Antidiabetic drugs and kidney disease - Recommendations of the Swiss Society for Endocrinology and Diabetology.

Patients with diabetes are at risk of early renal function decline. Therefore, kidney function needs monitoring at least once per year. Once the glomerular filtration rate (GFR) is less than 60 ml/min, the pharmacokinetics of antidiabetic drugs may be altered. Sulfonylurea and glinide therapies are associated with a risk of hypoglycaemia which is increased in the presence of renal impairment. Most sulfonylureas must be discontinued once GFR is <60 ml/min. Some glinides may be continued beyond this threshold, in particular repaglinide, which may be used in dialysis patients. In the absence of comorbidities, metformin can be continued at lower doses until a GFR of 45 ml/min, but must be withdrawn in case of dehydration or during the administration of a nephrotoxic drug including dye for radiological investigations. Glitazones may worsen water and sodium retention in patients with renal impairment. The pharmacokinetics of all DPP-IV inhibitors except linagliptin are altered with impaired renal function. Only sitagliptin, saxagliptin and linagliptin may be used in advanced kidney disease, but experience is as yet very limited. GLP-1 agonists are contraindicated in moderate to advanced kidney disease.

Separation of free amino acids in human plasma by capillary electrophoresis with laser induced fluorescence: potential for emergency diagnosis of inborn errors of metabolism.

Free amino acids (AAs) in human plasma are derivatized with 3-(4-carboxybenzoyl)quinoline-2-carboxaldehyde (CBQCA) and analyzed by capillary electrophoresis (CE) with laser induced fluorescence (LIF) detection. The labeling procedure is significantly improved over results reported previously. Derivatization can be completed in 40 min, with concentrations as low as 4 x 10(-8) M successfully labeled in favourable cases. Twenty-nine AAs (including 2 internal standards) are identified and can be reproducibly separated in 70 min. Migration time RSD values for 23 of these AAs were calculated and found in the range from 0.5 to 4%. The rapid derivatization procedure and the resolution obtained in the separation are sufficient for a semi-quantitative, emergency diagnosis of several inborn errors of metabolism (IEM). Amino acid profiles for both normal donor plasma samples and plasma samples of patients suffering from phenylketonuria, tyrosinemia, maple syrup urinary disease, hyperornithinemia, and citrullinemia are studied.

Pharmacological screening of plants recommended by folk medicine as anti-snake venom: I. Analgesic and anti-inflammatory activities

We have observed that several plants used popularly as anti-snake venom show anti-inflammatory activity. From the list prepared by Rizzini, Mors and Pereira some species have been selected and tested for analgesic activity (number of contortions) and anti-inflammatory activity (Evans blue dye diffusion - 1% solution) according to Whittle's technique (intraperitoneal administration of 0.1 N-acetic acid 0.1 ml/10 g) in mice. Previous oral administration of a 10% infusion (dry plant) or 20% (fresh plant) corresponding to 1 or 2 g/Kg of Apuleia leiocarpa, Casearia sylvestris, Brunfelsia uniflora, Chiococca brachiata, Cynara scolymus, Dorstenia brasiliensis, Elephantopus scaber, Marsypianthes chamaedrys, Mikania glomerata and Trianosperma tayuya demonstrated analgesic and/or anti-inflammatory activities of varied intensity

Comparative study of human erythrocytes by digital holographic microscopy, confocal microscopy, and impedance volume analyzer.

Red blood cell (RBC) parameters such as morphology, volume, refractive index, and hemoglobin content are of great importance for diagnostic purposes. Existing approaches require complicated calibration procedures and robust cell perturbation. As a result, reference values for normal RBC differ depending on the method used. We present a way for measuring parameters of intact individual RBCs by using digital holographic microscopy (DHM), a new interferometric and label-free technique with nanometric axial sensitivity. The results are compared with values achieved by conventional techniques for RBC of the same donor and previously published figures. A DHM equipped with a laser diode (lambda = 663 nm) was used to record holograms in an off-axis geometry. Measurements of both RBC refractive indices and volumes were achieved via monitoring the quantitative phase map of RBC by means of a sequential perfusion of two isotonic solutions with different refractive indices obtained by the use of Nycodenz (decoupling procedure). Volume of RBCs labeled by membrane dye Dil was analyzed by confocal microscopy. The mean cell volume (MCV), red blood cell distribution width (RDW), and mean cell hemoglobin concentration (MCHC) were also measured with an impedance volume analyzer. DHM yielded RBC refractive index n = 1.418 +/- 0.012, volume 83 +/- 14 fl, MCH = 29.9 pg, and MCHC 362 +/- 40 g/l. Erythrocyte MCV, MCH, and MCHC achieved by an impedance volume analyzer were 82 fl, 28.6 pg, and 349 g/l, respectively. Confocal microscopy yielded 91 +/- 17 fl for RBC volume. In conclusion, DHM in combination with a decoupling procedure allows measuring noninvasively volume, refractive index, and hemoglobin content of single-living RBCs with a high accuracy.

Muntatge i caracterització d'una placa DSSC: Buscant potència

Treball de recerca realitzat per alumnes d'ensenyament secundari i guardonat amb un Premi CIRIT per fomentar l'esperit científic del Jovent l'any 2009. Els objectius inicials foren la construcció d una 'Cèl•lula Solar Sensibilitzada mitjançant un Colorant’ (DSSC) amb el tint d una col llombarda i posterior caracterització segons el dossier 'Nanocrystalline Solar Cell Kit: Recreating Photosynthesis’. Les DSSC (Dye Sensitized Solar Cell) són un tipus de cèl•lules que imiten els principis que la fotosíntesis ha fet servir exitosament durant més de 3,5 bilions d anys. S’han construït algunes DSSC i se n’ha provat la seva eficiència. El seu funcionament es basa en l’energia d’un fotó que excita un electró i el fa saltar de nivell energètic fins que es desprèn de l’àtom de colorant, deixant un forat en la molècula. Aquest electró lliure passa a través de la capa de TiO2 fins arribar a la càrrega on es genera el corrent elèctric. Tot seguit, l’electró arriba al contra-elèctrode i és aquí on entra en contacte amb l’electròlit, el mediador iode/triiode. Aquest regenera l’electró, que anteriorment ha saltat del colorant, oxidant-se ell mateix.

A rapid, reliable method of evaluating growth and viability of intraerythrocytic protozoan hemoparasites using fluorescence flow cytometry

Fluorescence flow cytometry was employed to assess the potential of a vital dye, hydroethiedine, for use in the detection and monitoring of the viability of hemoparasites in infected erythrocytes, using Babesia bovis as a model parasite. The studies demonstrated that hydroethidine is taken up by B. bovis and metabolically converted to the DNA binding fluorochrone, ethidium. Following uptake of the dye, erythrocytes contamine viable parasites were readily distinguished and quantitated. Timed studies with the parasiticidal drug, Ganaseg, showed that it is possible to use the fluorochrome assay to monitor the effects of the drug on the rate of replication and viability of B. bovis in culture. The assay provides a rapid method for evaluation of the in vitro effect of drugs on hemoparasites and for analysis of the effect of various components of the immune response, such as lymphokines, monocyte products, antibodies, and effector cells (T, NK, LAK, ADCC) on the growth and viability of intraerythrocytic parasites.

Sentinel lymph node involvement and a high Breslow index are independent factors of risk for early relapse of melanoma.

AIM: The clinical relevance of sentinel lymph node (SLN) analysis was evaluated prospectively and compared with other known risk factors of relapse in early stage melanoma. METHODS: Surgery was guided by lymphoscintigraphy, blue dye and gamma probe detection. SLN were analysed by haematoxylin eosin (HE) histochemistry and multimarker immunohistochemistry (IHC). Disease free survival (DFS) was evaluated with Kaplan-Meier plots according to different parameters and Cox analyses of variance. RESULTS: From 210 patients a total of 381 SLN were excised. Lymphoscintigraphy identified all excised SLN with only 2 false positive lymphatic lakes. Fifty patients (24%) had tumour positive SLN. With a mean follow-up of 31.3 months, 29 tumour recurrences were observed, 19 (38%) in 50 SLN positive and 10 (6%) in 160 SLN negative patients. Strong predictive factors for early relapse (p < 0.0005) were SLN positivity and a high Breslow index. CONCLUSION: SLN tumour positivity is an independent factor of high risk for early relapse with a higher power of discrimination than the Breslow index.

Variable phenotypic expressivity in a Swiss family with autosomal dominant retinitis pigmentosa due to mutation T494m in the Prpf3 gene

Purpose:to describe the clinical features in a five generations family segregating autosomal dominant retinitis pigmentosa and to identify the causative gene Patient and Methods:Twenty five individuals of a large five-generation family originating from Western Switzerland were ascertained for phenotypic and genotypic characterization. Ophthalmologic evaluations included color vision testing, Goldman perimetry and digital fundus photography. Some patients had autofluorescence (AF) imaging, ocular coherence tomography (OCT) and ISCEV-standard full-field electroretinography (ERG). Blood samples were collected from 10 affected (4 to 70 years of age) and 15 unaffected members after informed consent. DNA was isolated and exons and intron-exons junctions of known adRP genes were sequenced using a Big Dye sequencing kit 1.1. Results:Age of onset of nightblindness and severity of progression of the disease was variable between members of the family. Some patients had early onset of nightblindess aged 3, others at mid-twenties. Most patients had visual acuity above 0.6 for the first 4 decades. Two older patients still had good vision (0.4) in their seventies. Myopia (range: -2 to -5) was noticed in most affected subjects. Fundus findings showed areas of atrophy along the arcades. The AF imaging showed a large high density ring bilaterally. A T494M change was found in exon 11 of PRPF3 gene. The change segregates with the disease in the family. Conclusion: A mutation in the PRPF3 gene is rare compared with other genes causing ADRP. Although a T494M change has been reported, our family is the first one with a variable expressivity. Mutations in PRPF3 gene can cause a variable phenotype of ADRP unlike the previously described Danish and English families. Our report gives a better understanding as to the phenotype/genotype description of ADRP due to PRPF3 mutation.

Accuracy of sentinel lymph node dissection for melanoma staging in the presence of a collision tumour with a lymphoproliferative disease.

Sentinel lymph node dissection (SLND) identifies melanoma patients with metastatic disease who would benefit from radical lymph node dissection (RLND). Rarely, patients with melanoma have an underlying lymphoproliferative disease, and melanoma metastases might develop as collision tumours in the sentinel lymph node (SLN). The aim of this study was to measure the incidence and examine the effect of collision tumours on the accuracy of SLND and on the validity of staging in this setting. Between 1998 and 2012, 750 consecutive SLNDs were performed in melanoma patients using the triple technique (lymphoscintigraphy, gamma probe and blue dye). The validity of SLND in collision tumours was analysed. False negativity was reflected by the disease-free survival. The literature was reviewed on collision tumours in melanoma. Collision tumours of melanoma and chronic lymphocytic leukaemia (CLL) were found in two SLN and in one RLND (0.4%). Subsequent RLNDs of SLND-positive cases were negative for melanoma. The patient with negative SLND developed relapse after 28 months with an inguinal lymph node metastasis of melanoma; RLND showed collision tumours. The literature review identified 12 cases of collision tumours. CLL was associated with increased melanoma incidence and reduced overall survival. This is, to our knowledge, the first assessment of the clinical value of SLND when collision tumours of melanoma and CLL are found. In this small series of three patients with both malignancies present in the same lymph node basin, lymphocytic infiltration of the CLL did not alter radioisotope uptake into the SLN. No false-negative result was observed. Our data suggest the validity of SLND in collision tumours, but given the rarity of the problem, further studies are necessary to confirm this reliability.

Cross-talk between glutamate and potassium regulation at the astrocyte membrane

Astrocytes play a central role in the brain by regulating glutamate and extracellular potassium concentrations ([K+]0), both released by neurons into the extracellular space during neuronal activity. Glutamate uptake is driven by the inwardly directed sodium gradient across the astrocyte membrane and involves the influx of three sodium ions and one proton and the efflux of one K+ ion per glutamate molecule. The glutamate transport induced rise in intracellular sodium stimulates the Na+/K+-ATPase which leads to significant energetic costs in astrocytes. To evaluate how these two fundamental functions of astrocytes, namely glutamate transport and K+ buffering, which are directly associated with neuronal activity, coexist and if they influence each other, in this thesis work we examined different cellular parameters of astrocytes. We therefore investigated the impact of altered [K+]0 on glutamate transporter activity. To assess this question we measured intracellular sodium fluctuations in mouse primary cultured astrocytes using dynamic fluorescence imaging. We found that glutamate uptake was tightly modulated both in amplitude and kinetics by [K+]0. Elevated [K+]0 strongly decreased glutamate transporter activity, with significant consequences on the cells energy metabolism. To ultimately evaluate potential effects of [K+]0 and glutamate on the astrocyte mitochondrial energy production we extended these studies by investigating their impact on the cytosolic and mitochondrial pH. We found that both [K+],, and glutamate strongly influenced cytosolic and mitochondrial pH, but in opposite directions. The effect of a simultaneous application of K+ and glutamate, however, did not fit with the arithmetical sum of each individual effects, suggesting that an additional non¬linear process is involved. We also investigated the impact of [K+]0 and glutamate transport, respectively, on intracellular potassium concentrations ([K+]0 in cultured astrocytes by characterizing and applying a newly developed Insensitive fluorescent dye. We observed that [K+]i followed [K+]0 changes in a nearly proportional way and that glutamate superfusion caused a reversible, glutamate-concentration dependent drop of [K+],, Our study shows the powerful influence of [K+]u on glutamate capture. These findings have strong implications for our understanding of the tightly regulated interplay between astrocytes and neurons in situations where [K+]0 undergoes large activity-dependent fluctuations. However, depending on the extent of K+ versus glutamate extracellular rise, energy metabolism in astrocytes will be differently regulated. Moreover, the novel insights obtained during this thesis work help understanding some of the underlying processes that prevail in certain pathologies of central nervous system, such as epilepsy and stroke. These results will possibly provide a basis for the development of novel therapeutic strategies. -- Les astrocytes jouent un rôle central dans le cerveau en régulant les concentrations de potassium (K+) et de glutamate, qui sont relâchés par les neurones dans l'espace extracellulaire lorsque ceux- ci sont actifs. La capture par les astrocytes du glutamate est un processus secondairement actif qui implique l'influx d'ions sodium (Na+) et d'un proton, ainsi que l'efflux d'ions K+, ce processus entraîne un coût métabolique important. Nous avons évalué comment ces fonctions fondamentales des astrocytes, la régulation du glutamate et du K+ extracellulaire, qui sont directement associés à l'activité neuronale, coexistent et si elles interagissent, en examinant différents paramètres cellulaires. Dans ce projet de thèse nous avons évalué l'impact des modifications de la concentration de potassium extracellulaire ([K+],,) sur le transport du glutamate. Nous avons mesuré le transport du glutamate par le biais des fluctuations internes de Na+ grâce à un colorant fluorescent en utilisant de l'imagerie à fluorescence dynamique sur des cultures primaires d'astrocytes. Nous avons trouvé que la capture du glutamate était étroitement régulée par [K+]0 aussi bien dans son amplitude que dans sa cinétique. Par la suite, nous avons porté notre attention sur l'impact de [K+]0 et du glutamate sur le pH cytosolique et mitochondrial de l'astrocyte dans le but, in fine, d'évaluer les effets potentiels sur la production d'énergie par la mitochondrie. Nous avons trouvé qu'autant le K+ que le glutamate, de manière individuelle, influençaient fortement le pH, cependant dans des directions opposées. Leurs effets individuels, ne peuvent toutefois pas être additionnés ce qui suggère qu'un processus additionnel non-linéaire est impliqué. En appliquant une nouvelle approche pour suivre et quantifier la concentration intracellulaire de potassium ([K+]0 par imagerie à fluorescence, nous avons observé que [K+]i suivait les changements de [K+]0 de manière quasiment proportionnelle et que la superfusion de glutamate induisait un décroissement rapide et réversible de [K+]i, qui dépend de la concentration de glutamate. Notre étude démontre l'influence de [K+]0 sur la capture du glutamate. Ces résultats permettent d'améliorer notre compréhension de l'interaction entre astrocytes et neurones dans des situations où [K+]0 fluctue en fonction de l'activité neuronale. Cependant, en fonction de l'importance de l'augmentation extracellulaire du K+ versus le glutamate, le métabolisme énergétique des astrocytes va être régulé de manière différente. De plus, les informations nouvelles que nous avons obtenues durant ce travail de thèse nous aident à comprendre quelques- uns des processus sous-jacents qui prévalent dans certaines pathologies du système nerveux central, comme par exemple l'épilepsie ou l'accident vasculaire cérébral. Ces informations pourront être importantes à intégrer dans la cadre du développement de nouvelles stratégies thérapeutiques.

Noninvasive imaging of 5-HT3 receptor trafficking in live cells: from biosynthesis to endocytosis.

Sequential stages in the life cycle of the ionotropic 5-HT(3) receptor (5-HT(3)R) were resolved temporally and spatially in live cells by multicolor fluorescence confocal microscopy. The insertion of the enhanced cyan fluorescent protein into the large intracellular loop delivered a fluorescent 5-HT(3)R fully functional in terms of ligand binding specificity and channel activity, which allowed for the first time a complete real-time visualization and documentation of intracellular biogenesis, membrane targeting, and ligand-mediated internalization of a receptor belonging to the ligand-gated ion channel superfamily. Fluorescence signals of newly expressed receptors were detectable in the endoplasmic reticulum about 3 h after transfection onset. At this stage receptor subunits assembled to form active ligand binding sites as demonstrated in situ by binding of a fluorescent 5-HT(3)R-specific antagonist. After novel protein synthesis was chemically blocked, the 5-HT(3) R populations in the endoplasmic reticulum and Golgi cisternae moved virtually quantitatively to the cell surface, indicating efficient receptor folding and assembly. Intracellular 5-HT(3) receptors were trafficking in vesicle-like structures along microtubules to the cell surface at a velocity generally below 1 mum/s and were inserted into the plasma membrane in a characteristic cluster distribution overlapping with actin-rich domains. Internalization of cell surface 5-HT(3) receptors was observed within minutes after exposure to an extracellular agonist. Our orchestrated use of spectrally distinguishable fluorescent labels for the receptor, its cognate ligand, and specific organelle markers can be regarded as a general approach allowing subcellular insights into dynamic processes of membrane receptor trafficking.

Activation of the heat shock response in plants by chlorophenols: transgenic Physcomitrella patens as a sensitive biosensor for organic pollutants.

The ability to detect early molecular responses to various chemicals is central to the understanding of biological impact of pollutants in a context of varying environmental cues. To monitor stress responses in a model plant, we used transgenic moss Physcomitrella patens expressing the beta-glucuronidase reporter (GUS) under the control of the stress-inducible promoter hsp17.3B. Following exposure to pollutants from the dye and paper industry, GUS activity was measured by monitoring a fluorescent product. Chlorophenols, heavy metals and sulphonated anthraquinones were found to specifically activate the hsp17.3B promoter (within hours) in correlation with long-term toxicity effects (within days). At mildly elevated physiological temperatures, the chemical activation of this promoter was strongly amplified, which considerably increased the sensitivity of the bioassay. Together with the activation of hsp17.3B promoter, chlorophenols induced endogenous chaperones that transiently protected a recombinant thermolabile luciferase (LUC) from severe heat denaturation. This sensitive bioassay provides an early warning molecular sensor to industrial pollutants under varying environments, in anticipation to long-term toxic effects in plants. Because of the strong cross-talk between abiotic and chemical stresses that we find, this P. patens line is more likely to serve as a direct toxicity bioassay for pollutants combined with environmental cues, than as an indicator of absolute toxicity thresholds for various pollutants. It is also a powerful tool to study the role of heat shock proteins (HSPs) in plants exposed to combined chemical and environmental stresses.

Photodynamic induced uptake of liposomal doxorubicin to rat lung tumors parallels tumor vascular density.

BACKGROUND: Visudyne®-mediated photodynamic therapy (PDT) at low drug/light conditions has shown to selectively enhance the uptake of liposomal doxorubicin in subpleural localized sarcoma tumors grown on rodent lungs without causing morphological alterations of the lung. The present experiments explore the impact of low-dose PDT on liposomal doxorubicin (Liporubicin™) uptake to different tumor types grown on rodent lungs. MATERIAL AND METHODS: Three groups of Fischer rats underwent subpleural generation of sarcoma, mesothelioma, or adenocarcinoma tumors on the left lung. At least five animals of each group (sarcoma, n = 5; mesothelioma, n = 7; adenocarcinoma, n = 5) underwent intraoperative low-dose (10 J/cm(2) at 35 mW/cm(2) ) PDT with 0.0625 mg/kg Visudyne® of the tumor and the lower lobe. This was followed by intravenous (IV) administration of 400 µg Liporubicin™. After a circulation time of 60 min, the tumor-bearing lung was processed for HPLC analyses. At least five animals per group underwent the same procedure but without PDT (sarcoma, n = 5; mesothelioma, n = 5; adenocarcinoma, n = 6). Five untreated animals per group underwent CD31 immunostaining of their tumors with histomorphometrical assessment of the tumor vascularization. RESULTS: Low-dose PDT significantly enhanced Liporubicin™ uptake to all tumor types (sarcoma, P = 0.0007; mesothelioma, P = 0.001; adenocarcinoma, P = 0.02) but not to normal lung tissue compared to IV drug administration alone. PDT led to a significantly increased ratio of tumor to lung tissue drug uptake for all three tumor types (P < 0.05). However, the tumor drug uptake varied between tumor types and paralleled tumor vascular density. The vascular density was significantly higher in sarcoma than in adenocarcinoma (P < 0.001) and mesothelioma (P < 0.001), whereas there was no significant difference between adenocarcinoma and mesothelioma. CONCLUSION: Low-dose Visudyne®-mediated PDT selectively enhances the uptake of systemically administered liposomal doxorubicin in tumors without affecting the drug uptake to normal lung. However, drug uptake varied significantly between tumor types and paralleled tumor vascular density.

Dermatologie esthétique et correctrice: applications cliniques et rôle social [Esthetic and corrective dermatology: clinical applications and social role].

Skin diseases may have severe aesthetic and psychological repercussions leading sometimes to discriminations and social isolation. Dermatologists have contributed to the development of many cosmetic procedures: peelings, botulinum toxin or hyaluronic acid injections, lasers, blepharoplasty, facelift, etc. Many of these treatments have interesting clinical applications and may help numerous patients with skin diseases to return to a normal social life.

Comparison of the efficacy and longevity of nonpenetrating glaucoma surgery with and without a new, nonabsorbable hydrophilic implant.

BACKGROUND AND OBJECTIVE: To compare the efficacy and longevity of nonpenetrating glaucoma surgery with and without the use of a nonabsorbable hydrophilic implant at the Oxford Eye Centre, Johannesburg, South Africa, and the Glaucoma Unit, Jules Gonin Ophthalmic Hospital, Lausanne, Switzerland. PATIENTS AND METHODS: In a nonrandomized, prospective study between March 1997 and December 2001, 48 eyes of 32 patients aged 18 to 86 years with primary open-angle glaucoma underwent nonpenetrating glaucoma surgery; 25 eyes with the implant and 23 eyes without it. Intraocular pressure (IOP) was recorded preoperatively and postoperatively at 1, 7, and 14 days, at 1, 3, and 6 months, and thereafter every 6 months. RESULTS: The mean preoperative IOP was 27.5 +/- 11.8 mm Hg (range, 20 to 64 mm Hg) in the implant group and 24.8 +/- 7.1 mm Hg (range, 16 to 38 mm Hg) in the control group. During the first 18 months of follow-up, both groups showed identical IOP progression and the mean IOP remained less than 14 mm Hg. After 2 years of follow-up, the IOP started to rise in the control group but remained stable in the implant group. After 30 months, the mean IOP was 12.4 +/- 2 mm Hg and the IOP decrease in percentage was 62% +/- 6% in the implant group (n = 13) versus 16.1 +/- 3 mm Hg and 34% +/- 13% in the control group (n = 15) (mean IOP, P = .0022; mean IOP decrease in percentage, P = .01). CONCLUSIONS: During the first 18 months, there was no difference in the outcomes between the two groups. After 2 years of follow-up, the mean IOP was lower and the IOP decrease in percentage was greater in the implant group compared with the control group.