Effect of SR 49059, a V1a vasopressin receptor antagonist, in Raynaud's phenomenon.

OBJECTIVE: To assess whether vasopressin V1a receptor blockade reduces the abnormal vasoactive response to cold in patients suffering from Raynaud's phenomenon (RP). METHODS: SR 49059, an orally active, non-peptidic vasopressin V1a receptor antagonist, was given orally (300 mg once daily) to 20 patients with RP in a single-centre, double-blind, placebo-controlled, randomized cross-over study with two 7-day periods of treatment separated by 21 days of washout. Bilateral finger systolic blood pressure and skin temperature were assessed before and after immersion of the hand in cold water for 3 min (15 degrees C) during the screening phase and three times (before and 2 and 4 h after drug intake) on days 1 and 7 of each of the two treatment periods. Recovery of digital pressure and skin temperature was measured 0, 10, 20 and 32 min after the end of the cold immersion test. RESULTS: SR 49059 significantly attenuated the cold-induced fall in systolic pressure by 14.5% (95% confidence interval 0-29; P = 0.045) on the most affected hand on day 7 compared with placebo. Temperature recovery after the end of the cold test showed a trend to enhancement 2 and 4 h after SR 49059 on day 7 (P = 0.060 and P = 0.062 respectively). The beneficial effects on finger pressure and temperature recovery were obtained without changes in supine blood pressure or in heart rate. CONCLUSION: SR 49059 given orally once a day for 7 days to patients with RP showed favourable effects compared with placebo on finger systolic pressure and temperature recovery after cold immersion, without inducing side-effects.

The CD8 beta polypeptide is required for the recognition of an altered peptide ligand as an agonist.

T cell activation is triggered by the specific recognition of cognate peptides presented by MHC molecules. Altered peptide ligands are analogs of cognate peptides which have a high affinity for MHC molecules. Some of them induce complete T cell responses, i.e. they act as agonists, whereas others behave as partial agonists or even as antagonists. Here, we analyzed both early (intracellular Ca2+ mobilization), and late (interleukin-2 production) signal transduction events induced by a cognate peptide or a corresponding altered peptide ligand using T cell hybridomas expressing or not the CD8 alpha and beta chains. With a video imaging system, we showed that the intracellular Ca2+ response to an altered peptide ligand induces the appearance of a characteristic sustained intracellular Ca2+ concentration gradient which can be detected shortly after T cell interaction with antigen-presenting cells. We also provide evidence that the same altered peptide ligand can be seen either as an agonist or a partial agonist, depending on the presence of CD8beta in the CD8 co-receptor dimers expressed at the T cell surface.

Targeting vascular NADPH oxidase 1 blocks tumor angiogenesis through a PPARα mediated mechanism.

Reactive oxygen species, ROS, are regulators of endothelial cell migration, proliferation and survival, events critically involved in angiogenesis. Different isoforms of ROS-generating NOX enzymes are expressed in the vasculature and provide distinct signaling cues through differential localization and activation. We show that mice deficient in NOX1, but not NOX2 or NOX4, have impaired angiogenesis. NOX1 expression and activity is increased in primary mouse and human endothelial cells upon angiogenic stimulation. NOX1 silencing decreases endothelial cell migration and tube-like structure formation, through the inhibition of PPARα, a regulator of NF-κB. Administration of a novel NOX-specific inhibitor reduced angiogenesis and tumor growth in vivo in a PPARα dependent manner. In conclusion, vascular NOX1 is a critical mediator of angiogenesis and an attractive target for anti-angiogenic therapies.

TLR3 and Rig-like receptor on myeloid dendritic cells and Rig-like receptor on human NK cells are both mandatory for production of IFN-gamma in response to double-stranded RNA.

Cross-talk between NK cells and dendritic cells (DCs) is critical for the potent therapeutic response to dsRNA, but the receptors involved remained controversial. We show in this paper that two dsRNAs, polyadenylic-polyuridylic acid and polyinosinic-polycytidylic acid [poly(I:C)], similarly engaged human TLR3, whereas only poly(I:C) triggered human RIG-I and MDA5. Both dsRNA enhanced NK cell activation within PBMCs but only poly(I:C) induced IFN-gamma. Although myeloid DCs (mDCs) were required for NK cell activation, induction of cytolytic potential and IFN-gamma production did not require contact with mDCs but was dependent on type I IFN and IL-12, respectively. Poly(I:C) but not polyadenylic-polyuridylic acid synergized with mDC-derived IL-12 for IFN-gamma production by acting directly on NK cells. Finally, the requirement of both TLR3 and Rig-like receptor (RLR) on mDCs and RLRs but not TLR3 on NK cells for IFN-gamma production was demonstrated using TLR3- and Cardif-deficient mice and human RIG-I-specific activator. Thus, we report the requirement of cotriggering TLR3 and RLR on mDCs and RLRs on NK cells for a pathogen product to induce potent innate cell activation.

What impact do systemically administrated bisphosphonates have on oral implant therapy? A systematic review.

OBJECTIVES: The aim of this systematic review is to evaluate, analysing the dental literature, whether: * Patients on intravenous (IV) or oral bisphosphonates (BPs) can receive oral implant therapy and what could be the risk of developing bisphosphonate-related osteonecrosis of the jaw (BRONJ)? * Osseointegrated implants could be affected by BP therapy. MATERIAL AND METHODS: A Medline search was conducted and all publications fulfilling the inclusion and exclusion criteria from 1966 until December 2008 were included in the review. Moreover, the Cochrane Data Base of Systematic Reviews, and the Cochrane Central Register of Controlled Trials and EMBASE (from 1980 to December 2008) were searched for English-language articles published between 1966 and 2008. Literature search was completed by a hand research accessing the references cited in all identified publications. RESULTS: The literature search rendered only one prospective and three retrospective studies. The prospective controlled non-randomized clinical study followed patients with and without BP medication up to 36 months after implant therapy. The patients in the experimental group had been on oral BPs before implant therapy for periods ranging between 1 and 4 years. None of the patients developed BRONJ and implant outcome was not affected by the BP medication. The three selected retrospective studies (two case-controls and one case series) yielded very similar results. All have followed patients on oral BPs after implant therapy, with follow-up ranging between 2 and 4 years. BRONJ was never reported and implant survival rates ranged between 95% and 100%. The literature search on BRONJ including guidelines and recommendations found 59 papers, from which six were retrieved. Among the guidelines, there is a consensus on contraindicating implants in cancer patients under IV-BPs and not contraindicating dental implants in patients under oral-BPs for osteoporosis. CONCLUSIONS: From the analysis of the one prospective and the three retrospective series (217 patients), the placement of an implant may be considered a safe procedure in patients taking oral BPs for <5 years with regard to the occurrence of BRONJ since in these studies no BRONJ has been reported. Moreover, the intake of oral-BPs did not influence short-term (1-4 years) implant survival rates.

Failure of voriconazole to cure disseminated zygomycosis in an immunocompromised child.

Voriconazole is increasingly used as a first-line agent for empirical antifungal therapy of prolonged febrile neutropenia in paediatric cancer patients. We describe the case of a 9-year-old patient with stage IV Burkitt lymphoma, who developed pulmonary and splenic zygomycosis while receiving voriconazole for persistent febrile neutropenia. The causative agent, Absidia corymbifera, was identified by broad-range fungal PCR in a lung biopsy sample. The patient was successfully treated with a combination of partial resection of the left upper lobe and antifungal therapy with high-dose liposomal amphotericin B followed by oral itraconazole as demonstrated by resolving pulmonary infiltrates on serial high resolution CT scans. CONCLUSION: This case emphasises that the lack of in vitro activity of voriconazole against zygomycetes is clinically relevant. Failure of voriconazole in suspected fungal infection should be investigated for the possibility of zygomycosis. Broad-range polymerase chain reaction may be able to identify the causative organism when cultures remain sterile.

Heavy metal ions are potent inhibitors of protein folding.

Environmental and occupational exposure to heavy metals such as cadmium, mercury and lead results in severe health hazards including prenatal and developmental defects. The deleterious effects of heavy metal ions have hitherto been attributed to their interactions with specific, particularly susceptible native proteins. Here, we report an as yet undescribed mode of heavy metal toxicity. Cd2+, Hg2+ and Pb2+ proved to inhibit very efficiently the spontaneous refolding of chemically denatured proteins by forming high-affinity multidentate complexes with thiol and other functional groups (IC(50) in the nanomolar range). With similar efficacy, the heavy metal ions inhibited the chaperone-assisted refolding of chemically denatured and heat-denatured proteins. Thus, the toxic effects of heavy metal ions may result as well from their interaction with the more readily accessible functional groups of proteins in nascent and other non-native form. The toxic scope of heavy metals seems to be substantially larger than assumed so far.

Activation of electrical triggers of atrial fibrillation in hyperthyroidism.

CONTEXT: A shortening of the atrial refractory period has been considered as the main mechanism for the increased risk of atrial fibrillation in hyperthyroidism. However, other important factors may be involved. OBJECTIVE: Our objective was to determine the activity of abnormal supraventricular electrical depolarizations in response to elevated thyroid hormones in patients without structural heart disease. PATIENTS AND DESIGN: Twenty-eight patients (25 females, three males, mean age 43+/-11 yr) with newly diagnosed and untreated hyperthyroidism were enrolled in a prospective trial after exclusion of heart disease. Patients were followed up for 16 +/- 6 months and studied at baseline and 6 months after normalization of serum TSH levels. MAIN OUTCOME MEASURES: The incidence of abnormal premature supraventricular depolarizations (SVPD) and the number of episodes of supraventricular tachycardia was defined as primary outcome measurements before the start of the study. In addition, heart rate oscillations (turbulence) after premature depolarizations and heart rate variability were compared at baseline and follow-up. RESULTS: SVPDs decreased from 59 +/- 29 to 21 +/- 8 per 24 h (P = 0.003), very early SVPDs (so called P on T) decreased from 36 +/- 24 to 3 +/- 1 per 24 h (P < 0.0001), respectively, and nonsustained supraventricular tachycardias decreased from 22 +/- 11 to 0.5 +/- 0.2 per 24 h (P = 0.01) after normalization of serum thyrotropin levels. The hyperthyroid phase was characterized by an increased heart rate (93 +/- 14 vs. 79 +/- 8 beats/min, P < 0.0001) and a decreased turbulence slope (3.6 vs. 9.2, P = 0.003), consistent with decreased vagal tone. This was confirmed by a significant decrease of heart rate variability. CONCLUSION: Hyperthyroidism is associated with an increased supraventricular ectopic activity in patients with normal hearts. The activation of these arrhythmogenic foci by elevated thyroid hormones may be an important causal link between hyperthyroidism and atrial fibrillation.

Renal function in patients with HIV starting therapy with tenofovir and either efavirenz, lopinavir or atazanavir.

BACKGROUND: Tenofovir is associated with reduced renal function, but it is not clear whether there is a greater decline in renal function when tenofovir is co-administered with a boosted protease inhibitor rather than with a nonnucleoside reverse transcriptase inhibitor (NNRTI). METHODS: We calculated the estimated glomerular filtration rate (eGFR) for patients in the Swiss HIV Cohort Study. We estimated the difference in eGFR over time between first therapies containing tenofovir and either the NNRTI efavirenz or the protease inhibitors lopinavir (LPV/r) or atazanavir (ATV/r), both boosted with ritonavir. RESULTS: Patients on a first therapy of tenofovir co-administered with efavirenz (n  = 484), LPV/r (n = 269) and ATV/r (n =  187) were followed for a median of 1.7, 1.2 and 1.3 years, respectively. Relative to tenofovir and efavirenz, the estimated difference in eGFR for tenofovir and LPV/r was -2.6 ml/min per 1.73 m [95% confidence interval (CI) -7.3 to 2.2) during the first 6 months of therapy, then followed by a difference of 0.0 ml/min per 1.73 m (95% CI -1.1 to 1.1) for each additional 6 months of therapy. Relative to tenofovir and efavirenz, the estimated difference in eGFR for tenofovir and ATV/r was -7.6 ml/min per 1.73 m (95% CI -11.8 to -3.4) during the first 6 months of therapy, then followed by a difference of -0.5 ml/min per 1.73 m (95% CI -1.6 to 0.7) for each additional 6 months of therapy. CONCLUSION: Tenofovir with either boosted protease inhibitor leads to a greater initial decline in eGFR than tenofovir with efavirenz; this decline may be worse with ATV/r than with LPV/r.

Effect of an 8-weeks aerobic training program in elderly on oxidative stress and HSP72 expression in leukocytes during antioxidant supplementation.

OBJECTIVE: To investigate the effect of aerobic training in the context of antioxidant supplementation on systemic oxidative stress and leukocytes heat shock protein (Hsp)72 expression in the elderly. DESIGN: Sixteen septuagenarians (8 males and 8 females, mean age 74.6) were supplemented with Vitamin C and E (respectively 500 and 100mg per day) and randomly assigned either to sedentary (AS) or individualized aerobically trained (AT) group for 8 weeks. METHODS: Plasma Vitamin C and E concentrations and aerobic fitness, as well as resting and post graded exercise (GXT) Hsp72 expression in leukocytes, plasma levels of thiobarbituric acid reactive substances (TBARS) and advanced oxidation protein product (AOPP) were measured pre and post training / supplementation. RESULTS: At the end of the intervention, the two groups showed a significant increase in resting plasma vitamin C and E (approximately 50 and 20% increase respectively) and a significant decrease in both resting and post GXT plasma TBARS and AOPP (approximately 25 and 20% decrease respectively). These changes were of similar magnitude in the two groups. The reduced oxidative stress was concomitant with a 15% decreased expression of Hsp72 in monocytes and granulocytes in both groups. CONCLUSION: This study provides evidence that in elderly, increased concentration of antioxidant vitamins C and E is associated with a reduction in oxidative stress and leukocytes Hsp72. In this context, 8 weeks of aerobic training has no impact on oxidative stress or leukocytes Hsp72 expression in elderly people.

In vivo reprogramming of circuit connectivity in postmitotic neocortical neurons.

The molecular mechanisms that control how progenitors generate distinct subtypes of neurons, and how undifferentiated neurons acquire their specific identity during corticogenesis, are increasingly understood. However, whether postmitotic neurons can change their identity at late stages of differentiation remains unknown. To study this question, we developed an electrochemical in vivo gene delivery method to rapidly manipulate gene expression specifically in postmitotic neurons. Using this approach, we found that the molecular identity, morphology, physiology and functional input-output connectivity of layer 4 mouse spiny neurons could be specifically reprogrammed during the first postnatal week by ectopic expression of the layer 5B output neuron-specific transcription factor Fezf2. These findings reveal a high degree of plasticity in the identity of postmitotic neocortical neurons and provide a proof of principle for postnatal re-engineering of specific neural microcircuits in vivo.

Tobacco and cannabis smoking cessation can lead to intoxication with clozapine or olanzapine

Plasma levels of clozapine and olanzapine are lower in smokers than in nonsmokers, which is mainly due to induction of cytochrome P4501A2 (CYP1A2) by some smoke constituents. Smoking cessation in patients treated with antipsychotic drugs that are CYP1A2 substrates may result in increased plasma levels of the drug and, consequently, in adverse drug effects. Two cases of patients who smoked tobacco and cannabis are reported. The first patient, who was receiving clozapine treatment, developed confusion after tobacco and cannabis smoking cessation, which was related to increased clozapine plasma levels. The second patient, who was receiving olanzapine treatment, showed important extrapyramidal motor symptoms after reducing his tobacco consumption. The clinical implication of these observations is that smoking patients treated with CYP1A2 substrate antipsychotics should regularly be monitored with regard to their smoking consumption in order to adjust doses in cases of a reduction or increase in smoking.

In pancreatic carcinoma, dual EGFR/HER2 targeting with cetuximab/trastuzumab is more effective than treatment with trastuzumab/erlotinib or lapatinib alone: implication of receptors' down-regulation and dimers' disruption.

We previously demonstrated the synergistic therapeutic effect of the cetuximab (anti-epidermal growth factor receptor [EGFR] monoclonal antibody, mAb)-trastuzumab (anti-HER2 mAb) combination (2mAbs therapy) in HER2(low) human pancreatic carcinoma xenografts. Here, we compared the 2mAbs therapy, the erlotinib (EGFR tyrosine kinase inhibitor [TKI])-trastuzumab combination and lapatinib alone (dual HER2/EGFR TKI) and explored their possible mechanisms of action. The effects on tumor growth and animal survival of the three therapies were assessed in nude mice xenografted with the human pancreatic carcinoma cell lines Capan-1 and BxPC-3. After therapy, EGFR and HER2 expression and AKT phosphorylation in tumor cells were analyzed by Western blot analysis. EGFR/HER2 heterodimerization was quantified in BxPC-3 cells by time-resolved FRET. In K-ras-mutated Capan-1 xenografts, the 2mAbs therapy gave significantly higher inhibition of tumor growth than the erlotinib/trastuzumab combination, whereas in BxPC-3 (wild-type K-ras) xenografts, the erlotinib/trastuzumab combination showed similar growth inhibition but fewer tumor-free mice. Lapatinib showed no antitumor effect in both types of xenografts. The efficacy of the 2mAbs therapy was partly Fc-independent because F(ab')(2) fragments of the two mAbs significantly inhibited BxPC-3 growth, although with a time-limited therapeutic effect. The 2mAbs therapy was associated with a reduction of EGFR and HER2 expression and AKT phosphorylation. BxPC-3 cells preincubated with the two mAbs showed 50% less EGFR/HER2 heterodimers than controls. In pancreatic carcinoma xenografts, the 2mAbs therapy is more effective than treatments involving dual EGFR/HER2 TKIs. The mechanism of action may involve decreased AKT phosphorylation and/or disruption of EGFR/HER2 heterodimerization.

Dexamethasone intravitreal implant for noninfectious intermediate or posterior uveitis.

OBJECTIVE: To evaluate the safety and efficacy of 2 doses of dexamethasone intravitreal implant (DEX implant) for treatment of noninfectious intermediate or posterior uveitis. METHODS: In this 26-week trial, eyes with noninfectious intermediate or posterior uveitis were randomized to a single treatment with a 0.7-mg DEX implant (n = 77), 0.35-mg DEX implant (n = 76), or sham procedure (n = 76). MAIN OUTCOME MEASURE: The main outcome measure was the proportion of eyes with a vitreous haze score of 0 at week 8. RESULTS: The proportion of eyes with a vitreous haze score of 0 at week 8 was 47% with the 0.7-mg DEX implant, 36% with the 0.35-mg DEX implant, and 12% with the sham (P < .001); this benefit persisted through week 26. A gain of 15 or more letters from baseline best-corrected visual acuity was seen in significantly more eyes in the DEX implant groups than the sham group at all study visits. The percentage of eyes with intraocular pressure of 25 mm Hg or more peaked at 7.1% for the 0.7-mg DEX implant, 8.7% for the 0.35-mg DEX implant, and 4.2% for the sham (P > .05 at any visit). The incidence of cataract reported in the phakic eyes was 9 of 62 (15%) with the 0.7-mg DEX implant, 6 of 51 (12%) with the 0.35-mg DEX implant, and 4 of 55 (7%) with the sham (P > .05). CONCLUSIONS: In patients with noninfectious intermediate or posterior uveitis, a single DEX implant significantly improved intraocular inflammation and visual acuity persisting for 6 months. Application to Clinical Practice Dexamethasone intravitreal implant may be used safely and effectively for treatment of intermediate and posterior uveitis. Trial Registration clinicaltrials.gov Identifier: NCT00333814.