Dose reduction of epoetin-alpha in the prevention of chemotherapy-induced anaemia.

INTRODUCTION: Anaemia during chemotherapy is often left untreated. Erythropoiesis-stimulating agents are frequently used to treat overt anaemia. Their prophylactic use, however, remains controversial and raises concerns about cost-effectiveness. Therefore, we assessed the efficacy of a dose-reduction schedule in anaemia prophylaxis. MATERIALS AND METHODS: The study included patients with untreated solid tumours about to receive platinum-based chemotherapy and had haemoglobin (Hb) levels ≥11 g/dL. Epoetin-α was administered at a dose level of 3 × 10,000 U weekly as soon as Hb descended to < 13 g/dL. Dose reductions to 3 × 4,000 U and 3 × 2,000 U weekly were planned in 4-week intervals if Hb stabilised in the range of 11-13 g/dL. Upon ascending to ≥13 g/dL, epoetin was discontinued. Iron supplements of 100 mg intravenous doses were given weekly. Of 37 patients who enrolled, 33 could be evaluated. RESULTS AND DISCUSSION: Their median Hb level was 13.7 (10.9-16.2) g/dL at baseline and descended to 11.0 (7.4-13.8) g/dL by the end of chemotherapy. Anaemia (Hb < 10 g/dL) was prevented in 24 patients (73%). The mean dose requirement for epoetin-α was 3 × 5,866 U per week per patient, representing a dose reduction of 41%. Treatment failed in nine patients (27%), in part due to epoetin-α resistance in four (12%) and blood transfusion in three (9%) patients. CONCLUSION: Dose reduction was as effective as fixed doses in anaemia prophylaxis but reduced the amount of prescribed epoetin substantially.

An introductory review on gravitational-deformation induced structures, fabrics and modeling

Recent studies have pointed out a similarity between tectonics and slope tectonic-induced structures. Numerous studies have demonstrated that structures and fabrics previously interpreted as of purely geodynamical origin are instead the result of large slope deformation, and this led in the past to erroneous interpretations. Nevertheless, their limit seems not clearly defined, but it is somehow transitional. Some studies point out continuity between failures developing at surface with upper crust movements. In this contribution, the main studies which examine the link between rock structures and slope movements are reviewed. The aspects regarding model and scale of observation are discussed together with the role of pre-existing weaknesses in the rock mass. As slope failures can develop through progressive failure, structures and their changes in time and space can be recognized. Furthermore, recognition of the origin of these structures can help in avoiding misinterpretations of regional geology. This also suggests the importance of integrating different slope movement classifications based on distribution and pattern of deformation and the application of structural geology techniques. A structural geology approach in the landslide community is a tool that can greatly support the hazard quantification and related risks, because most of the physical parameters, which are used for landslide modeling, are derived from geotechnical tests or the emerging geophysical approaches.

Ceftriaxone acts synergistically with levofloxacin in experimental meningitis and reduces levofloxacin-induced resistance in penicillin-resistant pneumococci.

Ceftriaxone acted synergistically with levofloxacin in time-killing assays in vitro over 8 h against two penicillin-resistant pneumococcal strains (WB4 and KR4; MIC of penicillin: 4 mg/L). Synergy was confirmed with the chequerboard method, showing FIC indices of 0.25. In the experimental rabbit meningitis model, ceftriaxone (1x 125 mg/kg) was slightly less bactericidal (-0.30 Deltalog(10) cfu/mL(.)h) compared with levofloxacin (-0.45 Deltalog(10) cfu/mL(.)h) against the penicillin-resistant strain WB4. The combination therapy (levofloxacin and ceftriaxone) was significantly superior (-0.64 Deltalog(10) cfu/mL(.)h) to either monotherapy. In cycling experiments in vitro, the addition of ceftriaxone at a sub-MIC concentration (1/16 MIC) reduced levofloxacin-induced resistance in the two strains KR4 and WB4. After 12 cycles with levofloxacin monotherapy, the MIC increased 64-fold in both strains versus a 16-fold increase with the combination (levofloxacin + ceftriaxone 1/16 MIC). In both strains, levofloxacin-induced resistance was confirmed by mutations detected in the genes parC and gyrA, encoding for subunits of topoisomerase IV and gyrase, respectively. The addition of ceftriaxone suppressed mutations in parC but led to a new mutation in parE in both strains.

Protection from radiation-induced colitis requires MHC class II antigen expression by cells of hemopoietic origin.

Ulcerative colitis, an inflammatory bowel disease, is believed to result from a breakdown of dominant tolerance mechanisms that normally control intestinal immunity. Although CD4+ T lymphocyte subpopulations and expression of MHC class II molecules have been shown to play a role in the pathogenesis of the disease, the nature of the responsible mechanisms remains unclear. In this paper we describe a novel mouse model for inflammatory bowel disease, radiation-induced colitis, that occurs with complete penetrance 6-8 wk postinduction. A combination of high dose gamma-irradiation and lack of MHC class II expression on cells of hemopoietic origin results in development of colitis in C57BL/6 mice. Because of its versatility (due to susceptibility of mice of the widely genetically manipulated C57BL/6 background), high reproducibility, and 100% penetrance, radiation-induced colitis will be a useful mouse model for colitis and a significant tool to study dominant immunological tolerance mechanisms. Moreover, our data imply that tolerization to enteric Ags requires MHC class II mediated presentation by APC of hemopoietic origin.

A pea plasma membrane protein exhibiting blue light-induced phosphorylation retains photosensitivity following triton solubilization.

Phosphorylation of a polypeptide of approximately 120 kD in pea (Pisum sativum L.) plasma membranes in response to blue light has been shown to be involved in phototropic curvature, but the relationship of this protein to the kinase and photoreceptor acting upon it is uncertain. Using two-phase aqueous partitioning to isolate right-side-out plasma membrane vesicles, we have obtained evidence suggesting that the photoreceptor, kinase, and substrate are localized to the plasma membrane fraction. Latent phosphorylation accessible through Triton X-100 or freeze/thaw treatments of purified plasma membrane vesicles indicates that at least the kinase moiety is present on the internal face of the plasma membrane. Effects of solubilization of vesicles on fluence-response characteristics and on phosphorylation levels provide evidence that the receptor, kinase, and protein substrate are present together in individual mixed detergent micelles, either as a stable complex or as domains of a single polypeptide. In vivo blue-light irradiation results in a small but significant decrease in mobility of the 120-kD phosphorylated protein on sodium dodecylsulfate gel electrophoresis. This mobility shift is evident on Coomassie-stained gels and on western blots probed with polyclonal antibodies raised against the 120-kD protein. Among the plasma membrane proteins bound to the reactive nucleotide analog fluorosulfonylbenzoyladenine (FSBA), a distinct protein band at 120 kD can be detected on blots probed with anti-FSBA antibodies. This band exhibits an in vivo light-dependent mobility shift identical to that observed for the protein band and antibodies specific for the 120-kD protein, implying that the 120-kD protein has an integral nucleotide binding site and consistent with the possibility that the substrate protein is also a kinase.

The pattern and Loci of training-induced brain changes in healthy older adults are predicted by the nature of the intervention.

There is enormous interest in designing training methods for reducing cognitive decline in healthy older adults. Because it is impaired with aging, multitasking has often been targeted and has been shown to be malleable with appropriate training. Investigating the effects of cognitive training on functional brain activation might provide critical indication regarding the mechanisms that underlie those positive effects, as well as provide models for selecting appropriate training methods. The few studies that have looked at brain correlates of cognitive training indicate a variable pattern and location of brain changes - a result that might relate to differences in training formats. The goal of this study was to measure the neural substrates as a function of whether divided attentional training programs induced the use of alternative processes or whether it relied on repeated practice. Forty-eight older adults were randomly allocated to one of three training programs. In the SINGLE REPEATED training, participants practiced an alphanumeric equation and a visual detection task, each under focused attention. In the DIVIDED FIXED training, participants practiced combining verification and detection by divided attention, with equal attention allocated to both tasks. In the DIVIDED VARIABLE training, participants completed the task by divided attention, but were taught to vary the attentional priority allocated to each task. Brain activation was measured with fMRI pre- and post-training while completing each task individually and the two tasks combined. The three training programs resulted in markedly different brain changes. Practice on individual tasks in the SINGLE REPEATED training resulted in reduced brain activation whereas DIVIDED VARIABLE training resulted in a larger recruitment of the right superior and middle frontal gyrus, a region that has been involved in multitasking. The type of training is a critical factor in determining the pattern of brain activation.

Cannabis use in a Swiss male prison: qualitative study exploring detainees' and staffs' perspectives.

BACKGROUND: Several studies suggest a high prevalence of cannabis use before and during imprisonment, but subjective perspectives of detainees and staff towards its use in prison are lacking. This issue was explored in the framework of an observational study addressing tobacco use in three Swiss prisons in 2009 and 2010 that involved multiple strands (quantitative and qualitative components). This article presents qualitative data on cannabis use collected in one of the settings. METHODS: We used in-depth semi-structured interviews with both detainees and staff to explore their attitudes towards cannabis in one post-trial male Swiss prison. We performed specific coding and thematic analysis for cannabis with the support of ATLAS.ti, compared detainees' and staff's opinions, and considered the results with regard to drug policy in prison in general. RESULTS: 58 participants (31 male offenders, mean age 35 years, and 27 prison staff, mean age 46 years, 33% female) were interviewed. Detainees estimated the current use of cannabis use to be as high as 80%, and staff 50%. Participants showed similar opinions on effects of cannabis use that were described both at individual and institutional levels: analgesic, calming, self-help to go through the prison experience, relieve stress, facilitate sleep, prevent violence, and social pacifier. They also mentioned negative consequences of cannabis use (sleepiness, decreased perception of danger and social isolation), and dissatisfaction regarding the ongoing ambiguous situation where cannabis is forbidden but detection in the urine was not sanctioned. However, the introduction of a more restrictive regulation induced fear of violence, increased trafficking and a shift to other drug use. CONCLUSION: Although illegal, cannabis use is clearly involved in daily life in prison. A clearer and comprehensive policy addressing cannabis is needed, including appropriate measures tailored to individual users. To sustain a calm and safe environment in prison, means other than substance or medication use are required.

Insulinoma associated with a case of multiple endocrine neoplasia type I: Functional somatostatin receptors and abnormal glucose-induced insulin secretion.

A sporadic case of multiple endocrine neoplasia type I with coexisting insulinoma and hyperparathyroidism was investigated in vivo and in vitro. The insulinoma was localized by somatostatin receptor scintigraphy and these receptors were functionally active. Octreotide administration decreased the basal insulin and glucagon secretion by 90 and 46%, respectively. Immunocytochemistry of the insulinoma tissue was positive for insulin, chromogranin A and neuropeptide Y. The insulinoma cells were also isolated and cultured in vitro. Incubation experiments revealed that a low glucose concentration (1 mmol/l) was sufficient to increase cytosolic free calcium and to produce a maximal glucose-induced insulin release. Northern blot analysis of RNA obtained from the tumor showed a high abundance of the low Km glucose transporter GLUT1 but no transcript for the high Km glucose transporter GLUT2. The abnormal distribution of glucose transporters probably relates to the abnormal glucose sensing of insulinoma cells, and explains their sustained insulin secretion at low glucose concentrations. Whether these abnormalities share a pathogenetic link with the presence of functionally active somatostatin receptors remains to be elucidated.

Basal and antigen-induced exposure of the proline-rich sequence in CD3ε.

The CD3ε cytoplasmic tail contains a conserved proline-rich sequence (PRS) that influences TCR-CD3 expression and signaling. Although the PRS can bind the SH3.1 domain of the cytosolic adapter Nck, whether the PRS is constitutively available for Nck binding or instead represents a cryptic motif that is exposed via conformational change upon TCR-CD3 engagement (CD3Δc) is currently unresolved. Furthermore, the extent to which a cis-acting CD3ε basic amino acid-rich stretch (BRS), with its unique phosphoinositide-binding capability, might impact PRS accessibility is not clear. In this study, we found that freshly harvested primary thymocytes expressed low to moderate basal levels of Nck-accessible PRS ("open-CD3"), although most TCR-CD3 complexes were inaccessible to Nck ("closed-CD3"). Ag presentation in vivo induced open-CD3, accounting for half of the basal level found in thymocytes from MHC(+) mice. Additional stimulation with either anti-CD3 Abs or peptide-MHC ligands further elevated open-CD3 above basal levels, consistent with a model wherein antigenic engagement induces maximum PRS exposure. We also found that the open-CD3 conformation induced by APCs outlasted the time of ligand occupancy, marking receptors that had been engaged. Finally, CD3ε BRS-phosphoinositide interactions played no role in either adoption of the initial closed-CD3 conformation or induction of open-CD3 by Ab stimulation. Thus, a basal level of open-CD3 is succeeded by a higher, induced level upon TCR-CD3 engagement, involving CD3Δc and prolonged accessibility of the CD3ε PRS to Nck.

Neuroendocrine characterization and anorexigenic effects of telmisartan in diet- and glitazone-induced weight gain.

Telmisartan is an angiotensin II receptor blocker with peroxisome proliferator-activated receptor-gamma agonistic properties. Telmisartan prevents weight gain and decreases food intake in models of obesity and in glitazone-treated rodents. This study further investigates the influence of telmisartan and pioglitazone and their association on weight gain and body composition by examining their influence on neuroendocrine mediators involved in food intake. Male C57/Black 6 mice were fed a high-fat diet, weight matched, and randomized in 4 treatment groups: vehicle, pioglitazone, telmisartan, and pioglitazone-telmisartan. Weight gain, food and water intake, body composition, plasma leptin levels, and the hypothalamic expression of neuroendocrine mediators were analyzed. Additional studies were performed with irbesartan and in angiotensin II 1(A) receptor-knockout mice. Telmisartan abolished weight and fat gain in vehicle- and pioglitazone-treated mice while decreasing food intake, the hypothalamic expression of the agouti-related protein, and plasma leptin levels. Modifications in neuropeptide Y and proopiomelanocortin were not consistent with changes in food intake. The effects on weight gain and expression of the agouti-related protein were intermediate with irbesartan. The effects of telmisartan on weight gain were even more pronounced in angiotensin II 1(A) receptor-knockout mice. This study confirms the anorexigenic effects of telmisartan in mice fed a high-fat diet and suggests for the first time a functional role of telmisartan on hypothalamic orexigenic agouti-related protein regulation. These anorexigenic properties abolish both weight gain and body composition modifications in fat-fed and glitazone-treated mice. The anorexigenic properties are independent from the angiotensin II 1(A) receptor.

Moderate exercise blunts oxidative stress induced by normobaric hypoxic confinement

PURPOSE: Both acute hypoxia and physical exercise are known to increase oxidative stress. This randomized prospective trial investigated whether the addition of moderate exercise can alter oxidative stress induced by continuous hypoxic exposure. METHODS: Fourteen male participants were confined to 10-d continuous normobaric hypoxia (FIO2 = 0.139 +/- 0.003, PIO2 = 88.2 +/- 0.6 mm Hg, approximately 4000-m simulated altitude) either with (HCE, n = 8, two training sessions per day at 50% of hypoxic maximal aerobic power) or without exercise (HCS, n = 6). Plasma levels of oxidative stress markers (advanced oxidation protein products [AOPP], nitrotyrosine, and malondialdehyde), antioxidant markers (ferric-reducing antioxidant power, superoxide dismutase, glutathione peroxidase, and catalase), nitric oxide end-products, and erythropoietin were measured before the exposure (Pre), after the first 24 h of exposure (D1), after the exposure (Post) and after the 24-h reoxygenation (Post + 1). In addition, graded exercise test in hypoxia was performed before and after the protocol. RESULTS: Maximal aerobic power increased after the protocol in HCE only (+6.8%, P < 0.05). Compared with baseline, AOPP was higher at Post + 1 (+28%, P < 0.05) and nitrotyrosine at Post (+81%, P < 0.05) in HCS only. Superoxide dismutase (+30%, P < 0.05) and catalase (+53%, P < 0.05) increased at Post in HCE only. Higher levels of ferric-reducing antioxidant power (+41%, P < 0.05) at Post and lower levels of AOPP (-47%, P < 0.01) at Post + 1 were measured in HCE versus HCS. Glutathione peroxidase (+31%, P < 0.01) increased in both groups at Post + 1. Similar erythropoietin kinetics was noted in both groups with an increase at D1 (+143%, P < 0.01), a return to baseline at Post, and a decrease at Post + 1 (-56%, P < 0.05). CONCLUSIONS: These data provide evidence that 2 h of moderate daily exercise training can attenuate the oxidative stress induced by continuous hypoxic exposure.

Bicc1 links the regulation of cAMP signaling in polycystic kidneys to microRNA-induced gene silencing.

Genetic defects in autosomal-dominant polycystic kidney disease (ADPKD) promote cystic growth of renal tubules, at least in part by stimulating the accumulation of cAMP. How renal cAMP levels are regulated is incompletely understood. We show that cAMP and the expression of its synthetic enzyme adenylate cyclase-6 (AC6) are up-regulated in cystic kidneys of Bicc1(-)(/-) knockout mice. Bicc1, a protein comprising three K homology (KH) domains and a sterile alpha motif (SAM), is expressed in proximal tubules. The KH domains independently bind AC6 mRNA and recruit the miR-125a from Dicer, whereas the SAM domain enables silencing by Argonaute and TNRC6A/GW182. Bicc1 similarly induces silencing of the protein kinase inhibitor PKIα by miR-27a. Thus, Bicc1 is needed on these target mRNAs for silencing by specific miRNAs. The repression of AC6 by Bicc1 might explain why cysts in ADPKD patients preferentially arise from distal tubules.

A Novel Pulse-Chase SILAC Strategy Measures Changes in Protein Decay and Synthesis Rates Induced by Perturbation of Proteostasis with an Hsp90 Inhibitor.

Standard proteomics methods allow the relative quantitation of levels of thousands of proteins in two or more samples. While such methods are invaluable for defining the variations in protein concentrations which follow the perturbation of a biological system, they do not offer information on the mechanisms underlying such changes. Expanding on previous work [1], we developed a pulse-chase (pc) variant of SILAC (stable isotope labeling by amino acids in cell culture). pcSILAC can quantitate in one experiment and for two conditions the relative levels of proteins newly synthesized in a given time as well as the relative levels of remaining preexisting proteins. We validated the method studying the drug-mediated inhibition of the Hsp90 molecular chaperone, which is known to lead to increased synthesis of stress response proteins as well as the increased decay of Hsp90 "clients". We showed that pcSILAC can give information on changes in global cellular proteostasis induced by treatment with the inhibitor, which are normally not captured by standard relative quantitation techniques. Furthermore, we have developed a mathematical model and computational framework that uses pcSILAC data to determine degradation constants kd and synthesis rates Vs for proteins in both control and drug-treated cells. The results show that Hsp90 inhibition induced a generalized slowdown of protein synthesis and an increase in protein decay. Treatment with the inhibitor also resulted in widespread protein-specific changes in relative synthesis rates, together with variations in protein decay rates. The latter were more restricted to individual proteins or protein families than the variations in synthesis. Our results establish pcSILAC as a viable workflow for the mechanistic dissection of changes in the proteome which follow perturbations. Data are available via ProteomeXchange with identifier PXD000538.