Isolation and Properties of a Macromolecular, Water-Soluble, Immuno-Adjuvant Fraction from the Cell Wall of Mycobacterium smegmatis

Trypsin- and chymotrypsin-treated delipidated cell walls of Mycobacterium smegmatis were digested overnight with lysozyme. The water-soluble products thus obtained were filtered on a column of Sephadex G-50; the first peak, excluded from the column, has immunological adjuvant activity. The material of the excluded peak is obtained after lyophilization as a snow-white, fluffy material, soluble in water and insoluble in organic solvents. It behaves as a slightly polydisperse macromolecule in an ultracentrifuge, with an approximate molecular weight of 20,000. All the constituents of this material are typical bacterial cell-wall constituents; thus, the water-soluble adjuvant is considered to be an "oligomer" of the cell wall.When added to Freund's incomplete adjuvant with an antigen (e.g., ovalbumin) and injected into hind-foot pads of guinea pigs, this water-soluble adjuvant increases the amount of precipitating antibodies and induces hypersensitivity to ovalbumin and the biosynthesis of gamma(2)-type precipitating antibodies. The water-soluble material has a stronger adjuvant activity than equal amounts of whole bacteria, cell walls, or wax D, and seems to be the first well-defined, water-soluble, adjuvant-active fraction isolated from Mycobacteria.     

Eating the enemy in Crohn's disease: An old theory revisited

Several old and new observations suggest the existence in Crohn's disease of a phagocytic disorder of macrophages related to impaired bactericidal activity of host cells or to the presence of invasive bacteria that have developed strategies to counteract macrophage killing. It was recently reported that disordered macrophage cytokine secretion underlies impaired acute inflammation and bacterial clearance in Crohn's disease. Secretion of proinflammatory cytokines by CD macrophages was impaired in response to E. coli or specific Toll-like receptor agonists. In addition, major advances in the etiology of Crohn's disease came from the existence of polymorphism in NOD2 and autophagy-related susceptibility genes (ATG16L1 and IRGM) in patients and from the identification of the presence of adherent-invasive E. coli (AIEC) colonizing the CD ileal mucosa and able to resist to macrophage killing. The role of impaired autophagy in Crohn's disease patients has been recently reinforced by the observation that the peptidoglycan receptor NOD2, in addition to sense intracellular bacteria, can induce autophagy by recruiting the critical autophagy protein ATG16L1 to the plasma membrane during bacterial internalization. Defects in autophagy might be the key element of the pathogenic pathway that lead to defective microbial killing, increased exposure to commensal and pathogenic intestinal bacteria and T cell activation. Defects in Paneth cells secreting lysozyme and antimicrobial peptides are observed in patients with ATG16L1 risk allele. Thus, the induction of autophagy or administration of preparations that mirrors the secretion of Paneth cells or both may be regarded as new therapeutic avenues for the treatment of Crohn's disease.     

Drinking Against Unpleasant Emotions: Possible Outcome of Early Onset of Alcohol Use?

Background: Recent animal and human studies indicate that the exposure to alcohol during early adolescence increases the risk for heavy alcohol use in response to stress. The purpose of this study was to examine whether this effect may be the consequence of a higher susceptibility to develop “drinking to cope” motives among early initiators. Methods: Data from 320 participants were collected as part of the Mannheim Study of Children at Risk, an ongoing epidemiological cohort study. Structured interviews at age 15 and 19 were used to assess age at first alcohol experience and drunkenness. The young adults completed questionnaires to obtain information about the occurrence of stressful life events during the past 4 years and current drinking habits. In addition, alcohol use under conditions of negative states was assessed with the Inventory of Drinking Situations. Results: The probability of young adults’ alcohol use in situations characterized by unpleasant emotions was significantly increased the earlier they had initiated the use of alcohol, even when controlling for current drinking habits and stressful life events. Similar results were obtained for the age at first drunkenness. Conclusions: The findings strengthen the hypothesis that alcohol experiences during early adolescence facilitate drinking to regulate negative affect as an adverse coping strategy which may represent the starting point of a vicious circle comprising drinking to relieve stress and increased stress as a consequence of drinking.     

High prevalence of adherent-invasive Escherichia coli associated with ileal mucosa in Crohn's disease

BACKGROUND & AIMS: Adherent-invasive Escherichia coli (AIEC) pathovar has been identified in the intestinal mucosa of patients with Crohn's disease (CD). AIEC reference strain LF82 is able to adhere to intestinal epithelial cells, to invade epithelial cells via a mechanism involving actin polymerization and microtubules, and to survive and replicate within macrophages. This study was performed to assess the prevalence of AIEC associated with intestinal mucosa of patients with CD, ulcerative colitis (UC), and of controls. METHODS: A search for E. coli strains was performed with ileal specimens of 63 patients with CD and 16 controls without inflammatory bowel disease (IBD), and with colonic specimens of 27 patients with CD, 8 patients with UC, and 102 controls. The abilities of E. coli strains to invade epithelial cells and to survive and replicate within macrophages were assessed using the gentamicin protection assay. Bacterial uptake by epithelial cells was analyzed using cytoskeletal inhibitors. Bacterial adhesion was quantified with Caco-2 and Intestine-407 cells. The presence of known E. coli virulence genes was assessed by polymerase chain reaction and DNA hybridization. RESULTS: In ileal specimens, AIEC strains were found in 21.7% of CD chronic lesions vs. in 6.2% of controls. In neoterminal ileal specimens, AIEC strains were found in 36.4% of CD early lesions (P = 0.034 vs. controls) and 22.2% of healthy mucosa of CD patients. In colonic specimens, AIEC strains were found in 3.7% of CD patients, 0% of UC patients, and 1.9% of controls. CONCLUSIONS: AIEC strains are associated specifically with ileal mucosa in CD.     

Disseminated arterial occlusions revealing bilateral venous thrombosis with paradoxical embolisms

Paradoxical embolism is a diagnosis of exclusion. Clinical triad associates deep venous thrombosis with or without pulmonary embolism, arterial embolism, and intracardiac communication with right-to-left shunt. The intracardiac communication is generally related to a patent foramen ovale (PFO). We report a 75-year-old patient, who presented with bilateral deep venous thrombosis of the legs, complicated by massive pulmonary embolism and paradoxical embolisms through a PFO. This resulted in cerebral, mesenteric, splenic and bilateral kidney infarctions. A promptly initiated anticoagulant treatment allowed a favourable outcome.     

Methionine-induced elevation of plasma homocysteine concentration is associated with an increase of plasma cholesterol in adult rats

BACKGROUND AND AIMS: Dietary methionine affects cholesterol metabolism in growing rats. Methionine effects on adult rats and mechanisms by which methionine alters the lipid metabolism are not fully elucidated. We investigated possible mechanisms by which dietary methionine acts on lipid metabolism of adult rats. METHODS: Male adult rats were divided into three groups (n=10) and were fed casein-based diets differing in methionine concentration (low-methionine diet: 0.96 g/kg; adequate-methionine diet: 2.22 g/kg, high-methionine diet: 6.82 g/kg) for 4 weeks. Concentrations of triacylglycerols and cholesterol in plasma and lipoproteins, concentration of homocysteine in plasma, concentration of cholesterol in liver, fecal lipid excretion, expression of hepatic HMG-CoA reductase, phosphatidylethanolamine N-methyltransferase 2 (PEMT-2) and of LDL receptor were measured. RESULTS: Rats fed the high-methionine diet had higher plasma homocysteine concentrations than rats fed the low-methionine diet (p<0.05). Although concentrations of cholesterol in plasma and lipoproteins were not different between the groups, there was a distinct positive correlation between circulating plasma homocysteine and plasma cholesterol (R(2)=0.55, p<0.001). The fecal excretion of cholesterol and bile acids was not altered by dietary methionine. The relative mRNA concentration of HMG-CoA reductase and of LDL receptor remained unaffected by dietary methionine. Gene expression of PEMT-2 was higher in rats fed the high-methionine diet than in rats fed the other diets (p<0.05). CONCLUSION: The results demonstrate that dietary methionine contributes to a rise in circulating homocysteine concentration which positively correlates with the concentration of plasma cholesterol. However, the effects of methionine on cholesterol metabolism of adult rats were relatively weak.     

Evaluation of EMIT-TOX Enzyme Immunoassay for the analysis of benzodiazepines in serum: usefulness and limitations in an emergency laboratory

The EMIT-TOX Enzyme Immunoassay for benzodiazepines was evaluated. Reproducibility, linearity, accuracy, sensitivity, and interferences were tested and found to be in good agreement with the manufacturer's specifications. Furthermore, the reactivity of 15 benzodiazepines were studied. According their differential reactivity, the 15 benzodiazepines can be classified into three groups: good reactivity similar to diazepam (potassium clorazepate, prazepam, estazolam, medazepam, flunitrazepam, nitrazepam); medium reactivity (clobazam, clonazepam, bromazepam, chlordiazepoxide, triazolam); and low reactivity (oxazepam, ethyl loflazepate, lorazepam). A possible structure/reactivity relationship is discussed. It is concluded that this kit is well adapted for the rapid detection of most benzodiazepines, but in no way can the EMIT technique permit quantitative results without clinical information.     

Effect of self-etching adhesives on dentin permeability in a fluid flow model

STATEMENT OF PROBLEM: Numerous self-etching bonding systems exist, with composition differing from one product to another. It is important for the clinician to know if they are all equally effective, and whether they provide an effective seal between dentin and restorative materials. PURPOSE: This study was designed to measure the hydraulic conductance of physiologic saline across dentin after application of various self-etching bonding systems or of a 1-bottle adhesive system preceded by a phosphoric acid etch. MATERIAL AND METHODS: One hundred extracted noncarious human third molars from patients 18-25 years old were used for this study. Dentin disks were cut from crown segments parallel to the occlusal surface at the top of the pulp cavity. The 100 disks, each 1 mm thick, were divided into 10 groups (n=10 per group), each of which was treated with 1 of 9 self-etching systems-AdheSE, Adper Prompt L-Pop, Clearfil SE Bond, Etch & Prime 3.0, Prime & Bond NRC Nt, One-Up Bond F, optiBond solo Plus Self Etch, Prompt L-Pop, or Xeno III-or a control bonding system (Prime & Bond NT) preceded by a phosphoric acid etch. Hydraulic conductance, the volume of fluid transported across a known area of surface (0.28 cm2) per unit time under a unit pressure gradient (200 cm H2O), was analyzed for the adhesive systems using a fluid flow apparatus (Flodec). First, both sides of each specimen were etched with 36% phosphoric acid for 30 seconds, and the hydraulic conductance was measured every 30 seconds for 15 minutes. The initial set of measurements served as the reference value for each specimen. The measurements were repeated when a smear layer had been formed and, finally, after 1 of the 10 bonding systems had been applied. The data were analyzed using a 1-way ANOVA and Duncan's multiple range test (alpha=.05). RESULTS: The control 1-bottle adhesive used with a phosphoric acid pre-etch did not provide the largest reduction in penetration (42.3%). The greatest mean reduction (68.9%, P<.05) was observed with the self-etching product Xeno III. The mean reduction for the other materials tested were: One-Up Bond F, 60.5%; AdheSE, 58.2%; Etch & Prime 3.0, 56.8%; Adper Prompt L-Pop, 51%; optiBond solo Plus Self Etch, 45%; Clearfil SE Bond, 35.5%, Prime & Bond NRC Nt, 16.4%; and Prompt L-Pop, 16.3%. CONCLUSION: Within the limitations of this study, the self-etching systems tested produced different reductions in dentin permeability. For some, the reduction was much greater than the decrease in dentin permeability provided by the bonding system with a phosphoric acid pre-etch; for others, the reduction was small.     

Photodynamic therapy for Barretts’ adenocarcinoma associated with an Angelchik device

We present a novel case of an elderly patient with a Barrett's adenocarcinoma in the presence of an Angelchik prosthesis. We aim to draw attention to issues relating to metaplastic Barretts’ oesphagus and its adenocarcinoma complications and highlight relevant issues in multimodal endoscopic management and palliation using photodynamic therapy in the presence of the device.