Increased neuronal nitric oxide synthase dimerisation is involved in rat and human pancreatic beta cell hyperactivity in obesity.

AIMS/HYPOTHESIS: Pancreatic beta cell hyperactivity is known to occur in obesity, particularly in insulin-resistant states. Our aim was to investigate whether changes in neuronal nitric oxide synthase (nNOS) function affect beta cell compensation in two relevant models: the Zucker fa/fa rats and pancreatic islets from obese humans. METHODS: Glucose-induced insulin response was evaluated in the isolated perfused rat pancreas and in human pancreatic islets from obese individuals. Expression of nNOS (also known as NOS1) and subcellular localisation of nNOS were studied by quantitative RT-PCR, immunoblotting, immunofluorescence and electron microscopy. RESULTS: Pancreatic beta cells from Zucker fa/fa rats and obese individuals were found to be hyper-responsive to glucose. Pharmacological blockade of nNOS was unable to modify beta cell response to glucose in fa/fa rats and in islets from obese individuals, suggesting an abnormal control of insulin secretion by the enzyme. In both cases, nNOS activity in islet cell extracts remained unchanged, despite a drastic increase in nNOS protein and an enhancement in the dimer/monomer ratio, pointing to the presence of high amounts of catalytically inactive enzyme. This relative decrease in activity could be mainly related to increases in islet asymmetric dimethyl-arginine content, an endogenous inhibitor of nNOS activity. In addition, mitochondrial nNOS level was decreased, which contrasts with a strongly increased association with insulin granules. CONCLUSIONS/INTERPRETATION: Increased nNOS production and dimerisation, together with a relative decrease in catalytic activity and relocalisation, are involved in beta cell hyperactivity in insulin-resistant rats but also in human islets isolated from obese individuals.

Human recombinant anti-thyroperoxidase autoantibodies: in vitro cytotoxic activity on papillary thyroid cancer expressing TPO.

BACKGROUND: Thyroid cancers are difficult to treat due to their limited responsiveness to chemo- and radiotherapy. There is thus a great interest in and a need for alternative therapeutic approaches. RESULTS: We studied the cytotoxic activity of anti-thyroperoxidase autoantibodies (anti-TPO aAbs, expressed in baculovirus/insect cell (B4) and CHO cells (B4') or purified from patients' sera) against a papillary thyroid cancer (NPA) cell line. Anti-TPO aAbs from patients' sera led to a partial destruction of NPA cell line by complement-dependent cytotoxicity (CDC) and antibody-dependent cell-mediated cytotoxicity (ADCC) and exhibited an anti-proliferative activity. Comparison of the cytotoxic activity of anti-TPO aAbs shows that B4' induced an anti-proliferative effect and a better ADCC than B4, but a lower one than anti-TPO aAbs from patients' sera. Antibody-dependent cell-mediated cytotoxicity was increased when human peripheral blood mononuclear cells were used as effector cells, suggesting that FcgammaRs, CD64, CD32 and CD16 are involved. Indeed, anti-TPO aAbs from patients' sera, but not B4 and B4', exhibited CDC activity. CONCLUSIONS: These data indicate that anti-TPO aAbs display moderate ADCC and anti-proliferative activities on NPA cells; IgG glycosylation appears to be important for cytotoxic activity and ADCC efficiency depends on FcgammaR-bearing cells. Finally, recombinant human anti-TPO aAbs cannot yet be considered as an optimal tool for the development of a novel therapeutic approach for thyroid cancer.

Salivary IgA response of triathletes participating in the French Iron Tour.

Athletes are susceptible to upper respiratory tract infections (URTI) during intense training and after major competitions. Secretory IgA, which is the predominant antibody of the mucosal immune system, is the major effector of host-resistance to many microorganisms causing URTI. Previous studies have shown that salivary IgA-mediated immunity decreases after a single short distance triathlon, but the effect of repeated triathlon competitions on secretory IgA levels remains unknown. The purpose of this study was to examine the salivary IgA response of elite triathletes in repeated triathlon races during the 2001 French Iron Tour (FIT). Eight triathletes participated in this study. Saliva samples were collected daily after waking up (fasting basal state), before (pre-race) and after (post-race) each day's competition. Salivary IgA, total protein, and flow rate were measured. Salivary IgA concentrations were measured by an enzyme-linked immunosorbent assay. The salivary flow rate was significantly decreased after each race compared with the fasting basal state (p < 0.01). The salivary IgA concentration of the fasting basal state decreased over the FIT and was even lower than that of the post-race values (p < 0.05). The salivary IgA secretion rate of the fasting basal state decreased by 51.9% over the FIT (p < 0.05). Our data suggest that intense exercise repeated daily has a cumulative negative effect on basal levels of salivary IgA.

Estudio jurisprudencial de la responsabilidad legal del personal sanitario en la reformulación de medicamentos / common law study of the legal responsability of health care staff related to drug reformulation

Objetivo: Analizar la responsabilidad del personal sanitario alelaborar reformulaciones (modificación de la dosis, forma farmacéuticao vía de administración de especialidades farmacéuticas)desde la jurisprudencia del Tribunal Supremo y la AudienciaNacional.Método: Búsqueda y análisis de jurisprudencia y estudios jurídicosen las bases de datos “El Derecho”, “Difusión Jurídica” e“Indret”.Resultados: El personal sanitario tiene una obligación demedios –no de resultados– aplicando unas normas de cuidadoque constituyen la “Lex Artis”, y que pueden ir más allá de lasmeras normas jurídicas. La falta a estas normas de cuidado, ladenegación de auxilio o la falta de respeto a la autonomía delpaciente pueden ser comportamientos negligentes. Se encontraron4 casos en la jurisprudencia. En los dos casos en que secumplieron las normas de cuidado, incluyendo la reformulación,los profesionales sanitarios fueron absueltos, mientras queen otros dos casos en que no se aplicaron reformulaciones,cuando las “Lex Artis” así lo imponía, los profesionales fueroncondenados.Conclusiones: La reformulación de especialidades farmacéuticas,incluidas en la Lex Artis, es una práctica aceptada por elTribunal Supremo y la Audiencia Nacional, siendo causa de condenael no recurrir a las mismas cuando los conocimientos científicosdel momento así lo aconsejen

Objective: To analyze the responsibility of health care staff indrug reformulation (change of dose, pharmaceutical form or routeof administration of medicinal products) based on the commonlaw of the High Court and the National Court.Method: Search and analysis of common law and legal studiesincluded in databases “El Derecho”, “Difusión Jurídica” and“Indret”.Results: Health care staff has means –not outcomes– obligationsaccording to the care standards included in the “Lex Artis”that can go beyond the mere legal standards. Failure to apply thiscare standards, denial of assistance or disrespect to the autonomyof the patient can be negligent behaviors. We found 4 cases incommon law. In the two cases in which care standards were compliedwith, including reformulation, health care professionals wereacquitted, whereas in the other two cases in which reformulationswere not used even though the “Lex Artis” required them, theprofessionals were condemned.Conclusions: Reformulation of medicinal products, as setforth in the Lex Artis, is a practice accepted by the High Courtand the National Court and failure to use it when the scientificknowledge advises so is a cause for conviction

[Common law study of the legal responsibility of health care staff related to drug reformulation]. / Estudio jurisprudencial de la responsabilidad legal del personal sanitario en la reformulación de medicamentos.

OBJECTIVE: To analyze the responsibility of health care staff in drug reformulation (change of dose, pharmaceutical form or route of administration of medicinal products) based on the common law of the High Court and the National Court. METHOD: Search and analysis of common law and legal studies included in databases "El Derecho", "Difusión Jurídica" and "Indret". RESULTS: Health care staff has means--not outcomes--obligations according to the care standards included in the "Lex Artis" that can go beyond the mere legal standards. Failure to apply these care standards, denial of assistance or disrespect to the autonomy of the patient can be negligent behavior. We found 4 cases in common law. In the two cases in which care standards were complied with, including reformulation, health care professionals were acquitted, whereas in the other two cases in which reformulations were not used even though the "Lex Artis" required them, the professionals were condemned. CONCLUSIONS: Reformulation of medicinal products, as set forth in the Lex Artis, is a practice accepted by the High Court and the National Court and failure to use it when the scientific knowledge advises so is a cause for conviction.

Kinetics of appearance of intestinal lesions in mice mono-associated with a lethal or non-lethal strain of Clostridium difficile.

The kinetics of the appearance of intestinal lesions induced by orogastric inoculation of gnotobiotic mice with a lethal strain of Clostridium difficile (VPI) that produced toxins A and B in vivo and in vitro was studied and compared with the lesions induced by non-lethal C. difficile strain 786 that produced toxins A and B in vitro but only toxin B in measurable amounts in vivo. Different portions of the intestine were removed 12, 20, 26 and 30 h after inoculation and studied by scanning electronmicroscopy. The remaining portions were homogenised for enumeration of C. difficile and quantification of toxin A by enzyme immunoassay and toxin B by cytotoxicity. The results showed that, following inoculation: (i) measurable amounts of both toxins were necessary to produce lesions; (ii) with strain VPI, the caecum and the colon were rapidly impaired and completely destroyed after 1 day, whereas the small intestine was damaged to a lesser extent; (iii) C. difficile strain 786 did not cause mucosal damage but induced mucus-like or serum-like secretion and morphological changes in the caecal enterocytes only.

Factors involved in catheter obstruction during long-term peritoneal insulin infusion.

OBJECTIVE: To analyze the efficacy of ECPII and the factors responsible for technical problems often encountered. This treatment has been in use with IDDM patients since 1980. RESEARCH DESIGN AND METHODS: Forty-four IDDM patients were treated by ECPII for 42-78 mo (mean, 53 mo). RESULTS: Glycemic equilibrium was improved during treatment (mean plasma glucose level, 7.6 mM; mean GHb level, 8%). Catheter blockage was the main reason for ECPII failure (74%). Mean catheter survival of each catheter, determined by actuarial analysis, was 11.7 mo and significantly decreased with subsequent implantation. SEM of the catheter tips showed deposits composed of fibrin and cells occluding the inner lumen. Factors such as age, sex, local infection, and low insulin basal rate were not found to have any incidence on the catheter survival. Placement of the catheter in the upper part of the peritoneum, however, increased catheter survival. Anti-insulin antibodies did not seem to be directly involved in blockage. CONCLUSIONS: We conclude from this long-term experience that during ECPII, catheter blockage remains the major recurring complication, probably involving a local immune-inflammatory response in the peritoneum.

Effect of oral Saccharomyces boulardii treatment on the activity of Clostridium difficile toxins in mouse digestive tract.

Human antibiotic-associated diarrhoea and pseudomembranous colitis are partly due to toxin production by Clostridium difficile. It is now well documented that Saccharomyces boulardii protects against C. difficile induced diseases. In an attempt to understand better the mechanism of this protective effect, the action of S. boulardii on a crude toxin preparation was studied in vitro and in vivo. The results showed that the yeast had no effect on the toxins in vitro but was able to protect mice inoculated with these toxins. Furthermore, the observation by scanning electron microscopy that the mucosa of S. boulardii protected mice was not damaged suggest that the yeast mainly acts on the intestinal mucosa.

Prevention of Clostridium difficile-induced experimental pseudomembranous colitis by Saccharomyces boulardii: a scanning electron microscopic and microbiological study.

The ability of Saccharomyces boulardii to protect mice against intestinal pathology caused by toxinogenic Clostridium difficile was studied. Different regions of the intestine of experimental mice were prepared for observation by scanning electron microscopy or homogenized for C. difficile enumeration and quantification of toxin A by enzyme immunoassay and toxin B by cytotoxicity. The test group was treated for 6 d with an S. boulardii suspension in drinking water and challenged with C. difficule on day 4. The three control groups were: axenic mice, mice treated with only S. boulardii and mice only challenged with C. difficile. The results showed that: (i) 70% of the mice infected by C. difficile survived when treated with S. boulardii; (ii) the C. difficile-induced lesions on the small and large intestinal mucosa were absent or markedly less severe in S. boulardii-treated mice; and (iii) there was no decrease in the number of C. difficile but rather a reduction in the amount of toxins A and B in S. boulardii-treated mice.

El sindrome de Kearns y Sayre. / Kearns-Sayre syndrome

Se presentan 2 pacientes portadores de oftalmoplegia externa cronica progresiva, retinopatia pigmentaria atipica y bloqueo cardiaco, lo cual se describe como sindrome de Kearns y Sayre. Las oftalmoplegias asociadas a otras anomalias generales degenerativas se conocen como oftalmoplegia plus. Constituyen numerosos sindromes no siempre claramente individualizados por la sobre-posicion de sus sintomas o signos.Su origen miogenico o neurogenico no se ha aclarado, histologicamente se describen alteraciones de las mitocondrias y sus enzimas en las miofibrillas, tejidos oculares, etc. La herencia del sindrome de Kearns y Sayre seria autosomica recesiva o dominante, de expresion fenotipica muy variable, lo que obligaria al examen a los familiares incluso presuntamente sanos