, enriched in DNA and free from the markers indicated above, and a less dense peak enriched in lysosomal marker enzymes. HN and F proteins translocate from the dense to the less dense peak and are degraded lysosomally (t1/2 av. 70 h). Leupeptin slows the translocation. The detergent/salt inextractable residue is enriched in nuclear histones and vimentin. The data suggest that Sendai viral membrane glycoproteins are sequestered into a nuclear-intermediate filament fraction before lysosomal degradation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1986

Computerized dietary analysis by food groups and by nutrients from food groups.

The professional responsibility of dietetic and nutrition educators and counselors is to provide clients and the public with accurate, understandable information and counseling concerning the relationship of diet to health and disease. Dietary guidance expressed as energy and nutrient content is clear to the nutrition professional, but it frequently is difficult for many clients to comprehend. This study was undertaken to develop a computer software program to analyze dietary data in terms of foods, food groups, and nutrients and to discuss the applications of the computerized assessment. Dietary recalls from a group of noninstitutionalized older women were used for illustrative purposes. Dietary intakes were described in terms of servings consumed of 9 major food groups and 39 major subgroups. Intake of energy and selected nutrients from each major food group was calculated. Recalls were evaluated by comparison with recommended servings from two food guides and recommended energy and nutrient allowances. The information elicited by the software package is useful for monitoring changes in food consumption patterns, assessing dietary compliance, planning, and evaluating nutrition and feeding programs.

Aged↗
PubMed1973

Using the laboratory.

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Clinical Laboratory Techniques↗