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Biomedical subjects

R K Johnson

Publications and source records attributed to R K Johnson.

279 records · Page 16Linked to original sources
PubMedDate not supplied

Effects of prolonged room temperature holding of whole blood intended for preparation of components.

Current FDA regulations require that platelet concentrates must be prepared within four hours of whole blood collection. To determine if this time period was critical for the harvesting of viable platelets and other blood components, whole blood was held at room temperature for four, six or eight hours after which various components were prepared. Our results indicate that up to eight hours storage had no detrimental effect on platelet yield, recovery in vivo or lifespan. AHF activity, supernatant hemoglobin and red blood cell ATP were also unaffected.

Adenosine Triphosphate↗
PubMedDate not supplied

Body fat distribution predicts cardiac risk factors in older female coronary patients.

BACKGROUND: After myocardial infarction, women have higher rates of recurrent coronary events than men. This is caused, at least in part, by a higher prevalence of obesity-related coronary risk factors such as hyperlipidemia, hypertension, sedentary lifestyle, insulin resistance, and diabetes. We studied the relationship between measures of body fat distribution, body composition, aerobic fitness, and dietary intake and several coronary risk factors including lipids, glucose, and insulin levels. METHODS: The study population included 20 women > 60 years of age with recently diagnosed coronary heart disease and a comparison group of 50 healthy women with low-risk coronary risk profiles. Dependent variables included lipid subfractions (fasting, triglycerides, high-density lipoprotein [HDL] cholesterol, and low-density lipoprotein [LDL] cholesterol), glucose levels, and serum insulin levels. RESULTS: Waist-to-hip ratio (WHR) was the best predictor of serum triglyceride levels (r = .65, P = .002), HDL cholesterol level (r = .46, P = .05), and fasting serum insulin levels (r = .76, P < .001) whereas peak oxygen consumption (Peak VO2) was the best predictor of LDL cholesterol (r = .73, P < .001). In a combined population of the 20 coronary patients and 50 healthy age-matched controls, WHR remained the best predictor of serum triglyceride levels (r = .57, P < .001) and insulin levels (r = .63, P < .001) and Peak V02 was the best predictor of HDL (r = .40, P < .001) and LDL cholesterol (r = .57, P = .004). CONCLUSIONS: Body fat distribution and peak aerobic fitness, both modifiable factors, are significant predictors of risk factors for second coronary events in older female coronary patients.

Adipose Tissue↗
PubMedDate not supplied

Effects of levamisole (NSC-177023) and tetramisole (NSC-102063) in experimental tumor systems.

Levamisole and tetramisole had no antitumor effect against the following transplantable syngeneic murine tumors: L1210 leukemia, P388 leukemia, B16 melanoma, Madison 109 lung tumor, and Lewis lung carcinoma. In the Lewis lung carcinoma system there was no effect on primary tumor growth, metastasis, or survival. Tetramisole had a variable effect on the growth of rhabdomyosarcomas and the survival of BALB/c mice following intramuscular inoculation of Moloney sarcoma virus. In two experiments treatment with tetramisole either prior to or following inoculation of Moloney sarcoma virus increased the number of mice with tumor regression as opposed to progressive tumor growth, incrneased the number of long-term survivors, and prolonged the lifespan of mice that died of tumor. In two further tests neither levamisole nor tetramisole had an effect in this system. In mice immunosuppressed with cyclophosphamide prior to virus inoculation, there was not effect of treatment with levamisole or tetramisole.

Animals↗
PubMedDate not supplied

The role of psychological evaluations in occupational hand injuries.

The benefit of including a psychological evaluation of a worker with a hand injury is that additional diagnostic and prognostic information regarding the patient is obtained. Psychological evaluations examine the emotional and social factors that can either complicate recovery from injury or aid in rehabilitation.

Adaptation, Psychological↗
PubMedDate not supplied

Phase I trial of combination therapy with PALA and 5-FU.

PALA is an inhibitor of de novo pyrimidine biosynthesis. Studies combining PALA with 5-FU in experimental models have demonstrated synergistic antitumor activity with only additive toxicity. The phase I study of PALA in combination with 5-FU is described. Sixteen patients received a total of 29 courses of PALA given as a 24-hour infusion daily for 5 days and 5-FU given by iv bolus at the end of each 24-hour PALA infusion. Cycles were repeated at 28-day intervals. Mucositis was dose-limiting when 940 mg/m3/day of PALA was given with 345 mg/m2/day of 5-FU. Diarrhea, skin rash, and myelosuppression (in decreasing order of frequency) occurred but were not dose-limiting. Alopecia occurred in all patients. Objective responses were seen in single patients with large cell carcinoma of the lung, fibrous histiocytoma, and adenocarcinoma of the colon refractory to prior 5-FU therapy. These studies support further phase II evaluation of the PALA and 5-FU combination.

Adenocarcinoma↗
PubMedDate not supplied

Phase I trial of N-(Phosphonacetyl)-L-aspartic acid (PALA).

N-(Phosphonacetyl)-L-aspartic acid (PALA) was given as a 5-day continuous infusion in a phase I trial. Dose-limiting toxic effects noted were diarrhea occurring at doses of greater than or equal to 6 g/m2/course, mucositis occurring at doses of greater than or equal to 7.5 g/m2/course, and skin rash occurring at doses greater than 9 g/m2/course. No significant CNS, hemorrhagic, gastrointestinal, or hematologic toxicity was noted. In patients with measurable tumor volume, no significant antitumor responses were seen. A dose of 9 g/m2/course is recommended for a phase II trial.

Adult↗
PubMedDate not supplied

Characterizing nutrient intakes of children by sociodemographic factors.

Data from 1,392 children ages 1 to 10, who were participants in the U.S. Department of Agriculture 1987-88 Nationwide Food Consumption Survey, were examined to determine how their diets compared with current dietary recommendations and to identify those sociodemographic factors associated with the greatest risk for not meeting the recommendations. Vitamin A, vitamin E, vitamin C, calcium, iron, and zinc were the nutrients most often consumed below recommended levels. Percentage of calories from fat and saturated fat and mean sodium intakes were above recommended levels for the majority of the children. Of the total sample, 81 percent met guidelines for cholesterol intakes. Multiple correlation regression analysis was used to determine the effect of the following factors on the children's nutrient intakes: geographic region, degree of urbanization, race, household size and income, age, education, and employment status of the male and female head of household. Age and sex of the child were entered as control variables. Level of urbanization affected the most nutrient intake variables, followed by race. Living in a rural area and being black were significant predictors for higher intakes of total fat, saturated fat, cholesterol, and sodium. Mean annual household income had no significant effect on any of the diet quality measures. Many of the children in the sample, however, participated in Federal food and nutrition programs that provided additional resources for food.

Black or African American↗