Nasotracheal intubation: a randomized trial of two methods.

BACKGROUND: Several techniques have been suggested to reduce the trauma of nasotracheal intubation, although no comparative studies exist. The authors evaluated red-rubber catheters as a guide to nasotracheal intubation. METHODS: Children presenting for elective surgery were randomized to undergo red-rubber catheter-guided nasotracheal intubation or to have the nasotracheal tube alone inserted. After general anesthesia and paralysis with vecuronium, the nares were prepared with topical vasoconstrictor. The nasotracheal tube was softened with warm water. In the catheter-guided group, the nasotracheal tube tip was fitted to the trailing end of the red-rubber catheter, and the two were advanced together. The red-rubber catheter was retrieved from the nasopharynx, disconnected, and removed. In the other group, the nasotracheal tube was advanced blindly into the nasopharynx. In both groups, intubation was then completed during direct laryngoscopy using Magill forceps. A blinded observer swabbed the pharynx and rated the severity of bleeding based on reference photographs. RESULTS: Age, weight, snoring history, and difficulty of intubation were not different between groups. Obvious bleeding was lower using the red-rubber catheter technique (10 vs. 29%, P = 0.013), which took longer to perform (74 vs. 56 s, P = 0.02). CONCLUSIONS: Although the incidence of bleeding in both groups was similar, severity of bleeding was reduced in the catheter-guided group during nasotracheal intubation. Use of a red-rubber catheter may reduce the trauma associated with nasotracheal intubation.     

Effects of exchanging 4%en between dietary stearic and palmitic acid on hamster plasma lipoprotein metabolism

This study was designed to determine whether the exchange of specific fatty acids (palmitic (16 : 0) for stearic (18 : 0)), would exert differential effects on plasma and lipoprotein lipids, when diets contained ~30%en from fat with adequate levels of linoleic acid (18 : 2). Thirty-two male Golden Syrian hamsters were fed isocaloric purified diets with comparable amounts of 18 : 2 (~10.5%en). The 18 : 0-rich diet (50% cocoa butter, 41% safflower oil, 9% sunflower oil) provided 4.8%en 16 : 0 and 5.3%en from 18 : 0, while the 16 : 0-rich diet (59% palm oil, 36% safflower oil, 5% olive oil) provided 8.7%en from 16 : 0 and 1.2%en from 18 : 0, resulting in a 16 : 0/18 : 0 exchange of ~4%en. Both diets contained negligible amounts of lauric and myristic acid (<0.2%en), ~9.5%en from oleic acid and 77 mg cholesterol/1000 kcal. Animals were fed their respective diets for 4 weeks at which point various lipid and lipoprotein parameters were meassured. There were no significant difference between dietary groups for any of the measured parameters, which included body weights, food consumption, plasma lipids, lipoprotein lipid and apoprotein concentrations, as well as lipoprotein compositions. Additionally, estimated diameters of various lipoprotein particles were not affected by the fatty acid exchanges employed. Thus these data suggest that when total fat is restricted to 30%en and 18 : 2 levels are ~10%en, a 4%en exchange between 16 : 0 and 18 : 0 (representing intakes of ~9 g/d/2000 kcal diet) produces comparable plasma lipids.     

Aggressive hydration during continuous positive-pressure ventilation restores atrial transmural pressure, plasma atrial natriuretic peptide concentrations, and renal function.

BACKGROUND AND METHODS: The correlations between continuous positive-pressure ventilation-induced antidiuresis/antinatriuresis, atrial transmural pressure, and atrial natriuretic peptide concentrations have not been clarified. The purpose of the present study was to use aggressive hydration to restore atrial transmural pressure during continuous positive-pressure ventilation and to test for correlations of atrial transmural pressure, atrial natriuretic peptide concentration, diuresis, and natriuresis during this intervention. An intrapleural catheter was used to measure atrial transmural pressure in three ways: a) right atrial pressure minus intrapleural pressure, b) left ventricular end-diastolic pressure minus intrapleural pressure, and c) pulmonary artery occlusion pressure minus intrapleural pressure. Hemodynamic, atrial natriuretic peptide concentrations, and renal measurements were made in 12 anesthetized closed-chest dogs during baseline (intermittent positive-pressure ventilation), during continuous positive-pressure ventilation), during continuous positive-pressure ventilation with 10 cm H2O end-expiratory pressure, and during continuous positive-pressure ventilation plus aggressive hydration (approximately 60 mL/kg lactated Ringer's solution). Pearson's correlation matrix was used to generate all possible correlation coefficients between the three atrial transmural pressures, atrial natriuretic peptide concentrations, urine output, and urine sodium excretion. RESULTS: Application of continuous positive-pressure ventilation resulted in a 60% decrease in right atrial transmural pressure (p less than .05), a 51% decrease in left ventricular end-diastolic transmural pressure (p less than .05), and a 26% decrease in pulmonary artery occlusion transmural pressure (p less than .05) from baseline. Plasma atrial natriuretic peptide concentration decreased from 80 +/- 12 (SEM) pg/mL at baseline to 49 +/- 8 pg/mL during continuous positive-pressure ventilation (p less than .05). Both urine output and sodium excretion decreased by 81% (p less than .05). After aggressive hydration with lactated Ringer's solution during continuous positive-pressure ventilation, to restore atrial transmural pressure to baseline, plasma atrial natriuretic peptide concentration returned to baseline values (81 +/- 12 pg/mL) as did urine output and sodium excretion. Correlation indices (r2 values) between transmural pressure, atrial natriuretic peptide concentration, urine output, and sodium excretion ranged from .835 to .994. Multivariate analysis of covariance demonstrated significant (p less than .05) temporal dependence between the three transmural pressures, atrial natriuretic peptide concentration, urine output, and sodium excretion. CONCLUSIONS: The results demonstrate that aggressive hydration during continuous positive-pressure ventilation will restore diuresis and natriuresis and that this response correlates significantly with atrial transmural filling pressure and plasma atrial natriuretic peptide concentration.     

Polymorphs and hydrates of acyclovir

Acyclovir (ACV) has been commonly used as an antiviral for decades. Although the crystal structure of the commercial form, a 3:2 ACV/water solvate, has been known since 1980s, investigation into the structure of anhydrous ACV has been limited. Here, we report the characterization of four anhydrous forms of ACV and a new hydrate in addition to the known hydrate. Two of the anhydrous forms appear as small needles and are stable to air exposure, whereas the third form is morphologically similar but quickly absorbs water from the atmosphere and converts back to the commercial form. The high-temperature modification is achieved by heating anhydrous form I above 180 °C. The crystal structures of anhydrous form I and a novel hydrate are reported for the first time.     

John Cunningham virus T‐antigen expression in anal carcinoma

BACKGROUND:

Anal carcinoma is thought to be driven by human papillomavirus (HPV) infection through interrupting function of cell regulatory proteins such as p53 and pRb. John Cunningham virus (JCV) expresses a T‐antigen that causes malignant transformation through development of aneuploidy and interaction with some of the same regulatory proteins as HPV. JCV T‐antigen is present in brain, gastric, and colon malignancies, but has not been evaluated in anal cancers. The authors examined a cohort of anal cancers for JCV T‐antigen and correlated this with clinicopathologic data.

METHODS:

Archived anal carcinomas were analyzed for JCV T‐antigen expression. DNA from tumor and normal tissue was sequenced for JCV with viral copies determined by quantitative polymerase chain reaction and Southern blotting. HPV and microsatellite instability (MSI) status was correlated with JCV T‐antigen expression.

RESULTS:

Of 21 cases of anal cancer (mean age 49 years, 38% female), 12 (57%) were in human immunodeficiency virus (HIV)‐positive individuals. All 21 cancers expressed JCV T‐antigen, including 9 HPV‐negative specimens. More JCV copies were present in cancer versus surrounding normal tissue (mean 32.54 copies/μg DNA vs 2.98 copies/μg DNA, P = .0267). There was no correlation between disease stage and viral copies, nor between viral copies and HIV‐positive or ‐negative status (28.7 vs 36.34 copies/μg DNA, respectively, P = .7804). In subset analysis, no association was found between JCV T‐antigen expression and HPV or MSI status.

CONCLUSIONS:

Anal carcinomas uniformly express JCV T‐antigen and contain more viral copies compared with surrounding normal tissue. JCV and its T‐antigen oncogenic protein, presumably through interruption of cell regulatory proteins, may play a role in anal cancer pathogenesis. Cancer 2011. © 2010 American Cancer Society.     

Performance measures of surgeon-performed colonoscopy in a Veterans Affairs medical center

Background

Quality indicators are increasingly emphasized in the performance of colonoscopy. This study aimed to determine the standard of care rendered by surgeon-endoscopists in a Veterans Affairs (VA) medical center by evaluating the indications for colonoscopy and outcome performance measures according to established quality indicators for colonoscopy.

Methods

A prospective standardized computer endoscopic reporting database (ProVation MD) was retrospectively reviewed. All colonoscopies performed by attending surgeons at the San Diego VA medical center between 1 January 2004 and 31 July 2007 were included in the study. Patients with charts that had incomplete reporting were excluded. The quality indicators used included the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) criteria for colorectal cancer screening, the American Cancer Society (ACS) guidelines for postcancer resection surveillance, and the American Society of Gastrointestinal Endoscopists (ASGE) quality indicators for colonoscopy.

Results

The data for 558 patients (96% men) were analyzed. The average patient age was 63 years (range, 25–93 years). Almost all the colonoscopies (99%) were performed in accordance with established criteria. The most common indications for colonoscopy were screening (n = 143, 26%), non-acute gastrointestinal bleeding (n = 127, 23%), polyp surveillance (n = 100, 18%), postcancer resection surveillance (n = 91, 17%), abdominal pain (n = 19, 4%), and anemia (n = 14, 3%). Postcancer resection surveillance colonoscopies were performed according to recommended criteria in 98% of the cases. The cecal intubation rate was 97%, and the overall adenoma detection rate was 26%. Two patients (<1%) experienced complications requiring intervention.

Conclusion

The study data indicate that surgeon-performed colonoscopies meet standard quality criteria for indications and performance measures. The authors therefore conclude that surgeon-endoscopists demonstrate proficiency in the standard of care for colonoscopy examinations.     

Dysregulation of dopamine transporter trafficking and function after abstinence from cocaine self-administration in rats: evidence for differential regulation in caudate putamen and nucleus accumbens

The profound alterations produced by cocaine on dopamine (DA) neurotransmission raise the possibility that dopamine transporter (DAT)-expressing neurons may modify DA transport in response to repeated cocaine exposure to maintain the appropriate efficiency of DA clearance. In this study, we determined the changes in molecular mechanisms of DAT regulation in rats with a history of repeated cocaine self-administration followed by 3 weeks of abstinence. Using ex vivo caudate putamen (CPu) and nucleus accumbens (NAcc) synaptosomal preparations, we found that DA uptake was significantly higher in the CPu and NAcc of cocaine-experienced animals compared with yoked saline animals. Surface distribution, p-Ser phosphorylation, and protein phosphatase 2A catalytic subunit (PP2Ac) interaction of DAT were all altered in the CPu. Maximal velocity (V(max)) values were elevated both in the CPu and NAcc of cocaine-experienced rats compared with saline controls. Although there was no change in the apparent affinity for DA in the CPu, increased DA affinity was evident in the NAcc. Consistent with elevated DAT activity in cocaine-experienced animals, a higher level of surface DAT, DAT-PP2Ac association, and decreased serine phosphorylation of DAT were observed in the CPu, but not in the NAcc. These results, for the first time, suggest that chronic cocaine self-administration followed by abstinence leads to persisting alterations in normal DAT trafficking and catalytic regulatory cascades in the CPu and NAcc in a brain region-specific manner.     

Hybrid natural orifice translumenal surgery (NOTES) sleeve gastrectomy: a feasibility study using an animal model

Background  The indications for natural orifice translumenal surgery (NOTES) are yet to be determined. Morbidly obese patients may be one population that would benefit from this approach due to the elimination of wound complications and possibly a faster recovery. As a bariatric restrictive procedure, sleeve gastrectomy could be one indication for NOTES. To test the feasibility of this procedure with a NOTES approach, a pig model was used. Methods  Acute studies investigated five 40-kg farm pigs. The rectum was used as the port of entry to the peritoneal cavity, and the stomach was manipulated endoluminally using a gastroscope. Vision was acquired through a 5-mm laparoscope introduced transabdominally (i.e. via the hybrid technique). A 10-mm incision was made on the anterior wall of the rectum and dilated to accommodate a 12-mm trocar introduced through the rectal wall into the peritoneal cavity. The greater curvature of the stomach then was divided and detached, starting from the antrum and proceeding to the esophagogastric junction using a laparoscopic stapler. The sleeve gastrectomy was completed by dividing the short gastric vessels with an ultrasonic scalpel. The gastric pouch then was removed through the rectal incision. Results  A NOTES gastric sleeve resection was successfully performed in all five pigs. The technique was developed, and feasibility was determined. After resection, the gastric remnant was inflated, with no evidence of leakage. At autopsy, intact suture lines were noted. Closure of the rectal incision was not attempted. Conclusion  A NOTES sleeve gastrectomy is feasible in porcine animal models. The rectal port of entry allows rigid laparoscopic instruments to be introduced into the peritoneal cavity and enables performance of gastrointestinal procedures the same as in standard laparoscopic surgery. Extra-long instruments are necessary for dissection and division of the stomach at the esophagogastric junction and for accessing the short gastric vessels.