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Biomedical subjects

R R Watson

Publications and source records attributed to R R Watson.

At least 181 records · Page 10Linked to original sources
PubMed1987

Effects of dietary retinyl palmitate and selenium on tumoricidal capacity of macrophages in mice undergoing tumor promotion.

Dietary retinyl palmitate was administered for 22-30 weeks in CD-1 mice which had been initiated with 0.15 mumol of 7,12-dimethylbenz[a]anthracene (DMBA) and promoted with 8 nmol of 12-O-tetradecanoylphorbol-13-acetate (TPA) twice weekly thereafter. This treatment resulted in a dose response in both the tumoricidal capacity of a selected number of isolated peritoneal macrophages (PM) and in skin tumor prevention. At 350 I.U./g of diet, retinyl palmitate (RP) also resulted in a 3-fold increase in the number of DM. RP significantly increased the total capacity of macrophage host defenses by increasing the number and individual capacity for cytotoxicity. Selenium (Se), at 2 parts/million in the drinking water, did not enhance PM tumoricidal capacity, although it did result in 60% reduction of mouse tumor burden.

Animals↗
PubMed1987

The effects of caffeine on various body systems: a review.

Caffeine is the most widely consumed drug in Western society. The intake of caffeine-containing beverages in many adults and children often reaches levels that can induce pharmacological effects. Ninety-nine percent of ingested caffeine is absorbed and distributed to all tissues and organs. The effects of caffeine intake differ greatly according to acute or chronic intake, level of intake, and the development of tolerance. Caffeine administered acutely to non-users or recent abstainers can induce hypertension, arrhythmias, altered myocardial function, increased plasma catecholamine levels, plasma renin activity, serum cholesterol levels, increased production of urine, gastric acid secretion, and alterations in mood and sleep patterns. Tolerance to chronic caffeine intake develops in most individuals, with the cessation of its effects on the renal system, the cardiovascular system, the gastrointestinal system and, to some extent, the central nervous system. Moderate caffeine consumers probably need to have little concern for the effect of caffeine intake on their health if their other life-style habits are also moderate.

Adult↗
PubMed1986

Inhibition of ethanol induced ethane exhalation by carcinogenic pretreatment of rats 12 months earlier.

The exhalation of ethane was used as a measure of in vivo lipid peroxidation in rats treated with the hepatocarcinogen diethylnitrosamine followed by 2-acetylaminofluorene (AAF), and carbon tetrachloride, and subsequently fed a liquid diet containing 7% ethanol for 12 months. The other groups consisted of animals treated with methylbenzylnitrosamine (MBN), an esophageal carcinogen, or non-carcinogen pretreated animals with or without 7% ethanol feeding. Ethane production was increased in rats consuming ethanol irrespective of their pretreatment with MBN. In sharp contrast, the ethanol-induced increase of ethane production was absent in rats given the hepatocarcinogenic regime. Our results strengthen recent observations indicating decreased susceptibility of tumor cells to lipid peroxidation. In addition, they confirm the debated concept that there is increased lipid peroxidation following ethanol consumption.

2-Acetylaminofluorene↗
PubMed1986

Effects of selenium in vitro on human T-lymphocyte functions and K-562 tumor cell growth.

In vitro E-rosette formation, lymphocyte mitogenesis, and natural killer (NK) cell activity of human blood lymphocytes were strongly inhibited by high concentrations (10(-4) M) of sodium selenite, sodium selenate, and selenium dioxide. Lower concentrations (10(-5) or 10(-7) M) also inhibited E-rosette formation and natural killer cell activity against K-562 tumor cells. Lymphocyte transformation induced by concanavalin A (con A) or pokeweed mitogen (PWM) was also inhibited by all selenium compounds tested, but only at the highest concentrations (10(-5) and 10(-4) M). There was depression of the total number of viable lymphocytes following incubation with selenium dioxide only at a high concentration (10(-4) M). Interferon production was enhanced at lower levels (10(-9) to 10(-6)M) of selenium dioxide while a higher concentration (10(-5) and 10(-4)M) appeared to inhibit its production. The mechanism of inhibition by selenium compounds (10(-4) M) is due, in part, to the decrease of viable lymphocytes. It is unclear how other and lower concentrations (10(-7) or 10(-9) M) of selenium compounds inhibit E-rosette formation, NK activity, or K-562 tumor cell growth.

Adult↗
PubMed1986

Cellular immune functions of adults treated with a daily, long-term, low dose of 13-cis retinoic acid.

The effects of long-term consumption of 13-cis retinoic acid (13-cRA) on cellular immune functions were measured in young, adult volunteers. The retinoid was administered for 9 months at about 0.13 mg/kg/day. The mean 8AM concentrations of 13-cRA ranged between 30 and 60 ng/ml of serum throughout the study. Corticosteroid levels in plasma decreased significantly throughout treatment, declining from 15.2 ug/dL to 9.1 mg/dL (p less than 0.05). T-cell mitogenesis stimulated by PHA or A Con A was not significantly affected, although this parameter was slightly depressed during the first 2 months of treatment. The percentage of B-lymphocytes tended to decrease during treatment and returned to normal after cessation of 13-cRA (p less than 0.05), while the percentage of T-cells as measured by E-rosette and by fluorescent antibody tagging of surface antigens did not change. The percentage of non T-cells tended to increase slightly during treatment.

Adrenal Cortex Hormones↗
PubMed1986

Thymosin fraction 5: effects on T cell functions in mice immunosuppressed by severe dietary protein deficiency.

The present studies were performed to determine the effects of severe protein deficiency and subsequent injection of thymosin fraction 5 (TF5) on T and B cell functions. BALB/c mice, 4 weeks old, were fed a normal protein (21%), a low protein (4%) or a protein free (0%) diet and then injected with TF5 or buffer (PBS). A significant increase was observed in the PHA (phytohemagglutinin) and LPS (lipopolysaccharide) induced mitogenesis with increasing age of the well-nourished, PBS injected animals. The severely protein malnourished mice, PBS injected and the well nourished mice, injected with TF5 had smaller increases in both B and T cell mitogenesis with increasing age. TF5 injection of the malnourished mice increased PHA and LPS mitogenesis nearly to the levels of the well-nourished mice. The protein malnourished mice consistently had higher serum corticosteroid levels than controls. No changes in serum corticosteroids were observed with TF5 injection of controls, but there was a significant decrease in the corticosteroid levels of the severely malnourished with TF5 injection. Cytoxicity assays of T cell function, antibody dependent cellular cytoxicity and cytoxicity to mouse thymona tumor cells, in mice fed moderately protein deficient diets showed suppression compared to controls fed 20% protein. TF5 injection partially and temporarily increased these functions in the malnourished mice.

Animals↗
PubMed1986

Identification of alcohol abuse and alcoholism with biological parameters.

The prevalence and incidence of heavy alcohol consumption are major problems which have been increasing in many countries in recent years. It is crucial for physicians to consistently identify early drinking problems as well as the various end disease states in order to minimize suffering and maximize recovery. This paper reviews the evolutionary development of clinical tools for detection of alcohol abuse. The focus is primarily on clinical/biochemical indicators of alcohol abuse, emphasizing but not limited to changes in hematological characteristics, liver enzyme activity, lipids, immune function factors, hormones, neurological factors, and some physically based tests. Use of test combinations and sophisticated statistical analysis of pattern changes in test batteries evidence increased diagnostic efficiency.

Alcoholism↗
PubMed1986

Plasma fatty acid pattern including diene-conjugated linoleic acid in ethanol users and patients with ethanol-related liver disease.

The level of conjugated dienes (CD) in the serum, conjugated linoleic acid isomer in the phospholipid fraction [18:2(9, 11)], and the fatty acid profile in both the serum and in the separated lipid classes were analyzed in current and previous alcohol abusers and in patients with alcoholic liver disease. None of the subjects consumed alcohol for at least 2-3 days prior to blood collection for analysis of lipids. There was no significant difference in CD or in the absolute level of 18:2(9, 11) among the groups, whereas the 18:2(9, 11)/18:2(9, 12) molar ratio was significantly elevated in patients with liver disease. Fatty acid analysis of the whole plasma extract showed that the absolute level of arachidonic acid increased from 4.8 +/- 3.5 mg/dl (n = 9) in lifelong abstainers to 13.4 +/- 4.0 (n = 8) in current ethanol abusers, and its relative level (related to the total fatty acids) from 1.73 +/- 1.34 to 4.55 +/- 1.01 in the same groups. An increased proportion of linoleic acid in the triglyceride and phospholipid fractions from current abusers and patients with liver disease was also found; the percentage of 18:2 in phospholipids increased from 5.4 +/- 5.0 (n = 8) in lifelong abstainers to 14.3 +/- 3.9 (n = 8) in current abusers and 12.7 +/- 2.2 (n = 10) in patients with liver disease. The percentage of 16:0 was significantly lower in the phospholipids of current abusers as compared to lifelong abstainers.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Nutrient intakes: cancer causation and prevention.

High intakes of the macronutrients--proteins, lipids, and carbohydrates in the form of excess energy-have some cancer stimulating properties. On the contrary, epidemiologic and animal laboratory data indicate that high-level supplementation of some micronutrients--certain vitamins, minerals, and lipotropes, as well as some non-nutrients, most notably various types of dietary fiber, may be useful in the prevention of cancer. A wealth of data exists for macronutrients whereas most micronutrients are almost unstudied concerning their role in cancer prevention. Vitamins A, E, and C and selenium are the most well-studied micronutrients, and are recognized as effective with significant anticancer effects, at least in animal models. There are minimal data to suggest that some other micronutrients may also exert varying degrees of incidence reduction on one or more types of cancer. This is most true for folic acid, manganese, molybdenum, copper, the amino acids phenylalanine and methionine, and the lipotrope choline. Zinc and vitamins B1, B2, B6, B12 and pantothenic acid have even less data, and some data are contradictory. Therefore, it is premature to make recommendations concerning their usefulness in cancer prevention at present.

Animals↗
PubMed1986

Modification of cellular immune functions in humans by endurance exercise training during beta-adrenergic blockade with atenolol or propranolol.

Young, healthy, previously inactive men were trained aerobically 40 to 50 min X d-1, 5 d X wk-1 for 15 wk. They were randomly assigned to one of three medication groups: placebo, propranolol (160 mg X d-1), or atenolol (100 mg X d-1). All subjects lost weight and decreased relative body fat as a result of training. Following training, submaximal steady-state heart rates were reduced in all groups. Maximal oxygen uptake and maximal treadmill times were also increased in all groups. The VO2max of the placebo increased 18.4%. While that of the atenolol group increased 19.4%, the propranolol group went up 17.0%. After training the maximal heart rate did not change in the placebo group, while treatment with propranolol and atenolol reduced at 24.6 and 21.9%, respectively. Training caused a significant decrease in the natural killer cell activity in all three groups. The placebo group had 38.8% +/- 3.8 (SD) before and 29.3 +/- 3.2% lysis of target cells by natural killer cells after physical conditioning, which was significantly lower (P less than 0.01). The groups treated with propranolol and atenolol were also similarly decreased. The use of propranolol or atenolol had no additional significant effect on natural killer cell activity. T-cell mitogenesis stimulated with a mitogen significantly increased with conditioning. The groups given atenolol or propranolol tended to increase somewhat more than the placebo group, although this difference was not statistically significant. There was no significant change in the percentage of total lymphocytes isolated due to training or beta-blockade.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Selenium and vitamins A, E, and C: nutrients with cancer prevention properties.

It has been estimated that 35% of all cancer incidence is related to diet. The potential appears great that high intakes of various nutrients can reduce the incidence of some types of cancer. Selenium and vitamins A, C, and E, discussed in this article, have many actions and interactions that are important in relationship to the study of nutrition and cancer. Even though only a few of the necessary human trials of efficacy have been conducted, epidemiological and animal data suggest that vitamins and/or minerals act as anticarcinogens, altering cancer incidence, differentiation, and growth. Thus, they may prove useful adjuncts to conventional therapies or in cancer prevention. However, the nutrients should not be viewed as cure-alls that work alone. Adequate intake ideally should be the result of increased dietary consumption rather than supplements because as yet unidentified components found in food may prove beneficial and protective. More research is needed prior to encouraging members of the general population to increase their intakes of various nutrients, even though there is now some evidence that those nutrients may help prevent some cancers.

Animals↗
PubMed1986

Immunological enhancement by fat-soluble vitamins, minerals, and trace metals: a factor in cancer prevention.

High intakes of some fat-soluble vitamin or trace metals have been associated with a decreased risk of cancer. A mechanism to help explain their anticancer action might be immunosuppression during deficiency or immuno-enhancement with high intakes. In vitro, retinol suppressed T-lymphocyte functions, whereas high dietary vitamin A enhanced macrophage functions. High intakes of vitamin E can enhance some anticancer, immune defenses. Selenium excess was not very suppressive of immune functions in vitro, but did retard tumor cell growth. Selenium and zinc deficiencies are associated with immunosuppression. Enhanced immune functions by high intakes of trace elements and vitamins provide a mechanism to explain in part the concomitant decreased cancer incidence.

Diet↗
PubMed1985

Effect of age, malnutrition and renutrition on free secretory component and IgA in secretions.

The development of free secretory component (FSC) was studied in the tears of normal infants, children and adults. The level of FSC in tears was higher in older adults than in children. Free secretory component was also measured in the tears of normal, moderately and severely malnourished Colombian children. Children suffering from kwashiorkor, combined protein-calorie malnutrition or marasmus were studied before and after renutrition. No change was detected in the concentration of FSC in tears of moderately malnourished (Grade I and II) children. There was a significant difference between normal and severely malnourished children which improved with renutrition. The levels of tear IgA were decreased in the moderately malnourished children. These results indicate that reduction in secretory IgA levels in moderate malnutrition may not be explained by a lack of available free secretory component in tears, but that severe malnutrition may impair the S-IgA system by significantly reducing the availability of free secretory component.

Adolescent↗
PubMed1985

Effects of retinoids on human lymphocyte functions in vitro.

E-Rosette formation in vitro, lymphocyte mitogenesis and natural killer (NK) activity of human blood lymphocytes were strongly inhibited by high concentration (10(-4) M) of retinol or retinal. Other retinoids at 10(-4) M (retinoic acid and 13-cis-retinoic acid) and lower concentrations (10(-7) or 10(-9) M) of retinol, retinal and carotenes also inhibited E-rosette formation. Lymphocyte transformation responses induced by concanavalin A (Con A) or pokeweed mitogen (PWM) were also inhibited while NK activity was not affected. There was a remarkable depression of the total number of viable lymphocytes after incubation with retinol or retinal 10(-4) M. However, other retinoids, 10(-7) and 10(-9) M of retinol and retinal and carotenes did not show marked decrease of lymphocyte number or viability even after prolonged incubation (48 h). The mechanism of inhibition by retinol or retinal (10(-4) M) is due in part to the decrease of viable lymphocytes. It is unclear how other retinoids, carotenes and lower concentrations (10(-7) or 10(-9) M) of retinol or retinal inhibit E-rosette formation or lymphocyte transformation.

Adult↗
PubMed1985

High dietary vitamin A (retinyl palmitate) and cellular immune functions in mice.

High dietary intakes (4000-650,000 IU/kg diet) of vitamin A (retinyl palmitate, RP) modified the functions of peritoneal macrophages (PM). The number of peritoneal exudated cells (PEC) obtained from CD-1 mice increased significantly at both 7 and 10 weeks after initiation of the RP diets. The percentage of PM in PEC showed no significant difference between dietary groups and was at levels of 55-60%. PM from mice fed high RP diets showed higher tumoricidal activities than PM from controls without any preincubation with macrophage activators. Enhancement of in vitro tumoricidal activity of PM increased with increasing contents of RP in the diets, reaching 30% lysis by PM isolated from mice fed the highest RP (650,000 IU/kg diet) diet. However, the in vitro activation of tumoricidal ability of PM by macrophage-activating factor (MAF) was inversely correlated with the dietary RP content. The tumoricidal activities of PM from mice fed the highest RP diet were not enhanced by MAF. However, these PM showed an increased ability to phagocytose SRBC and opsonized SRBC compared to controls. Splenocytes and thymocytes were incubated with [3H]thymidine immediately after isolation and their mitogenic activities were measured. Splenocytes, but not thymocytes, isolated from mice fed the highest RP diet had increased mitogenesis. On the other hand, NK activity was not affected by dietary RP intake. There was a similar lysis of target cells by both splenocytes and thymocytes from mice fed diets with various RP levels. IL-1 was produced from PM by incubation with LPS, and its production was assessed using the proliferation of normal mice thymocytes. Production of IL-1 in vitro showed about a two-fold increase using cells from mice fed the highest RP diet compared to controls. High RP diets induced increased phagocytic ability and tumoricidal activity of PM but did not enhance NK activity. These findings suggest that high RP diet may cause activation of PM.

Animals↗
PubMed1984

Resistance to bacterial and parasitic infections in the nutritionally compromised host.

Over the past few years the relationships and interactions of diet, disease, and immunology are becoming better defined with the development and understanding of host defenses. Nutritional state, immunity, and disease all influence each other in the hospitalized patient, the elderly, and the young. Disease can alter nutritional needs and immune responses to antigens. The roles of both dietary excesses and deficiencies on cellular, secretory, and humoral immune responses are related to diseases and disease incidence in humans and experimental animals. Malnutrition alters incidence and severity of fungal, bacterial, viral, and parasitic pathogens. The mechanisms of altered disease resistance in nutritionally stressed animal models occurs via changes in the lymphoreticular endothelial system. The effects of common nutritional deficiencies, low protein, and low carbohydrate diets on antibody production, macrophage function, secretory IgA synthesis, and T-cell functions. Nutritional supplementation can increase lymphocyte function and decrease growth of some pathogens and tumors. Alternatively, obesity and high fat have roles in infectious disease and immunity.

Amino Acids, Essential↗