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Biomedical subjects

Atul K Madan

Publications and source records attributed to Atul K Madan.

At least 37 records · Page 2Linked to original sources
PubMed2005

Involvement of multiple signaling pathways in the post-bariatric induction of IL-6 and IL-8 mRNA and release in human visceral adipose tissue.

The present studies were designed to determine the site of and the mechanism for the rapid increase in IL-6 and IL-8 mRNA observed in human visceral adipose tissue after removal during laparoscopic bariatric surgery. Upregulation of IL-6 and IL-8 mRNA as well as their release were seen within 3h whether one intact piece of tissue or minced pieces of adipose tissue were incubated in vitro. Most of the IL-6 and IL-8 mRNA content of visceral adipose tissue after 3h of incubation was in the non-fat cells. Actinomcyin D markedly reduced the upregulation of IL-6 and IL-8 mRNA. Incubation of adipose tissue explants with a soluble TNFalpha receptor (etanercept) plus a blocking antibody against IL-lbeta reduced by 55% the increase in IL-6 mRNA and by 42% that of IL-8 mRNA seen between 1 and 5h of incubation. The upregulation of IL-8 and IL-6 mRNA accumulation as well as their release over a 2 or 4h incubation was reduced by around 50% in the presence of an inhibitor of the p38 MAPK or an inhibitor of the NFkappaB pathway and by 85% in the presence of both inhibitors. The data suggest that the relative trauma and/or hypoxia that occurs when adipose tissue is removed results in the release of TNFalpha and IL-1beta. These cytokines, and probably other factors as well, enhance IL-6 and IL-8 mRNA accumulation in human adipose tissue explants through mechanisms involving the p38 MAPK and NFkappaB pathways.

Adipocytes↗
PubMed2005

Participants' opinions of laparoscopic training devices after a basic laparoscopic training course.

BACKGROUND: Basic laparoscopic skills are initially best taught and practiced in an inanimate setting. Various devices are used to aid in this education of laparoscopic skills. These devices range from simple box trainers to sophisticated virtual reality trainers. This investigation tested the hypothesis that participants would prefer one trainer to another trainer. METHODS: Preclinical medical students volunteered for this study. All underwent a porcine laboratory. The students were then divided into 3 groups by method of training: group A--a virtual reality trainer (MIST-VR), group B--an inanimate box trainer (LTS 2000), and group C--both trainers. Each group participated in 10 laboratories with the assigned trainer(s). After completion of the laboratories, all students underwent a similar porcine laboratory. During this laboratory, opinions of each trainer and specific tasks were ascertained from each student. RESULTS: No statistical difference was seen between groups A and B when asked if their specific trainer helped their skills, was realistic, helped in the animal laboratory, and was interesting. When group C was asked the same questions about each trainer, no statistical difference was seen except that 47% thought the MIST-VR was not realistic as opposed to 0% who thought the LTS 2000 was not realistic (P <.003). The level of difficulty of each task correlated with how much the specific task helped in development of skills for both trainers (P <.0001). In group C, 89% of the participants thought the LTS 2000 helped more that the MIST-VR and 56% thought the LTS 2000 was more interesting than the MIST-VR. In addition, 83% of students in group C chose LTS 2000 when asked to pick only one trainer. CONCLUSIONS: While virtual reality trainers may have some advantages, most participants feel that inanimate box trainers help more, are more interesting, and should be chosen over virtual reality trainers if only one trainer is allowed. Further studies need to investigate if the opinions affect participants' utilization of these trainers.

Clinical Competence↗
PubMed2005

Insulin enhances vascular endothelial growth factor, interleukin-8, and plasminogen activator inhibitor 1 but not interleukin-6 release by human adipocytes.

The present studies were designed to investigate the hormonal regulation of vascular endothelial growth factor (VEGF) release by human subcutaneous adipose tissue explants and adipocytes incubated in primary culture for 48 hours. Vascular endothelial growth factor and IL-8 release by adipocytes were less than 10% of that by tissue explants, whereas that of leptin in adipocytes was comparable to that by tissue. Dexamethasone inhibited VEGF formation by both adipose tissue explants and isolated adipocytes, whereas insulin stimulated VEGF release only in isolated adipocytes. Insulin also enhanced the formation of IL-8 and plasminogen activation inhibitor 1 (PAI-1), but not that of IL-6 by adipocytes although having little effect on that of IL-6 or PAI-1 by adipose tissue explants. Pertussis toxin stimulated lipolysis and inhibited leptin release by human adipose tissue or adipocytes but did not affect release of IL-8 or VEGF. Isoproterenol also stimulated lipolysis by human adipocytes, but this was not accompanied by any significant changes in VEGF, IL-8, IL-6, or PAI-1 release. In contrast, insulin stimulated VEGF release by human adipocytes, and this stimulation was enhanced in the presence of isoproterenol. Insulin stimulated VEGF formation as well as that of PAI-1 by human adipocytes, but not by explants under conditions where it had little effect on that of IL-6. The ability of insulin to stimulate VEGF formation by adipocytes suggests that the elevated circulating levels of insulin in obesity promote angiogenesis in adipose tissue as well as the enhanced accumulation of fat in human adipocytes.

Adipocytes↗
PubMed2005

Transforming growth factor beta1 release by human adipose tissue is enhanced in obesity.

The present studies examined the effect of obesity in humans on the release of transforming growth factor beta1 (TGF-beta1) by human adipose tissue. The regulation of TGF-beta1 release by adipose tissue as well as the question of whether its release is due to the adipocytes or the nonfat cells in adipose tissue was also examined. There was a statistically significant (r=0.50) correlation between the body mass index of the fat donors and the subsequent release of TGF-beta1 release by subcutaneous adipose tissue. There was also a positive correlation between total TGF-beta1 release by adipose tissue explants and body fat content (r=0.69). The question of whether tumor necrosis factor alpha (TNF-alpha) and/or interleukin 1 beta (IL-1 beta) regulate the release of TGF-beta1 was investigated by incubation of adipose tissue explants with a soluble human TNF-alpha receptor (etanercept) and a neutralizing antihuman IL-1 beta antibody. The release of TGF-beta1 over 48 hours by adipose tissue explants was significantly enhanced in the presence of both the inhibitor of TNF-alpha and of IL-1 beta. It is of interest, in view of the elevated circulating insulin in blood of morbidly obese women, that the release of TGF-beta1 by adipose tissue was enhanced in the presence of insulin. The question of whether the release of TGF-beta1 by human adipose tissue explants was primarily due to adipocytes, as is the case for leptin, or the nonfat cells present in human adipose tissue, as is the case for IL-8 and prostaglandin E(2), was examined. The release of TGF-beta1 was primarily by the nonfat cells of human adipose tissue because release by adipocytes was less than 10% of that by the nonfat cells of adipose tissue.

Adipocytes↗
PubMed2005

Laparoscopic baseline ability assessment by virtual reality.

BACKGROUND: Assessment of any surgical skill is time-consuming and difficult. Currently, there are no accepted metrics for most surgical skills, especially laparoscopic skills. Virtual reality has been utilized for laparoscopic training of surgical residents. Our hypothesis is that this technology can be utilized for laparoscopic ability metrics. METHODS: This study involved medical students with no previous laparoscopic experience. All students were taken into a porcine laboratory in order to assess two operative tasks (measuring a piece of bowel and placing a piece of bowel into a laparoscopic bag). Then they were taken into an inanimate lab with a Minimally Invasive Surgery Trainer-Virtual Reality (MIST-VR). Each student repeatedly performed one task (placing a virtual reality ball into a receptacle). The students' scores and times from the animate lab were compared with average economy of movement and times from the MIST-VR. The MIST-VR scored both hands individually. RESULTS: Thirty-two first- and second-year medical students were included in the study. There was statistically significant (P < 0.05) correlation between 11 of 16 possible relationships between the virtual reality trainer and operative tasks. CONCLUSION: While not all of the possible relationships demonstrated statistically significant correlation, the majority of the possible relationships demonstrated statistically significant correlation. Virtual reality may be an avenue for measuring laparoscopic surgical ability.

Adult↗
PubMed2005

One-stitch laparoscopic gastric bypass technique for adolescents.

Morbid obesity is increasingly recognized in children and adolescents. The National Institute of Health Consensus Conference has concluded that bariatric surgery is the only consistent effective method for achieving long-term weight loss. Advantages of the laparoscopic approach, which include decreased hospital stay and morbidity, have been demonstrated in randomized controlled studies. Herein, we describe our technique of laparoscopic Roux-en-Y gastric bypass.

Adolescent↗
PubMed2005

Weight changes in spouses of gastric bypass patients.

BACKGROUND: The effectiveness of gastric bypass for weight loss has been demonstrated. No study has documented the effect of this surgery on patient spouses' weight. Excess leftover food may be consumed by the spouses of gastric bypass patients, which may increase the total caloric intake compared to the preoperative intake. This investigation tested the hypothesis that there would be a significant change in patient spouse's weight. METHODS: Patients who underwent Roux-en-Y gastric bypass (RYGBP) > or = 12 months before were included. Preoperative weights of their spouses were requested before RYGBP surgery. Current weights of spouses were collected > or = 12 months postoperatively. Chi-squared tests were used for statistical analysis. RESULTS: 63 patients were included in this study. 1 patient was divorced and current data was not available. 3 patients' spouses themselves had RYGBP during the study period, and their average weight loss was 49 kg. Of the spouses who had a significant change in weight (but did not have a RYGBP), 13 lost weight and 20 gained weight. In this subgroup of spouses, 75% (15/20) of obese spouses gained weight compared to only 38% (5/13) non-obese spouses (P <0.04). CONCLUSIONS: Patients' spouses who are obese are more likely to have weight gain while the patients lose weight after RYGBP. Preoperative counseling should be offered to spouses of potential bariatric surgery patients, especially to spouses who are obese. This phenomenon suggests that obese spouses of bariatric patients should be counselled regarding weight gain or even be considered for candidates for bariatric surgery.

Adult↗
PubMed2005

Laparoscopic removal of gastric band after open banded gastric bypass.

Open banded gastric bypass has been the choice of some bariatric surgeons. This procedure includes a band (of various materials) around the gastric pouch. While there are advantages to this band, erosion and/or displacement of the band may occur. We describe a case of a symptomatic displaced band which was treated by laparoscopic removal. Laparoscopic removal of the band after open banded gastric bypass is feasible. Revision of previous bariatric surgery may be performed laparoscopically if the technical expertise is available.

Body Mass Index↗
PubMed2005

Patients postoperatively forget aspects of preoperative patient education.

BACKGROUND: Preoperative patient education is critically important to the success of any bariatric operation. In our clinic, we perform extensive preoperative education and informed consent. Part of the informed consent process includes a preoperative true/false quiz. This study tests the hypothesis that postoperative patients do not recall key components of their preoperative education. METHODS: Preoperatively, all patients were required to take the true/false quiz and retake it, if necessary, until they received all the questions correct. All patients were given their preoperative informed consent quiz again at least 1 month after laparoscopic gastric bypass, during their postoperative clinic visit. Patients >1 year postoperatively from surgery were compared to patients <1 year postoperatively. RESULTS: 63 patients were included in this study. Originally, 46% of patients did not get all the questions correct the first time; mean score on the quiz preoperatively was 95%. Patients took the test an average of 8 months after surgery. Postoperatively, 46% of patients did not get all the questions correct; mean score on the quiz was 96%. The 2 most common incorrect answers were: "Obesity surgery is basically an aid to dieting: it does not mean that you will lose weight no matter what you eat or do (True)" and "Diabetes, high blood pressure, back pain and similar ailments always get better after obesity surgery (False)". Patients >1 year postoperative were more likely not to get all the questions correct (80% vs 36%; P<0.01; two-tailed Fisher's exact test). CONCLUSIONS: Patients do not remember basic preoperative education facts after their bariatric surgery. Despite maximal efforts in verifying preoperative education, patients often forget this critical information after bariatric surgery. Patients 1 year after surgery forget more information.

Bariatrics↗
PubMed2005

Internet use in the bariatric surgery patient population.

BACKGROUND: Many patients rely on the Internet for gathering medical information. Bariatric patients appear to explore the Internet for information regarding weight loss surgery. This investigation studied the hypothesis that Internet use is common among the bariatric population. METHODS: From Oct 1 to Dec 31, 2003, every patient who visited our bariatric clinic was asked to fill out a questionnaire. This survey contained questions concerning use of the Internet and E-mail. RESULTS: Of the 127 respondents, 89% owned a computer, had Internet access, and had an E-mail address. 85% of the patients had searched the Internet for bariatric information, and 98% of these patients (91/93) found the information useful. Of the patients who had access to the Internet, 36% searched for information about the hospital, 40% about the clinic, and 54% about the surgeon. Most of the patients believed that all doctors and all clinics should be available via E-mail (88% and 92% respectively). CONCLUSIONS: Most patients who come to a bariatric clinic are Internet savvy. It is helpful for bariatric surgeons and clinics to post information about themselves on the Internet and to be available via E-mail.

Adolescent↗
PubMed2005

Laparoscopic Roux-en-Y gastric bypass with subtotal gastrectomy.

Laparoscopic gastric bypass is a common procedure for morbid obesity. After gastric bypass, the distal stomach is unavailable for surveillance. When a suspicious distal gastric lesion is present preoperatively, a distal subtotal gastrectomy may be needed. Herein we describe such a case performed laparoscopically. Laparoscopic gastric bypass with subtotal gastrectomy for morbid obesity should be considered for patients with suspicious distal gastric lesions.

Anastomosis, Roux-en-Y↗
PubMed2004

Solid and papillary epithelial neoplasm of the pancreas.

Solid and papillary epithelial (SPEN) is an uncommon pancreatic tumor often seen in young females. Although most of these neoplasms have a benign course, SPEN do have malignant potential. Treatment is surgical which is usually feasible either via enucleation or more radical procedures. Below we discuss diagnosis, treatment, and prognosis in detail.

Biopsy, Needle↗
PubMed2004

Comparison of the release of adipokines by adipose tissue, adipose tissue matrix, and adipocytes from visceral and subcutaneous abdominal adipose tissues of obese humans.

The purpose of this study was to examine the source of adipokines released by the visceral and sc adipose tissues of obese humans. Human adipose tissue incubated in primary culture for 48 h released more prostaglandin E(2), IL-8, and IL-6 than adiponectin, whereas the release of plasminogen activator inhibitor 1 and hepatocyte growth factor was less than that of adiponectin but greater than that of leptin. IL-10 and TNFalpha were released in amounts less than those of leptin, whereas vascular endothelial growth factor and IL1-beta were released in much lower amounts. The accumulation of adipokines was also examined in the three fractions (adipose tissue matrix, isolated stromovascular cells, and adipocytes) obtained by collagenase digestion of adipose tissue. Over 90% of the adipokine release by adipose tissue, except for adiponectin and leptin, could be attributed to nonfat cells. Visceral adipose tissue released greater amounts of vascular endothelial growth factor, IL-6, and plasminogen activator inhibitor 1 compared with abdominal sc tissue. The greatly enhanced total release of TNFalpha, IL-8, and IL-10 by adipose tissue from individuals with a body mass index of 45 compared with 32 was due to nonfat cells. Furthermore, most of the adipokine release by the nonfat cells of adipose tissue was due to cells retained in the tissue matrix after collagenase digestion.

Abdomen↗
PubMed2004

Use of ciprofloxacin in the treatment of hospitalized patients with intra-abdominal infections.

BACKGROUND: Numerous combination and single-agent antimicrobial regimens are available for the treatment of intra-abdominal infections. Selection of empiric agents must be directed at providing reliable activity against endotoxin-generating Escherichia coli, other gram-negative facultative bacteria, and anaerobes such as Bacteroides fragilis. Safety profiles, pharmacokinetic profiles, and cost-effectiveness must also be considered. Use of fluoroquinolones for the treatment of intra-abdominal infections has recently been advocated. METHODS: We review 2 prospective, comparative clinical trials conducted between 1992 and 2002 that evaluated the efficacy and safety of IV ciprofloxacin in patients with intra-abdominal infections. Separate pharmacoeconomic analyses conducted for each study are also reviewed. RESULTS: A total of 4 ciprofloxacin studies (2 clinical, 2 pharmacoeconomic) comprise the database. The combination of ciprofloxacin plus metronidazole was at least as effective as imipenem/cilastatin and clinically more effective than piperacillin/tazobactam therapy, based on clinical success end points. In 1 trial, treatment success for the clinically valid population was reported for 84% (93/111) of patients treated with IV ciprofloxacin/metronidazole, 86% (91/106) of those treated with IV/oral ciprofloxacin/metronidazole, and 81% of those treated with IV imipenem/cilastatin (91/113). The IV/oral ciprofloxacin/metronidazole regimen had a statistically significant lower mean infection-related cost than the IV only ciprofloxacin/metronidazole plus imipenem groups (difference of approximately 1100 US dollars; P = 0.029). In the second clinical trial, clinical resolution rates were statistically different for patients receiving IV/oral ciprofloxacin/metronidazole (74%) versus IV piperacillin/tazobactam therapy (63%; P = 0.047). Ciprofloxacin/metronidazole was more cost-effective compared with piperacillin/tazobactam (2200 US dollars-3600 US dollars lower cost-effective ratios per patient) regardless of whether the patient had a diagnosis of appendicitis or whether a switch to an oral drug was permissible. CONCLUSIONS: In the studies reviewed herein, the combination of ciprofloxacin plus metronidazole was an effective and safe regimen for the treatment of intra-abdominal infections. This regimen has potential advantages over exclusively IV regimens, including the option of sequential IV/oral therapy, patient convenience, cost savings, and reduced hospital stay.

Abdominal Abscess↗
PubMed2004

Minimally invasive surgery for achalasia: a 10-year experience.

Minimally invasive esophagomyotomy for achalasia has become the preferred surgical treatment; the employment of a concomitant fundoplication with the myotomy is controversial. Here we report a retrospective analysis of 53 patients with achalasia treated with laparoscopic Heller myotomy; fundoplication was used in all patients except one, and 48 of the fundoplications were complete (floppy Nissen). There were no deaths or reoperations, and minor complications occurred in three patients. Good-to-excellent long-term results were obtained in 92% of the subjects (median follow-up 3 years). Two cases (4%) of persistent postoperative dysphagia were documented, one of which was treated with dilatation. Postoperative reflux occurred in five patients, four of whom did not receive a complete fundoplication; these patients were well controlled with medical therapy. We suggest that esophageal achalasia may be successfully treated with laparoscopic Heller myotomy and floppy Nissen fundoplication with an acceptable rate of postoperative dysphagia.

Adult↗
PubMed2004

Effect of body mass index on nonalcoholic fatty liver disease in patients undergoing minimally invasive bariatric surgery.

The risk factors for nonalcoholic fatty liver disease in patients undergoing bariatric surgery are under study. We wanted to determine the correlation between nonalcoholic fatty liver disease and patient factors such as obesity and liver function tests. A retrospective analysis was performed on 177 nonalcoholic morbidly obese patients who underwent laparoscopic Roux-en-Y gastric bypass with liver biopsy, to identify risk factors for nonalcoholic fatty liver disease. The histologic grade of liver disease was compared with preoperative body mass index, age, and liver function tests. Simple steatosis and steatohepatitis were present in 90% and 42% of patients, respectively. Elevated transaminase levels were an independent risk for liver disease. Body mass index and liver disease were not correlated with univariate analysis. Regression analysis performed on age, body mass index, and liver disease demonstrated that the risk for liver disease increased with body mass index in the younger (<35 years old) age group and decreased with body mass index in the older (>45 years old) age group. There was a high incidence of steatosis and steatohepatitis in these nonalcoholic bariatric patients, and elevated transaminase level was indicative of disease. Body mass index was a positive risk factor for liver disease in younger patients but a negative risk factor in the older patients.

Adult↗
PubMed2004

Laparoscopic transgastric esophageal mucosal resection for high-grade dysplasia.

BACKGROUND: High-grade dysplasia of the esophageal mucosa has been shown to be a precursor to adenocarcinoma. In addition to esophagectomy, multiple ablative endoscopic techniques have evolved for the management of this condition. As a surgical alternative to esophagectomy, we describe for the first time a new option in the treatment of high-grade dysplasia. MATERIALS AND METHODS: Two patients with a history of gastroesophageal reflux disease (GERD) underwent upper gastrointestinal endoscopy which demonstrated high-grade dysplasia of the distal esophagus. The first patient had a short segment (0.5-1.0 cm), and the second patient had a longer (2 cm) segment of dysplasia. The patient is placed in the modified lithotomy position. Five trocars are placed as if to perform a fundoplication. A complete circumferential mobilization of the esophagus is performed. The short gastric vessels are divided with the harmonic scalpel, to free up the fundus of the stomach. An anterior horizontal gastrotomy is performed three to four centimeters below the gastroesophageal junction. A solution of epinephrine and normal saline (1:100,000) is injected into the mucosa at the Z-line and, utilizing specially designed hook electrocautery, the mucosa is incised circumferentially around a lighted bougie. Using blunt dissection the mucosa is undermined, elevated, and excised in four quadrants. Three centimeters of the distal esophageal mucosa are resected. The gastrotomy is then closed using a linear stapler, and a 360 degrees fundoplication is performed around a 50 Fr bougie. RESULTS: High-grade dysplasia was identified in the specimens from both patients; however, neither patient was found to have carcinoma in situ or invasive esophageal cancer. Our first patient has been followed for twenty months, the second for ten months. Both patients underwent routine upper gastrointestinal endoscopy for surveillance of the healing process. At eight months, the mucosa of the first patient showed complete regeneration of squamous epithelium. Our most recent patient appears to be progressing without complications and has also demonstrated normal squamous epithelium at ten months postoperatively, without changes of Barrett's epithelium. CONCLUSION: The technique of laparoscopic transgastric esophageal mucosal resection is feasible and may be proven to be an alternative to esophagectomy for the management of high-grade dysplasia.

Adult↗