Diarrhea and reduced levels of antiretroviral drugs: improvement with glutamine or alanyl-glutamine in a randomized controlled trial in northeast Brazil

Clofazimine pharmacokinetics in HIV-infected adults with diarrhea: Implications of diarrheal disease on absorption of orally administered therapeutics

Oral drug absorption kinetics are usually established in populations with a properly functioning gastrointestinal tract. However, many diseases and therapeutics can alter gastrointestinal physiology and cause diarrhea. The extent of diarrhea-associated impact on drug pharmacokinetics has not been quantitatively described. To address this knowledge gap, we used a population pharmacokinetic modeling approach with data collected in a phase IIa study of matched human immunodeficiency virus (HIV)-infected adults with/without cryptosporidiosis and diarrhea to examine diarrhea-associated impact on oral clofazimine pharmacokinetics. A population pharmacokinetic model was developed with 428 plasma samples from 23 HIV-infected adults with/without Cryptosporidium infection using nonlinear mixed-effects modeling. Covariates describing cryptosporidiosis-associated diarrhea severity (e.g., number of diarrhea episodes, diarrhea grade) or HIV infection (e.g., viral load, CD4+ T cell count) were evaluated. A two-compartment model with lag time and first-order absorption and elimination best fit the data. Maximum diarrhea grade over the study duration was found to be associated with a more than sixfold reduction in clofazimine bioavailability. Apparent clofazimine clearance, intercompartmental clearance, central volume of distribution, and peripheral volume of distribution were 3.71 L/h, 18.2 L/h (interindividual variability [IIV] 45.0%), 473 L (IIV 3.46%), and 3434 L, respectively. The absorption rate constant was 0.625 h-1 (IIV 149%) and absorption lag time was 1.83 h. In conclusion, the maximum diarrhea grade observed for the duration of oral clofazimine administration was associated with a significant reduction in clofazimine bioavailability. Our results highlight the importance of studying disease impacts on oral therapeutic pharmacokinetics to inform dose optimization and maximize the chance of treatment success.

The effect of glycine administration on the characteristics of physiological systems in human adults: A systematic review

Functional decline of physiological systems during ageing leads to age-related diseases. Dietary glycine increases healthy lifespan in model organisms and might decrease inflammation in humans, suggesting its geroprotective potential. This review summarises the evidence of glycine administration on the characteristics of eleven physiological systems in adult humans. Databases were searched using key search terms: 'glycine', 'adult', 'supplementation'/ 'administration'/ 'ingestion'/ 'treatment'. Glycine was administered to healthy and diseased populations (18 and 34 studies) for up to 14 days and 4 months, respectively. The nervous system demonstrated the most positive effects, including improved psychiatric symptoms from longer-term glycine administration in psychiatric populations. While longer-term glycine administration improved sleep in healthy populations, these studies had small sample sizes with a high risk of bias. Larger and long-term studies with more robust study designs in healthy populations to examine the effects of glycine administration on preventing, delaying or reversing the ageing process are warranted.

Could Immunonutrition Help in the Fight against COVID-19 in Cancer Patient?

The rapid and widespread global pandemic of 2019 coronavirus disease (COVID-19) has had unprecedented negative health and economic impacts. Immune responses play a key role in the development of COVID-19, including the disruption of immune balance and cytokine storms caused by excessive inflammatory responses. Due to the effects of cancer itself and treatment, patients often accompanied by immunosuppression appear to be a susceptible population for COVID-19. Worryingly, COVID-19 with cancer is associated with a poor prognosis. Cancer patients are a vulnerable group, threatened by COVID-19, finding a way to combat COVID-19 for them is urgent. Immunonutrition is closely related to balance and strong immune function. Supplementary immunonutrition can improve the immune function and inflammatory response of cancer patients after surgery, which provides evidence for the role of immunonutrition in combating COVID-19. We reviewed possible mechanisms of immunonutrition against COVID-19, including enhancing immune cell function, increasing immune cell count, ameliorating excessive inflammatory response, and regulating gut microbiota. Immunonutrition supplementation in cancer patients may be beneficial to enhance immune function in the early stage of COVID-19 infection and control excessive inflammatory response in the late stage. Therefore, immunonutrition is a potential strategy for the prevention and treatment of COVID-19 in cancer.

Fecal Contamination on the Household Compound and in Water Sources are Associated with Subsequent Diarrhea in Young Children in Urban Bangladesh (CHoBI7 Program)

We investigated the environmental and individual-level risk factors for diarrheal disease among young children in slum areas of Dhaka, Bangladesh. A prospective cohort study was conducted among 884 children under 5 years of age. Caregiver reports were collected on sociodemographic factors and hygiene behaviors. Diarrhea surveillance data was collected monthly based on caregiver-reported diarrhea for children in the past 2 weeks during the 12-month study period. Unannounced spot checks of the household compound were performed at 1, 3, 6, 9, and 12 months after enrollment to check for the presence of feces (animal or human) and the presence of animals in the child's sleeping space, to assess child and caregiver hands for the presence of dirt, and to collect samples of the household's source and stored drinking water. Children with feces found on the household compound during spot checks had a significantly higher odds of diarrhea (odds ratio: 1.71; 95% confidence interval: 1.23-2.38). Children residing in households with > 100 colony forming units/100 mL Escherichia coli in source drinking water had a significantly higher odds of diarrhea (OR: 1.43; 95% CI: 1.06-1.92). The presence of feces on the household compound and source drinking water with > 100 colony forming units/100 mL E. coli were significant risk factors for diarrheal disease for children < 5 years of age in slum areas of Dhaka, Bangladesh. These findings demonstrate the urgent need for comprehensive interventions to reduce fecal contamination on the household compound to protect the health of susceptible pediatric populations.

Host cell glutamine metabolism as a potential antiviral target

A virus minimally contains a nucleic acid genome packaged by a protein coat. The genome and capsid together are known as the nucleocapsid, which has an envelope containing a lipid bilayer (mainly phospholipids) originating from host cell membranes. The viral envelope has transmembrane proteins that are usually glycoproteins. The proteins in the envelope bind to host cell receptors, promoting membrane fusion and viral entry into the cell. Virus-infected host cells exhibit marked increases in glutamine utilization and metabolism. Glutamine metabolism generates ATP and precursors for the synthesis of macromolecules to assemble progeny viruses. Some compounds derived from glutamine are used in the synthesis of purines and pyrimidines. These latter compounds are precursors for the synthesis of nucleotides. Inhibitors of glutamine transport and metabolism are potential candidate antiviral drugs. Glutamine is also an essential nutrient for the functions of leukocytes (lymphocyte, macrophage, and neutrophil), including those in virus-infected patients. The increased glutamine requirement for immune cell functions occurs concomitantly with the high glutamine utilization by host cells in virus-infected patients. The development of antiviral drugs that target glutamine metabolism must then be specifically directed at virus-infected host cells to avoid negative effects on immune functions. Therefore, the aim of this review was to describe the landscape of cellular glutamine metabolism to search for potential candidates to inhibit glutamine transport or glutamine metabolism.

Intervention and Mechanisms of Alanyl-glutamine for Inflammation, Nutrition, and Enteropathy: A Randomized Controlled Trial

OBJECTIVE

Determine the minimum dosage of alanyl-glutamine (Ala-Gln) required to improve gut integrity and growth in children at risk of environmental enteropathy (EE).

METHODS

This was a double-blinded randomized placebo-controlled dose-response trial. We enrolled 140 children residing in a low-income community in Fortaleza, Brazil. Participants were 2 to 60 months old and had weight-for-age (WAZ), height-for-age (HAZ), or weight-for-height (WHZ) z-scores less than -1. We randomized children to 10 days of nutritional supplementation: Ala-Gln at 3 g/day, Ala-Gln at 6 g/day, Ala-Gln at 12 g/day, or an isonitrogenous dose of glycine (Gly) placebo at 12.5 g/day. Our primary outcome was urinary lactulose-mannitol excretion testing. Secondary outcomes were anthropometry, fecal markers of inflammation, urine metabolic profiles, and malabsorption (spot fecal energy).

RESULTS

Of 140 children, 103 completed 120 days of follow-up (24% dropout). In the group receiving the highest dose of Ala-Gln, we detected a modest improvement in urinary lactulose excretion from 0.19% on day 1 to 0.17% on day 10 (P = 0.05). We observed significant but transient improvements in WHZ at day 10 in 2 Ala-Gln groups, and in WHZ and WAZ in all Ala-Gln groups at day 30. We detected no effects on fecal inflammatory markers, diarrheal morbidity, or urine metabolic profiles; but did observe modest reductions in fecal energy and fecal lactoferrin in participants receiving Ala-Gln.

CONCLUSIONS

Intermediate dose Ala-Gln promotes short-term improvement in gut integrity and ponderal growth in children at risk of EE. Lower doses produced improvements in ponderal growth in the absence of enhanced gut integrity.

Effervescent Glutamine Formulation Improves the Beneficial Effects of Antiretroviral Therapies on Immune Function in HIV/AIDS Carrier Patients

The impact of oral supplementation with an effervescent glutamine formulation on the beneficial effects of antiretroviral therapies was evaluated in people living with HIV/AIDS. For this purpose, 12 HIV/AIDS carrier patients with CD4⁺ T cell counts <500, and who had received the same antiretroviral therapy for at least 1 year before starting this investigation were selected. The patients were required to dissolve the effervescent glutamine formulation (supplied in sachets) in water immediately before oral ingestion (12.4 g), once a day, after lunch or after dinner during 30 days. CD4⁺ T cell counts, complete blood cell counts, serum cytokines, and amino acids levels were quantified; biochemical and toxicological measurements were performed. The numbers of CD4⁺ T cells were increased (P < .05), and the serum C-reactive protein levels decreased (P < .01) after the administration of effervescent glutamine formulation. Serum levels of interferon-gamma inducible protein-10, RANTES, and macrophage inflammatory protein-1β were decreased after the treatment with effervescent glutamine formulation. No changes were observed in the serum levels of amino acids, hematological, toxicological, and biochemical parameters. In conclusion, the treatment during 30 days with effervescent glutamine formulation was well tolerated, promoted reduction of inflammation, and improved the beneficial effects of antiretroviral therapies in HIV/AIDS carrier patients.

Gut reaction: impact of systemic diseases on gastrointestinal physiology and drug absorption

It was in 400 BC that Hippocrates reportedly stated that "death sits in the colon". The growth in our knowledge of the intestinal microbiome, the gut-brain axis and their function and imbalance has distinctly uncovered the complex relationship between the gut to disease predisposition and development, heralding the problem and the solution to disease pathology. Human studies of new drug molecules are typically performed in healthy volunteers and their specific disease indication. Approved drugs, however, are used by patients with diverse disease backgrounds. Here, we review the current literature of the gastrointestinal tract reacting to systemic disease pathology that elicits physiological and functional changes that consequently affect oral drug product performance.

Water, sanitation and hygiene practice and associated factors among HIV infected people in Arba Minch town, Southern Ethiopia

Human immunodeficiency virus (HIV) infected people have substantially greater need for water, sanitation and hygiene (WASH). Many opportunistic infections cause high morbidity and mortality in people living with HIV (PLHIV) than in immune competent populations. The objective of the study was to assess WASH practices and associated factors among PLHIV. A cross-sectional study design was conducted. Bivariate and multivariate logistic model was employed. According to this study, 97 (23.5%) of the households have unimproved water status, 221 (53.5%) of the households have unimproved sanitation status and 171 (41.4%) of the households have poor hygiene practice. Diarrhoea [adjusted odds ratio (AOR) = 16; 95% confidence interval (CI): (6, 44)] was associated with water status of the clients. Occupational status [AOR = 8.9; 95% CI: (2, 38)], wealth index [AOR = 0.23; 95% CI: (0.12, 0.4)], frequency of body washing [AOR = 0.23; 95% CI: (0.12, 0.4)] and hand washing device availability [AOR = 4.4; 95% CI: (2.5, 8)] were significantly associated with hygienic practice. It was concluded that the magnitude of the problem regarding WASH practices in HIV infected people in the study area was high. Health education and integrated additional support for the provision of WASH practices is needed.

Probiotics, Soluble Fiber, and L-Glutamine (GLN) Reduce Nelfinavir (NFV)or Lopinavir/Ritonavir (LPV/r)-related Diarrhea

Purpose: Highly active antiretroviral therapy (HAART) can be associated with diarrhea and other gastrointestinal (GI) side effects. Reducing these side effects may improve treatment durability and quality of life (QOL). This study assessed the impact of nutritional co-therapies known to reduce diarrhea in HIV-positive men treated with nelfinavir (NFV)- or lopinavir/ritonavir (LPV/r)-containing regimens. Methods: Thirty-five HIV-positive men treated with NFV (n = 27) or LPV/r (n = 8) with diarrhea (± two liquid stools/day [d]) participated in a 12-week prospective study. Twenty-eight subjects were randomly assigned supplements (S), seven received standard of care (C). Group S received probiotics (1.2g/d) and soluble fiber (11g/d). If diarrhea persisted at week 4, 30g/d L-Glutamine (GLN) was added. Diarrhea incidence, as well as supplement and antidiarrheal use, was assessed monthly. Results: Weight, CD4 count, and HIV RNA were unchanged in both groups. Diarrhea completely resolved in 10 of 28 (36 percent) S subjects. The mean (± SD) number of stools/d declined [3.40 ± 1.25 to 2.54 ± 1.34 (p < 0.01)]. Diarrhea (loose, watery stools/d) lessened in S from 2.84 ± 1.42 to 0.74 ± 1.03 (p < 0.0001). Fifteen S subjects did not obtain full relief with probiotics and fiber, but stools/d decreased from 4.08 ± 1.35 to 3.06 ± 1.68 (p < 0.05) after starting GLN. In C, stools/d, 4.14 ± 4.86 to 3.44 ± 1.68(p = 0.678) and incidence of diarrhea/d, 3.00 ± 4.82 to 1.36 ± 1.29 (p= 0.361) was unchanged. In S, loperamide use decreased from 1.69 ± 2.34 to 0.31 ± 0.69 mg/d (p < 0.01); 18 versus eight subjects used loperamide at 0 and 12 weeks, respectively. Conclusion: Probiotics, soluble fiber, and GLN significantly reduced diarrhea for subjects receiving NFV or LPV/r. Nutritional co-therapies show clinical benefit in HIV-positive men with diarrhea.

The impact of water, sanitation, and hygiene interventions on the health and well-being of people living with HIV: a systematic review

BACKGROUND

Access to improved water supply and sanitation is poor in low-income and middle-income countries. Persons living with HIV/AIDS (PLHIV) experience more severe diarrhea, hospitalizations, and deaths from diarrhea because of waterborne pathogens than immunocompetent populations, even when on antiretroviral therapy (ART).

METHODS

We examined the existing literature on the impact of water, sanitation, and hygiene (WASH) interventions on PLHIV for these outcomes: (1) mortality, (2) morbidity, (3) retention in HIV care, (4) quality of life, and (5) prevention of ongoing HIV transmission. Cost-effectiveness was also assessed. Relevant abstracts and articles were gathered, reviewed, and prioritized by thematic outcomes of interest. Articles meeting inclusion criteria were summarized in a grid for comparison.

RESULTS

We reviewed 3355 citations, evaluated 132 abstracts, and read 33 articles. The majority of the 16 included articles focused on morbidity, with less emphasis on mortality. Contaminated water, lack of sanitation, and poor hygienic practices in homes of PLHIV increase the risk of diarrhea, which can result in increased viral load, decreased CD4 counts, and reduced absorption of nutrients and antiretroviral medication. We found WASH programming, particularly water supply, household water treatment, and hygiene interventions, reduced morbidity. Data were inconclusive on mortality. Research gaps remain in retention in care, quality of life, and prevention of ongoing HIV transmission. Compared with the standard threshold of 3 times GDP per capita, WASH interventions were cost-effective, particularly when incorporated into complementary programs.

CONCLUSIONS

Although research is required to address behavioral aspects, evidence supports that WASH programming is beneficial for PLHIV.

Risk factors for diarrhea in children under five years of age residing in peri-urban communities in Cochabamba, Bolivia

This study examined the relationship between childhood diarrhea prevalence and caregiver knowledge of the causes and prevention of diarrhea in a prospective cohort of 952 children < 5 years of age in Cochabamba, Bolivia. The survey of caregiver knowledge found that more than 80% of caregivers were unaware that hand washing with soap could prevent childhood diarrhea. Furthermore, when asked how to keep food safe for children to eat only 17% of caregivers reported hand washing before cooking and feeding a child. Lack of caregiver awareness of the importance of practices related to hygiene and sanitation for diarrhea prevention were significant risk factors for diarrheal disease in this cohort. The knowledge findings from this study suggest that health promotion in these communities should put further emphasis on increasing knowledge of how water treatment, hand washing with soap, proper disposal of child feces, and food preparation relate to childhood diarrhea prevention.

Zinc treatment ameliorates diarrhea and intestinal inflammation in undernourished rats

BACKGROUND

WHO guidelines recommend zinc supplementation as a key adjunct therapy for childhood diarrhea in developing countries, however zinc's anti-diarrheal effects remain only partially understood. Recently, it has been recognized that low-grade inflammation may influence stunting. In this study, we examined whether oral zinc supplementation could improve weight, intestinal inflammation, and diarrhea in undernourished weanling rats.

METHODS

Rats were undernourished using a northeastern Brazil regional diet (RBD) for two weeks, followed by oral gavage with a saturated lactose solution (30 g/kg) in the last 7 days to induce osmotic diarrhea. Animals were checked for diarrhea daily after lactose intake. Blood was drawn in order to measure serum zinc levels by atomic absorption spectroscopy. Rats were euthanized to harvest jejunal tissue for histology and cytokine profiles by ELISA. In a subset of animals, spleen samples were harvested under aseptic conditions to quantify bacterial translocation.

RESULTS

Oral zinc supplementation increased serum zinc levels following lactose-induced osmotic diarrhea. In undernourished rats, zinc improved weight gain following osmotic diarrhea and significantly reduced diarrheal scores by the third day of lactose intake (p < 0.05), with improved jejunum histology (p < 0.0001). Zinc supplementation diminished bacterial translocation only in lactose-challenged undernourished rats (p = 0.03) compared with the untreated challenged controls and reduced intestinal IL-1β and TNF-α cytokines to control levels.

CONCLUSION

Altogether our findings provide novel mechanisms of zinc action in the setting of diarrhea and undernutrition and support the use of zinc to prevent the vicious cycle of malnutrition and diarrhea.

Effectiveness of milk whey protein-based ready-to-use therapeutic food in treatment of severe acute malnutrition in Malawian under-5 children: a randomised, double-blind, controlled non-inferiority clinical trial

The cost of ready‐to‐use therapeutic food (RUTF) used in community‐based management of acute malnutrition has been a major obstacle to the scale up of this important child survival strategy. The current standard recipe for RUTF [peanut‐based RUTF (P‐RUTF)] is made from peanut paste, milk powder, oil, sugar, and minerals and vitamins. Milk powder forms about 30% of the ingredients and may represent over half the cost of the final product. The quality of whey protein concentrates 34% (WPC34) is similar to that of dried skimmed milk (DSM) used in the standard recipe and can be 25–33% cheaper. This blinded, parallel group, randomised, controlled non‐inferiority clinical trial tested the effectiveness in treating severe acute malnutrition (SAM) of a new RUTF formulation WPC‐RUTF in which WPC34 was used to replace DSM. Average weight gain (non‐inferiority margin Δ = −1.2 g kg⁻¹ day⁻¹) and recovery rate (Δ = −10%) were the primary outcomes, and length of stay (LOS) was the secondary outcome (Δ = +14 days). Both per‐protocol (PP) and intention‐to‐treat (ITT) analyses showed that WPC‐RUTF was not inferior to P‐RUTF for recovery rate [difference and its 95% confidence interval (CI) of 0.5% (95% CI –2.7, 3.7) in PP analysis and 0.6% (95% CI –5.2, 6.3) in ITT analysis] for average weight gain [0.2 (−0.5; 0.9) for both analyses] and LOS [−1.6 days (95% CI, −4.6, 1.4 days) in PP analysis and −1.9 days (95% CI, −4.6, 0.8 days) for ITT analysis]. In conclusion, whey protein‐based RUTF is an effective cheaper alternative to the standard milk‐based RUTF for the treatment of SAM.

Unexpected vertical transmission of HIV infection

Mother-to-child transmission of HIV infection occurred in a child born from an HIV-infected mother with HIV-RNA undetectable during pregnancy. She was suffering from gastroenteritis in the last 3 weeks of gestation.

IMPROVEMENT OF INTESTINAL PERMEABILITY WITH ALANYL-GLUTAMINE IN HIV PATIENTS:

ContextGlutamine is the main source of energy of the enterocyte and diarrhea and weight loss are frequent in HIV infected patients.ObjectiveTo determine the effect of alanyl-glutamine supplementation on intestinal permeability and absorption in these patients.MethodsRandomized double-blinded, placebo-controlled study using isonitrogenous doses of alanyl-glutamine (24 g/day) and placebo (glycine, 25 g/day) during 10 days. Before and after this nutritional supplementation lactulose and mannitol urinary excretion were determined by high performance liquid chromatography.ResultsForty six patients with HIV/AIDS, 36 of whom were male, with 37.28 ± 3 (mean ± standard error) years were enrolled. Twenty two and 24 subjects were treated with alanyl-glutamine and with glycine respectively. In nine patients among all in the study protocol that reported diarrhea in the 14 days preceding the beginning of the study, mannitol urinary excretion was significantly lower than patients who did not report this symptom [median (range): 10.51 (3.01–19.75) vs. 15.37 (3.93–46.73); P = 0.0281] and lactulose/mannitol ratio was significantly higher [median (range): 0.04 (0.00–2.89) vs. 0.02 (0.00–0.19); P = 0.0317]. There was also a significant increase in mannitol urinary excretion in the group treated with alanyl-glutamine [median (range): 14.38 (8.25–23.98) before vs 21.24 (6.27–32.99) after treatment; n = 14, P = 0.0382].ConclusionOur results suggest that the integrity and intestinal absorption are more intensely affected in patients with HIV/AIDS who recently have had diarrhea. Additionally, nutritional supplementation with alanyl-glutamine was associated with an improvement in intestinal absorption.

Protective effects of alanyl-glutamine supplementation against nelfinavir-induced epithelial impairment in IEC-6 cells and in mouse intestinal mucosa

PURPOSE

Human Immunodeficiency Virus (HIV) protease inhibitors (PI) remain a crucial component of highly active therapy (HAART) and recently have been demonstrated to have potent antitumor effect on a wide variety of tumor cell lines. However, discontinuation of therapy is an important issue, which may be related to various side-effects, especially diarrhea. The aim of this study was to evaluate the effects of nelfinavir (NFV), an HIV PI, and of alanyl-glutamine (AQ) supplementation, on intestinal cell migration, proliferation, apoptosis and necrosis, using IEC-6 cells and on intestinal crypt depth, villus length, villus area, mitotic index and apoptosis in Swiss mice.

METHODS

Migration was evaluated at 12 and 24 h after injury using a wound healing assay. Cellular proliferation was measured indirectly at 24 and 48 h using tetrazolium salt WST-1. Apoptosis and necrosis were measured by flow cytometry using the Annexin V assay. Intestinal morphometry and mitotic index in vivo were assessed following a seven-day treatment with 100 mg/kg of NFV, given orally. In vivo proliferation and apoptosis were evaluated by intestinal crypt mitotic index and immunohistochemistry, respectively.

RESULTS

In vitro, AQ supplementation enhanced IEC-6 cell migration and proliferation, following challenge with NFV. In vivo, AQ increased intestinal villus length, villus area, crypt depth and cell proliferation and cell migration, following treatment with NFV. AQ did not decrease cell death induced by NFV both in vivo and in vitro.

CONCLUSIONS

AQ supplementation is potentially beneficial in preventing the effects of PIs, such as NFV, in the intestinal tract.

Goat milk with and without increased concentrations of lysozyme improves repair of intestinal cell damage induced by enteroaggregative Escherichia coli

BACKGROUND

Enteroaggregative Escherichia coli (EAEC) causes diarrhea, malnutrition and poor growth in children. Human breast milk decreases disease-causing bacteria by supplying nutrients and antimicrobial factors such as lysozyme. Goat milk with and without human lysozyme (HLZ) may improve the repair of intestinal barrier function damage induced by EAEC. This work investigates the effect of the milks on intestinal barrier function repair, bacterial adherence in Caco-2 and HEp-2 cells, intestinal cell proliferation, migration, viability and apoptosis in IEC-6 cells in the absence or presence of EAEC.

METHODS

Rat intestinal epithelial cells (IEC-6, ATCC, Rockville, MD) were used for proliferation, migration and viability assays and human colon adenocarcinoma (Caco-2, ATCC, Rockville, MD) and human larynx carcinoma (HEp-2, ATCC, Rockville, MD) cells were used for bacterial adhesion assays. Goats expressing HLZ in their milk were generated and express HLZ in milk at concentration of 270 μg/ml. Cells were incubated with pasteurized milk from either transgenic goats expressing HLZ or non-transgenic control goats in the presence and absence of EAEC strain 042 (O44:H18).

RESULTS

Cellular proliferation was significantly greater in the presence of both HLZ transgenic and control goat milk compared to cells with no milk. Cellular migration was significantly decreased in the presence of EAEC alone but was restored in the presence of milk. Milk from HLZ transgenic goats had significantly more migration compared to control milk. Both milks significantly reduced EAEC adhesion to Caco-2 cells and transgenic milk resulted in less colonization than control milk using a HEp-2 assay. Both milks had significantly increased cellular viability as well as less apoptosis in both the absence and presence of EAEC.

CONCLUSIONS

These data demonstrated that goat milk is able to repair intestinal barrier function damage induced by EAEC and that goat milk with a higher concentration of lysozyme offers additional protection.

Novel in vitro and in vivo models and potential new therapeutics to break the vicious cycle of Cryptosporidium infection and malnutrition

BACKGROUND

Although several animal models of cryptosporidiosis have been reported, most involve genetically or pharmacologically immune-suppressed hosts.

METHODS

We report challenge with excysted (in vitro and in vivo) and unexcysted (in vivo) Cryptosporidium parvum oocysts in human colonic adenocarcinoma (HCT-8) cells and weaned nourished and malnourished C57BL/6 mice, following outcomes of growth rate, stool shedding, and tissue burden. We tested treatment with an oligodeoxynucleotide containing unmethylated CpG motif (CpG-ODN) and alanyl-glutamine in vivo and in vitro.

RESULTS

C. parvum-challenged mice showed prolonged weight loss (>10% over 4 days), robust stool shedding (>3 logs/d over 7 days), and epithelial infection in the ileum, cecum, and colon. Of 2 potential therapeutic compounds evaluated in the model, CpG-ODN reduced body weight loss (to <6% on days 3-7 after challenge), reduced shedding of organisms (by 25% on days 1 and 3 after challenge), and decreased the burden of parasites in the ileum. Alanyl-glutamine showed similar benefits. In vitro findings suggested that effects on the epithelial component of the mucosa probably likely responsible for beneficial effects seen in vivo.

CONCLUSIONS

Weaned mice provide a convenient and reproducible model of cryptosporidial disease, including its vicious cycle with body weight loss and heavier infection with malnutrition, and this model may be useful in exploring innovative therapeutic solutions for this challenging infectious disease.

Effect of probiotic bacteria on microbial host defense, growth, and immune function in human immunodeficiency virus type-1 infection

The hypothesis that probiotic administration protects the gut surface and could delay progression of Human Immunodeficiency Virus type1 (HIV-1) infection to the Acquired Immunodeficiency Syndrome (AIDS) was proposed in 1995. Over the last five years, new studies have clarified the significance of HIV-1 infection of the gut associated lymphoid tissue (GALT) for subsequent alterations in the microflora and breakdown of the gut mucosal barrier leading to pathogenesis and development of AIDS. Current studies show that loss of gut CD4+ Th17 cells, which differentiate in response to normal microflora, occurs early in HIV-1 disease. Microbial translocation and suppression of the T regulatory (Treg) cell response is associated with chronic immune activation and inflammation. Combinations of probiotic bacteria which upregulate Treg activation have shown promise in suppressing pro inflammatory immune response in models of autoimmunity including inflammatory bowel disease and provide a rationale for use of probiotics in HIV-1/AIDS. Disturbance of the microbiota early in HIV-1 infection leads to greater dominance of potential pathogens, reducing levels of bifidobacteria and lactobacillus species and increasing mucosal inflammation. The interaction of chronic or recurrent infections, and immune activation contributes to nutritional deficiencies that have lasting consequences especially in the HIV-1 infected child. While effective anti-retroviral therapy (ART) has enhanced survival, wasting is still an independent predictor of survival and a major presenting symptom. Congenital exposure to HIV-1 is a risk factor for growth delay in both infected and non-infected infants. Nutritional intervention after 6 months of age appears to be largely ineffective. A meta analysis of randomized, controlled clinical trials of infant formulae supplemented with Bifidobacterium lactis showed that weight gain was significantly greater in infants who received B. lactis compared to formula alone. Pilot studies have shown that probiotic bacteria given as a supplement have improved growth and protected against loss of CD4+ T cells. The recognition that normal bacterial flora prime neonatal immune response and that abnormal flora have a profound impact on metabolism has generated insight into potential mechanisms of gut dysfunction in many settings including HIV-1 infection. As discussed here, current and emerging studies support the concept that probiotic bacteria can provide specific benefit in HIV-1 infection. Probiotic bacteria have proven active against bacterial vaginosis in HIV-1 positive women and have enhanced growth in infants with congenital HIV-1 infection. Probiotic bacteria may stabilize CD4+ T cell numbers in HIV-1 infected children and are likely to have protective effects against inflammation and chronic immune activation of the gastrointestinal immune system.

Alanyl-glutamine promotes intestinal epithelial cell homeostasis in vitro and in a murine model of weanling undernutrition

Alanyl-glutamine (Ala-Gln) has recently been shown to enhance catch-up growth and gut integrity in undernourished children from Northeast Brazil. We hypothesized that the intestinal epithelial effects of Ala-Gln in malnourished weanling mice and mouse small intestinal epithelial (MSIE) cells would include modulation of barrier function, proliferation, and apoptosis. Dams of 10-day-old suckling C57BL/6 pups were randomized to a standard diet or an isocaloric Northeast Brazil "regional basic diet," moderately deficient in protein, fat, and minerals. Upon weaning to their dam's diet on day of life 21, pups were randomized to Ala-Gln solution or water. At 6 wk of age, mice were killed, and jejunal tissue was collected for morphology, immunohistochemistry, and Ussing chamber analysis of transmucosal resistance and permeability. Proliferation of MSIE cells in the presence or absence of Ala-Gln was measured by MTS and bromodeoxyuridine assays. MSIE apoptosis was assessed by annexin and 7-amino-actinomycin D staining. Pups of regional basic diet-fed dams exhibited failure to thrive. Jejunal specimens from undernourished weanlings showed decreased villous height and crypt depth, decreased transmucosal resistance, increased permeability to FITC-dextran, increased claudin-3 expression, and decreased epithelial proliferation and increased epithelial apoptosis (as measured by bromodeoxyuridine and cleaved caspase-3 staining, respectively). Undernourished weanlings supplemented with Ala-Gln showed improvements in weight velocity, villous height, crypt depth, transmucosal resistance, and epithelial proliferation/apoptosis compared with unsupplemented controls. Similarly, Ala-Gln increased proliferation and reduced apoptosis in MSIE cells. In summary, Ala-Gln promotes intestinal epithelial homeostasis in a mouse model of malnutrition-associated enteropathy, mimicking key features of the human disease.

AIDS diarrhea and antiretroviral drug concentrations: a matched-pair cohort study in Port au Prince, Haiti

Diarrhea in patients with acquired immunodeficiency syndrome (AIDS) may cause malabsorption of medications and failure of antiretroviral therapy (ART). We prospectively evaluated human immunodeficiency virus-1 (HIV-1)-infected patients with and without chronic diarrhea initiating ART in Haiti. We report mean plasma antiretroviral concentrations at 2 and 4 weeks. We measured plasma HIV-1 RNA levels at four points. Fifty-two HIV-1-infected patients (26 matched pairs) were enrolled. No differences in antiretroviral concentrations were detected. At week 24, 18/25 (72%) cases and 16/24 (68%) controls had undetectable plasma HIV-1 RNA levels (P = 0.69). Patients with plasma HIV-1 RNA levels > 50 copies/mL at week 24 had lower early efavirenz concentrations than patients with undetectable HIV-1 RNA (2,621 ng/mL versus 5,278 ng/mL; P = 0.02). Diarrhea at ART initiation does not influence plasma concentrations of the medications evaluated. Virologic outcome at Week 24 does correlate with efavirenz concentrations early in therapy but not with the presence of chronic diarrhea.

Drinking water quality, feeding practices, and diarrhea among children under 2 years of HIV-positive mothers in peri-urban Zambia

In low-income settings, human immunodeficiency virus (HIV)-positive mothers must choose between breastfeeding their infants and risking transmission of HIV or replacement feeding their infants and risking diarrheal disease from contaminated water. We conducted a cross-sectional study of children < 2 years of age of 254 HIV-positive mothers in peri-urban Zambia to assess their exposure to waterborne fecal contamination. Fecal indicators were found in 70% of household drinking water samples. In a multivariable analysis, factors associated with diarrhea prevalence in children < 2 years were mother having diarrhea (adjusted odds ratio [aOR] = 5.18, 95% confidence interval [CI] = 1.65-16.28), child given water in the past 2 days (aOR = 4.08, 95% CI = 1.07-15.52), child never being breastfed (aOR = 2.67, 95% CI = 1.06-6.72), and rainy (versus dry) season (aOR = 4.60, 95% CI = 1.29-16.42). Children born to HIV-positive mothers were exposed to contaminated water through direct intake of drinking water, indicating the need for interventions to ensure microbiological water quality.

Hepatitis C and B prevalence in Spanish prisons

Purpose The Prevalhep study seeks to determine the prevalence of factors associated with the hepatitis C (HCV) and B (HBV) virus in Spanish prisoners. Methods This was an observational, cross-sectional study which randomly selected 18 Spanish prisons to participate, with 21 prisoners per centre. Results There were 378 prisoners selected, 370 of whom had serological HCV and 342 had HBV data. The HCV population was predominantly male (91.6%), middle age (66.7% ≤ 40 years of age), of Spanish origin (60.5%), with a history of injection drug use (IDU; 23.2%), in prison <5 years (71.2%) and having entered prison after 2006 (51.9%). The prevalence of HCV was 22.7% (n = 84; 95% CI, 18.3-27.1) and HBV was 2.6% (n = 9; 95% CI, 0.2-4.9%). Of the patients with HCV, 40.5% were co-infected with HIV, 0.3% co-infected with HBV, and 1.5% with triple virus co-infection (HBV + HCV + HIV). The three markers of HB had been measured in 99 inmates: 32.1% had post-vaccination immunity (antiHBS+) and 30.4% contact status with HBV (HBcAb + and/or HBsAg+), while 37.5% were susceptible to HB. Conclusions The prevalence of HBV and HCV has decreased in the Spanish prison population, probably as a result of decrease in IDU transmission, and an increase in immigrant prisoner population that does not have this risk behaviour.

Treatment of cryptosporidiosis: do we know what we think we know?

PURPOSE OF REVIEW

The management of cryptosporidiosis is fraught with controversies. New research on diagnostics and medications has reached the field in recent years. Therefore, familiarity with key features of current management tools is important. We discuss diagnostic and therapeutic aspects of cryptosporidiosis focusing on evidence behind the medications available to date.

RECENT FINDINGS

Molecular methods provide a clearer understanding of cryptosporidiosis epidemiology. The major determinants of severity still are host immune status and parasite species. Children and immunosuppressed individuals, especially with HIV/AIDS, are disproportionately affected. Nitazoxanide is an important advance in treatment of HIV negative patients. However, recent research confirms the limited effectiveness of antiparasitic drugs to treat cryptosporidiosis in AIDS. Questions remain about using partially active drugs paromomycin and nitazoxanide for treatment. Potent antiretroviral combinations modify disease epidemiology and are key components of therapy in AIDS. However, it is unclear whether this is due solely to immune reconstitution or due in part to antiparasitic effects of HIV protease inhibitors. Newer candidate drugs are in development.

SUMMARY

There is better understanding of the epidemiology of cryptosporidiosis and promising new diagnostic methods. There are significant challenges in terms of control and treatment of cryptosporidiosis among the groups at risk.

Evaluation of HIV protease and nucleoside reverse transcriptase inhibitors on proliferation, necrosis, apoptosis in intestinal epithelial cells and electrolyte and water transport and epithelial barrier function in mice

Background

Protease inhibitors (PI's) and reverse transcriptase drugs are important components of highly active antiretroviral therapy (HAART) for treating human acquired immunodeficiency syndrome (AIDS). Long-term clinical therapeutic efficacy and treatment compliance of these agents have been limited by undesirable side-effects, such as diarrhea. This study aims to investigate the effects of selected antiretroviral agents on intestinal histopathology and function in vivo and on cell proliferation and death in vitro.

Methods

Selected antiretroviral drugs were given orally over 7 days, to Swiss mice, as follows: 100 mg/kg of nelfinavir (NFV), indinavir (IDV), didanosine (DDI) or 50 mg/kg of zidovudine (AZT). Intestinal permeability measured by lactulose and mannitol assays; net water and electrolyte transport, in perfused intestinal segments; and small intestinal morphology and cell apoptosis were assessed in treated and control mice. In vitro cell proliferation was evaluated using the WST-1 reagent and apoptosis and necrosis by flow cytometry analysis.

Results

NFV, IDV, AZT and DDI caused significant reductions in duodenal and in jejunal villus length (p < 0.05). IDV and AZT increased crypt depth in the duodenum and AZT increased crypt depth in the jejunum. NFV, AZT and DDI significantly decreased ileal crypt depth. All selected antiretroviral drugs significantly increased net water secretion and electrolyte secretion, except for DDI, which did not alter water or chloride secretion. Additionally, only NFV significantly increased mannitol and lactulose absorption. NFV and IDV caused a significant reduction in cell proliferation in vitro at both 24 h and 48 h. DDI and AZT did not alter cell proliferation. There was a significant increase in apoptosis rates in IEC-6 cells after 24 h with 70 ug/mL of NFV (control: 4.7% vs NFV: 22%) while IDV, AZT and DDI did not show any significant changes in apoptosis compared to the control group. In jejunal sections, IDV and NFV significantly increased the number of TUNEL positive cells.

Conclusion

The PI's, NFV and IDV, increased cell apoptosis in vivo, water and electrolyte secretion and intestinal permeability and decreased villus length and cell proliferation. NFV was the only drug tested that increased cell apoptosis in vitro. The nucleoside reverse transcriptase inhibitors, AZT and DDI, did not affect cell apoptosis or proliferation. These findings may partly explain the intestinal side-effects associated with PI's.

Cryptosporidium infection causes undernutrition and, conversely, weanling undernutrition intensifies infection

Cryptosporidium parvum is a leading pathogen in children in developing countries. To investigate whether early postnatal malnutrition leads to heavier C. parvum infections, we assessed intestinal adaptation and parasite load in suckling mice during the first 2 wk of life, analogous to the first postnatal yr in humans. Undernutrition was induced by daily C57BL6J pup separation from lactating dams. Half of the pups were separated daily, for 4 hr on day 4, 8 hr on day 5, and for 12 hr from day 6 until day 14. On day 6, each pup received an oral inoculum of 10(5) to 10(7) parasites in 10-25 microl of PBS. Littermate controls received PBS alone. Stools were assessed from days 8, 11, and 14 for oocyst counts. Mice were killed on day 14, 8 days postinoculation, at the peak of the infection. Ileal and colon segments were obtained for histology, real-time and reverse transcriptase PCR, and immunoassays. Villus and crypt lengths and cross-sectional areas were also measured. Undernourished and nourished mice infected with excysted 10(6) or 10(7) oocysts exhibited the poorest growth outcomes compared with their uninfected controls. Nourished 10(6)-infected mice had comparable weight decrements to uninfected undernourished mice. Body weight and villi were additively affected by malnutrition and cryptosporidiosis. Hyperplastic crypts and heavier inflammatory responses were found in the ilea of infected malnourished mice. Undernourished infected mice exhibited greater oocyst shedding, TNF-alpha and IFN-gamma intestinal levels, and mRNA expression compared to nourished mice infected with either 10(5) or 10(6) oocysts. Taken together, these findings show that Cryptosporidium infection can cause undernutrition and, conversely, that weanling undernutrition intensifies infection and mucosal damage.

Malnutrition as an enteric infectious disease with long-term effects on child development

Malnutrition is a major contributor to mortality and is increasingly recognized as a cause of potentially lifelong functional disability. Yet, a rate-limiting step in achieving normal nutrition may be impaired absorptive function due to multiple repeated enteric infections. This is especially problematic in children whose diets are marginal. In malnourished individuals, the infections are even more devastating. This review documents the evidence that intestinal infections lead to malnutrition and that malnutrition worsens intestinal infections. The clinical data presented here derive largely from long-term cohort studies that are supported by controlled animal studies. Also reviewed are the mechanisms by which enteric infections lead to undernutrition and by which malnutrition worsens enteric infections, with implications for potential novel interventions. Further intervention studies are needed to document the relevance of these mechanisms and, most importantly, to interrupt the vicious diarrhea-malnutrition cycle so children may develop their full potential.

Enteric infections, diarrhea, and their impact on function and development

Enteric infections, with or without overt diarrhea, have profound effects on intestinal absorption, nutrition, and childhood development as well as on global mortality. Oral rehydration therapy has reduced the number of deaths from dehydration caused by infection with an enteric pathogen, but it has not changed the morbidity caused by such infections. This Review focuses on the interactions between enteric pathogens and human genetic determinants that alter intestinal function and inflammation and profoundly impair human health and development. We also discuss specific implications for novel approaches to interventions that are now opened by our rapidly growing molecular understanding.

Wasting and intestinal barrier function in children taking alanyl-glutamine-supplemented enteral formula

OBJECTIVE

We examined the effect of a diet supplemented with alanyl-glutamine (AG) or placebo glycine (G) on intestinal barrier function and growth in children in northeastern Brazil.

PATIENTS AND METHODS

One hundred seven children ages 7.9 to 82.2 months with a weight-for-age (WAZ), height-for-age (HAZ), or weight-for-height (WHZ) z-score less than -1 were studied. From July 2003 to November 2004, 51 study patients received AG (24 g/d) and 56 received G (25 g/d; isonitrogenic concentration) control for 10 days. Lactulose/mannitol excretion ratio was used as a measure of intestinal permeability and was performed on days 1 and 10 of nutritional supplementation. Weight and height were measured on days 1, 10, 30, and 120 of the protocol.

RESULTS

The patients were similar on admission with regard to age, sex, birth weight, nutritional status, lactulose/mannitol ratio, and serum concentrations of glutamine and arginine. The percentage of lactulose urinary excretion significantly improved (decreased) in children receiving AG for 10 days but not in those receiving glycine controls. AG significantly increased cumulative change over 120 days in WHZ and WAZ scores but not HAZ scores after adjustment for age and season in comparison with the placebo glycine group.

CONCLUSIONS

Children tolerated AG-supplemented enteral formula well, and it significantly improved cumulative WHZ and WAZ over 120 days in comparison with children in the placebo glycine group. The data also suggested a beneficial effect of AG in the barrier function paracellular pathway, albeit with reduced mannitol excretion. Thus, although the effect of AG on reduced mannitol concentration requires clarification, AG appears to improve nutrition and barrier function.

Micronutrients in HIV-positive persons receiving highly active antiretroviral therapy

In HIV-infected persons, low serum concentrations of vitamins and minerals, termed micronutrients, are associated with an increased risk of HIV disease progression and mortality. Micronutrient supplements can delay HIV disease progression and reduce mortality in HIV-positive persons not receiving highly active antiretroviral therapy (HAART). With the transition to more universal access to HAART, a better understanding of micronutrient deficiencies and the role of micronutrient supplements in HIV-positive persons receiving HAART has become a priority. The provision of simple, inexpensive micronutrient supplements as an adjunct to HAART may have several cellular and clinical benefits, such as a reduction in mitochondrial toxicity and oxidative stress and an improvement in immune reconstitution. We reviewed observational and trial evidence on micronutrients in HIV-positive persons receiving HAART to summarize the current literature and suggest future research priorities. A small number of observational studies have suggested that some, but not all, micronutrients may become replete after HAART initiation, and few intervention studies have found that certain micronutrients may be a beneficial adjunct to HAART. However, most of these studies had some major limitations, including a small sample size, a short duration of follow-up, a lack of adjustment for inflammatory markers, and an inadequate assessment of HIV-related outcomes. Therefore, few data are available to determine whether HAART ameliorates micronutrient deficiencies or to recommend or refute the benefit of providing micronutrient supplements to HIV-positive persons receiving HAART. Because micronutrient supplementation may cause harm, randomized placebo-controlled trials are needed. Future research should determine whether HAART initiation restores micronutrient concentrations, independent of inflammatory markers, and whether micronutrient supplements affect HIV-related outcomes in HIV-positive persons receiving HAART.

Global impact of diarrheal diseases that are sampled by travelers: the rest of the hippopotamus

Travelers who experience diarrhea (i.e., "turista") are exposed to the same pathogens and illnesses that pose some of the greatest threats to life and development among malnourished children in developing areas around the world, where inadequate water and poor sanitation remain. This article focuses on new findings about the impact, diagnosis, and control of these illnesses and the genetic predispositions of persons who acquire them. Despite the reductions in mortality due to dehydrating diarrhea, the morbidity associated with diarrheal illnesses continues unabated. Furthermore, we increasingly recognize the lasting detrimental effects of enteric infections that occur during early childhood on later physical and cognitive development and, in patients with acquired immunodeficiency syndrome, on the absorption of antiretroviral drugs. Genetic predispositions to inflammation and potential protection associated with such alleles as ApoE4, which are not suspected of being involved in diarrhea, remind us of how much we have to learn about the effect and interactions of enteric tropical infectious diseases with regard to our host genome. New diagnostic methods hold promise for improved recognition and, hopefully, control of enteric infections worldwide.

An updated review on Cryptosporidium and Giardia

Cryptosporidium and Giardia are two of the most commonly occurring enteric protozoans. They are responsible for diarrheal diseases that may lead to nutritional deficiencies and significant morbidity and mortality, especially among children in developing countries and patients who have immune defects. Both are difficult to diagnose with microscopic techniques. This article provides an updated review of the epidemiology, pathogenesis, clinical manifestations, and treatment of Cryptosporidium and Giardia.

A Bayesian approach to acute infectious diarrhea in adults

Acute infectious diarrhea is a yearly occurrence for most Americans, and is associated with 1 million hospitalizations and about 6000 deaths in the United States annually. Up to 80% of acute infectious diarrhea is caused by noroviruses, which produce a clinically mild illness with a predictable short course and good outcome that make laboratory testing and antimicrobial treatment unnecessary. Most diarrhea-causing bacteria and protozoa can cause a clinical illness "like norovirus"; when they do so in healthy adults neither specialized testing nor antimicrobials is required. The presence or absence of epidemiologic evidence (such as travel, hospitalization, antibiotic use, other exposures)and clinical evidence (such as diarrhea frequency and duration, severity of abdominal pain and fever, character of stool, presence of chronic illness or immune deficiency) can change the probability of "not norovirus" from as low as 8% to as high as 100%. Such probabilities guide the use of laboratory testing and antimicrobial therapy in patients who have acute infectious diarrhea.

Diarrhea in patients with AIDS

Diarrhea in patients with AIDS is a worldwide problem that can have a devastating impact on quality of life for the patient. Chronic diarrhea, usually defined as at least 4 weeks' duration, is more common in patients with low CD4-positive T-lymphocyte counts, signaling advanced immunosuppression. Some organisms, such as Microsporidia, usually cause diarrhea only in the immunosuppressed; others, such as Cryptosporidium, Salmonella, Shigella, and Campylobacter, which are capable of causing diarrhea in the immunocompetent population, produce more severe or prolonged infections in people living with AIDS. Familiarity with the most common pathogens in the clinician's region will help with diagnosis and treatment. Because treatment options vary widely depending upon the infectious agent, thorough microbiologic evaluation is warranted. A stepped diagnostic approach of stool cultures and specialized microscopy and stains for protozoa, followed by sigmoidoscopy or colonoscopy and duodenoscopy with biopsies for histopathological examination is recommended in all patients with persistent, disabling diarrhea who have a CD4 count of less than 200/mm3, and should be considered for those with higher counts on an individual basis. Treatment, tailored to the specific pathogen, may need to be prolonged in the most severely immunocompromised patients to prevent relapse or recrudescence. For patients taking antiretroviral therapy (especially protease inhibitors) in whom no infectious agent can be found, diarrhea may be due to the medications. Nonspecific antidiarrheal agents should be tried until one that suits the patient is found. The most essential component of any therapeutic strategy for a patient with AIDS-associated diarrhea is restoration of the underlying immunologic defect using highly active antiretroviral therapy.

Caspase and bid involvement in Clostridium difficile toxin A-induced apoptosis and modulation of toxin A effects by glutamine and alanyl-glutamine in vivo and in vitro

Clostridium difficile is the leading cause of nosocomial bacterial diarrhea. Glutamine and its stable and highly soluble derivative alanyl-glutamine, have been beneficial in models of intestinal injury. In this study, we extend our work on the mechanisms of Clostridium difficile toxin A (TxA)-induced apoptosis in human intestinal epithelial T84 cells and evaluate the effects of glutamine and alanyl-glutamine on TxA-induced apoptosis in vitro and disruption of ileal mucosa in vivo. T84 cells were incubated with TxA (100 ng/ml) in medium with or without glutamine or alanyl-glutamine (3 to 100 mM). Apoptosis was evaluated by DNA fragmentation in vitro and the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end-labeling method in vivo. Caspase and Bid involvement were investigated by Western blotting. Ligated rabbit ileal loops were used for the evaluation of intestinal secretion, mucosal disruption, and apoptosis. TxA induced caspases 6, 8, and 9 prior to caspase 3 activation in T84 cells and induced Bid cleavage by a caspase-independent mechanism. Glutamine or alanyl-glutamine significantly reduced TxA-induced apoptosis of T84 cells by 47% and inhibited activation of caspase 8. Both glutamine and alanyl-glutamine reduced TxA-induced ileal mucosal disruption and secretion. Altogether, we further delineated the apoptosis-signaling cascade induced by TxA in T84 cells and demonstrated the protective effects of glutamine and alanyl-glutamine. Glutamine and alanyl-glutamine inhibited the apoptosis of T84 cells by preventing caspase 8 activation and reduced TxA-induced intestinal secretion and disruption.

Double-blind pilot study of mesalamine vs. placebo for treatment of chronic diarrhea and nonspecific colitis in immunocompetent HIV patients

Chronic diarrhea and colitis are common in patients positive for human immunodeficiency virus (HIV) under highly active antiretroviral treatment (HAART). This prospective double-blind study explores the effect of mesalamine vs. placebo in HIV-positive patients. Thirteen HIV-infected patients with noninfectious chronic diarrhea and > 250 CD4+ cells/mm(3) were randomized to mesalamine (2.4 g/day; n = 9) or placebo (n = 4) for 6 weeks. Colonoscopy was performed at baseline and week 6, and biopsies were obtained to calculate the Biopsy Activity Index (BAI). Diarrhea was assessed at baseline and end of treatment using the Disease Activity Index (DAI). Patients and clinicians completed Patient Global Improvement index (PGI) and Clinical Global Improvement index (CGI) at weeks 2 and 6. Comparisons at week 6 were statistically significant between mesalamine and placebo groups for BAI (P = 0.03), DAI (P = 0.007), PGI (P = 0.008), and CGI (P = 0.008). Furthermore, major improvements were documented in the mesalamine group at week 6 compared to baseline for all variables, whereas the placebo group did not have any. Mesalamine was effective for treatment of chronic diarrhea and moderate nonspecific colitis in HIV patients.

Gastrointestinal infections in immunocompromised hosts

PURPOSE OF REVIEW

Gastrointestinal infections in the immunocompromised host continue to have significant morbidity and mortality throughout the world. They all have similar exposures to viruses, bacteria and parasites and respond to these infections in a similar way. This review will summarize the latest reports on the epidemiology, diagnosis and treatment of known and emerging infections over the last 12 months.

RECENT FINDINGS

Highly active antiretroviral therapy has reduced esophageal opportunistic infections in HIV patients compared to patients who are not taking this therapy. Esophageal candidiasis responds to escalating doses of micafungin as effectively as fluconazole. HIV-infected patients with untreated Mycobacterium avium-complex diarrhea are associated with a wasting syndrome that disrupts the somatostatin axis. Polymerase chain reaction testing has improved diagnosis of microsporidial infections. Cytomegalovirus polymerase chain reaction of tissue may improve the diagnosis of cytomegalovirus disease of the gastrointestinal tract in organ-transplant recipients. The treatment of hypogammaglobulinemia in transplant recipients with recurrent cytomegalovirus gastrointestinal disease may resolve their symptoms. Community viruses are an emerging threat to transplant recipients and may affect drug levels. Lastly, anti-tumor necrosis factor alpha therapy in the treatment of inflammatory conditions may cause Listeria monocytogenes to disseminate.

SUMMARY

Immunocompromised hosts remain at risk for severe gastrointestinal and even disseminated infections. Management includes an early rapid diagnosis with rapid restoration of the immune system and appropriate anti-infective therapy. With the immunocompromised population rapidly increasing, prevention of these infections remains the greatest challenge.

Therapeutic Drug Monitoring: Role for a Pharmacist in Multidisciplinary Antiretroviral Management

The current treatment guidelines for HIV pharmacotherapy recommend combinations of antiretrovirals (ARVs) to achieve optimal suppression of HIV replication. However, the initiation and long-term management of ARV therapy in a patient is often complicated by variable medication adherence, complex medication use with multiple drug interactions, the occurrence of drug toxicity, and drug therapy for comorbid conditions that require additional patient education and laboratory monitoring. For these reasons, the inclusion of a well-trained pharmacist in multidisciplinary health system management strategies has been increasing. Furthermore, the use of fixed-dose ARVs is accompanied by considerable interpatient variation in pharmacokinetics yielding a range of drug exposures from any given ARV dose. One approach to overcoming this variable drug exposure is to use plasma concentration monitoring (eg, therapeutic drug monitoring [TDM]) as a clinical tool to adjust doses to achieve targeted concentration ranges, often in conjunction with HIV resistance tests. While data in support of TDM are emerging, the development of programs that include an HIV pharmaceutical care specialist and an adherence program with an integrated clinical pharmacology resource that can provide reliable TDM assays has been reported and provides the rationale for including pharmacists in the implementation of ARV TDM programs.

Alanyl-glutamine hastens morphologic recovery from 5-fluorouracil-induced mucositis in mice

OBJECTIVE

In this study, we postulated the beneficial role of oral alanyl-glutamine, a more stable glutamine derivative to decrease 5-fluorouracil (5-FU)-induced mucositis in mice.

METHODS

We measured different morphologic parameters to assess structural changes over time in the small bowel, including crypt depth, villus height, villus area, mitotic and apoptotic indices at the crypt level using terminal deoxyuridine triphosphate nick end labeling, and hematoxylin-eosin staining of ileal tissue. In addition, we analyzed the effect of different alanyl-glutamine concentrations on animal weight curves after 5-FU treatment.

RESULTS

Neither glutamine nor alanyl- glutamine prevented the 5-FU intestinal structural damage or apoptosis in crypt enterocytes at 24 h after 5-FU challenge. However, we found that alanyl-glutamine, but not glutamine, speeds intestinal recovery when compared with 5-FU-treated controls (P < 0.05), predominantly by enhancing mitotic activity and crypt length.

CONCLUSION

Our findings provide important data to support clinical studies of oral alanyl-glutamine in 5-FU-induced mucositis.