Intelligent Biological Networks: Improving Anti-Microbial Resistance Resilience through Nutritional Interventions to Understand Protozoal Gut Infections

Enteric protozoan pathogenic infections significantly contribute to the global burden of gastrointestinal illnesses. Their occurrence is considerable within remote and indigenous communities and regions due to reduced access to clean water and adequate sanitation. The robustness of these pathogens leads to a requirement of harsh treatment methods, such as medicinal drugs or antibiotics. However, in addition to protozoal infection itself, these treatments impact the gut microbiome and create dysbiosis. This often leads to opportunistic pathogen invasion, anti-microbial resistance, or functional gastrointestinal disorders, such as irritable bowel syndrome. Moreover, these impacts do not remain confined to the gut and are reflected across the gut-brain, gut-liver, and gut-lung axes, among others. Therefore, apart from medicinal treatment, nutritional supplementation is also a key aspect of providing recovery from this dysbiosis. Future proteins, prebiotics, probiotics, synbiotics, and food formulations offer a good solution to remedy this dysbiosis. Furthermore, nutritional supplementation also helps to build resilience against opportunistic pathogens and potential future infections and disorders that may arise due to the dysbiosis. Systems biology techniques have shown to be highly effective tools to understand the biochemistry of these processes. Systems biology techniques characterize the fundamental host-pathogen interaction biochemical pathways at various infection and recovery stages. This same mechanism also allows the impact of the abovementioned treatment methods of gut microbiome remediation to be tracked. This manuscript discusses system biology approaches, analytical techniques, and interaction and association networks, to understand (1) infection mechanisms and current global status; (2) cross-organ impacts of dysbiosis, particularly within the gut-liver and gut-lung axes; and (3) nutritional interventions. This study highlights the impact of anti-microbial resistance and multi-drug resistance from the perspective of protozoal infections. It also highlights the role of nutritional interventions to add resilience against the chronic problems caused by these phenomena.

Soy and Gastrointestinal Health: A Review

Soybean is the most economically important legume globally, providing a major source of plant protein for millions of people; it offers a high-quality, cost-competitive and versatile base-protein ingredient for plant-based meat alternatives. The health benefits of soybean and its constituents have largely been attributed to the actions of phytoestrogens, which are present at high levels. Additionally, consumption of soy-based foods may also modulate gastrointestinal (GI) health, in particular colorectal cancer risk, via effects on the composition and metabolic activity of the GI microbiome. The aim of this narrative review was to critically evaluate the emerging evidence from clinical trials, observational studies and animal trials relating to the effects of consuming soybeans, soy-based products and the key constituents of soybeans (isoflavones, soy proteins and oligosaccharides) on measures of GI health. Our review suggests that there are consistent favourable changes in measures of GI health for some soy foods, such as fermented rather than unfermented soy milk, and for those individuals with a microbiome that can metabolise equol. However, as consumption of foods containing soy protein isolates and textured soy proteins increases, further clinical evidence is needed to understand whether these foods elicit similar or additional functional effects on GI health.

Pediatric Intussusception Following COVID-19 Infection: A Rare Presentation

Pediatric intussusception has been reported to be associated with coronavirus disease 2019 (COVID-19) infection in the literature since the start of the pandemic in the past two years. Although this occurrence is exceptionally rare, rapid diagnosis based on recognition of gastrointestinal manifestations, clinical examination, and ultrasound confirmation can expedite appropriate care and prevent delayed complications. Intussusception is the most common cause of intestinal obstruction and acute abdomen in pediatric patients. Without prompt identification, the disease process can lead to necrosis, bowel perforation, shock, and, subsequently, multiorgan failure. Intussusception has previously been associated with viral upper respiratory infections, which can cause mesenteric lymphadenopathy as a lead point to allow the bowel to telescope upon itself. The mechanism of how COVID-19 can contribute to intussusception without respiratory symptoms remains unknown. Here, we present a case of pediatric intussusception associated with COVID-19.

Fear-Related Reasons for Avoiding Sexual Intercourse in Early Pregnancy: A Cross-Sectional Study

Introduction

Several studies have reported women's worry that sexual intercourse may harm the course of pregnancy. This worry might lead to avoidance of sexual intercourse during pregnancy.

Aim

To assess if fears about harming the pregnancy are associated with avoidance of sexual intercourse during pregnancy.

Methods

A cross-sectional study was conducted on 250 Vietnamese pregnant women in the first or second trimester who visited our hospital for antenatal care. We explored 5 types of fears including miscarriage/preterm labor, premature rupture of membranes, bleeding, infection, and injury to the fetus. Fears were measured by modified questions from the Reasons For Not Engaging in Sexual Activity During Pregnancy questionnaire. Using the total fear score, pregnant women were categorized into having low, moderate, and high fear.

Main Outcome Measure

Not having sexual intercourse during the past 4 weeks.

Results

72 (28.8%) pregnant women had no sexual intercourse for the past 4 weeks. All types of fear were considered important among pregnant women; the more important fears were infection and injury to the fetus. In multivariable regression analysis, the prevalence of not having sexual intercourse was higher in both women who had moderate (adjusted prevalence ratio = 2.84, 95% CI 1.42–5.67) and high fear (adjusted prevalence ratio = 4.39, 95% CI 2.28–8.44).

Conclusion

Avoidance of sexual intercourse was common among Vietnamese pregnant women and was associated with the fears about harming the pregnancy. This can be a target in the health education programs for pregnancy couples.

Thanh C. Phan, Long B. Hoang, Thanh K. Tran, et al. Fear-Related Reasons for Avoiding Sexual Intercourse in Early Pregnancy: A Cross-Sectional Study. Sex Med 2021;9:100430.

Associations between diet, the gut microbiome and short chain fatty acids in youth with islet autoimmunity and type 1 diabetes

AIM

We aimed to characterize associations between diet and the gut microbiome and short chain fatty acid (SCFA) products in youth with islet autoimmunity or type 1 diabetes (IA/T1D) in comparison with controls.

RESEARCH DESIGN AND METHODS

Eighty participants (25 diagnosed with T1D, 17 with confirmed IA, 38 sibling or unrelated controls) from the Australian T1D Gut Study cohort were studied (median [IQR] age 11.7 [8.9, 14.0] years, 43% female). A Food Frequency Questionnaire characterized daily macronutrient intake over the preceding 6 months. Plasma and fecal SCFA were measured by gas chromatography; gut microbiome composition and diversity by 16S rRNA gene sequencing.

RESULTS

A 10 g increase in daily carbohydrate intake associated with higher plasma acetate in IA/T1D (adjusted estimate +5.2 (95% CI 1.1, 9.2) μmol/L p = 0.01) and controls (adjusted estimate +4.1 [95% CI 1.7, 8.5] μmol/L p = 0.04). A 5 g increase in total fat intake associated with lower plasma acetate in IA/T1D and controls. A 5% increase in noncore (junk) food intake associated with reduced richness (adjusted estimate -4.09 [95%CI -7.83, -0.35] p = .03) and evenness (-1.25 [95% CI -2.00, -0.49] p < 0.01) of the gut microbiome in IA/T1D. Fiber intake associated with community structure of the microbiome in IA/T1D.

CONCLUSIONS

Modest increments in carbohydrate and fat intake associated with plasma acetate in all youth. Increased junk food intake associated with reduced diversity of the gut microbiome in IA/T1D alone. These associations with the gut microbiome in IA/T1D support future efforts to promote SCFA by using dietary interventions.

Almond consumption affects fecal microbiota composition, stool pH, and stool moisture in overweight and obese adults with elevated fasting blood glucose: A randomized controlled trial

Regular almond consumption has been shown to improve body weight management, lipid profile and blood glucose control. We hypothesized that almond consumption would alter fecal microbiota composition, including increased abundance and activity of potentially beneficial bacterial taxa in adults who are overweight and obese with elevated fasting blood glucose. A total of 69 adults who were overweight or obese with an elevated plasma glucose (age: 60.8 ± 7.4, BMI ≥27 kg/m², fasting plasma glucose ≥5.6 to <7.0 mmol/L) were randomized to daily consumption of either 2 servings of almonds (AS:56 g/day) or an isocaloric, high carbohydrate biscuit snack for 8 weeks. AS but not biscuit snack experienced significant changes in microbiota composition (P= .011) and increases in bacterial richness, evenness, and diversity (P< .01). Increases in both the relative and absolute abundance of operational taxonomic units in the Ruminococcaceae family, including Ruminiclostridium (false discovery rate P = .002), Ruminococcaceae NK4A214 (P = .002) and Ruminococcaceae UCG-003 (P = .002) were the principal drivers of microbiota-level changes. No changes in fecal short chain fatty acid levels, or in the carriage of the gene encoding butyryl-CoA:acetate CoA-transferase (an enzyme involved in butyrate synthesis) occurred. Almond consumption was not associated with reduced gut permeability, but fecal pH (P= .0006) and moisture content (P = .027) decreased significantly in AS when compared to BS. Regular almond consumption increased the abundance of potentially beneficial ruminococci in the fecal microbiota in individuals with elevated blood glucose. However, fecal short-chain fatty acid levels remained unaltered and the capacity for such microbiological effects to precipitate host benefit is not known.

Organic contaminants in human breast milk identified by non-targeted analysis

Understanding the health implications of human exposure to mixtures of chemical contaminants is aided by analytical methods that can screen for a broad range of both expected and unexpected compounds. We performed a proof-of-concept analysis combining human breast milk, a biomonitoring matrix for determining contaminant exposure to mothers and infants, with a non-targeted method based on comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC/TOF-MS). A total of 172 presumably anthropogenic halogenated compounds and non-halogenated cyclic and aromatic compounds were tentatively identified in breast milk from San Diego, California through mass spectral database searches. Forty of the compounds were prioritized for confirmation based on halogenation or 100% frequency of detection, and the identities of 30 were verified using authentic standards. Thirty-four (85%) of the prioritized contaminants are not typically monitored in breast milk surveys, and 31 (77%) are regulated in at least one market worldwide, indicating breast milk may be a useful biomonitoring matrix for non-targeted analysis and the assessment of human exposure to future emerging or undiscovered contaminants.

Gut microbiome dysbiosis and increased intestinal permeability in children with islet autoimmunity and type 1 diabetes: A prospective cohort study

AIMS/HYPOTHESIS

To investigate the longitudinal relationship between the gut microbiome, circulating short chain fatty acids (SCFAs) and intestinal permeability in children with islet autoimmunity or type 1 diabetes and controls.

METHODS

We analyzed the gut bacterial microbiome, plasma SCFAs, small intestinal permeability and dietary intake in 47 children with islet autoimmunity or recent-onset type 1 diabetes and in 41 unrelated or sibling controls over a median (range) of 13 (2-34) months follow-up.

RESULTS

Children with multiple islet autoantibodies (≥2 IA) or type 1 diabetes had gut microbiome dysbiosis. Anti-inflammatory Prevotella and Butyricimonas genera were less abundant and these changes were not explained by differences in diet. Small intestinal permeability measured by blood lactulose:rhamnose ratio was higher in type 1 diabetes. Children with ≥2 IA who progressed to type 1 diabetes (progressors), compared to those who did not progress, had higher intestinal permeability (mean [SE] difference +5.14 [2.0], 95% confidence interval [CI] 1.21, 9.07, P = .006), lower within-sample (alpha) microbial diversity (31.3 [11.2], 95% CI 9.3, 53.3, P = .005), and lower abundance of SCFA-producing bacteria. Alpha diversity (observed richness) correlated with plasma acetate levels in all groups combined (regression coefficient [SE] 0.57 [0.21], 95% CI 0.15, 0.99 P = .008).

CONCLUSIONS/INTERPRETATION

Children with ≥2 IA who progress to diabetes, like those with recent-onset diabetes, have gut microbiome dysbiosis associated with increased intestinal permeability. Interventions that expand gut microbial diversity, in particular SCFA-producing bacteria, may have a role to decrease progression to diabetes in children at-risk.

Effect of glucose oxidase and pentosanase on the prebiotic potentials of wheat arabinoxylans in anin vitrofermentation system

GOX and Pn + GOX modification increased the prebiotic potential of WEAX. Pn + GOX treated WEAXs had higher prebiotic potentials than WEAXs treated with GOX. The prebiotic potential of the weak gel was higher than that in the strong gel.

Gene expression and morphological changes in the intestinal mucosa associated with increased permeability induced by short-term fasting in chickens

Short-term fasting for 4.5 and 9 hr has been demonstrated to increase intestinal permeability (IP) in chickens. This study aimed to investigate the effects of 0, 4.5, 9 and 19.5 hr fasting on intestinal gene expression and villus-crypt architecture of enterocytes in jejunal and ileal samples. On day 38, Ross-308 male birds were fasted according to their group and then euthanised. Two separate intestinal sections (each 2 cm long, jejunum and ileum) were collected. One section was utilised for villus height and crypt depth measurements. The second section was snap-frozen in liquid nitrogen for quantitative polymerase chain reaction (qPCR) analysis of tight junction proteins (TJP) including claudin-1, claudin-3, occludin, zonula occludens (ZO-1, ZO-2), junctional adhesion molecules (JAM) and E-cadherin. Additionally genes involved in enterocyte protection including glucagon-like peptide (GLP-2), heat-shock protein (HSP-70), intestinal alkaline phosphatase (IAP), mammalian target of rapamycin (mTOR), toll-like receptors (TLR-4), mucin (MUC-2), cluster differentiation (CD-36) and fatty acid-binding protein (FABP-6) were also analysed. Normally distributed data were analysed using one-way analysis of variance ANOVA. Other data were analysed by non-parametric one-way ANOVA. Villus height and crypt depth were increased (p < .05) only in the ileum after fasting for 4.5 and 9 hr compared with non-fasting group. mRNA expression of claudin-3 was significantly reduced in the ileum of birds fasted for 9 and 19.5 hr, suggesting a role in IP modulation. However, all other TJP genes examined were not statistically different from control. Nevertheless, ileal FABP-6 of all fasted groups was significantly reduced, which could possibly be due to reduced bile acid production during fasting.

Drug-development concepts as guides for optimizing clinical trials of supplemental zinc for populations at risk of deficiency or diarrhea

Studies on the efficacy of zinc supplementation for treatment or prevention of diarrhea have shown an inconsistent effect in populations at risk for zinc deficiency. Unlike drugs, which have no preexisting presence in the body, endogenous zinc must be assessed pharmacokinetically by isotope tracer studies. Although such methods have produced much data, very few studies have estimated the dose and the timing of dosing of zinc supplementation. This review examines drug kinetics used to establish the best dose, the timing of such doses, and the mechanism of action through pharmacodynamic markers and applies them, where possible, to zinc supplements. The findings reveal that little is known, especially in children at highest risk of zinc deficiency. Key data missing to inform proper dosing, whether for treatment of disease or for preventive nutrient supplementation, are noted. Addressing these uncertainties could improve study design, leading to future studies of zinc supplements that might be of greater benefit.

Reduced fasting periods increase intestinal permeability in chickens

Fasting of up to 24 hr has been shown to increase intestinal permeability (IP) in chickens. The aim of this study was to determine whether fasting duration of 4.5 and 9 hr increased IP and whether l-glutamine (a non-essential amino acid) supplementation before fasting provided some protection of barrier function as shown in other species. Ross 308 male broilers (n = 96) were fed either a control diet or the same diet supplemented with 1% glutamine from d0 to d38 post-hatch. On d37, the birds were assigned to single-bird metabolism cages and were fasted for either 0, 4.5, 9 or 19.5 hr. This study design was 2 × 4 factorial with two levels of glutamine and four levels of fasting. Birds in the 0-hr fasting group had free access to feed. All birds had ad libitum access to water. To measure IP on day 38, following their respective fasting periods, birds were administered two separate oral gavages of fluorescein isothiocyanate dextran (FITC-d) followed by lactulose, mannitol and rhamnose (LMR) sugars, 60 min apart. Whole blood was collected from the jugular vein 90 min post-LMR sugar gavage. FITC-d and L/M/R ratios were measured by spectrophotometry and high-performance ionic chromatography respectively. Lipopolysaccharide (LPS) endotoxins in plasma of the birds fed the control diet were also measured using chicken-specific LPS antibody ELISA. Serum FITC-d and plasma L/M and L/R ratios for 4.5, 9 and 19.5 hr were significantly (p < .05) higher compared to the non-fasting group. However, IP was not different in the glutamine-supplemented group (p > .05) compared to the control group. LPS concentrations measured by the ELISA were below the detectable range. We conclude that fasting periods of 4.5 and 9 hr increased IP compared to non-fasted birds and dietary glutamine supplementation did not ameliorate changes in IP.

New biomarkers for intestinal permeability induced by lipopolysaccharide in chickens

Intestinal health is influenced by a complex set of variables involving the intestinal microbiota, mucosal immunity, digestion and absorption of nutrients, intestinal permeability (IP) and intestinal integrity. An increase in IP increases bacterial or toxin translocation, activates the immune system and affects health. IP in chickens is reviewed in three sections. First, intestinal structure and permeability are discussed briefly. Second, the use of lipopolysaccharide (LPS) as a tool to increase IP is discussed in detail. LPS, a glycolipid found in the outer coat of mostly Gram-negative bacteria, has been reported to increase IP in rats, mice and pigs. Although LPS has been used in chickens for inducing systemic inflammation, information regarding LPS effects on IP is limited. This review proposes that LPS could be used as a means to increase IP in chickens. The final section focuses on potential biomarkers to measure IP, proposing that the sugar-recovery method may be optimal for application in chickens.

Gut permeability, its interaction with gut microflora and effects on metabolic health are mediated by the lymphatics system, liver and bile acid

There is evidence to link obesity (and metabolic syndrome) with alterations in gut permeability and microbiota. The underlying mechanisms have been questioned and have prompted this review. We propose that the gut barrier function is a primary driver in maintaining metabolic health with poor health being linked to ‘gut leakiness'. This review will highlight changes in intestinal permeability and how it may change gut microflora and subsequently affect metabolic health by influencing the functioning of major bodily organs/organ systems: the lymphatic system, liver and pancreas. We also discuss the likelihood that metabolic syndrome undergoes a cyclic worsening facilitated by an increase in intestinal permeability leading to gut dysbiosis, culminating in ongoing poor health leading to further exacerbated gut leakiness.

Zinc-fortified oral rehydration solution improved intestinal permeability and small intestinal mucosal recovery

A randomized double-blind placebo-controlled study was conducted in children admitted to hospital with gastroenteritis (≥3 loose stools per day). All were treated for 5 days following admission with either zinc (Zn, 3 mg) or without Zn-fortified rice-based oral rehydration solution (ORS). (13)C-sucrose breath test (SBT) and intestinal permeability (lactulose/rhamnose or L/R ratio) were performed concurrently prior to commencement of ORS with or without Zn and at day 5 post-admission. There was a significant improvement in the SBT results in both the Zn-fortified group, median (5th-95th percentile) 2.1% (0.4% to 8.3%) versus 4.4% (0.4% to 10.4%), P < .05, and control group, 1.4% (0.1% to 5.4%) versus 4.3% (0.4% to 11.4%), P < .05, between the day of admission and day 5 post-admission. In the Zn-fortified group, there was also a significant improvement in L/R ratio between the day of admission and day 5 post-admission, 53.0 (19.5-90.6) versus 17.7 (13.4-83.2), P < .05. Low levels of Zn improved intestinal permeability but did not enhance short-term recovery following diarrheal illness.

The potential for zinc stable isotope techniques and modelling to determine optimal zinc supplementation

It is well recognised that zinc deficiency is a major global public health issue, particularly in young children in low-income countries with diarrhoea and environmental enteropathy. Zinc supplementation is regarded as a powerful tool to correct zinc deficiency as well as to treat a variety of physiologic and pathologic conditions. However, the dose and frequency of its use as well as the choice of zinc salt are not clearly defined regardless of whether it is used to treat a disease or correct a nutritional deficiency. We discuss the application of zinc stable isotope tracer techniques to assess zinc physiology, metabolism and homeostasis and how these can address knowledge gaps in zinc supplementation pharmacokinetics. This may help to resolve optimal dose, frequency, length of administration, timing of delivery to food intake and choice of zinc compound. It appears that long-term preventive supplementation can be administered much less frequently than daily but more research needs to be undertaken to better understand how best to intervene with zinc in children at risk of zinc deficiency. Stable isotope techniques, linked with saturation response and compartmental modelling, also have the potential to assist in the continued search for simple markers of zinc status in health, malnutrition and disease.

Processing and storage of ratite oils affects primary oxidation status and radical scavenging ability

Treatments for diseases such as coronary artery disease and gastrointestinal disorders seek to minimise oxidative damage by free radicals through the use of antioxidants. Oils derived from ratites (flightless birds) have therapeutic potential, with varying fatty acid composition between species. The current study investigated the influence of farm location, rendering method, duration and storage mode on radical scavenging activity (RSA) and primary oxidation status of ratite oils. Emu Oil (n = 8; EO1, EO2a/b, EO3–7; varying processing and storage factors), Ostrich Oil (OsO), Rhea Oil (RO) and olive oil (OlO) were tested for free RSA against 2,2-diphenyl-1-picryl hydracyl (expressed as 1/IC50 g/mL) and primary oxidation (peroxide mEqO2/kg). RSA (g/mL) of EO1 (558 ± 22) was greater than EO2a (8 ± 0.6), EO5 (413 ± 26), EO6 (16 ± 0.3) and EO7 (2 ± 0.2), OsO (313 ± 12), RO (32 ± 12) and OlO (196 ± 4), and less than EO3 (717 ± 32; P < 0.001). Antioxidant properties of OsO were more pronounced than RO (P < 0.001). Primary oxidation (mEqO2/kg) of EO1 (97 ± 0.6) was greater than EO2a (57 ± 0.6), EO2b (28 ± 0.2), EO5 (11 ± 0.6), OsO (50 ± 0.9) and OlO (61 ± 0.9). The wide variability in RSA of oils highlights the need for standardisation of farm location, diet composition, rendering procedures, time of render and duration of storage. Regulatory control of these parameters is recommended in order to minimise differences in therapeutic efficacy of ratite oils.

Early life events influence whole-of-life metabolic health via gut microflora and gut permeability

The capacity of our gut microbial communities to maintain a stable and balanced state, termed 'resilience', in spite of perturbations is vital to our achieving and maintaining optimal health. A loss of microbial resilience is observed in a number of diseases including obesity, diabetes and metabolic syndrome. There are large gaps in our understanding of why an individual's co-evolved microflora consortium fail to develop resilience thereby establishing a trajectory towards poor metabolic health. This review examines the connections between the developing gut microbiota and intestinal barrier function in the neonate, infant and during the first years of life. We propose that the effects of early life events on the gut microflora and permeability, whilst it is in a dynamic and vulnerable state, are fundamental in shaping the microbial consortia's resilience and that it is the maintenance of resilience that is pivotal for metabolic health throughout life. We review the literature supporting this concept suggesting new potential research directions aimed at developing a greater understanding of the longitudinal effects of the gut microflora on metabolic health and potential interventions to recalibrate the 'at risk' infant gut microflora in the direction of enhanced metabolic health.

Emu oil expedites small intestinal repair following 5-fluorouracil-induced mucositis in rats

Mucositis resulting from cancer chemotherapy is characterized by intestinal inflammation and ulceration. Previously, emu oil (EO) improved intestinal architecture (Br J Nutr, 2010) in a rat model of chemotherapy-induced mucositis. We investigated EO for its further potential to promote intestinal repair in this mucositis model. Female Dark Agouti rats (n = 8/group) were gavaged with water, olive oil (OO) or EO once daily (1 mL), injected with 5-fluorouracil (5-FU) or saline on day 5 and euthanized on day 8, 9, 10 or 11. Intestinal villus height (VH) and crypt depth (CD), neutral mucin-secreting goblet cell (GC) count, myeloperoxidase (MPO) activity and selected cytokines were quantified; P < 0.05 was considered significant. In 5-FU-injected rats, only EO administration significantly increased VH in the ileum (day 8), jejunum and jejunum-ileum junction (days 8 and 9) compared to 5-FU controls (P < 0.05). GC count was significantly reduced by 5-FU (jejunum: days 8 and 9; ileum: day 8; P < 0.05) and EO increased ileal GC on days 10 and 11 compared to 5-FU controls. MPO activity was significantly increased in jejunum (days 8 and 9) and ileum (day 8) following 5-FU injection, compared to normal controls (P < 0.05). Both EO and OO significantly reduced jejunal MPO on days 8 and 9; however, only EO decreased ileal MPO on day 8. Cytokine levels were not significantly affected by either oil or 5-FU administration at the day 8 time point. Promotion of repair from injury could represent a new mechanism of action for EO, suggesting potential as an adjunct to conventional treatment approaches for cancer management.

Emu Oil: a novel therapeutic for disorders of the gastrointestinal tract?

Gastrointestinal diseases characterized by inflammation, including the inflammatory bowel diseases, chemotherapy-induced mucositis and non-steroidal anti-inflammatory drug-induced enteropathy, currently have variably effective treatment options, highlighting the need for novel therapeutic approaches. Recently, naturally-sourced agents including prebiotics, probiotics, plant-extracts and marine-derived oils known to possess anti-inflammatory and anti-oxidant properties have been investigated in vitro and in vivo. However, animal-derived oils are yet to be extensively tested. Emu Oil is extracted from the subcutaneous and retroperitoneal fat of the Emu, a flightless bird native to Australia, and predominantly comprises fatty acids. Despite the limited rigorous scientific studies conducted to date, with largely anecdotal claims, Emu Oil, when administered topically and orally, has been shown to possess significant anti-inflammatory properties in vivo. These include a CD-1 mouse model of croton oil-induced auricular inflammation, experimentally-induced polyarthritis and dextran sulfate sodium-induced colitis. Recently, Emu Oil has been demonstrated to endow partial protection against chemotherapy-induced mucositis, with early indications of improved intestinal repair. Emu Oil could therefore form the basis of an adjunct to conventional treatment approaches for inflammatory disorders affecting the gastrointestinal system.

Zinc homeostasis and gut function in children with celiac disease

BACKGROUND

Celiac disease (CD) is an immunologic enteropathy triggered by the intake of gluten. It is thought that the enteropathy impairs gut function and absorption.

OBJECTIVE

We assessed the zinc-absorption capacity and small-bowel integrity in children with CD.

DESIGN

Children in whom a diagnosis of CD was considered clinically and either confirmed (n = 16; Marsh score ≥3) or not (n = 22; Marsh score of 0) with a small-bowel biopsy (SBB) were recruited. The fractional absorption of zinc (FAZ) was determined by the administration of an oral (67)Zn dose (2.5 mg) and an intravenous (70)Zn dose (0.2 mg) 2 h before and during the SBB, respectively. Spot urine samples were collected, and zinc isotopic ratios were determined by ion-coupled plasma mass spectrometry. Gut health was assessed by the ingestion of (13)C-sucrose (20 g) after an overnight fast, and breath samples were collected and analyzed by isotope ratio mass spectrometry.

RESULTS

There was no difference in FAZ between children with a Marsh score ≥3 (mean ± SEM: 0.68 ± 0.05) and children with a Marsh score of 0 (0.74 ± 0.05). The exchangeable zinc pool (EZP) was significantly (P < 0.05) lower in children with a Marsh score ≥3 (2.6 ± 0.8 mg/kg) than in children with a Marsh score of 0 (3.8 ± 1.4 mg/kg). Gut function in children with a Marsh score ≥3 (4.5 ± 0.7% cumulative dose recovered at 90 min) was lower than the lower cutoff of a normal gut-function breath test (5.06% cumulative dose recovered at 90 min) but not significantly different from that in children with a Marsh score of 0 (4.9 ± 0.4%). There was a significant (P < 0.01) correlation between zinc absorption and gut function in children with CD.

CONCLUSIONS

Zinc absorption did not appear below usual amounts in subjects with CD. Children with CD have impaired gut function that may affect their zinc nutritional status as shown by a smaller EZP. However, the EZP decrease in children with CD was not compared with that in healthy control subjects, and its biological meaning is uncertain.

Dietary zinc and metallothionein on small intestinal disaccharidases activity in mice

AIM: To examine the effect of increasing dietary zinc (Zn) intake and the lack of metallothionein (MT) expression on activity of small intestinal disaccharidases.

METHODS: MT-I and II knockout (MT-/-) and wild-type (MT+/+) female mice at 3.5 wk of age were randomly fed with a diet containing 2 (2 Zn), 15 (15 Zn) or 50 (50 Zn) mg Zn/kg (n = 8/group/genotype) for 5 wk. Small intestinal segments (duodenum, jejunum and ileum) were collected and either fixed in 10% formalin for histological analysis or snap frozen in liquid nitrogen for sucrase, lactase and maltase activity analyses.

RESULTS: Plasma Zn was significantly (P < 0.05) lower (33%) in MT-/- compared with MT+/+ mice fed the 2 Zn diet. Villus height and crypt depth were increased by approximately 15% in MT+/+ mice compared with MT-/- mice. Duodenal disaccharidase activities were significantly higher in MT+/+ compared with MT-/- mice particularly in those fed the 2 Zn diet. For the 50 Zn diet, jejunal sucrase and lactase activities were significantly higher in MT-/- (13 313 ± 2314; 4107 ± 364 μmol glucose/well/min/g tissue, respectively) compared with MT+/+ mice (7054 ± 608; 1818 ± 174). Similarly, ileal lactase activities were higher in MT-/- (1480 ± 192) compared with MT+/+ (629 ± 353) mice particularly those fed the 2 Zn diet.

CONCLUSION: Increasing dietary Zn has little effect on disaccharidases activity in MT wild-type mice. The presence of MT may enhance morphological and functional development of the gut.

Novel combination therapy for the eradication of Helicobacter pylori infection in a mouse model

OBJECTIVE

To investigate the combination therapy, consisting of hyperimmune bovine colostrum, N-acetyl cysteine, zinc and amoxicillin on the eradication of Helicobacter pylori in a mouse model.

MATERIAL AND METHODS

C57BL/6 female mice (6 weeks of age) were inoculated with 0.1 ml of 1×10(9) H. pylori via a single oro-gastric gavage and were left infected for 4 weeks. Mice (n=9/group) were randomly allocated to receive by oral gavage (0.1 ml) HNZ (hyperimmune bovine colostrum+N-acetyl cysteine+zinc), HNZA (HNZ+amoxicillin; A), HNZA2 (2× amoxicillin; A2), HNZA5 (5× amoxicillin; A5), triple therapy (TT) or saline twice daily for 10 days. Bacterial load was assessed by culture. Gastric emptying was assessed by 13C-octanoic acid breath test.

RESULTS

Mice receiving HNZ, HNZA, and HNZA2 have a 22%, 44% and 67% eradication rate, respectively. Eradication rate was 100% with HNZA5, TT and those animals receiving A5 alone. In H. pylori infected mice there was an increased gastric emptying time by 7.9, 3.7, 10.1 and 7.7 min for the TT, HNZ, HNZA2, and HNZA5, respectively, compared to saline.

CONCLUSIONS

HNZ with the addition of a high dose of amoxicillin is effective at eradicating H. pylori in vivo as HNZA1 and HNZA2 did not give raise to eradication. The potency of the novel anti-H. pylori combination therapy may be due to the delayed gastric emptying.

Dietary zinc supplementation and methotrexate-induced small intestinal mucositis in metallothionein-knockout and wild-type mice

BACKGROUND

Chemotherapy-induced small intestinal mucositis is a debilitating side effect of cancer chemotherapy and currently there are no effective therapies. Zinc (Zn), an essential trace element required for normal growth and development and tissue repair processes, may be a potential treatment strategy. Zn induces metallothionein (MT) which has been shown to sequester free radicals. The aim of this study was to determine the capacity for dietary Zn supplementation to ameliorate methotrexate (MTX)-induced intestinal mucositis.

RESULTS

The duodenum and jejunum were significantly (p < 0.05) damaged at the 500 mg/kg MTX dose compared to 300 and 400 mg/kg MTX doses. Dietary Zn supplementation did not induce gut MT in MT(+/+) mice nor ameliorate MTX-induced gut damage in either MT(+/+) or MT(-/-) mice. However, MT(-/-) mice had markedly (p < 0.05) higher histological severity scores and MPO activity compared to MT(+/+) mice, irrespective of dietary Zn. methods: MT-knockout (MT(-/-)) and wild-type (MT(+/+)) mice were fed either a 10 mg/kg (control) or 400 mg/kg diet (high Zn) for 7 d and intestinal mucositis was induced by a single injection of MTX (500 mg/kg) subcutaneously. Mice were sacrificed at 24 and 72 h (n = 8/timepoint/genotype) after the MTX injection while continuing their respective diets. Daily weights were recorded and gut tissues were collected for histology, MT levels and myeloperoxidase (MPO) activity.

CONCLUSIONS

Dietary Zn supplementation did not ameliorate MTX-induced small bowel damage, possibly signifying a deficiency in induction of MT by Zn. However, the presence of MT was able to reduce histological damage and neutrophil infiltration caused by MTX in the gut.

13C-sucrose breath test: novel use of a noninvasive biomarker of environmental gut health

OBJECTIVE

Environmental enteropathy syndrome may compromise growth and predispose to infectious diseases in children in the developing world, including Australian Aboriginal children from remote communities of the Northern Territory. In this study, we described the use of a biomarker (13)C-sucrose breath test (SBT) to measure enterocyte sucrase activity as a marker of small intestinal villus integrity and function.

METHODS

This was a hospital-based prospective case-control study of Aboriginal and non-Aboriginal children with and without acute diarrheal disease. Using the SBT, we compared 36 Aboriginal case subjects admitted to a hospital (18 diarrheal and 18 nondiarrheal disease), with 7 healthy non-Aboriginal control subjects. Intestinal permeability using the lactulose/rhamnose (L/R) ratio on a timed 90-minute blood test was performed simultaneously with the SBT. The SBT results are expressed as a cumulative percentage of the dose recovered at 90 minutes.

RESULTS

Aboriginal children with acute diarrheal disease have a significantly decreased absorptive capacity, as determined by the SBT, with a mean of 1.9% compared with either Aboriginal children without diarrhea (4.1%) or non-Aboriginal (6.1%) control subjects. The mean L/R ratio in the diarrhea group was 31.8 compared with 11.4 in Aboriginal children without diarrhea. There was a significant inverse correlation between the SBT and the L/R ratio.

CONCLUSIONS

The SBT was able to discriminate among Aboriginal children with diarrhea, asymptomatic Aboriginal children with an underlying environmental enteropathy, and healthy non-Aboriginal controls. This test provides a noninvasive, easy-to-use, integrated marker of the absorptive capacity and integrity of the small intestine and could be a valuable tool in evaluating the efficacy of interventions aimed at improving gut health.

Lactoferrin and desferrioxamine are ineffective in the treatment of Helicobacter pylori infection and may enhance H. pylori growth and gastric inflammation in mice

AIMS

To evaluate the efficacy of bovine lactoferrin (BLf), recombinant human lactoferrin (rHLf) and desferrioxamine against Helicobacter pylori in vitro and in mice and also to determine whether BLf or rHLf alter gastric inflammation.

METHODS AND RESULTS

In vitro: Broth dilution susceptibility tests were performed using different concentrations of desferrioxamine, BLf and rHLf. Murine trials: In the prevention trial, C57BL/6 female mice were treated with BLf or rHLF, and then infected with the SS1 strain of H. pylori. In the treatment trial, mice were gavaged with either BLf, rHLf or desferrioxamine. In addition, gastric myeloperoxidase activity (MPO) was measured to assess gastric inflammation. Desferoxamine was found to have a direct bactericidal effect, while BLf and rHLf only partially suppressed H. pylori growth in vitro. However, in both prevention and treatment trials all three forms of treatment failed to reduce H. pylori load in mice. Gastric MPO activity and H. pylori load were noted to be higher with lactoferrin treatments.

CONCLUSIONS

Our study does not support the use of BLf or rHLF in the treatment of human H. pylori infection. Interestingly, H. pylori growth and gastric inflammation appear to be enhanced by lactoferrin treatment.

SIGNIFICANCE AND IMPACT OF THE STUDY

The mouse model is ideal for testing novel H. pylori eradicating agents.

Gastric emptying is altered with the presence of gastritis

Helicobacter pylori infection and gastritis can cause symptoms suggestive of altered gastrointestinal function; however, it is unclear if H. pylori influences gastric motility. This study assessed gastric emptying rates in mouse models of gastritis. Gastritis was induced in C57BL/6 mice via ethanol treatment or via challenge with H. pylori or H. felis. Gastric emptying rates of nutrient and non-nutrient liquids were assessed with the non-invasive (13)C-breath test, and the results were compared to healthy mice. Gastric emptying of the non-nutrient liquid was unaltered with the presence of gastritis; however, gastric emptying of the nutrient liquid was accelerated after a 4-week infection with H. pylori. H. felis infection and ethanol treatment caused a more severe gastritis and disruptions to the normal gastric emptying. Changes to gastric emptying in mouse models of gastritis are associated with the presence of nutrients. Altered gastric emptying may contribute to symptoms commonly reported in humans with gastritis.

Association between Helicobacter pylori infection in mothers and birth weight

Helicobacter pylori infection may cause intrauterine growth restriction (IUGR). However, it is unknown whether the growth of children from H. pylori-infected mothers is also affected or whether transmission of infection from mother to child occurs. This study aimed to determine if maternal H. pylori infection was associated with IUGR and low birth weight in a mouse model, and whether transmission of infection from mother to infant occurs. Female C57BL/6 mice were inoculated with H. pylori (n = 18) or water (control; n = 18) via gavage. Mice were mated at 6 weeks postinfection, with half of the mice sacrificed after 2 weeks of gestation. The remaining mice gave birth and a third of the litter was weighed and sacrificed at birth, during milk feeding (1.5 weeks), and during solid feeding (4 weeks). Stomachs of all mice and whole foetuses were cultured for the presence of H. pylori. There were no differences in litter size or foetus weight between control and H. pylori-infected mice. Pups from infected mothers had a lower weight during milk feeding (control, 5.91 +/- 0.23 g; H. pylori, 4.59 +/- 0.16 g; p < 0.05) and solid feeding (control, 12.73 +/- 0.58 g; H. pylori, 10.01 +/- 1.02 g; p < 0.05). H. pylori was not detected by culture in the pups at any age. H. pylori infection in mothers was associated with a decrease in infant weight during milk feeding and after weaning. Transmission of infection from mother to infant was not detected by culture, suggesting that decreased baby weight may be due to decreased milk supply or altered nutrition from the mother.

The role of zinc and metallothionein in the dextran sulfate sodium-induced colitis mouse model

Zinc (Zn) and its binding protein metallothionein (MT) have been proposed to suppress the disease activity in ulcerative colitis. To determine the role of Zn and MT in the dextran sulfate sodium (DSS)-induced model of colitis in mice, a DSS dose-response study was conducted in male C57BL/6 wild-type (MT+/+) and MT-null (MT-/-) mice by supplementing 2%, 3%, and 4% DSS in the drinking water for 6 days. In the intervention study, colitis was induced with 2% DSS, Zn (24 mg/ml as ZnO) was gavaged (0.1 ml) daily, concurrent with DSS administration, and the disease activity index (DAI) was scored daily. Histology, MT levels, and myeloperoxidase (MPO) activity were determined. DAI was increased (P<0.05) by 16% and 21% with 3% and 4% concentrations of DSS, respectively, compared to 2%, evident after 5 days of DSS administration. MPO activity was increased in MT+/+ compared to MT-/- mice and those receiving DSS. Zn administration had a 50% (P<0.05) lower DAI compared to DSS alone. Zn partially prevented the distal colon of MT+/+ by 47% from DSS-induced damage compared to MT-/- mice. MT did not prevent DSS-induced colitis and Zn was partially effective in amelioration of DSS-induced colitis.

Metallothionein expression in Helicobacter-infected pregnant mice and their fetuses and pups

Metallothionein (MT) expression was investigated in pregnant mice infected with H. pylori or H. felis and their fetuses and pups. Mice, healthy or infected with H. pylori or H. felis (n = 18/group), were sacrificed 2 weeks after impregnation or 4 weeks postpartum. Pups were sacrificed as fetuses, after birth, or at ages 11 or 28 days. Whole fetuses, stomachs, small intestines, and livers were assayed for MT. MT was increased (P<0.05) by two- and threefold in fetuses from H. pylori- and H. felis-infected mothers, respectively, compared to control fetuses. Stomach MT of H. felis-infected pregnant mice, and newborns and 28-day pups from H. felis-infected mothers, was elevated (P<0.05) twofold compared to that of control mice and pups. Liver MT was decreased (P<0.05) in H. felis-infected mice 4 weeks postpartum (18%) and in their 11-day (69%) and 28-day (53%) pups, while small intestinal MT was decreased in H. felis-infected pregnant mice (17%), H. felis-infected mice 4 weeks postpartum (19%), and their 11-day pups (35%), compared to control mice. H. felis infection altered MT levels of pregnant mice, their fetuses and pups, and mice postpartum, which may be a response to the marked inflammation.

Measurements of Zinc Absorption: Application and Interpretation in Research Designed to Improve Human Zinc Nutriture

The focus of this paper is on the application of measurements of zinc absorption in human research, especially studies designed to assess the efficacy of intervention strategies to prevent and manage zinc deficiency in populations. Emphasis is given to the measurement of quantities of zinc absorbed rather than restricting investigations to measurements of fractional absorption of zinc. This is especially important when determining absorption of zinc from the diet, whether it be the habitual diet or an intervention diet under evaluation. Moreover, measurements should encompass all meals for a minimum of one day with the exception of some pilot studies. Zinc absorption is primarily via an active saturable transport process into the enterocytes of the proximal small intestine. The relationship between quantity of zinc absorbed and the quantity ingested is best characterized by saturable binding models. When applied to human studies that have sufficient data to examine dose-response relationships, efficiency of absorption is high until approximately 50–60% maximal absorption is achieved, even with moderate phytate intakes. This also coincides approximately with the quantity of absorbed zinc necessary to meet physiologic requirements. Efficiency of absorption with intakes that exceed this level is low or very low. These observations have important practical implications for the design and interpretation of intervention studies to prevent zinc deficiency. They also suggest the potential utility of measurements of the quantity of zinc absorbed when evaluating the zinc status of populations.

Short-term zinc supplementation attenuates Helicobacter felis-induced gastritis in the mouse

BACKGROUND

Mucosal damage by H. pylori infection is mainly caused by neutrophils producing large quantities of reactive oxygen species (ROS). Metallothionein (MT) an intracellular, low-molecular, cysteine-rich protein, which is inducible by dietary zinc (Zn), has been implicated in sequestering ROS. This study examines the effects of Zn supplementation on Helicobacter colonisation and associated gastritis and the relationship with gastric MT levels.

METHODS

C57Bl/6 mice were inoculated with either 10(8) H. pylori or H. felis and were infected for 4 weeks or 6 and 12 weeks, respectively. Mice infected with H. pylori (4 weeks) or H. felis (6 weeks) were treated with either Zn acetate (ZnA; 1 mg/ml), or Zn sulphate (ZnSO4; 5 mg/ml) for 2 weeks with 0.1 ml oro-gastric gavage twice daily. H. pylori load and H. felis colonisation density were determined by culture and microscopy, respectively. MT levels and H. felis-induced gastritis were also determined.

RESULTS

Zn treatment showed no significant difference in Helicobacter load and gastric MT, however, ZnSO4 treatment showed a significant (p<0.05) increased in gastric MT in H. felis infected mice. Both Zn-treated groups showed a significant (p<0.05) difference in gastritis score in the antrum of the stomach within the basal and submucosal compartments compared to H. felis-infected controls.

CONCLUSIONS

We found that H. felis-induced gastritis can be attenuated by short-term treatment of Zn. This observation suggests that Zn alone may be effective for the suppression of gastric mucosal inflammation induced by Helicobacter.

Zinc absorption as a function of the dose of zinc sulfate in aqueous solution

BACKGROUND

Zinc supplements are used extensively in medicine and research and for public health purposes in the prevention and treatment of zinc deficiency. However, little is known about the efficiency of zinc utilization after different doses.

OBJECTIVE

The objective was to determine the relation between dose of aqueous zinc and absorbed zinc (AZ) in healthy adults.

DESIGN

Eight healthy adults (3 men and 5 women) aged 33.8 +/- 9.8 y (x +/- SD) received 3 pairs of zinc doses (2 and 5, 10 and 15, and 20 and 30 mg) in random order in 3 phases (1 pair per phase). There was a 3-wk washout between phases. Aqueous zinc sulfate labeled with 70Zn or 68Zn was orally administered in the postabsorptive state on days 1 and 6, respectively; intravenous 67Zn was administered 1 h after the first oral zinc dose. Two urine samples were collected daily from days 3 to 15; zinc isotopic ratios were determined by inductively coupled plasma mass spectrometry. Fractional absorption of zinc (FAZ) was determined by dual-isotope-tracer ratio; AZ was calculated by multiplying FAZ by dose.

RESULTS

Mean (+/-SD) AZ values at doses of 2.2, 5.2, 10.4, 15.2, 20.3, and 30.1 mg ingested Zn were 1.6 +/- 0.4, 3.5 +/- 1.3, 7.4 +/- 1.0, 9.5 +/- 2.2, 11.0 +/- 4.4, and 11.2 +/- 2.1 mg, respectively. A saturable dose-response model, the Hill equation, was selected to model the relation of AZ to ingested zinc. Parameter estimation by nonlinear regression predicted a maximum zinc absorption of 13 mg for larger doses.

CONCLUSIONS

Increases in aqueous zinc doses >20 mg result in relatively small and progressively diminishing increases in AZ postabsorptively in healthy adults.

N-acetylcysteine, a novel treatment for Helicobacter pylori infection

N-Acetylcysteine (NAC), being both a mucolytic agent and a thiol-containing antioxidant, may affect the establishment and maintenance of H. pylori infection within the gastric mucus layer and mucosa. Agar and broth dilution susceptibility tests determined the MIC of H. pylori strain SSI to NAC. H. pylori load in SSI strain-infected C57BL mice was determined as colony forming units per gram of gastric tissue. Gastritis assessment was scored and gastric surface hydrophobicity was determined by contact angle measurement. MICs of NAC were 5 to 10 and 10 to 15 mg/ml using the agar dilution and broth dilution methods, respectively. NAC (120 mg per day for 14 days) reduced the H. pylori load in mice by almost 1 log compared with sham treatment. Pretreatment with NAC (40 mg/day) also significantly reduced the H. pylori load but did not prevent H. pylori colonization. Both H. pylori infection and NAC reduced the surface hydrophobicity of murine gastric mucosa. No significant differences were observed in the gastritis scores of H. felis- or H. pylori-infected mice receiving either NAC or sham treatments. This study demonstrates that NAC inhibits the growth of H. pylori in both agar and broth susceptibility tests and in H. pylori-infected mice. NAC did not alter the severity of H. pylori- or H. felis-induced gastritis.

Helicobacter-induced gastritis in mice not expressing metallothionein-I and II

BACKGROUND

Helicobacter pylori a primary cause of gastritis and peptic ulcer disease, is associated with increased production of reactive oxygen species within the gastric mucosa. Metallothionein (MT), a low-molecular-weight, cysteine-rich, metal-binding ligand, has been shown to sequester reactive oxygen species and reduce tissue damage. This study investigates the role of MT in H. pylori-induced gastritis in mice.

MATERIALS AND METHODS

Control (MT+/+) and MT-null (MT-/-) mice were inoculated with either 1 x 108H. pylori or H. felis, and were infected for 4, 8 and 16 weeks or 8 weeks, respectively. H. pylori load was determined by culture. Myloperoxidase activity and MT levels were also determined.

RESULTS

The stomachs of H. felis-infected mice were more severely inflamed than those of H. pylori-infected mice. H. felis-induced gastritis was more severe (p =.003) in MT-/- than in MT+/+ mice. MT-/- mice also had higher (60%; p <.05) H. pylori loads than MT+/+ mice 4 weeks after infection but not 8 or 16 weeks after infection. Myloperoxidase activity with H. pylori was similar between MT+/+ and MT-/- mice. Thirty-three per cent greater (p <.05) myloperoxidase activity was observed in MT-/- than in MT+/+ mice infected with H. felis. In MT+/+ mice infected with H. pylori, liver MT was increased by 33 and 39% (p <.05) at 8 and 16 weeks, respectively, whereas gastric MT increased by 46% (p <.05) at 4 weeks and declined to baseline levels at 8 and 16 weeks.

CONCLUSIONS

Mice lacking MT are more susceptible to H. pylori colonization and gastric inflammation, indicating that MT may be protective against H. pylori-induced gastritis.

Analytical methods: improvements, advancements and new horizons

The workshop and exhibits dealing with analytical methods were selected to highlight the current state of the art in elemental analysis. The presentations in the first part of the workshop described approaches and advances important to the analysis of trace minerals. These presentations included: 1) two approaches to mass spectrometry, inductively coupled plasma and accelerator mass spectrometry; 2) use of nuclear magnetic resonance in studies of mineral function; and 3) the use and limitations of fluorescent probes in studies of metal uptake and regulation. In the second part of the workshop, the International Atomic Energy's contributions to nutritional "metrology" were described. Advances in instrumentation over the past decade have led to extraordinary improvements in the precision and sensitivity of mineral analyses. The ability to address isotopic speciation at such low levels sets the stage for numerous novel approaches in the assessment of trace mineral function.

Dietary supplementation with zinc and a growth factor extract derived from bovine cheese whey improves methotrexate-damaged rat intestine

BACKGROUND

Oral administration of zinc or bovine whey-derived growth factor extract (WGFE) is known to reduce intestinal permeability and ameliorate methotrexate (MTX)-induced mucositis, respectively.

OBJECTIVE

We examined the effects of zinc, WGFE, and zinc plus WGFE on gut damage in MTX-treated rats.

DESIGN

Rats (n = 16/group) were fed zinc (1000 mg/kg diet), WGFE (32 mg/kg diet), zinc plus WGFE, or control (10 mg Zn/kg diet) diets for 7 d and then injected subcutaneously with MTX (2.5 mg/kg) for 3 d to induce gut damage. Gut histology and intestinal permeability were assessed.

RESULTS

The Zn+WGFE diet was associated with both reduced gut damage on day 5 and enhanced recovery on day 7. The WGFE diet ameliorated gut damage, whereas the Zn and Zn+WGFE diets enhanced repair. Gut metallothionein and tissue zinc concentrations were significantly (P < 0.01) higher with Zn and Zn+WGFE on days 5 and 7 than without zinc supplementation. The Zn and Zn+WGFE diets significantly (P < 0.05) decreased gut permeability on days 3-4 compared with the control diet. Intestinal permeability was significantly (P < 0.05) increased on days 5-6. On days 6-7, only the WGFE diet improved gut permeability (by 80%) compared with the control diet.

CONCLUSIONS

Dietary administration of WGFE and a pharmacologic dose of zinc reduced intestinal damage and enhanced recovery, respectively. WGFE also improved gut permeability after MTX-induced bowel damage. In combination, zinc and WGFE hastened repair of gut damage, which may have clinical application in chemotherapy-induced mucositis.

Near-infrared spectrometric determination of di- and tripeptides synthesized by a combinatorial solid-phase method

A new method based on near-infrared (NIR) spectrometry and partial least-squares analysis has been developed for the noninvasive and nondestructive determination of the identity and sequences of amino acid residues in di- and tripeptides. The di- and tripeptides were synthesized from six amino acids with similar structures (Gly, Ala, Leu, Met, Phe, Val) on two different polymer beads (bead with and without a linker) using the solid-phase peptide synthetic method. The developed NIR method is capable of determining the identity of sequences of these di- and tripeptides (with and without the Fmoc protecting group) directly on the polymer beads. It can distinguish not only dipeptides from tripeptides but also peptides with very similar structures (e.g., bead-Gly-Ala-Ala, bead-Gly-Ala-Phe, bead-Gly-Ala-Leu, bead-Gly-Ala-Val, and bead-Gly-Ala-Met). More importantly, the method is capable of distinguishing di- and tripeptides with the same amino acid residues but different sequences (e.g., bead-Gly-Leu-Val from bead-Gly-Val-Leu).

Multispectral imaging microscope with millisecond time resolution

A new multispectral imaging microscope with micrometer spatial resolution and millisecond temporal resolution has been developed. The imaging microscope is based on the use of an acousto-optic tunable filter (AOTF) for spectral tuning and a progressive scan camera capable of snapshot operation for recording. It can operate in two modes: images are recorded as a function of time or wavelength. When operated as a function of time, the microscope is configured so that as many images as possible are recorded, grabbed, and stored per one wavelength. Upon completion, the AOTF is scanned to a new wavelength, and a new set of images are recorded. Up to 33 images/ second (i.e., 30 ms/image) can be recorded in this mode. In the other configuration, the recording wavelength is rapidly scanned (by means of the AOTF) and only one image is rapidly recorded, grabbed, and stored for each wavelength. Because additional time is needed to scan the AOTF, the maximum number of images can be grabbed in this case is 16 frames/s. Preliminary applications of the imaging microscope include measurements of photoinduced changes of a single unit cell in temperature-sensitive cholesteric liquid crystals as a function of time and wavelength. The changes were found to be varied with time and wavelength. Interestingly, the photoinduced changes of unit cells in the liquid crystal are not the same but different from cell to cell. This imaging microscope is particularly useful for measurements of small-size samples that undergo rapid chemical or biochemical reactions, e.g., activities of a single biological cell.

Development and analytical applications of multispectral imaging techniques: an overview

A multispectral imaging spectrometer is an instrument that can simultaneously record spectral and spatial information of a sample. Chemical and physical properties of the sample can be elucidated from such images. By synergistic use of an acousto-optic tunable filter and a progressive scan camera capable of snap shot recording it was possible to develop a novel imaging spectrometer with a spatial resolution of a few microns and which can record, grab and store up to 33 images per second (at a function of time) or 16 images per second (as a function of wavelength). This overview article summarizes the instrumentation development of various imaging spectrometers and their applications including its use as the detector for the determination of identity and sequences of peptides synthesized by the combinatorial solid phase method.

Thermal-Lens-Induced Anomalous Solvent's effect on Fluorescence Produced by Two-Photon Continuous-Wave Laser Excitation

Measurements of two-photon-excited fluorescence (TPF) of fluorescein and Rhodamine 6G in various solvents were performed with a continuous-wave (cw) laser for excitation and an acousto-optic tunable filter for spectral dispersion. Interestingly, the cw laser excitation produced an unwanted thermal-lens effect when the measurements were performed in solvents that absorb the excitation laser light (e.g., alcohols and water, because these solvents absorb the 780-nm excitation light through the overtone and combination transitions of the O-H group). The defocusing effect of the thermal lens leads to a decrease in the TPF signal. Because the strength of the thermal lens depends on the thermo-optical properties (dn/dT and thermal conductivity) of the solvent, its interference makes the effect of solvents on the TPF much different from those on one-photon-excited fluorescence. However, the thermal-lens interference will not limit the application of this cw laser excited TPF technique because, even when measurements were performed in solvents that absorb cw excitation laser light, the thermal-lens interference was observed only in solvents such as nonpolar organic solvents that have relatively better thermo-optical properties. Interference was not observed in water, which is the most widely used solvent for the TPF technique (because water has poor thermo-optical properties).