Effect of occlusal splint therapy on maximum bite force in individuals with moderate to severe attrition of teeth

ObjectiveThe purpose of the pilot study was to determine the effect of restoring lost occlusal vertical dimension (OVD) due to attrition on maximum bite force in humans.MethodologyA total of 124 subjects in age range of 25–40 years, with moderate to severe attrition, having full complement of teeth were screened according to inclusion and exclusion criteria. After consent, occlusal vertical dimension was assessed by employing mechanical and physiological methods in the experimental group and a maxillary canine guided hard splint was fabricated for each subjects fulfilling inclusion criteria and with positive consent (78). Bite force in experimental group was measured before, immediately after delivery of splint and subsequently at an interval of four, eight, and twelve weeks. Due loss during follow up, only 50 subjects could be available for bite force recording till 12 weeks. Bite force of age, gender, height and weight matched controls with no signs of attrition was also measured for comparison.ResultsBite force of the experimental group was found to be significantly less than the matched controls (P = 0.000) initially. After delivery of splint, bite force values increased progressively till twelve weeks. However comparison of bite force values of experimental group with control group showed no significant difference at end of eight (P = 0.008) and twelve weeks (P = 0.162).ConclusionIt was concluded that maximum bite force increases with restoration of lost vertical using splint therapy. A time period of 8–12 weeks is required to restore the maximum bite force value approximately similar to matched controls.     

Off-pump or on-pump coronary artery bypass grafting—a dilemma in elderly

Background

Off-pump coronary artery bypass graft surgery (OPCAB) has been performed for many years, but its use is increasing in frequency, and it remains an open question whether OPCAB is associated with better outcomes than on-pump coronary artery bypass graft (CABG) surgery especially in patients with age >65 years.

Methods

We randomly assigned patients 65 years of age or older who were scheduled for elective first-time CABG to undergo the procedure either without cardiopulmonary bypass (off-pump CABG) or with it (on-pump CABG). The primary end point was a composite of death, stroke, myocardial infarction, repeat revascularization, or new renal-replacement therapy at 30 days and at 12 months after surgery.

Results

A total of 581 patients underwent randomization. At 30 days after surgery, there was no significant difference between patients who underwent off-pump surgery and those who underwent on-pump surgery in terms of the composite outcome (9.8 vs. 10.1 %; odds ratio, 0.98; 95 % confidence interval [CI], 0.57 to 1.68; P?=?0.95) or four of the components (death, stroke, myocardial infarction, or new renal-replacement therapy). Repeat revascularization occurred more frequently after off-pump CABG than after on-pump CABG (1.5 vs. 0.3 %; odds ratio, 3.93; 95 % CI, 0.43 to 35.39; P?=?0.22). At 12 months, there was no significant between-group difference in the composite end point (13.1 vs. 13.3 %; hazard ratio, 0.98; 95 % CI, 0.60 to 1.58; P?=?0.94) or in any of the individual components.

Conclusions

In patients 65 years of age or older, there was no significant difference between on-pump and off-pump CABG with regard to the composite outcome of death, stroke, myocardial infarction, repeat revascularization, or new renal-replacement therapy within 30 days and within 12 months after surgery.

     

Optimal Planar Flow Network Designs for Tissue Engineered Constructs with Built-in Vasculature

Convective delivery of nutrients is important to enhance mass transport within tissue engineered (TE) products. Depending on the target tissue, an ideal TE product will have an integrated microvasculature that will eliminate mass transport limitations that can occur during product growth in vitro and integration in vivo. A synthetic approach to develop microvasculature involves development of network designs with efficient mass transfer characteristics. In this paper, utilizing a planar bifurcating network as a basis, we develop an approach to design optimal flow networks that have maximum mass transport efficiency for a given pressure drop. We formulated the optimization problem for a TE skin product, incorporating two types of duct flow, rectangular and square, and solved using a generalized reduced gradient algorithm. Under the conditions of this study, we found that rectangular ducts have superior mass transport characteristics than square ducts. Microvascular area per volume values obtained in this work are significantly greater than those reported in the literature. We discuss the effect of network variables such as porosity and generations on the optimal designs. This research forms the engineering basis for the rational development of TE products with built-in microvasculature and will pave the way to design complex flow networks with optimal mass transfer characteristics.     

Cavernous sinus haemangioma: systematic review and pooled analysis relating to a rare skull base pathology

Neurosurgical Review - Cavernous sinus haemangiomas (CSHs) are rare malformations of the microcirculation arising from the cavernous sinus. A systematic review and pooled data analysis of the...     

Exercise‐Induced Ventricular Arrhythmias and Cardiovascular Death

Background: Exercise‐induced ventricular arrhythmias (EIVA) are frequently observed during exercise testing. However, the clinical guidelines do not specify their significance and so we examined this issue in our population. Methods: A retrospective analysis of prospectively collected data was performed on 5754 consecutive male veterans referred for exercise testing at two university‐affiliated Veterans Affairs Medical Centers. Exercise test responses were recorded and cardiovascular mortality was assessed after a mean follow‐up of 6 ± 4 years. EIVA were defined as frequent premature ventricular complexes (PVCs) constituting more than 10% of all ventricular depolarizations during any 30‐second ECG recording, or a run of three or more consecutive PVCs during the exercise test or recovery. Results: EIVA occurred in 426 patients (7.4%). There were 550 (10.6%) cardiovascular deaths during follow‐up. Seventy two (17%) patients with EIVA died of cardiovascular causes, whereas 478 (9.0%) of patients without EIVA died of cardiovascular causes (P < 0.001). Patients with EIVA had a higher prevalence of cardiovascular disease, resting PVCs, resting ST depression, and ischemia during exercise than patients without EIVA. In a Cox hazards model adjusted for age, cardiovascular disease, exercise‐induced ischemia, ECG abnormalities, exercise capacity and risk factors, EIVA was significantly associated with time to cardiovascular death. The combination of both resting PVCs and EIVA was associated with the highest hazard ratio. Conclusions: EIVA are independent predictors of cardiovascular mortality after adjusting for other clinical and exercise test variables; combination with resting PVCs carries the highest risk.     

Characterizing asthma from a drop of blood using neutrophil chemotaxis

Asthma is a chronic inflammatory disorder that affects more than 300 million people worldwide. Asthma management would benefit from additional tools that establish biomarkers to identify phenotypes of asthma. We present a microfluidic solution that discriminates asthma from allergic rhinitis based on a patient’s neutrophil chemotactic function. The handheld diagnostic device sorts neutrophils from whole blood within 5 min, and generates a gradient of chemoattractant in the microchannels by placing a lid with chemoattractant onto the base of the device. This technology was used in a clinical setting to assay 34 asthmatic (n = 23) and nonasthmatic, allergic rhinitis (n = 11) patients to establish domains for asthma diagnosis based on neutrophil chemotaxis. We determined that neutrophils from asthmatic patients migrate significantly more slowly toward the chemoattractant compared with nonasthmatic patients (P = 0.002). Analysis of the receiver operator characteristics of the patient data revealed that using a chemotaxis velocity of 1.55 μm/min for asthma yields a diagnostic sensitivity and specificity of 96% and 73%, respectively. This study identifies neutrophil chemotaxis velocity as a potential biomarker for asthma, and we demonstrate a microfluidic technology that was used in a clinical setting to perform these measurements.Asthma is a chronic inflammatory disorder of the lungs that is associated with airway hyperresponsiveness (AHR) and obstructed airflow (1), affecting more than 300 million people worldwide (2). Over the past 30 y, asthma prevalence has increased significantly in many populations, with some indications that prevalence may be reaching a plateau in the developed world. Significant progress has been made in identifying primary mediators involved in the pathophysiology of asthma. Several cell types, such as T helper cells (T_H1/T_H2), dendritic cells, mast cells, macrophages, eosinophils, and neutrophils play central roles in the pathology of asthma (4–7). Additionally, various cytokines that regulate the leukocyte trafficking, such as interleukins, IFN-γ, and TNF-α, have been identified and targeted in drug therapies. The recruitment of leukocytes to the lungs, particularly eosinophils and neutrophils, is central to the pathogenesis of asthma. Increased numbers of eosinophils are prominently observed in the lung tissue and bronchoalveolar lavage (BAL) fluid for most asthmatics (5). Neutrophils play a more critical role in severe asthma, where elevated counts of neutrophils are often observed in the BAL fluid (7). An overview of the role of neutrophils in asthma is shown in Fig. 1A. Although significant progress has been made in uncovering mediators in the pathology of asthma, these gains have not yet greatly improved our ability to define clinically relevant phenotypes of asthma in patients.Open in a separate windowFig. 1.Overview of different diagnostic techniques and the role of neutrophils in the pathology of asthma. (A) Summary of the role of neutrophils in the pathology of asthma, showing neutrophil adhesion and transendothelial migration; chemotaxis mediated by macrophages and T-helper cells; and neutrophilia in the lung tissue that leads to airway remodeling and airflow obstruction. (B) Proposed microfluidic method (more details in Fig. S1) for phenotyping asthma patients by measuring upstream of the asthma pathology with rapid neutrophil sorting on a P-selectin–coated surface (1); neutrophil chemotaxis monitored with high-throughput microscopy and automatically tracked with software (2); and asthma characterization on the basis of chemotaxis outputs (3). (C) Traditional clinical asthma diagnostic methods occur downstream of the asthma pathophysiology by measuring the effect of leukocyte inflammation on airway obstruction, nitric oxide output, or clinical symptoms.Asthma is diagnosed clinically by physicians, informed by the patient’s medical history, spirometry tests that measure lung function, reversibility of AHR, and several other potential metrics (8). These diagnostic techniques measure the effects of the inflammatory response in the lung by assessing airway constriction, nitric oxide production, and the resulting clinical symptoms. However, all of these diagnostic tests require patient compliance, which can be challenging when diagnosing children or the elderly (9). Additionally, many asthma diagnostic tests partially rely on the patient experiencing clinical symptoms that are variable during or around the visit to the physician. Perhaps these common characteristics of current diagnostic techniques contribute to difficulties in diagnosing asthma, particularly in certain subpopulations. For example, in a recent Canadian study involving ∼500 obese and nonobese subjects, Aaron et al. (10) found that ∼30% of the test subjects had been falsely diagnosed with asthma by physicians. Additionally, it is well established that the elderly are consistently underdiagnosed for asthma (11, 12). Therefore, additional tools are needed to improve the diagnosis of asthma. Furthermore, current asthma assessments do not inform the clinician of disease severity, expected clinical course, and risk of exacerbations.To improve characterization of asthma in the clinic, we have developed a handheld microfluidic chip that can identify functional measures of asthma from a drop of whole blood. Microfluidic systems have several characteristics that make them well-suited for clinical use, including low sample-volume requirements (13, 14); simple integration with automated fluid handling systems (15); and diffusion-dominant laminar fluidic phenomena that allow for precise control of a cell’s microenvironment (16–18). Indeed, microfluidic-based tools are increasingly being used in clinical research for diagnostic purposes (19–26). Neutrophils have been used to diagnose clinical conditions in human patients based on proteomic and genomic analysis (22) and chemotaxis behavior (23, 27), demonstrating that assays measuring cell function can be used for diagnostics. In this work, we assay the neutrophil chemotactic function in a blind study to identify quantitative domains that can be used to discriminate asthma from nonasthmatic allergic rhinitis. This approach of directly measuring the effector cell in the pathology of asthma differs from traditional diagnostic tests, which measure the variable effect of inflammation on airway constriction (Fig. 1 B and C and Table S1). Importantly, we developed methods to simplify the sample preparation, assay protocol, and data analysis that offer significant time savings over traditional macroscale (28–30) and microscale (18) chemotaxis techniques, allowing for the translation of the technology into the clinic. We analyzed 34 patients, and discovered that neutrophil chemotaxis can be used to discriminate asthma from nonasthmatic, allergic rhinitis patients with sensitivity and specificity of 96% and 73%, respectively. The results of the clinical application of our microfluidic device represent a first step demonstration of how asthma can potentially be diagnosed and managed based on cellular function, rather than largely by clinical observations.     

Genetic portrait study for 23 Y-STR loci in the population of Rajasthan,India

International Journal of Legal Medicine - This study was conducted to come up with data on Y-STR markers for the population of Rajasthan comprising of the western arid region of India. Y-STR...