Search

A ball-tip holmium laser fiber (TracTip; Boston Scientific) has been developed to theoretically reduce damaging friction forces generated within a ureteroscope working channel. We compared the insertional forces and damage with a ureteroscope inner lining when inserting standard flat-tip and ball-tip laser fibers.A standard ureteroscope channel liner was placed in a 3D-printed plastic mold. Molds were created at four angles of deflection (30°, 45°, 90°, and 180°) with a 1 cm radius of curvature. New 200 μm ball-tip (TracTip; Boston Scientific) and 200 μm flat-tip (Flexiva; Boston Scientific) laser fibers were advanced through the liner using a stage controller. A strain gauge was used to measure force required for insertion. Each fiber was passed 600 times at each angle of deflection. The ureteroscope liner was changed every 150 passes. Leak testing was performed every 50 passes or when the insertional force increased significantly to assess damage to the liner.At all deflection angles, the average insertional force was significantly lower with the ball-tip laser fibers compared with flat-tip laser fibers (p 0.001). All trials with the ball-tip lasers were completed at each angle without any leaks. Two of four trials using flat-tip fibers at 45° deflection caused liner leaks (at 91 and 114 passes). At 90° deflection, all flat-tip trials caused liner leaks on first pass. The 180° trials could not physically be completed with the flat-tip laser fiber. Within the flat- and ball-tip groups, an increasing amount of force was needed to pass the fiber as the degree of deflection increased (p 0.001).The ball-tip holmium laser fiber can be safely passed through a deflected ureteroscope without causing liner perforation. The standard flat-tip fiber requires greater insertion force at all angles and can cause the ureteroscope liner to leak if it is deflected 45° or more.

Urolithiasis, the formation or presence of calculi in the urinary tract, is a broad term covering a multifaceted disease process with wide-ranging clinical and economic implications. Stones, often originating in the renal papillae, may be found from the renal parenchyma through the renal pelvis, ureter, or bladder. Stones can be composed of a multitude of molecules either in pure form or mixtures of several compounds. Historically considered a disease of adults, the prevalence of stones has increased among children. This review highlights pathophysiology of urolithiasis, common clinical presentations, work-up, and surgical and medical management of this increasingly common pediatric condition. The authors review the chemical pathways by which stones form, common stone types, common operative techniques, and epidemiology. This review contains 4 tables, and 59 references. Key Words: extracorporeal shockwave lithotripsy, kidney stones, lithotripsy, nephrolithiasis, percutaneous nephrolithotomy, pediatrics, renal calculi, ureteroscopy, urolithiasis

I first visited Bhutan in the fall of 2011 to study the modernization the country was going through as a result of recent political changes. The king had stepped down as the political leader and a ...

Context Acromegaly is characterized by growth hormone (GH) and insulinlike growth factor-1 (IGF-1) hypersecretion, and GH and IGF-1 play important roles in regulating body composition and glucose homeostasis. Objective The purpose of our study was to investigate body composition including ectopic lipids, measures of glucose homeostasis, and gonadal steroids in patients with active acromegaly compared with age-, body mass index (BMI)−, and sex-matched controls and to determine changes in these parameters after biochemical control of acromegaly. Design Cross-sectional study of 20 patients with active acromegaly and 20 healthy matched controls. Prospective study of 16 patients before and after biochemical control of acromegaly. Main Outcome Measures Body composition including ectopic lipids by magnetic resonance imaging/proton magnetic resonance spectroscopy; measures of glucose homeostasis by an oral glucose tolerance test; gonadal steroids. Results Patients with active acromegaly had lower mean intrahepatic lipid (IHL) and higher mean fasting insulin and insulin area under the curve (AUC) values than controls. Men with acromegaly had lower mean total testosterone, sex hormone−binding globulin, and estradiol values than male controls. After therapy, homeostasis model assessment of insulin resistance, fasting insulin level, and insulin AUC decreased despite an increase in IHL and abdominal and thigh adipose tissues and a decrease in muscle mass. Conclusions Patients with acromegaly were characterized by insulin resistance and hyperinsulinemia but lower IHL compared with age-, BMI-, and sex-matched healthy controls. Biochemical control of acromegaly improved insulin resistance but led to a less favorable anthropometric phenotype with increased IHL and abdominal adiposity and decreased muscle mass.

BACKGROUND This study uses publicly available data to analyze the total number of elective, potentially deferrable operative procedures involving infants

To identify longitudinal trends of economic impact and resource utilization for management of pediatric urolithiasis using national databases.We analyzed the 2006-2012 Nationwide Emergency Department Sample and Nationwide Inpatient Sample. We used ICD-9 (International Classification of Diseases) codes to identify patients (≤18 years) diagnosed with urolithiasis. Diagnostic imaging and surgeries were identified using ICD-9 and Current Procedural Technology codes. We abstracted demographic, imaging, procedure, and charge data. Weighted descriptive statistics were calculated to describe the population's demographics and economic expenditures by clinical setting and year.In total, 45,333 inpatient admissions (68% females) and 234,559 emergency department encounters (63% females) were identified. Most patients (84%) were teenagers and the southern region of the United States was the most common geographic region for all encounters (44%). There was no significant trend in number of urolithiasis encounters over the period studied. Utilization of all imaging techniques increased; in particular, computed tomography was used in 23% of encounters in 2006 and 40% in 2012 (P .0001). The mean charge per emergency department visit increased by 60% from $3645 in 2006 to $5827 in 2012 (P .0001). The mean charge increased for inpatient admissions by 102%, from $16,399 in 2006 to $33,205 in 2012 (P .0001). Total charges increased 72% over the study period from $230 million in 2006 to $395 million in 2012 (P .0001), outpacing medical inflation over the same period.Charges for pediatric urolithiasis management increased by 65% from 2006 to 2012 despite stable frequency of patient encounters. The utilization of computerized tomography in pediatric urolithiasis increased as well.

Increased case volumes and training are associated with better surgical outcomes. However, the impact of pediatric urology sub-specialization on perioperative complication rates is unknown.To determine the presence and magnitude of difference in rates of common postoperative complications for elective pediatric urology procedures between specialization levels of urologic surgeons. The Nationwide Inpatient Sample (NIS), a nationally representative administrative database, was used.The NIS (1998-2009) was retrospectively reviewed for pediatric (≤18 years) admissions, using ICD-9-CM codes to identify urologic surgeries and National Surgical Quality Improvement Program (NSQIP) inpatient postoperative complications. Degree of pediatric sub-specialization was calculated using a Pediatric Proportion Index (PPI), defined as the ratio of children to total patients operated on by each provider. The providers were grouped into PPI quartiles: Q1, 0-25% specialization; Q2, 25-50%; Q3, 50-75%; Q4, 75-100%. Weighted multivariate analysis was performed to test for associations between PPI and surgical complications.A total of 71,479 weighted inpatient admissions were identified. Patient age decreased with increasing specialization: Q1, 7.9 vs Q2, 4.8 vs Q3, 4.8 vs Q4, 4.6 years, P 0.01). Specialization was not associated with race (P 0.20), gender (P 0.50), or comorbidity scores (P = 0.10). Mortality (1.5% vs 0.2% vs 0.3% vs 0.4%, P 0.01) and complication rates (15.5% vs 11.7% vs 9.6% vs 10.9%, P 0.0001) both decreased with increasing specialization. Patients treated by more highly specialized surgeons incurred slightly higher costs (Q2, +4%; Q3, +1%; Q4 + 2%) but experienced shorter length of hospital stay (Q2, -5%; Q3, -10%; Q4, -3%) compared with the least specialized providers. A greater proportion of patients treated by Q1 and Q3 specialized urologists had CCS ≥2 than those seen by Q2 or Q4 urologists (12.5% and 12.2%, respectively vs 8.4% and 10.9%, respectively, P = 0.04). Adjusting for confounding effects, increased pediatric specialization was associated with decreased postoperative complications: Q2 OR 0.78, CI 0.58-1.05; Q3 OR 0.60, CI 0.44-0.84; Q4 OR 0.70, CI 0.58-0.84; P 0.01.Providers with proportionally higher volumes of pediatric patients achieved better postoperative outcomes than their less sub-specialized counterparts. This may have arisen from increased exposure to pediatric anatomy and physiology, and greater familiarity with pediatric techniques.The NIS admission-based retrospective design did not enable assessment of long-term outcomes, repeated admissions, or to track a particular patient across time. The study was similarly limited in evaluating the effect of pre-surgical referral patterns on patient distributions.Increased pediatric sub-specialization among urologists was associated with a decreased risk of mortality and surgical complications in children undergoing inpatient urologic procedures.

Pregnancy and lactation are accompanied by behavioral changes that include altered responses to stress. Previous exposure to a stressor can also modulate subsequent stress-related behavior, and this effect is at least partly mediated by the reproductive hormone, estrogen. In this study, we sought to determine if the stress-related behavior of rats that had been exposed to a cat would vary with reproductive status. After exposure to a cat or a nonstress control procedure, pregnant, lactating, virgin female or male rats received two acoustic startle test sessions on consecutive days, followed 4 days later by testing on an elevated plus maze. Startle amplitudes tended to increase across trials in all groups, but were differentially enhanced in nonstressed pregnant and lactating rats. A 5-min exposure to a cat eliminated the enhanced responding in these two groups. The cat exposure attenuated startle stimulus-evoked freezing only in the pregnant rats and produced differential plus maze performance in this group. Cat exposure produced no differential effects in virgin females or males. These results suggest that reproductive state can influence the impact of a stressor on subsequent behavior, but does so in a rather complex way.

Minimally invasive surgery (MIS) techniques are anecdotally reported to be increasingly used, but little objective data supports this. Our objective was to assess trends in MIS utilization across various procedures in pediatric urology and to compare postoperative complication rates between MIS and open procedures.We analyzed the 1998-2012 Nationwide Inpatient Sample. We identified children (18 years old) undergoing open and MIS inpatient procedures and any in-hospital post-operative complications that occurred during that postoperative hospitalization. We utilized propensity score matching and multivariable logistic regression to adjust for confounding factors.We identified 163,838 weighted encounters in the "overall cohort," 70,273 of which were at centers performing more than five MIS procedures over the years studied. Use of MIS techniques increased significantly over time for several procedures, most prominently for nephrectomy (Fig.). The overall rate of complications was lower in patients undergoing MIS compared with open surgery (6% vs. 11%, p 0.001). Specialized centers had a significantly lower overall rate of complications than unspecialized centers (9% vs. 12%, p 0.001). Within specialized centers, MIS had lower complication rates than open procedures (7% vs. 9%, p 0.001); this finding was consistent even after adjusting for other factors (OR 0.71, p = 0.02).Limitations include that these data may not be generalizable to encounters not in the sample pool. As a large, retrospective, administrative database, NIS may be affected by miscoding bias - rendering our analysis sensitive to the accuracy of procedure coding in NIS. Although the accuracy level of NIS is high for an administrative database, it is possible at least some portion of our cohort may be incorrectly coded. Further, the NSQIP complications we identified may represent associated comorbidities and not true postoperative complications, as NIS does not provide temporal relationships between different diagnosis codes. Despite these limitations, we note that the NIS database is rigorously monitored and audited for coding accuracy and, therefore, represents a reasonably reliable panorama of the characteristics of an inpatient surgical cohort. However, it is important to note that the choice of operative modality is, undoubtedly, multifactorial and patient/setting-specific.There is increasing use of MIS for pediatric urology procedures, although utilization rates vary among procedures. MIS was associated with a lower postoperative complication rate than for open procedures. Higher-volume MIS centers have a lower complication rate than lower-volume centers.

Objectives: The mechanisms responsible for the development of nonalcoholic fatty liver disease (NAFLD) and progression to nonalcoholic steatohepatitis (NASH) are incompletely understood. Growing evidence suggests that growth hormone (GH) and insulin-like growth factor-1 (IGF-1) may have roles in the development and progression of NAFLD. We hypothesized that lower serum IGF-1 levels would be associated with increased liver fat accumulation, inflammation, and fibrosis in a group of meticulously phenotyped obese subjects with liver biopsies. Methods: A retrospective, cross-sectional study was performed at Massachusetts General Hospital, Boston, MA, USA and St. Mary's Hospital, Richmond, VA, USA. Liver biopsies were performed in 142 subjects during NAFLD work-up or bariatric surgery and were graded by a single, blinded pathologist. Main outcome measures included liver histology and serum IGF-1. Results: Mean age was 52±10 years and body mass index (BMI) was 43±9 kg/m2. Mean serum IGF-1 was lower in subjects with lobular inflammation (112±47 vs. 136±57 ng/ml, P=0.01), hepatocyte ballooning (115±48 vs. 135±57 ng/ml, P=0.05), higher fibrosis stage (stage 2–4 vs. 0–1; 96±40 vs. 125±51 ng/ml, P=0.005), and NASH (109±45 vs. 136±57 ng/ml, P=0.002). All results remained significant after controlling for age, BMI, and a diagnosis of diabetes, and all but hepatocyte ballooning (trend, P=0.06) remained significant after excluding individuals with cirrhosis. Steatosis was not significantly associated with mean serum IGF-1 levels. Conclusions: Low serum IGF-1 levels are associated with increased histologic severity of NAFLD when rigorously controlled for age, BMI, the presence of diabetes, and after the exclusion of subjects with cirrhosis. Further investigation is warranted to determine the differential effects of GH and IGF-1 on the development and progression of NAFLD, which could further elucidate pathophysiology and identify therapeutic targets.

This 15-year-old White female was admitted with a 7-10 day history of high fever, joint pain, and increasing shortness of breath. Her illness began 10 days prior to admission (PTA) with fever to 105°F and severe throat pain associated with blisters in the posterior oropharynx and what was thought to be enlarged right anterior cervical lymph nodes causing neck pain. She was seen in the acute care clinic at Disney World, Orlando, Florida, where she and her father were vacationing. A strep screen and heterophile antibody test were negative. She was discharged with symptomatic treatment. Over the next 2 days she had continued fever, an increasingly painful cough, pleuritic chest pain with dyspnea, watery diarrhea, decreased appetite, and intermittent abdominal pain. Seven days PTA she experienced right hip, right shoulder, and left knee pain. When her dyspnea increased, she was seen in the emergency department where a chest x-ray revealed a nodular pneumonia pattern. On admission she was unable to walk because of her hip pain and had moderate respiratory distress. Her temperature was 101.9°F, pulse 142 beats per minute, respirations 64 breaths per minute, blood pressure 101/57 mm Hg, and pulse oximetry 85% on room air. Tonsils were enlarged but there was no exudate. There was a slight fullness palpable from the right submandibular area to the mid neck. Exam of the heart was normal. There were decreased breath sounds at both lung bases. There was diffuse, poorly characterized pain around the right shoulder and right hip without appreciable joint effusion or increased pain on internal rotation. The rest of the physical exam was unremarkable.

The tail flick withdrawal reflex (TFR) was generated by applying graded electric current to the tail of intact and spinally transected rats. In Experiment 1, separate groups of rats were tested 1, 3, 7, 10, 14, or 21 days after spinal transection. The latency, amplitude, and magnitude of the TFR was highly related to current intensity in both intact and spinal animals. However, the TFR changed dramatically as a function of the number of days between spinalization and TFR measurement. Compared to intact controls, the current intensity at which TFR was initiated (threshold) in spinal rats was elevated 1 and 3 days after transection, did not differ at 7 and 10 days, and was reduced at 14 and 21 days. Latency of TFR in spinal rats did not differ from controls 1 day after transection, but decreased steadily thereafter. Amplitude and magnitude of TFR in spinal rats remained depressed, but did show recovery toward control levels as the interval between transection and testing increased. Changes in the TFR of spinal rats was correlated with recovery of tailpinch-elicited hindlimb withdrawal. Experiment 2 demonstrated that the dose-response curve relating systemic morphine treatment to increases in TFR thresholds was shifted to the right in chronic spinal rats. Threshold increases in both spinal and intact rats were not necessarily accompanied by changes in TFR performance. These experiments establish the segmental organization of tailshock-elicited TFR and supports its use as a measure of nociceptive transmission at spinal levels.

Marked increases in anxiety-like responses to stress occur during pregnancy. Considerable evidence indicates that the basolateral region of the amygdala (BLA) plays an important role in mediating these types of responses. Given the crucial inhibitory influence of GABA on excitatory glutamatergic activity in the BLA, we hypothesized that decreased GABAergic activity in this region may underlie the increased anxiety associated with pregnancy. In vivo microdialysis was used to sample extracellular GABA before and after 30 min of restraint stress. While there was no detectable effect of restraint on extracellular GABA concentrations, basal GABA levels were significantly decreased in pregnant rats compared with either virgin females or males. We suggest that the alterations in anxiety-like behavior that occur during pregnancy may be associated with decreased basal GABA in the BLA.

Atrial fibrillation (AF) is the most common sustained arrhythmia after cardiac surgery. Postoperative AF is known to substantially lengthen hospital stay and affect patient recovery. Identification of those at risk of developing AF after surgery and early detection of AF during recovery would be extremely helpful in effective management of these patients, including targeting prophylactic therapy to prevent AF in high-risk patients. In this communication, diagnostic methods to identify those at risk of developing AF after surgery and early identification of AF before, during, and after surgery have been reviewed. Signal-averaged P wave analysis, done before surgery, identifies patients who are likely to develop AF during recovery. When combined with low ejection fraction, signal-averaged P wave can discriminate those who develop AF from those who do not. During recovery, AF can be detected early either from a detailed analysis of atrial activity in a 10-second electrocardiogram or an analysis of R-to-R intervals from an extended rhythm strip (1 minute or longer). Analysis of the 10-second electrocardiogram includes median QRST subtraction from rhythm data and detection and analysis of atrial signals in the resulting residual. AF is detected from extended rhythm strips by using a statistical model to identify the presence of characteristic irregular patterns of R-to-R intervals.

Ruptured intracranial aneurysms are the usual cause of acute subarachnoid hemorrhage (SAH). Noncontrast CT is the primary imaging procedure of choice for establishing the diagnosis of SAH. Conventional contrast angiography is the gold standard for establishing the presence of intracranial aneurysms, but CT and MRI have supplementary roles. The pathogenesis, presentation, and imaging of SAH and intracranial aneurysms are discussed.

The observation of hippocampal place cells forms a major line of evidence supporting the view that the hippocampus is dedicated to spatial processing. However, most studies demonstrating the spatial properties of hippocampal unit activity have employed tasks that emphasize spatial cues but minimize nonspatial cues. In the present experiment we recorded the activity of hippocampal complex-spike cells from rats performing a nonspatial radial maze task. Performance in this task was guided by local visual-tactile cues on the maze arms, while distal spatial cues were minimized and made irrelevant. The influence of three variables on unit activity was examined:type of cue on an arm, spatial location of an arm, and the relative position of the animal on an arm. Of the units recorded, almost one-fifth were classified as “cue cells” in that their activity was associated with cue type but not spatial location. Conversely, a similar proportion of the units were classified as “place cells” in that their activity was associated with location, but not cue type. In an additional similar proportion of units, firing was influenced only by relative position and not by local cues or spatial locations. For the majority of units, however, firing was related to combinations of these three variables, indicating that most hippocampal neurons encoded conjunctions or relations between spatial and local cue information. This pattern of results indicates that when local rather than distal spatial cues are emphasized, hippocampal neural activity is strongly influenced by salient nonspatial cues and shows no overwhelming predominance of place coding. These findings are at odds with the hypothesis that the hippocampus is selectively involved in spatial processing and, conversely, support the broader view that the hippocampus encodes both spatial and nonspatial relations among important experimental variables.

Two experiments were conducted to examine the effects of the anxiolytic drug, diazepam, on long-term habituation of the acoustic startle response. The experiments were based upon the hypothesis that manipulations that reduce fear should enhance long-term response decrements by reducing a fear-like sensitization process. In experiment 1 rats given intraperitoneal injections of 0.5, 1.2, or 2.5 mg/kg showed larger decrements of startle amplitude than vehicle-injected controls both over trials within sessions and over days. In Experiment 2 rats injected with 35 μg of diazepam bilaterally into the amygdala showed larger decrements of startle amplitudes over days than vehicle-injected controls. No within-session startle effects were detected in Experiment 2. Freezing behavior was measured in Experiment 2 as an index of fear, and the amygdala injections of diazepam retarded the development of fear in the startle chamber. This index of fear was not possible in Experiment 1 because of the sedating effects of systemic diazepam. We conclude that diazepam, acting at least in part through the amygdala, attenuates the fear-like sensitization process associated with the acoustic startle stimulus. By attenuating sensitization diazepam produces larger than normal reductions in startle amplitudes over trials and days without significantly affecting initial responsiveness.

Young interprets codification as part of a larger process that included the collapse of the Lower Canadian rebellions, the decline of seigneurialism, expansion of bourgeois democracy in central Canada, professionalization of the bar, and formation of the institutional state. Central to codification was a profound ideological shift in Lower Canadian society that gave priority to exchange and individual property rights. Young examines the evolution of codification from its nationalist origins in the 1820s and 1830s into a Civil Code that was integral to Confederation and became a flagship of bilingualism in Quebec. The formation of the commission, the work of the codifiers, and the reaction of the anglophone minority and the Roman Catholic hierarchy are considered, as is the Code's meticulous blending of a conservative social vision with the principles of freedom of property. The Politics of Codification will be of great interest to students of law, members of the legal professions, and Canadian social and legal historians.

The paper reports eight experiments concerning the form class effect. If verb connectives enhance organization between pairs of nouns more than do conjunction connectives, then (a) the form class effect should obtain in cued but not free recall, (b) interactive imagery instructions should raise performance with conjunctions, removing the effect, (c) separation imagery instructions should reduce performance with verbs, removing the effect, and (d) prepositions implying spatial contact should be superior as mediators for cued recall compared with less suggestive prepositions. The results of the experiments confirm the predictions, except that grade 3 children do not perform as expected with the instructional variables.