Nutritional Alterations Research Articles

Aging: a barrier to renutrition? Nutritional and immunologic evidence in rats

Previous reports suggest that correcting the malnourished state is more difficult in elderly people than in younger ones and that protein requirements may be higher in elderly than in younger adults. The aim of this study was to establish whether malnourished old rats respond to protein-supplemented nutritional repletion as do young adult rats. Adult (3 mo old) and old (22 mo old) rats were submitted to dietary restriction programs that induced similar metabolic and nutritional alterations. Malnourished adult and old rats were then killed (R groups) or refed for 1 wk with a high-protein diet (HPD; 23% protein) or a very-high-protein diet (VHPD; 27% protein). Control groups at both ages were fed ad libitum throughout the experiment. Effects of food repletion were evaluated in terms of protein metabolism, intestinal histomorphometry, and nonspecific immune status. In adult rats, HPD sufficed to increase body weight and restore basal values of liver weight and protein content (P: < 0.01 compared with the R adult group), nitrogen balance (P: < 0.01 compared with the R adult group), and hydrogen peroxide production by polymorphonuclear neutrophils and monocytes (P: < 0.01 compared with the R group); VHPD had no supplementary effect except on nitrogen balance. In old rats, HPD was less effective and greater benefit was observed with VHPD in terms of body weight gain (10%; P: < 0.01 compared with the old group fed HPD), albuminemia, muscle weight and protein content, plasma arginine concentration, and hydrogen peroxide production by stimulated polymorphonuclear neutrophils and monocytes compared with the old R group (P: < 0.01). Aging is a significant variable affecting the response to nutritional support.

Complementary and alternative therapies to manage HIV-related symptoms.

Persons with HIV infection report substantial use of complementary and alternative medical (CAM) therapies for symptom management. Anecdotal reports from patients indicate that CAM approaches are helpful; however, there is limited scientific information on the safety and efficacy of these therapies in the HIV population. The purpose of this review is to critically appraise the scientific evidence for selected CAM therapies that are used by HIV-infected persons to manage three common symptoms: nutritional alterations, pain, and depression.

Peroxisome proliferator-activated receptor gamma target gene encoding a novel angiopoietin-related protein associated with adipose differentiation.

The nuclear receptor peroxisome proliferator-activated receptor gamma regulates adipose differentiation and systemic insulin signaling via ligand-dependent transcriptional activation of target genes. However, the identities of the biologically relevant target genes are largely unknown. Here we describe the isolation and characterization of a novel target gene induced by PPARgamma ligands, termed PGAR (for PPARgamma angiopoietin related), which encodes a novel member of the angiopoietin family of secreted proteins. The transcriptional induction of PGAR follows a rapid time course typical of immediate-early genes and occurs in the absence of protein synthesis. The expression of PGAR is predominantly localized to adipose tissues and placenta and is consistently elevated in genetic models of obesity. Hormone-dependent adipocyte differentiation coincides with a dramatic early induction of the PGAR transcript. Alterations in nutrition and leptin administration are found to modulate the PGAR expression in vivo. Taken together, these data suggest a possible role for PGAR in the regulation of systemic lipid metabolism or glucose homeostasis.

Is infection risk linked to exercise workload?

Anecdotal, survey, and epidemiological data suggest that endurance athletes are at an increased risk for upper respiratory tract infection (URTI) during periods of heavy training and the 1 - to 2-wk period after race events. The majority of athletes, however, who participate in endurance race events do not experience illness. Of greater public health importance is the consistent finding of a reduction in URTI risk reported by fitness enthusiasts and athletes who engage in regular exercise training while avoiding overreaching/overtraining. Although it naturally follows that infection risk should in some way be linked to acute and chronic exercise-induced alterations in immunity, attempts thus far to measure this association have been unsuccessful. There is growing evidence that for several hours subsequent to heavy exertion, several components of both the innate and adaptive immune system exhibit suppressed function. The immune response to heavy exertion is transient, however, and further research on the mechanisms underlying the immune response to prolonged and intensive endurance exercise is necessary before meaningful clinical applications can be drawn. Some attempts have been made through chemical or nutritional means (e.g., indomethacin, glutamine, vitamin C, and carbohydrate supplementation) to attenuate immune changes after intensive exercise to lower the risk of infection. No consistent relationship between nutritional interventions, exercise immunology, and alteration in URTI risk has yet been established.

Maternal and Early Dietary Fatty Acid Intake: Changes in Lipid Metabolism and Liver Enzymes in Adult Rats

Over the last decade, much evidence has emerged to suggest that alterations in maternal nutrition during pregnancy may irreversibly affect aspects of physiological and biochemical functions in the fetus. This study was designed to determine the mechanisms involved in these alterations. Our hypothesis was that the type of maternal dietary fat received in early life could determine the level of lipoprotein lipase (LPL; EC 3.1.1.34) activity and gene expression which would be maintained into later life. A diet high in (n-3) polyunsaturated fatty acids was predicted to be associated with higher levels of lipoprotein lipase (LPL) activity and expression and lower levels of plasma triglyceride after a high fat meal challenge. Using a 2x2 factorial design, Wistar Albino rats were pair-fed either a fish oil diet (50 g/kg) or a mixed oil diet (50 g/kg) for the last 2 wk of gestation, during lactation and pups were fed these diets until 5 wk of age. After 5 wk, the rats were fed nonpurified diet. The rats were killed at 5 wk (young) or 10 wk (adult) of age after a mixed oil (50 g/kg) test meal. There were significant age effects on plasma triglyceride (P<0.02), cholesterol (P<0.001), glucose-dependent insulinotrophic polypeptide (GIP) (P<0.001) and liver glutathione reductase activity (P<0.05) which were all higher in the young rats compared to the adults. There were significant effects of diet on triglyceride (P<0.001), cholesterol (P<0.001) and LPL mRNA levels (P<0.001). GIP and triglyceride levels were significantly correlated (r = 0.66; P<0.001). Omental adipose tissue LPL activity as significantly higher in the fish-oil fed groups compared to the other groups (P<0.001), whereas Epididymal adipose tissue LPL mRNA was significantly higher in the mixed oil-fed adults compared to the other groups (P<0.001). The latter result suggested an imprinting effect of fatty acid composition in early life on LPL gene expression. Liver superoxide dismutase activity was affected by age and diet and was higher in the young than in the adults and higher in the fish oil-fed young than in those fed the mixed oil-fed (P<0.005). Catalase activity was also affected by age (P<0.001) and diet (P<0.001), and there was a significant interaction between age and diet (P<0.001). Catalase activity was higher in rats fed fish oils at both stages of development, suggesting that feeding fish oils to rats in early life raises oxidative stress throughout life. The majority of the significant differences shown were between the age groups and not between the two dietary groups, suggesting that postprandial handling of a standard fat meal is affected more by age than by early dietary fatty acid composition. However, the mechanisms of biological imprinting of fatty acids on LPL expression and on enzymes related to oxidative stress requires more investigation.

Is Altered Nutritional Status the Root Cause of Your Clients' Negative Outcomes?

The impact of altered nutritional status is costly. Surgical patients have 2-3 times the risk of complications, length of stay is extended by 90%, and charges are 35-75% higher. Risk factors are numerous; therefore, collaboration among all members of the health care team is required to impact patient outcomes positively. The purpose of this article is to review the significance of alteration in nutrition and its impact on patient outcomes. The article demonstrates two approaches to improve the quality of care given to clients with an identified alteration in nutritional status: a clinical research project and a quality improvement project.

Patología de los síndromes paraneoplásicos del sistema nervioso central, periférico y músculo

The paraneoplastic neurological syndromes are alterations associated with neoplasias. However, they are not caused by metastases or complications such as infections, vascular disorders, metabolic or nutritional alterations or secondary effect of treatment. The paraneoplastic syndromes are often associated with the creation of autoantibodies against antigens produced by the neoplastia, but also may be against other cells or target molecules of the patient. Sometimes, especially with antibodies directed against cell membrane proteins, there is a close relationship between the antibody and the target organ, as for example antibodies against the acetylcholine receptor in myasthenia gravis. On other occasions, especially when the antigen is intracellular, the mechanism of the autoantibody reaction is not known. Finally, in a third group, the antibody associated with a particular paraneoplastic neurological alteration has not been identified. In this paper we describe the main paraneoplastic neurological pictures and known antibodies, including the molecular aspects and the neoplasias most frequently related to them.

Laminitis as a Systemic Disease

This article presents the clinical pathology and the involvement of the cardiovascular, renal, endocrine, and immunologic systems in laminitis. The data available on these systems are presented with respect to the disease phase and severity. The nutritional and metabolic alterations realized in the chronically affected horse are also presented. In this discussion, the origins and clinical implications of these systemic findings are discussed.

The influence of nutritional and metabolic status on progression from asymptomatic HIV infection to AIDS-defining diagnosis.

Changes in body weight and lean tissue increase morbidity and mortality during AIDS; however there are few data on the effect of alterations in nutrition and metabolism on disease progression at earlier stages of HIV infection. To assess whether change in weight, lean tissue or skeletal muscle affects progression to AIDS; to assess prospectively the effects of recognized alterations in nutrition and metabolism in asymptomatic HIV-seropositive men on disease progression; and to examine prospectively changes in nutrition and metabolism at AIDS-defining diagnosis. A group of 104 asymptomatic HIV-seropositive men were recruited and prospectively examined at 3-monthly intervals between April 1993 and September 1995. Nutritional status and metabolism were examined using indirect calorimetry, dual energy X-ray absorptiometry and urine excretion of simple sugars. Time-fixed and time-dependent Cox's proportional hazard models were fitted to calculate risks of developing a first AIDS diagnosis, weight loss or death. During the study period, 31 subjects had a first AIDS diagnosis of whom 26 were fully assessed. Changes in nutrition and metabolism do not affect disease progression in asymptomatic HIV infection. However, subjects with a reduction in body weight and basal metabolic index tend to have a higher risk of progression to AIDS-defining diagnosis, independent of CD4 count. There is a significant decrease in all body tissue compartments, a decrease in excretion of urinary sugars and significant increase in resting energy expenditure and fat oxidation associated with a first AIDS diagnosis. Change in metabolic and nutritional status at the asymptomatic stage of HIV infection does not influence disease progression significantly, although there is a trend suggesting weight loss has an independent effect on outcome. There is a cachectic response to AIDS-defining opportunistic infection or tumour.

Toxicity of a particulate formulation for the intraperitoneal application of mitoxantrone

Mitoxantrone (MXN) has demonstrated therapeutic efficacy in the intraperitoneal treatment of malignancies. However, severe local toxicity is dose limiting. Therefore, a particulate formulation of MXN, the drug incorporated in albumin microspheres, was evaluated concerning tolerability. Survival rates as well as alterations in body weight, food intake, water intake, urine volume, urine specific gravity, urine protein content, and complete blood count were observed following single or multiple intraperitoneal injections of MXN solution, dispersions containing MXN-loaded microspheres or unloaded microspheres, and the injection vehicle to female and male Sprague–Dawley rats. Applied MXN dosage was equivalent to 30 mg/m 2 body surface area. Unloaded microspheres were well tolerated without signs of toxicity. Application of MXN solution or MXN-loaded microspheres resulted in similar survival rates (56% 9 weeks after single injection) and in a comparable bone marrow toxicity (mainly leucopenia). Body weight, food and water intake as well as urine volume were decreased following application of MXN solution, whereas a progressive gain in weight and no remarkable alterations in nutrition and urine excretion were noted after administration of MXN-loaded and unloaded microspheres, or of the injection vehicle. In conclusion, intraperitoneal injection of MXN incorporated in albumin microspheres exhibits in part less toxicity than conventional treatment.

USE OF INDIGENOUS EXPLANATIONS AND REMEDIES TO FURTHER UNDERSTAND NAUSEA AND VOMITING DURING PREGNANCY

Professional and indigenous midwives are rich and appropriate sources of information about antenatal comfort measures. Midwives from a variety of geographic and cultural areas were interviewed to further our understanding of the phenomenon of nausea and vomiting during pregnancy (NVP). The midwives offered general physiological, psychological, and socioeconomic etiological theories that were, at times, inconsistent with their recommended remedies. The remedies generally included alterations in maternal nutrition, activity, and environment. Commonalities in the midwives theories of etiology and treatment were found across culturally and geographically diverse groups. Much of the variation that was noted in the midwives recommendations for treatment was related to (a) availability of a specific remedy and (b) the midwife's willingness to either support or discourage intuitive responses that women have to their pregnancies (e.g., encourage either additional rest or exercise and productive activity; social withdrawal or usual social interaction; and pica and food cravings or a balanced diet with high nutritive value).

Interventional nutrition for cardiac disease

Animals with cardiac disease can have a variety of nutritional alterations for which interventional nutrition can be beneficial. Deviation from optimal body weight, both obesity and cachexia, is a common problem in cardiac patients and adversely affects the animal. Methods for maintaining optimal weight are important for good quality of life in dogs and cats with cardiac disease. Providing proper diets to prevent excess intake of sodium and chloride also is important, but severe salt restriction may not be necessary until later stages of disease. Certain nutrient deficiencies may play a role in the pathogenesis or complications of cardiac disease, but nutrients also may have effects on cardiac disease which are above and beyond their nutritional effects (nutritional pharmacology). Supplementation of nutrients such as taurine, carnitine, coenzyme Q10, and omega-3 polyunsaturated fatty acids may have benefits in dogs or cats with cardiac disease through a number of different mechanisms. By addressing each of these areas maintaining optimal weight, avoiding nutritional deficiencies and excesses, and providing the benefits of nutritional pharmacology, optimal patient management can be achieved.

Nutritional studies of the embryo during early organogenesis with normal embryos and embryos exhibiting yolk sac dysfunction

In 1961 we reported that heterologous kidney antiserum when injected into pregnant rats resulted in wide spectrum of congenital malformations. Further studies identified that it was the IgG component of the antiserum that was teratogenic and that complement was not necessary to produce the teratogenic effect. Labeled antibody studies demonstrated that the kidney antiserum localized in the kidney and in the visceral yolk sac (VYS) and parietal yolk sac placentas. Preparation of yolk sac (YS) antiserum proved to be more potent than the kidney antiserum. Adsorption studies with VYS and parietal yolk sac antiserum revealed that the site of the teratogenic process was located in the VYS. In vitro embryo culture experiments demonstrated that direct injection of the teratogenic antibody into the amniotic or YS cavity did not injure the embryo, thus indicating that the teratogenic antibody had to come in contact with the absorptive surface of the VYS. Collaboration with Dr. John Lloyd demonstrated that teratogenic antibody interfered with the process of pinocytosis and the delivery of amino acids (AA) to the developing embryo. Our studies into the nature of the source of AA for the embryo indicated that in some instances >95% of the AA present in the developing embryo were derived from maternal proteins and the remainder from free AA in the maternal serum. We also demonstrated that embryonic methionine was derived primarily from the digestion of maternal serum proteins but that more of the methionine was diverted from the synthesis of embryonic proteins, supporting the view that it has important functions other than the synthesis of proteins. All these studies focus on the role of the YS in human development and whether human YS dysfunction may play a role in the pathogenesis of congenital malformations. Further studies on the delivery of AA to the embryo are warranted to determine whether certain AA are in short supply in maternal serum and place the embryo at risk if nutritional alterations in the maternal environment occurs. Furthermore, the YS may be an organ whose role might offer opportunities for pregnancy control. (J Pediatr 1998;132:S6-S16.)

Mechanisms for the increase in phosphorus uptake of waterlogged plants: soil phosphorus availability, root morphology and uptake kinetics.

Waterlogging frequently reduces plant biomass allocation to roots. This response may result in a variety of alterations in mineral nutrition, which range from a proportional lowering of whole-plant nutrient concentration as a result of unchanged uptake per unit of root biomass, to a maintenance of nutrient concentration by means of an increase in uptake per unit of root biomass. The first objective of this paper was to test these two alternative hypothetical responses. In a pot experiment, we evaluated how plant P concentration of Paspalum dilatatum, (a waterlogging-tolerant grass from the Flooding Pampa, Argentina) was affected by waterlogging and P supply and how this related to changes in root-shoot ratio. Under both soil P levels waterlogging reduced root-shoot ratios, but did not reduce P concentration. Thus, uptake of P per unit of root biomass increased under waterlogging. Our second objective was to test three non-exclusive hypotheses about potential mechanisms for this increase in P uptake. We hypothesized that the greater P uptake per unit of root biomass was a consequence of: (1) an increase in soil P availability induced by waterlogging; (2) a change in root morphology, and/or (3) an increase in the intrinsic uptake capacity of each unit of root biomass. To test these hypotheses we evaluated (1) changes in P availability induced by waterlogging; (2) specific root length of waterlogged and control plants, and (3) P uptake kinetics in excised roots from waterlogged and control plants. The results supported the three hypotheses. Soil P avail-ability was higher during waterlogging periods, roots of waterlogged plants showed a morphology more favorable to nutrient uptake (finer roots) and these roots showed a higher physiological capacity to absorb P. The results suggest that both soil and plant mechanisms contributed to compensate, in terms of P nutrition, for the reduction in allocation to root growth. The rapid transformation of the P uptake system is likely an advantage for plants inhabiting frequently flooded environments with low P fertility, like the Flooding Pampa. This advantage would be one of the reasons for the increased relative abundance of P. dilatatum in the community after waterlogging periods.

Assessment of nutritional status in cancer patients: widely neglected?

Frank cachexia is usually evident in the clinical evaluation, but important metabolic alterations in tumour-bearing patients with slight weight changes are frequently overlooked. Since several factors are involved in cancer-induced malnutrition (marasmus type descriptive of general inadequate food intake, kwashiorkor type descriptive of inadequate protein intake/increased turnover), medical/dietary history and physical examination (dynamic weight loss, vitamin/mineral deficiency) should be complemented by simple additional laboratory tests. Minimal baseline testing may include: weight loss (> 5%/month = severe) and serum albumin (< 24 g/l = severe). Anthropometric measurements (triceps skin fold, midarm muscle circumference) for the assessment of fat deposits and lean body mass are rarely used in a routine clinical setting owing to great variations among individuals and interobserver measurement variability. The Prognostic Nutritional Index (PNI), including serum parameters, immune competence testing and anthropometrics (but no further dietary parameters, i.e. dynamic weight loss), has proved to be quite a reliable method of predicting postoperative morbidity/mortality and of selecting cancer patients for aggressive preoperative nutritional interventions. For clinical studies including the evaluation of nutritional status (stratification, prognostic impact) and/or outcome (nutritional interventions), a simple standardized and validated assessment protocol including dietary history, specific physical examination and widely available laboratory testing should be implemented to document significant nutritional alterations. Body weight alone will often fail to demonstrate important disease- or therapy-related changes in caloric intake or metabolic rate.

Maternal clinical factors influencing HIV-1 transmission.

The complex puzzle of maternal factors involved in mother-to-child human immunodeficiency virus type 1 (HIV-1) transmission is being put together. The risk of perinatal infection increases with mother's disease progression, but it remains stable in women seroconverting to HIV-1 during pregnancy and in consecutive pregnancies. Thus, transmission correlates with the HIV-1 progression rather than the duration of infection in the mother. Nutritional alterations such as vitamin A deficiency may also have a significant impact, whereas geographic origin and mode of maternal infection are of no influence. Placenta membrane inflammation and concurrent sexually transmitted diseases are other significant covariates. The rate of transmission appears directly correlated with maternal age and inversely with length of gestation. A protective effect of caesarean section has been reported in some observational studies but, being controversial, these results need to be corroborated by randomized trials.

Physiological effects of copper on iron acquisition processes in Plantago

SUMMARYIn Plantago lanceolata L. the effect of Cu(II) additions to the nutrient solution on root‐associated Fe(III) reductase was studied in a factorial design with different Cu(II) and Fe(III) concentrations. Iron starvation resulted in approx. an eightfold increase in root Fe reduction at the level of intact plants and twofold enhancement in the specific activity of both NADH‐linked FeEDTA reductase and H+‐ATPase in isolated root plasma membrane vesicles. In plants exposed to low (0.3–0.7 μM.) Cu and suboptimal Fe levels, reduction activity at the root surface was further increased and associated with more severe interveinal chlorosis than plants grown in Cu‐free medium. In Fe‐sufficient plants, withholding Cu over a prolonged period slightly enhanced the reduction activity.Addition of high (5 μM) Cu concentrations to Fe‐free medium inhibited the induction of the physiological responses by Fe‐deficiency stress. In plants without Fe supply but with adequate Cu supply, short‐term application of 5 μM CuSO4 completely inhibited the reduction activity. Neither incubation of the plasma membrane vesicles before measurement nor incubation of intact plants with Cu before isolation caused a significant decrease in reductase activity. The results are interpreted as indicating different mechanisms underlying Cu‐induced alterations in iron nutrition.

Low doses of insulin-like growth factor-I improve nitrogen retention and food efficiency in rats with early cirrhosis

Background/Aims: In order to ascertain whether malnutrition is an early-onset feature of liver cirrhosis and whether the anabolic hormone insulin-like growth factor I (IGF-I) could be useful in the treatment of this complication, we analyzed the nutritional alterations present in rats with early-stage liver cirrhosis and the effects of IGF-I on nutritional parameters in these animals. Methods: After a 24 h fast, a 15N-enriched diet was administered for 5 days to normal control rats and to cirrhotic rats receiving subcutaneous injections of vehicle (Group 1) or IGF-I, 2 μg·100 g bw −1·day −1, (Group 2) during the 5 experimental days. 15N, a stable N isotope, was measured in biological samples by mass spectrometry. Results: Compared with control rats, Group 1 animals showed significant reductions in N intake and food efficiency ( p<0.05, both). In addition, the weight of the gastrocnemius muscle, its total N content and the dietary N content of this muscle were significantly lower in Group 1 than in control animals ( p<0.05, all). In rats from Group 2, mean values of N intake, food efficiency, gastrocnemius N content and the amount of dietary N incorporated into this muscle were similar to those in control rats, and (with the exception of gastrocnemius N total content) significantly higher than those in non-treated cirrhotic rats ( p<0.05, all). Conclusions:A variety of nutritional disturbances were detected in rats from the early stages of liver cirrhosis. Low doses of IGF-I were found to reverse most of these changes. These results stimulate further studies to determine whether IGF-I might be useful in the correction of the malnutrition present in patients with liver cirrhosis.

Alterations in the mineral nutrition of pea seedlings exposed to cadmium

Abstract A study was made of the effects of different levels of cadmium (Cd) in the nutrient solution (0.0, 1.5, and 6.0 mg/L Cd) on the assimilation of nitrate (NO3 ‐) and the uptake and distribution of cationic nutrients in pea (Pisum sativum cv. Argona) seedlings. Cadmium treatment resulted in an accumulation of NO3 ‐ in the root, indicating an alteration in NO3 ‐ translocation to the shoot. This was related to a decrease in the nitrate reductase (NR) activity in the shoot, severely inhibiting NO3 ‐ assimilation, and associated to a reduction in fresh tissue weight and in their relative water content. The concentration of potassium (K) decreased in both root and shoot, but its relative distribution between those tissues was not affected by the presence of Cd. Among other cationic nutrients, manganese (Mn) was the most affected, its concentration constantly decreased concomitantly with the increase in Cd supply. The distribution of Mn between shoot and root revealed that more was accumulated in the shoo...

Ethanol in utero induces epithelial cell damage and altered kinetics in the developing rat intestine.

The effect of prenatal ethanol exposure on the intestinal maturation of rat fetuses was investigated to understand the nutritional alterations found in the offspring of alcoholic mothers. Female Wistar rats were maintained on solid diet and 25% ethanol solution as drinking fluid during pregnancy, and non-alcoholic isocaloric pregnant mothers were used as controls. At birth, intestines from unsuckled pups were removed for study. The weight and length of the intestine decreased significantly when ethanol was present in utero. Ultrastructural evaluation of the epithelium revealed loss of contact between neighboring enterocytes and abnormal dilation of the cisternae of the Golgi apparatus in ethanol-exposed pups. Further, increased lysosome-like vesiculation and enhanced lysosomal beta-galactosidase activity was observed in these neonates. The total number of absorptive enterocytes in the epithelium was reduced by 30% in ethanol-exposed neonates as compared to controls, due to altered cell growth and death during fetal life. Ethanol in utero stimulated epithelial cell migration which compensated cell loss, as demonstrated by 5'-Bromodeoxyuridine labeling. These findings could have important implications for the assimilation of nutrients and failure to thrive in infants with fetal alcohol syndrome.