Clinical Symptoms Contributing to Zenker\u27s Diverticulum Repair: A Retrospective Review

Objective: Zenker\u27s diverticulum (ZD) is usually associated with dysphagia and other symptoms due to the interrelated functions of several systems. Surgical management of ZD is effective for all sizes of diverticula, but not all patients decide to undergo surgery. The purpose of this study was to determine the relationship between clinical presentation and patients\u27 decision to undergo surgical repair. Subjects and methods: This is a retrospective study including 165 patients with ZD treated over the last 11 years. Data collection includes patients\u27 chief complaints and symptoms, medical history, findings on radiologic swallow evaluations, and patients\u27 decision to undergo surgery. Pearson correlation and logistic regression analysis were performed. Results: Among our cohort, dysphagia was the most prevalent symptom (89.1%), followed by cough (65.5%) and regurgitation (58.8%). Dysphonia was prevalent among patients with a small-sized ZD. Our logistic regression model showed that patients\u27 decision to undergo surgical repair could be predicted by diverticula size (β=1.10, p=0.002) and the presence of dysphagia (β=1.91, p=0.005), cough (β=1.01, p=0.042), and dysphonia (β=-1.37, p=0.024). Conclusion: Patients\u27 decision to undergo surgery usually involves interrelated factors, including symptomatic burden, presence of comorbidities, and recommendation of the surgeon. This study has identified that diverticula size and the presence of dysphagia, cough, and dysphonia are significant factors influencing decision-making for surgical repair in patients with ZD

Quantitative and qualitative differences in subcutaneous adipose tissue stores across lipodystrophy types shown by magnetic resonance imaging

BACKGROUND: Lipodystrophies are characterized by redistributed subcutaneous fat stores. We previously quantified subcutaneous fat by magnetic resonance imaging (MRI) in the legs of two patients with familial partial lipodystrophy subtypes 2 and 3 (FPLD2 and FPLD3, respectively). We now extend the MRI analysis across the whole body of patients with different forms of lipodystrophy. METHODS: We studied five subcutaneous fat stores (supraclavicular, abdominal, gluteal, thigh and calf) and the abdominal visceral fat stores in 10, 2, 1, 1 and 2 female subjects with, respectively, FPLD2, FPLD3, HIV-related partial lipodystrophy (HIVPL), acquired partial lipodystrophy (APL), congenital generalized lipodystrophy (CGL) and in six normal control subjects. RESULTS: Compared with normal controls, FPLD2 subjects had significantly increased supraclavicular fat, with decreased abdominal, gluteal, thigh and calf subcutaneous fat. FPLD3 subjects had increased supraclavicular and abdominal subcutaneous fat, with less severe reductions in gluteal, thigh and calf fat compared to FPLD2 subjects. The repartitioning of fat in the HIVPL subject closely resembled that of FPLD3 subjects. APL and CGL subjects had reduced upper body, gluteal and thigh subcutaneous fat; the APL subject had increased, while CGL subjects had decreased subcutaneous calf fat. Visceral fat was markedly increased in FPLD2 and APL subjects. CONCLUSION: Semi-automated MRI-based adipose tissue quantification indicates differences between various lipodystrophy types in these studied clinical cases and is a potentially useful tool for extended quantitative phenomic analysis of genetic metabolic disorders. Further studies with a larger sample size are essential for confirming these preliminary findings

A proposed novel multiplexed near field Terahertz microscope

There is burgeoning interest in the possibility that 'terahertz' measurements will yield novel biological information. This relates primarily to the fact that proteins and other large molecules have many low frequency modes which fall in the terahertz region and which may give structural information. Additionally there is interest in possible measurements of 'mechanical' resonance modes of membranes in structures such as liposomes. A fundamental problem with terahertz measurements is that, since one terahertz has a wavelength of three hundred microns, diffraction limited imaging can only yield a resolution of the order of half a millimetre, too large for items of biological interest. The solution is well known – scanning near field microscopy – which can yield resolution far below the wavelength. However the solution comes with a problem, namely very slow data rates and hence very long imaging times. We describe a proposed multiplexed near field microscope which can collect fully spectrally resolved information on up to ~100 pixels simultaneously using one high quality detector. Resolution of a few microns appears feasible (possibly rather better at the top end of the terahertz range.) The microscope is ideally suited for use with coherently enhanced synchrotron radiation sources provided they run in CW mode

Predicting Abdominal Adipose Tissue among Women with Familial Partial Lipodystrophy

The objective of the study was to determine correlations between magnetic resonance imaging (MRI) measures of truncal adiposity (trunk fat percentage [TrF %(MRI)], visceral adipose tissue [VAT], and subcutaneous abdominal adipose tissue [SAT]), simple clinical measures (body mass index [BMI], waist circumference [WC], and waist-to-hip ratio [WHR]), and bioelectrical impedance analysis (BIA)-derived measures (total fat percentage [TF %] and TrF %(BIA)) in female patients with familial partial lipodystrophy (FPLD). Our secondary aim was to generate and cross-validate predictive equations for VAT and SAT using these simple clinical and BIA-derived variables. Measures of truncal adiposity were measured using 1.5-T MRI (VAT, SAT, and TrF %(MRI)) and Tanita (Tokyo, Japan) 8-electrode body composition analyzer BC-418 (TrF %(BIA)) in 13 female FPLD patients. Pearson correlation coefficients were determined among the various adiposity parameters (BMI, WC, WHR, SAT, VAT, TrF %(MRI), TrF %(BIA), and TF %). Equations to estimate VAT and SAT were determined among 6 of the 13 FPLD subjects using multilinear regression analysis, and the best equations were then cross-validated in the remaining 7 subjects. Variables entered into the model included age, BMI, WC, WHR, TrF %(BIA), and TF %. The TrF %(MRI) showed moderate correlation (r = 0.647, P = .02) with the TrF %(BIA), but the discrepancy between the 2 variables increased with increasing truncal adiposity. The strongest correlate for TrF %(MRI) was BMI (r = 0.886, P \u3c .0001). Visceral adipose tissue was poorly associated with simple clinical measures of BMI, WC, and WHR, but was inversely correlated with TF %, TrF %(BIA), and SAT. The TF % was the strongest correlate for both SAT and VAT. Thus, the best regression equation for VAT included age, BMI, WC, and TF % (R(2) = 1.0), whereas that for SAT only included TF % (R(2) = 0.75). The corresponding standard error of the estimate for the predictive equations was approximately 0.03 % and 18.5 % of the mean value of VAT and SAT, respectively. In the cross-validation study, differences between predicted and observed values of SAT were larger than those of VAT. We conclude that, among female FPLD patients, (1) no simple clinical anthropometric measure correlates well with VAT, whereas BMI correlates well with SAT; (2) BIA measure of TF % most strongly correlated with both VAT and SAT; and (3) based on the cross-validation study, VAT but not SAT could be more reliably estimated using the regression equations derived

Concentration dependent structural ordering of poloxamine 908 on polystyrene nanoparticles and their modulatory role on complement consumption

Adsorption of poloxamine 908, a tetrafunctional polyethylene oxide (PEO)-polypropylene oxide ethylenediamine block copolymer, onto the surface of monodispersed polystyrene nanoparticles (232±0.33 nm) follows a bimodal pattern. Initially, the isotherm follows a Langmuir profile with a plateau observable over a very narrow equilibrium poloxamine concentration (0.0018–0.0031 mM). The isotherm then begins to rise again, reaching a final plateau at equilibrium poloxamine concentrations above 0.0089 mM. Similarly, the profile of the adsorbed layer thickness of poloxamine on the surface of nanoparticles is bimodal. The first plateau corresponds to a thickness of 4.6±0.07 nm, which occurs over the same range of poloxamine concentrations as in the initial plateau of the adsorption isotherm. The second plateau corresponds to a thickness of 9.53±0.32nm, observable at a minimum poloxamine concentration of 0.0067 mM. By using a calculated radius of gyration of a PEO chain in poloxamine as 3.1 nm, these observations reflect dynamic changes in the arrangement of surface projected PEO chains; a mushroom-like conformation at the first plateau region of the adsorption isotherm, followed by a transition into a brush-like conformation. These conformational changes are also reflected in rheological studies; the apparent viscosity of nanoparticles in which the PEO chains are in mushroom conformation is considerably higher than particles displaying the brush conformation. Further, atomic force microscopy studies (height profile and phase lag measurements) corroborated that the proposed poloxamine concentration dependent transition of surface associated PEO chains from mushroom to brush appearance is conserved when nanoparticles are dried under ambient conditions. Finally, we compared the influence of the surface PEO characteristics on complement consumption in human serum. Our results show complement-activating nature of all poloxamine-coated nanoparticles. However, complement consumption is reduced substantially with particles bearing a minimum of 11448 poloxamine molecules on their surface, thus demonstrating the importance of PEO surface density as well as brush conformation in suppressing complement consumption. This relationship between surface characteristics of poloxamine nanoparticles and their in vivo performance is discussed

A comparison of uniaxial and polyaxial suspended germanium bridges in terms of mechanical stress and thermal management towards a CMOS compatible light source

Germanium (Ge) is a promising candidate for a CMOS compatible laser diode.This is due to its compatibility with Silicon (Si) and its ability to be converted into a direct band gap material by applying tensile strain. In particular uniaxial suspended Ge bridges have been extensively explored due to their ability to introduce high tensile strain. There have been two recent demonstrations of low-temperature optically-pumped lasing in these bridges but no room temperature operation accredit to insufficient strain and poor thermal management. In this paper we compare uniaxial bridges with polyaxial bridges in terms of mechanical stress and thermal management using Finite Element Modelling (FEM). The stress simulations reveal that polyaxial bridges suffer from extremely large corner stresses which prevent larger strain from being introduced compared with uniaxial bridges. Thermal simulations however reveal that they are much less thermally sensitive than uniaxial bridges which may indicate lower optical losses. Bridges were fabricated and Raman spectroscopy was used to validate the results of the simulations. We postulate that polyaxial bridges could offer many advantages over their uniaxial counterparts as potential laser device