997 resultados para PHYSIOLOGICAL INHIBITORS


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Objective: To investigate the association between angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) and disease progression and survival in cancer patients.

Methods: Using terms for cancer and ACEIs/ARBs, MEDLINE, EMBASE and Web of Science were systematically searched for observational/interventional studies that used clinically relevant outcomes for cancer progression and survival.

Results: Ten studies met the inclusion criteria. Two studies showed a significant improvement in overall survival (OS) with ACEI/ARB use among patients with advanced pancreatic (HR 0.52, 95% CI 0.29–0.88) and non-small cell lung cancer (HR 0.56, 95% CI 0.33–0.95). An improvement in progression-free survival (PFS) was also reported for pancreatic cancer patients (HR 0.58, 95% CI 0.34–0.95) and patients with renal cell carcinoma (HR 0.54, p = 0.02). ACEI/ARB use was protective against breast cancer recurrence (HR 0.60, 95% CI 0.37–0.96), colorectal cancer distant metastasis (OR 0.22, 95% CI 0.08–0.65) and prostate specific antigen (PSA) failure in prostate cancer patients (p = 0.034). One study observed a worse OS (HR 2.01, 95% CI 1.00–4.05) and PFS in ACEI users with multiple myeloma (p = 0.085) while another reported an increased risk of breast cancer recurrence (HR = 1.56, 95% CI 1.02–2.39).

Conclusion: There is some evidence to suggest that ACEI or ARB use may be associated with improved outcomes in cancer patients. Larger, more robust studies are required to explore this relationship further.

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Inhibitors of Gly transporter type-1 (GlyT1) for the treatment of schizophrenia have been pursued on the basis of the NMDA receptor (R) hypofunction hypothesis, which stems largely from the observation that NMDAR antagonists induce symptoms that more closely mimic those characteristic of schizophrenia than do other classes of psychotic agents. GlyT1 is responsible for uptake of synaptic Gly, an NMDAR co-agonist amino acid, in neuronal populations throughout the forebrain. GlyT1 inhibition thereby potentiates NMDAR activity by increasing synaptic Gly levels. Correspondingly, a large body of data suggests that GlyT1 inhibitors likely confer more comprehensive symptom alleviation than current antipsychotics. To date, a number of small-molecule GlyT1 inhibitors have been reported by the pharmaceutical industry. Developments in the discovery and characterization of GlyT1 inhibitors are discussed in this review.

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Couvade is the male experience of pregnancy and couvade syndrome incorporates a range of symptoms suffered by ''pregnant'' men. The aetiology of the couvade syndrome is unknown. Anthropologists, psychiatrists, nurses and sociologists have provided explanations for behaviour changes in ''pregnant'' men in terms of cultural pressure, intrapsychic processes and psychosocial adaptation to a new situation. The adoption of a biological perspective allows us to ask a new question: is there a physiological basis for the couvade syndrome? A fresh research agenda would include measurement of physiological change and a search for causation. Implications for nursing are outlined.

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The effect of the microtubule inhibitors colchicine (1 x 10(-3) M) and tubulozole-C(1 x 10(-6) M) on the ultrastructure of adult Fasciola hepatica has been determined in vitro by transmission electron microscopy (TEM), using both intact flukes and tissue-slice material. With colchicine treatment, the apical membrane of the tegument became increasingly convoluted and blebbed, while accumulations of T1 secretory bodies occurred in the basal region of the syncytium, leading to progressively fewer secretory bodies in the syncytium. In the tegumental cells there were distinct accumulations of Tl secretory bodies around the Golgi complexes, which remained active for up to 12 h incubation. Tubulozole-treated flukes showed more severe effects, with initial accumulations of secretory bodies, both at the tegumental apex and base. This was followed in the later time-periods by the sloughing of the tegumental syncytium. In the underlying tegumental cells, the granular endoplasmic reticulum (GER) cisternae were swollen and disrupted, becoming concentrated around the nucleus. The Golgi complexes were dispersed to the periphery of the cells and gradually disappeared from the cytoplasm. After treatment with both drugs, the cell population in the vitelline follicles was altered, with an abnormally large proportion of stem cells and relatively few intermediate type 1 cells. The nurse cell cytoplasm became fragmented and was no longer in contact with the vitelline cells, while the shell globule clusters within the intermediate type 2 and mature cells were loosely packed. In the mature vitelline cells, 'yolk' globules and glycogen deposits became fewer than normal and lipid droplets were observed. The results are discussed in relation to the different modes of action of the two drugs and potential significance of this to anthelmintic (benzimidazole) therapy.

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Rates of rapair of pBR 322 plasmid DNA radicals by thiols of varying net charge (Z) at pH 7 and physiological ionic strength were measured using the oxygen explosion technique. The extent of conversion of supercoiled to relaxed circular plasmid was measured by HPLC as a function of the time of oxygen exposure before or after irradiation, the time-courses being fitted by a pseudo-first-order kinetic expression with k1 = k2[RSH]. Values of k2 (M-1 S-1) were: 2.1 x 10(5) (GSH, Z = -1), 1.4 x 10(6) (2-mercaptoethanol, Z = 0), 1.2 x 10(7) (cysteamine, Z = +1), 6.6 x 10(7) (WR-1065 or N-(2-mercaptoethyl)-1,3-diamino?? propane, Z = +2). The approximately 6-fold increase in rate with each unit increase in Z is attributed to concentration of cationic thiols near DNA as a consequence of counter-ion condensation and reduced levels of anionic thiols near DNA owing to co-ion depletion. The results are quantitatively consistent with chemical repair as a significant mechanism for radioprotection of cells by neutral and cationic thiols under aerobic conditions, but indicate that repair by GSH will compete effectively with oxygen only at low oxygen tension.

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The actions of known platyhelminth FaRPs on the contractility of whole-worm preparations of the monogenean, Diclidophora merlangi have been examined in vitro for the first time. All of the peptides tested had excitatory effects on the motor activity of the worm. The order of potency for the peptides tested was: YIRFamide > GYIRFamide = RYIRFamide > GNFFRFamide = FLRFamide. However, although YIRFamide was more potent than GYIRFamide, the latter was the most efficacious on each of the motility parameters (tension, contraction amplitude and contraction frequency) examined at concentrations greater than or equal to 0.1 mu M. Serotonin, which stimulates contractility in the worm was used as a positive control. The excitatory activity of turbellarian and cestode neuropeptides on a monogenean indicates at least some structural similarities in the neuropeptide receptors of these classes of flatworm.

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The effects of each of the known platyhelminth neuropeptides were determined on muscle-strip preparations from the liver fluke, Fasciola hepatica. The activity of synthetic replicates of the C-terminal nonapeptide of neuropeptide F (NPF9, Moniezia expansa), and the FMRFamide-related peptides (FaRPs), GNFFRFamide, RYIRFamide, GYIRFamide and YIRFamide, were examined. Muscle-strip activity was recorded from 1 mm segments of muscle prepared from 28 to 32-day-old worms, using a photo-optic transducer system. None of the peptides (less than or equal to 10 mu M) altered baseline tension significantly; however, each of the peptides increased the amplitude and frequency of muscle contraction. The threshold for activity of each of the peptides examined was, respectively, 1 nM (RYIRFamide), 0.3 mu M (GYIRFamide and YIRFamide), and 10 mu M (GNFFRFamide and NPF9). All of the effects were reversible and repeatable, following wash-out. Muscle-strip integrity was tested following experimentation, using arecoline (10 mu M) and high-K+ bathing medium (90 mM K+).

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Artifact removal from physiological signals is an essential component of the biosignal processing pipeline. The need for powerful and robust methods for this process has become particularly acute as healthcare technology deployment undergoes transition from the current hospital-centric setting toward a wearable and ubiquitous monitoring environment. Currently, determining the relative efficacy and performance of the multiple artifact removal techniques available on real world data can be problematic, due to incomplete information on the uncorrupted desired signal. The majority of techniques are presently evaluated using simulated data, and therefore, the quality of the conclusions is contingent on the fidelity of the model used. Consequently, in the biomedical signal processing community, there is considerable focus on the generation and validation of appropriate signal models for use in artifact suppression. Most approaches rely on mathematical models which capture suitable approximations to the signal dynamics or underlying physiology and, therefore, introduce some uncertainty to subsequent predictions of algorithm performance. This paper describes a more empirical approach to the modeling of the desired signal that we demonstrate for functional brain monitoring tasks which allows for the procurement of a ground truth signal which is highly correlated to a true desired signal that has been contaminated with artifacts. The availability of this ground truth, together with the corrupted signal, can then aid in determining the efficacy of selected artifact removal techniques. A number of commonly implemented artifact removal techniques were evaluated using the described methodology to validate the proposed novel test platform. © 2012 IEEE.

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Patients attending for diagnostic oesophagogastroduodenoscopy (OGD) for dyspeptic symptoms are often receiving acid-suppression therapy that has not been discontinued prior to endoscopy, and this may reduce the diagnostic yield of endoscopy. The aim of this study was to compare the diagnostic yield of OGD in uncomplicated dyspepsia in patients receiving no medication, those receiving acid-suppression therapy, and those receiving nonsteroidal anti-inflammatory drugs (NSAIDs) at the time of endoscopy.