bluuebunny/crossref_metadata_2025_split huggingface dataset:
Resistance to d-Tubocurarine of the Rat Diaphragm as Compared to a Limb Muscle
Authors: Nguyen-Huu Tu , Molgó Jordi , Servent Denis , Duvaldestin Philippe 
Published: May 2009

Background
The diaphragm is resistant to competitive neuromuscular blocking agents, as compared to peripheral muscles. The basis of this difference may be a higher concentration of acetylcholine released or higher number of postsynaptic nicotinic acetylcholine receptors in diaphragmatic neuromuscular junctions.

Methods
Nerve-evoked twitch-tension was measured in rat hemidiaphragm as was Extensor digitorum longus (EDL) nerve-muscle preparation to determine the effective D-tubocurarine concentration that decreased twitch responses by 50%. The mean quantal content of endplate potentials was determined in single junctions in a low-Ca(2+), high-Mg(2+) Krebs-Ringer medium. Strips of hemidiaphragm and EDL muscle, containing the endplate regions, were used to determine the number of nAChR nicotinic acetylcholine receptor binding sites with the aid of radiolabeled [(125)I]alpha-bungarotoxin.

Results
The effective D-tubocurarine concentration that decreased twitch responses by 50% (median [interquartile range]) was seven-fold higher in the hemidiaphragm than in the EDL (1.82 microm [1.43-2.20] vs. 0.26 microm [0.23-0.29], P < 0.01). The median of the mean quantal content was higher in the hemidiaphragm than in the EDL (0.57 [0.44-0.84] vs. (0.14 [0.11-0.19], P < 0.01). The number of specific [(125)I]alpha-bungarotoxin binding sites to junctional nicotinic acetylcholine receptors was higher in the diaphragm than in the EDL (1.15 fmol/mg [0.48-1.70] vs. 0.55 fmol/mg [0.23-0.70 ], P < 0.05).

Conclusion
The current study indicates that the resistance of the diaphragm to neuromuscular blocking agents can be explained by both a higher mean quantal content of endplate potentials and a higher number of nicotinic acetylcholine receptor binding sites than in the peripheral EDL muscle.
Preoperative Electrocardiograms
Authors: Correll Darin J. , Hepner David L. , Chang Candace , Tsen Lawrence , Hevelone Nathanael D. , Bader Angela M. 
Published: May 2009

Background
Age is often the sole criterion for determining the need for preoperative electrocardiograms. However, screening electrocardiograms have not been shown to add value above clinical information. This study was designed to determine whether it is possible to target electrocardiograms ordering to patients most likely to have an abnormality that would affect management and if age alone is predictive of significant electrocardiograms abnormalities.

Methods
A list was developed of electrocardiograms abnormalities considered significant enough to impact management, as well as a list of patient factors believed to increase cardiovascular risk. electrocardiograms in all patients over 50 yr of age presenting for preoperative evaluation during a 2-month period were reviewed.

Results
A total of 1,149 electrocardiograms were reviewed, with 89 patients (7.8%) having at least one significant abnormality. These patients were compared with a group of 195 patients who had electrocardiograms that did not contain significant abnormalities. Patients at higher risk of having a significantly abnormal electrocardiograms that would potentially affect management were those older than 65 yr of age or who had a history of heart failure, high cholesterol, angina, myocardial infarction, or severe valvular disease. Five patients (0.44%) had an abnormal electrocardiograms in the absence of risk factors. The sensitivity of the model is 87.6%.

Conclusion
Age greater than 65 yr remains an independent predictor for significant preoperative electrocardiograms abnormalities. The specific clinical risk factors that were found have a high sensitivity and identified all but 0.44% of patients with electrocardiograms abnormalities that may affect preoperative management.
Amitriptyline Suppresses Neuroinflammation-dependent Interleukin-10-p38 Mitogen-activated Protein Kinase-Heme Oxygenase-1 Signaling Pathway in Chronic Morphine-infused Rats
Authors: Tai Yueh-Hua , Tsai Ru-Yin , Lin Shinn-Long , Yeh Chun-Chang , Wang Jhi-Joung , Tao Pao-Luh , Wong Chih-Shung 
Published: May 2009

Background
This study explores the underlying mechanism of the antiinflammatory effect of amitriptyline in chronic morphine-infused rats.

Methods
Male Wistar rats were implanted with two intrathecal catheters. One catheter was for the continuous infusion of saline, amitriptyline (15 microg/h), morphine (15 microg/h), p38 mitogen-activated protein kinase inhibitor SB203580 (0.5 microg/h), morphine plus amitriptyline, or morphine plus amitriptyline plus SB203580 for 5 days. The other catheter was used for daily intrathecal injection of anti-interleukin-10 (IL-10) antibody or heme oxygenase-1 inhibitor zinc protoporphyrin for 5 days.

Results
Amitriptyline/morphine coinfusion upregulated IL-10 protein expression in microglia; this was not observed in morphine-infused rats. Anti-IL-10 antibody effectively neutralized the amitriptyline-induced IL-10 expression in chronic morphine-infused rats. In addition, coinfusion of amitriptyline restored the antinociceptive effect of morphine (a 4.8-fold right-shift of the morphine dose-response curve compared to a 77.8-fold right-shift in its absence), and the injection of anti-IL-10 antibody or coinfusion of SB203580 partially reversed the effect of amitriptyline on the antinociceptive effect of morphine in morphine-infused rats (a 17.9-fold and 15.1-fold right-shift in morphine dose-response curves). Anti-IL-10 antibody and SB203580 significantly inhibited the amitriptyline-induced p38 mitogen-activated protein kinase and heme oxygenase-1 expression and the associated antiinflammatory effect of amitriptyline. Daily injection of zinc protoporphyrin also demonstrated that it reverses the effect of amitriptyline in morphine's antinociception and antiinflammation in chronic morphine-infused rats.

Conclusions
These results suggest that the antiinflammatory effect of amitriptyline on morphine tolerance, probably acting by increasing IL-10 expression, is mediated by p38 mitogen-activated protein kinase heme oxygenase-1 signal transduction cascade.
Continuous Perioperative Insulin Infusion Decreases Major Cardiovascular Events in Patients Undergoing Vascular Surgery
Authors: Subramaniam Balachundhar , Panzica Peter J. , Novack Victor , Mahmood Feroze , Matyal Robina , Mitchell John D. , Sundar Eswar , Bose Ruma , Pomposelli Frank , Kersten Judy R. , Talmor Daniel S. 
Published: May 2009

Background
A growing body of evidence suggests that hyperglycemia is an independent predictor of increased cardiovascular risk. Aggressive glycemic control in the intensive care decreases mortality. The benefit of glycemic control in noncardiac surgery is unknown.

Methods
In a single-center, prospective, unblinded, active-control study, 236 patients were randomly assigned to continuous insulin infusion (target glucose 100-150 mg/dl) or to a standard intermittent insulin bolus (treat glucose > 150 mg/dl) in patients undergoing peripheral vascular bypass, abdominal aortic aneurysm repair, or below- or above-knee amputation. The treatments began at the start of surgery and continued for 48 h. The primary endpoint was a composite of all-cause death, myocardial infarction, and acute congestive heart failure. The secondary endpoints were blood glucose concentrations, rates of hypoglycemia (< 60 mg/dl) and hyperglycemia (> 150 mg/dl), graft failure or reintervention, wound infection, acute renal insufficiency, and duration of stay.

Results
The groups were well balanced for baseline characteristics, except for older age in the intervention group. There was a significant reduction in primary endpoint (3.5%) in the intervention group compared with the control group (12.3%) (relative risk, 0.29; 95% confidence interval, 0.10-0.83; P = 0.013). The secondary endpoints were similar. Hypoglycemia occurred in 8.8% of the intervention group compared with 4.1% of the control group (P = 0.14). Multivariate analysis demonstrated that continuous insulin infusion was a negative independent predictor (odds ratio, 0.28; 95% confidence interval, 0.09-0.87; P = 0.027), whereas previous coronary artery disease was a positive predictor of adverse events.

Conclusion
Continuous insulin infusion reduces perioperative myocardial infarction after vascular surgery.
Computer-based Finite Element Modeling of Insulated Tuohy Needles Used in Regional Anesthesia
Authors: Cantrell Meredith B. , Grill Warren M. , Klein Stephen M. 
Published: May 2009

Background
Differences in needle design may impact nerve localization. This study evaluates the electrical properties of two insulated Tuohy needles using computational finite element modeling.

Methods
Three-dimensional geometric computer-based models were created representing two 18-gauge, insulated Tuohy needles: (1) with an exposed metal tip and (2) with an insulated tip. The models were projected in simulated human tissue. Using finite element methodology, distributions of current-density were calculated. Voltages in the modeled medium were calculated, and activation patterns of a model nerve fiber around the tip of each needle were estimated using the activating function.

Results
Maximum current density on the exposed-tip needle occurred along the edge of the distal tip; the distal edge was 1.7 times larger than the side edges and 3.5 times larger than the proximal edge. Conversely, maximum current density occurred along the proximal edge of the insulated-tip Tuohy opening; the proximal edge was 1.9 times larger than the side edges of the opening and 3.5 times larger than the distal edge of the opening. Voltages generated by the exposed-tip needle were larger and had a wider spatial distribution than that of the insulated-tip needle, which restricted to the area immediately adjacent to the opening. Different changes in threshold were predicted to excite a nerve fiber as the needles were rotated or advanced toward the modeled nerve.

Conclusions
The needles displayed different asymmetric distributions of current density and positional effects on threshold. If this analysis is validated clinically, it may prove useful in testing stimulating needles before clinical application.
Pentobarbital Dose-dependently Increases Respiratory Genioglossus Muscle Activity while Impairing Diaphragmatic Function in Anesthetized Rats
Authors: Eikermann Matthias , Fassbender Philipp , Zaremba Sebastian , Jordan Amy S. , Rosow Carl , Malhotra Atul , Chamberlin Nancy L. 
Published: May 2009

Background
Anesthetics depress both ventilatory and upper airway dilator muscle activity and thus put the upper airway at risk for collapse. However, these effects are agent-dependent and may involve upper airway and diaphragm muscles to varying degrees. The authors assessed the effects of pentobarbital on upper airway dilator and respiratory pump muscle function in rats and compared these results with the effects of normal sleep.

Methods
Tracheostomized rats were given increasing doses of pentobarbital to produce deep sedation then light and deep anesthesia, and negative pressure airway stimuli were applied (n = 11). To compare the effects of pentobarbital with those of natural sleep, the authors chronically instrumented rats (n = 10) with genioglossus and neck electromyogram and electroencephalogram electrodes and compared genioglossus activity during wakefulness, sleep (rapid eye movement and non-rapid eye movement), and pentobarbital anesthesia.

Results
Pentobarbital caused a dose-dependent decrease in ventilation and in phasic diaphragmatic electromyogram by 11 +/- 0.1%, but it increased phasic genioglossus electromyogram by 23 +/- 0.2%. Natural non-rapid eye movement sleep and pentobarbital anesthesia (10 mg/kg intraperitoneally) decreased respiratory genioglossus electromyogram by 61 +/- 29% and 45 +/- 35%, respectively, and natural rapid eye movement sleep caused the greatest decrease in phasic genioglossus electromyogram (95 +/- 0.3%).

Conclusions
Pentobarbital in rats impairs respiratory genioglossus activity compared to the awake state, but the decrease is no greater than seen during natural sleep. During anesthesia, in the absence of pharyngeal airflow, phasic genioglossus activity is increased in a dose-dependent fashion.
A Model for Understanding the Impacts of Demand and Capacity on Waiting Time to Enter a Congested Recovery Room
Authors: Schoenmeyr Tor , Dunn Peter F. , Gamarnik David , Levi Retsef , Berger David L. , Daily Bethany J. , Levine Wilton C. , Sandberg Warren S. 
Published: May 2009

Background
When a recovery room is fully occupied, patients frequently wait in the operating room after emerging from anesthesia. The frequency and duration of such delays depend on operating room case volume, average recovery time, and recovery room capacity.

Methods
The authors developed a simple yet nontrivial queueing model to predict the dynamics among the operating and recovery rooms as a function of the number of recovery beds, surgery case volume, recovery time, and other parameters. They hypothesized that the model could predict the observed distribution of patients in recovery and on waitlists, and they used statistical goodness-of-fit methods to test this hypothesis against data from their hospital. Numerical simulations and a survey were used to better understand the applicability of the model assumptions in other hospitals.

Results
Statistical tests cannot reject the prediction, and the model assumptions and predictions are in agreement with data. The survey and simulations suggest that the model is likely to be applicable at other hospitals. Small changes in capacity, such as addition of three beds (roughly 10% of capacity) are predicted to reduce waiting for recovery beds by approximately 60%. Conversely, even modest caseload increases could dramatically increase waiting.

Conclusions
A key managerial insight is that there is a sensitive relationship among caseload and number of recovery beds and the magnitude of recovery congestion. This is typical in highly utilized systems. The queueing approach is useful because it enables the investigation of future scenarios for which historical data are not directly applicable.
Changes in Functional Residual Capacity and Lung Mechanics during Surgical Repair of Congenital Heart Diseases
Authors: von Ungern-Sternberg Britta S. , Petak Ferenc , Hantos Zoltan , Habre Walid 
Published: May 2009

Background
To characterize the impact of lung volume changes in the lung function impairment after the surgical repair of congenital heart diseases, combined measurements of functional residual capacity, lung clearance index, and respiratory mechanics were performed in children with hypoperfused lungs (tetralogy of Fallot [TOF]) or with pulmonary hyperperfusion (ventricular septal defect [VSD]).

Methods
Lung volume and clearance were assessed by using a sulfur hexafluoride washout technique, and the mechanical properties of the respiratory system were assessed using a low-frequency oscillation technique. Lung volume and oscillatory measurements were made preoperatively, before and after cardiopulmonary bypass and aortic clamping (AC), and after chest closure.

Results
Impairments in airway (36 +/- 2%) and tissue mechanics (22 +/- 3%) were observed in the children with TOF after bypass; AC and chest closure were associated with marked decreases in functional residual capacity (-24 +/- 3% and -13 +/- 2% for TOF and VSD after AC, respectively) and increases in lung clearance index (-60 +/- 6% and -24 +/- 3% for TOF and VSD after AC, respectively). Smaller impairments in lung mechanics were observed after bypass and AC in children with VSD.

Conclusions
These findings suggest that the lung volume loss and lung mechanical deteriorations are probably caused by a diminished tethering effect of the lung periphery through a reduced filling of the pulmonary capillaries. This effect seems to be more pronounced in children with hypoperfused lungs (TOF) than in those with pulmonary hyperperfusion (VSD). The beneficial postoperative changes in children with VSD are consequences of the reversal of the pulmonary vascular engorgement after surgical repair.
Off-Pump Coronary Artery Bypass Grafting is Associated with Reduced Operative Mortality and In-Hospital Adverse Events in Patients with Left Main Coronary Artery Disease
Authors: Sarin Eric L. , Puskas John D. , Kilgo Patrick D. , Thourani Vinod H. , Guyton Robert A. , Lattouf Omar M. 
Published: May 2009

Objective Left main coronary artery disease (LMD) is a known risk factor for perioperative complications. This study compares off-pump coronary artery bypass (OPCAB) versus on-pump coronary artery bypass (ONCAB) grafting, CABG, with respect to in-hospital death, stroke, myocardial infarction, and major adverse cardiac events (MACE) in CABG patients with and without LMD. Methods Among 13,108 consecutive isolated patients with CABG treated from 1997 to 2007, 2891 patients (22.1%) were preoperatively found to have LMD. Of 5917 patients with OPCAB, 1276 (21.6%) had LMD, whereas among patients with ONCAB, 1615 of 7191 (22.5%) had LMD. Surgery type, LMD, and their interaction were examined for their impact on operative mortality, stroke, myocardial infarction, and MACE via multiple logistic regression models and adjusted odds ratios (AOR). Results Utilization of OPCAB for coronary revascularization in patients with LMD disease gradually increased from an initial low of 1.3% of patients in 1997 to a peak of 80.8% in 2007. OPCAB was associated with reduced incidence of stroke (AOR = 0.51, P < 0.001) and MACE (AOR = 0.66, P = 0.002), whereas LMD was associated with an increased incidence of MACE (AOR = 1.24, P = 0.038). No interactions between surgery type and LMD existed, meaning that the 2 conditions did not combine in any way to modify outcomes. Conclusions Patients with LMD are more likely to suffer a MACE event than those without LMD. Off-pump coronary artery bypass grafting is marginally associated with lesser risk of operative mortality and significantly associated with less stroke and overall MACE when compared with ONCAB. This benefit of OPCAB is similar for patients with and without LMD.
Clinical Characteristics and VPS33B Mutations in Patients With ARC Syndrome
Authors: Jang Joo Young , Kim Kyung Mo , Kim Gu‐Hwan , Yu Eunsil , Lee Jin‐Joo , Park Young Seo , Yoo Han‐Wook 
Published: May 2009

ABSTRACTObjectives:ARC (arthrogryposis, renal dysfunction, and cholestasis) syndrome is a rare, fatal cause of neonatal intrahepatic cholestasis without known treatment modalities and has recently been ascribed to a mutation in the VPS33B gene. We assessed the clinical characteristics and investigated the VPS33B mutations in Korean patients with ARC syndrome.Patients and Methods:We reviewed the medical records of 6 patients with ARC syndrome among 90 patients with neonatal cholestasis from 2000 to 2005 and assessed the relative incidence rate ratio, clinical symptoms, laboratory findings, and pathological findings. DNA samples from 5 patients, 4 parents, and 2 fetuses were analyzed for VPS33B mutations.Results:The relative incidence rate ratio was 1/7 that of biliary atresia (95% CI 0.33–0.06). All 6 patients presented with ichthyosis and recurrent infection, and failed to thrive with the 3 main symptoms. All of the patients died within the age of 12 months. They had various severities of cholestasis, metabolic acidosis, nephrogenic diabetes insipidus, chronic diarrhea, platelet abnormalities, and central nervous system anomalies. We identified 1 novel c.403+2T>A splice‐site mutation, 2 frame‐shift mutations (c.1509_1510insG, c.790_791del), 1 nonsense mutation (c.661C>A), and 1 known nonsense mutation (c.1518C>T) in the VPS33B gene. Prenatal diagnosis was performed in 2 different families.Conclusions:This study indicates that the incidence of ARC syndrome is not as rare as has been thought. We found 4 novel and 1 known mutations in ARC syndrome patients and performed prenatal diagnosis in 2 families, which will facilitate genetic diagnosis and counseling for affected families.
Follow‐up and Surgical Management of Peutz‐Jeghers Syndrome in Children
Authors: Vidal Isabelle , Podevin Guillaume , Piloquet Hugues , Le Rhun Marc , Frémond Benjamin , Aubert Didier , Leclair Marc‐David , Héloury Yves 
Published: May 2009

ABSTRACTBackground:Peutz‐Jeghers syndrome (PJS) is an autosomal dominant syndrome with an increased risk of polyposis complications and intestinal and extraintestinal tumours.Methods:During the last 15 years, we reviewed a series of 11 children with PJS, with special attention to evolution and follow‐up. Diagnosis was based on at least 1 hamartomatous polyp associated with 2 of the 3 following criteria: family record of PJS, polyposis localised on small bowel, and mucocutaneous pigmentation. Diagnosis of PJS also could be raised by a single genetic analysis of STK11 gene.Results:Median age at beginning of symptoms was 6 years old. Seven of the 11 children had genetic tests, which were positive for STK11 gene mutation. Among the 10 children presenting with gastrointestinal complications, 8 were operated on, 6 had at least 1 small bowel resection, and 4 had repeat surgery for recurrent intussusceptions. In case of complications leading to a surgical procedure, we performed intraoperative enteroscopy to remove all large polyps. To prevent any polyposis complications, we suggest a complete check‐up of polyposis topography with some of the new endoscopic tools, either double‐balloon endoscopy or videocapsule endoscopy.Conclusions:Children with PJS have a high risk of numerous laparotomies due to polyps' complications. Therefore, a screening of intestinal polyposis by videocapsule endoscopy is recommended, as well as a screening of the most frequent sites of cancers for the patient's whole life. During any abdominal procedure, they should have an intraoperative endoscopy, this management allowing an increased time interval between 2 laparotomies.
Gastrointestinal Norovirus Infection Associated With Exacerbation of Inflammatory Bowel Disease
Authors: Khan Raheel R , Lawson April D , Minnich Linda L , Martin Kathleen , Nasir Amana , Emmett Mary K , Welch Christine A , Udall John N 
Published: May 2009

ABSTRACTObjective:In this study we aimed to determine, in pediatric patients, whether norovirus infection could be associated with exacerbations of inflammatory bowel disease (IBD) and ascertain whether the clinical expression of norovirus gastroenteritis was similar in patients with IBD compared with non‐IBD controls.Materials and Methods:We performed a case‐control retrospective chart review, over a 10‐month interval, of patients with IBD with an exacerbation of their disease. The presence of norovirus in stool and/or rectal swab samples, as determined by an enzyme‐linked immunoassay, was assessed. In addition, sex, age, type of IBD, presence or absence of diarrhea, hematochezia, and the need for hospitalization were determined. A similar number of control patients who did not have IBD were used as controls.Results:Nine patients with IBD (8 ulcerative colitis/1 Crohn disease) had exacerbations with diarrhea. Eight had norovirus antigen in at least 1 sample. All 9 patients with IBD presented with bloody diarrhea and 6 of the 8 norovirus‐positive patients with IBD required hospitalization. All of the control patients experienced diarrhea; however, no hematochezia was noted and no hospitalization was required. Several patients with IBD and controls remained positive for norovirus months after the initial positive stool and/or rectal swab sample. The virus appeared to be more common during winter months.Conclusions:We conclude that norovirus may be associated with exacerbations of IBD. When norovirus accompanies IBD it is more likely to be associated with hematochezia than when the infection occurs in the absence of IBD.