The benign long term effect of cholesterol crystal synovial cysts

Summary Synovial effusions containing cholesterol crystals are uncommon. Most of the few reported cases have been found in patients with seropositive rheumatoid arthritis. In vitro studies, as well as an animal model, have suggested that cholesterol crystals could have a role in inflammation of the joints. In this report we present a case of seronegative arthritis, complicated by large carpal synovial cysts which contained numerous cholesterol crystals. The long-term presence of the cysts, without evidence of joint destruction, suggests that cholesterol crystal formation is probably a rare epiphenomenon, rather than a harbinger of inflammation.     

Molecular dynamics simulations provide molecular insights into the role of HLA‐B51 in Behçet's disease pathogenesis

Behçet's disease is an inflammatory disorder of unknown etiology. Genetic tendency has an important role in its pathogenesis, and HLA‐B51, a class I MHC antigen, has been recognized as the strongest susceptibility factor for Behçet's disease. Despite the confirmation of the association of HLA‐B51 with Behçet's disease in different populations, its pathogenic mechanisms remain elusive. HLA‐B51 differs in only two amino acids from HLA‐B52, other split antigen of HLA‐B5, which is not associated with Behçet's disease. These two amino acids are located in the B pocket of the antigen‐binding groove, which occupies the second amino acids of the bound peptides. To understand the nature of the HLA–peptide interactions, differences in structure and dynamics of two HLA alleles were investigated by molecular dynamics simulations using YAYDGKDYI, LPRSTVINI, and IPYQDLPHL peptides. For HLA‐B51, all bound peptides fluctuated to larger extent than HLA‐B52. Free energy profiles of unbinding process for YAYDGKDYI by steered molecular dynamics simulations showed that unbinding from HLA‐B52 results in greater free energy differences than HLA‐B51. These results suggest the possibility of an instability of HLA‐B51 associated with the repertoire of peptides, and this finding may provide significant insight to its pathogenic role in Behçet's disease.     

Hemostatic plug formation in normal and von Willebrand pigs: the effect of the administration of cryoprecipitate and a monoclonal antibody to Willebrand factor

Hemostatic plug (HP) formation was investigated in the ear bleeding time incision in normal and von Willebrand pigs. HP volume was calculated by integrating the areas of serial sections. In normal pigs (n = 11), platelets immediately formed a layer on the surface of the cut channel. Platelet aggregates formed at the ends of transected vessels and gradually enlarged. Finally, all transected vessels were occluded by HP and bleeding stopped. In contrast, large HPs were formed in the incision in von Willebrand's disease (vWD) pigs (n = 4); these HPs did not cover the ends of the transected vessels, which continued to bleed, allowing the formation of large hemostatically ineffective platelet aggregates in the incision. Canals traversed these HPs, and bleeding from the open vessels may have continued through them. After infusion of cryoprecipitate into a vWD pig, the bleeding time shortened, and the morphological findings of the HPs were similar to those of normal pigs. In normal pigs (n = 3) infused with an anti- Willebrand factor monoclonal antibody, which prolonged the bleeding time, a large HP formed in the incision, similar to that observed in the vWD pig. The volume of the normal and vWD HPs increased with time. These in vivo findings suggest that Willebrand factor is involved in the localization of the HP to the damaged vessel and may also play a role in platelet-platelet interaction. A computerized morphometric technique was used for measuring the volume of the hemostatic plugs and the distance of sequential points on the perimeter of the HP from the center of selected bleeding vessels.     

Low eradication rate of Helicobacter pylori with triple 7-14 days and quadriple therapy in Turkey

AIM:The eradication rate of Helicobacter pylori (H pylon) shows variation among countries and regimens of treatment.We aimed to study the eradication rates of different regimens in our region and some factors affecting the rate of eradication.METHODS:One hundred and sixty-four Hpylori positivepatients (68 males, 96 females; mean age:48±12 years)with duodenal or gastric ulcer without a smoking history were included in the study. The patients were divided into three groups according to the treatment regimens. Omeprazole 20mg, clarithromycin 500mg, amoxicillin 1g were given twice daily for 1 week (Group I) and 2 weeks (Group Ⅱ).Patients in Group Ⅲ received bismuth subsitrate 300mg,tetracyline 500 mg and metronidazole 500mg four times daily in addition to Omeprazole 20mg twice daily.Two biopsies each before and after treatment were obtained from antrum and corpus, and histopathologically evaluated.Eradication was assumed to be successful if no Hpylorus was detected from four biopsy specimens taken after treatment. The effects of factors like age, sex, Hpyloridensity on antrum and corpus before treatment, the total Hpylori density, and the inflammation scores on the rate of Hpylori eradication were evaluated.RESULTS:The overall eradication rate was 42%. The rates in groups Ⅱ and Ⅲ were statistically higher than that in group I (P<0.05). The rates of eradication were 24.5%,40.7% and 61.5% in groups Ⅰ, Ⅱ and Ⅲ, respectively. The eradication rate was negatively related to either corpus Hpylori density or total Hpyloridensity (P<0.05).The median age was older in the group in which the eradication failed in comparison to that with successful eradication (55yr vs 39yr, P<0.001). No correlation between sex and Hpylori eradication was found.CONCLUSION: Our rates of eradication were significantly lower when compared to those reported in literature.We believe that advanced age and high Hpyloridensity are negative predictive factors for the rate of Hpylorieradication.     

A novel approach to improve undergraduate surgical teaching

Background:

Undergraduate surgery is at an important crossroads. Many departments report significant difficulties delivering effective teaching. Our student feedback indicated a dated surgical curriculum lacking structure, quality and uniformity. We report on a new ”blended” approach employing a combination of professional DVDs, case based discussions, online material and traditional bedside teaching designed to provide structure, standardization, and equality of learning .

Methods:

Year 4 students who had undertaken the new course and year 5 students who had participated in the traditional teaching programme were compared. Students completed a 20 item questionnaire about their experiences of the surgical teaching programme.

Results:

One hundred and seventy-one year 4 (70%) and148 year 5 students (66%) responded. Domains relating to “Overall Satisfaction with the course”, “Approval of innovative teaching methods and interactivity” and “Satisfaction with the clarity of course information” showed improvements when comparing the new and old programmes. However bedside teaching was not rated as highly in the new programme (p<0.05).

Conclusion:

This blended approach has resulted in improved student understanding and engagement. The apparent compromise of bedside teaching may be a reflection of higher expectations. We believe that a similar blended approach has the potential to re-invigorate surgical teaching elsewhere.     

Helicobacter pylori eradication lowers serum homocysteine level in patients without gastric atrophy

AIM: To determine whether Helicobacter pylori (H pylori) infection caused hyperhomocysteinemia by altering serum vitamin B_(12), serum folate and erythrocyte folate levels and whether eradication of this organism decreased serum homocysteine level. METHODS: The study involved 73 dyspeptic H pylork positive patients, none of them had gastric mucosal atrophy based on rapid urease test and histology. Out of 73 patients, 41 (56.2%) showed a successful eradication of H pylori 4 wk after the end of treatment. In these 41 patients, fasting serum vitamin B_(12) folate and homocysteine levels, and erythrocyte folate levels before and 4 wk after H pylori eradication therapy were compared. RESULTS: The group with a successful eradication of H pylori had significantly higher serum vitamin B_(12) and erythrocyte folate levels in the post-treatment period compared to those in pre-treatment period (210±97 pg/mL vs 237±94 pg/mL,P＜0.001 and 442±212 ng/mL vs 539±304 ng/mL, P=0.024, respectively), but showed no significant change in serum folate levels (5.6±2.6 ng/mL vs 6.0+2.4 ng/mL, P=0.341). Also, the serum homocysteine levels in this group were significantly lower after therapy (13.1±5.2 μmol/L vs 11.9±6.2 μmol/L, P=0.002). Regression analysis showed that serum homocysteine level was positively correlated with age (P=0.01) and negatively with serum folate level before therapy (P=0.003). CONCLUSION: Eradication of H pylori decreases serum homocysteine even in patients who do not exhibit gastric mucosal atrophy. It appears that the level of homocysteine in serum is related to a complex interaction among serum vitamin B_(12), serum folate and erythrocyte folate levels.