Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0024523 (malabsorption)
 7,319 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This article reviews current literature on the role of micronutrients in human immunodeficiency virus (HIV) infection. Deficiencies of micronutrients are common in HIV-infected persons. They occur due to malabsorption, altered metabolism, gut infection, and altered gut barrier function. There is a compelling association of deficiencies of micronutrients in HIV-infection with immune deficiency, rapid disease progression, and mortality. Also, there is increased risk of vertical HIV transmission from mother to child with deficiency of vitamin A, and of neurological impairment with vitamin B12. The last five years have been exciting in micronutrient research, and there is promise that some micronutrients may be key factors in maintaining health in HIV immunodeficiency, and in reducing mortality. Selenium appears important in reducing virulence of HIV and slowing disease progression. Vitamin A supplementation in pregnant women with HIV may reduce maternal mortality and improve birth outcomes. Supplementation in children with HIV may accelerate growth. Carotenoid supplementation is being evaluated. Vitamin B12 may slow HIV immune deficiency disease progression, and reverse neurological compromise. Clinical benefit of supplementation with some micronutrients may be measurable in the presence of pre-existing deficiency. Apart from improved general nutrition, the impact of micronutrient supplements on health and their optimal use in HIV infection is controversial because there are so few controlled clinical trials. Further research is needed to elucidate the role of micronutrient deficiencies on the course of HIV infection, and the preventive and therapeutic role of supplementation in its clinical management. Nevertheless, current knowledge supports the use of routine multivitamin and trace element supplementation as adjuvant to conventional antiretroviral drug treatment as a relatively low-cost intervention.
 ...
PMID:A clinical review of micronutrients in HIV infection. 1294 78

The objective of the present study was to identify the factors which contribute to the appearance and/or aggravation of Vitamin A Deficiency (VAD) in individuals with morbid obesity in the pre- and postoperative stages of Roux-en-Y gastric bypass (RYGBP). Bibliography searches were done in the data-bases of Medline and Lilacs, published in the last 35 years, priorizing the studies which assessed VAD through serum levels of retinol. The principal factors identified as contributors to VAD were oxidative stress, deficiency of other nutrients, lipid malabsorption in the postoperative stage, insufficient intake of lipids and food sources of Vitamin A, and presence of nonalcoholic fatty liver disease. The investigation of the nutritional status of Vitamin A in those individuals may foment intervention strategies easily incorporated in already established routine procedures, aiming to reduce VAD rates, which will reflect upon those individuals' quality of life.
 ...
PMID:Nutritional status of vitamin A in morbid obesity before and after Roux-en-Y gastric bypass. 1789 59

H. pylori is a gram-negative pathogen, etiologically associated with atrophic and non-atrophic gastritis, peptic ulcer, primary gastric B-cell lymphoma and gastric carcinoma. Several observations demonstrated a correlation between H. pylori and malabsorption of essential nutrients; epidemiological studies have shown an association between H. pylori infection and iron deficiency anemia, while the absorption of some vitamins such as vitamin B12, vitamin A, vitamin C, folic acid and Vitamin E may be affected by the infection. The main mechanism related to malabsorption of this components is the modified intragastric pH (hypo- achlorhydria) due to H. pylori infection. Moreover H. pylori is also able to determine a modification of gastrointestinal hormones by reducing plasma levels of ghrelin and increasing those of leptin and gastrin, thus affecting appetite and promoting the occurrence of dyspeptic symptoms. On the other hand, H. pylori eradication has been shown to improve serum level of iron and vitamin B12, has some effects on Vitamin A and Vitamin E absorption and has a late effects on ghrelin levels. As a consequence of those effects, H. pylori is also associated with childhood malnutrition in developing countries either for the occurrence of malabsorption or for an increased susceptibility to enteric infections caused by hypochlorhydria.
 ...
PMID:Nutritional aspects of Helicobacter pylori infection. 2210 25

Short bowel (SB) syndrome causes the malabsorption of various nutrients. Among these, vitamin A is important for a number of physiological activities. Vitamin A is absorbed by epithelial cells of the small intestine and is discharged into the lymphatic vessels as a component of chylomicrons and is delivered to the liver. In the present study, we used a rat model of SB syndrome in order to assess its effects on the expression of genes associated with the absorption, transport and metabolism of vitamin A. In the rats with SB, the intestinal mRNA expression levels of cellular retinol-binding protein II (CRBP II, gene symbol Rbp2) and apolipoprotein A-IV (gene symbol Apoa4) were higher than those in the sham-operated rats, as shown by RT-qPCR. Immunohistochemical analysis revealed that absorptive epithelial cells stained positive for both CRBP II and lecithin retinol acyltransferase, which are both required for the effective esterification of vitamin A. In the rats with SB, the retinol content in the ileum and the retinyl ester content in the jejunum were lower than those in the sham-operated rats, as shown by quantitative analysis of retinol and retinyl esters by high performance liquid chromatography. These results suggest that the elevated mRNA expression levels of Rbp2 and Apoa4 in the rats with SB contribute to the effective esterification and transport of vitamin A.
 ...
PMID:Massive bowel resection upregulates the intestinal mRNA expression levels of cellular retinol-binding protein II and apolipoprotein A-IV and alters the intestinal vitamin A status in rats. 2558 92

Vitamin A is a fundamental micronutrient that regulates various cellular patterns. Vitamin A deficiency (VAT) is a worldwide problem and the primary cause of nocturnal blindness especially in low income countries. Cystic fibrosis (CF) is a known risk factor of VAD because of liposoluble vitamin malabsorption due to pancreatic insufficiency. We describe a case of a 9-year-old girl who experienced recurrent episodes of nocturnal blindness due to profound VAD. This little girl is paradigmatic for the explanation of the key role of the gut-liver axis in vitamin A metabolism. She presents with meconium ileus at birth, requiring intestinal resection that led to a transient intestinal failure with parenteral nutrition need. In addition, she suffered from cholestatic liver disease due to CF and intestinal failure-associated liver disease. The interaction of pancreatic function, intestinal absorption and liver storage is fundamental for the correct metabolism of vitamin A.
 ...
PMID:Night Blindness in Cystic Fibrosis: The Key Role of Vitamin A in the Digestive System. 3141 57

Vitamin A (VA) is an essential nutrient often lacking in the diets of people in developing countries. Accurate biomarkers of VA status are vital to inform public health policy and monitor interventions. The relative dose-response (RDR) and modified-RDR (MRDR) tests are semi-quantitative screening tests for VA deficiency that have been used in Demographic and Health Surveys and VA intervention studies. A systematic review and meta-analysis of sensitivity and specificity were conducted to summarize the physiological evidence to support the RDR tests as methods to assess VA status and investigate the impact of different pathological and physiological states on the tests. A total of 190 studies were screened for inclusion, with 21 studies comparing the RDR tests with the gold-standard biomarker, liver VA concentration (68% and 80% sensitivity and 85% and 69% specificity for the RDR and MRDR, respectively). Nearly all studies with VA interventions in VA-deficient populations demonstrated a response of the tests to VA intake that would be expected to improve VA status. The impacts of chronic liver disease, protein malnutrition, age, pregnancy and lactation, infection and inflammation, and various other conditions were examined in 51 studies. The RDR and MRDR tests were reported to have been used in 39 observational studies, and the MRDR has been used in at least 6 national micronutrient surveys. The RDR and MRDR are sensitive tests for determining population VA status and assessing VA interventions. Although they are robust to most physiological and pathological states, caution may be warranted when using the tests in neonates, individuals with chronic liver disease, and those with protein or iron malnutrition. Research on further improvements to the tests to increase accessibility, such as sampling breast milk instead of blood or using intramuscular doses in subjects with malabsorption, will allow wider adoption. This review was registered with PROSPERO as CRD42019124180.
 ...
PMID:Systematic Review and Meta-Analysis of the Relative Dose-Response Tests to Assess Vitamin A Status. 3313 Aug 84


<< Previous 1 2