Role of anterior scalene muscle hypertrophy in thoracic outlet syndrome

A case of hypertrophic anterior scalene muscle surgically treated is reported. The patient suffered from upper limb intermittent claudication at any sustained upper extremity activity such as lifting a weight or opening and closing the hand with the arm abducted. Doppler and angiographic study showed significant compression of subclavian artery with hyperabduction and Adson manoeuver. Simple anterior scalenotomy was followed by prompt recovery of symptoms. The results of scalenotomy and other surgical approaches to thoracic outlet syndrome are reviewed in the literature. The most common anomalies of anterior scalene muscle in the TOS are also described. Doppler and arteriographic study in different functional positions are necessary in the evaluation of subclavian artery compression by osseous or muscular structures. In the reported case scalenotomy was at least as effective as 1st rib resection.     

Electronic textbooks as a professional resource after dental school

In two previous studies of dental students' attitudes about the VitalSource Bookshelf, a digital library of dental textbooks, students expressed negative opinions about owning and reading electronic textbooks. With the assumption that dentists would find the digital textbooks useful for patient care, the authors surveyed recent graduates to determine if their attitude toward the VitalSource Bookshelf had changed. A brief survey was sent to 119 alumni from the classes of 2009 and 2010 of one U.S. dental school. Forty-seven (39.5 percent) completed the questionnaire. Eighteen respondents (48.3 percent) reported using the e-textbooks often or sometimes. The twenty-nine dentists who said they have not used the collection since graduation reported preferring print books or other online sources or having technical problems when downloading the books to a new computer. Only five respondents selected the VitalSource Bookshelf as a preferred source of professional information. Most of the respondents reported preferring to consult colleagues (37.8 percent), the Internet (20 percent), or hardcopy books (17.8 percent) for information. When asked in an open-ended question to state their opinion of the Bookshelf, nineteen (42.2 percent) responded positively, but almost one-third of these only liked the search feature. Six respondents reported that they never use the program. Twenty-two said they have had technical problems with the Bookshelf, including fifteen who have not been able to install it on a new computer. Many of them said they have not followed up with either the dental school or VitalSource support services to overcome this problem. Our study suggests that dentists, similar to dental students, dislike reading electronic textbooks, even with the advantage of searching a topic across more than sixty dental titles.     

Implant-supported mandibular splinting affects temporomandibular joint biomechanics

Objectives: Mandibular functional movements lead to complex deformations of bony structures. The aim of this study was to test whether mandibular splinting influences condylar kinematics and temporomandibular joint (TMJ) loading patterns. Materials and methods: Six subjects were analyzed by means of dynamic stereometry during jaw opening–closing with mandibles unconstrained as well as splinted transversally by a cast metal bar fixed bilaterally to two implant pairs in the (pre)molar region. Statistical analysis was performed by means of ANOVAs for repeated measurements (significance level α=0.05). Results: Transversal splinting reduced mandibular deformation during jaw opening–closing as measured between two implants in the (pre)molar region on each side of the mandible significantly by 54%. Furthermore, splinting significantly reduced the distance between lateral condylar poles (average displacement vector magnitude of each pole: 0.84±0.36 mm; average mediolateral displacement component: 45±28% of the magnitude) and led to a medial displacement of their trajectories as well as a mediolateral displacement of stress‐field paths. Conclusions: During jaw opening–closing, splinting of the mandible leads to a significant reduction of mandibular deformation and intercondylar distance and to altered stress‐field paths, resulting in changed loading patterns of the TMJ structures. To cite this article:
Zaugg B, Hämmerle CHF, Palla S, Gallo LM. Implant‐supported mandibular splinting affects temporomandibular joint biomechanics.
Clin. Oral Impl. Res. 23 , 2012; 897–901
doi: 10.1111/j.1600‐0501.2011.02241.x     

Proteinuria in IgA nephropathy

Clinicopathological data in 74 patients with IgA nephropathy were analyzed with special attention to level of proteinuria and its prognostic significance in this disease. Excretion rates exceeding 3 g per day (heavy), in the range of 1 to 2.9 g (moderate) and under 1 g per day (mild) each occurred in approximately equal proportions of patients. One-sixth of those with more than 1 g developed end-stage renal failure, while serum creatinine never exceeded 2 mg/dl in any with mild proteinuria. "Renal survival" (serum creatinine of 2 mg/dl or less) at five years after presentation was 100% in patients with persistently mild proteinuria, 87% in those whose protein excretion reached the moderate range, and 69% when heavy or nephrotic range proteinuria developed. Of significance, only rarely did mild proteinuria at presentation increase to higher levels. A correlation existed between level of protein excretion and severity of mesangial, segmental or global proliferation, glomerulosclerosis, podocyte effacement, interstitial infiltration, tubular atrophy and vascular sclerosis, even in patients with unimpaired renal function. Moderate or heavy proteinuria typically preceded the onset of hypertension and occurred prior to the development of renal insufficiency. Our results underscore magnitude of proteinuria as an early marker of glomerular damage in the prognosis of IgA nephropathy.     

C-C chemokine receptor 2 and sarcoidosis: association with Lofgren's syndrome

Sarcoidosis is thought to result from the interaction between an unknown environmental antigenic trigger and the host's genetic susceptibility. We hypothesized that sarcoidosis, or one of the disease subsets, could be associated with single nucleotide polymorphisms of C-C chemokine receptor 2 (CCR2) gene. Eight single-nucleotide polymorphisms in CCR2 were studied in a total of 304 Dutch individuals (90 non-L?fgren sarcoidosis, 47 L?fgren's syndrome, 167 control subjects). From the investigated CCR2 polymorphisms, nine haplotypes were deduced (haplotypes 1-9). In patients with L?fgren's syndrome, a strongly significant increase in the frequency of CCR2-haplotype 2, which includes four unique alleles (A at nucleotide position -6752, A at 3,000, T at 3,547, and T at 4,385), was observed compared with control subjects (74% vs. 38% respectively, p < 0.0001), whereas no difference was found between non-L?fgren sarcoidosis and control subjects (both 38%). The association between CCR2-haplotype 2 carriage frequency and L?fgren's syndrome (odds ratio, 4.4; p < 0.0001) remained significant after adjustment for human leukocyte antigen haplotype DRB1*0301-DQB1*0201 (odds ratio, 11.5; p < 0.0001) and female sex (odds ratio, 3.2; p = 0.003), two known risk factors for L?fgren's syndrome. In conclusion, this report describes a strong association between CCR2-haplotype 2 and L?fgren's syndrome. Further studies are needed to understand the molecular mechanisms underlying this association.     

Localization of denaturation bubbles in random DNA sequences

We study the thermodynamic and dynamic behaviors of twist-induced denaturation bubbles in a long, stretched random sequence of DNA. The small bubbles associated with weak twist are delocalized. Above a threshold torque, the bubbles of several tens of bases or larger become preferentially localized to AT-rich segments. In the localized regime, the bubbles exhibit "aging" and move around subdiffusively with continuously varying dynamic exponents. These properties are derived by using results of large-deviation theory together with scaling arguments and are verified by Monte Carlo simulations.     

Guidelines for the Perplexed: How to Maximize Colonoscopy Efficiency During the COVID-19 Pandemic

Digestive Diseases and Sciences -     

Cathelicidins and innate defense against invasive bacterial infection

Cathelicidins are small cationic peptides that possess broad-spectrum antimicrobial activity. These gene-encoded 'natural antibiotics' are produced by several mammalian species on epithelial surfaces and within the granules of phagocytic cells. Since their discovery over a decade ago, cathelicidins have been speculated to function within the innate immune system, contributing to a first line of host defense against an array of microorganisms. Consequently, cathelicidins have captured the interest of basic investigators in the diverse fields of cell biology, immunology, protein chemistry and microbiology. A burgeoning body of experimental research now appears to confirm and extend the biological significance of these fascinating molecules. This article reviews the latest advances in the knowledge of cathelicidin antimicrobial peptides, with particular emphasis on their role in defense against invasive bacterial infection and associations with human disease conditions.     

Different modalities of classification and prognostic significance of ventricular arrhythmias after acute myocardial infarct. Prospective study

In our study we compared the prognostic significance of clinical variables, laboratory results and different classification models of ventricular ectopic beats recorded by means of a pre-discharge 24 hour ambulatory electrocardiographic monitoring, in 210 survivors of acute myocardial infarction. In addition a full multivariate analysis of the factors affecting survival time was carried out using Cox's proportional hazards (multiple) regression model. Multivariate stepwise discriminant analysis identified hypertension, congestive heart failure assessed by Killip class, and the grading system for ventricular arrhythmias as the most important prognostic variables. When Moss grading system for ventricular arrhythmias was used, the relative risk was a superior as heavy Moss grading system (Moss 2 vs Moss 1 and Moss 3-4 vs Moss 1, relative risk = 1.2 and 3.6 total death, respectively). Furthermore, the hazard ratio of Moss grading system was higher utilizing as comparison patients without ventricular ectopic beats (relative risk = 1.7 for Moss 2 and 5.3 for Moss 3-4) than patients with ventricular ectopic beats less than one/hour (relative risk = 1.2 for Moss 2 and 3.7 for Moss 3-4). Thus, in survivors of acute myocardial infarction, a rational and useful ventricular ectopic beats categorization includes both frequency and the presence or absence of malignant characteristics.