Membrane raft organization is more sensitive to disruption by (n-3) PUFA than nonraft organization in EL4 and B cells

Model membrane and cellular detergent extraction studies show (n-3) PUFA predominately incorporate into nonrafts; thus, we hypothesized (n-3) PUFA could disrupt nonraft organization. The first objective of this study was to determine whether (n-3) PUFA disrupted nonrafts of EL4 cells, an extension of our previous work in which we discovered an (n-3) PUFA diminished raft clustering. EPA or DHA treatment of EL4 cells increased plasma membrane accumulation of the nonraft probe 1,1'-dilinoleyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate by ~50-70% relative to a BSA control. F?rster resonance energy transfer imaging showed EPA and DHA also disrupted EL4 nanometer scale nonraft organization by increasing the distance between nonraft molecules by ~25% compared with BSA. However, changes in nonrafts were due to an increase in cell size; under conditions where EPA or DHA did not increase cell size, nonraft organization was unaffected. We next translated findings on EL4 cells by testing if (n-3) PUFA administered to mice disrupted nonrafts and rafts. Imaging of B cells isolated from mice fed low- or high-fat (HF) (n-3) PUFA diets showed no change in nonraft organization compared with a control diet (CD). However, confocal microscopy revealed the HF (n-3) PUFA diet disrupted lipid raft clustering and size by ~40% relative to CD. Taken together, our data from 2 different model systems suggest (n-3) PUFA have limited effects on nonrafts. The ex vivo data, which confirm previous studies with EL4 cells, provide evidence that (n-3) PUFA consumed through the diet disrupt B cell lipid raft clustering.     

Current treatment options for colon cancer peritoneal carcinomatosis

Peritoneal carcinomatosis (PC), the dissemination of cancer cells throughout the lining of the abdominal cavity, is the second most common presentation of colon cancer distant metastasis. Despite remarkable advances in cytotoxic chemotherapy and targeted therapy for colon cancer over the last 15 years, it has been repeatedly shown that these therapies remain ineffective for colon cancer PC. Recently, there has been a rapid accumulation of reports that cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) prolongs the life of colon cancer PC patients. Here, we will review the clinical presentation, the mechanisms of disease progression, and current treatment options for colon cancer PC, with a focus on the benefits and limitations of CRS-HIPEC.     

Non-rheumatic annular mitral stenosis: prevalence and characteristics

Aims: To define the prevalence and characteristics of non-rheumaticannular mitral stenosis (AMS) in a general population as comparedwith rheumatic mitral stenosis (RMS). Methods and results: Clinical and echocardiographical variables were assessed in70 patients with mitral stenosis. AMS and RMS patients wereage- and gender-matched for the comparison of echocardiographicvariables. Thirteen patients (18.5%) had AMS. Arterial hypertensionand hypercholesterolemia were more prevalent in AMS (77 vs.36% and 75 vs. 27%, respectively, P < 0.05). Mitral annuluscalcification severity score (2.2 vs. 1.3, P < 0.05) andleft ventricular mass (276 ± 73 vs. 209 ± 57 g,P < 0.05) were significantly higher in AMS. Mitral valvearea (MVA) was higher and mean gradient was lower (2.25 ±0.6 vs.1.9 ± 0.6 cm², 4 ± 1.2 vs. 5.6 ±3.5 mmHg, P = ns) in AMS. Pressure half-time (PHT) MVA and planimetryMVA had a better correlation in RMS than in AMS patients (r= 0.98 vs. 0.71, P < 0.05). Conclusion: AMS is more frequent than that is assumed and is associatedwith risk factors for coronary artery disease. AMS is generallymild and PHT may be less accurate for MVA calculation than inRMS.     

Malnutrition and liver disease in a developing country

Malnutrition is a highly prevalent and under recognized condition in developing countries of South Asia. The presence of malnutrition causes a severe impact on patients with liver cirrhosis. The etiology of cirrhosis differs in the South Asian region compared to the West, with hepatitis B and C still being the leading causes and the prevalence of nonalcoholic fatty liver disease increasing over time. Comorbid malnutrition worsens outcomes for cirrhosis patients. Urgent attention to address malnutrition is needed to improve patient outcomes. The etiology and pathophysiology of malnutrition in liver diseases is multifactorial, as reduction in liver function affects both macronutrients and micronutrients. A need for nutritional status assessment for liver disease patients exists in all parts of the world. There are many widely studied tools in use to perform a thorough nutritional assessment, of which some tools are low cost and do not require extensive training. These tools can be studied and evaluated for use in the resource limited setting of a country like Pakistan. Treatment guidelines for proper nutrition maintenance in chronic liver disease exist for all parts of the world, but the knowledge and practice of nutritional counseling in Pakistan is poor, both amongst patients and physicians. Emphasis on assessment for nutritional status at the initial visit with recording of vital signs is needed. Simultaneously, treating physicians need to be made aware of the misconceptions surrounding nutritional restrictions in cirrhosis so that patient education is done correctly based on proper scientific evidence.     

Patterns of youth tobacco and polytobacco usage: The shift to alternative tobacco products

Background: Despite significant declines in youth cigarette smoking, overall tobacco usage remains over 20% as non-cigarette tobacco product usage is increasingly common and polytobacco use (using 1+ tobacco product) remains steady. Objectives: The present study was designed to identify patterns of youth tobacco use and examine associations with sociodemographic characteristics and tobacco dependence. Methods: The current analysis uses Latent Class Analysis (LCA) to examine the 6,958 tobacco users (n = 2,738 female) in the National Youth Tobacco Survey (2012 and 2013). We used as indicators past month use of tobacco products (cigarettes, cigars, smokeless tobacco, e-cigarettes, hookah, snus, pipes, bidis, and kreteks) and regressed resulting classes on sociodemographic characteristics and tobacco dependence. Results: Nine classes emerged: cigarette smokers (33.4% of sample, also included small probabilities for use of cigars and e-cigarettes), cigar smokers (16.8%, nearly exclusive), smokeless tobacco users (12.3%, also included small probabilities for cigarettes, cigars, snus), hookah smokers (11.8%), tobacco smokers/chewers (10.7%, variety of primarily traditional tobacco products), tobacco/hookah smokers (7.2%), tobacco/snus/e-cig users (3.3%), e-cigarette users (2.9%,), and polytobacco users (1.7%, high probabilities for all products). Compared to cigarette smokers, tobacco/hookah smokers and hookah smokers were more likely to report Hispanic ethnicity. Polytobacco users were more likely to report dependence (AOR:2.77, 95% CI:[1.49–5.18]), whereas e-cigarette users were less likely (AOR:0.49, 95% CI:[0.24–0.97]).Conclusion: Findings are consistent with other research demonstrating shifts in adolescent tobacco product usage towards non-cigarette tobacco products. Continuous monitoring of these patterns is needed to help predict if this shift will ultimately result in improved public health.     

Breast Cancer in Pakistan a Critical Appraisal of the Situation Regarding Female Health and Where the Nation Stands

Breast cancer (BC) is the most common malignancy of women worldwide. In the past it was considered as disease of older middle aged women, but the incidence of BC in young females is growing in recent years concordant with studies in Pakistan. In this paper, we reviewed the mutant functions of tumor suppressor genes (BRCA1, BRCA2, p53, ATM and PTEN), epigenetic transformation and involvement of estrogen receptors in development of breast cancer. We further reviewed the current situation of BC in Pakistan that depicts a higher incidence in young females. According to SKMCH and RC data, age group 4549 years is more prone to BC with high rate of incidence 45.42%. A few studies explored the high expression of ER, PR and HER2/neu in Pakistani females. Moreover, presence of BRCA1 (c.1961dupA) mutation in Pakistani shows concordance with data in different areas of world. But we are unable to find an authentic study that can explore epigenetic based transformation of breast tumors in Pakistan. This area of research needs more attention to explore the complete picture of BC in Pakistan.     

Re-irradiation for head and neck squamous cell carcinoma

Introduction

Local recurrences after curative treatment have a potential for cure with salvage surgery or with re-irradiation.

Pulmonary telemedicine--a model to access the subspecialist services in underserved rural areas

Background

To describe the use of videoconference telemedicine for providing outpatient pulmonary consultation to a remote, underserved clinic site.

Methods

Analysis of data from the Milwaukee Veteran Affairs Medical Center (VAMC) pulmonary telemedicine clinic. Pulmonary physicians at the Milwaukee VAMC provide outpatient consultations with the use of videoconference technology to patients located at the Iron Mountain VAMC in Iron Mountain, MI (346 km or 215 miles from Milwaukee). Data on demographics, referral patterns, access to care, consultation process, and outcomes are presented.

Results

A total of 314 patients (684 visits) received telemedicine consultations between January 1, 1998 and December 31, 2004. Common reasons for referral were abnormal radiology (38%), chronic obstructive pulmonary disease (COPD) (26%), and dyspnea (13%). Physical exam was performed by the telemedicine registered nurse or respiratory therapists in 90% of visits. Common diagnoses were COPD (29%), benign pulmonary nodule (11%), bronchial asthma (6%), and lung cancer (6%). Telemedicine consultation resulted in a change in management for 41% of patients. Only 8% of patients required an in-person clinic visit at Milwaukee VAMC following a telemedicine visit. Telemedicine saved patients 473,340 km or 294,120 miles of travel over the study period.

Conclusions

The provision of subspecialty services using telemedicine to a remote underserved rural population provides improved patient access to subspecialty care. Physicians are able to rely on medical history and radiology to manage patients across a broad spectrum of complex pulmonary conditions with the assistance of a non-physician health care provider at the remote site.     

Activin-Like Kinase 5 (ALK5) Mediates Abnormal Proliferation of Vascular Smooth Muscle Cells from Patients with Familial Pulmonary Arterial Hypertension and Is Involved in the Progression of Experimental Pulmonary Arterial Hypertension Induced by Monocrotaline

Mutations in the gene for the transforming growth factor (TGF)-β superfamily receptor, bone morphogenetic protein receptor II, underlie heritable forms of pulmonary arterial hypertension (PAH). Aberrant signaling via TGF-β receptor I/activin receptor-like kinase 5 may be important for both the development and progression of PAH. We investigated the therapeutic potential of a well-characterized and potent activin receptor-like kinase 5 inhibitor, SB525334 [6-(2-tert-butyl-5-{6-methyl-pyridin-2-yl}-1H-imidazol-4-yl)-quinoxaline] for the treatment of PAH. In this study, we demonstrate that pulmonary artery smooth muscle cells from patients with familial forms of idiopathic PAH exhibit heightened sensitivity to TGF-β1 in vitro, which can be attenuated after the administration of SB525334. We further demonstrate that SB525334 significantly reverses pulmonary arterial pressure and inhibits right ventricular hypertrophy in a rat model of PAH. Immunohistochemical studies confirmed a significant reduction in pulmonary arteriole muscularization induced by monocrotaline (used experimentally to induce PAH) after treatment of rats with SB525334. Collectively, these data are consistent with a role for the activin receptor-like kinase 5 in the progression of idiopathic PAH and imply that strategies to inhibit activin receptor-like kinase 5 signaling may have therapeutic benefit.Pulmonary arterial hypertension (PAH) is a severe disease of the small pulmonary arteries characterized by vascular damage and narrowing of the vessels, leading to raised pulmonary artery pressure, right ventricular (RV) hypertrophy, and ultimately, right-sided heart failure and death. The combined effects of vasoconstriction, remodeling of the pulmonary vessel wall comprising abnormal endothelial and pulmonary artery smooth muscle cell (PASMC) proliferation and apoptosis, enhanced extracellular matrix deposition, and elevated thrombosis contribute to increased pulmonary vascular resistance and the resultant right-sided cardiac hypertrophy and mortality.¹ Although the exact molecular basis underlying the vascular damage remains unclear, genetic studies have linked germ-line mutations in a gene encoding the transforming growth factor β (TGF-β) superfamily receptor member bone morphogenetic protein receptor 2 (BMPR-II) to the development of heritable forms of idiopathic pulmonary arterial hypertension (iPAH), encompassing familial and a proportion of sporadic cases of the disease.²Studies to assess the consequences of loss of BMPR-II have been undertaken to help elucidate the functional role of this receptor in the human pathology. Data from in vitro studies have shown that TGF-β addition to PASMCs isolated from patients with iPAH results in an elevated proliferative response compared with the effects mediated by addition of this growth factor to PASMCs from normotensive individuals.³ These data suggest that BMPR-II may repress the activity of the TGF-β/activin-like kinase 5 (ALK5) pathway in PASMCs from healthy individuals and that loss of BMPR-II may lead to unregulated TGF-β/ALK5 activity in PASMCs from patients with iPAH. Indeed, elevated Smad2 phosphorylation, a marker of TGF-β/ALK5 activity, can also be observed in endothelial cells isolated from plexiform lesions of patients with iPAH indicative of pathway activation.⁴ Furthermore, analysis of the expression levels of TGF-β1, ALK5 and transforming growth factor-β receptor II (TGF-βRII) in leukocytes from patients with iPAH also reveals that the ratio of ALK5 expression to TGF-βRII is significantly higher in iPAH patients compared with normal controls, pointing toward an imbalance in expression patterns of components of the TGF-β pathway in circulating immune cells.⁵ Taken together, this evidence suggests that abnormal TGF-β/ALK5 signaling may be important in mediating the development and progression of iPAH.Evidence has accumulated that highlights an important role for TGF-β signaling in the development and progression of certain pathophysiological features observed in preclinical models of experimental PAH. For instance, elevated expression levels of TGF-β ligands have been reported in the rat monocrotaline (MCT)⁶ and hypoxia models.⁷ In addition, altered expression of TGF-β ligands and type I receptors have been described in the pulmonary vasculature of a lamb model of congenital heart disease after aortopulmonary vascular graft.⁸ Studies addressing the functional role of TGF-β signaling in preclinical rodent models of PAH have recently been reported. Transgenic mice engineered to express an inducible kinase-deficient TGF-βRII receptor appear to be refractory to PAH induced by low oxygen suggesting that intact TGF-β is required for induction of PAH by hypoxia.⁹ Controversy exists to the role played by TGF-β signaling in MCT-mediated PAH in rats. A study by Zakrzewicz and colleagues¹⁰ demonstrated that components of the TGF-β signaling pathway are down-regulated in rats after MCT treatment, whereas a more recent study has shown elevated TGF-β pathway activation in pulmonary vascular cells of MCT-treated rats.¹¹ Interestingly, the latter study also demonstrated the ALK5 inhibitor, SD-208 prevented the development of MCT-induced PAH in rats. In contrast, delaying administration of SD-208 until established PAH had occurred resulted in a less pronounced impact on the ensuing pathologies, leading the authors to conclude that TGF-β/ALK5 signaling may play an important role in the initiation of experimental PAH, but a limited role in progression of established disease. These data would naturally imply that strategies to inhibit ALK5 signaling in iPAH may have limited therapeutic benefit because patients will usually present at later stages of the disease.This study proposed to determine the validity of targeting the TGF-β pathway via a selective ALK5 inhibitor, SB525334. Here we demonstrate enhanced sensitivity to TGF-β in cells isolated from patients with familial iPAH, compared with normotensive controls, as shown by significantly higher expression levels of several TGF-β-regulated genes. We also show that abnormal TGF-β-mediated proliferation of PASMCs from patients with familial iPAH in vitro can be inhibited by the ALK5-selective compound, SB525334 with IC₅₀ values consistent with ALK5 inhibition. We have also tested the efficacy of SB525334 in reversing established PAH in the MCT rat model of disease. In contrast to the study using SD-208,¹¹ we demonstrate significant reversal of elevated mean pulmonary arterial pressure and inhibition of RV hypertrophy after MCT treatment using standard invasive readouts (right heart catheterization and Fulton index determination) or via noninvasive small animal echocardiography after oral administration of SB525334. Our computerized lung morphometry data suggest that small pulmonary artery remodeling induced after MCT insult is reversed by addition of SB525334 to rats and accounts for the significant improvement in hemodynamics after compound treatment. Our data support a role for ALK5 signaling in the latter stages of experimental PAH and implies that significant therapeutic benefit may be attained in the human pathology after systemic inhibition of the pathway.