Use of non-invasive uroflowmetry with simultaneous electromyography to monitor patient response to treatment for lower urinary tract conditions.

OBJECTIVE: Non-invasive uroflowmetry with simultaneous electromyography (uroflow/EMG) has previously been reported as effective in triaging patients into four specific non-neurogenic lower urinary tract (LUT) conditions for targeted treatment. In this study we sought to determine if the same parameters would be useful for measuring response to treatment. MATERIAL AND METHODS: We reviewed our database of normal children with LUT dysfunction, screened with uroflow/EMG, and diagnosed with a LUT condition: (1) dysfunctional voiding (DV); (2) idiopathic detrusor overactivity disorder (IDOD); (3) detrusor underutilization disorder (DUD); (4) primary bladder neck dysfunction (PBND). Pre- and on-treatment (minimum 3 months) uroflow/EMG parameters and subjective improvements were compared. RESULTS: Of 159 children (71 boys, 88 girls; median age 7.0 years, range 3.5-18.0 years), median follow up was 13.1 months (range 3-43 months). On targeted treatment, DV patients showed relaxation of pelvic floor during voiding and significant decrease in PVR on biofeedback; IDOD patients had normalization of short lag time and increased capacity on antimuscarinics; DUD patients had a decrease in capacity on timed voiding; PBND patients on alpha-blocker therapy showed improved uroflow rates and a decrease in mean EMG lag time (all p < 0.05). CONCLUSION: Non-invasive uroflow/EMG is useful not only for diagnosing specific LUT conditions, but also in objectively monitoring treatment efficacy. Subjective improvement on targeted therapy correlates well with objective improvements in uroflow/EMG parameters lending validation to this simplified approach to diagnosis.

A delicate subject: The impact of cultural factors on neonatal and perinatal decision making.

The neonatal intensive care unit (NICU) is a high-stress environment for both families and health care providers that can sometimes make appropriate medical decisions challenging. We present a review article of non-medical barriers to effective decision making in the NICU, including: miscommunication, mixed messages, denial, comparative social and cultural influences, and the possible influence of perceived legal issues and family reliance on information from the Internet. As examples of these barriers, we describe and discuss two cases that occurred simultaneously in the same NICU where decisions were influenced by social and cultural differences that were misunderstood by both medical staff and patients' families. The resulting stress and emotional discomfort created an environment with sub-optimal relationships between patients' families and health care providers. We provide background on the sources of conflict in these particular cases. We also offer suggestions for possible amelioration of similar conflicts with the twin goals of facilitating compassionate decision making in NICU settings and promoting enhanced well-being of both families and providers.

Measurement of the refractive index of highly turbid media: reply to comment.

Peiponen et al. [Opt. Lett.35, 4108 (2010)] have expressed concern that a theoretical model we proposed in Calhoun et al. [Opt. Lett.35, 1224 (2010)] for total internal reflection from a turbid medium may be inconsistent with the experimental data, in the sense that the model fails to take into account unexplained oscillations in our data. We show that their concern arises from misinterpretation of our data and theory, and is, therefore, unfounded. NOTE: Optics Letters apologizes to the authors for the delay in the publication of this Reply.

Measurement of the refractive index of highly turbid media.

We demonstrate a first simultaneous measurement of the real and imaginary parts of the refractive index of a highly turbid medium by observing the real-time reflectance profile of a divergent laser beam made incident on the surface of the turbid medium. We find that the reflectance data are well described by Fresnel theory that correctly includes the effect on total internal reflection of angle-dependent penetration into the turbid medium.

Diagnostic evaluation of children with daytime incontinence.

PURPOSE: This article is one of the standardization documents of the International Children's Continence Society, and discusses how anatomical/iatrogenic and functional/urodynamic causes of daytime incontinence in children of all ages are to be diagnosed, how neurogenic bladder dysfunction or urinary tract infection is excluded as a cause of the wetting, and how further diagnostic evaluation of children with disturbances such as overactive bladder, voiding postponement and dysfunctional voiding is performed. The roles of history taking (including prenatal and perinatal issues and family history), physical examination, diagnostic bladder diaries, noninvasive urodynamic investigations and radiological imaging are delineated but therapy is not within the scope of this document. MATERIALS AND METHODS: This document was designed and written by an international panel of authors with a large experience in assessment of children with incontinence. RESULTS: The best evidence was retrieved from the literature and assembled in a standardization document. CONCLUSIONS: Assessment of children with daytime symptoms is discussed. A noninvasive approach in these children allows us to select patients who will need a more invasive assessment.

Differential Vicia villosa agglutinin reactivity identifies three distinct dystroglycan complexes in skeletal muscle.

We present evidence for the expression of three alpha-dystroglycan glycoforms in skeletal muscle cells, including two minor glycoforms marked by either patent or latent reactivity with the N-acetylgalactosamine-specific lectin Vicia villosa agglutinin. Both minor glycoforms co-isolated with beta-dystroglycan, but not with other dystrophin/utrophin-glycoprotein complex components, suggesting that they may perform distinct or modified cellular functions. We also confirmed that both patent and latent V. villosa agglutinin-reactive alpha-dystroglycan glycoforms are expressed in C2C12 myotubes. However, we found that the combined effect of saturating concentrations of V. villosa agglutinin and laminin-1 were strictly additive with respect to acetylcholine receptor cluster formation in C2C12 myotubes, which suggests that laminin-1 and V. villosa agglutinin do not compete for the same binding site on the cell surface. Finally, although beta-N-acetylhexosaminidase digestion dramatically inhibited agrin-, V. villosa agglutinin-, and laminin-1-induced acetylcholine receptor clustering in C2C12 myotubes, treatment with this enzyme had no effect on the amount of alpha-dystroglycan that was bound to V. villosa agglutinin-agarose. We conclude that alpha-dystroglycan is not the V. villosa agglutinin receptor implicated in acetylcholine receptor cluster formation. However, our data provide new support for the hypothesis that different glycoforms of alpha-dystroglycan may perform distinct functions even within the same cell.

Selective inhibition of Src SH2 by a novel thiol-targeting tricarbonyl-modified inhibitor and mechanistic analysis by (1)H/(13)C NMR spectroscopy.

Detailed analysis of Src SH2 binding by peptides containing a novel tricarbonyl-modified pTyr moiety is described. We envisaged that Src SH2 selectivity might be obtained by exploiting the thiol group of Cys188 present in the pTyr binding pocket of the protein at the betaC3 position. Peptidyl as well as non-peptidyl compounds 1-4 possessing a 4-alpha,beta-diketoester-modified pTyr mimic exhibited micromolar affinity to Src SH2. Furthermore, these tricarbonyl compounds were selective for Src SH2 to the extent they showed no significant affinity for either Cys188Ser or Cys188Ala Src SH2 mutants. Upon closer examination of the binding of these tricarbonyls to Src SH2 using NMR of 13C-labeled compounds (6a, 6b, and 6c), we found that after the initial binding event the molecule disproportionated in a 'retro-Claisen' fashion to provide benzoic acid 16 and, following hydrolysis of the methyl ester 17, the hemiketal adduct of glyoxalic acid 18.

Screening guidelines for retinopathy of prematurity: the need for revision in extremely low birth weight infants.

OBJECTIVE: To determine whether significant retinopathy of prematurity (ROP) can be detected before 31 to 33 weeks' postmenstrual age (PMA) in extremely low birth weight (ELBW) infants. METHODS: Medical records of all ELBW infants (<1000 g at birth) admitted to our regional perinatal center between April 1995 and January 1999 were reviewed retrospectively. Screening examinations for ROP were routinely performed at 4 to 6 weeks' chronological age (CA) from birth and followed at least every other week. Data were collected for infants who developed ROP. We determined the PMA at which the first screening eye examination demonstrated prethreshold disease and the subsequent examination that showed threshold disease (if it occurred). The percentages of infants who developed prethreshold ROP diagnosed at

Mechanism of Inhibition of beta-site amyloid precursor protein-cleaving enzyme (BACE) by a statine-based peptide.

Inhibition of beta-site amyloid precursor protein-cleaving enzyme by a statine-based inhibitor has been studied using steady state and stopped-flow methods. A slow onset rate of inhibition has been observed under steady state conditions, and a K(i) of 22 nm has been derived using progress curves analysis. Simulation of stopped-flow protein fluorescence transients provided an estimate of the K(d) for initial inhibitor binding of 660 nm. A two-step inhibition mechanism is proposed, wherein slower "tightening up" of the initial encounter complex occurs. Two hypotheses have been proposed in the literature to address the nature of the slow step in the inhibition of aspartic proteases by peptidomimetic inhibitors: a conformational change related to the "flap" movement and displacement of a catalytic water. We compared substrate and inhibitor binding rates under pre-steady-state conditions. Both ligands are likely to cause flap movement, whereas no catalytic water replacement occurs during substrate binding. Our results suggest that both ligands bind to the enzyme at a rate significantly lower than the diffusion limit, but there are additional rate limitations involved in inhibitor binding, resulting in a k(on) of 3.5 x 10(4) m(-)1 s(-)1 for the inhibitor compared with 3.5 x 10(5) m(-)1 s(-)1 for the substrate. Even though specific intermediate formation steps might be different in the productive inhibitor and substrate binding to beta-site amyloid precursor protein-cleaving enzyme, a similar final optimized conformation is achieved in both cases, as judged by the comparable free energy changes (DeltaDeltaG of 2.01 versus 1.97 kcal/mol) going from the initial to the final enzyme-inhibitor or enzyme-substrate complexes.

Presenilin-1 and -2 are molecular targets for gamma-secretase inhibitors.

Presenilins are integral membrane protein involved in the production of amyloid beta-protein. Mutations of the presenilin-1 and -2 gene are associated with familial Alzheimer's disease and are thought to alter gamma-secretase cleavage of the beta-amyloid precursor protein, leading to increased production of longer and more amyloidogenic forms of A beta, the 4-kDa beta-peptide. Here, we show that radiolabeled gamma-secretase inhibitors bind to mammalian cell membranes, and a benzophenone analog specifically photocross-links three major membrane polypeptides. A positive correlation is observed among these compounds for inhibition of cellular A beta formation, inhibition of membrane binding and cross-linking. Immunological techniques establish N- and C-terminal fragments of presenilin-1 as specifically cross-linked polypeptides. Furthermore, binding of gamma-secretase inhibitors to embryonic membranes derived from presenilin-1 knockout embryos is reduced in a gene dose-dependent manner. In addition, C-terminal fragments of presenilin-2 are specifically cross-linked. Taken together, these results indicate that potent and selective gamma-secretase inhibitors block A beta formation by binding to presenilin-1 and -2.

Helicobacter pylori-selective antibacterials based on inhibition of pyrimidine biosynthesis.

We report the discovery of a class of pyrazole-based compounds that are potent inhibitors of the dihydroorotate dehydrogenase of Helicobacter pylori but that do not inhibit the cognate enzymes from Gram-positive bacteria or humans. In culture these compounds inhibit the growth of H. pylori selectively, showing no effect on other Gram-negative or Gram-positive bacteria or human cell lines. These compounds represent the first examples of H. pylori-specific antibacterial agents. Cellular activity within this structural class appears to be due to dihydroorotate dehydrogenase inhibition. Minor structural changes that abrogate in vitro inhibition of the enzyme likewise eliminate cellular activity. Furthermore, the minimum inhibitory concentrations of these compounds increase upon addition of orotate to the culture medium in a concentration-dependent manner, consistent with dihydroorotate dehydrogenase inhibition as the mechanism of cellular inhibition. The data presented here suggest that targeted inhibition of de novo pyrimidine biosynthesis may be a valuable mechanism for the development of antimicrobial agents selective for H. pylori.

Characterization of heat-inducible expression and cloning of HtpG (Hsp90 homologue) of Porphyromonas gingivalis.

Porphyromonas gingivalis is implicated in the etiology of periodontal disease. Associations between microbial virulence and stress protein expression have been identified in other infections. For example, Hsp90 homologues in several microbial species have been shown to contribute to virulence. We previously reported that P. gingivalis possessed an Hsp90 homologue (HtpG) which cross-reacts with human Hsp90. In addition, we found that elevated levels of serum antibody to Hsp90 stress protein in individuals colonized with this microorganism were associated with periodontal health. However, the role of HtpG in P. gingivalis has not been explored. Therefore, we cloned the htpG gene and investigated the characteristics of HtpG localization and expression in P. gingivalis. htpG exists as a single gene of 2,052 bp from which a single message encoding a mature protein of approximately 68 kDa is transcribed. Western blot analysis revealed that the 68-kDa polypeptide was stress inducible and that a major band at 44 kDa and a minor band at 40 kDa were present at constitutive levels. Cellular localization studies revealed that the 44- and 40-kDa species were associated with membrane and vesicle fractions, while the 68-kDa polypeptide was localized to the cytosolic fractions.

Cellular localization of a Hsp90 homologue in Porphyromonas gingivalis.

We previously reported an association between elevated serum antibody titers to the 90-kDa human heat shock protein (Hsp90), periodontal health and colonization by Porphyromonas gingivalis. In this study, we examined the cellular localization of the Hsp90 homologue of P. gingivalis. Cultures of P. gingivalis were heat-stressed (45 degrees C) and examined for localization of the Hsp90 homologue. Heat stress induced a 4-5-fold increase in anti-Hsp90 antibody reactivity over that of the unstressed controls. Western blot analysis revealed two bands (44 and 68 kDa) that reacted with anti-Hsp90 antibodies. The 68-kDa band was heat-inducible, while the 44-kDa band was not. Immunogold staining revealed that the Hsp90 homologue localized principally to the membrane and extracellular vesicles. Subcellular fractionation confirmed that the Hsp90 homologue was primarily membrane-associated.

Librarians' use of HealthWeb for reference and instruction.

HealthWeb is a selective Internet resource that links users to annotated, evaluated Internet resources in the health sciences. A collaborative effort of librarians from more than twenty academic institutions, it is a valuable tool for librarians at the Reference Desk and during instruction sessions. Contents of the Reference Resources section are highlighted, as well as an example of use of the Nursing page during a typical class.

Differential heparin sensitivity of alpha-dystroglycan binding to laminins expressed in normal and dy/dy mouse skeletal muscle.

The alpha-dystroglycan binding properties of laminins extracted from fully differentiated skeletal muscle were characterized. We observed that the laminins expressed predominantly in normal adult rat or mouse skeletal muscle bound alpha-dystroglycan in a Ca2+-dependent, ionic strength-sensitive, but heparin-insensitive manner as we had observed previously with purified placental merosin (Pall, E. A., Bolton, K. M., and Ervasti, J. M. 1996 J. Biol. Chem. 271, 3817-3821). Rat skeletal muscle laminins partially purified by heparin-agarose affinity chromatography also bound alpha-dystroglycan without sensitivity to heparin. We also confirm previous studies of dystrophic dy/dy mouse skeletal muscle showing that the alpha2 chain of merosin is reduced markedly and that the laminin alpha1 chain is not up-regulated detectably. However, we further observed a quantitative decrease in the expression of laminin beta/gamma chain immunoreactivity in alpha2 chain-deficient dy/dy skeletal muscle and reduced alpha-dystroglycan binding activity in laminin extracts from dy/dy muscle. Most interestingly, the alpha-dystroglycan binding activity of residual laminins expressed in merosin-deficient dy/dy skeletal muscle was inhibited dramatically (69 +/- 19%) by heparin. These results identify a potentially important biochemical difference between the laminins expressed in normal and dy/dy skeletal muscle which may provide a molecular basis for the inability of other laminin variants to compensate fully for the deficiency of merosin in some forms of muscular dystrophy.

Biofeedback therapy for children with dysfunctional voiding.

OBJECTIVES: Biofeedback therapy has been recognized as a treatment option for children with classic dysfunctional voiding (DV) where there is inadequate pelvic floor relaxation during voiding. However, there are few articles that discuss methodology and limited sites where it is available. In the hope of making biofeedback a more practical and accessible option, we report our indications, easy to duplicate methodology, and results. METHODS: Twenty-one consecutive children diagnosed with DV refractory to standard therapy were enrolled in our biofeedback program. Therapy consisted of extensive age-appropriate explanations of DV and demonstrations of normal and abnormal voiding patterns. Cyclic uroflow studies with pelvic floor electromyography are performed, which the child monitors on analog chart and audio recorders. The child returns weekly until consistent relaxation of the pelvic floor during voiding is demonstrated. Timing between sessions is then increased to monitor progress and retention of concepts previously taught. RESULTS: An excellent clinical response was one in which there was consistent relaxation of the pelvic floor throughout voiding, normal flow pattern, and no residual urine volume (urodynamic response), coupled with profound resolution of voiding symptoms. Seventeen of 21 (81%) had an excellent response, 3 (14%) had a fair response, and 1 (5%) was too inconsistent to rate. The average number of sessions to achieve a consistent urodynamic response was 3.7 (range 2 to 14) and full clinical response somewhat longer. Average follow-up since beginning therapy has been 34 months (range 14 to 51). CONCLUSIONS: Biofeedback therapy is an effective method for treating DV with poor pelvic floor relaxation. Although initially labor intensive, it yields sustained positive results in most patients in a short time.

Consciousness as a self-organizing process: an ecological perspective.

The evolution of consciousness is seen in the context of energy-driven evolution in general, where energy and information are understood as two sides of the same coin. From this perspective consciousness is viewed as an ecological system in which streams of cognitive, perceptual, and emotional information form a rich complex of interactions, analogous to the interactive metabolism of a living cell. The result is an organic, self-generating, or 'autopoietic', system, continuously in the act of creating itself. Evidence suggests that this process is chaotic, or at least chaotic-like, and capable of assuming a number of distinct states best understood as chaotic attractors.

Desmopressin for nocturnal incontinence in the spina bifida population.

PURPOSE: We report our experience with the use of desmopressin in the spina bifida population that is dry during the day but wet at night. MATERIALS AND METHODS: From 1994 to 1996, 18 patients with myelodysplasia were treated with desmopressin for persistent nocturnal enuresis. Initial dose was 40 mcg. before bedtime, decreased by intervals of 10 mcg. every 3 weeks. Patients were kept on the minimum dose required to keep them dry. We reviewed morning catheterized volumes, side effects and dosages needed to stay dry, and compared augmented patients with nonaugmented patients. RESULTS: Of 18 patients 14 (78%) reported marked improvement in nocturnal enuresis. Of 6 augmented patients 5 (83%) are dry compared to 9 of 12 nonaugmented patients (75%). There were no adverse side effects from the use of desmopressin. Average dose to stay dry was 20 mcg. for augmented and 30 mcg. for nonaugmented patients. Of the 4 patients who had persistent nocturnal incontinence despite desmopressin 3 (75%) became dry with a single catheterization in the middle of the night. CONCLUSIONS: Desmopressin is successful in treating nocturnal enuresis in the spina bifida patient with diurnal continence.