Standardization of radiograph readings during bowel management week.

INTRODUCTION: During "bowel management week," abdominal radiographs are used to monitor the amount and location of stool. A radiologist familiar with the treatment plan can provide an improved interpretation. The goal of this paper is to standardize the radiological reports during a bowel management week. METHODS: We saw 744 patients during bowel management week from May 2016 until March 2023. Diagnosis included: anorectal malformation (397), idiopathic constipation (180), Hirschsprung disease (89), and spina bifida (78). Laxatives were the treatment for 51% of patients, and 49% received enemas. Characteristic radiographs were selected for each treatment group for a proposed reading standardization. RESULTS: When the stool is visualized, it is crucial to report its location. Having a contrast enema helps with the correct interpretation of the colonic anatomy. It is also essential to always compare the amount of stool with the radiograph from the previous day to determine if there is an increase or decrease in stool. Examples of radiographs are shown to guide the use of the preferred proposed terminology. CONCLUSION: Providing information regarding which treatment modality the patient is receiving and stating that a patient is on a bowel management week treatment is crucial for the radiologist to provide adequate interpretation. The radiologist must be familiar with the treatment goals and purpose of the daily radiograph.

Beyond expectations: the physiological basis of sensory enhancement of satiety.

BACKGROUND/OBJECTIVES: Consumption of high-energy beverages has been implicated as a risk factor for weight gain, yet why nutrients ingested as beverages fail to generate adequate satiety remains unclear. In general, consumers do not expect drinks to be satiating, but drinks generate greater satiety when their sensory characteristics imply they may be filling. These findings challenge traditional bottom-up models of how gut-based satiety signals modify behaviour to suggest that beliefs at the point of ingestion modify gut-based satiety signalling. SUBJECTS/METHODS: Healthy volunteers (n=23) consumed four different beverages, combining an overt sensory manipulation (thin, low sensory (LS) or thicker and more creamy, enhanced sensory (ES)) and covert nutrient manipulation (low energy (LE), 78 kcal; high energy (HE), 267 kcal) on different days. Effects on satiety were assessed through rated appetite and levels of glucose, insulin, pancreatic polypeptide (PP) and cholesystokinin (CCK) recorded periodically over 90 min, and through intake at an ad libitum test lunch. RESULTS: Intake at the test lunch and rated appetite were both altered by both the sensory and nutrient manipulations, with lowest intake and greatest suppression of hunger post-drink in the ESHE condition. Insulin increased more after HE than LE drinks, and after ES than LS drinks, whereas PP levels were higher after ES than LS versions. CCK levels only increased after the ESHE drink. CONCLUSIONS: These data confirm acute sensitivity of satiety after consuming a drink both to the sensory characteristics and nutrient content of the drink, and suggest that this may be, at least in part, due to top-down modulation of release of satiety-related gut hormones.

Digestion of starch in a dynamic small intestinal model.

PURPOSE: The rate and extent of starch digestion have been linked with important health aspects, such as control of obesity and type-2 diabetes. In vitro techniques are often used to study digestion and simulated nutrient absorption; however, the effect of gut motility is often disregarded. The present work aims at studying fundamentals of starch digestion, e.g. the effect of viscosity on digestibility, taking into account both biochemical and engineering (gut motility) parameters. METHODS: New small intestinal model (SIM) that realistically mimics gut motility (segmentation) was used to study digestibility and simulated oligosaccharide bio accessibility of (a) model starch solutions; (b) bread formulations. First, the model was compared with the rigorously mixed stirred tank reactor (STR). Then the effects of enzyme concentration/flow rate, starch concentration, and digesta viscosity (addition of guar gum) were evaluated. RESULTS: Compared to the STR, the SIM showed presence of lag phase when no digestive processes could be detected. The effects of enzyme concentration and flow rate appeared to be marginal in the region of mass transfer limited reactions. Addition of guar gum reduced simulated glucose absorption by up to 45 % in model starch solutions and by 35 % in bread formulations, indicating the importance of chyme rheology on nutrient bioaccessibility. CONCLUSIONS: Overall, the work highlights the significance of gut motility in digestive processes and offers a powerful tool in nutritional studies that, additionally to biochemical, considers engineering aspects of digestion. The potential to modulate food digestibility and nutrient bioaccessibility by altering food formulation is indicated.

Trajectories of childhood neighbourhood cohesion and adolescent mental health: evidence from a national Canadian cohort.

BACKGROUND: The objective of this study was to examine associations between trajectories of childhood neighbourhood social cohesion and adolescent mental health and behaviour. METHOD: This study used data from the National Longitudinal Survey of Children and Youth, a nationally representative sample of Canadian children. The sample included 5577 children aged 0-3 years in 1994-1995, prospectively followed until age 12-15 years. Parental perceived neighbourhood cohesion was assessed every 2 years. Latent growth class modelling was used to identify trajectories of neighbourhood cohesion. Mental health and behavioural outcomes were self-reported at age 12-15 years. Logistic regression was used to examine associations between neighbourhood cohesion trajectories and outcomes, adjusting for potential confounders. RESULTS: Five distinct trajectories were identified: 'stable low' (4.2%); 'moderate increasing' (9.1%); 'stable moderate' (68.5%); 'high falling' (8.9%); and 'stable high' (9.3%). Relative to those living in stable moderately cohesive neighbourhoods, those in stable low cohesive neighbourhoods were more likely to experience symptoms of anxiety/depression [odds ratio (OR) = 1.73, 95% confidence interval (CI) 1.04-2.90] and engage in indirect aggression (OR = 1.62, 95% CI 1.07-2.45). Those with improvements in neighbourhood cohesion had significantly lower odds of hyperactivity (OR = 0.67, 95% CI 0.46-0.98) and indirect aggression (OR = 0.69, 95% CI 0.49-0.96). In contrast, those with a decline in neighbourhood cohesion had increased odds of hyperactivity (OR = 1.67, 95% CI 1.21-2.29). Those in highly cohesive neighbourhoods in early childhood were more likely to engage in prosocial behaviour ('high falling': OR = 1.93, 95% CI 1.38-2.69; 'stable high': OR = 1.89, 95% CI 1.35-2.63). CONCLUSIONS: These results suggest that neighbourhood cohesion in childhood may have time-sensitive effects on several domains of adolescent mental health and behaviour.

Antimicrobial potential of polyphenols extracted from almond skins.

AIMS: To evaluate the antimicrobial properties of flavonoid-rich fractions derived from natural and blanched almond skins, the latter being a by-product from the almond processing industry. METHODS AND RESULTS: Almond skin extracts were tested against Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Serratia marcescens), Gram-positive bacteria (Listeria monocytogenes, Enterococcus hirae, Staphylococcus aureus, Enterococcus durans) and the yeast Candida albicans. Almond skin fractions were found to have antimicrobial activity against L. monocytogenes and Staph. aureus in the range 250-500 microg ml(-1), natural skins showing antimicrobial potential against the Gram-negative Salm. enterica. The interactions between three almond skin flavonoids were also evaluated with isobolograms. CONCLUSIONS: Pairwise combinations of protocatechuic acid, naringenin and epicatechin showed both synergistic and indifferent interactions against Salm. enterica and Staph. aureus. Antagonism was observed against L. monocytogenes with all combinations tested. Further studies need to be performed to understand the mechanisms responsible for these interactions. SIGNIFICANCE AND IMPACT OF THE STUDY: Almond skins are a potential source of natural antimicrobials.

Silicon identification in prosthesis-associated fibrous capsules.

The use of correlated microscopic techniques, including the scanning electron microscopic modes of backscattered electron imaging and energy dispersive x-ray analysis, aid in defining the process of dispersion of silicon-containing material around silicone rubber (polydimethylsiloxane) prosthetic devices.

In vitro digestibility of beta-casein and beta-lactoglobulin under simulated human gastric and duodenal conditions: a multi-laboratory evaluation.

Initially the resistance to digestion of two cow's milk allergens, beta-casein, and beta-lactoglobulin (beta-Lg), was compared using a "high-protease assay" and a "low-protease assay" in a single laboratory. The low-protease assay represents an alternative standardised protocol mimicking conditions found in the gastrointestinal tract. For the high-protease assay, both proteins were incubated with either pepsin or pancreatin and digestion monitored by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse phase-high performance liquid chromatography. The low-protease assay involved gastroduodenal digestion in the presence or absence of phosphatidylcholine (PC). Both beta-casein and beta-Lg were susceptible to hydrolysis by pepsin and pancreatin in the high-protease assay. In contrast, the kinetics of beta-casein digestion in the low-protease assay were slower, beta-Lg being pepsin resistant. During duodenal digestion, beta-Lg was gradually degraded and addition of PC slowed digestion. Subsequently, the reproducibility of the low-protease assay was assessed in 12 independent laboratories by visual assessment of the gels and densitometric analysis: the inter- and intra-laboratory variability was affected by sampling and electrophoresis method employed. The low-protease assay was shown to be reproducible. Future studies will extend these findings using a broader panel of proteins.

Potential prebiotic properties of almond (Amygdalus communis L.) seeds.

Almonds are known to have a number of nutritional benefits, including cholesterol-lowering effects and protection against diabetes. They are also a good source of minerals and vitamin E, associated with promoting health and reducing the risk for chronic disease. For this study we investigated the potential prebiotic effect of almond seeds in vitro by using mixed fecal bacterial cultures. Two almond products, finely ground almonds (FG) and defatted finely ground almonds (DG), were subjected to a combined model of the gastrointestinal tract which included in vitro gastric and duodenal digestion, and the resulting fractions were subsequently used as substrates for the colonic model to assess their influence on the composition and metabolic activity of gut bacteria populations. FG significantly increased the populations of bifidobacteria and Eubacterium rectale, resulting in a higher prebiotic index (4.43) than was found for the commercial prebiotic fructooligosaccharides (4.08) at 24 h of incubation. No significant differences in the proportions of gut bacteria groups were detected in response to DG. The increase in the numbers of Eubacterium rectale during fermentation of FG correlated with increased butyrate production. In conclusion, we have shown that the addition of FG altered the composition of gut bacteria by stimulating the growth of bifidobacteria and Eubacterium rectale.

A homologue of Sar1p localises to a novel trafficking pathway in malaria-infected erythrocytes.

We have identified a homologue of the GTP-binding protein, Sar1p, in Plasmodium falciparum. Sar1p is a small GTPase that is thought to play a crucial role in trafficking of proteins between the endoplasmic reticulum and the Golgi. The P.falciparum SAR1 gene is located on chromosome 4 and comprises two exons separated by a 508 bp intron. The deduced amino acid sequence of PfSar1p (GenBank accession number AF104306) shows 71% similarity (58% identity) to Sar1p from Saccharomyces cerevisiae. Expression of PfSar1p in erythrocytic stages of P. falciparum was confirmed by sequencing of a tryptic peptide derived from a polypeptide excised from an SDS-polyacrylamide gel. A recombinant protein corresponding to approximately 70% of the PfSar1p sequence was used to raise antibodies. The affinity-purified antiserum recognised a protein with an apparent molecular weight of 23 K in Western blots of malaria-infected erythrocytes but not in uninfected erythrocytes. PfSar1p was shown to be largely insoluble in non-ionic detergent and a low ionic strength buffer. Confocal immunofluorescence microscopy of malaria-infected erythrocytes was used to show that PfSar1p is located near the periphery of the parasite in discrete compartments, which appear to be distinct from the parasite endoplasmic reticulum. In addition, PfSar1p appears to be exported to structures outside the parasite in the erythrocyte cytoplasm. The export of PfSar1p to the erythrocyte cytosol is inhibited by treatment with brefeldin A. This provides the first evidence that the malaria parasite is capable of elaborating components of the classical vesicle-mediated trafficking machinery outside the boundaries of its own plasma membrane.

Functional analysis of proteins involved in Plasmodium falciparum merozoite invasion of red blood cells.

Plasmodium falciparum causes the most lethal form of malaria in humans and is responsible for over two million deaths per year. The development of a vaccine against this parasite is an urgent priority and potential protein targets include those on the surface of the asexual merozoite stage, the form that invades the host erythrocyte. The development of methods to transfect P. falciparum has enabled the construction of gain-of-function and loss-of-function mutants and provided new strategies to analyse the role of parasite proteins. In this review, we describe the use of this technology to examine the role of merozoite antigens in erythrocyte invasion and to address their potential as vaccine candidates.

Immobilization of viral antigens on filter paper for a [125I]staphylococcal protein A immunoassay: a rapid and sensitive technique for detection of herpes simplex virus antigens and antiviral antibodies.

A new technique is described for the rapid detection and quantitation of herpes simplex virus (HSV) antigens and antiviral antibodies. It involves immobilization of HSV antigens on filter paper discs and subsequent analysis by 125I-labeled staphylococcal protein A (SPA) radioimmunoassay. A specially designed 96-well filtration device is employed which serves both as an incubation chamber and as a filtration manifold. It is rapid, simple, sensitive and specific, and requires only small volumes of antiserum and few target cells. The results may be readily and objectively quantitated. This technique permits the simultaneous assay of a large number of specimens in less than 1 h. Its sensitivity is considerably greater than that of other currently used immunologic techniques, and it is amenable to automation. These characteristics suggest that this [125I]SPA immunofiltration technique may be applicable to the rapid diagnosis of viral infections.

The chromosomal organization of the Plasmodium falciparum var gene family is conserved.

The var gene family of Plasmodium falciparum encodes the protein PfEMP1 which is located on the surface of infected erythrocytes and is the receptor that mediates binding to ligands on endothelial cells. This family of proteins is responsible for antigenic variation and differences in binding phenotype to ligands such as CD36 and ICAM1. We have compared the organization of the var gene family in three in vitro cloned lines of P. falciparum and show that most var genes are located in the subtelomeric region of each chromosome closely linked to the repetitive sequence rep20. While most chromosomes possess var genes in the subtelomeric region, in each in vitro cloned line there are some chromosomes that have deleted subtelomeric repetitive regions which include var genes. Comparison of the location of var genes in a field isolate showed that it does not have any detectable subtelomeric deletions as all chromosomes contain var genes and rep20 sequences. We have detected three chromosomes (4, 7 and 12) that contain var gene loci in more stable central regions and the position of these genes on chromosome 4 in the cloned lines analysed is conserved. The location of most of the var gene family in the subtelomeric region of the genome of P. falciparum has important implications for the generation of antigenic diversity of the PfEMP1 protein.

Multiple var gene transcripts are expressed in Plasmodium falciparum infected erythrocytes selected for adhesion.

Adherence of Plasmodium falciparum-infected erythrocytes to the post-capillary endothelium is an important characteristic of malaria infection. The adhesion is mediated predominantly by P. falciparum Erythrocyte Membrane Protein-1 (PfEMP1), a clonally variant protein expressed on the surface of infected red blood cells that appears to be a target of protective immunity. A multi-membered var gene family encodes PfEMP1 and switching expression of different var genes conveys different antigenic and adhesive properties to infected red blood cells. Knowledge about transcriptional control of phenotypic expression, or the mechanisms that allow multiple binding specificities, is very limited. Here, we describe a series of phenotypic selection experiments, which resulted in the expression of different PfEMP1 and the detection of multiple full-length var gene transcripts in the mature trophozoite stage. However, a dominant form of PfEMP1 appeared to be expressed, which suggested that most var transcripts do not lead to a surface expressed PfEMP1 molecule. Parasites bound to specific receptors still expressed multiple full-length var genes and mature trophozoites selected for increased adhesion to a specific receptor retained the ability to bind to multiple receptors. Our findings suggest that a defined adhesive phenotype can be associated with expression of multiple var genes.

M-K medium and postmortem cytologic damage.

Freshly enucleated rabbit eyes were refrigerated at +4 degrees C under standard eye bank conditions for 2, 6, 9, and 21 days. One group of corneas with a scleral rim were excised and placed in M-K medium, stored for 18, 24, or 48 hr at +4 degrees C; they were then removed, and endothelial cell viability was evaluated with nitroblue tetrazolium. The cells were examined by light microscopy and scanning and transmission electron microscopy. A second group of corneas were similarly obtained and then used as donor corneas from 6 mm transplants. Each recipient rabbit was evaluated daily by slit-lamp biomicroscopy and corneal pachometry. Fourteen days postoperatively, the rabbits were sacrificed, the eyes enucleated, and the excised corneas were evaluated in a fashion similar to those of group 1. M-K medium storage protected the morphology and functional integrity of the rabbit corneal endothelium up to 48 hr beyond moist chamber storage for 2, 6, and 9 days. However, M-K medium appeared to have no such effect on corneas that had been moist chamber--stored for 21 days. These results suggest that some human corneas with a prolonged time from death to moist chamber storage may be utilized for corneal transplantation after further storage in M-K medium.

Wound healing in cultured corneal endothelial cells.

Following the application of needle, intraocular lens, freeze, and laser wounds to the center of discrete 1 cm2 areas, density-limited monolayers of cultured rabbit corneal endothelium demonstrate wound healing responses similar to those seen in in vivo corneas. The wounded monolayer reforms in a time period consistent with that seen in both in vivo and in vitro organ culture models, thus suggesting that cell motility characteristics are not dependent upon an underlying Descemet's membrane. Density-limited, cultured monolayers of corneal endothelial cells present a good model for studying the response of the endothelium to a variety of stimuli.

Chondrogenic differentiation of adipose-derived adult stem cells in agarose, alginate, and gelatin scaffolds.

The differentiation and growth of adult stem cells within engineered tissue constructs are hypothesized to be influenced by cell-biomaterial interactions. In this study, we compared the chondrogenic differentiation of human adipose-derived adult stem (hADAS) cells seeded in alginate and agarose hydrogels, and porous gelatin scaffolds (Surgifoam), as well as the functional properties of tissue engineered cartilage constructs. Chondrogenic media containing transforming growth factor beta 1 significantly increased the rates of protein and proteoglycan synthesis as well as the content of DNA, sulfated glycosaminoglycans, and hydroxyproline of engineered constructs as compared to control conditions. Furthermore, chondrogenic culture conditions resulted in 86%, and 160% increases ( p < 0.05 ) in the equilibrium compressive and shear moduli of the gelatin scaffolds, although they did not affect the mechanical properties of the hydrogels over 28 days in culture. Cells encapsulated in the hydrogels exhibited a spherical cellular morphology, while cells in the gelatin scaffolds showed a more polygonal shape; however, this difference did not appear to hinder the chondrogenic differentiation of the cells. Furthermore, the equilibrium compressive and shear moduli of the gelatin scaffolds were comparable to agarose by day 28. Our results also indicated that increases in the shear moduli were significantly associated with increases in S-GAG content ( R2 = 0.36, p < 0.05 ) and with the interaction between S-GAG and hydroxyproline ( R2 = 0.34, p < 0.05 ). The findings of this study suggest that various biomaterials support the chondrogenic differentiation of hADAS cells, and that manipulating the composition of these tissue engineered constructs may have significant effects on their mechanical properties.

Fat emulsification measured using NMR transverse relaxation.

This paper presents a novel method of measuring the droplet size in oil-in-water emulsions. It is based on changes in the NMR transverse relaxation rate due to the effect of microscopic magnetic susceptibility differences between fat droplets and the surrounding water. The longitudinal and transverse relaxation rates of a series of emulsions with constant oil volume fraction and five different mean droplet sizes, in the range 0.4-20.9 microm, were measured in vitro at 37 degrees C using EPI. While the longitudinal relaxation rate 1/T(1) did not change significantly, 1/T(2) was observed to increase with mean droplet size. The measured changes in 1/T(2) were found to be in good agreement with results predicted from proton random walk simulations, and were also consistent with analytical solutions based on an outer sphere relaxation model. Measurements of 1/T(2) on emulsions with a higher oil volume fraction, and on emulsions of a fixed size where the water phase was doped with gadolinium to modulate the susceptibility difference between the phases, also showed the predicted behavior. As part of this study the susceptibility difference between olive oil and water was measured to be 1.55 ppm.

Light element abundance in brain nuclei using energy dispersive x-ray analysis and atomic absorption spectrophotometry.

A comparative study of light element (congruent to ion) abundance in isolated brain nuclei, using atomic absorption (AA) spectrophotometry and the scanning electron microscope mode of energy dispersive x-ray analysis (EDXA), demonstrated similar statistical trends in the abundance of Na, Mg, and K at 0 time and at 4 min of total brain ischemia. The obtained correlation strengthens the validity of the comparison of quantitative and semi-quantitative procedures. The EDXA technique represents a new approach to the study of ionic shifts in brain ischemia that may prove useful in other areas of brain research as well.

Valgus laxity of the ulnar collateral ligament of the elbow in collegiate athletes.

In this investigation, we determined the patterns of valgus laxity and acquired valgus laxity of the ulnar collateral ligament in the elbows of collegiate athletes involved in overhead and nonoverhead sports. Acquired valgus laxity of the elbow is defined as the differential amount of stress valgus opening between the dominant and nondominant elbows. Forty-eight asymptomatic male athletes involved in sports that require overhead arm movements (baseball, tennis, and swimming) and 88 asymptomatic male athletes involved in nonoverhead sports (track, lacrosse, fencing, and wrestling) underwent fluoroscan examination of both their elbows with (13 daN) and without (0 N) valgus stress. There were no statistically significant differences in the amount of valgus stress opening or in acquired valgus laxity between the two groups. In fact, 25% (34 of 136) of the athletes showed an acquired valgus laxity of more than 0.5 mm, and 51.5% (70 of 136) had an acquired valgus laxity that was actually negative. There was also no correlation between the number of years played and acquired valgus laxity. Our results show that acquired valgus laxity does not exist in asymptomatic athletes involved in overhead sports, and there is no threshold value of measurement indicative of acquired valgus laxity.