HLA-D and -DR antigens in genetic analysis of insulin dependent diabetes mellitus

Summary Three groups of patients with insulin-dependent diabetes mellitus, ascertained by different procedures, were investigated for HLA-A, B, C and D antigens (n=164), and a subset (n=93) for HLA-DR. Both HLA-D/DR3 and D/DR4 were strongly positively associated and D/DR2 was negatively associated with insulin-dependent diabetes. HLA-DR4 was found to be a better marker for insulin-dependent diabetes than Dw4. The HLA-B associations (B8, B15 and B18) were clearly secondary to the increases of HLA-D/DR3 and D/DR 4. The HLA associations did not differ between familial and isolated cases indicating that these two groups may well have a common genetic background. Based on analysis of HLA-haplotype sharing in affected sibling pairs, a simple dominant model of inheritance could be ruled out, and a simple recessive model was found unlikely. The relative risks for the HLA-Dw3,4 and HLA-DR3,4 phenotype were 21.2 and 44.4 respectively and exceeded those of both the HLA-Dw3 and HLA-DR3 (5.6 and 4.3) as well as the HLA-Dw4 and DR4 (10.1 and 10.5) phenotypes. This argues against an intermediate genetic model but further studies are needed to clarify whether there is more than one susceptibility gene for insulin-dependent diabetes mellitus within the HLA-system. Note. A list with detailed data on all patients is available from the authors on request.     

Intraoperative assessment of esophagogastric junction distensibility during per oral endoscopic myotomy (POEM) for esophageal motility disorders

Background

Per oral endoscopic myotomy (POEM) is a novel treatment for esophageal motility disorders such as achalasia. To date, the extent of the myotomy has been determined based on the subjective assessment of the endoscopist. We hypothesized that the real-time measurement of esophagogastric junction (EGJ) distensibility using a novel functional lumen-imaging probe would enable objective evaluation of POEM.

Methods

Patients diagnosed with achalasia disorders electively underwent POEM. Using impedance planimetry with a transorally inserted functional lumen-imaging probe (EndoFLIP^®), cross-sectional areas (CSA) and distensibilities at the EGJ were measured intraoperatively immediately before and after the transoral myotomy (n = 4). All patients completed their 6-month follow-up and two patients had repeat distensibility tests at this time. Four healthy volunteers served as a control group.

Results

POEM was successfully performed in all patients (4/4). Premyotomy measurements (40-ml fill mode) showed a median diameter of 6.5 mm (range = 5.2–7.9 mm) at the narrowest location of the EGJ and was 10.1 mm (7.3–13.2 mm) following POEM. CSA increased from 41.5 mm² (20–49 mm²) to 86 mm² (41–137 mm²) at a similar median intraballoon pressure (40.3 vs. 38.6 mmHg). The increased EGJ distensibility (DI, 1.0 vs. 2.4 mm²/mmHg) was comparable to that of healthy volunteers (2.7 mm²/mmHg).

Conclusion

Functional lumen distensibility measures show that POEM can result in an immediate correction of the nonrelaxing lower esophageal sphincter, which appears similar to that of healthy controls. Intraoperative EGJ profiling may be an important tool to objectively guide the needed extent and completeness of the myotomy during POEM.     

Comparison of Pullout Strength between 3.5-mm Fully Threaded,Bicortical Screws and 4.0-mm Partially Threaded,Cancellous Screws in the Fixation of Medial Malleolar Fractures

Displaced medial malleolus fractures are considered unstable and typically require open reduction and internal fixation for anatomic reduction and early joint range of motion. These fractures are usually fixated with either compression lag screws or tension band wiring depending on the fracture pattern, size of the distal fragment, and bone quality. When fracture fixation fails, it is typically in pullout strength. Failure of primary bone healing can result in nonunion, malunion, and need for revision surgery. The current study wished to explore a potentially stronger fixation technique in regard to pullout strength for medial malleolar fractures compared with traditional cancellous screws. This was a comparative study of the relative pullout strength of 2 fully threaded 3.5-mm bicortical screws versus 2 partially threaded 4.0-mm cancellous screws for the fixation of medial malleolar fractures. Ten fresh-frozen limbs from 5 cadavers, mean age 79 years (range of 65–97 years), were tested using the Instron 8500 Plus system. The median force recorded at 2 mm of distraction using unicortical partially threaded cancellous screws was 116.2 N (range 70.2 to 355.5N) compared with 327.6 N (range 117.5 to 804.3 N) in the fully threaded bicortical screw (P = .04). The unicortical screw fixation displayed only 64.53% of the median strength noted with the bicortical screw fixation at clinical failure. The current study demonstrated statistically significantly greater pullout strength for 3.5-mm bicortical screws when compared with 4.0-mm partially threaded cancellous screws used to fixate medial malleolar fractures in a cadaveric model.     

Recombinant full-length human cytomegalovirus protease has lower activity than recombinant processed protease domain in purified enzyme and cell-based assays

Herpesviruses encode a protease that is essential for virus replication. The protease undergoes cleavage to a processed form during capsid maturation. A recombinant 75 kDa form of the protease from human cytomegalovirus was purified and compared with the recombinant 29 kDa processed form. Modification with an active site titrant suggested that most of each recombinant protease preparation was active (66 and 86%, respectively). Protease activity was compared using a low-molecular weight peptide substrate and the native substrate, capsid assembly protein. In addition, a cell-based assay for both enzymes was developed in which the target sequence of the protease has been fused inframe into the herpes simplex virus VP16 molecule. Cleavage of the fusion protein by the protease releases the carboxyl terminal transactivation domain, resulting in a decrease in the ability of the fusion molecule to transactivate a target promoter linked to a reporter gene in mammalian cells. Results suggest that the 75 kDa form of the enzyme is significantly less active than the 29 kDa form by all criteria.     

Endothelial-dependent vasodilation is reduced in mesenteric arteries from superoxide dismutase knockout mice

OBJECTIVE: Oxidative stress has increasingly been implicated in the development and progression of many vascular diseases. Previous work from our laboratory indicated that peroxynitrite alters vasoactive pathways in endothelial cells, which could potentially reduce vascular relaxation. To test this hypothesis in vivo, we utilized an animal model of endogenous oxidative stress, the CuZn superoxide dismutase (SOD) knockout mouse, to assess vascular function. METHODS: Vascular reactivity of mouse mesenteric arteries was assessed in the presence or absence of inhibitors to nitric oxide synthase (NOS) and/or prostaglandin H synthase (PGHS). Endothelial-dependent function was also measured after the addition of exogenous SOD. Peroxynitrite formation was detected by nitrotyrosine immunofluorescence in mesenteric arteries. RESULTS: Our data indicate that endothelial-dependent relaxation responses to methacholine are highly reduced in SOD-/- mice (P<0.01, ANOVA). In only the wild-type mice, NOS or PGHS inhibition significantly blunted relaxation, suggesting that vasodilators from these pathways are present only in the controls and not in SOD-/- mice. A combination of NOS and PGHS inhibitors reduced methacholine relaxation in both wild type and SOD-/- mice. This residual EDHF-like relaxation was not different between groups. After incubation with exogenous SOD, endothelial-dependent relaxation could be partially restored in SOD-/- mice, due to increased NOS-mediated vasodilation. In addition, peroxynitrite formation was significantly elevated in mesenteric arteries from SOD-/- mice. CONCLUSION: Our data suggest that in a novel animal model of oxidative stress, vessel function is compromised due to alterations in NOS and PGHS-dependent relaxation responses.     

Human papillomavirus-negative ileostomal chronic papillomatous dermatitis

BACKGROUND: Papillomatous stoma-related skin lesions may result from irritant reactions or infection with epidermodysplasia verruciformis human papillomavirus (HPV) types. METHODS: We report upon a papillomatous lesion at the ileostoma of a 63-year-old male with familial adenomatous polyposis and colorectal adenocarcinoma. We thoroughly tested the lesion for HPV using immunohistochemistry, transmission electron microscopy, and polymerase chain reaction analyses. RESULTS: The lesion was a fleshy, multilobulated, and verrucous plaque, with hyperkeratosis, hypergranulosis, acanthosis and marked papillomatosis. The clinical and light microscopic features were suggestive of a condyloma. However, no HPV was detected. CONCLUSIONS: We suggest that the lesion most likely represents chronic papillomatous dermatitis, a reaction to mechanical and/or chemical irritation usually associated with urostomies and only rarely observed with ileostomies. This case highlights the clinical, diagnostic and therapeutic aspects of an unusual cutaneous morbidity associated with ileostomies.     

Physical performance and longevity in aged rats

In humans, physical performance declines with increasing age, and in nondisabled older persons, scores on standardized performance measures, such as walking speed, repeated chair stands, and a balance test, predict the incidence of disability and reduced longevity. Here we show in aged rats (24-month-old Brown Norway x Fischer 344 male rats; n = 48) that conceptually similar performance measures, such as swimming speed and an inclined plane procedure, can be assessed longitudinally, and that over 6 months of follow-up from the age of 24 to 30 months, performance declines progressively with increasing age. High baseline performance scores predict long-term longevity, a relationship that is also found in humans. The application of standardized physical performance measures to a variety of animal models of aging may help to define similarities between species in the underlying mechanisms of the age-related decline in performance, disability, and longevity.