Brood production increases when artificial heating is provided to colonies of stingless bees

Although stingless bees are capable of maintaining their nest temperature within certain limits, brood production of several species declines or even completely stops during periods of low ambient temperature. In the present study, we investigated whether the brood production of the meliponine species Nannotrigona testaceicornis can be artificially increased through heating the colonies during the cold season. For this, we monitored the rate of brood cell production of seven hives in intervals of 24 hours under two different experimental conditions: 1. without; and 2. with heating. Each treatment (first with and subsequently without heating) lasted for nine consecutive days. The ambient temperature (TA) during both experimental periods was very similar (TA(WITH) = 16.1 degrees C; TA(WITHOUT) = 16.3 degrees C). On average, the colonies built 3.6 brood cells per day without and 15.8 brood cells per day with artificial heating (Wilcoxon Rank Sum test: T = 10, Z = 4, P < 0.001). In both treatments, the rate of brood cell production increased with increasing environmental temperature (Spearman Rank Correlation: R(WITH) = 0.71, P = 0.02; R(WITHOUT) = 0.66, P = 0.05). We concluded that artificial heating during cold periods increased the brood cell production in N. testaceicornis Our results indicate that the use of heaters for stingless bee hives during periods of low ambient temperature may be helpful for stingless beekeeping.

Icelandic Control Really Is A-Movement: Reply to Bobaljik and Landau

This article discusses the challenges that Bobaljik and Landau (2009) pose to Boeckx and Hornstein`s (2006) movement-based analysis of control in Icelandic. We show in detail that contrary to what Bobaljik and Landau claim, the movement theory of control (with a modification to accommodate quirky Case, a specialty of Icelandic) makes the right empirical cuts regarding the issues they raise, namely, (a) the differences in Case agreement between control and raising constructions, (b) the different patterns of Case transmission (un)available, and (c) the fact that allegedly Case-marked PROs are phonetically null. We argue that rather than being problematic, the data bearing on these issues actually provide independent support to the movement theory of control.

Detrusor overactivity is associated with downregulation of large-conductance calcium- and voltage-activated potassium channel protein

Chang S, Gomes CM, Hypolite JA, Marx J, Alanzi J, Zderic SA, Malkowicz B, Wein AJ, Chacko S. Detrusor overactivity is associated with downregulation of large-conductance calcium-and voltage-activated potassium channel protein. Am J Physiol Renal Physiol 298: F1416-F1423, 2010. First published April 14, 2010; doi: 10.1152/ajprenal.00595.2009.-Large-conductance voltage-and calcium-activated potassium (BK) channels have been shown to play a role in detrusor overactivity (DO). The goal of this study was to determine whether bladder outlet obstructioninduced DO is associated with downregulation of BK channels and whether BK channels affect myosin light chain 20 (MLC(20)) phosphorylation in detrusor smooth muscle (DSM). Partial bladder outlet obstruction (PBOO) was surgically induced in male New Zealand White rabbits. The rabbit PBOO model shows decreased voided volumes and increased voiding frequency. DSM from PBOO rabbits also show enhanced spontaneous contractions compared with control. Both BK channel alpha- and beta-subunits were significantly decreased in DSM from PBOO rabbits. Immunostaining shows BK beta mainly expressed in DSM, and its expression is much less in PBOO DSM compared with control DSM. Furthermore, a translational study was performed to see whether the finding discovered in the animal model can be translated to human patients. The urodynamic study demonstrates several overactive DSM contractions during the urine-filling stage in benign prostatic hyperplasia (BPH) patients with DO, while DSM is very quiet in BPH patients without DO. DSM biopsies revealed significantly less BK channel expression at both mRNA and protein levels. The degree of downregulation of the BK beta-subunit was greater than that of the BK alpha-subunit, and the downregulation of BK was only associated with DO, not BPH. Finally, the small interference (si) RNA-mediated downregulation of the BK beta-subunit was employed to study the effect of BK depletion on MLC(20) phosphorylation. siRNA-mediated BK channel reduction was associated with an increased MLC(20) phosphorylation level in cultured DSM cells. In summary, PBOO-induced DO is associated with downregulation of BK channel expression in the rabbit model, and this finding can be translated to human BPH patients with DO. Furthermore, downregulation of the BK channel may contribute to DO by increasing the basal level of MLC(20) phosphorylation.

Elevated expression of MeCP2 in cardiac and skeletal tissues is detrimental for normal development

MeCP2 plays a critical role in interpreting epigenetic signatures that command chromatin conformation and regulation of gene transcription. In spite of MeCP2`s ubiquitous expression, its functions have always been considered in the context of brain physiology. In this study, we demonstrate that alterations of the normal pattern of expression of MeCP2 in cardiac and skeletal tissues are detrimental for normal development. Overexpression of MeCP2 in the mouse heart leads to embryonic lethality with cardiac septum hypertrophy and dysregulated expression of MeCP2 in skeletal tissue produces severe malformations. We further show that MeCP2`s expression in the heart is developmentally regulated; further suggesting that it plays a key role in regulating transcriptional programs in non-neural tissues.

Obstructive Sleep Apnea Is Common and Independently Associated With Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is associated with arrhythmias and cardiovascular death. Left atrial enlargement and atrial fibrillation (AF) are considered markers for death due to heart failure in patients with HCM. Obstructive sleep apnea (OSA) is independently associated with heart remodeling and arrhythmias in other populations. We hypothesized that OSA is common and is associated with heart remodeling and AF in patients with HCM. Methods: We evaluated 80 consecutive stable patients with a confirmed diagnosis of HCM by sleep questionnaire, blood tests, echocardiography, and sleep study (overnight respiratory monitoring). Results: OSA (apnea-hypopnea index [AHI] > 15 events/h) was present in 32 patients (40%). Patients with OSA were significantly older (56 [41-64] vs 38.5 [30-53] years, P < .001) and presented higher BMI (28.2 +/- 3.5 vs 25.2 +/- 5.2 kg/m(2), P < .01) and increased left atrial diameter (45 [42-52.8] vs 41 [39-47] mm, P = .01) and aorta diameter (34 [30-37] vs 29 [28-32] mm, P < .001), compared with patients without OSA. Stepwise multiple linear regression showed that the AHI (P = .05) and BMI (P = .06) were associated with left atrial diameter. The AHI was the only variable associated with aorta diameter (P = .01). AF was present in 31% vs 6% of patients with and without OSA, respectively (P < .01). OSA (P = .03) and left atrial diameter (P = .03) were the only factors independently associated with AF. Conclusions: OSA is highly prevalent in patients with HCM and it is associated with left atrial and aortic enlargement. OSA is independently associated with AF, a risk factor for cardiovascular death in this population. CHEST 2010; 137(5):1078-1084

Coronary Calcification Is Associated With Lower Bone Formation Rate in CKD Patients Not Yet in Dialysis Treatment

Vascular calcification is a strong prognostic marker of mortality in hemodialysis patients and has been associated with bone metabolism disorders in this population. In earlier stages of chronic kidney disease (CKD), vascular calcification also has been documented. This study evaluated the association between coronary artery calcification (CAC) and bone histomorphometric parameters in CKD predialysis patients assessed by multislice coronary tomography and by undecalcified bone biopsy. CAC was detected in 33 (66%) patients, and their median calcium score was 89.7 (0.4-2299.3 AU). The most frequent bone histologic alterations observed included low trabecular bone volume, increased eroded and osteoclast surfaces, and low bone-formation rate (BFR/BS). Multiple logistic regression analysis, adjusted for age, sex, and diabetes, showed that BFR/BS was independently associated with the presence of coronary calcification [p=.009; odd ratio (OR) = 0.15; 95% confidence interval (Cl) 0.036-0.619] This study showed a high prevalence of CAC in asymptomatic predialysis CKD patients. Also, there was an independent association of low bone formation and CAC in this population. In conclusion, our results provide evidence that low bone-formation rate constitutes another nontraditional risk factor for cardiovascular disease in CKD patients. 2010 American Society for Bone and Mineral Research.

PHRENIC NERVE TRANSFER IN THE RESTORATION OF ELBOW FLEXION IN BRACHIAL PLEXUS AVULSION INJURIES: HOW EFFECTIVE AND SAFE IS IT?

OBJECTIVE: Phrenic nerve transfer has been used for treating lesions of the brachial plexus since 1970. Although, today, surgeons are more experienced with the technique, there are still widespread concerns about its effects on pulmonary function. This study was undertaken to evaluate the effectiveness and safety of this procedure. METHODS: Fourteen patients with complete palsy of the upper limb were submitted to phrenic nerve transfer as part of a strategy for surgical reconstruction of their plexuses. Two patients were lost to follow-up, and 2 patients were followed for less than 2 years. Of the remaining 10 patients, 9 (90%) were male. The lesions affected both sides equally. The mean age of the patients was 24.8 years (range, 14-43 years), and the mean interval from injury to surgery was 6 months (range, 3-9 months). The phrenic nerve was always transferred to the musculocutaneous nerve, and a nerve graft (mean length, 8 cm; range, 4.5-12 cm) was necessary in all cases. RESULTS: There was no major complication related to the surgery. Seven patients (70%) recovered functional level biceps strength (Medical Research Council grade >= 3). All of the patients exhibited a transient decrease in pulmonary function tests, but without clinical respiratory problems. CONCLUSION: On the basis of our small series and data from the literature, we conclude that phrenic nerve transfer in well-selected patients is a safe and effective procedure for recovering biceps function.

Is Coronary Artery Calcification Associated with Vertebral Bone Density in Nondialyzed Chronic Kidney Disease Patients?

Background and objectives Low bone mineral density and coronary artery calcification (CAC) are highly prevalent among chronic kidney disease (CKD) patients, and both conditions are strongly associated with higher mortality. The study presented here aimed to investigate whether reduced vertebral bone density (VBD) was associated with the presence of CAC in the earlier stages of CKD. Design, setting, participants, & measurements Seventy-two nondialyzed CKD patients (age 52 +/- 11.7 years, 70% male, 42% diabetics, creatinine clearance 40.4 +/- 18.2 ml/min per 1.73 m(2)) were studied. VBD and CAC were quantified by computed tomography. Results CAC > 10 Agatston units (AU) was observed in 50% of the patients (median 120 AU [interquartile range 32 to 584 AU]), and a calcification score >= 400 AU was found in 19% (736 [527 to 1012] AU). VBD (190 +/- 52 Hounsfield units) correlated inversely with age (r = -0.41, P < 0.001) and calcium score (r = -0.31, P = 0.01), and no correlation was found with gender, creatinine clearance, proteinuria, lipid profile, mineral parameters, body mass index, and diabetes. Patients in the lowest tertile of VBD had expressively increased calcium score in comparison to the middle and highest tertile groups. In the multiple logistic regression analysis adjusting for confounding variables, low VBD was independently associated with the presence of CAC. Conclusions Low VBD was associated with CAC in nondialyzed CKD patients. The authors suggest that low VBD might constitute another nontraditional risk factor for cardiovascular disease in CKD. Clin J Am Soc Nephrol 6: 1456-1462, 2011. doi: 10.2215/CJN.10061110

Bile duct ligation in neonatal rats: Is it a valid experimental model for biliary atresia studies?

BA is the most important disease requiring liver transplantation in children. Common BDL in rats is a classic experimental model to study biliary obstruction. The response of the neonatal animal to BDL has yet to be completely understood and few reports have focused on the behavioral differences of the liver between neonatal and adult animals. Ninety newborn Wistar rats aged six days, weighing 8.0-13.9 g, and 90 adult Wistar rats weighing 199.7-357.0 g, were submitted to BDL. After surgery, they were randomly divided and killed on the 3rd, 5th, 7th, 14th, 21st and 28th day post-BDL. Hepatic biopsies were obtained and the following were measured: (i) semiquantification of the bile ductule proliferation and inflammatory infiltrate by HE stain, (ii) quanti. cation of portal and periportal fibrosis with the Sirius-red stain. Although the initial response of ductule proliferation and inflammatory infiltrate were less intense in the newborn animal, the portal and periportal fibrosis were higher when compared with adult animals (p < 0.0491). These findings may contribute to the understanding of the pathophysiology of BA.

Antinociception induced by epidural motor cortex stimulation in naive conscious rats is mediated by the opioid system

Epidural motor cortex stimulation (MCS) has been used for treating patients with neuropathic pain resistant to other therapeutic approaches. Experimental evidence suggests that the motor cortex is also involved in the modulation of normal nociceptive response, but the underlying mechanisms of pain control have not been clarified yet. The aim of this study was to investigate the effects of epidural electrical MCS on the nociceptive threshold of naive rats. Electrodes were placed on epidural motor cortex, over the hind paw area, according to the functional mapping accomplished in this study. Nociceptive threshold and general activity were evaluated under 15-min electrical stimulating sessions. When rats were evaluated by the paw pressure test, MCS induced selective antinociception in the paw contralateral to the stimulated cortex, but no changes were noticed in the ipsilateral paw. When the nociceptive test was repeated 15 min after cessation of electrical stimulation, the nociceptive threshold returned to basal levels. On the other hand, no changes in the nociceptive threshold were observed in rats evaluated by the tail-flick test. Additionally, no behavioral or motor impairment were noticed in the course of stimulation session at the open-field test. Stimulation of posterior parietal or somatosensory cortices did not elicit any changes in the general activity or nociceptive response. Opioid receptors blockade by naloxone abolished the increase in nociceptive threshold induced by MCS. Data shown herein demonstrate that epidural electrical MCS elicits a substantial and selective antinociceptive effect, which is mediated by opioids. (C) 2008 Elsevier B.V. All rights reserved.

Urine Volume in Acute Kidney Injury: How Much Is Enough?

Eight hundred and seventy-nine patients with acute kidney injury were retrospectively studied over year and eleven months for evaluation of urine volume as a risk factor for death. They were divided into five groups, according to the 24 h urine volume (UV): anuric (UV <= 50 mL/24 h, group 1), oliguric (UV > 50 mL/24 h and < 400 mL/24 h, group 2), and non-oliguric (UV >= 400 mL/24 h). Nonoliguric group was subdivided in three subgroups: UV > 400 mL/24 h and <= 1000 mL/24 h (group 3, reference group), UV > 1000 mL/24 h and <= 2000 mL/24 h (group 4), and UV > 2000 mL/24 h (group 5). Linear tendency test (Mantel extension) pointed out a significant increase in mortality with UV decrease (p < 0.001), confirmed by multivariate analysis. Anuric and oliguric patients had increased risk of respectively 95% and 76% times for death compared to controls (p < 0.05). Patients from groups 4 and 5 presented a reduced risk for death of 50% and 70%, respectively, p = 0.004 and p = 0.001. In conclusion, urine volume was a strong independent factor for mortality in this cohort of AKI patients.

Anxiety Disorders and Rheumatic Fever: Is There an Association?

Introduction: Findings suggest that obsessive-compulsi e disorder (OCD) and related disorders, referred to as obsessive-compulsive spectrum disorders (OCSDs), are more common in patients with rheumatic fever (RF). Objectives: To determine whether RF or Sydenham`s chorea increases the probability of anxiety disorders in the relatives of individuals with RF with and without SC. Methods: This was a case-Control family study in which 98 probands and 389 first-degree relatives (FDRs) were assessed using structured psychiatric interviews. A Poisson regression model was used to determine whether the presence of any disorder in one family member influences the rate of disorders in the remaining family members. Results: Generalized anxiety disorder (GAD) occurred more frequently in the FDRs of RF probands than in those of control probands (P=.018). The presence of RF,GAD, or separation anxiety disorder in one family member significantly increased the chance of OCSDs in another member of the family.

RANKL is a mediator of bone resorption in idiopathic hypercalciuria

Background and objectives: This study aimed to determine the expression of osteoprotegerin, receptor activator of nuclear factor kappa B ligand, interleukin-la, transforming growth factor-beta, and basic fibroblast growth factor in stone-forming patients with idiopathic hypercalciuria. Design, setting, participants, & measurements: Immunohistochemical analysis was performed in undecalcified bone samples previously obtained from 36 transiliac bone biopsies of patients who had idiopathic hypercalciuria and whose histomorphometry had shown lower bone volume, increased bone resorption, and prolonged mineralization lag time. Results: Bone expression of receptor activator of nuclear factor kappa B ligand and osteoprotegerin was significantly higher in patients with idiopathic hypercalciuria versus control subjects. Transforming growth factor-beta immunostaining was lower in patients with idiopathic hypercalciuria than in control subjects and correlated directly with mineralization surface. Interleukin-la and basic fibroblast growth factor staining did not differ between groups. Receptor activator of nuclear factor kappa B ligand bone expression was significantly higher in patients who had idiopathic hypercalciuria and exhibited higher versus normal bone resorption. Conclusion: A higher expression of receptor activator of nuclear factor kappa B ligand in bone tissue suggests that increased bone resorption in patients with idiopathic hypercalciuria is mediated by receptor activator of nuclear factor kappa B ligand. Osteoprotegerin bone expression might have been secondarily increased in an attempt to counteract the actions of receptor activator of nuclear factor kappa B ligand. The low bone expression of transforming growth factor-beta could contribute to the delayed mineralization found in such patients.

The common p450 oxidoreductase variant A503V is not a modifier gene for 21-hydroxylase deficiency

Context: 21-hydroxylase deficiency (21OHD) is a common genetic disorder caused by mutations in the CYP21A2 gene, which encodes the adrenal 21-hydroxylase, microsomal P450c21. CYP21A2 gene mutations generally correlate well with impaired P450c21 enzymatic activity and the clinical findings in 21OHD, but occasional discrepancies between genotype and phenotype suggest the effects of modifier genes. Mutations in P450 oxidoreductase (POR), the protein that transfers electrons from reduced nicotinamide adenine dinucleotide phosphate to all microsomal P450s, can ameliorate the 21OHD phenotype and, therefore, could be a modifier gene. Objectives: We sought to identify POR variants in patients with 21OHD having discordant phenotype and genotype, and to evaluate their effect on 21-hydroxylase activity. Patients and Methods: We determined the CYP21A2 genotypes of 313 Brazilian patients with 21OHD and correlated the genotype and phenotype. The POR gene was sequenced in 17 patients with discordant genotype and phenotype. Wild-type and A503V POR, and P450c21 were expressed in bacteria and reconstituted in vitro. Activities were assayed by conversion of [C-14] progesterone to deoxycorticosterone and [H-3]17-hydroxyprogesterone to 11-deoxycortisol, and assessed by thin layer chromatography and phosphorimaging. Results: The A503V POR variant was found in 10 of 30 alleles, the same ratio as in the normal population. There were no significant differences in Michaelis constant, maximum velocity and maximum velocity/Michaelis constant of 21-hydroxylase activity supported by wild-type and A503V POR. Conclusion: The only POR missense polymorphism found in atypical 21OHD patients was A503V. Although A503V reduces P450c17 enzymatic activity, it does not influence P450c21 activity, indicating that POR A503V does not modify the 21OHD phenotype.

Is facial pattern a predisposing factor for otitis media with effusion in children?

Abnormalities in craniofacial morphology are associated with Eustachian tube dysfunction and otitis media with effusion (OME). Aim: to evaluate the relationship between facial pattern and craniofacial growth direction, and OME in children with enlarged tonsils and adenoids (ETA). Methods: Clinical prospective survey in 79 children (41 male and 38 female), ranging from 4 to 10 years of age, with tonsil and adenoid enlargement (Brodsky`s grades III and IV). Forty children presented with OME (study group) and 39 did not (control group). Cephalometric analysis was used to determine the facial pattern. Results: There was no correlation observed between facial pattern and OME (c 2 = 0.25 p = 0.88). Facial Axis was larger in the OME group (F(1.75) = 3.68 p = 0.05) and the Lower Anterior Facial height was smaller (F(1. 75) = 3.99 p = 0.05) in children with otitis media with effusion. Conclusions: There was no correlation between OME and facial pattern in children with ETA although a more horizontal facial growth direction, and a smaller lower anterior facial height was observed consistently among subjects in this group. This suggests that abnormal positioning of the eustachian tube influences the development of OME in children with ETA.