Biomedical subjects

D Denton

Publications and source records attributed to D Denton.

At least 19 recordsLinked to original sources

PubMed1995

The effect of increased salt intake on blood pressure of chimpanzees.

A colony of 26 chimpanzees given a fruit and vegetable diet of very low Na and high K intake were maintained in long-standing, socially stable small groups for three years. Half of them had salt added progressively to their diet during 20 months. This addition of salt within the human dietetic range caused a highly significant rise in systolic, mean and diastolic blood pressure. The change reversed completely by six months after cessation of salt. The effect of salt differed between chimpanzees, some having a large blood pressure rise and others small or no rise. These results in the species phylogenetically closest to humans bear directly on causation of human hypertension, particularly in relation to migration of preliterate people, with low Na diet, to a Western urban lifestyle with increased salt intake. The hedonic liking for salt and avid ingestion was apt during human prehistory involving hunter-gatherer-scavenger existence in the interior of continents with a scarcity of salt, but is maladaptive in urban technological life with salt cheap and freely available.

Animals↗

PubMed1995

Exposure to blood and body fluid: factors associated with non-compliance in follow up HIV testing among health care workers.

Due to lack of previous research, this study examined the factors associated with non-compliance in follow up human immunodeficiency virus (HIV) testing among health care workers after blood and/or body fluid exposure. A descriptive correlation design was used with 178 health care workers who did not return for recommended follow up HIV testing post-blood and/or body fluid exposure at three urban hospitals. The 36 question Likert scale was designed to measure the five concepts of the Health Belief Model: susceptibility, seriousness, benefit, barriers, and health motivation. The internal consistency reliability measured .48. Forty five subjects (25%) returned the questionnaire. The most significant factor determined to affect return rate for follow up testing was related to benefits and susceptibility (F = 4.57, df = 2.42, R = .42, P = .02). Return rate was most significantly correlated with the idea of decreasing the chance of dying from acquired immunodeficiency syndrome (AIDS) (r = .31, P = .04). Similar results of recommended future studies may indicate changes in post-exposure education or institutional policies and procedures.

Adult↗

PubMed1995

Surveillance cultures in bone marrow transplant recipients: worthwhile or wasteful?

A prospective study of the value of surveillance cultures was performed in a bone marrow transplant (BMT) unit among 48 consecutive patients. All patients were admitted to laminar airflow or high-efficiency particulate air (HEPA) filtered rooms, maintained on reduced microbial diets and received oral non-absorbable antibiotics. With the onset of neutropenia, all patients received imipenem/cilastatin and 17 patients received low-dose amphotericen B 0.1 mg/kg/day. Pre-transplant and weekly post-transplant cultures of the stool, throat and urine were obtained on all patients. Nasal and vaginal cultures were performed on 26 patients. Sixteen patients developed 23 documented infections. The sensitivity of surveillance cultures for all infections was 38%, specificity 25%, positive predictive value 20% and negative predictive value 44%. When stratified by organisms, the sensitivity, specificity, positive predictive value and negative value were: Gram positive infections, 33%, 36%, 11%, 70%, Gram negative infections, 17%, 88%, 17%, 88%; fungal infections 37%, 50%, 11%, 75%; and Candida albicans, 100%, 57%, 14%, 100%. These data suggest that surveillance cultures may be useful to exclude C. albicans infections but are of limited value in predicting other types of infections in recipients of BMT.

Adolescent↗

PubMed1990

Immunohistochemical detection of c-myc oncoprotein in paraffin embedded tissues.

In almost all studies using paraffin embedded tissue, c-myc protein has been found in the cytoplasm of cells. Since the protein is normally localized in the nucleus it is difficult to determine which histochemical observations are real and which are artefactual. The study designed here evaluated several different methods of fixation prior to paraffin embedding in an attempt to identify which would prevent the diffuse of the protein out of the nucleus. Using various fixation procedures (formalin, paraformaldehyde, B-5, Zamboni and AMeX) we found that fixation in cold acetone (-20 degrees C) overnight followed by 2x15 min fixation in acetone at +4 degrees c and at room temperature, cleared in methyl benzoate and xylene (AMeX procedure) gives reproducible nuclear staining when a variety of normal and tumor tissues are treated with an anti c-myc protein antibody. This method was then compared to frozen sections. While there was no cytoplasmic staining in same tissue specimens in both AMeX processed and frozen sections, the tissue architecture was much better preserved in AMeX processed samples. Our data strongly suggest that AMeX fixation, originally developed for T and B lymphocyte antigens, should be used for immunolocalization of c-myc oncoprotein in paraffin embedded tissues.

Cell Nucleus↗

PubMed1988

Influence of pregnancy and lactation on Na appetite of BALB/c mice.

The effect of pregnancy and lactation on sodium appetite, water, and food intake of young adult BALB/c mice was studied. Voluntary sodium intake increased fourfold during the last 3 days of gestation. Water and food intake and body weight also increased significantly. During the last 14 days of lactation, sodium intake was increased significantly three- to fivefold, relative to base-line period and a control group. Large significant increase of water and food intake occurred also during lactation. After weaning, intake returned to base line. Calculation of sodium sequestered in young in utero and provided to pups during lactation showed increased voluntary intake in great excess of metabolic need, suggestive of hormonal determination of sodium appetite during reproduction as in wild rabbits.

Animals↗

PubMed1988

Na deficiency and other physiological influences on voluntary Na intake of BALB/c mice.

BALB/c mice exhibited a small hedonic intake of 0.3 M NaCl, which was not influenced by change from high to low salt diet or by withholding access to NaCl solution for 1 day. Sodium deficiency produced by furosemide injection consistently caused a highly significant increase in sodium intake. Sodium deficiency was corrected rapidly over 10 min. The appetite was specific for sodium in a cafeteria experiment and was exhibited by naive animals on the first experience of sodium deficiency and subsequent access to salt. The appetite was significantly related to the extent of body deficit, but overdrinking proportionate to initial deficit was characteristic. No increase in sodium intake occurred with repeated experience of sodium deficit. Water deprivation caused a subsequent increase of sodium intake. Total deprivation of food for 48 h caused a large sustained increase of sodium intake, but reduction of food intake by 40% did not influence sodium appetite.

Animals↗

PubMed1987