Rhabdomyomatous hamartomata of the pharyngeal region with bilateral microtia and aural atresia: A new association?

BACKGROUND: Bilateral microtia with aural atresia is rare. Rhabdomyomatous hamartomata containing salivary tissue, situated bilaterally and symmetrically simulating the palatine (faucial) tonsils, has apparently not been reported. We present the combination of these findings in two unrelated patients. CASES: In the first case, the patient was exposed prenatally to 13-cis-retinoic acid (isotretinoin) and has typical features of this exposure, including bilateral microtia with aural atresia and bilateral 7th nerve palsies. Due to symptoms of obstructive sleep apnea, patient 1 had a "tonsillectomy" and adenoidectomy. Histopathologic studies demonstrated rhabdomyomatous hamartomata containing salivary and striated muscle tissue in place of the palatine tonsils. In the second case, the patient had been prenatally exposed to alcohol, cocaine, and marijuana. He has been noted to have developmental delay and behavioral issues in addition to bilateral microtia with aural atresia. "Tonsillectomy" and adenoidectomy were performed to alleviate chronic upper respiratory infections and snoring. Again, histopathologic studies of the tissue submitted as "tonsil" demonstrated rhabdomyomatous hamartomata containing salivary and muscle tissue. Although an extended banded karyotype and subtelomere panel were normal, a genetic etiology for the second patient's features cannot be excluded. CONCLUSIONS: We hypothesize that the findings of bilateral microtia with aural atresia and rhabdomyomatous hamartomata containing salivary and muscle tissue in the area of the palatine tonsils may represent a newly recognized association, which may have a teratogenic and/or genetic etiology.     

An Inexpensive,Accurate, and Precise Wet-Mount Method for Enumerating Aquatic Viruses

Viruses affect biogeochemical cycling, microbial mortality, gene flow, and metabolic functions in diverse environments through infection and lysis of microorganisms. Fundamental to quantitatively investigating these roles is the determination of viral abundance in both field and laboratory samples. One current, widely used method to accomplish this with aquatic samples is the “filter mount” method, in which samples are filtered onto costly 0.02-μm-pore-size ceramic filters for enumeration of viruses by epifluorescence microscopy. Here we describe a cost-effective (ca. 500-fold-lower materials cost) alternative virus enumeration method in which fluorescently stained samples are wet mounted directly onto slides, after optional chemical flocculation of viruses in samples with viral concentrations of <5 × 10⁷ viruses ml⁻¹. The concentration of viruses in the sample is then determined from the ratio of viruses to a known concentration of added microsphere beads via epifluorescence microscopy. Virus concentrations obtained by using this wet-mount method, with and without chemical flocculation, were significantly correlated with, and had precision equivalent to, those obtained by the filter mount method across concentrations ranging from 2.17 × 10⁶ to 1.37 × 10⁸ viruses ml⁻¹ when tested by using cultivated viral isolates and natural samples from marine and freshwater environments. In summary, the wet-mount method is significantly less expensive than the filter mount method and is appropriate for rapid, precise, and accurate enumeration of aquatic viruses over a wide range of viral concentrations (≥1 × 10⁶ viruses ml⁻¹) encountered in field and laboratory samples.     

The Effect of Glucagon-Like Peptide 1 Receptor Agonists on Weight Loss in Type 2 Diabetes: A Systematic Review and Mixed Treatment Comparison Meta-Analysis

Aims

To determine the effects of glucagon-like peptide-1 receptor agonists compared with placebo and other anti-diabetic agents on weight loss in overweight or obese patients with type 2 diabetes mellitus.

Methods

Electronic searches were conducted for randomised controlled trials that compared a glucagon-like peptide-1 receptor agonist therapy at a clinically relevant dose with a comparator treatment (other type 2 diabetes treatment or placebo) in adults with type 2 diabetes and a mean body mass index ≥ 25kg/m². Pair-wise meta-analyses and mixed treatment comparisons were conducted to examine the difference in weight change at six months between the glucagon-like peptide-1 receptor agonists and each comparator.

Results

In the mixed treatment comparison (27 trials), the glucagon-like peptide-1 receptor agonists were the most successful in terms of weight loss; exenatide 2mg/week: -1.62kg (95% CrI: -2.95kg, -0.30kg), exenatide 20μg: -1.37kg (95% CI: -222kg, -0.52kg), liraglutide 1.2mg: -1.01kg (95%CrI: -2.41kg, 0.38kg) and liraglutide 1.8mg: -1.51 kg (95% CI: -2.67kg, -0.37kg) compared with placebo. There were no differences between the GLP-1 receptor agonists in terms of weight loss.

Conclusions

This review provides evidence that glucagon-like peptide-1 receptor agonist therapies are associated with weight loss in overweight or obese patients with type 2 diabetes with no difference in weight loss seen between the different types of GLP-1 receptor agonists assessed.     

Guidelines for the development and validation of new potency assays for the evaluation of umbilical cord blood

The following commentary was developed by the National Marrow Donor Program Cord Blood Advisory Group and is intended to provide an overview of umbilical cord blood (UCB) processing, summarize the current state of potency assays used to characterize UCB, and define limitations of the assays and future needs of the cord blood banking and transplant community. The UCB banking industry is eager to participate in the development of standardized assays to uniformly characterize cellular therapy products that are manufactured in a variety of ways. This paper describes the desired qualities of these assays and how the industry proposes to co-operate with developers to bring relevant assays to market. To that end, the National Marrow Donor Program (NMDP) Cord Blood Bank Network is available to serve as a resource for UCB testing material, research and development consulting, and product/assay testing in an accredited UCB manufacturing environment.     

External labeling of galactose in surface membrane glycoproteins of the intact myelin sheath.

The molecular organization of surface galactose residues in glycoproteins of the intact myelin sheath was investigated using the enzymatic membrane probe, galactose oxidase. Rat spinal cords treated under physiological conditions with this nonpermanent probe were labeled specifically in galactose residues by reduction with tritiated sodium borohydride. The enzymatically modified proteins from isolated myelin were analyzed electrophoretically and their specific radioactivities determined. Results indicated tritium label associated with a surprising variety of high molecular weight proteins. The most extensively labeled peak corresponded to the major myelin glycoprotein as indicated by the coincidence of tritium label with that of [14C]fucose used as an internal marker for the glycoproteins. The radioactivity associated with this protein was 1.1 to 2.7 times higher after treatment with galactose oxidase when compared to reduction in the absence of the enzyme and 1.4 to 4.8 times higher when oxidized and reduced after prior treatment with neuraminidase. The results suggest a complex heterogeneity of minor glycoproteins associated with isolated myelin. It is concluded that from this complexity of glycoproteins, a major glycoprotein is at least partially localized on the external surface of either the intact myelin sheath or the closely associated oligodendroglial plasma membrane. Such a localization of this glycoprotein and the probable localization of the other glycoproteins enhances their potential role in specific interactions in the process of mpyelination or myelin maintenance.