Comparison of academic productivity and funding support between United States and international medical graduate vascular surgeons.

OBJECTIVE: The demand for vascular surgeons in the United States stands to far exceed the current supply. International medical graduates (IMGs) are not only vital to meeting the country's growing health care needs, but also help to advance clinical research and medical education in the field of vascular surgery. Nearly 17% of practicing vascular surgeons in the United States are IMGs, yet little is known about their relative contributions to academic vascular surgery. Our study aims to compare the academic profiles and funding support for IMG vascular surgeons to that of their US medical graduate (USMG) counterparts. METHODS: A cross-sectional study was performed on all IMG and USMG academic vascular surgeons practicing in US-based hospitals with vascular surgery residency and/or fellowship programs. In addition to the baseline surgeon characteristics, academic profiles and research output were also collected. Furthermore, the National Institutes of Health (NIH) research reporting tool and open payments database were queried for any funding/payments to surgeons in both groups. Matching for year of vascular surgery training program graduation was performed where appropriate. RESULTS: A total of 908 academic vascular surgeons were included; 759 (83.6%) were USMGs and 149 (16.4%) were IMGs. The median year of graduation was comparable between the two groups, but USMGs had a significantly higher proportion of female surgeons (23.6% vs 10.7%; P = .0003). There were no significant differences in the academic profiles and leadership positions between the two groups. Although research productivity is similar between the two groups, IMG surgeons were more likely to have first or senior-authorship papers (47.1% vs 37.5%; P < .001). Additionally, faculty departments chaired/cheifed by a USMG were less likely to be staffed with IMG vascular surgeons (1.6 surgeons vs 3.1 surgeons; P < .0001). Following grant analysis, USMG surgeons received more NIH R01 grants (5.7% vs 1.3%; P = .026). R01-funded surgeons had significantly greater research output by number of publications (121.0 vs 47.5), citations (3872 vs 938), H-index (32.0 vs 17.5), and average journal impact factor (>10: 86.7% vs 33.3%) (all P < .001). CONCLUSIONS: The efforts to further diversify vascular surgery are vital to better serving an increasingly diverse US population, amid growing disparities in health care. Although IMGs account for a minority of academic vascular surgeons, and contribute significantly to their published research, they had less NIH R01 funding, warranting further investigation.

Median Arcuate Ligament Syndrome: Comparing the Safety of Open and Laparoscopic Management in a Large Cohort.

BACKGROUND: Open surgery has been the traditional approach for Median Arcuate Ligament Syndrome (MALS) management. However, there has been a recent rise in laparoscopic management for MALS. In this study we used a large-scale database to compare perioperative complications between open and laparoscopic approaches for MALS. METHODS: Using the National Inpatient Sampling database, we identified all patients surgically treated for MALS between 2008 and 2018 through conventional open and laparoscopic approaches. International Classification of Diseases (ICD)-9 and ICD-10 codes were used to identify patients and their specific surgical interventions. Statistical analyses were conducted to compare the perioperative complications between the 2 MALS surgical approaches, as well as and length of hospital stays and total charges. The complications include postoperative bleeding, accidental operative laceration/puncture, surgical wound infection, ileus, hemothorax/pneumothorax, and cardiac and respiratory complications. RESULTS: A total of 630 patients were identified: 487 (77.3%) patients underwent open surgery while 143 (22.7%) patients underwent laparoscopic decompression. The majority of the study population consisted of female patients (74.8%) with a mean age of 40.6 ± 19 years. Patients who underwent laparoscopic decompression had significantly less all-cause perioperative complications compared to their open surgery counterparts (0.7% vs. 9.9%; P = 0.001). Additionally, prolonged hospitalization was noted in the open group compared to the laparoscopic 1 (5.8 days vs. 3.5; P < 0.001, respectively) with a significantly higher mean of total hospital charges ($70,095.8 vs. 56,113.5; P = 0.016). CONCLUSIONS: Laparoscopic management of MALS has significantly less perioperative complications than open surgical decompression with shorter hospitalization and lower total charges. Given that, laparoscopic technique could be a safe option in treating select MALS patients.

Peripheral artery disease and extracorporeal membrane oxygenation: Examining a high-risk cohort over time.

OBJECTIVE: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a resource-intensive approach for the management of refractory cardiogenic shock. Within this population exists a substantial cohort of patients with peripheral artery disease (PAD), which independently increases the risk of complications and all-cause mortality. We studied 10-year national trends of the impact of PAD among VA-ECMO recipients to better understand the prevalence of PAD and implications on outcomes in this vulnerable population. METHODS: This 10-year retrospective, propensity score-matched study identified all adult patients (≥18) who underwent VA-ECMO between 2009 and 2018, from a large US database (National Inpatient Sample). Patients with an ICD diagnosis of PAD were identified. The primary endpoints of in-hospital mortality, bleeding complications and major limb loss (above- or below-knee amputation) were compared between patients with PAD to those without. RESULTS: A total of 6768 patients were identified, of which 342 (5.3%) had PAD. The median age at admission was significantly higher in PAD patients [64 years vs. 55 years; p < .01], as was male gender [71% vs. 64%; p < .01]. Patients with PAD had higher rates of smoking (38.9% vs. 23.3%), hypertension (71.1% vs. 50%), diabetes (37.4% vs. 27.0%), chronic kidney disease (30.1% vs. 18.0%), coronary artery disease (76.0% vs. 35.0%) and dyslipidemia (76.0% vs. 35.0); all p < .01. After propensity-matching 2:1 for comorbidities, PAD patients were found to have significantly greater overall complications, including in-hospital mortality, bleeding, surgical wound infections, pseudoaneurysms, and major adverse limb events [71.9% vs. 63.9%; p < .01]. Subgroup analysis revealed greater in-hospital mortality [62.2% vs. 55.3%; p < .05], major amputations [4.1% vs. 0.3%; p < .01] and blood transfusions [32.2% vs. 26.2%; p < .05] in PAD patients. Over 2014-2018, the non-PAD group demonstrated statistically discernable trends in a 51.1% decrease in overall complications and a 28.1% increase in survival to discharge (all p < .01). Over the same time period the PAD cohort experienced a modest, nonsignificant, decrease in complications [7.0%, p = .40] and a decrease in those surviving to discharge [47.1% vs. 40.5%, p = .91]. CONCLUSION: Patients with PAD on VA-ECMO are sicker at baseline and experience significantly greater major amputations and higher in-hospital mortality. They have not benefitted from the considerable decrease in complication rates and increase in survival to discharge over time as compared to their non-PAD counterparts. These findings demonstrate the substantial frailty of the PAD population within an already high-risk cohort, and highlight the need for better procedural approaches and innovative technologies.

The effects of major depression disorder on neurogenic thoracic outlet syndrome surgery outcomes.

OBJECTIVES: Thoracic outlet syndrome (TOS) is a group of disorders caused by impingement of the neurovascular structures at the thoracic outlet. Neurogenic TOS (nTOS), which is thought to be caused by a compression of the brachial plexus, accounts for more than 90% of the cases. Although treatment for nTOS is successful through physiotherapy and/or surgical decompression, little is known about the impact of psychosocial factors, namely, major depressive disorder (MDD), on postoperative outcomes such as non-routine discharge (NRD). Here, we assess whether MDD predicts the type of discharge following nTOS surgical intervention. METHODS: A retrospective analysis of the National Inpatient Sample database from the years 2005-2018 was performed. Using the International Classification of Diseases Clinical Modification, Ninth and Tenth revisions, patients who underwent a surgical intervention for nTOS were identified. Our primary outcome was to investigate the effects of MDD on nTOS patient disposition status after surgical management; secondary outcomes included analysis of total hospital charges and length of stay. NRD was defined as anything beyond discharge home without healthcare services. Univariate and multivariable logistic regression analyses were conducted to assess MDD and other potential independent predictors of NRD and prolonged hospital stay (> 2 days) following surgical intervention. RESULTS: A total of 6099 patients were identified: 596 (9.77%) patients with MDD and 5503 (90.23%) without MDD. On average, patients with MDD were older (39.6 ± 12.0 years vs. 36.0 ± 13.0 years; p < 0.001), female (80.7% vs. 63.5%; p < 0.001), white (89.6% vs. 85.6%; p = 0.030), and on Medicare (9.6% vs 5.2%; p < 0.001). Univariate and multivariable logistic regression models identified MDD as an independent risk factor associated with a higher risk of NRD (adjusted odds ratio [aOR], 1.50; 95% confidence interval [CI], 1.0-2.2). Additionally, chronic kidney disease (aOR, 2.60; 95% CI, 1.2-5.4), postoperative complications (aOR, 1.87; 95% CI, 1.2-2.9), and Medicare (aOR, 2.95; 95% CI, 1.9-4.7) were statistically significant predictors for higher risk of NRD. However, MDD was not associated with prolonged hospital stay (aOR, 1.00; 95% CI, 0.8-1.2) or higher median of total charges (MDD group: $27,867 vs. non-MDD group: $28,123; p = 0.799). CONCLUSION: Comorbid MDD was strongly associated with higher NRD rates following nTOS surgical intervention. MDD had no significant impact on length of hospital stay or total hospital charges. Additional prospective research is necessary in order to better evaluate the impact of MDD in patients with nTOS.

The Methylcitrate Cycle and Its Crosstalk with the Glyoxylate Cycle and Tricarboxylic Acid Cycle in Pathogenic Fungi.

In fungi, the methylcitrate cycle converts cytotoxic propionyl-coenzyme A (CoA) to pyruvate, which enters gluconeogenesis. The glyoxylate cycle converts acetyl-CoA to succinate, which enters gluconeogenesis. The tricarboxylic acid cycle is a central carbon metabolic pathway that connects the methylcitrate cycle, the glyoxylate cycle, and other metabolisms for lipids, carbohydrates, and amino acids. Fungal citrate synthase and 2-methylcitrate synthase as well as isocitrate lyase and 2-methylisocitrate lyase, each evolved from a common ancestral protein. Impairment of the methylcitrate cycle leads to the accumulation of toxic intermediates such as propionyl-CoA, 2-methylcitrate, and 2-methylisocitrate in fungal cells, which in turn inhibits the activity of many enzymes such as dehydrogenases and remodels cellular carbon metabolic processes. The methylcitrate cycle and the glyoxylate cycle synergistically regulate carbon source utilization as well as fungal growth, development, and pathogenic process in pathogenic fungi.

Prevalence of abdominal aortic aneurysms in patients with lung cancer.

OBJECTIVE: Concomitance of abdominal aortic aneurysm (AAA) and primary lung cancer (LC) is not uncommon due to several shared risk factors. To evaluate the incidence of this association, analysis of the National Inpatient Sample database was utilized. METHODS: A retrospective analysis of the National Inpatient Sample database between 2014 and 2018 for all patients diagnosed with primary LC was performed. The differences in the reported findings between the LC and control groups were assessed using the Pearson χ2, Fisher exact, Student t, and/or Mann-Whitney U tests where appropriate. Multivariable logistic regression analysis was conducted to determine independent predictors of the presence of documented AAA. RESULTS: A total of 158,904 patients were identified. Of these, 2430 patients (1.53%) were diagnosed with AAA and 156,474 (98.47%) without AAA. In the multivariable model, LC patients had higher odds of AAA compared with the general population (odds ratio, 1.43; 95% confidence interval, 1.35-1.51). In all age groups, female smokers had a higher rate of AAA compared with female nonsmokers (age <60 years, 0.13% vs 0.04%; 60-69 years, 0.77% vs 0.34%; 70-79 years, 1.65% vs 0.69%; and >80 years, 2.63% vs 1.31%; all P < .001). CONCLUSIONS: LC and AAA share similar risk factors, which may explain the higher AAA prevalence among patients with LC. Given the higher prevalence of AAA in smokers compared with nonsmokers across all age groups in both male and female patients with LC, further sex-based studies investigating the overall mortality and morbidity benefits of AAA screening among patients with LC are highly warranted. This consideration would potentially address the sex disparity in outcomes for AAA management.

Outcomes of Infrainguinal Bypass in Patients with Cannabis vs Opioid Use Disorder.

BACKGROUND: Marijuana and opioids are commonly used illicit drugs in the United States and their use continues to rise. Cannabis use disorder (CUD) and Opioid use disorder (OUD) are associated with adverse effects on public health and postoperative outcomes. However, their impact on vascular surgery, specifically infrainguinal bypass repair (IIB). is not well described in the literature. Therefore, our study aimed to assess perioperative outcomes in patients with CUD and OUD who underwent IIB. METHODS: A retrospective analysis of the National Inpatient Sample database for the years 2005 to 2018 was performed. Using the International Classification of Diseases Clinical Modification, Ninth and Tenth revisions, patients who were diagnosed with peripheral artery disease and underwent IIB repair.were identified. Our primary outcome was the comparison of rates of in-hospital complications between the groups, and the secondary outcomes included analysis of total hospital charges and length of stay. A 1:1 propensity score matching (PSM) CUD and OUD patients to their control groups without the disease was conducted using the nearest-neighbor method. The matching was based on select patient demographics and comorbidities included in our analyses. RESULTS: A total of 190,794 patients were identified: 972 patients with CUD and 682 patients with OUD. In the matched cohorts, patients with a diagnosis of CUD had a higher incidence of in-hospital cardiac complications (adjusted Odds Ratio [aOR], 1.76; 95% Confidence Interval [CI], 0.99-3.12) and acute kidney injury (AKI) (aOR, 1.51; CI, 1.09-2.08). Additionally, total hospital charges and mean length of stay were higher in the CUD group (P < 0.001). Those with OUD had a higher incidence of postoperative respiratory complications (aOR, 1.92; CI, 1.23-2.99), sepsis (aOR, 2.39; CI, 1.32-4.34), infection (aOR, 3.55; CI, 1.16-10.84), AKI (aOR, 2.11; CI,1.47-3.04), major amputations (aOR, 1.69; CI, 1.07-2.69), along with higher total charges and mean length of stay (P < 0.001). CONCLUSIONS: Both CUD and OUD have increased incidence of postoperative complications following IIB. The OUD group had generally worse outcomes compared to patients with CUD. Both were associated with a substantial increase in total hospital charges and length of hospital stay. A further prospective study is warranted to provide better insight on the effects of substance use disorders on the procedure's short- and long-term outcomes.

An acute gastroenteritis outbreak associated with a contaminated water supply system, Turkey, 2018.

Disruption of routine monitorization and chlorination of the water supply system during a week-long holiday led to a multi-organism gastroenteritis outbreak in a district with limited laboratory support. More than a 10-fold increase in patients with gastroenteritis was reported. Enteropathogenic Escherichia coli, Enteroaggregative E. coli, and norovirus were detected in human specimen samples. The main water tank and pipes were rusted; 13 out of the 19 water samples tested positive for total Coliform (1-920 colony-forming units (CFU)/100 ml) and E. coli (1-720 CFU/100 ml). Chlorine levels were below 0.2 ppm in seven of the nine samples. Information of 1,815 cases was obtained from the hospital records with a crude attack rate of 2.9%. Cases widespread in the district increased throughout the holiday, epidemic curve revealed a point-source outbreak. The case-control study revealed that consumption of drinking tap water and using it to clean vegetables/fruits were significantly associated with the illness. While drinking only bottled water had a protective effect against the illness. The culture technique showed that the water supply samples were positive for pathogenic bacteria. Upon decision in a multi-stakeholder meeting, the water tank was cleaned, and the Municipality initiated the renovation of the water supply system.

The Physiological Function and Potential Role of the Ubiquitous Na+/H+ Exchanger Isoform 8 (NHE8): An Overview Data.

The Na+/H+ exchanger transporters (NHE) play an important role in various biologic processes including Na+ absorption, intracellular pH homeostasis, cell volume regulation, proliferation, and apoptosis. The wide expression pattern and cellular localization of NHEs make these proteins pivotal players in virtually all human tissues and organs. In addition, recent studies suggest that NHEs may be one of the primeval transport protein forms in the history of life. Among the different isoforms, the most well-characterized NHEs are the Na+/H+ exchanger isoform 1 (NHE1) and Na+/H+ exchanger isoform 3 (NHE3). However, Na+/H+ exchanger isoform 8 (NHE8) has been receiving attention based on its recent discoveries in the gastrointestinal tract. In this review, we will discuss what is known about the physiological function and potential role of NHE8 in the main organ systems, including useful overviews that could inspire new studies on this multifaceted protein.

Knowledge, attitudes and practices towards deceased organ donation among parents of children with End Stage Kidney Disease.

OBJECTIVE: To assess the knowledge, attitudes, and practices (KAP) towards deceased organ donation (DOD) of the parents/ guardians of children with end stage kidney disease (ESKD). METHODS: This cross sectional survey was conducted between April and December 2020. A structured questionnaire was filled to assess the sociodemographic information, knowledge, attitude, and practice about DOD. RESULTS: A total of 130 participants with a mean age of 37±7 years were included in the study. Among all, 66 (50.8%) claimed that they had prior knowledge about DOD. However, on further questioning, no one knew who can be the deceased organ donor. Their responses about registration place and permission from religion were positive in 24(36.4%) and 31(47.0%) cases respectively. Regarding attitude, positive responses to willingness to get registered and discussing DOD in social circle were given by 37(56.1%) and 21 (31.8%) participants respectively. Only one participant was registered as donor. The remaining 64(49.2%) participants who had no prior knowledge were given relevant information and were interviewed after one week. Only 24(37.5%) showed willingness to get registered as donors and 06 (9.4%) participants discussed the topic of DOD in their social circle. CONCLUSIONS: The results showed that the knowledge, attitudes, and practices of people who are most desperate for transplantation of their children were poor and did not change significantly even after providing them relevant information.

Impact of Cardiac Cycle on Thoracic Aortic Geometry-Morphometric Analysis of Ecg Gated Computed Tomography.

BACKGROUND: Understanding morphological changes of ascending aorta, aortic arch and descending aorta with cardiac and respiratory motion is critical for planning of endovascular repair of thoracic aorta. The aim of this study was to determine the impact of the cardiac cycle on thoracic aortic geometry. METHODS: In this retrospective study, electrocardiogram-gated cardiac computed tomography from 116 patients who were evaluated for transcatheter aortic valve replacement were reviewed. A protocol for measurements of maximal diameters and lengths of the thoracic aorta and supra-aortic vessels was established. Measurements were made in multiplanar views perpendicular to the semiautomatically created centerline on both systolic and diastolic phases. RESULTS: Mean age was 77 ± 11 years of our study cohort. Mean systolic and diastolic diameter were 31.6 ± 0.42 and 30.1 ± 4.4 mm at the sinotubular junction (STJ), 35.6 ± 4.8 and 34.8 ± 4.7 mm in the ascending aorta, 29.1 ± 3.3 and 28.5 ± 3.3 mm in the aortic arch (distal left common carotid artery), and 26.7 ± 5.4 and 25.8 ± 5.4 mm in the descending aorta. Mean diameter change was 1.5 ± 0.9 mm at the STJ, 0.8 ± 0.9 mm in the ascending aorta, 0.6 ± 0.8 mm in the aortic arch, and 0.9 ± 1.2 mm in the descending aorta. Mean arterial strain was 5.0 ± 3.2% at the level of the STJ, 2.4 ± 2.7% in the ascending aorta, 2.0 ± 2.9% in the aortic arch, and 3.9 ± 5.7% in the descending aorta. CONCLUSIONS: Our results demonstrated that small but significant circumferential and longitudinal strain was present at every aortic level. These findings may have implications for endovascular thoracic aortic repair and may provide reference values for future comparison.

Zinc ameliorates intestinal barrier dysfunctions in shigellosis by reinstating claudin-2 and -4 on the membranes.

Whether zinc (Zn2+) regulates barrier functions by modulating tight-junction (TJ) proteins when pathogens such as Shigella alter epithelial permeability is still unresolved. We investigated the potential benefits of Zn2+ in restoring impaired barrier function in vivo in Shigella-infected mouse tissue and in vitro in T84 cell monolayers. Basolateral Shigella infection triggered a time-dependent decrease in transepithelial resistance followed by an increase in paracellular permeability of FITC-labeled dextran and altered ion selectivity. This led to ion and water loss into the intestinal lumen. Immunofluorescence studies revealed redistribution of claudin-2 and -4 to an intracellular location and accumulation of these proteins in the cytoplasm following infection. Zn2+ ameliorated this perturbed barrier by redistribution of claudin-2 and -4 back to the plasma membrane and by modulating the phosphorylation state of TJ proteins t hough extracellular signal-regulated kinase (ERK)1/2 dependency. Zn2+ prevents elevation of IL-6 and IL-8. Mice challenged with Shigella showed that oral Zn2+supplementation diminished diverse pathophysiological symptoms of shigellosis. Claudin-2 and -4 were susceptible to Shigella infection, resulting in altered barrier function and increased levels of IL-6 and IL-8. Zn2+ supplementation ameliorated this barrier dysfunction, and the inflammatory response involving ERK-mediated change of phosphorylation status for claudin-2 and -4. Thus, Zn2+ may have potential therapeutic value in inflammatory diarrhea and shigellosis. NEW & NOTEWORTHY Our study addresses whether Zn2+ could be an alternative strategy to reduce Shigella-induced inflammatory response and epithelial barrier dysfunction. We have defined a mechanism in terms of intracellular signaling pathways and tight-junction protein expression by Zn2+. Claudin-2 and -4 are susceptible to Shigella infection, whereas in the presence of Zn2+ they are resistant to infection-related barrier dysfunction involving ERK-mediated change of phosphorylation status of claudins.

Short-term outcome of clinical and histopathologic variants of mesangiocapillary glomerulonephritis in children: A retrospective analysis from a tertiary care center.

OBJECTIVE: To study the frequency, clinicopathological features and short-term outcome of mesangiocapillary glomerulonephritis (MCGN) in children at a tertiary care kidney center in Pakistan. METHODS: A descriptive, observational study was conducted at the Paediatric Nephrology Department, Sindh Institute of Urology and Transplantation, Karachi, from January 2011 till December 2015. A review of all paediatric (<18 years) renal biopsies during the study period was performed and cases of MCGN were enrolled. The clinical presentation, laboratory findings, histology and outcome were analyzed. RESULTS: During the study period, 890 paediatric renal biopsies were performed. Of these, 63(7%) were MCGN. Among these, 34(54%) were males and 29 (46%) females. Mean age was 9.9 ± 3.2years. Thirty four (54%) presented with nephrotic syndrome (NS), and29 (46%) with rapidly progressive glomerulonephritis (RPGN).Mean duration of follow-up was 1.66 ± 1.34 years. Outcome of patients with NS with renal failure (RF)was complete remission (CR) in 1(7.7%), persistent proteinuria with normal renal functions in 1(7.7%),chronic kidney disease (CKD) in 3 (23%), end-stage renal disease (ESRD) in 4 (30.8%), while 4 (30.8%) children died, while in children with NS and normal renal functions, CR was obtained in 3(14.2%), partial remission (PR) in 10(47.6%),CKD in 4(19%), and ESRD in 3 (14.3%).Outcome of cases presenting as RPGN was CR in 13 (44.8%), CKD in 2(6.9%) and ESRD in 7(24.1%) cases. Four children (13.8%) were lost to follow-up, while 3(10.3%) died. CONCLUSIONS: Children with MCGN presenting clinically with NS with impaired renal functions have worst outcome.

Anoctamin 6 Contributes to Cl- Secretion in Accessory Cholera Enterotoxin (Ace)-stimulated Diarrhea: AN ESSENTIAL ROLE FOR PHOSPHATIDYLINOSITOL 4,5-BISPHOSPHATE (PIP2) SIGNALING IN CHOLERA.

Accessory cholera enterotoxin (Ace) of Vibrio cholerae has been shown to contribute to diarrhea. However, the signaling mechanism and specific type of Cl- channel activated by Ace are still unknown. We have shown here that the recombinant Ace protein induced ICl of apical plasma membrane, which was inhibited by classical CaCC blockers. Surprisingly, an Ace-elicited rise of current was neither affected by ANO1 (TMEM16A)-specific inhibitor T16A(inh)-AO1(TAO1) nor by the cystic fibrosis transmembrane conductance regulator (CFTR) blocker, CFTR inh-172. Ace stimulated whole-cell current in Caco-2 cells. However, the apical ICl was attenuated by knockdown of ANO6 (TMEM16F). This impaired phenotype was restored by re-expression of ANO6 in Caco-2 cells. Whole-cell patch clamp recordings of ANO currents in HEK293 cells transiently expressing mouse ANO1-mCherry or ANO6-GFP confirmed that Ace induced Cl- secretion. Application of Ace produced ANO6 but not the ANO1 currents. Ace was not able to induce a [Ca2+]i rise in Caco-2 cells, but cellular abundance of phosphatidylinositol 4,5-bisphosphate (PIP2) increased. Identification of the PIP2-binding motif at the N-terminal sequence among human and mouse ANO6 variants along with binding of PIP2 directly to ANO6 in HEK293 cells indicate likely PIP2 regulation of ANO6. The biophysical and pharmacological properties of Ace stimulated Cl- current along with intestinal fluid accumulation, and binding of PIP2 to the proximal KR motif of channel proteins, whose mutagenesis correlates with altered binding of PIP2, is comparable with ANO6 stimulation. We conclude that ANO6 is predominantly expressed in intestinal epithelia, where it contributes secretory diarrhea by Ace stimulation in a calcium-independent mechanism of RhoA-ROCK-PIP2 signaling.

The antimicrobial activity of ZnO nanoparticles against Vibrio cholerae: Variation in response depends on biotype.

The potency of zinc oxide nanoparticles (NPs), with a core size of ~7-10nm, to inhibit cholera disease was investigated by demonstrating the effect on two biotypes (classical and El Tor) of O1 serogroup of Vibrio cholerae-El Tor was more susceptible both in planktonic and in biofilm forms. Interaction with ZnO NP results in deformed cellular architecture. Increased fluidity and depolarization of membrane, and protein leakage further confirmed the damages inflicted on Vibrio by NP. NP was shown to produce reactive oxygen species (ROS) and induce DNA damage. These results suggest that the antibacterial mechanism of ZnO action is most likely due to generation of ROS and disruption of bacterial membrane. The antimicrobial efficacy of NP has been validated in animal model. The synergistic action of NP and antibiotic suggests an alternative for the treatment of cholera.

Immobilization of α-amylase onto a calix[4]arene derivative: Evaluation of its enzymatic activity.

In order to enhance the cost-effectiveness practicability of enzymes in many industries such as pharmaceutical, food, medical and some other technological processes, there is great need to immobilize them onto a solid supports. In this study, a new and efficient immobilization of α-amylase from Saccharomyces cerevisiae has been developed by using the surface functionalization of calix[4]arene as support. A glutaraldehyde-containing amino group functionalized calix[4]arene was used to immobilize α-amylase covalently. In this procedure, imide bonds are formed between amino groups on the protein and aldehyde groups on the calix[4]arene surface. The surface modified support was characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM). The effect of various preparation conditions on the immobilized α-amylase process such as immobilization time, enzyme concentration, temperature and pH were investigated. The influence of pH and temperature on the activity of free and immobilized α-amylase was also studied using starch as substrate. The optimum reaction temperature and pH value for the enzymatic conversion catalyzed by the immobilized α-amylase were 25°C and 7, respectively. Compared to the free enzyme, the immobilized α-amylase retained 85% of its original activity and exhibited significant thermal stability than the free one and excellent durability.

The Epac1 signaling pathway regulates Cl- secretion via modulation of apical KCNN4c channels in diarrhea.

The apical membrane of intestinal epithelia expresses intermediate conductance K(+) channel (KCNN4), which provides the driving force for Cl(-) secretion. However, its role in diarrhea and regulation by Epac1 is unknown. Previously we have established that Epac1 upon binding of cAMP activates a PKA-independent mechanism of Cl(-) secretion via stimulation of Rap2-phospholipase Cε-[Ca(2+)]i signaling. Here we report that Epac1 regulates surface expression of KCNN4c channel through its downstream Rap1A-RhoA-Rho-associated kinase (ROCK) signaling pathway for sustained Cl(-) secretion. Depletion of Epac1 protein and apical addition of TRAM-34, a specific KCNN4 inhibitor, significantly abolished cAMP-stimulated Cl(-) secretion and apical K(+) conductance (IK(ap)) in T84WT cells. The current-voltage relationship of basolaterally permeabilized monolayers treated with Epac1 agonist 8-(4-chlorophenylthio)-2'-O- methyladenosine 3',5'-cyclic monophosphate showed the presence of an inwardly rectifying and TRAM-34-sensitive K(+) channel in T84WT cells that was absent in Epac1KDT84 cells. Reconstructed confocal images in Epac1KDT84 cells revealed redistribution of KCNN4c proteins into subapical intracellular compartment, and a biotinylation assay showed ∼83% lower surface expression of KCNN4c proteins compared with T84WT cells. Further investigation revealed that an Epac1 agonist activates Rap1 to facilitate IK(ap). Both RhoA inhibitor (GGTI298) and ROCK inhibitor (H1152) significantly reduced cAMP agonist-stimulated IK(ap), whereas the latter additionally reduced colocalization of KCNN4c with the apical membrane marker wheat germ agglutinin in T84WT cells. In vivo mouse ileal loop experiments showed reduced fluid accumulation by TRAM-34, GGTI298, or H1152 when injected together with cholera toxin into the loop. We conclude that Rap1A-dependent signaling of Epac1 involving RhoA-ROCK is an important regulator of intestinal fluid transport via modulation of apical KCNN4c channels, a finding with potential therapeutic value in diarrheal diseases.

ERK1/2 mediates lung adenocarcinoma cell proliferation and autophagy induced by apelin-13.

The aim of this study was to investigate the role of apelin in the cell proliferation and autophagy of lung adenocarcinoma. The over-expression of APJ in lung adenocarcinoma was detected by immunohistochemistry, while plasma apelin level in lung cancer patients was measured by enzyme-linked immunosorbent assay. Our findings revealed that apelin-13 significantly increased the phosphorylation of ERK1/2, the expression of cyclin D1, microtubule-associated protein 1 light chain 3A/B (LC3A/B), and beclin1, and confirmed that apelin-13 promoted A549 cell proliferation and induced A549 cell autophagy via ERK1/2 signaling. Moreover, there are pores on the surface of human lung adenocarcinoma cell line A549 and apelin-13 causes cell surface smooth and glossy as observed under atomic force microscopy. These results suggested that ERK1/2 signaling pathway mediates apelin-13-induced lung adenocarcinoma cell proliferation and autophagy. Under our experimental condition, autophagy associated with 3-methyladenine was not involved in cell proliferation.