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Query: UMLS:C0032285 (pneumonia)
 54,520 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have previously shown that retinol pretreatment limits the amount of pulmonary injury caused by 1-nitronaphthalene in male Sprague-Dawley rats. The main objective of this study was to determine if retinol pretreatment can protect the lung from the toxicity of other systemic pneumotoxicants. Furthermore because retinol has been shown to alter the hepatotoxicity of several chemicals, a secondary objective was to evaluate its effects on the liver injury caused by these toxicants. Rats were pretreated with all-trans-retinol (75 mg/kg/day, p.o.) for 1 week, and given 2-nitronaphthalene (200 mg/kg, i.p.) or paraquat (25 mg/kg, i.p.). At 24 h after 2-nitronaphthalene treatment, pulmonary morphological changes associated with the bronchiolar epithelium, as well as a moderate pneumonitis were observed. Pretreatment of rats with retinol inhibited the majority of 2-nitronaphthalene-induced pulmonary damage including the infiltration of inflammatory cells and associated edema. However, these animals possessed limited lesions associated with their non-ciliated bronchiolar epithelial (Clara) cells. Interestingly, pretreatment with retinol also caused a significant potentiation of 2-nitronaphthalene-induced liver damage. The potentiated hepatotoxicity consisted of centrilobular hepatocyte necrosis with infiltration of inflammatory cells. Gadolinium chloride (GdCl3), an inhibitor of Kupffer cell function, significantly decreased the potentiated hepatocellular injury. In paraquat-treated rats focal areas of damage to the alveolar parenchyma, consisting of inflammatory cell infiltration and alveolar sac remodeling, were observed at 48 h. Pretreatment with retinol caused significant protection from the pulmonary damaged caused by paraquat. Specifically, there was a lack of alveolar parenchymal cell damage and inflammatory cell infiltration in these animals. From these experiments, we conclude that retinol pretreatment decreases the severity of 2-nitronaphthalene and paraquat-induced pulmonary toxicity, apparently by inhibiting the inflammatory responses associated with the progression of toxic injury. In the liver, retinol potentiated 2-nitronaphthalene-induced hepatotoxicity by a mechanism which directly involves Kupffer cells.
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PMID:Modulation of chemical-induced lung and liver toxicity by all-trans-retinol in the male Sprague-Dawley rat. 857 61

To study the possible relationship between vitamin A status and the severity of pneumonia, an analysis was made of serum retinol levels, conjunctival cytology, and clinical severity of the disease in 178 children admitted to a pediatric hospital in Havana for acute infectious pneumonia. The pneumonia was considered to be complicated (n = 57) when the patient presented pleural discharge, pulmonary abscesses, or both; if not, it was considered uncomplicated (n = 121). Serum retinol values in both groups were similar and were not found to be associated with the severity of the pneumonia. On the other hand, children with alterations in conjunctival cytology were twice as likely to have complicated pneumonia as those with normal cytology (relative risk = 2.2, with a 95% confidence interval of 1.1 to 4.5).
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PMID:[Vitamin A, conjunctival cytology and clinical complications in children hospitalized with pneumonia]. 896 65

Vitamin A deficiency is a major public health problem in the countries of the Sahel. It causes xerophthalmia and high rates of child mortality and it occurs mostly in underdeveloped regions. People of all ages may suffer from vitamin A deficiency but it is a particular problem in pre-school-age children. Each year, about 250,000 children throughout the world become blind due to vitamin A deficiency. Measles, pneumonia and diarrhea reduce the child's reserves of retinol and increase the dietary requirement for vitamin A. Improvement of social conditions is a radical approach to preventing vitamin A deficiency. Three strategies are currently in use: horticultural activities and health education; fortification of food products; distribution of high-dose vitamin A capsules.
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PMID:[Strategies to control vitamin A deficiency]. 964 44

Vitamin A deficiency and acute lower respiratory tract infections coexist as important public health problems in many developing countries. We carried out a randomized, double-blind, placebo-controlled trial to examine whether large doses of vitamin A given to Tanzanian children who are admitted to the hospital with nonmeasles pneumonia would reduce the severity of respiratory disease. Six hundred eighty-seven children were randomly assigned to receive either placebo or vitamin A [200 000 IU (60 mg retinol equivalents) for children > 1 y of age and 100000 IU (30 mg retinol equivalents) for infants] on the day of admission and another dose on the following day. Of the 346 children in the vitamin A group, 13 died in the hospital, compared with 8 of 341 children in the placebo group; the relative mortality was 1.63 (95% CI: 0.67, 3.97; P = 0.28). The mean number of days of hospitalization was the same in both groups (4.2 d). There were no differences between the vitamin A and placebo groups in the duration of hospital stay when examined within categories of children stratified by age, sex, breast-feeding status, nutritional status at baseline, or quartile of dietary vitamin A intake in the 4 mo before admission to the hospital. There were also no differences in the mean number of days of fever, rapid respiratory rate, or hypoxia, whether these endpoints were examined in the total number of subjects or in a subset with more severe clinical conditions at baseline. Large doses of vitamin A had no protective effect on the course of pneumonia in hospitalized Tanzanian children.
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PMID:Vitamin A supplementation and severity of pneumonia in children admitted to the hospital in Dar es Salaam, Tanzania. 966 91

Vitamin A supplementation during acute pneumonia has not improved recovery in most human clinical trials. We hypothesize that high vitamin A intake may decrease the production of T-helper type-1 (Th1) cytokines and thereby inhibit antiviral responses. Such decreases might impair recovery from viral respiratory infections. We thus examined the effect of three interventions on viral pneumonia: 1) a high level vitamin A [250,000 IU/kg diet or 75,000 retinol equivalents (RE)/kg], or 2) control diet (4000 IU/kg diet or 1200 RE/kg) given before and during infection, and 3) initiating the high level diet upon infection to simulate the adjuvant therapy used in clinical trials. No difference was seen among the interventions in severity of disease (weight loss, lung virus titers and survival). However, both the high level diet group and the group in which vitamin A was increased at the time of infection had greater salivary immunoglobulin (Ig)A responses (geometric means, 166 and 105 microg/L, respectively) than did the control group (59 microg/L) (P = 0.0019). In contrast, the serum IgG response was higher in the control group (324+/-158 mg/L) than in the high level group (225+/-95 mg/L) (P = 0.028), although it did not differ from the group in which the diet was changed upon infection (230+/-163 mg/L) (P = 0.084). The production of interferon-gamma (IFN-gamma), a Th1 cytokine, was lower in the high level diet group (median, 0.153 microg/L) compared with the control group (median, 0.839 microg/L) (P = 0.014), whereas the production of interleukin-10 (IL-10), a Th2 cytokine, was higher with the high level diet (median, 0.304 microg/L) than with the control (median, 0.126 microg/L) (P = 0.022). This change in the Th1/Th2 pattern was not sufficient to affect recovery from viral pneumonia but may account for the increased IgA and decreased IgG responses seen with high level dietary vitamin A in this study. These data reinforce the lack of utility of vitamin A in treating acute pneumonia in children and suggest that high dose vitamin A supplements may enhance Th2-mediated immune responses, which are particularly beneficial in the case of extracellular bacterial and parasitic infections and IgA-mediated responses to mucosal infections.
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PMID:High-level dietary vitamin A enhances T-helper type 2 cytokine production and secretory immunoglobulin A response to influenza A virus infection in BALB/c mice. 1080 9

We investigated the effects of various types of dietary fat of plant and animal origin on beta-carotene absorption and tissue accumulation in rats. Rats were fed 1 mL of butter fat, lard, tallow, sunflower, arachidonic, soya, olive, or linseed oil containing 175 mg beta-carotene/mL fat by gavage, twice a week for 4 weeks. The beta-carotene and vitamin A levels in plasma and tissues were determined by rp-HPLC. The highest levels of absorbed beta-carotene were observed in the liver of animals fed olive and arachidonic oil (p < 0.001), and in the lungs of animals fed sunflower oil. Histomorphological studies showed that the observed highly variable accumulation of beta-carotene in lung tissue was most probably due to an endogenously caused lipid pneumonia. No beta-carotene was observed in blood plasma, kidney, and spleen in any group. Plasma vitamin A levels (retinol) were increased with tallow, olive, and arachidonic oil (p < 0.05). The most obvious influence was found for vitamin A in the spleen. Levels in rats fed tallow (p < 0.05), butter, or lard (p < 0.001) were higher than in controls. The lowest vitamin A levels were found in rats fed fat of plant origin. Our results suggest that the type of dietary fat can modulate the absorption of beta-carotene as well as the distribution of vitamin A in plasma and selected tissues.
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PMID:Plasma and tissue concentrations of beta-carotene and vitamin A in rats fed beta-carotene in various fats of plant and animal origin. 1090 13

The associations of hemoglobin, hematocrit, and packed cell volume with socioeconomic factors, malaria, human immunodeficiency virus (HIV) infection, and nutritional status were examined among 687 children admitted to hospital with pneumonia participating in a double blind, placebo-controlled trial of vitamin A supplementation. Children were randomized to receive 2 doses of vitamin A (200,000 IU) or placebo at baseline, and additional doses at 4 and 8 months after discharge from hospital. Hemoglobin levels were measured at enrollment and, on a subset of 161 children, during follow-up. At baseline, hemoglobin concentration was positively associated with the number of possessions in the household, maternal level of education and quality of water supply, and inversely related to malaria infection after controlling for potential confounding variables. Children infected with HIV experienced a significant fall in mean hemoglobin levels over time. The risk of developing severe anemia (< 7 g/dL) during follow-up was lower for children who were breastfed for longer than 18 months as compared to those with less than 6 months of breastfeeding (adjusted prevalence ratio = 0.14, 95% confidence interval [CI] = 0.02, 0.93; P = 0.04), and higher for children over two years of age as compared to 6 to 11 months-old infants (adjusted prevalence ratio = 8.11, 95% CI = 1.2, 55.8; P = 0.03). Children with repeated diagnoses of malaria had 4.1 times the risk of developing severe anemia than did children without the diagnosis (95% CI = 1.3, 13.5; P = 0.02). Vitamin A supplements were associated with an overall nonsignificant reduction of 14% in the risk of developing severe anemia (adjusted prevalence ratio = 0.86, 95% CI = 0.37, 1.99; P = 0.73). We conclude that malaria, HIV infection, low socioeconomic status, and short duration of breastfeeding are strong and independent determinants of adverse hematologic profiles in this population.
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PMID:Vitamin A supplementation and other predictors of anemia among children from Dar Es Salaam, Tanzania. 1128 70

Increasing data link micronutrient deficiencies to excess childhood morbidity and mortality, and similar relationships have been noted in the study of nutrition and HIV infection. We review epidemiologic studies that have examined the relationship between micronutrient deficiencies and health outcomes in childhood and HIV infection, as well as clinical trials of micronutrient supplementation. Vitamin A supplementation among communities at risk of deficiency effectively reduces mortality and morbidity in children younger than age 5, and vitamin A may be especially effective in HIV-infected children. Vertical transmission of HIV has not to date been affected by maternal micronutrient supplementation. In children with poor dietary zinc intake and/or bioavailability, zinc supplementation reduces the incidence and severity of diarrheal diseases, as well as the occurrence of pneumonia. Vitamin A therapy has not been associated with improved growth, whereas some trials have shown that zinc supplementation is associated with greater increments in height. Further trials of micronutrient supplementation are warranted.
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PMID:Micronutrients and child health: studies in international nutrition and HIV infection. 1172 Mar 41

Public health and social policies at the population level (e.g., oral rehydration therapy and immunization) are responsible for the major reduction in infant mortality worldwide. The gap in infant mortality rates between developing and developed regions is much less than that in maternal mortality rates. This indicates that maternal and child health (MCH) programs and women's health care should be combined. Since 1950, 66% of infant deaths occur in the 1st 28 days, indicating adverse prenatal and intrapartum events (e.g., congenital malformation and birth injuries). Infection, especially pneumonia and diarrhea, and low birth weight are the major causes of infant mortality worldwide. An estimated US$25 billion are needed to secure the resources to control major childhood diseases, reduce malnutrition 50%, reduce child deaths by 4 million/year, provide potable water and sanitation to all communities, provide basic education, and make family planning available to all. This cost for saving children's lives is lower than current expenditures for cigarettes (US$50 billion in Europe/year). Vitamin A supplementation, breast feeding, and prenatal diagnosis of congenital malformations are low-cost strategies that can significantly affect infant well-being and reduce child mortality in many developing countries. The US has a higher infant mortality rate than have other developed countries. The American College of Obstetricians and Gynecologists and the US National Institutes of Health are focusing on prematurity, low birth weight, multiple pregnancy, violence, alcohol abuse, and poverty to reduce infant mortality. Obstetricians should be important members of MCH teams, which also include traditional birth attendants, community health workers, nurses, midwives, and medical officers. We have the financial resources to allocate resources to improve MCH care and to reduce infant mortality.
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PMID:Reducing infant mortality. 1228 45

Dr. Nils Daulaire, senior health adviser to the US Agency for International Development (USAID), announced their plan to supplement basic food products with vitamin A which will save millions of children in Third World countries from death and diseases. Vitamin A testing conducted in Nepal and Indonesia resulted to significant reductions in the rate of childhood death. Aside from reducing the death rates from illnesses such as pneumonia, diarrhea, and malaria, vitamin A also decreases the severity of the symptoms. In recognition of these benefits, USAID and other major food and drug companies will soon begin their first vitamin A fortification and distribution projects in India, Nicaragua, and Bangladesh. The plan will also be initiated in Zambia on May 13 with a program to fortify sugar. The US government will allocate $25 million for child survival programs.
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PMID:Vitamin A: lifesaver for the Third World. AID, private sector to bring it. 1232 6


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