Joy Collins

Characterization of the expression of inducible nitric oxide synthase in rat and human liver during hemorrhagic shock.

It has been previously shown that the inducible nitric oxide (NO) synthase (iNOS; NOS-2) is elevated after hemorrhage, and that iNOS-derived NO participates in the upregulation of inflammation as well as lung and liver injury postresuscitation from shock. The purpose of this study was to elucidate the time course of iNOS mRNA expression, as well as the cellular and subcellular localization of iNOS protein in the liver posthemorrhage in rats subjected to varying durations of hemorrhagic shock (HS; mean arterial blood pressure [MAP] = 40 mmHg) with or without resuscitation. Expression of iNOS mRNA in rat liver by real-time reverse transcriptase (RT)-PCR demonstrated iNOS upregulation in shocked animals as compared with their sham counterparts as early as 60 min after the initiation of hemorrhage. By 1 h of HS, iNOS protein was detectable in rat liver by immunofluorescence, and this expression increased with time. Immunofluorescence localized iNOS primarily to the hepatocytes, and in particular to hepatocytes in the centrilobular regions. This analysis, confirmed by immunoelectron microscopy, revealed that iNOS colocalizes with catalase, a peroxisomal marker. Furthermore, we determined that iNOS mRNA is detectable by RT-PCR in liver biopsies from human subjects with HS (MAP < 90 mmHg) associated with trauma (n = 18). In contrast, none of the seven nontrauma surgical patients studied had detectable iNOS mRNA in their livers. Collectively, these results suggest that hepatic iNOS expression, associated with peroxisomal localization, is an early molecular response to HS in experimental animals and possibly in human patients with trauma with HS.

Preoperative weight loss in high-risk superobese bariatric patients: a computed tomography-based analysis.

BACKGROUND Superobesity, through organomegaly, excessive adiposity, and associated severe co-morbidities, is a recognized risk factor for bariatric surgery. Our study examined the utility of preoperative weight loss with a liquid low-calorie diet (LCD) as a method of risk reduction. METHODS All patients with a body mass index (BMI) >50 kg/m(2) were instructed to consume a LCD (800 kcal/d) with the goal of losing ≥10% of their body weight. The co-morbidities were monitored. The abdominal wall depth and cross-sectional areas of subcutaneous adipose tissue (SAT) at 12 and 20 cm below the costal margin, visceral adipose tissue (VAT), and liver volume were measured, using computed tomography, at baseline and after completion of the LCD. Laparoscopic gastric bypass was performed in all patients. RESULTS The study included 30 patients (27 men and 3 women) with a mean age of 53 years (range 34-53). The mean BMI was reduced from 56 kg/m(2) (range 50-69) at baseline to 49 kg/m(2) (range 43-60) after an average of 9 weeks of the LCD. The VAT decreased from a mean of 388 cm(2) to 342 cm(2). The abdominal wall depth decreased from 3.6 to 3.2 cm at 12 cm below the costal margin and from 3.7 to 3.4 cm at 20 cm. The mean SAT at both 12 and 20 cm below the costal margin had decreased from 577 cm(2) and 687 cm(2) to 509 cm(2) and 614 cm(2), respectively. The liver volume was reduced by 18%. All co-morbidities were well controlled at LCD completion. No patient died, and 2 minor complications occurred postoperatively. CONCLUSION The results of our study have shown that preoperative LCD is a safe and effective tool leading to a significant decrease in liver volume and abdominal wall depth, as well as a reduction in both VAT and SAT. Its use might contribute to improved short-term surgical outcomes in high-risk superobese patients.

Application of a trocar wound closure system designed for laparoscopic procedures in morbidly obese patients

Herniation into the trocar-site is a relatively common complication of laparoscopic surgery, and represents a serious cause of morbidity because of the potential to develop into a Richters hernia. The risk of trocar-site herniation is greater in obese and bariatric patients, because of the larger preperitoneal space and elevated intra-abdominal pressure; thus, fascial closure alone is not adequate. Full-thickness trocarwound closure can prevent this complication. However, hand suturing and some port-closure devices can be difficult to use in this patient group. We report on the use of a specialized trocar wound closure system designed for use on obese and bariatric patients. In this report, we describe use of the system in the case of a 34-year-old Caucasian female who underwent a laparoscopic Roux-en-Y gastric bypass procedure.

68 – Biology of Nitric Oxide: Measurement, Modulation, and Models

Once thought to be merely an environmental pollution by-product of industrial processes, nitric oxide (NO) is now known to be a potent biologic mediator. The discovery that NO is produced by a number of mammalian cells and that it has roles in events such as vasodilatation, neurotransmission, and immune-mediated cytotoxicity has sparked an explosion of scientific studies. Nitric oxide is among the most important signaling and effector molecules in biologic systems. In the 1980s, pioneers in the field of NO research dissected out the basic concepts of the synthesis and biology of NO, and new discoveries regarding the myriad functions of NO continue to be made on a daily basis. Despite two decades of intensive study, the role of NO in many biologic functions and disease processes remains elusive. By utilizing the currently available tools fully and by developing new innovative techniques for the detection and manipulation of NO in biologic systems, it is possible to delineate the many biologic functions of NO and NOS. It is hoped that this knowledge will allow to develop new strategies and treatments for those diseases that involve either pathologic overproduction or underproduction of NO.

A novel technique for fascial fixation of laparoscopic adjustable gastric band ports.

Access port dislodgement after laparoscopic adjustable gastric banding is a recurring problem that often requires operative revision. Securing the port to the abdominal wall fascia in the traditional way with standard instruments is challenging in obese patients due to a thick abdominal wall. Therefore, we have devised a novel and simple technique for access port fixation using the EndoStitch device.

The contribution of hiatal hernia to severe gastroesophageal reflux disease in patients with gastroschisis.

BACKGROUND A relationship between gastroschisis-associated gastroesophageal reflux (GER) and hiatal hernia (HH) has not been previously reported. In reviewing our experience with gastroschisis-related GER, we noted a surprising incidence of associated HH in patients requiring antireflux procedures. METHODS A single center retrospective chart review focused on GER in all gastroschisis patients repaired between January 1, 2000 and December 31, 2012 was performed. RESULTS Of the 141 patients surviving initial gastroschisis repair and hospitalization, 16 (11.3%) were noted to have an associated HH (12 Type I, 3 Type II, 1 Type III) on upper gastrointestinal series for severe reflux. Ten of the 13 (76.9%) patients who required an antireflux procedure had an associated HH. The time to initiation of feeds was similar in all patients, 19 and 23 days. However, time to full feedings and discharge was delayed until a median of 80 and 96 days, respectively, in HH patients. CONCLUSIONS This study describes a high incidence of associated HH in gastroschisis patients. The presence of large associated HH correlated with severe GER, delayed feeding, requirement for antireflux surgery, and a prolonged hospital stay. Patients with gastroschisis and clinically severe GER should undergo early assessment for associated HH.