Disulfide cross-linking of subunits F1-γ and F0I-PVP(b) results in asymmetric effects on proton translocation in the mitochondrial ATP synthase.

AbstractA study is presented on the effect of diamide-induced disulfide cross-linking of F1-γ and F0I-PVP(b) subunits on proton translocation in the mitochondrial ATP synthase. The results show that, upon cross-linking of these subunits, whilst proton translocation from the A side to the B F1 side is markedly accelerated with decoupling of oxidative phosphorylation, proton translocation in the reverse direction, driven by either ATP hydrolysis or a diffusion potential, is unaffected. These observations reveal further peculiarities of the mechanism of energy transfer in the ATP synthase of coupling membranes

Role of targeted agents in neuroendocrine tumors: Results from a meta-analysis

5noBACKGROUND: Several randomized phase III trials in neuroendocrine tumors (NETs) showed the clinical role of new targeted agents and their impact on tumor response and outcome of whose patients affected by advanced NET. In this study, we summarize the available clinical data related to clinical efficacy of targeted therapies in the treatment of advanced NETs. METHODS: A meta-analysis of randomized studies in accordance with the PRISMA guidelines was performed after searching the databases of PubMed, the Cochrane Library, and the ASCO University Meeting for relevant publications. RESULTS: One thousand 9 hundred and 8 cases were included in the meta-analysis; among these, 1012 were in the experimental arm and 896 were in the control arm. The pooled analysis of the use of target agents in NETs revealed significantly increased of progression free survival compared to control group (hazard ratio = 0.59, 95% CI:0.42-0.84; P = 0.003). Subgroup analysis of patients according to tumor site showed a difference in favor of pancreatic neuroendocrine tumors. Moreover, targeted therapies improved the overall survival (hazard ratio = 0.79, 95%CI: 0.63-0.98; P = 0.03), and response rate (hazard ratio = 3.33, 95% CI 2.02-5.49; P < 0.00001) in all types of NETs. CONCLUSION: Our analysis supports the routine use of targeted agents for treatment of neuroendocrine tumors with particular regards to the pancreatic neuroendocrine tumorspartially_openembargoed_20171001Roviello, Giandomenico; Zanotti, Laura; Venturini, Sergio; Bottini, Alberto; Generali, DanieleRoviello, Giandomenico; Zanotti, Laura; Venturini, Sergio; Bottini, Alberto; Generali, Daniel

Identification of nucleus-encoded F0I protein of bovine heart mitochondrial H+-ATPase as a functional part of the F0 moiety

AbstractThe F0I protein of apparent Mr 27000, previously characterized [(1988) Eur. J. Biochem. 173, 1–8] as a genuine component of bovine heart F0, has been sequenced and shown to be identical with the nucleus encoded 24668 Da protein characterized earlier [(1987) J. Mol. Biol. 197, 89–100]. It is directly shown by proteolytic cleavage and reconstitution experiments that this protein, denoted here as PVP from the single-letter codes of the last three residues of the N-terminus, is involved in proton conduction by F0 and in its sensitivity to oligomycin

Preload-independent mechanisms contribute to increased stroke volume following large volume saline infusion in normal volunteers: a prospective interventional study

INTRODUCTION: Resuscitation with saline is a standard initial response to hypotension or shock of almost any cause. Saline resuscitation is thought to generate an increase in cardiac output through a preload-dependent (increased end-diastolic volume) augmentation of stroke volume. We sought to confirm this to be the mechanism by which high-volume saline administration (comparable to that used in resuscitation of shock) results in improved cardiac output in normal healthy volunteers. METHODS: Using a standardized protocol, 24 healthy male (group 1) and 12 healthy mixed sex (group 2) volunteers were infused with 3 l normal (0.9%) saline over 3 hours in a prospective interventional study. Individuals were studied at baseline and following volume infusion using volumetric echocardiography (group 1) or a combination of pulmonary artery catheterization and radionuclide cineangiography (group 2). RESULTS: Saline infusion resulted in minor effects on heart rate and arterial pressures. Stroke volume index increased significantly (by approximately 15–25%; P < 0.0001). Biventricular end-diastolic volumes were only inconsistently increased, whereas end-systolic volumes decreased almost uniformly. Decreased end-systolic volume contributed as much as 40–90% to the stroke volume index response. Indices of ventricular contractility including ejection fraction, ventricular stroke work and peak systolic pressure/end-systolic volume index ratio all increased significantly (minimum P < 0.01). CONCLUSION: The increase in stroke volume associated with high-volume saline infusion into normal individuals is not only mediated by an increase in end-diastolic volume, as standard teaching suggests, but also involves a consistent and substantial decrease in end-systolic volumes and increases in basic indices of cardiac contractility. This phenomenon may be consistent with either an increase in biventricular contractility or a decrease in afterload

Mitochondrial F0F1 H+-ATP synthase Characterization of F0 components involved in H+ translocation

AbstractThe membrane F0, sector of mitochondrial ATP synthase complex was rapidly isolated by direct extraction with CHAPS from F1-depleted submitochondrial particles. The preparation thus obtained is stable and can be reconstituted in artificial phospholipid membranes to result in oligomycin-sensitive proton conduction, or recombined with purified F1 to give the oligomycin-sensitive F0F1-ATPase complex. The F0 preparation and constituent polypeptides were characterized by SDS-polyacrylamide gel electrophoresis and immunoblot analysis. The functional role of F0 polypeptides was examined by means of trypsin digestion and reconstitution studies. It is shown that, in addition to the 8 kDa DCCD-binding protein, the nuclear encoded protein [(1987) J. Mol. Biol. 197, 89–100], characterized as an intrinsic component of F0, (F0I, PVP protein [(1967) J. Biol. Chem. 242, 2547–2551]) is involved in H+ translocation and the sensitivity of this process to the F0 inhibitors, DCCD and oligomycin

Multiple large osteolytic lesions in a patient with systemic mastocytosis: a challenging diagnosis

Patients with advanced variants of Systemic Mastocytosis may develop destructive bone lesions when massive mast cell (MC) infiltrates are present. Finding of large osteolyses in indolent systemic mastocytosis, typically characterized by low MC burden, should prompt investigations for an alternative explanation

Evaluation of a novel human IgG1 anti-claudin3 antibody that specifically recognizes its aberrantly localized antigen in ovarian cancer cells and that is suitable for selective drug delivery

Membrane protein claudin3 has been recently suggested as a marker for biologically aggressive tumors and a possible target for the therapeutic delivery of active anti-cancer compounds. Claudin3-binding molecules such as the Clostridium perfringens enterotoxin (CPE), CPE-related molecules, and murine and chimeric antibodies have shown promising antitumor efficacy in preclinical oncological settings. We first engineered a fully human anti-claudin3 IgG1 antibody (IgGH6) by fusing the human IgG1 Fc-domain to the anti-claudin3 scFvH6 previously isolated from a pre-immune phage display library. The construct was expressed in mammalian cells and specifically targeted claudin3 endogenously expressed on the surface of different human ovarian cancer cell lines. No detectable cross-reactivity with other homologous claudins was observed. The epitope recognized by IgGH6 is located within the minor extracellular domain of claudin3 and becomes accessible only in tumor cells characterized by incomplete junction formation. Confocal microscopy experiments demonstrated that IgGH6 was actively internalized in tumor cells after binding to native claudin3 and co-localized, likely within intracellular vesicles, with the C-CPE peptide. Preliminary results indicate that IgGH6 accumulated in vivo in free claudin3 ovarian carcinoma xenografts. For its selective uptake in tumor cells and its human nature, IgGH6 represents a valuable candidate for antibody-drug conjugate therapeutic applications in ovarian cancer patients

Caracterização e ocorrência do distúrbio do amolecimento precoce em mamões 'Golden'

The occurrence of green skin and soft pulp in 'Golden' papaya fruit during certain seasons has been reported by farmers in the northern of the state of Espirito Santo, Brazil. The objective of this study was to characterize and determine the occurrence of this disorder, which was referred as "early softening disorder". Fruits were harvested weekly for 11 months (from September to July). The fruits were stored at 10°C, and then fruit flesh firmness and skin color were analyzed. The results of the firmness test were submitted to regression analysis assuming a linear trendline. The slope of the curve was called the 'softening index' (SI). Fruits with early softening are characterized by a loss of firmness in less than 10 days, even when stored under refrigeration. Although softened, the skin of the fruit remains partially green. Fruits with the disorder occurred more frequently from mid-summer to mid-autumn (February to May). It is not possible to distinguish early softening disorder fruits from those without the disorder by skin color and flesh firmness analysis at the time of the harvest.Tem sido relatado por produtores da região norte do Espírito Santo a ocorrência de mamões 'Golden' com casca verde e polpa mole, em determinadas épocas do ano. O objetivo deste trabalho foi caracterizar e determinar a ocorrência deste distúrbio denominado de amolecimento precoce. Foram realizadas coletas semanais durante 11 meses (período de setembro a julho). Os frutos foram armazenados a 10°C e analisados quanto à firmeza da polpa e à cor da casca. Os resultados de firmeza da polpa foram submetidos à análise de regressão, assumindo-se que a equação é do tipo linear, e o ângulo de inclinação da curva foi chamado Índice de Amolecimento (IA). Frutos com o distúrbio caracterizaram-se pela perda da firmeza em menos de 10 dias, mesmo quando armazenados sob refrigeração. Embora amolecidos, a coloração da casca manteve-se parcialmente verde. A maior frequência de frutos com o distúrbio ocorreu de meados de verão a meados de outono (fevereiro a maio). Não é possível distinguir frutos com o distúrbio do amolecimento precoce daqueles normais pela análise da cor da casca e da firmeza da polpa, no momento da colheita