Bladder augmentation with small intestinal submucosa leads to unsatisfactory long-term results

PURPOSE

To evaluate the use of small intestinal submucosa (SIS) for bladder augmentation in a series of select patients.

MATERIAL AND METHODS

Six patients (age 6.5-15.4, mean 9.8 years) underwent bladder augmentation with SIS: one after a cloacal exstrophy repair, one after multiple surgery of the bladder because of vesicoureteral reflux, two with spina bifida, two after bladder exstrophy repair. All suffered from a microbladder with a mean volume of 61.5 ml (range 15-120, 7-36% of expected bladder capacity for age). Preoperative bladder compliance ranged from 1.0 to 3.3 (mean 1.3) ml/cmH2O.

RESULTS

Follow-up time ranged from 4.6 to 33.5 (mean 24.4) months. An increase of bladder volume was achieved in four patients (53-370 ml, 16-95% of expected bladder capacity for age). Bladder compliance postoperatively ranged from 0.9 to 5.6 (mean 3.0) ml/cmH2O. Histological examinations showed a complete conversion of SIS, leaving irregular urothelial lining and bladder wall containing muscular, vascular and relatively thick connective tissue in four patients and regular urothelium in two patients. Major complications were bladder stones in two patients and a bladder rupture in one patient.

CONCLUSION

Bladder augmentation with SIS in humans failed to fulfill the hopes raised by animal studies. Due to the insufficient increase in bladder compliance and therefore failure to accomplish sufficient protection of the upper urinary tract, bladder augmentation with SIS cannot be recommended as a substitute for enterocystoplasty.

Positive allosteric modulation by ivermectin of human but not murine P2X7 receptors

BACKGROUND AND PURPOSE

In mammalian cells, the anti-parasitic drug ivermectin is known as a positive allosteric modulator of the ATP-activated ion channel P2X4 and is used to discriminate between P2X4- and P2X7-mediated cellular responses. In this paper we provide evidence that the reported isoform selectivity of ivermectin is a species-specific phenomenon.

EXPERIMENTAL APPROACH

Complementary electrophysiological and fluorometric methods were applied to evaluate the effect of ivermectin on recombinantly expressed and on native P2X7 receptors. A biophysical characterization of ionic currents and of the pore dilation properties is provided.

KEY RESULTS

Unexpectedly, ivermectin potentiated currents in human monocyte-derived macrophages that endogenously express hP2X7 receptors. Likewise, currents and [Ca(2+) ](i) influx through recombinant human (hP2X7) receptors were potently enhanced by ivermectin at submaximal or saturating ATP concentrations. Since intracellular ivermectin did not mimic or prevent its activity when applied to the bath solution, the binding site of ivermectin on hP2X7 receptors appears to be accessible from the extracellular side. In contrast to currents through P2X4 receptors, ivermectin did not cause a delay in hP2X7 current decay upon ATP removal. Interestingly, NMDG(+) permeability and Yo-Pro-1 uptake were not affected by ivermectin. On rat or mouse P2X7 receptors, ivermectin was only poorly effective, suggesting a species-specific mode of action.

CONCLUSIONS AND IMPLICATIONS

The data indicate a previously unrecognized species-specific modulation of human P2X7 receptors by ivermectin that should be considered when using this cell-biological tool in human cells and tissues.

Accessory subunits alter the temperature sensitivity of Kv4.3 channel complexes

In human atrial myocytes the transient outward current I(to) develops a conspicuous faster inactivation with increasing temperatures. Since β-subunits are known to modulate I(to) current kinetics, we hypothesized that the temperature sensitivity of I(to) is not only determined by the property of the ion-passing α-subunit Kv4.3 but also by its interaction with accessory β-subunits. We therefore studied the influence of the transmembrane β-subunits KCNE1, KCNE2 and DPP6 on Kv4.3/KChIP2 channels in CHO cells at room temperature and at physiological temperature. Exposure to 37°C caused a significant acceleration of the channel kinetics, whereas current densities and voltage dependences remained unaltered at 37°C compared to 23°C. However, Kv4.3/KChIP2 channels without transmembrane β-subunits showed the strongest temperature sensitivity with considerably increased rates of activation and inactivation at 37°C. KCNE2 significantly slowed the current kinetics at 37°C compared to Kv4.3/KChIP2 channels, whereas KCNE1 did not influence the channel properties at both temperatures. Interestingly, the accelerating effects of DPP6 on current kinetics described at 23°C were diminished at physiological temperature, thus at 37°C current kinetics became remarkably similar for channel complexes Kv4.3/KChIP2 with and without DPP6 isoforms. A Markov state model was developed on the basis of experimental measurements to simulate the influence of β-subunits on Kv4.3 channel complex at both temperatures. In conclusion, the remarkably fast kinetics of the native I(to) at 37°C could be reproduced by co-expressing Kv4.3, KChIP2, KCNE2 and DPP6 in CHO cells, whereas the high temperature sensitivity of human I(to) could be not mimicked.

Influence of helix 12 of Ultraspiracle on Drosophila melanogaster ecdysone receptor function

Although it has no ligand, helix 12 in the ligand binding domain of Ultraspiracle (USP) is locked in an antagonistic position. To investigate whether this position is of functional importance, we enhanced the flexibility of helix 12 by mutating two amino acids (259, located in L1-3 and F491 in helix 12). Mutated USP reduces the stability of USP and all isoforms of the ecdysone receptor (EcR) and impairs nuclear localization and DNA binding of EcR/USP(L259A/F491/A), resulting in lower levels of basal transcriptional activity. Although the affinity of the ligand ponasterone A to EcR/USP(L259/F491) is moderately diminished, hormone-induced stimulation of transcriptional activity is normal. Potentiation of the ecdysone response by juvenile hormone (JH) is selectively increased in mutated heterodimers with EcR-B1, demonstrating that the antagonistic position impairs functional interaction of the EcR complex with JHIII.

[Epithelial neoplasia of the appendix: what has recently changed?]

Appendicular tumors are mostly found incidentally in up to 1.5% of all appendectomies. Neuroendocrine tumors are the commonest malignancies, and are associated with an excellent long-term prognosis. While small lesions located at the appendicular tip can be treated with simple appendectomy, advanced tumors require right hemicolectomy. Goblet cell carcinoids are rare tumors showing a mixed phenotype. Long-term outcome is impaired, and for most cases a right hemicolectomy is mandatory. Colonic-type adenocarcinomas have a similar behavior like conventional colonic cancer and should be treated similarly. Mucinous neoplasias possess the characteristic of extensive mucin production with intraperitoneal spread. Treatment options are ranging from right hemicolectomy to multivisceral resection with intraperitoneal chemotherapy.

[Preoperative nutrition in abdominal surgery: recommendations and reality]

Malnutrition concerns up to 50% at in-hospital admission. Its diagnosis and treatment are fundamental parts of the surgical approach because nutritional status directly influences the clinical outcome. The Nutritional Risk Score (NRS-2002) represents the recommended screening tool by the European Society of Parenteral and Enteral Nutrition (ESPEN). Patients with a score > or = 3 and aged > 70 years old, should receive a nutritional support during 7-14 day before surgery. Depending on patient's clinical conditions, the enteral route of administration should be preferred. Despite strong evidence in favor of nutritional supplementation, much effort must be done to implement these supportive strategies in the everyday clinical practice.

[Time required and associated costs for implementation of home medication review with associated pharmaceutical and medical evaluation in the ambulatory health care sector]

INTRODUCTION

We aimed to estimate the time which is needed to conduct a home medication review (HMR) in the context of the AGnES implementation studies (AGnES=GP-supporting, community-based, e-health-assisted, systemic intervention). In a subsequent step associated costs were calculated.

METHODS

IT-supported HMR were conducted by specially qualified AGnES-practice assistants to detect selected drug-related problems (DRP). The patient received pharmaceutical care by their local pharmacist and medical evaluation by their GP, respectively.

RESULTS

The data from 471 patients (w: 339; m: 132) were evaluated (median age: w=81; m=78). The interview to detect selected DRP was 6 min (median) long. The subsequent drug record took 14.4 min. There was an additional effort for documentation of 5 min. The local pharmacist needed a median time of 15 min for pharmaceutical evaluation, whereas the GP needed 8 min. The estimated costs accounted for: AGnES-practice assistant: 9.12 €; pharmacist: 11.05 €; GP: 6.30 €. The overall estimated costs were 26.47 €.

CONCLUSION

For the first time we present objective costs which were associated with the implementation of HMR. Due to high DRP-induced costs the HMR should be mandatory for groups with a high risk like for the occurrence of DRP.

Interaction of the N-terminus of ecdysone receptor isoforms with the ligand-binding domain

Ecdysone receptor (EcR) isoforms exert different biological functions, although they vary only in their N-terminal domain. Despite identical C-termini, which mediate hormone-induced activity, the influence of ligand is isoform specific, which indicates an N/C-interaction. The position of helix 12 with and without hormone varies among isoforms and modifies N/C-interaction determined by fluorescence resonance-energy transfer (FRET), which depends on the salt bridge between helices 4 and 12 of the ligand-binding domain (LBD). Disruption of the salt bridge by mutation of K497 (helix 4) had no effect on basal N/C-interaction, but prevented the hormone-induced increase, which was partially restored by a salt bridge with reversed polarity. The heterodimerization partner Ultraspiracle (Usp) can compensate for the disruption of the salt bridge. Without ligand the AB-domains of EcR-A and EcR-B1, but not EcR-B2, interact with the LBD via K497 and repress transcriptional activity. This intramolecular cross talk between N- and C-terminus along with the position of helix 12 stabilized by K497 regulates transcriptional activity of EcR isoforms.

Factors influencing long-term changes in mental health after interferon-alpha treatment of chronic hepatitis C

BACKGROUND

Antiviral treatment with interferon-alpha (IFN-alpha) is associated with several acute psychiatric side effects. Little is known about long-term effects on mental health after treatment independent from viral response and the influence of pre-existing psychiatric risk-factors.

AIM

To evaluate long-term effects of antiviral treatment with interferon-alpha (IFN-alpha) on mental health in patients with psychiatric risk factors.

METHOD

We prospectively investigated long-term mental health changes in 81 hepatitis C virus-infected patients. Psychiatric outcome was measured with the Montgomery-Asberg Depression Scale (MADRS), Brief Psychiatric Rating Scale, the Global Social Functioning Scale and the Global Clinical Impression Scale 6 months after the end of antiviral treatment with IFN-alpha and ribavirin.

RESULTS

Six months after antiviral therapy, 49% of the patients showed a worsening and 27.2% an improvement of depression scores. The most important predictor for a long-term improvement of depression scores was a pre-treatment MADRS score > or =5 (OR 14.21, 95% CI: 2.51-81.30). Patients with pre-existing psychiatric disorders (OR = 0.117, 95% CI: 0.024-0.558), methadone substitution (OR = 0.20, 95% CI: 0.045-0.887) or genotype 2/3 (OR = 0.341, 95% CI: 0.138-0.845) were significantly less likely to show a long-term worsening of depressive symptoms.

CONCLUSIONS

Pre-existing psychiatric risk factors increase the chance for a long-term improvement and reduce the risk for a long-term worsening of mental health after antiviral treatment of chronic hepatitis C with IFN-alpha.

CHARMM: the biomolecular simulation program

CHARMM (Chemistry at HARvard Molecular Mechanics) is a highly versatile and widely used molecular simulation program. It has been developed over the last three decades with a primary focus on molecules of biological interest, including proteins, peptides, lipids, nucleic acids, carbohydrates, and small molecule ligands, as they occur in solution, crystals, and membrane environments. For the study of such systems, the program provides a large suite of computational tools that include numerous conformational and path sampling methods, free energy estimators, molecular minimization, dynamics, and analysis techniques, and model-building capabilities. The CHARMM program is applicable to problems involving a much broader class of many-particle systems. Calculations with CHARMM can be performed using a number of different energy functions and models, from mixed quantum mechanical-molecular mechanical force fields, to all-atom classical potential energy functions with explicit solvent and various boundary conditions, to implicit solvent and membrane models. The program has been ported to numerous platforms in both serial and parallel architectures. This article provides an overview of the program as it exists today with an emphasis on developments since the publication of the original CHARMM article in 1983.

Predictors of HIV testing and serostatus amongst children admitted to Port Moresby General Hospital

The aim of this study was to identify factors associated with current HIV (human immunodeficiency virus) testing practice at Port Moresby General Hospital and positive serostatus among children tested, as a basis for contributing to guidelines on HIV testing for children in Papua New Guinea. Data were extracted from hospital records to determine the demographic and presenting clinical characteristics of admitted children tested for HIV serostatus between 1 December 2005 and 30 November 2006. These data were compared with corresponding data from untested control children from the same wards. The same characteristics were compared between seropositive and seronegative cases. Odds ratios were derived for potential predictors of testing and its outcome. During the study period, HIV tests were reported on 215 children, of whom 57 were seropositive. Controls were 264 untested children. Tested children were more likely to be aged 18 months or less, to have been admitted for more than 7 days, and to have diarrhoea, be malnourished or have oral candidiasis. Among children tested, suspected tuberculosis as a presenting illness was significantly predictive of HIV-positive serostatus. This study indicates that certain clinical factors associated with HIV-positive status in children may not yet have been incorporated into testing practice, and underlines the importance of developing a systematic approach to testing children for HIV in Papua New Guinea.

Chemical synthesis, pharmacological characterization, and possible formation in unicellular fungi of 3-hydroxy-anandamide

The fungal pathogen Candida albicans transforms arachidonic acid (AA) into 3-hydroxyarachidonic acid [3R-HETE], and we investigated if its nonpathogenic and 3R-HETE-producing close relative, Dipodascopsis uninucleata, could similarly transform the endocannabinoid/endovanilloid anandamide into 3-hydroxyanandamide (3-HAEA). We found that D. uninucleata converts anandamide into 3-HAEA, and we therefore developed an enantiodivergent synthesis for this compound to study its pharmacological activity. Both enantiomers of 3-HAEA were as active as anandamide at elevating intracellular Ca2+ via TRPV1 receptors overexpressed in HEK-293 cells, while a approximately 70-90-fold and approximately 45-60-fold lower affinity at cannabinoid CB1 and CB2 receptors was instead observed. Patch clamp recordings showed that 3R-HAEA activates a TRPV1-like current in TRPV1-expressing HEK-293 cells. Thus, 3R-HETE-producing yeasts might convert anandamide released by host cells at the site of infection into 3R-HAEA, and this event might contribute to the inflammatory and algogenous responses associated to fungal diseases.

The toxicity testing of double-walled nanotubes-contaminated food to Eisenia veneta earthworms

Nanotechnology is playing an increasing role in the society, but very little is known about the environmental toxicity of nanotechnological products. Few previous studies have been published with regard to the effect of nanoparticles on soil organisms. The present paper deals with the toxicity of carbon double-walled nanotubes (DWNT) and C60 fullerenes to the soil-dwelling earthworm Eisenia veneta, with the aim of evaluating the lethal and sub-lethal toxicity. Reproduction of E. veneta was affected by DWNT administered through food at concentrations above 37 mg DWNT/kg food. The most sensitive toxicological parameter was reproduction (cocoon production), with no effect on hatchability, survival or mortality at up to 495 mg DWNT/kg and 1000 mg C60/kg.