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A perchlorotriarylmethyl tricarboxylic acid radical 99% enriched in 13 C at the central carbon ( 13 C 1 -PTMTC) was characterized in phosphate buffered saline solution (pH = 7.2) (PBS) at ambient temperature. Samples immobilized in 1:1 PBS:glycerol or in 9:1 trehalose:sucrose were studied as a function of temperature. Isotope enrichment at C 1 creates a trityl that can be used to accurately measure microscopic viscosity. Understanding of the impact of the 13 C hyperfine interaction on electron spin relaxation is important for application of this trityl in oximetry and distance measurements. The anisotropic 13 C 1 hyperfine couplings (A x = A y = 24 ± 2 MHz, A z = 200 ± 1 MHz) are larger than for the related 13 C 1 -perdeuterated Finland trityl ( 13 C 1 -dFT) and the g anisotropy (g x = 2.0013, g y = 2.0016, g z = 2.0042) is slightly larger than for 13 C 1 -dFT. The tumbling correlation times (τ R ) for 13 C 1 -PTMTC are 0.20 ± 0.02 ns in PBS and 0.40 ± 0.05 ns in 3:1 PBS:glycerol, which are shorter than for 13 C 1 -dFT in the same solutions. T 1 for 13 C 1 -PTMTC is 3.5 ± 0.5 μs in PBS and 5.3 ± 0.4 μs in 3:1 PBS:glycerol, which are shorter than for 13 C 1 -dFT due to faster tumbling, larger anisotropy of the 13 C 1 hyperfine, and about 30% larger contribution from the local mode. In immobilized samples T 1 for 13 C 1 -PTMTC is similar to that for 13 C 1 -dFT and other trityls without chlorine or 13 C 1 substituents, indicating that the 13 C 1 and Cl substituents on the phenyl rings have little impact on T 1 . The temperature dependence of T 1 was modeled with contributions from the direct, Raman, and local mode processes. Broadening of CW linewidths of about 0.6 G in fluid solution and about 2 G in rigid lattice is attributed to unresolved 35,37 Cl hyperfine couplings.

Soluble stable radicals are used as spin probes and spin labels for in vitro and in vivo electron paramagnetic resonance (EPR) spectroscopy and imaging applications. We report the synthesis and characterization of a perchlorinated triarylmethyl radical enriched 99% at the central carbon, 13 C 1 -PTMTC . The anisotropy of the hyperfine splitting with the 13 C 1 ( A x = 26, A y = 25, A z = 199.5 MHz) and the g ( g x = 2.0015, g y = 2.0015, g z = 2.0040) are responsible for a strong effect of the radical tumbling rate on the EPR spectrum. The rotational correlation time can be determined by spectral simulation or via the line width or the apparent A z after calibration, so the spin probe 13 C 1 -PTMTC can be used to measure media microviscosity with high sensitivity.

BACKGROUND Synthetic cannabinoids have a higher affinity for the cannabinoid receptors CB1 and CB2 than natural cannabinoids. Their use can be associated with cardiovascular disease and neurological complications. A case is reported of status epilepticus and stress cardiomyopathy following the recreational use of the synthetic cannabinoid, UR-144. CASE REPORT A 19-year-old woman presented to the emergency department in status epilepticus after smoking the synthetic cannabinoid known as 'space'. Recurring seizure activity was controlled after three hours. On hospital day 3, the patient developed severe biventricular failure. Cardiac magnetic resonance imaging (MRI) confirmed the diagnosis of stress cardiomyopathy. A comprehensive urine drug screen was performed using gas chromatography-mass spectrometry (GC-MS), which was positive for UR-144, or (1-pentyl-1H-indol-3-yl)(2,2,3,3-tetramethylcyclopropyl)-methanone, and negative for all other illicit recreational drugs. The patient improved at one week following admission, with a left ventricular ejection fraction (LVEF) of 40%. She was discharged home on hospital day 10. CONCLUSIONS The use of the synthetic cannabinoid, UR-144, may be associated with prolonged status epilepticus and stress cardiomyopathy. Physicians should be aware of these potentially lethal complications associated with the recreational use of this and other illicit synthetic cannabinoids.

We report the synthesis of hydroxyethyl tetrathiatriarylmethyl radical OX063 and its deuterated analogue OX071 for biomedical EPR applications., Competing Interests: Conflicts of interest There are no conflicts to declare.

Palliative care in itself has many challenges; these challenges are compounded exponentially when placed in the setting of a mass casualty event, such as the 2010 Haiti earthquake. Haiti itself was an austere environment with very little infrastructure before the disaster. US surgeons, intensivists, and nurses worked hand in hand with other international providers and Haitian volunteers to provide the best care for the many. Improvisation and teamwork as well as respect for the Haitian caregivers were crucial to their successes. Sisyphean trials lie ahead. Haiti and its people must not be forgotten., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Palliative care in itself has many challenges; these challenges are compounded exponentially when placed in the setting of a mass casualty event, such as the 2010 Haiti earthquake. Haiti itself was an austere environment with very little infrastructure before the disaster. US surgeons, intensivists, and nurses worked hand in hand with other international providers and Haitian volunteers to provide the best care for the many. Improvisation and teamwork as well as respect for the Haitian caregivers were crucial to their successes. Sisyphean trials lie ahead. Haiti and its people must not be forgotten., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Previous research has shown that skill focused attention may be beneficial for the performance of complicated motor tasks in individuals with Parkinson's disease (PD). The objective of this study was to assess the impact of skill focused attention instructions on gait under temporal movement constraints that may reflect common challenges experienced in daily life. Eighteen patients with PD walked a straight pathway under two different attention focus conditions (no instruction, skill focused instruction) and two different walking speeds (preferred pace, as fast as possible). In the no instruction condition, patients were not told "where" attention should be directed. In the skill focused instruction condition, patients were told to focus on the foot contacting the floor with each step. Spatial and temporal gait measures, as well as, trunk sway were used to quantify walking performance. The results showed that when walking at a preferred pace, skill focused instructions benefited gait performance (e.g., increased gait velocity, larger steps, more trunk sway). However, when walking as fast as possible, skill focused instructions had the opposite effect on gait performance (e.g., decreased gait velocity, smaller steps, and less trunk sway). This study demonstrates that skill focused instructions may contribute to the prioritization of stability under imposed temporal movement constraints. Clinicians should be aware of the processes involved in prioritization of movement components versus task goals in PD and the potential application of an attention based instructional set in altering priorities in this population., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Objective: On the path to picture naming, words that relate semantically to the pictured object become activated in the mental lexicon. We used a neuroscientific approach to investigate this semantic activation spreading process in adults who stutter (AWS)., Methods: Fourteen AWS and 14 adults who do not stutter (AWNS) completed a picture-word priming task. On each trial, a picture was named at a delay. On some trials, an unattended auditory probe word was presented after the picture, before naming commenced. Event-related potentials recorded to probe words Semantically-Related to the picture labels, and to probe words Semantically- and Phonologically-Unrelated to the picture labels, were compared using spatial-temporal principal component analysis., Results: Posterior N400 amplitude was attenuated for Semantically-Related versus Unrelated probes in AWNS, while in AWS posterior N400 amplitude was enhanced for Semantically-Related versus Unrelated probes. Marginal albeit potentially relevant group differences in the morphology of other ERP components were also observed., Conclusions: The posterior N400 results point to a strategic, inhibitory influence on semantic activation spreading in AWS on the path to naming. Group differences in the amplitude of other ERP components tentatively suggest that AWS allocated attentional resources differently than the AWNS during the task. Preliminary ERP evidence of intact conceptual (as opposed to lexical-semantic) priming in the AWS is also discussed., Significance: This study contributes to a growing body of research describing linguistic performance in AWS., (2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

Biofeedback has been shown to improve balance in a number of different populations. As certain clinical populations have a tendency to fall in one direction, the provision of biofeedback in the impaired direction may improve balance in that direction but not in others. The purpose of this study was to determine the effects of uni-directional biofeedback on stance tasks in healthy young adults. Trunk sway was measured in 40 healthy young adults as they performed nine stance tasks with and without biofeedback. Participants received biofeedback about their trunk sway in either the anterior-posterior (AP) or medial-lateral (ML) direction using a multi-modal head-mounted biofeedback device. An overall effect of reduced sway angle and increased sway angular velocity was noted with biofeedback. Some of the effects of biofeedback were dependent on the direction in which biofeedback was given and whether vision was present during the stance task. These effects were strongest in the pitch direction for AP biofeedback with vision present. This study showed direction specific effects of biofeedback are greatest in the sagittal plane. These results are important clinically as the use of biofeedback during stance tasks, similar to gait tasks, appears to work best in the AP direction when vision is present., (Copyright 2010 Elsevier B.V. All rights reserved.)

Although recognized for more than 150 years, acute acalculous cholecystitis (AAC) remains an elusive diagnosis. This is likely because of the complex clinical setting in which this entity develops, the lack of large prospective controlled trials that evaluate various diagnostic modalities, and thus dependence on a small data base for clinical decision making. AAC most often occurs in critically ill patients, especially related to trauma, surgery, shock, burns, sepsis, total parenteral nutrition, and/or prolonged fasting. Clinically, AAC is difficult to diagnose because the findings of right upper-quadrant pain, fever, leukocytosis, and abnormal liver tests are not specific. AAC is associated with a high mortality, but early diagnosis and intervention can change this. Early diagnosis is the crux of debate surrounding AAC, and it usually rests with imaging modalities. There are no specific criteria to diagnose AAC. Therefore, this review discusses the imaging methods most likely to arrive at an early and accurate diagnosis despite the complexities of the radiologic modalities. A pragmatic approach is vital. A timely diagnosis will depend on a high index of suspicion in the appropriate patient, and the combined results of clinical findings (admittedly nonspecific), plus properly interpreted imaging. Sonogram (often sequential) and hepatic iminodiacetic acid scans are the most reliable modalities for diagnosis. It is generally agreed that cholecystectomy is the definitive therapy for AAC. However, at times a diagnostic/therapeutic drainage via interventional radiology/surgery may be necessary and life-saving, and may be the only treatment needed., (Copyright (c) 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Although it is well established that postural threat modifies postural control, little is known regarding the underlying mechanism(s) responsible for these changes. It is possible that changes in postural control under conditions of elevated postural threat result from a shift to a more conscious control of posture. The purpose of this study was to determine the influence of elevated postural threat on conscious control of posture and to determine the relationship between conscious control and postural control measures. Forty-eight healthy young adults stood on a force plate at two different surface heights: ground level (LOW) and 3.2-m above ground level (HIGH). Centre of pressure measures calculated in the anterior-posterior (AP) direction were mean position (AP-MP), root mean square (AP-RMS) and mean power frequency (AP-MPF). A modified state-specific version of the Movement Specific Reinvestment Scale was used to measure conscious motor processing (CMP) and movement self-consciousness (MSC). Balance confidence, fear of falling, perceived stability, and perceived and actual anxiety indicators were also collected. A significant effect of postural threat was found for movement reinvestment as participants reported more conscious control and a greater concern about their posture at the HIGH height. Significant correlations between CMP and MSC with AP-MP were observed as participants who consciously controlled and were more concerned for their posture leaned further away from the platform edge. It is possible that changes in movement reinvestment can influence specific aspects of posture (leaning) but other aspects may be immune to these changes (amplitude and frequency).

BmrR is a member of the MerR family and a multidrug binding transcription factor that up-regulates the expression of the bmr multidrug efflux transporter gene in response to myriad lipophilic cationic compounds. The structural mechanism by which BmrR binds these chemically and structurally different drugs and subsequently activates transcription is poorly understood. Here, we describe the crystal structures of BmrR bound to rhodamine 6G (R6G) or berberine (Ber) and cognate DNA. These structures reveal each drug stacks against multiple aromatic residues with their positive charges most proximal to the carboxylate group of Glu-253 and that, unlike other multidrug binding pockets, that of BmrR is rigid. Substitution of Glu-253 with either alanine (E253A) or glutamine (E253Q) results in unpredictable binding affinities for R6G, Ber, and tetraphenylphosphonium. Moreover, these drug binding studies reveal that the negative charge of Glu-253 is not important for high affinity binding to Ber and tetraphenylphosphonium but plays a more significant, but unpredictable, role in R6G binding. In vitro transcription data show that E253A and E253Q are constitutively active, and structures of the drug-free E253A-DNA and E253Q-DNA complexes support a transcription activation mechanism requiring the expulsion of Tyr-152 from the multidrug binding pocket. In sum, these data delineate the mechanism by which BmrR binds lipophilic, monovalent cationic compounds and suggest the importance of the redundant negative electrostatic nature of this rigid drug binding pocket that can be used to discriminate against molecules that are not substrates of the Bmr multidrug efflux pump.

Characteristics of cognitive deficits in benign childhood epilepsy with centrotemporal spikes (BECTS) remain unclear. The authors screened 200 BECTS children presenting for a clinical trial, finding relative weaknesses in fine motor control, visual learning, and attention in the presence of overall normal intellect, with simple partial seizures associated with more difficulty. Parental concerns for psychosomatic and learning problems were noted. Monitoring select cognitive and behavioral features in BECTS appears appropriate.

The discoveries of nucleotide excision repair and transcription-coupled repair led by Phil Hanawalt and a few colleagues sparked a dramatic evolution in our understanding of DNA and molecular biology by revealing the intriguing systems of DNA repair essential to life. In fact, modifications of the cut-and-patch principles identified by Phil Hanawalt and colleagues underlie many of the common themes for the recognition and removal of damaged DNA bases outlined in this review. The emergence of these common themes and a unified understanding have been greatly aided from the direct visualizations of repair proteins and their interactions with damaged DNA by structural biology. These visualizations of DNA repair structures have complemented the increasing wealth of biochemical and genetic information on DNA base damage responses by revealing general themes for the recognition of damaged bases, such as sequence-independent DNA recognition motifs, minor groove reading heads for initial damage recognition, and nucleotide flipping from the major groove into active-site pockets for high specificity of base damage recognition and removal. We know that repair intermediates are as harmful as the initial damage itself, and that these intermediates are protected from one repair step to the next by the enzymes involved, such that pathway-specific handoffs must be efficiently coordinated. Here we focus on the structural biology of the repair enzymes and proteins that recognize specific base lesions and either initiate the base excision repair pathway or directly repair the damage in one step. This understanding of the molecular basis for DNA base integrity is fundamental to resolving key scientific, medical, and public health issues, including the evaluation of the risks from inherited repair protein mutations, environmental toxins, and medical procedures.

Objective: African Americans often report greater pain than do Caucasians, but the factors responsible for this discrepancy are not known. We examined whether alexithymia-the trait of difficulty identifying and describing one's feelings and lacking introspection-may contribute to this ethnic group difference. We tested whether the mean level of alexithymia is higher, and whether alexithymia and pain are more highly correlated, among African Americans than among Caucasians in patients with chronic pain disorders., Design: Three cross-sectional, correlational studies were conducted on three separate samples of patients with chronic pain. Analyses examined the full sample and then Caucasians and African Americans separately., Setting and Patients: Patients were recruited primarily from treatment settings. Samples were patients with rheumatoid arthritis (N = 155), migraine headaches (N = 160), or systemic lupus erythematosus (N = 123), and each sample included only Caucasians or African Americans., Measures: The Toronto Alexithymia Scale-20 assessed global alexithymia and three alexithymia facets. Pain severity, functional disability, or symptoms were also measured on each sample., Results: Similar findings occurred across all three samples. African Americans had only slightly higher mean alexithymia levels than did Caucasians, and this was partly accounted for by socioeconomic differences between groups. More importantly, alexithymia correlated only weakly with pain or symptom severity for each full sample, but the two ethnic groups showed different patterns. Alexithymia correlated positively with pain severity among African Americans, but was uncorrelated with pain among Caucasians, even after covarying for various socioeconomic variables., Conclusions: Alexithymia is more correlated with pain severity among African Americans with chronic pain disorders than among Caucasians, potentially contributing to the higher pain reports among African Americans.

All surgeons should maintain a lifetime commitment to education and learning. Those who already are in practice need to make the effort to obtain or refresh their education in basic competencies in palliative care and to provide a measured balance between philosophy and practical skills. Many resources and teaching tools are available to assist in this continuing process: surgical peers (and peers from other medical specialties),journals, textbooks, CME conferences, surgical governance and educational organizations, and palliative care websites. A tremendous summary article on palliative care education for surgeons was published recently in JACS[24]. Surgeons must be competent in the following palliative care skills:communication, holistic patient evaluation, control of pain and symptoms,understanding legal/ethical issues, withdrawing care, and the continuum of acute to chronic to terminal care. If they cannot attend to all of these areas individually, they need to be aware of the local, regional, and national resources that are available to assist the patient (or their surrogate decision maker) and themselves in the end-of-life arena. Consultations and referrals should be accomplished in such a manner that the patient does not feel abandoned by his/her surgeon at such a critical point in his/her life. Practicing surgeons also must be involved actively in the education of resident and medical students in didactic and clinical situations. Most importantly, they must model the appropriate behaviors for their charges personally, whether it be in the consultation room breaking bad news compassionately or at the bedside easing the path to the next world. In these golden hours, the educated surgeon who wields new and mighty resources can be the greatest champion of the patient who is at the end of life.

Objective: The validity of self-reported negative emotion to predict health status is limited by response biases, introspection limitations, and methodological confounds. The reports of significant others about the patients' negative emotion may circumvent these limitations. This study sought to compare the validity of self- versus other-reported negative emotion as a correlate of migraine headache activity., Methods: On 89 patients with migraine headache (74 women and 15 men), we correlated self-ratings and significant-other-ratings of patients' negative emotion with patients' report of migraine frequency and severity, which were assessed both cross-sectionally and prospectively, 3 months later., Results: Other-reported negative emotion correlated with migraine activity better than did self-reported negative emotion, both cross-sectionally and prospectively. Patterns were different for women and men, however. Among women, other-reported negative emotion was positively associated with migraine activity. Among men, other-reported negative emotion was inversely associated with migraine frequency and severity., Conclusion: The results suggest that it may be valuable to obtain significant-other-ratings when assessing negative emotion in patients and that the genders may differ in how others' ratings are related to the patients' health.

The discovery of the recA gene toward the middle of the 20th century sparked work in perhaps one of the most biochemically and biophysically intriguing systems of DNA repair-homologous recombination. The inner workings of this system, in particular those of the more complex eukaryotes, have been and in many ways remain mysterious. Yet at the turn of this century, a wealth of structural and genetic results has unveiled a detailed picture of the roles, relationships, and mechanics of interacting homologous recombination proteins. Here we focus on the predominant questions addressed by these exciting 21st century structural results-from detection of broken DNA ends to coordination of pathway progression. The emerging structural view of double-strand break repair, therefore, reveals the molecular basis both for functions specific to DNA recombination and for general features characterizing DNA repair processes.

Potentially mutagenic uracil-containing nucleotide intermediates are generated by deamination of dCTP, either spontaneously or enzymatically as the first step in the conversion of dCTP to dTTP. dUTPases convert dUTP to dUMP, thus avoiding the misincorporation of dUTP into DNA and creating the substrate for the next enzyme in the dTTP synthetic pathway, thymidylate synthase. Although dCTP deaminase and dUTPase activities are usually found in separate but homologous enzymes, the hyperthermophile Methanococcus jannaschii has an enzyme, DCD-DUT, that harbors both dCTP deaminase and dUTP pyrophosphatase activities. DCD-DUT has highest activity on dCTP, followed by dUTP, and dTTP inhibits both the deaminase and pyrophosphatase activities. To help clarify structure-function relationships for DCD-DUT, we have determined the crystal structure of the wild-type DCD-DUT protein in its apo form to 1.42A and structures of DCD-DUT in complex with dCTP and dUTP to resolutions of 1.77A and 2.10A, respectively. To gain insights into substrate interactions, we complemented analyses of the experimentally defined weak density for nucleotides with automated docking experiments using dCTP, dUTP, and dTTP. DCD-DUT is a hexamer, unlike the homologous dUTPases, and its subunits contain several insertions and substitutions different from the dUTPase beta barrel core that likely contribute to dCTP specificity and deamination. These first structures of a dCTP deaminase reveal a probable role for an unstructured C-terminal region different from that of the dUTPases and possible mechanisms for both bifunctional enzyme activity and feedback inhibition by dTTP.

Background: The efficacy and long-term results of endoscopic management of upper tract transitional cell carcinoma (TCC) were examined. The authors evaluated the accuracy of endoscopic biopsy in determining tumor grade in the subset of patients who underwent open surgical excision., Methods: Between 1987 and 2001, 50 patients (17 with a solitary kidney) underwent ureteroscopy and biopsy of upper tract TCC. Eleven patients underwent ureterectomy or nephroureterectomy shortly after endoscopic biopsy. There was no follow-up for nine patients. Thirty patients underwent endoscopic ablation of their primary tumor with laser or electrofulguration at the time of the initial biopsy and were followed with close endoscopic surveillance at 3-4-month intervals., Results: For the 30 patients who underwent endoscopic ablation, mean follow-up was 38 months (range, 4-106 months). There was an average of 3.4 recurrences, with an average time to first recurrence of 7 months. Ten of the 30 patients underwent open resection during follow-up. Six patients exhibited tumor progression at follow-up. During the follow-up period, one patient died of recurrent disease, and six died of other causes. Endoscopic biopsy accurately predicted the tumor grade for 8 of the 9 patients who had open tumor resection within 2 months of their last biopsy and for 10 of the 11 patients who had open resection shortly after their initial endoscopic biopsy (overall accuracy, 18 of 20 [90%])., Conclusions: Endoscopic treatment of focal low-grade TCC of the upper urinary tract is feasible and safe, provided that vigilant follow-up and endoscopic surveillance are performed. Endoscopic biopsy provides accurate information regarding tumor grade., (Copyright 2003 American Cancer Society.DOI 10.1002/cncr.11446)

Objectives: Childhood sleep-disordered breathing (SDB) has been associated with poor school performance. Both problems are common among African-American (AA) children, but potential confounders such as low socioeconomic status (SES) and obesity have not been well studied., Methods: Children in second and fifth grades at six urban elementary schools were evaluated by teachers' ratings and year-end reading and math assessments. Risk for SDB was assessed with the validated parental Pediatric Sleep Questionnaire, and SES by qualification for school lunch assistance., Results: Among 146 children whose parents completed surveys, risk for SDB was associated with AA race, low SES, and poor teacher ratings (P<0.01), but not assessment scores (P>0.1). In multiple regression models, poor school performance was consistently and independently predicted by low SES (P<0.01) but not by AA race or SDB risk. Risk for SDB was associated with low SES before, but not after body mass index (BMI) was taken into account., Conclusions: The SDB symptoms, AA race, and low SES all vary to some extent with poor school performance, but the only consistent and independent covariate of performance is SES. Risk for SDB is associated with low SES, perhaps because of a third variable, namely high BMI.

Over the past two years, the structures of many prokaryotic transcriptional regulators have been solved, and several of them have revealed the structural mechanism of gene regulation. The crystal structure of BmrR-TPP-DNA reveals a novel mechanism of transcription activation, whereby the drug-bound protein activates the bmr promoter by local DNA unwinding and base pair disruption. Myristoyl-CoA induces FadR by a three-helix pushing mechanism, whereas TetR employs a helical pendulum motion to regulate expression. The structures of AbrB, and DNA complexes of Rob and MuR unveil a novel DNA-binding motif, 'the looped-hinge helix', and new uses of the helix-turn-helix and winged helix motifs in DNA binding.

Purpose: Renal hemangioma is a rare clinical entity that is difficult to diagnose. In the past it was treated with partial or complete nephrectomy. However, in the age of minimally invasive procedures endoscopy has enabled more accurate diagnosis and management. We reviewed our experience with transurethral ureterorenoscopy using a flexible ureteroscope to determine the feasibility and success of endoscopic treatment of renal hemangioma., Materials and Methods: We reviewed the records of 15 patients with a mean age of 37.5 years who presented with recurrent lateralized gross hematuria and were diagnosed with renal hemangioma based on transurethral ureterorenoscopy using a flexible ureteroscope. Lesions were treated using a 2 or 3Fr electrocautery probe, or a 200 mu. laser fiber with holmium or neodymium:YAG energy., Results: Followup was 2 to 96 months (mean 20.2). Of the 15 cases 14 were successfully managed by endoscopy. A single patient initially treated with endoscopy in 1988 underwent partial nephrectomy shortly thereafter secondary to continued bleeding. No patient had any complication related to the procedure. All except 1 of the 12 patients on whom followup data were available remain free of any hematuria., Conclusions: When the source of unilateral hematuria is unknown or in doubt, particularly in young patients, the diagnosis of a hemangioma should be considered. Transurethral ureterorenoscopy using a flexible ureteroscope is an excellent method of visualizing the offending lesion and safely treating it using an electrocautery probe or laser fiber.

The crystal structures of corepressor-bound and free Escherichia coli purine repressor (PurR) have delineated the roles of several residues in corepressor binding and specificity and the intramolecular signal transduction (allosterism) of this LacI/GalR family member. From these structures, residue W147 was implicated as a key component of the allosteric response, but in many members of the LacI/GalR family, position 147 is occupied by an arginine. To understand the role of this tryptophan at position 147, three proteins, substituted by phenylalanine (W147F), alanine (W147A), or arginine (W147R), were constructed and characterized in vivo and in vitro, and their structures were determined. W147F displays a decreased affinity for corepressor and is a poor repressor in vivo. W147A and W147R, on the other hand, are super repressors and bind corepressor 13.6 and 7.9 times more tightly, respectively, than wild-type. Each mutant PurR-hypoxanthine-purF operator holo complex crystallizes isomorphously to wild-type. Whereas the apo corepressor binding domain (CBD) of W147F crystallizes under those conditions used for the wild-type protein, neither the apo CBD of W147R nor W147A crystallizes, although screened extensively for new crystal forms. Structures of the holo repressor mutants have been solved to resolutions between 2.5 and 2.9 A, and the structure of the apo CBD of W147F has been solved to 2.4 A resolution. These structures provide insight into the altered biochemical properties and physiological functions of these mutants, which appear to depend on the sometimes subtle preference for one conformation (apo vs holo) over the other.

The aryl hydrocarbon receptor nuclear transporter (ARNT) is a basic helix-loop-helix (bHLH) protein that contains a Per-Arnt-Sim (PAS) domain. ARNT heterodimerizes in vivo with other bHLH PAS proteins to regulate a number of cellular activities, but a physiological role for ARNT homodimers has not yet been established. Moreover, no rigorous studies have been done to characterize the biochemical properties of the bHLH domain of ARNT that would address this issue. To begin this characterization, we chemically synthesized a 56-residue peptide encompassing the bHLH domain of ARNT (residues 90-145). In the absence of DNA, the ARNT-bHLH peptide can form homodimers in lower ionic strength, as evidenced by dynamic light scattering analysis, and can bind E-box DNA (CACGTG) with high specificity and affinity, as determined by fluorescence anisotropy. Dimers and tetramers of ARNT-bHLH are observed bound to DNA in equilibrium sedimentation and dynamic light scattering experiments. The homodimeric peptide also undergoes a coil-to-helix transition upon E-box DNA binding. Peptide oligomerization and DNA affinity are strongly influenced by ionic strength. These biochemical and biophysical studies on the ARNT-bHLH reveal its inherent ability to form homodimers at concentrations supporting a physiological function and underscore the significant biochemical differences among the bHLH superfamily.

Purpose: The loin pain-hematuria syndrome is a well recognized but poorly understood clinical condition in which patients have progressive loin pain accompanied by hematuria but they maintain stable renal function. We present 2 cases effectively treated with renal autotransplantation, as well as a review of the literature, and a coherent algorithm for the diagnosis and treatment of this condition., Materials and Methods: The medical literature concerning the loin pain-hematuria syndrome was reviewed. In 1994 we performed renal autotransplantation on 2 patients with the loin pain-hematuria syndrome at our institution., Results: Extensive urological evaluation revealed no obvious underlying abnormalities in patients with the loin pain-hematuria syndrome. Theories for the pathogenesis of this condition range from thrombotic phenomena to autoimmune processes. Treatment efforts have been directed primarily towards pain management. Narcotic dependence becomes progressive as the pain becomes debilitating. In extreme cases nephrectomy is performed despite normal renal function. Several invasive methods of nerve block and enervation provide only temporary relief. Renal autotransplantation provided lasting cessation of loin pain in both of our patients with followup of 1.5 and 2.5 years, and this intervention has been shown to provide the most durable pain relief in other series., Conclusions: Renal autotransplantation provides the most durable, nonnarcotic, nephron sparing relief for patients with the loin pain-hematuria syndrome. Further investigation is necessary to elucidate the pathophysiology of this debilitating condition.

Leptomeningeal carcinomatosis is a rare and deceptive presentation of systemic cancer. We report the treatment of a patient with a Klatskin's tumor by surgical resection. The patient presented with symptoms suggestive of liver failure in the early postoperative period. He rapidly developed progressive, multineuroaxis symptoms and died. Routine gastrointestinal evaluation failed to demonstrate any intraabdominal pathologic process that could be responsible for his decline. A MRI of the brain was also unremarkable. Serial lumbar punctures, however, documented leptomeningeal carcinomatosis consistent with a gastrointestinal primary. The clinical presentation of leptomeningeal carcinomatosis is subtle and may masquerade as another disease state. The hallmark of this lethal process is the finding of progressive neurologic deficits at more than one level of the neuroaxis. Serial cerebrospinal fluid examination is often diagnostic. This is the first known report of leptomeningeal carcinomatosis secondary to primary cholangiocarcinoma.

Children have been slow to benefit from the improvements in stone therapy. Despite the success of less invasive techniques, open surgery for pediatric urolithiasis is still commonly practiced. The authors' goal was to evaluate the indications, efficacy, and complications of endourologic surgery in the treatment of pediatric urolithiasis. They reviewed the treatment of 53 children who had upper tract calculi. Open nephro- and ureterolithotomy were avoided in all cases. The management of 25 children whose stones were not amenable to extracorporeal shock wave lithotriopsy is presented. Seventeen children (19 stones) were treated with miniature ureteroscopes and lasertripsy. Only one (6%) of the patients required ureteral dilation, and only five (29%) needed a postoperative internal stent. Eight children with large renal calculi were treated percutaneously, without transfusion, complication, or evidence of persistent renal damage. All 25 patients were rendered stone-free. The hospital stay was shorter and secondary procedures were less common in comparison to other series of endoscopic lithotripsy. With significant experience in adult endourology and proper instrumentation, one can apply the same techniques to children and achieve equal if not greater benefit. Nephrolithiasis in children is uncommon and should be managed in an institution where endourologists and multiple treatment modalities are available.

Purpose: Since 1982 the Kock ileal reservoir has been the primary form of urinary diversion in patients requiring lower urinary tract reconstruction at our institution. The intussuscepted afferent nipple valve of the Kock ileal reservoir is designed to prevent reflux and protect the upper urinary tract. Problems associated specifically with the afferent antireflux valve have been few. We defined and characterized all complications associated with the Kock pouch antireflux nipple valve., Materials and Methods: From November 1984 through July 1992, 802 patients underwent construction of a continent Kock ileal reservoir. All complications associated with the afferent antireflux valve in this group and their management were identified., Results: Overall, 79 of 802 patients (9.8%) had a total of 84 complications of the afferent antireflux valve (10.4%), including formation of stones on staples securing the afferent nipple valve in 42 cases (5.2%), stenosis of the afferent valve in 35 (4.3%) and prolapse of the valve in 7 (0.9%). A total of 81 patients required surgical intervention to correct the afferent valve complication: 56 (7.0%) were treated endoscopically and 25 (3.1%) required open surgical revision., Conclusions: We report an overall complication rate of 10.4% associated with the afferent antireflux nipple valve in the Kock ileal reservoir. Most complications can be treated endoscopically without difficulty on an outpatient basis with the use of local sedation. With these results, and only a 3% incidence of open surgical correction of all afferent nipple problems, we encourage the continued use of the intussuscepted afferent nipple valve whenever continent urinary diversion is performed.

Neurofibromatosis (NF) is a common autosomal dominant disease characterized by the development of hamartomatous or neoplastic lesions due to the proliferation of neural crest cells. An association of aneurysmal arterial lesions with NF, which may have catastrophic complications, has been rarely reported. Our recent experiences with the diagnosis and management of three male NF patients with aneurysms is described. A 19-year-old-man with refractory hypertension due to unilateral, complex, unreconstructable renal artery aneurysms was successfully treated by nephrectomy. Histopathology demonstrated intramural renal artery Schwann cell proliferation. A 44-year-old patient underwent ligation of a ruptured superior mesenteric artery aneurysm. Finally, a femoral-popliteal artery saphenous vein bypass graft with aneurysm exclusion was performed in a 58-year-old-man with a 3.5 cm symptomatic popliteal artery aneurysm. In NF, the underlying pathology in large arteries is intramuscular Schwann cell proliferation with secondary fibrosis. Mesodermal dysplasia may affect small arteries resulting in stenosis, post-stenotic dilatation, or aneurysmal degeneration. Clinicians should be aware of the unusual association of NF with aneurysms, particularly the occult development of visceral and renal artery aneurysms. These lesions are subject to sudden rupture with potentially devastating consequences, and they mandate a high index of suspicion in NF patients.

The discovery of nucleated erythrocytes in maternal circulation provides a potential source for non-invasive prenatal diagnosis. We have evaluated the use of a three-stage procedure to determine the number of cells that are of fetal rather than maternal origin. First, monoclonal antibodies specific for CD45 and CD14 were used in conjunction with a magnetic (MACS) column to deplete unwanted leukocytes from maternal blood. This was followed by a positive MACS enrichment for nucleated erythrocytes, using an anti-CD71 (transferrin receptor) monoclonal antibody. To discriminate between fetal nucleated erythrocytes and those of maternal origin, enriched fractions were simultaneously stained with an anti-fetal haemoglobin (HbF) antibody and hybridized with probes specific for X and Y chromosomes. Samples were then subjected to blind analysis along with negative control samples from non-pregnant volunteers. Using this dual analysis, we were able to determine that less than one nucleated erythrocyte per ml of maternal blood was of fetal origin. Small numbers of these fetal cells were found in 87.5% of pregnancies, ranging from 6 to 35 weeks gestational age. Comparison of HbF and X/Y probe data also suggests that the fetal cells are less suitable for fluorescence in-situ hybridization (FISH) analysis than similar preparations from other sources.

Localized amyloidosis of the bladder is a rare cause of hematuria, which is often confused with bladder cancer. We present case histories of two patients which illustrate the evaluation and management of this entity. The diagnosis is usually made with biopsy and subsequent pathologic examination. Conservative management is attempted initially but must be individualized according to the clinical course of each patient. Transurethral resection will suffice in most instances but occasionally cystectomy is indicated to control local disease.

Between August 1982 and May 1988, 503 patients underwent construction of a continent ileal reservoir (Kock pouch) for cutaneous urinary diversion at our university. Stenosis of the afferent antireflux valve resulted in upper urinary tract obstruction in 11 patients (2%). In addition, 2 patients underwent Kock pouch diversion elsewhere and upon referral to our institution they had afferent valve stenosis. To date 13 patients have been identified with this problem. Hydronephrosis was present in 100% of the functional kidneys in these patients. Radiographs of the Kock pouch were uniformly normal without evidence of reflux or other pathological condition. The most common presenting symptom was flank pain in 7 patients (54%) and the most common presenting sign was creatinine elevation above baseline in 7 (54%). Infections recurred with or without sepsis in 5 patients (38%). Ureteroileal anastomotic strictures were not present in any patient. The interval from creation of the Kock pouch to the diagnosis of stenosis ranged from 2 to 75 months (mean 39). All patients underwent endoscopic evaluation of the Kock pouch confirming stenosis of the afferent antireflux valve, and subsequent mechanical dilation of the stenotic valve. Dilation procedures were repeated in 6 patients (46%), 4 of whom subsequently required open surgical revision of the afferent valve. Of these patients 3 are clinically stable and 1 died of the primary malignancy. The remaining 2 patients are clinically and radiographically stable after multiple dilations. Of the 7 patients (54%) requiring only a single dilation 6 are clinically stable and 1 died of the primary malignancy. Stenosis of the afferent antireflux valve of the Kock pouch, previously unreported to our knowledge, is a rare late complication leading to flank pain, hydronephrosis, recurrent infection and elevation of serum creatinine levels. Approximately 50% of the patients respond to a single dilation of the nipple valve. However, most patients who require repeat dilation will need open surgical revision.

The use of topical agents in the treatment and prophylaxis of transitional cell carcinoma of the bladder is well described. Several physicians have reported the use of these materials in the upper urinary tract for treatment of transitional cell carcinoma. We present our treatment protocol using mitomycin C as topical therapy following endoscopic resection of superficial urothelial tumors of the renal pelvis or ureter. A total of 7 patients was treated during the last 4 years. No systemic side effects due to perfusion with mitomycin C occurred. We believe that our treatment method provides a safe means of delivering topical agents to the upper urinary tract and suggest its use when such treatment is believed to be necessary.

Two spacer regions outside the ribosomal DNA (rDNA) transcriptional unit in three species of Saccharomyces, S. cerevisiae, S. carlsbergensis and S. pastorianus, were amplified using the polymerase chain reaction. These regions were composed of the 3' external transcribed spacer (ETS) and the intergenic spacer (IGS). Primers were developed from sequence alignments and by taking the reverse complement of a previously described sequence. The region amplified spanned base position 3110 on the 26S rRNA to base position 27 on the 5S rRNA of S. cerevisiae. Nine of the twelve strains used in this study exhibited different restriction profiles, showing that the spacers are highly variable between species. The results suggest that PCR fingerprinting of the non-coding spacer regions can be used to distinguish between closely related Saccharomyces species and may have potential in DNA profiling of other yeasts.

Iatrogenic ureteral injury, an uncommon entity, is primarily caused by complications of gynecologic surgery. This report describes a case of ureterovaginal fistula discovered 13 days after a vaginal hysterectomy. Ureteroscopy was performed, with passage of an indwelling ureteral stent for 6 weeks. The patient immediately became continent of urine and the fistula healed, thus avoiding the need for further surgery.

The Northgate SD-3 is a bathless, portable shock wave lithotriptor made in the United States. It uses ultrasound localization and spark-gap, electrode-generated shock waves to fragment calculi in the upper urinary tract. Since October 1987, 312 treatments have been performed on 281 patients (286 kidneys) with stone burdens less than 2 cm. during clinical trials at 6 investigational sites in the United States. A fragmentation rate of 94% was achieved. Of the treatments 78% were judged successful (stone-free or fragments of less than 5 mm. remaining in an asymptomatic patient) and a 3-month stone-free rate of 58% was noted. The retreatment rate was 9% and the ancillary procedure rate was 5%. The complications (hematuria, ecchymosis, pain, obstruction) were mild and not unlike those seen in patients undergoing lithotripsy with other devices.

The Kock pouch continent ileal reservoir has become a therapeutic option for those patients requiring urinary diversion. Complications of this procedure do occur but fortunately many of these may be managed endoscopically without need for open surgical exploration. This report describes experience with 55 patients treated by endoscopic surgery for complications of Kock pouch urinary diversion. This includes 45 patients with stones, 3 with stenotic afferent nipple valves, 3 with suspicion of ureteral or renal pelvic tumor, and 4 with retained upper urinary tract stents. These patients may be treated with intravenous sedation only on an outpatient basis. The procedure was successful in all but 2 patients. One complication occurred when extravasation was noted from the afferent limb. The patient was treated by internal diversion, and follow-up urogram done in forty-eight hours was normal. This experience confirms that endoscopic surgery is an attractive option for treatment of many of the complications resulting from creation of a Kock pouch ileal reservoir.

The long-term effects of extracorporeal shock wave lithotripsy (ESWL*) on children treated for renal calculi are unclear. To study the long-term bio-effects of this mode of treatment on the immature animal we evaluated 30 New Zealand white rabbits at 7 weeks of age for weight, serum blood urea nitrogen and creatinine, and arterial blood pressure after which they underwent left nephrectomy. Each group of 5 rabbits received ESWL of varying levels (500 to 3,000 shock waves) to the remaining right kidney using the Northgate SD3 lithotriptor (spark gap mediated). One control group received no shock waves. At maturity (16 weeks) the aforementioned parameters were measured again, and the kidneys and any grossly abnormal adjacent organs were examined. We found no significant change in total animal growth, renal growth, renal function or perirenal organs in the post-ESWL groups versus the control group. All post-ESWL groups had an increase in mean arterial blood pressure versus the control group with 3 of 6 groups showing significant increases (p less than 0.05). Histological renal changes, seen at all energy levels of ESWL delivered, included interstitial fibrosis, tubular atrophy, glomeruli destruction, capsular thickening, perivascular fibrosis and mild arteriole wall thickening. Changes were proportional to the number of shocks received. We conclude that ESWL delivered to immature animals does not significantly affect renal growth and function but it can cause significant permanent histological renal changes even at low doses and may result in an increase in adult mean arterial blood pressure.

Urinary tract stone disease has been found to be a later complication associated with the construction of the Kock pouch continent urinary diversion. Of 383 patients who underwent Kock pouch diversion between August 1982 and December 1986 stones developed in the pouch in 64 (16.7%), usually on exposed staples or eroded Marlex used to construct the nipple valves. Stones have recurred in 13 of the 64 patients (22%). Most stones were removed endoscopically with techniques similar to those used for percutaneous stone removal. Risk factors for stone formation include Marlex collar erosion and acute pyelonephritis. Changes in surgical techniques with elimination of the Marlex collar and a reduction in the number of staples have reduced the incidence of this later complication to 10%.

Indwelling self-retaining ureteral stents are important for the maintenance of urinary drainage in the ureter threatened by obstruction by neoplasm, edema, or calculus. Proximal migration of the stent into the ureter prevents simple cystoscopic retrieval and necessitates removal by other techniques. In this series both rigid and flexible ureteroscopes were used to remove stents from locations ranging from the renal pelvis to the distal ureter in 16 patients. Three-pronged wire graspers was the retrieval instrument most frequently used. Stents were removed in all patients without complication. Ureteroscopy provides the most convenient and least invasive technique for removing stents proximally located in the upper urinary system.

Microscopic chromocystoscopy is a new in vivo procedure that we have developed to aid in the detection and treatment of bladder tumors. Intravesical ionic dye chromocystoscopy was introduced by our group to permit cystoscopic viewing with ordinary light of selectively stained malignant urothelial surfaces by the cationic dye, methylene blue. With the recent availability of the Hamou hysteroscope, a microscopic endoscope, we have combined intravesical ionic dye chromocystoscopy with microscopic cystoscopy to give in vivo urothelial surface histology, with resolution of cytological detail. We herein describe our new method and preliminary results with this procedure, which we have designated in vivo urothelial surface histology by microscopic chromocystoscopy.

The use of topical chemotherapy for the treatment of upper urinary tract urothelial tumors and the selection of patients to receive this treatment remain problematic because of the relatively infrequent occurrence of these tumors compared with similar tumors within the bladder. The lack of clinicopathologic information on upper urinary tract urothelial tumors makes pretherapy diagnosis and clinical staging difficult. In addition, there are problems associated with delivery of the agent, and there is not as yet an effective method of surveillance after treatment. Only continued investigation with endoscopic diagnosis and treatment, as well as longitudinal follow-up, will determine methods of patients selection and the optimal use of topical chemotherapy.

Transurethral ultrasonic fragmentation of stones allows successful endoscopic removal of upper urinary calculi that otherwise would be considered too large to extract. We successfully extracted endoscopically 2 large renal pelvic and 5 large ureteral stones using transurethral ureteropyeloscopy and ultrasonic lithotripsy. The stone is visualized first with the ureteropyeloscope, and then engaged in a basket and either fragmented or disintegrated with the ultrasonic transducer. Any remaining small stone fragments can be retrieved with a stone basket or forceps. There has been little morbidity with this procedure and patients can return to normal activity after discharge from the hospital.

Flow cytometry was used to detect and quantify expression of a urothelial differentiation antigen (Om5) and nuclear DNA in exfoliated epithelial cells of the urinary bladder from 15 patients with nonpapillary carcinoma in situ during and after intravesical therapy with Bacillus Calmette-Guérin (BCG). Before BCG treatment exfoliated cells reacting with the mouse monoclonal antibody Om5 were found in 13 cases. Following treatment Om5 positive cells were still present in 9 cases but 4 patients who had had Om5 positive cells prior to BCG therapy no longer had detectable antigen-positive cells after therapy. Thus intravesical BCG therapy can alter detection of a urothelial differentiation antigen in exfoliated bladder epithelial cells. It is not certain whether this antigen or other differentiation antigens measured by flow cytometry will advance our present techniques for assessing effects of therapy on carcinoma in situ and other bladder tumors. However, five of nine patients showing persistence of Om5 positive cells after therapy were found to have recurrent tumor by biopsy and two others had positive cytology (median follow-up, 13 months). None of the four without detectable antigen-positive cells after therapy had clinical evidence of tumor by cystoscopy, biopsy, or cytology (median follow-up, 12 months). It now appears feasible and desirable to initiate clinical investigations of this and other differentiation antigens in combination with DNA by flow cytometry of bladder irrigation specimens.