Vadim Sherman

Class II Major Histocompatibility Complex Plays an Essential Role in Obesity-Induced Adipose Inflammation

Adipose-resident T cells (ARTs) regulate metabolic and inflammatory responses in obesity, but ART activation signals are poorly understood. Here, we describe class II major histocompatibility complex (MHCII) as an important component of high-fat-diet (HFD)-induced obesity. Microarray analysis of primary adipocytes revealed that multiple genes involved in MHCII antigen processing and presentation increased in obese women. In mice, adipocyte MHCII increased within 2 weeks on HFD, paralleling increases in proinflammatory ART markers and decreases in anti-inflammatory ART markers, and preceding adipose tissue macrophage (ATM) accumulation and proinflammatory M1 polarization. Mouse 3T3-L1 and primary adipocytes activated T cells in an antigen-specific, contact-dependent manner, indicating that adipocyte MHCII is functional. HFD-fed MHCII(-/-) mice developed less adipose inflammation and insulin resistance than did wild-type mice, despite developing similar adiposity. These investigations uncover a mechanism whereby a HFD-induced adipocyte/ART dialog involving MHCII instigates adipose inflammation and, together with ATM MHCII, escalates its progression.

Human Intestinal Enteroids: A New Model to Study Human Rotavirus Infection, Host Restriction and Pathophysiology

ABSTRACT Human gastrointestinal tract research is limited by the paucity of in vitro intestinal cell models that recapitulate the cellular diversity and complex functions of human physiology and disease pathology. Human intestinal enteroid (HIE) cultures contain multiple intestinal epithelial cell types that comprise the intestinal epithelium (enterocytes and goblet, enteroendocrine, and Paneth cells) and are physiologically active based on responses to agonists. We evaluated these nontransformed, three-dimensional HIE cultures as models for pathogenic infections in the small intestine by examining whether HIEs from different regions of the small intestine from different patients are susceptible to human rotavirus (HRV) infection. Little is known about HRVs, as they generally replicate poorly in transformed cell lines, and host range restriction prevents their replication in many animal models, whereas many animal rotaviruses (ARVs) exhibit a broader host range and replicate in mice. Using HRVs, including the Rotarix RV1 vaccine strain, and ARVs, we evaluated host susceptibility, virus production, and cellular responses of HIEs. HRVs infect at higher rates and grow to higher titers than do ARVs. HRVs infect differentiated enterocytes and enteroendocrine cells, and viroplasms and lipid droplets are induced. Heterogeneity in replication was seen in HIEs from different patients. HRV infection and RV enterotoxin treatment of HIEs caused physiological lumenal expansion detected by time-lapse microscopy, recapitulating one of the hallmarks of rotavirus-induced diarrhea. These results demonstrate that HIEs are a novel pathophysiological model that will allow the study of HRV biology, including host restriction, cell type restriction, and virus-induced fluid secretion. IMPORTANCE Our research establishes HIEs as nontransformed cell culture models to understand human intestinal physiology and pathophysiology and the epithelial response, including host restriction of gastrointestinal infections such as HRV infection. HRVs remain a major worldwide cause of diarrhea-associated morbidity and mortality in children ≤5 years of age. Current in vitro models of rotavirus infection rely primarily on the use of animal rotaviruses because HRV growth is limited in most transformed cell lines and animal models. We demonstrate that HIEs are novel, cellularly diverse, and physiologically relevant epithelial cell cultures that recapitulate in vivo properties of HRV infection. HIEs will allow the study of HRV biology, including human host-pathogen and live, attenuated vaccine interactions; host and cell type restriction; virus-induced fluid secretion; cell-cell communication within the epithelium; and the epithelial response to infection in cultures from genetically diverse individuals. Finally, drug therapies to prevent/treat diarrheal disease can be tested in these physiologically active cultures.

Transcriptome analysis of human adipocytes implicates the NOD-like receptor pathway in obesity-induced adipose inflammation

Adipose tissue inflammation increases with obesity, but adipocyte vs. immune cell contributions are unclear. In the present study, transcriptome analyses were performed on highly-purified subcutaneous adipocytes from lean and obese women, and differentially expressed genes/pathways were determined in both adipocyte and stromal vascular fraction (SVF) samples. Adipocyte but not SVF expression of NOD-like receptor pathway genes, including NLRP3 and PYCARD, which regulate caspase-1-mediated IL-1β secretion, correlated with adiposity phenotypes and adipocyte class II major histocompatibility complex (MHCII) gene expression, but only MHCII remained after adjusting for age and body mass index. IFNγ stimulated adipocyte MHCII, NLRP3 and caspase-1 expression, while adipocyte MHCII-mediated CD4(+) T cell activation, an important factor in adipose inflammation, induced IFNγ-dependent adipocyte IL-1β secretion. These results uncover a dialogue regulated by interactions among T cell IFNγ and adipocyte MHCII and NLRP3 inflammasome activity that appears to initiate and escalate adipose tissue inflammation during obesity.

Effectiveness of B Vitamin Supplementation Following Bariatric Surgery: Rapid Increases of Serum Vitamin B12

BackgroundFew prospective studies have compared changes of nutrient intake while assessing effectiveness of thiamin, vitamin B12, and folate supplementation to prevent B vitamin deficiencies immediately following Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG). Therefore, we determined the response to 3xa0months supplementation on maintaining blood B vitamin concentrations.MethodsWomen undergoing RYGB (nu2009=u200911) and SG (nu2009=u200911) consumed bariatric vitamin supplements (12xa0mg thiamin, 350xa0μg vitamin B12, 800xa0μg folic acid) daily for 3xa0months. Height, weight, body mass index, and blood vitamin concentrations were measured preoperatively and at 3xa0months. Wilcoxon signed-rank analyses compared body weight parameters, laboratory indices, and nutrient intake at baseline and 3xa0months.ResultsSupplementation for 3xa0months maintained blood thiamin, increased serum folate from 13.1u2009±u20095.4 to 16.3u2009±u20096.0xa0nmol/L (Pu2009=u20090.049), and increased serum vitamin B12 concentrations from 498u2009±u2009150 to 736u2009±u2009340xa0pg/mL (Pu2009=u20090.005). Dietary intake of thiamin and folate decreased in the combined surgical groups, while dietary intake of B12 was maintained. Bariatric B vitamin supplements provided multiple intakes of the Recommended Dietary Allowances (1090xa0% thiamin, 14,583xa0% vitamin B12, 200xa0% folate).ConclusionsAlthough energy intake decreased 64xa0%, B vitamin supplementation for 3xa0months resulted in a 48xa0% increase of serum vitamin B12, a modest increase of serum folate, and no reduction of blood thiamin concentrations. Long-term effects of the rapid rise of serum B12 levels attributed to the high content of supplements warrant further investigation.

Vitamin D supplementation efficacy: sleeve gastrectomy versus gastric bypass surgery.

BackgroundVitamin D deficiency is common with bariatric surgery, and few prospective studies comparing different surgical procedures have evaluated appropriate vitamin D supplementation levels. Therefore, vitamin D3 and calcium supplementation were evaluated following gastric bypass and sleeve gastrectomy.MethodsWomen consumed 2,000 international units (IU) of vitamin D3 and 1,500xa0mg calcium citrate daily for 3xa0months following gastric bypass (nu2009=u200911) and sleeve gastrectomy (nu2009=u200912). Height, weight, body mass index (BMI), serum 25-hydroxyvitamin D [25(OH)D], and serum PTH concentrations were measured preoperatively and at 3xa0months. Wilcoxon signed rank analyses compared body weight parameters, serum 25(OH)D and PTH concentrations, and dietary intakes of vitamin D and calcium preoperatively and at 3xa0months. Vitamin D deficiency was defined as a serum 25(OH)D concentration <20xa0ng/mL (50xa0nmol/L).ResultsVitamin D deficiency decreased from 60.6xa0% preoperatively to 26.1xa0% after 3xa0months (Pu2009<u20090.005). Serum 25(OH)D concentrations increased an average of 8xa0ng/mL (Pu2009<u20090.001), and PTH concentrations decreased an average of 9xa0ng/L, although reductions were not significant. Overall, the response to supplementation following gastric bypass and sleeve gastrectomy did not differ.ConclusionsReduced food intake increased the risk of vitamin D deficiency following bariatric surgery. However, daily supplementation with 2,000xa0IU of vitamin D3 and 1,500xa0mg calcium citrate significantly increased 25(OH)D concentrations and reduced the percent of women who were vitamin D deficient. Although serum 25(OH)D concentrations did not reach levels associated with detrimental health effects, several women remained vitamin D deficient and more aggressive supplementation may be indicated.

Bariatric Surgery and End-Stage Organ Failure

Morbid obesity increases the risk of complications and allograft failure in transplant patients. Bariatric surgery is both safe and effective in patients with chronic kidney disease and end-stage renal disease, improves eligibility for transplant based on body mass index, and does not affect postoperative immunosuppressant dosing regimens. Bariatric surgery in patients with liver disease has been shown to be safe and effective, although they remain at high risk in the setting of portal hypertension. Sleeve gastrectomy may become increasingly used both pretransplant and posttransplant, as it can result in low complication rates and excellent weight loss, and retains intestinal continuity.

Racial Disparity in Short-Term Outcomes after Gastric Bypass Surgery

BackgroundRoux-en-Y gastric bypass procedure is the most frequently performed bariatric surgery for the extremely obese in USA. However, the information about the effects of racial/ethnic differences, comorbidities, and medication use on weight loss outcomes is limited. The objectives of this study were to investigate if race/ethnicity, comorbidities, and medication use affect weight loss effectiveness after the surgery.MethodsThis is a retrospective observational study conducted at one teaching hospital at Houston metropolitan area, TX, USA. Patients between 18 and 64xa0years, with body mass index (BMI) of ≥40 or BMI of ≥35 with comorbidities, who had completed medical evaluations/consultations and met insurance policy requirements, were included in the study.ResultsFrom a total of 40 patients in the study (40xa0% African Americans, 35xa0% Caucasians, 17.5xa0% Hispanics, 7.5xa0% others), the weight loss was significantly greater in Caucasian patients at 6xa0months after the surgery, with mean percentage excess weight loss (%EWL) of 40.6u2009±u200917.3, as compared to all other racial groups combined at %EWL of 30.9u2009±u200911.5 (p value 0.04). No association was found between the 6-month weight loss and other variables including age, gender, BMI prior to surgery, comorbidities, and total number of medications taken before the surgery.ConclusionsThis study found that Caucasian patients had a significantly greater %EWL at 6xa0months post-op as compared to their African-American and Hispanic counterparts. No other variables exhibited significant impact on the weight loss. Further studies with a larger sample size are needed to confirm the results from this study.

A robust and non-obtrusive automatic event tracking system for operating room management to improve patient care

AbstractBackgroundnOptimization of OR management is a complex problem as each OR has different procedures throughout the day inevitably resulting in scheduling delays, variations in time durations and overall suboptimal performance. There exists a need for a system that automatically tracks procedural progress in real time in the OR. This would allow for efficient monitoring of operating room states and target sources of inefficiency and points of improvement.Study designWe placed three wireless sensors (floor-mounted pressure sensor, ventilator-mounted bellows motion sensor and ambient light detector, and a general room motion detector) in two ORs at our institution and tracked cases 24xa0h a day for over 4xa0months.ResultsWe collected data on 238 total cases (107 laparoscopic cases). A total of 176 turnover times were also captured, and we found that the average turnover time between cases was 35xa0min while the institutional goal was 30xa0min. Deeper examination showed that 38xa0% of laparoscopic cases had some aspect of suboptimal activity with the time between extubation and patient exiting the OR being the biggest contributor (16xa0%).ConclusionOur automated system allows for robust, wireless real-time OR monitoring as well as data collection and retrospective data analyses. We plan to continue expanding our system and to project the data in real time for all OR personnel to see. At the same time, we plan on adding key pieces of technology such as RFID and other radio-frequency systems to track patients and physicians to further increase efficiency and patient safety.

A Smart Trocar for Automatic Tool Recognition in Laparoscopic Surgery

Background. Operating rooms have become increasingly complex environments and more prone to errors because of loss of situation awareness. Adding computer intelligence to the operating room may help overcome these limitations particularly if the system can automatically track which step of an operation a surgeon is performing. To develop such a platform, it is necessary to track which laparoscopic instruments are being used and in which port they are inserted. This article describes the development and validation of a “Smart Trocar” that can automatically perform this function. Methods. A Smart Trocar system prototype was developed that uses a wireless camera attached to a standard laparoscopic port and custom software algorithms. The system recognizes color wheels attached to the handle of a laparoscopic instrument and compares the unique color pattern to an instrument library for proper tool identification. The system was tested for reliability in a box trainer environment using a variety of tool positions and levels of room light illumination. Results. Correct color classification was achieved in 96.7% of trials. There were no errors in detection of the color wheel in space. In addition, the distance of the color wheel from the camera did not influence results and correct classifications were evenly distributed among the 12 laparoscopic tool positions tested. Conclusion. This work describes a Smart Trocar system that identifies which laparoscopic tool is being used and in which port and proves its reliability. The system is an important element of a more comprehensive program being developed to automatically understand what step of an operation a surgeon is performing and use these data to improve situation awareness in the operating room.

Simultaneous LC-MS/MS analysis of simvastatin, atorvastatin, rosuvastatin and their active metabolites for plasma samples of obese patients underwent gastric bypass surgery

Graphical abstract Figure. No Caption available. HighlightsLC–MS/MS assay for simvastatin, atorvastatin, rosuvastatin, and active metabolites.Assay was validated following FDA bioanalytical guidelines in human lipemic plasma.Assay quantified statins and metabolites in clinical plasma of GBS obese patients. Abstract Statins, HMG‐CoA reductase inhibitors, are considered the first line treatment of hyperlipidemia to reduce the risk of atherosclerotic cardiovascular diseases. The prevalence of hyperlipidemia and the risk of atherosclerotic cardiovascular diseases are higher in obese patients. Published methods for the quantification of statins and their active metabolites did not test for matrix effect of or validate the method in hyperlipidemic plasma. A sensitive, specific, accurate, and reliable LC–MS/MS method for the simultaneous quantification of simvastatin (SMV), active metabolite of simvastatin acid (SMV‐A), atorvastatin (ATV), active metabolites of 2‐hydroxy atorvastatin (2‐OH‐ATV), 4‐hydroxy atorvastatin (4‐OH‐ATV), and rosuvastatin (RSV) was developed and validated in plasma with low (52–103 mg/dl, <300 mg/dl) and high (352–403 mg/dl, >300 mg/dl) levels of triglyceride. The column used in this method was ACQUITY UPLC BEH C18 column (2.1 × 100 mm I.D., 1.7 &mgr;m). A gradient elution of mobile phase A (10 mM ammonium formate and 0.04% formic acid in water) and mobile phase B (acetonitrile) was used with a flow rate of 0.4 ml/min and run time of 5 min. The transitions of m/z 436.3 → 285.2 for SMV, m/z 437.2 → 303.2 for SMV‐A, m/z 559.2 → 440.3 for ATV, m/z 575.4 → 440.3 for 2‐OH‐ATV and 4‐OH‐ATV, m/z 482.3 → 258.1 for RSV, and m/z 412.3 → 224.2 for fluvastatin (internal standard, IS) were determined by Selected Reaction Monitoring (SRM) method to detect transitions ions in the positive ion mode. The assay has a linear range of 0.25 (LLOQ) −100 ng/ml for all six analytes. Accuracy (87–114%), precision (3–13%), matrix effect (92–110%), and extraction recovery (88–100%) of the assay were within the 15% acceptable limit of FDA Guidelines in variations for plasma with both low and high triglyceride levels. The method was used successfully for the quantification of SMV, ATV, RSV, and their active metabolites in human plasma samples collected for an ongoing clinical pharmacokinetic and pharmacodynamic study on patients prior to and post gastric bypass surgery (GBS).