Seventeen years of American cutaneous leishmaniasis in a Southern Brazilian municipality

We reviewed the records of 151 patients diagnosed with American cutaneous leishmaniasis (ACL) from 1993 to 2009 in the municipality of Japura, Paraná, Brazil. Gender, age, occupation, place of residence, location of lesions, type and number of lesions were analyzed. The prevalence rate of ACL was 11.5/10,000 hab, of which 84.7% were male, 58.3% lived in rural area and 49.0% were farmers. The most frequent age group was between 30 to 39 years (26.6%). Skin lesions occurred in 92.7% of the patients with predominance in the lower limbs (23.9%) and 49.1% of the records did not include the number of lesions location due to incomplete filling. A single ulceration was present in 44.4%. Japurá is an endemic area for ACL, requiring public actions and preventive education.     

Characterisation of cannabinoid 1 receptor expression in the perikarya, and peripheral and spinal processes of primary sensory neurons

The cannabinoid 1 (CB1) receptor is expressed by a sub-population of primary sensory neurons. However, data on the neurochemical identity of the CB1 receptor-expressing cells, and CB1 receptor expression by the peripheral and central terminals of these neurons are inconsistent and limited. We characterised CB1 receptor expression in dorsal root ganglia (DRG) and spinal cord at the lumbar 4–5 level, as well as in the urinary bladder and glabrous skin of the hindpaw. About 1/3 of DRG neurons exhibited immunopositivity for the CB1 receptor, the majority of which showed positivity for the nociceptive markers calcitonin gene-related peptide (CGRP) or/and Griffonia (bandeiraea) simplicifolia IB4 isolectin-binding. Virtually all CB1 receptor-immunostained fibres showed immunopositivity for CGRP in the skin, while very few did in the urinary bladder. No CB1 receptor-immunopositive nerve fibres were IB4 positive in either peripheral tissue. Spinal laminae I and II-outer showed the highest density of CB1 receptor-immunopositive punctae, the majority of which showed positivity for CGRP or/and IB4 binding. These data indicate that a major sub-population of nociceptive primary sensory neurons expresses CB1 receptors that are transported to both peripheral and central terminals of these cells. Therefore, the present data suggest that manipulation of endogenous CB1 receptor agonist levels in these areas may significantly reduce nociceptive input into the spinal cord.     

Muscle strength and ankle mobility for the gait parameters in diabetic neuropathies

AimsTo evaluate the spatio-temporal variables of gait and the isometric muscle strength component of the ankle in patients with peripheral diabetic neuropathy. Also, verify the relationship between these variables and gait parameters.MethodsThis study involved 25 diabetic peripheral neuropathy (DPN) participants (62.4 ± 8.36 years) and 27 age-matched healthy control individuals (64.48 ± 6.21 years). The assessment of the spatio-temporal parameters of gait was performed using an electronic baropodometry treadmill. Prior to the collection data, each participant was instructed to walk on the treadmill in her/his habitual self-selected speed.ResultsDiabetic neuropathy group showed impairment of gait, with a smaller stride and length speed of the cycle, and increased duration of support time. Restricted dorsiflexion mobility and increased plantarflexion mobility were found, with a decrease in muscle strength of the dorsiflexors and plantiflexors. There was a significant relationship between plantiflexor muscle strength and the length and speed of the gait cycle. Also the muscle strengths of the plantiflexors and dorsiflexors, and the range of motion of dorsiflexion were predictors of gait performance.ConclusionsThe ankle, muscle strength and ankle mobility variables could explain changes in gait speed and range of motion in patients with DPN, allowing for the application of preventive strategies.     

Impact of aging on cardiac sympathetic innervation measured by <Superscript>123</Superscript>I-mIBG imaging in patients with systolic heart failure

Purpose

Sympathetic nervous system (SNS) hyperactivity is a salient characteristic of chronic heart failure (HF) and contributes to the progression of the disease. Iodine-123 meta-iodobenzylguanidine (¹²³I-mIBG) imaging has been successfully used to assess cardiac SNS activity in HF patients and to predict prognosis. Importantly, SNS hyperactivity characterizes also physiological ageing, and there is conflicting evidence on cardiac ¹²³I-mIBG uptake in healthy elderly subjects compared to adults. However, little data are available on the impact of ageing on cardiac sympathetic nerve activity assessed by ¹²³I-mIBG scintigraphy, in patients with HF.

Methods and results

We studied 180 HF patients (age?=?66.1?±?10.5 years [yrs]), left ventricular ejection fraction (LVEF?=?30.6?±?6.3 %) undergoing cardiac ¹²³I-mIBG imaging. Early and late heart to mediastinum (H/M) ratios and washout rate were calculated in all patients. Demographic, clinical, and echocardiographic data were also collected. Our study population consisted of 53 patients aged >75 years (age?=?77.7?±?4.0 year), 67 patients aged 62–72 years (age?=?67.9?±?3.2 years) and 60 patients aged ≤61 year (age?=?53.9?±?5.6 years). In elderly patients, both early and late H/M ratios were significantly lower compared to younger patients (p?<?0.05). By multivariate analysis, H/M ratios (both early and late) and washout rate were significantly correlated with LVEF and age.

Conclusions

Our data indicate that, in a population of HF patients, there is an independent age-related effect on cardiac SNS innervation assessed by ¹²³I-mIBG imaging. This finding suggests that cardiac ¹²³I-mIBG uptake in patients with HF might be affected by patient age.

     

Species-dependent serum interference in a sandwich ELISA for Apo2L/TRAIL

To support pre-clinical studies of Apo2L/TRAIL in rodents and non-human primates, a sandwich ELISA was developed using two mouse monoclonal anti-Apo2L/TRAIL antibodies. Mouse, rat, cynomolgus monkey, and chimpanzee serum at concentrations of > or =1% were found to interfere with accurate quantitation of Apo2L/TRAIL. Moreover, the characteristics of the serum interference for each species were different. In order to resolve the observed serum effect, studies were performed in which salts, detergents, and blocking proteins were added to the sample diluent, and optimized sample diluents that eliminated serum interference were developed for mouse, cynomolgus monkey, and chimpanzee serum. These buffers consisted of a base assay diluent (PBS/0.5% BSA/0.05% Tween-20/10 ppm ProClin 300) supplemented with: NaCl (mouse serum); NaCl, EDTA, CHAPS, bovine gamma globulin (BGG), and human IgG (cynomolgus monkey serum); and NaCl and EDTA (chimpanzee serum). Full characterization studies were performed for the "buffer" ELISA run in base assay diluent (intended for non-serum samples) as well as the assays optimized for mouse serum and cynomolgus monkey serum. Precision, accuracy, linearity, and specificity were found to be satisfactory. With the availability of a rabbit polyclonal antibody against Apo2L/TRAIL, a new pAb/mAb ELISA was developed. This assay was not only more sensitive by > or =6-fold, but it was also much less subject to serum interference.     

Increased Ca2+ sensitivity and protein expression of SERCA 2a in situations of chronic β3-adrenoceptor deficiency

This study investigated the influence of chronic β₃-adrenoceptor deficiency on myocardial function. Therefore, we investigated Ca²⁺-regulatory proteins, SERCA 2a activity, and myofibrillar and mitochondrial function in hearts of wild-type (WT, n=7) and β₃-adrenoceptor knockout mice (β₃-KNO, n=7). Morphometric heart analysis showed no difference between WT and β₃-KNO. No alterations were observed for the protein expression of the ryanodine receptor or phospholamban. However, in β₃-KNO mice, protein expression of SERCA 2a and phospholamban phosphorylation were significantly increased. These changes were accompanied by an increased SERCA 2a activity in β₃-KNO. Alterations in phospholamban phosphorylation were independent of alterations in β₁/β₂-adrenoceptor distribution and protein expression of G proteins in β₃-KNO. Measurement of myofibrillar Ca²⁺ sensitivity showed no difference in the Ca²⁺/force relation for WT and β₃-KNO. The same seems to hold true for mitochondrial function since the protein expressions of cytochrome c, uncoupling protein 3 and cytochrome c oxidase subunit IV were similar in WT and β₃-KNO. The conclusion is that depression of β₃-adrenergic stimulation may modulate the protein expression of SERCA 2a and phospholamban phosphorylation, thereby improving sarcoplasmic reticulum Ca²⁺ uptake. Thus, β₃-adrenergic depression may be a therapeutic aim in situations of impaired SERCA 2a activity, e.g. for the treatment of heart failure.     

GRK2 as a therapeutic target for heart failure

Introduction: G protein-coupled receptor (GPCR) kinase-2 (GRK2) is a regulator of GPCRs, in particular β-adrenergic receptors (ARs), and as demonstrated by decades of investigation, it has a pivotal role in the development and progression of cardiovascular disease, like heart failure (HF). Indeed elevated levels and activity of this kinase are able to promote the dysfunction of both cardiac and adrenal α- and β-ARs and to dysregulate other protective signaling pathway, such as sphingosine 1-phospate and insulin. Moreover, recent discoveries suggest that GRK2 can signal independently from GPCRs, in a ‘non-canonical’ manner, via interaction with non-GPCR molecule or via its mitochondrial localization.

Areas covered: Based on this premise, GRK2 inhibition or its genetic deletion has been tested in several disparate animal models of cardiovascular disease, showing to protect the heart from adverse remodeling and dysfunction.

Expert opinion: HF is one of the leading cause of death worldwide with enormous health care costs. For this reason, the identification of new therapeutic targets like GRK2 and strategies such as its inhibition represents a new hope in the fight against HF development and progression. Herein, we will update the readers about the ‘state-of-art’ of GRK2 inhibition as a potent therapeutic strategy in HF.     

New contribution to the study of ventricular remodeling and valve rings in dilated cardiomyopathy: anatomical and histological evaluation

Introduction

Idiopathic dilated cardiomyopathy causes great impact but many aspects of its pathophysiology remain unknown.

Objective

To evaluate anatomical and histological aspects of hearts with idiopathic dilated cardiomyopathy and compare them to a control group, evaluating the behavior of the perimeters of the atrioventricular rings and ventricles and to compare the percentage of collagen and elastic fibers of the atrioventricular rings.

Methods

Thirteen hearts with cardiomyopathy and 13 normal hearts were analysed. They were dissected keeping the ventricular mass and atrioventricular rings, with lamination of segments 20%, 50% and 80% of the distance between the atrioventricular groove and the ventricular apex. The sections were subjected to photo scanning, with measurement of perimeters. The atrioventricular rings were dissected and measured digitally to evaluate their perimeters, later being sent to the pathology laboratory, and stained by hematoxylin-eosin, picrosirius and oxidized resorcin fuccin.

Results

Regarding to ventricles, dilation occurs in all segments in the pathological group, and the right atrioventricular ring measurement was higher in idiopathic dilated cardiomyopathy group, with no difference in the left side. With respect to collagen, both sides had lower percentage of fibers in the pathological group. With respect to the elastic fibers, there was no difference between the groups.

Conclusion

There is a change in ventricular geometry in cardiomyopathy group. The left atrioventricular ring does not dilate, in spite of the fact that in both ventricles there is lowering of collagen.     

GABAB receptor phosphorylation regulates KCTD12-induced K current desensitization

GABA_B receptors assemble from GABA_B1 and GABA_B2 subunits. GABA_B2 additionally associates with auxiliary KCTD subunits (named after their K⁺ channel tetramerization-domain). GABA_B receptors couple to heterotrimeric G-proteins and activate inwardly-rectifying K⁺ channels through the βγ subunits released from the G-protein. Receptor-activated K⁺ currents desensitize in the sustained presence of agonist to avoid excessive effects on neuronal activity. Desensitization of K⁺ currents integrates distinct mechanistic underpinnings. GABA_B receptor activity reduces protein kinase-A activity, which reduces phosphorylation of serine-892 in GABA_B2 and promotes receptor degradation. This form of desensitization operates on the time scale of several minutes to hours. A faster form of desensitization is induced by the auxiliary subunit KCTD12, which interferes with channel activation by binding to the G-protein βγ subunits. Here we show that the two mechanisms of desensitization influence each other. Serine-892 phosphorylation in heterologous cells rearranges KCTD12 at the receptor and slows KCTD12-induced desensitization. Likewise, protein kinase-A activation in hippocampal neurons slows fast desensitization of GABA_B receptor-activated K⁺ currents while protein kinase-A inhibition accelerates fast desensitization. Protein kinase-A fails to regulate fast desensitization in KCTD12 knock-out mice or knock-in mice with a serine-892 to alanine mutation, thus demonstrating that serine-892 phosphorylation regulates KCTD12-induced desensitization in vivo. Fast current desensitization is accelerated in hippocampal neurons carrying the serine-892 to alanine mutation, showing that tonic serine-892 phosphorylation normally limits KCTD12-induced desensitization. Tonic serine-892 phosphorylation is in turn promoted by assembly of receptors with KCTD12. This cross-regulation of serine-892 phosphorylation and KCTD12 activity sharpens the response during repeated receptor activation.