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Biomedical subjects

K Anderson

Publications and source records attributed to K Anderson.

At least 451 records · Page 25Linked to original sources

Hospital haunts.

Explore the source record for details and available documents.

Hospitals↗

Comparison of selective media for the isolation of salmonellae.

A study of the selective action of four fluid media used for the isolation of salmonellae is described. When incubated in the presence of three competing organisms, test strains were recovered most frequently from Rappaport medium but mannitol selenite broth proved superior for the isolation of S. typhi.

Culture Media↗

Comparison of baseline and repeated measure covariate techniques in the Framingham Heart Study.

The purpose of this paper is to indicate how repeated measures on risk factors have been employed in the prediction of the development of disease in the Framingham Heart Study. Since these measures vary over time, the method accounts for time dependent covariates. The technique is a generalized person-years approach in that it treats each observation interval (of equal length) as a mini-follow-up study in which the current risk factor measurements are employed to predict an event in the interval. Observations over multiple intervals are pooled into a single sample to predict the short term risk of an event. This approach is compared to the long-term prediction of disease which utilizes only the baseline measurements and ignores subsequent repeated measures on the risk factors.

Blood Pressure↗

Induction of nucleolar changes in rat luminal cells by single injection or low-dose infusion of estradiol.

The nucleolar area of rat uterine luminal epithelial cells was measured for 41 h after beginning either of two dosage regimens of estradiol (E2): a single injection of 1.0 microgram E2 or a continuous infusion of E2 at a rate of 1.0 microgram/24 h. In response to a single injection of E2, mean nucleolar area was significantly elevated above control levels by 10 h. Nucleolar morphology showed slight changes, but the fibrillar component was always associated with 2-3 fibrillar centers by 10 h. In response to a continuous infusion of E2, mean nucleolar area was elevated by 10 h, reached a maximum by 18 h, and remained relatively constant thereafter. Nucleolar morphology showed significant changes by 10 h; the fibrillar component was commercially denser. Bivariate histograms of nuclear versus nucleolar areas showed a bimodal distribution after both injection and infusion, suggesting that two size classes of nuclei existed after estrogen stimulation. The results suggest that: 1) a continuous infusion of E2 at a rate of 1.0 microgram/24 h was more effective in inducing larger increases in nucleolar area and transcription than a single injection of 1.0 microgram E2 at time 0; 2) using analysis of nuclear and nucleolar areas two subpopulations of cells were identified; and 3) continuous infusion of E2 produced a steady state of ribosome production and cytoplasmic transport by 18 h.

Animals↗

Tissue distribution and innervation pattern of peptide immunoreactivities in the rat pancreas.

The distribution of calcitonin gene-related peptide (CGRP), substance P/tachykinin (SP/TK), vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY) and gastrin-releasing peptide (GRP) immunreactivities (IR) in the rat pancreas was investigated using radioimmunoassay and immunohistochemistry. CGRP, NPY and VIP tissue contents are much higher than GRP and SP/TK concentrations. Peptide-containing nerves are distributed to both the exocrine and endocrine pancreas. However, differences exist in terms of density and targets of innervation for each peptidergic system. In the acini and through the stroma, fibers IR for CGRP, NPY and VIP are greater than GRP- and SP/TK-containing processes. The vasculature is supplied by a prominent NPY, CGRP and, to a lesser extent, SP/TK innervation. VIP-IR is found occasionally, and GRP-IR is never detected, in fibers associated with blood vessels. Around ducts, CGRP- and NPY-positive neurites are greater than SP/TK- greater than or equal to VIP-IR fibers, whereas GRP-containing nerves are not visualized. In the islets, the density of peptidergic nerves is: VIP-, GRP- greater than or equal to CGRP-IR greater than NPY or SP/TK. In intrapancreatic ganglia. VIP- and, to a lesser extent, NPY-IRs are found in numerous neuronal cell bodies and in nerve fibers; GRP-IR is present in numerous nerve processes and in few cell bodies; CGRP- and SP/TK-IRs are detected only in fibers wrapping around unlabeled ganglion cells. The majority of CGRP-IR fibers contain SP/TK-IR. The existence of differential patterns of peptidergic nerves suggests that peptides exert their effects on pancreatic functions via different pathways.

Animals↗

Sex differences in schedule-induced alcohol consumption.

Six female and five male Wistar rats obtained food by pressing a lever on a fixed-interval (FI) 60-s schedule in the presence of a sipper tube which allowed access to an alcohol solution. Systematic manipulation of the alcohol concentration revealed that male rats consumed higher alcohol concentrations (v/v) than female rats to obtain maximum alcohol intake (g ETOH/kg) during an experimental session. Males also reached higher blood alcohol levels (BALs) than females. Individual lick rates varied over a small range when the FI schedule parameter was manipulated (20 s and 180 s) during probe sessions. Very few licks were observed when all pellets were presented at the beginning of the session, during extinction, or during sessions in which only a few pellets were presented. Reduction of the solution's alcohol concentration to half the maximum concentration or presentation of distilled water resulted in increased lick rates at most values of the FI schedule in four of the five male subjects, but not in female subjects. Alcohol intake during sessions in which half the maximum alcohol concentration was available was lower than that observed during sessions in which subjects consumed the maximum alcohol concentration. The lick rate data in conjunction with those on alcohol intake suggest that male rats, but not female rats, maintained blood alcohol concentrations at levels which they had also reached during sessions in which the maximum alcohol concentration was available from the sipper tube.

Alcohol Drinking↗

Lipids and risk of coronary heart disease. The Framingham Study.

Total cholesterol level is significantly related to risk of coronary heart disease (CHD), adjusting for other risk factors in women 50 to 79 years old and in men aged 50 to 64 years, at P < .001. Determining the levels of lipoproteins such as low-density-lipoprotein (LDL) cholesterol and high-density-lipoprotein (HDL) cholesterol improves the prediction of risk. Triglycerides are independently related in women at all ages but miss statistical significance in the multivariate studies in men. The total cholesterol-HDL cholesterol ratio is another powerful predictor at all ages in women and is the only lipid predictor independently related to CHD in men 65 to 80 years old. Inspection of the age-specific association of cholesterol with risk in men and women also reveals that the absolute rates of disease worsen with age.

Age Factors↗