Simulated training in colonoscopic stenting of colonic strictures: validation of a cadaver model.

AIM: There are currently no available simulation models for training in colonoscopic stent deployment. The aim of this study was to validate a cadaver model for simulation training in colonoscopy with stent deployment for colonic strictures. METHOD: This was a prospective study enrolling surgeons at a single institution. Participants performed colonoscopic stenting on a cadaver model. Their performance was assessed by two independent observers. Measurements were performed for quantitative analysis (time to identify stenosis, time for deployment, accuracy) and a weighted score was devised for assessment. The Mann-Whitney U-test and Student's t-test were used for nonparametric and parametric data, respectively. Cohen's kappa coefficient was used for reliability. RESULTS: Twenty participants performed a colonoscopy with deployment of a self-expandable metallic stent in two cadavers (groups A and B) with 20 strictures overall. The median time was 206 s. The model was able to differentiate between experts and novices (P = 0. 013). The results showed a good consensus estimate of reliability, with kappa = 0.571 (P < 0.0001). CONCLUSION: The cadaver model described in this study has content, construct and concurrent validity for simulation training in colonoscopic deployment of self-expandable stents for colonic strictures. Further studies are needed to evaluate the predictive validity of this model in terms of skill transfer to clinical practice.

Association of a polymorphism in the indoleamine- 2,3-dioxygenase gene and interferon-α-induced depression in patients with chronic hepatitis C.

Interferon (IFN)-α treatment for infectious diseases and cancer is associated with significant depressive symptoms that can limit therapeutic efficacy. Multiple mechanisms have been implicated in IFN-α-induced depression including immune, neuroendocrine and neurotransmitter pathways. To further explore mechanisms of IFN-α-induced depression and establish associated genetic risk factors, single nucleotide polymorphisms in genes encoding proteins previously implicated in IFN-α-induced depression were explored in two self-reported ethnic groups, Caucasians (n=800) and African Americans (n=232), participating in a clinical trial on the impact of three pegylated IFN-α treatment regimens on sustained viral response in patients with chronic hepatitis C. Before treatment, all subjects were free of psychotropic medications and had a score ≤20 on the Center for Epidemiologic Studies Depression Scale (CES-D), which was used to assess depressive symptom severity throughout the study. In Caucasians, a polymorphism (rs9657182) in the promoter region of the gene encoding indoleamine-2,3-dioxygenase (IDO1) was found to be associated with moderate or severe IFN-α-induced depressive symptoms (CES-D>20) at 12 weeks of IFN-α treatment (P=0.0012, P<0.05 corrected). Similar results were obtained for treatment weeks 24, 36 and 48. In subjects homozygous for the risk allele (CC, n=150), the odds ratio for developing moderate or severe depressive symptoms at treatment week 12 was 2.91 (confidence interval: 1.48-5.73) compared with TT homozygotes (n=270). rs9657182 did not predict depression in African Americans, who exhibited a markedly lower frequency of the risk allele at this locus. The findings in Caucasians further support the notion that IDO has an important role in cytokine-induced behavioral changes.

Nine genes abundantly expressed in the epididymis are not essential for male fecundity in mice.

BACKGROUND: Spermatozoa become competent for fertilization during transit through the epididymis. As spermatozoa from the proximal caudal epididymis can fertilize eggs, proteins from the caput and corpus epididymis are required for sperm maturation. OBJECTIVES: Microarray analysis identified that more than 17,000 genes are expressed in the epididymis; however, few of these genes demonstrate expression restricted to the epididymis. To analyze epididymis-enriched gene function in vivo, we generated knockout (KO) mutations in nine genes that are abundantly expressed in the caput and corpus region of the epididymis. MATERIALS AND METHODS: KO mice were generated using the CRISPR/Cas9 system. The histology of the epididymis was observed with hematoxylin and eosin staining. KO males were caged with wild-type females for 3-6 months to check fertility. RESULTS: We generated individual mutant mouse lines having indel mutations in Pate1, Pate2, or Pate3. We also deleted the coding regions of Clpsl2, Epp13, and Rnase13, independently. Finally, the 150 kb region encoding Gm1110, Glb1l2, and Glb1l3 was deleted to generate a triple KO mouse line. Histology of the epididymis and sperm morphology of all KO lines were comparable to control males. The females mated with these KO males delivered pups at comparable numbers as control males. DISCUSSION AND CONCLUSION: We revealed that nine genes abundantly expressed in the caput and corpus epididymis are dispensable for sperm function and male fecundity. CRISPR/Cas9-mediated KO mice generation accelerates the screening of epididymis-enriched genes for potential functions in reproduction.

Regional, socioeconomic and behavioural- impacts on consumer acceptability of beef in Northern Ireland, Republic of Ireland and Great Britain.

This study was commissioned to assess if there are regional differences in the acceptability of beef between consumers from Northern Ireland (NI), Republic of Ireland (ROI) and Great Britain (GB). Palatability traits were affected by socioeconomic and behavioural factors such as preferred cooking endpoint, animal welfare, value, health aspects of beef product, ease of preparation as well as consumption frequency for specific cuts. "Willingness to pay" (WTP) was influenced by income, preferred cooking endpoint, value of beef product, ease of preparation and consumption frequency for frying steak. Results showed that GB consumers scored higher for the same striploin steak compared to NI and ROI consumers. This may be due to differences in the motivation for beef choice and/or consumption habits. GB consumers were less concerned about the healthiness of beef product and beef origin. In addition, a higher consumption frequency for rump was reported in GB, which may explain the higher sensory scores observed among GB consumers for striploins.

The effect of amino acids and dipeptides on sodium-ion transport in rat enterocytes.

Sodium efflux from isolated intestinal epithelial cells was measured during incubation with several different free amino acids and dipeptides. L-Leucine, which is cotransported with sodium across the brush border membrane, significantly stimulated the total sodium efflux and almost all of this increase involved the ouabain-sensitive flux, i.e., the active component. In contrast, glycyl-L-leucine had little or no effect on active sodium efflux either in the presence or absence of 0.1 mM bestatin, a peptide hydrolase inhibitor. A second dipeptide L-carnosine (beta-alanyl-L-histidine) which is poorly hydrolysed by enterocytes also had no effect upon sodium efflux. However, glycylglycine, which has been shown to be cotransported with sodium, did stimulate the ionic efflux. In addition, measurement of sodium uptake by sheets of small intestine showed that glycyl-L-leucine, carnosine and glycyl-L-proline failed to increase the uptake of the ion, while glycylglycine did significantly stimulate sodium uptake. These data indicate that some dipeptides are not cotransported with sodium, while others are. This suggests that there may well be multiple peptide transporters with very different characteristics in the brush border membrane of enterocytes.

Identification of sensory attributes, instrumental and chemical measurements important for consumer acceptability of grilled lamb Longissimus lumborum.

In this study, important eating quality attributes that influence consumer liking for grilled lamb loin have been identified using preference mapping techniques. The eating quality attributes identified as driving the consumer liking of lamb loin steaks were "tenderness", "sweet flavour", "meaty aftertaste", "roast lamb flavour" and "roast lamb aftertaste". In contrast, the texture attribute "rubbery" and the flavour attributes "bitter flavour" and "bitter aftertaste" had a negative influence on consumer perceptions. Associations were observed between eating quality and a number of instrumental and chemical measurements. Warner Bratzler Shear Force showed an association with "rubbery" texture and a negative association with "tenderness" and consumer liking scores. The compounds, glucose, glucose-6-phosphate, inosine, inosine monophosphate and adenosine monophosphate were associated with the attributes, "sweet flavour","meaty aftertaste", "roast lamb flavour", "roast lamb aftertaste" and with consumer scores for liking of lamb which is probably caused by the role some of these compounds play as precursors of flavour and as taste compounds.

Heterogeneity in restriction patterns of Gardnerella vaginalis isolates from individuals with bacterial vaginosis.

This study was undertaken to resolve the genetic make up of Gardnerella vaginalis present in bacterial vaginosis (BV). DNA from several G. vaginalis isolates from within and between individual BV patients were compared by BamHI, ClaI and EcoRI restriction endonuclease analysis (REA) followed by a restriction fragment length polymorphism (RFLP) study, utilizing a 5.7-kb BamHI G. vaginalis ATCC14018 DNA probe. Four G. vaginalis isolates from one patient (GVP-062) were composed of 3 different biotypes (biotypes 3, 5 and 8), and while the REA mirrored the biotype, in RFLP studies at least 3 isolates had DNA fragments in common. All of the isolates from 2 other patients (GVP-063 and GVP-072) represented a single biotype (biotype 2), but under REA and in RFLP studies, the isolates GVP-063 differed from GVP-072. An opposite case existed with the isolates GVP-072 (biotype 2) and GVP-065 (biotype 5), which appeared similar under REA and in RFLP studies. Finally, reisolates after 8 weeks (GVP-080) from a BV patient (isolates GVP-065) representing the same biotype (biotype 5) differed under REA and in RFLP studies. Thus, lacking any unique DNA fingerprint, G. vaginalis occurring in BV represents a (genetically) mixed population.

The characterization of Gardnerella vaginalis DNA using non-radioactive DNA probes.

DNA restriction profiles of various Gardnerella vaginalis isolates, generated by BamHI, EcoRI, PstI and other restriction enzymes, varied considerably. Only a few DNA fragments were identified as common in ethidium bromide fluorescence profile and Southern-blot hybridization patterns (employing a digoxigenin-labelled G. vaginalis DNA probe and an enzyme-linked immunoassay detection method). While the efficiencies of Southern-blot hybridization appeared inconsistent, in dot-blot assays, DNA from each isolate hybridized readily, enabling the detection of at least 10 ng DNA. A 5.7-kb DNA fragment from G. vaginalis ATCC 14018 genomic library, cloned in the BamHI site of pBR322, could replace the total genomic DNA probe. This specific DNA fragment was present in different sizes in 12 analysed G. vaginalis strains, describing a restriction fragment length polymorphism. In control studies, none of the DNA from bacteria other than G. vaginalis (including some genitourinary tract residents) hybridized with the G. vaginalis total or specific DNA probes. Non-radioactive G. vaginalis DNA probes can thus form the basis of a useful detection method for further studies of this organism.

A comparative cytologic study of 100 urine specimens processed by the slide centrifuge and membrane filter techniques.

An evaluation of cytology preparations made by the slide centrifuge and membrane filter techniques was made on 100 consecutive urine specimens from 46 patients. The membrane filter technique gave better cellular recovery and produced slides qualitatively superior to those prepared by the slide centrifuge technique. The former, therefore, is the recommended method. The slide centrifuge might be of greater value with urine of low cellularity where the membrane filter has provided only a few to practically no cells. The diagnostic accuracy on clinical follow-up of the patients included in this study is 94% for both methods, with no false positive cases and a 6% false negative rate. This high degree of accuracy indicates that these concentrating methods may lead to clinically valuable information if used routinely in the cytology laboratory.

A historical review of dental and facial skeletal trauma.

It is only in the past 100 years that dentists have embraced the concept of occlusion as the guide for reducing and stabilizing fractures involving the jaws. Through early history and into the middle ages, there were two schools of thought regarding the management of jaw fractures. Often overlooked is the influence wars have had on the evolution of treatment of maxillofacial injuries.

The effect of acid pretreatment on the anaerobic digestion and dewatering of waste activated sludge.

Waste activated sludge (WAS) is difficult to degrade in anaerobic digestion systems and pretreatments have been shown to speed up the hydrolysis stage. Here the effects of acid pretreatment (pH 6-1) using HCl on subsequent digestion and dewatering of WAS have been investigated. Optimisation of acid dosing was performed considering digestibility benefits and level of acid required. Pretreatment to pH 2 was concluded to be the most effective. In batch digestion this yielded the same biogas after 13 days as compared to untreated WAS at 21 days digestion. In semi-continuous digestion experiments (12 day hydraulic retention time at 35°C) it resulted in a 14.3% increase in methane yield compared to untreated WAS, also Salmonella was eradicated in the digestate. Dewatering investigations suggested that the acid pretreated WAS required 40% less cationic polymer addition to achieve the same cake solid content. A cost analysis was also carried out.

Performance parameter prediction for sewage sludge digesters using reflectance FT-NIR spectroscopy.

This study investigates the use of Fourier transform near infrared (FT-NIR) spectroscopy combined with principle components analysis (PCA) and partial least squares regression (PLS-R) as part of a possible process monitoring system for sewage sludge anaerobic digesters. The ability of FT-NIR with PCA to distinguish between different stages of the AD process was investigated, it was found that waste activated sludge (WAS), primary, feed (Primary:WAS 70:30) and digested sludge were distinguishable from each other using this technique. PLS-R was used successfully to track differing proportions of primary:WAS in feedstocks of 5% total solids (Coefficient of Efficiency (CE) = 0.93). The study also looked at the ability of reflectance mode NIR spectroscopy to track process parameters important for stability. Temperature and organic loading rate variations were employed to stress the digesters. Predictive models were produced for volatile fatty acids (VFA), bicarbonate alkalinity (BA) and total and volatile solids (TS and VS) and independently validated for each digester. The models were able to track the relevant process parameters: TS (CE = 0.75), VS (CE = 0.75), BA (CE = 0.71), and VFA (CE = 0.69). This technique could be used to improve the performance of sewage sludge anaerobic digesters.

Cyanide metabolism in the isolated, perfused, bloodless hindlimbs or liver of the rat.

Female CD1 rats weighing 250-300 g were anesthetized with ip pentobarbital, 50 mg/kg, and either the liver or the hindlimbs were surgically isolated and perfused in situ with a Krebs-Henseleit buffer, pH 7.4, at 38 degrees C, containing 40 g/liter dextran and 30 mg/liter papaverine. Perfusion pressure was continuously monitored, and in most experiments, flow was maintained at the physiological rate of 8.5 ml/min. In-line Clark-type electrodes allowed the continuous measurement of oxygen extraction. Potassium cyanide to 0.15 mM was usually added to the perfusate just prior to the start of a run. After a period of equilibration, samples of the perfusate were taken periodically for cyanide (CN) and thiocyanate (SCN) analyses. The results were used to determine CN extraction ratios or clearance and rates of SCN formation. When it was apparent that a steady state had been reached with respect to the above, sodium thiosulfate (TS) was added to the perfusate (to 0.1, 1.0, or 2.0 mM), and periodic samples were again collected after an equilibration period. In the absence of albumin, TS rapidly and significantly increased the rate of conversion of CN to SCN in both the liver and the hindlimbs. The rate of CN clearance in milliliters per minute per kilogram perfused tissue was 20-fold greater in the liver than in the hindlimbs. However, when the results from hindlimbs were extrapolated to the total body skeletal muscle mass, the rate of CN clearance by the total liver mass was only 1.5-fold greater than in total muscle mass. In the absence of TS, total muscle mass cleared CN at a rate that was 2.6-fold greater than the total liver mass, but the rates in both tissues were very much less than in the presence of TS. The extraction ratio for CN in the liver was 0.8 and the clearance was dependent on the flow rate. The extraction ratio for CN in the hindlimbs was 0.2, and the clearance was independent of the flow rate. Thus, CN clearance by the liver probably increases (within limits) with increasing portal blood flow. Evidence was obtained for the existence of a significant CN "sink," particularly in the liver, which presumably represents reversible binding to unknown tissue constituents.

Cyanide release from nitroprusside in the isolated, perfused, bloodless liver and hindlimbs of the rat.

When sodium nitroprusside in artificial medium was perfused through the isolated liver and hindlimbs of a rat at the near physiological flow rate of 8.5 ml min-1, free cyanide was found in the perfusate. The liver reached a steady-state ratio of cyanide released/nitroprusside perfused of about 1.5 (or approximately 30% of the total nitroprusside cyanide) within 15 min, and maintained that rate for about 1.5 hr. In the hindlimbs cyanide was released at a much slower rate (7.5 to 18.8% of the total), and the release did not achieve a steady state even after 1.5 hr. Even after small corrections for cyanide extraction by both tissues, the rate of cyanide release by either tissue was probably more rapid than that resulting from static incubations in blood.

Evaluation of skin sensitization response of dialkyl (C6-C13) phthalate esters.

Isolated case reports suggest that dermal contact with some phthalate esters may result in skin sensitization. This issue was investigated in guinea pig sensitization tests, but the results were inconclusive. Consequently, 7 dialkyl phthalate esters, (diisohexyl, diisoheptyl, di(2-ethylhexyl), diisononyl, diisodecyl, diundecyl and ditridecyl phthalates), ranging in carbon number from C6 to C13, were tested in a 104-person panel human repeated insult patch test (HRIPT) using the modified Draize procedure. Test concentrations of 100% were selected for the induction and challenge phases of the HRIPT based upon a 24-h occluded irritation test on 15 panelists. Under the conditions of this HRIPT, no evidence of dermal irritation or sensitization for any of the 7 phthalate esters was observed in the 104-person panel. These HRIPT data provide evidence for the lack of experimental skin sensitization potential for the phthalate esters tested.

Histochemical localization of rhodanese activity in rat liver and skeletal muscle.

A previously described histochemical technique was applied to the localization of rhodanese (thiosulfate sulfurtransferase, EC 2.8.1.1) activity in rat skeletal muscle and liver. The physiological function of rhodanese is controversial, but it and other sulfurtransferases can catalyze the conversion of cyanide to the much less toxic thiocyanate. The volume of distribution of cyanide in human and dog is said to correspond roughly to the blood volume. Because of this and other observations, it was hypothesized that sulfurtransferase activity associated with the vascular endothelium on smooth muscle layers of blood vessels might play a role in cyanide detoxification. However, little enzyme activity as identified histochemically was associated with those sites in comparison with others examined. As expected, high activity was found in the liver and moderately high levels were present in skeletal muscle. In muscles sectioned longitudinally, points of rhodanese staining occurred in linear arrays along the lengths of the muscle fiber corresponding to the location of mitochondria within the fiber. The original technique called for incubation of tissue sections with both thiosulfate and cyanide. When thiosulfate was omitted, staining for rhodanese activity was still clearly identifiable in both liver and muscle sections with cyanide alone. In muscle sections the inclusion of both thiosulfate and cyanide resulted in a preferential staining of type I fibers presumably because of their higher content of mitochondria. Thus, this technique is a potential alternative to the NADH dehydrogenase stain for distinguishing between type I and type II muscle fibers. Incubation of tissue sections with only thiosulfate produced results that did not appear to differ from those obtained when both substrates were omitted. From these observations it may be inferred that the endogenous pool of sulfane-sulfur available to sulfurtransferases is larger than any alleged endogenous pool of cyanide. Although sulfurtransferase activity in muscle appeared to be lower than that in liver, the total body muscle mass is greater than the liver mass. Thus, these results support other evidence that skeletal muscle may make a significant contribution to total cyanide biotransformation in the absence of exogenously added thiosulfate.

Repeated immobilization stress increases the binding of c-Fos-like proteins to a rat dopamine beta-hydroxylase promoter enhancer sequence.

Repeated immobilization stress elicits a large elevation in adrenal dopamine beta-hydroxylase (DBH) mRNA levels. This study attempts to analyze the molecular mechanism of increased DBH gene expression in stress. Adrenomedullary nuclear proteins were prepared from controls and rats exposed to various intervals of immobilization stress. Electrophoretic mobility shift assays showed that repeated stress led to increased binding of adrenomedullary nuclear factors to a cis-acting regulatory element in the rat DBH promoter (DBH-1). One of the partners in the DNA-protein complex is c-Fos or a Fos-related protein. There was a correlation between promoter binding activity and elevated steady-state levels of DBH mRNA. Our data indicate that this cis regulatory element in the rat DBH promoter is functional in vivo, and increased binding of AP1-like transcription factors to this motif is induced by immobilization stress.