Background The aim of this research was to develop a rat model for vascularized composite allotransplantation (VCA) of the elbow. Methods We developed an animal model for VCA of the elbow in rats. ...Microvascular VCA was performed in 9 rats across a major histocompatibility barrier. Three different immunosuppressive regimens were provided. Joint mobility and weight-bearing capability were assessed throughout 90 days of life. Pedicle patency, bone blood flow, and histologic analyses were performed. Results In the cyclosporine group, forelimb activity was recovered during the postoperative 90 days. The extremity that was operated on was used in daily activities. There was minimal motion or use of the limb in the cyclosporine taper and control groups. The vascular pedicles were patent at the time of death in the cyclosporine-treated group but not in the remaining groups. Micro-computed tomography scan performed 3 months after transplantation revealed union at the bone junctions, and the elbow joint appeared grossly normal on death in the cyclosporine treatment group only. Incomplete healing was observed in the other 2 groups, and the elbow joints were grossly destroyed. Histologic examination revealed normal cartilage and bone cells in the cyclosporine-treated group, whereas the nontreated groups demonstrated lymphocytic infiltration and loss of normal histologic features. Flow cytometry of blood samples obtained on days 14, 30, 60, and 90 showed no recipient cell chimerism in any of the groups. Conclusions We developed an animal model for elbow VCA. Immunosuppressed animals regained nearly normal function of forelimbs and maintained grossly normal elbow cartilage. Without cyclosporine treatment, the elbow transplants were rejected.
Biochemical and histologic data have validated the technique of delayed gadolinium-enhanced MRI, in which the T(1) values of cartilage after penetration of Gd(DTPA)2-allow assessment of the ...glycosaminoglycan (GAG) component of articular cartilage. This work describes the factors that have been found to be important for the practical implementation of the technique: 1) Exercise immediately after intravenous contrast administration was necessary for effective penetration of the contrast into the articular cartilage; 2) double-dose contrast was better than single-dose; 3) after contrast administration, a time window of 30-90 min for the hip, and 2-3 hr for all compartments of the knee proved to be appropriate for assessing articular cartilage; and 4) in some cases of hypointensities in the subchondral patellar bone, decreased penetration of the contrast agent into cartilage from bone was found. With the protocol described, ROIs on T(1) images were reproducible within 15% on two separate imaging sessions, and initial clinical studies demonstrated the possible applications of the technique. Magn Reson Med 45:36-41, 2001.
Since the late 1990s, a number of factors have reduced the threshold for parathyroidectomy in patients with primary hyperparathyroidism. This study examined whether this has translated into increased ...numbers of parathyroid operations over the last decade.
A retrospective analysis was performed of the Patient Episode Database for Wales and English Hospital Episode Statistics annual data from 2000 to 2010 for parathyroidectomy admissions per 100,000 population. Statistical analysis was by linear regression.
Between 2000 and 2010 there were 24,247 parathyroid operations in England and Wales (0.005% of the population), with 3 times as many women treated as men. Overall, incidence of parathyroidectomy rose from 3.3/100,000 population in 2000 to 5.8/100,000 in 2010 (p<0.0001). In England, it increased from 3.3/100,000 population to 5.8/100,000 and in Wales, it increased from 2.4/100,000 population to 4.6/100,000. Despite similar population demographics, the difference in the rate of change between England and Wales was significant (p<0.05). Uptake also varied according to age; in those aged 0-14 years, incidence of parathyroidectomy remained static whereas in all other age groups, uptake of parathyroidectomy increased significantly from 2000 to 2010. Most notably, surgical intervention in those aged 60-74 and >75 years nearly doubled over the decade (p<0.0001).
The incidence of parathyroidectomy in adults has increased significantly in the last decade in England and Wales. This likely reflects changes in population demography, available guidelines, lower threshold for referral, changing surgical approach and the realisation that surgical morbidity is now infrequent.
Microbial Activity at Gigapascal Pressures Sharma, Anurag; Scott, James H.; Cody, George D. ...
Science (American Association for the Advancement of Science),
02/2002, Letnik:
295, Številka:
5559
Journal Article
Recenzirano
We observed physiological and metabolic activity of Shewanella oneidensis strain MR1 and Escherichia coli strain MG1655 at pressures of 68 to 1680 megapascals (MPa) in diamond anvil cells. We ...measured biological formate oxidation at high pressures (68 to 1060 MPa). At pressures of 1200 to 1600 MPa, living bacteria resided in fluid inclusions in ice-VI crystals and continued to be viable upon subsequent release to ambient pressures (0.1 MPa). Evidence of microbial viability and activity at these extreme pressures expands by an order of magnitude the range of conditions representing the habitable zone in the solar system.
Among men who have sex with men, Kaposi's sarcoma is the most common cancer associated with infection with the human immunodeficiency virus (HIV).
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Epidemiologic evidence and molecular evidence ...increasingly suggest that human herpesvirus 8 (HHV-8) is the cause of Kaposi's sarcoma.
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Although HHV-8 is uncommon in the general population in North America, among men who have sex with men, 11 to 20 percent of those who are seronegative for HIV and 30 to 54 percent of those who are seropositive for HIV have detectable antibodies against HHV-8.
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The seroprevalence of HHV-8 is highest among men in this . . .
This study employed Uses and Gratification Theory (UGT), Health Belief Model (HBM) and a mix of techniques to highlight the important role of social media in health communication. A total of 602 ...comments posted by YouTube users as they interacted with news items reporting on Chagas disease were thus analysed. A web-based software called Netlytic was used to capture and conduct text analytics. The sentiment of user comments on each of the five videos selected for this analysis was measured using SentiStrength. This study, therefore, achieved four objectives. First, it determined the most engaging comments amongst YouTube users as they interacted with Chagas disease news information. Second, it identified the most common issues or concerns discussed by YouTube users. Third, it analyzed the extent to which YouTube users commenting about Chagas disease conveyed information related to (a) prevention benefits, (b) barriers, (c) susceptibility to Chagas disease, (d) severity of Chagas and (e) self-efficacy as part of the Health Belief Model. And finally, it measured the levels of positive and negative sentiment in the comments made by YouTube users. Study findings, limitations, and implications for future research have been discussed as well.
Background:
Historically, the lateral extensile approach for calcaneal fracture osteosynthesis has had relatively high rates of wound healing problems. The vascular territory (angiosome) of the ...lateral foot is now known to be dependent upon the lateral calcaneal branch of the peroneal artery (LCBP artery). We postulated that patency of the LCBP artery may have a profound positive impact on incisional wound healing for calcaneal open reduction and internal fixation (ORIF).
Methods:
Ninety consecutive calcaneal fractures that met operative criteria were preoperatively evaluated for the presence of a Doppler signal in the LCBP artery and were followed for the development of wound healing problems.
Results:
Among these 90 fractures, 85 had a positive preoperative Doppler signal along the course of the LCBP artery (94%) and 5 had no Doppler signal (6%). All patients underwent ORIF via a lateral extensile approach. Overall, incisional wound healing problems occurred in 6 of 90 calcaneal incisions (6.5%). All 5 feet that exhibited an absent Doppler signal in the LCPB artery developed an incisional wound healing complication (5/6, approximately 83%): 2 large apical wounds and 3 major dehiscence/slough. However, among the 84 feet that possessed a positive preoperative Doppler signal in the LCBP artery, there was only 1 (1/84, approximately 1%) incisional wound healing problem (P < .0001, Fischer’s exact test). Smokers with a positive Doppler signal in the LCBP artery did not develop a wound healing complication.
Conclusions:
This study suggests a strong link to low incisional wound healing complications for the lateral extensile approach to the calcaneus when a preoperative Doppler signal is present in the LCBP artery. We believe this simple examination should be routinely performed prior to calcaneal ORIF.
Level of Evidence:
Level III, comparative case series.
Acute aortic dissections are a preventable cause of sudden death if individuals at risk are identified and surgically repaired in a non-emergency setting. Although mutations in single genes can be ...used to identify at-risk individuals, the majority of dissection case subjects do not have evidence of a single gene disorder, but rather have the other major risk factor for dissections, hypertension. Initial genome-wide association studies (GWASs) identified SNPs at the FBN1 locus associated with both thoracic aortic aneurysms and dissections. Here, we used the Illumina HumanExome array to genotype 753 individuals of European descent presenting specifically with non-familial, sporadic thoracic aortic dissection (STAD) and compared them to the genotypes of 2,259 control subjects from the Atherosclerosis Risk in Communities (ARIC) study matched for age, gender, and, for the majority of cases, hypertension. SNPs in FBN1, LRP1, and ULK4 were identified to be significantly associated with STAD, and these results were replicated in two independent cohorts. Combining the data from all cohorts confirmed an inverse association between LRP1 rs11172113 and STAD (p = 2.74 × 10−8; OR = 0.82, 95% CI = 0.76–0.89) and a direct association between ULK4 rs2272007 and STAD (p = 1.15 × 10−9; OR = 1.35, 95% CI = 1.23–1.49). Genomic copy-number variation analysis independently confirmed that ULK4 deletions were significantly associated with development of thoracic aortic disease. These results indicate that genetic variations in LRP1 and ULK4 contribute to risk for presenting with an acute aortic dissection.
The Sec1/Munc18 (SM) protein family regulates intracellular trafficking through interactions with individual SNARE proteins and assembled SNARE complexes. Revealing a common mechanism of this ...regulation has been challenging, largely because of the multiple modes of interaction observed between SM proteins and their cognate syntaxin-type SNAREs. These modes include binding of the SM to a closed conformation of syntaxin, binding to the N-terminal peptide of syntaxin, binding to assembled SNARE complexes, and/or binding to nonsyntaxin SNAREs. The SM protein Vps45p, which regulates endosomal trafficking in yeast, binds the conserved N-terminal peptide of the syntaxin Tlg2p. We used size exclusion chromatography and a quantitative fluorescent gel mobility shift assay to reveal an additional binding site that does not require the Tlg2p N-peptide. Characterization of Tlg2p mutants and truncations indicate that this binding site corresponds to a closed conformation of Tlg2p. Furthermore, the Tlg2p N-peptide competes with the closed conformation for binding, suggesting a fundamental regulatory mechanism for SM-syntaxin interactions in SNARE assembly and membrane fusion.
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