Day: 01/25/2011

X chromosome and suicide

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Suicide completion rates are significantly higher in males than females in most societies. Although gender differences in suicide rates have been partially explained by environmental and behavioral factors, it is possible that genetic factors, through differential expression between genders, may also help explain gender moderation of suicide risk. This study investigated X-linked genes in suicide completers using a two-step strategy. We first took advantage of the genetic structure of the French-Canadian population and genotyped 722 unrelated French-Canadian male subjects, of whom 333 were suicide completers and 389 were non-suicide controls, using a panel of 37 microsatellite markers spanning the entire X chromosome. Nine haplotype windows and several individual markers were associated with suicide. Significant results aggregated primarily in two regions, one in the long arm and another in the short arm of chromosome X, limited by markers DXS8051 and DXS8102, and DXS1001 and DXS8106, respectively. The second stage of the study investigated differential brain expression of genes mapping to associated regions in Brodmann areas 8/9, 11, 44 and 46, in an independent sample of suicide completers and controls. Six genes within these regions, Rho GTPase-activating protein 6, adaptor-related protein complex 1 sigma 2 subunit, glycoprotein M6B, ribosomal protein S6 kinase 90 kDa polypeptide 3, spermidine/spermine N(1)-acetyltransferase 1 and THO complex 2, were found to be differentially expressed in suicide completers.

 

Mechanisms for acute stress-induced enhancement of glutamatergic transmission and working memory

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Corticosteroid stress hormones have a strong impact on the function of prefrontal cortex (PFC), a central region controlling cognition and emotion, though the underlying mechanisms are elusive. We found that behavioral stressor or short-term corticosterone treatment in vitro induces a delayed and sustained potentiation of the synaptic response and surface expression of N-methyl-D-aspartic acid receptors (NMDARs) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) in PFC pyramidal neurons through a mechanism depending on the induction of serum- and glucocorticoid-inducible kinase (SGK) and the activation of Rab4, which mediates receptor recycling between early endosomes and the plasma membrane. Working memory, a key function relying on glutamatergic transmission in PFC, is enhanced in acutely stressed animals through an SGK-dependent mechanism. These results suggest that acute stress, by activating glucocorticoid receptors, increases the trafficking and function of NMDARs and AMPARs through SGK/Rab4 signaling, which leads to the potentiated synaptic transmission, thereby facilitating cognitive processes mediated by the PFC.

source: nature molecular psychiatry

 

Fentanyl Pectin Nasal Spray (FPNS) in the treatment of breakthrough cancer pain

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This randomized, double-blind, crossover study assessed the efficacy and tolerability of a new rapid onset nasal fentanyl formulation (Fentanyl Pectin Nasal Spray; FPNS) for breakthrough cancer pain (BTCP). Eighty-three of 114 patients experiencing one to four BTCP episodes/day while taking >/=60 mg/day of oral morphine or equivalent successfully identified an effective dose of FPNS during a titration phase and entered a double-blind phase in which 10 BTCP episodes were treated with this effective dose (7) or placebo (3). Compared with placebo, FPNS significantly improved mean summed pain intensity difference (SPID) from 10 min (P<0.05) until 60 min (P<0.0001), including the primary endpoint at 30 min (P<0.0001). FPNS significantly improved pain intensity (PI) scores as early as 5 min (P<0.05); pain intensity difference (PID) from 10 min (P<0.01); and pain relief (PR) scores from 10 min (P<0.001). More patients showed a clinically meaningful (>/= 2-point reduction in PI) pain reduction from 10 min onward (P <= 0.01) and 90.6% of the FPNS-treated versus 80.0% of placebo-treated BTCP episodes did not require rescue medication (P<0.001). Approximately 70% of patients were satisfied or very satisfied with the convenience and ease of use of FPNS. Only 5.3% of patients withdrew from treatment due to adverse events, no significant nasal effects were reported, and 87% of patients elected to continue open-label treatment post-study. In this short-term study, FPNS was safe, well tolerated, and rapidly efficacious for BTCP.

Interventions for treating sexual dysfunction in patients with chronic kidney disease.

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Sexual dysfunction is very common in patients with chronic kidney disease (CKD), but it is still significantly understudied. Treatment options exist but concerns have been raised relating to their efficacy and safety in CKD.
OBJECTIVES: We assessed the benefits and harms of existing interventions for treatment of sexual dysfunction in patients with CKD.
SEARCH STRATEGY: In October 2010 we searched the Cochrane Renal Group`s specialised register, CENTRAL (The Cochrane Library, issue 10), MEDLINE (from 1966) and EMBASE (from 1980).
SELECTION CRITERIA: Randomised controlled trials (RCTs) and quasi-RCTs of any pharmacological and non-pharmacological interventions used to treat sexual dysfunction in male and female CKD patients (predialysis, dialysis and kidney transplant) were included.
DATA COLLECTION AND ANALYSIS: Two authors independently selected eligible studies, extracted data and assessed study quality. Disagreements were resolved in consultation with an arbitrator. Treatment effects were summarised as risk ratios (RR), mean differences (MD) or standardised mean difference (SMD) with 95% confidence intervals (CI) using a random-effects model.
MAIN RESULTS: Fifteen studies (8 parallel, 7 crossover; 352 patients) were included. Only one study enrolled women. Studies evaluated the effects of phosphodiesterase-5 inhibitors (PDE5i), zinc, vitamin E, vitamin D or bromocriptine compared to placebo. PDE5i significantly increased the overall International Index of Erectile Function-5 (IIEF-5) score (2 studies, 101 patients, MD 10.65, 95% CI 5.34 to 15.96), all its individual domains and the complete 15-item IIEF tool (1 study, 41 patients, MD 2.64, 95% CI 1.32 to 3.96). End of treatment testosterone levels were not significantly increased by addition of zinc to dialysate (2 studies, 22 patients, MD 0.21 ng/mL, 95% CI -2.14 to 2.55) but oral zinc improved end of treatment testosterone levels (1 study, 20 patients, SMD 1.62, 95% CI 0.58 to 2.66). There was no difference in plasma luteinizing and follicle-stimulating hormone levels at the end of the study period with zinc therapy. Only sparse data were available for vitamin E, bromocriptine and dihydroxycholecalciferol in CKD patients and there were no studies of intracavernous injections, transurethral injections, mechanical devices or psychosexual therapies in people with CKD.
AUTHORS’ CONCLUSIONS: PDE5i and zinc are promising interventions for treating sexual dysfunction in men with CKD. Evidence supporting their routine use in CKD patients is limited. There is an unmet need for studying interventions for both male and female sexual dysfunction in CKD, considering the significant disease burden.

source: cochrane database

Breast cancer stem cells

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Since the initial discovery of leukemia stem cells nearly a decade ago, a great deal of cancer research has focused on the identification of cancer stem cells (CSCs) in many types of solid tumors, including breast cancer. Through analysis of cell surface markers and xenotransplant models, a subpopulation of putative human breast cancer stem cells (BCSCs) that is CD24-negative/CD44-positive (CD24−/CD44+) and bears high aldehyde dehydrogenase 1 activity has been isolated in clinical samples of breast cancer tissues. Human BCSCs are considered to be derived from basal cells that reside in the basal membranes of alveolar units in human adult mammary glands. Furthermore, BCSCs have been shown to express higher levels of oxidative stress-responsive genes, which could confer part of their ability to resist anti-cancer therapy, than non-CSCs. The emerging picture of the biological properties of BCSCs would contribute for devising innovative therapies for breast cancer, targeting the intrinsic and extrinsic factors that maintain the BCSCs.

 

Behavioral Therapy Prevents Recurrences of Cardiovascular Events in Trial

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Cognitive-behavioral therapy, with a focus on stress management, is associated with fewer recurrent cardiovascular events in patients with coronary heart disease, according to an Archives of Internal Medicine study.

Some 350 adults who had recently had a coronary heart disease event were randomized to either usual care alone or usual care plus cognitive-behavioral therapy. Psychologists and nurses led 20 2-hour group sessions over 1 year. The therapy emphasized ways to reduce daily stress, time urgency, and hostility.

Over 8 years’ follow-up, the intervention group experienced 41% fewer first recurrent cardiovascular events and 45% fewer recurrent myocardial infarctions, compared with the control group. All-cause mortality did not differ significantly between groups.

The authors speculate that the CBT group may have reduced their behavioral and emotional reactivity, “which would lead to less psychophysiologic burden on the cardiovascular system.” They estimate that roughly 10 people would need to be treated in order to prevent one cardiovascular event.

Source:Archives of Internal Medicine

 

Early Cigarette Smoking Associated with Breast Cancer

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Young female patients who smoke may benefit from knowing that early smoking is associated with a modest increase in breast cancer risk, according to an Archives of Internal Medicine study.

Researchers analyzing updated data from the Nurses’ Health Study report that they have confirmed their 2002 finding of a slight elevation in breast cancer risk associated with smoking. During some 3 million person-years of follow-up between 1976 and 2006, women who smoked more than 25 cigarettes per day for more than 35 years and began smoking before age 18 had a hazard ratio for invasive breast cancer of 1.25, compared with never-smokers.

The effect was stronger when smoking began before the woman’s first birth and before menopause. Postmenopausal smoking was associated with a slightly decreased risk. There was no apparent increased risk from exposure to secondhand smoke.

Source:Archives of Internal Medicine