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S Eubanks

Publications and source records attributed to S Eubanks.

At least 19 recordsLinked to original sources
PubMed2001

Laparoscopy and the internet. A surgeon survey.

BACKGROUND: The Internet has become an important new tool for the delivery and acquisition of medical information. METHODS: A 13-item questionnaire designed to collect information on the attitudes and practices of surgeons regarding the use of the Internet as a medical resource was posted on the World Wide Web and also sent via e-mail. RESULTS: Over a 2-month period, 459 surgeons were enrolled in this study. Most of the respondents were identified as male surgeons (96%) between the ages of 31 and 50 years (79.25%). They accessed the Internet mainly from their homes (67.10%) and offices (17%) using 56 Kbps (34.86%) and 33.6 Kbps (21.79%) modems. These participants indicated that they use the Internet to expand their knowledge of general surgery (78.87%), learn more about technologies related to the practice of surgery (74.51%), access the Medline medical database (73.20%), and locate other resources for academic purposes (68%). Approximately half of them said that they favored the use of robotic assist devices in the operating room (53%), and most supported the use of technology for telementoring purposes (78%). Almost 80% professed an interest in video streaming technology applied to surgical education. CONCLUSIONS: This study showed that the Internet is a useful and powerful real-time survey tool that can help us to assess the impact of the World Wide Web and related technologies on surgical education and practice. However, the respondents in this study belong to a biased group that is already familiar with the Internet and computer technology and thus may not be representative of the surgical community as a whole.

Adult↗
PubMed2001

Effects of diabetes insipidus mutations on neurophysin folding and function.

Mechanisms underlying the pathogenicity of diabetes insipidus mutations were probed by studying their effects on the properties of bovine oxytocin-related neurophysin. The mutations G17V, DeltaE47, G57S, G57R, and C67STOP were each shown to have structural consequences that would diminish the conformational stability and folding efficiency of the precursors in which they were incorporated, and factors contributing to the origins of these property changes were identified. Effects of the mutations on dimerization of the folded proteins were similarly analyzed. The projected relative impact of the above mutations on precursor folding properties qualitatively parallels the reported relative severity of their effects on the biological handling of the human vasopressin precursor, but quantitative differences between thermodynamic effects and biological impact are noted and explored. The sole mutation for which no clear thermodynamic basis was found for its pathogenicity was 87STOP, suggesting that the region of the precursor deleted by this mutation plays a role in targeting independent from effects on folding, or participates in stabilizing interactions unique to the human vasopressin precursor.

Amino Acid Sequence↗
PubMed2000

Modulation of dimerization, binding, stability, and folding by mutation of the neurophysin subunit interface.

Bovine neurophysins, which have typically served as the paradigm for neurophysin behavior, are metastable in their disulfide-paired folded state and require ligand stabilization for efficient folding from the reduced state. Studies of unliganded porcine neurophysin (oxytocin-associated class) demonstrated that its dimerization constant is more than 90-fold greater than that of the corresponding bovine protein at neutral pH and showed that the increased dimerization constant is accompanied by an increase in stability sufficient to allow efficient folding of the reduced protein in the absence of ligand peptide. Using site-specific mutagenesis of the bovine protein and expression in Escherichia coli, the functional differences between the bovine and porcine proteins were shown to be attributable solely to two subunit interface mutations in the porcine protein, His to Arg at position 80 and Glu to Phe at position 81. Mutation of His-80 alone to Arg had a relatively small impact on dimerization, while mutation to either Glu or Asp markedly reduced dimerization in the unliganded state, albeit with apparent retention of the positive linkage between dimerization and binding. Comparison of the peptide-binding constants of the different mutants additionally indicated that substitution of His-80 led to modifications in binding affinity and specificity that were independent of effects on dimerization. The results demonstrate the importance of the carboxyl domain segment of the subunit interface in modulating neurophysin properties and suggest a specific contribution of the energetics of ligand-induced conformational change in this region to the overall thermodynamics of binding. The potential utility to future studies of the self-folding and monomeric mutants generated by altering the interface is noted.

Amino Acid Sequence↗
PubMed2000

RETRACTED: Dual signaling regulated by calcyon, a D1 dopamine receptor interacting protein.

The synergistic response of cells to the stimulation of multiple receptors has been ascribed to receptor cross talk; however, the specific molecules that mediate the resultant signal amplification have not been defined. Here a 24-kilodalton single transmembrane protein, designated calcyon, we functionally characterize that interacts with the D1 dopamine receptor. Calcyon localizes to dendritic spines of D1 receptor-expressing pyramidal cells in prefrontal cortex. These studies delineate a mechanism of Gq- and Gs-coupled heterotrimeric GTP-binding protein-coupled receptor cross talk by which D1 receptors can shift effector coupling to stimulate robust intracellular calcium (Ca2+i) release as a result of interaction with calcyon. The role of calcyon in potentiating Ca2+-dependent signaling should provide insight into the D1 receptor-modulated cognitive functions of prefrontal cortex.

Amino Acid Sequence↗
PubMed2000

Safety and efficacy of India ink and indocyanine green as colonic tattooing agents.

BACKGROUND: Controversy exists concerning the safety and efficacy of colonic tattooing for the intraoperative identification of polypectomy sites. The purpose of this study was to determine (1) the concentrations of India ink and indocyanine green that resulted in high-visibility tattoos without significant tissue inflammation and (2) the India ink injection volume that produces best visibility at colonoscopy, laparoscopy, and laparotomy. METHODS: Twenty-two New Zealand white rabbits (2 kg) were anesthetized and injected with India ink (undiluted 1:10, 1:50, 1:100, 1:1000, 1:10,000) and indocyanine green as an undiluted, concentrated formulation (25 mL/2 mL solvent) or in a diluted form (25 mg/5 mL solvent) at various concentrations (1:10, 1:50, 1:100). Tuberculin syringes were used to create a 0.1 mL serosal bleb at two injection sites 2 cm apart. Laparotomy was repeated at days 1, 3, and 7 after injection. Additionally, 16 rabbits were injected with India ink at laparotomy and re-explored at 1 and 5 months. Twelve mongrel dogs (20 kg) were injected with 1.0 mL volumes. Re-exploration by colonoscopy, laparoscopy, and laparotomy was done at 7 days and 1 month. Tattoo visibility at re-exploration in both animal models was graded on a scale (0 = agent not seen, 1 = seen with difficulty, 2 = easily seen). Histology in the rabbit was judged by degrees of inflammation (0 = no inflammation, 2 = mild inflammation, 4 = moderate inflammation, 6 = severe inflammation). RESULTS: The concentrated indocyanine green solution was easily visible only on day 1 in the rabbit. Injections of both concentrated and diluted indocyanine green caused mucosal ulceration and moderate to severe inflammation. India ink studied at 7 days, 1 month, and 5 months after injection in the rabbit model was visible at all concentrations. The undiluted and 1:10 concentrations were easily seen and showed evidence of mucosal ulceration. Tattoos produced with all other India ink concentrations were visible without gross inflammation. India ink was also studied at 7 days and 1 month in dogs. The tattoo with the 1:100 concentration at 0.5 mL was seen consistently at colonoscopy, laparoscopy, and laparotomy with only a mild submucosal reaction at 7 days. The tattoos produced with the 1:100 and 1:1000 concentrations at 0.5 mL and 1.0 mL injection volumes were easily seen by all methods of intraabdominal visualization at 1 month with similar histology. CONCLUSION: Indocyanine green was an ineffective colonic tattooing agent. India ink was an effective colonic tattooing agent. Dilute concentrations that caused little to no inflammation could be visualized at 7 days and 1 month in rabbits and dogs and at 5 months in rabbits. India ink, at appropriated concentrations, appears to be a safe short- and long-term colonic tattooing agent.

Animals↗
PubMed1999

Expression, folding, and thermodynamic properties of the bovine oxytocin-neurophysin precursor: relationships to the intermolecular oxytocin-neurophysin complex.

Earlier thermodynamic studies of the intermolecular interactions between mature oxytocin and neurophysin, and of the effects of these interactions on neurophysin folding, raised questions about the intramolecular interactions of oxytocin with neurophysin within their common precursor. To address this issue, the disulfide-rich precursor of oxytocin-associated bovine neurophysin was expressed in Escherichia coli and folded in vitro to yield milligram quantities of purified protein; evidence of significant impediments to yield resulting from damage to Cys residues is presented. The inefficiency associated with the refolding of reduced mature neurophysin in the presence of oxytocin was found not to be alleviated in the precursor. Consistent with this, the effects of pH on the spectroscopic properties of the precursor and on the relative stabilities of the precursor and mature neurophysin to guanidine denaturation indicated that noncovalent intramolecular bonding between oxytocin and neurophysin in the precursor had only a small thermodynamic advantage over the corresponding bonding in the intermolecular complex. Loss of the principal interactions between hormone and protein, and of the enhanced stability of the precursor relative to that of the mature unliganded protein, occurred reversibly upon increasing the pH, with a midpoint at pH 10. Correlation of these results with evidence from NMR studies of structural differences between the precursor and the intermolecular complex, which persist beyond the pH 10 transition, suggests that the covalent attachment of the hormone in the precursor necessitates a conformational change in its neurophysin segment and leads to properties of the system that are distinct from those of either the liganded or unliganded mature protein.

Animals↗
PubMed1999

Laparoscopic biliary and enteric bypass.

Very few patients with a periampullary neoplasm present with resectable disease. Consequently, various operative and non-operative techniques have been developed to palliate patients with unresectable periampullary disease. Laparoscopic biliary (cholecystojejunostomy) and enteric bypass (gastrojejunostomy) are reasonable options as compared to their open counterparts for operative palliation. However, only a limited number of carefully selected patients meet selection criteria for laparoscopic palliation.

Bile Duct Neoplasms↗
PubMed1999

Preface

Explore the source record for details and available documents.

Journal Article↗
PubMed1999

Diagnostic laparoscopy outside of the operating room.

Laparoscopy is increasingly being used as a diagnostic technique to characterize intraperitoneal processes. This technique can be highly informative when applied in settings such as the intensive care unit, the emergency room, the trauma bay, and the office. Diagnostic laparoscopy is an excellent method to evaluate intraperitoneal processes and should be part of the general surgeon's armamentarium of skills. In this paper, the technique of diagnostic laparoscopy and its role outside of the operating room setting is reviewed. Diagnostic laparoscopy is also compared with other diagnostic modalities.

Contraindications↗
PubMed1997

Laparoscopic ventral and incisional hernioplasty.

BACKGROUND: While the first laparoscopic ventral hernia repair was reported in 1992, there have been no studies comparing laparoscopic to conventional ventral herniorrhaphy. METHODS: Twenty-one ventral hernias repaired laparoscopically are compared to a similar group of 16 patients undergoing traditional open repair during a 2-year period. Operative and hospital courses along with outcomes and cost analysis are analyzed. RESULTS: There was no statistical difference between groups in number of previous abdominal operations, prior hernia repairs, and comorbidities. Patients undergoing open repair were older with larger fascial defects. Open repairs had a shorter operative time as compared to the laparoscopic group, but statistically longer postoperative stays and costs. Postoperative complications occurred in 31% of the open group and 23% of the laparoscopic group. There were two recurrences in each group. CONCLUSIONS: Laparoscopic herniorrhaphy is as safe and effective as the traditional open technique with shorter length of stay and decreased hospital costs.

Adult↗
PubMed1997

Pneumonia I and Pneumonia II Projects.

The need for timely and efficient treatment is assuming even greater significance, with pneumonia discharges increasing from 5,862 in 1992 to 7,870 in 1994. These two projects, involving a total of 13 hospitals, evaluated the timeliness of antibiotic administration for pneumonia patients. Baseline data revealed opportunities for improving process of care at all hospitals. After implementation of improvement plans, the majority of hospitals increased the percentage of patients receiving antibiotics within four hours of admission. This evaluation of the antibiotic delivery system can also be adapted to other diagnoses and medications.

Anti-Bacterial Agents↗
PubMed1997

Laparoscopic colectomy. Prospects and problems.

This article provides a fundamental review of laparoscopic colectomies. An overview of the physiology of laparascopic procedures is given as an introduction to the rationale of laparoscopic colectomies. A review of the current published literature including indications and an overview of laparoscopic bowel procedures for malignant diseases are presented.

Anastomosis, Surgical↗
PubMed1996

Low insertion of hepatic segmental duct VII-VIII is an important cause of major biliary injury or misdiagnosis.

BACKGROUND: The importance of variant anatomy is only mentioned generally in most articles in this era of laparoscopic cholecystectomy. We report a series of 14 patients in whom a seemingly low insertion of hepatic segmental duct VII-VIII was clinically important. METHODS: The patients were managed at Duke University Medical Center. Two intraoperative videotapes of injury were reviewed. RESULTS: Three categories of patients were identified: 6 patients who had injury in association with another major injury to the biliary system, 7 patients who had an isolated VII-VIII system injury, and 1 patient with a Klatskin tumor in whom the unobstructed variant duct was stented. After appropriate evaluation, all patients were successfully treated. Several lawsuits resulted, even when the injury was seemingly minor. Symptoms developed in all patients who filed lawsuits, but none in those who did not. CONCLUSION: Appreciation of the VII-VIII biliary variant can lead to avoidance of injury or to a successful repair. The injury can easily occur despite "normal" cholangiography. Successful clinical outcome does not necessarily correlate with freedom from lawsuits.

Bile Duct Neoplasms↗
PubMed1996

Laparoscopic radical prostatectomy in the canine model.

The purpose of this study was to determine the feasibility of performing laparoscopic radical prostatectomy in a canine model. Laparoscopic radical prostatectomy was performed on six adult male canines. A new endoscopic needle driver was used to construct a secure vesicourethral anastomosis. Average operative time required to complete the procedure was 304 min (range 270-345 min). Dissection of the prostate gland took an average of 67 min (range 35-90 min), and construction of the vesicourethral anastomosis took 154 min (rage 80-240 min). There were no intraoperative complications and only one postoperative complication (anastomotic leak). Five of the six animals recovered uneventfully from the procedure, and their foley catheters were removed 10-14 days postoperatively after a retrograde cystourethrogram demonstrated an intact vesicourethral anastomosis. Four (80%) of the surviving animals were clinically continent within 10 days after catheter removal. Post mortem examination confirmed that the vesicourethral anastomosis was intact with no evidence of urine extravasation. These data demonstrate the feasibility of laparoscopic radical prostatectomy in a canine model, and suggest that additional work with this technique should be continued to develop its potential clinical application.

Animals↗
PubMed1996

Mechanisms of gastric and esophageal perforations during laparoscopic Nissen fundoplication.

OBJECTIVE: The purpose of this study was to determine possible mechanisms of 17 gastric and esophageal perforations that occurred during laparoscopic Nissen fundoplication. METHODS: Specific details of each perforation relating to mechanism of injury, surgeon experience, diagnosis, treatment, and outcome were obtained. For each perforation, an attempt was made to accurately determine the mechanism of perforation. RESULTS: Three mechanisms accounted for the 17 perforations, the majority of which occurred within the first ten laparoscopic Nissen fundoplications performed by the surgeon. Ten perforations resulted from injuries related to improper retroesophageal dissection, five occurred during passage of the bougie dilator or nasogastric tube, and two occurred after surgery secondary to suture pullthrough. Six patients received a delayed diagnosis, which adversely affected outcome. Most of the perforations were successfully managed by primary closure and wrap to include the repair. Morbidity was significantly increased for perforations recognized late. One death, attributed to sepsis, occurred in association with a delay in diagnosis. CONCLUSIONS: Gastric and esophageal perforations are serious complications of the new laparoscopic method of Nissen fundoplication. The mechanisms of these complications are specifically related to limitations of the laparoscopic technique. Prevention of these potentially lethal complications requires a full understanding of the detailed anatomy of the gastroesophageal region and awareness of the recognized mechanisms of perforation.

Adult↗
PubMed1995

Laparoscopic diagnosis and treatment of Morgagni hernia.

The application of new minimally invasive techniques in the diagnosis and treatment of surgically correctable diseases continues to produce impressive results. Herniae of the Foramen of Morgagni are unusual abdominal wall defects which have historically been difficult to diagnose. Interestingly, laparoscopy was utilized for the diagnosis and repair of three such herniae during a 5-month period. All of these repairs were performed by one primary author in conjunction with co-authors. In this report we will review this rare hernia and report our technique of repair. We believe that an aggressive approach to diagnostic laparoscopy may produce cost-effective solutions to old and new intraabdominal problems.

Adult↗