Paracrine signalling by cardiac calcitonin controls atrial fibrogenesis and arrhythmia

Atrial fibrillation, the most common cardiac arrhythmia, is an important contributor to mortality and morbidity, and particularly to the risk of stroke in humans¹. Atrial-tissue fibrosis is a central pathophysiological feature of atrial fibrillation that also hampers its treatment; the underlying molecular mechanisms are poorly understood and warrant investigation given the inadequacy of present therapies². Here we show that calcitonin, a hormone product of the thyroid gland involved in bone metabolism³, is also produced by atrial cardiomyocytes in substantial quantities and acts as a paracrine signal that affects neighbouring collagen-producing fibroblasts to control their proliferation and secretion of extracellular matrix proteins. Global disruption of calcitonin receptor signalling in mice causes atrial fibrosis and increases susceptibility to atrial fibrillation. In mice in which liver kinase B1 is knocked down specifically in the atria, atrial-specific knockdown of calcitonin promotes atrial fibrosis and increases and prolongs spontaneous episodes of atrial fibrillation, whereas atrial-specific overexpression of calcitonin prevents both atrial fibrosis and fibrillation. Human patients with persistent atrial fibrillation show sixfold lower levels of myocardial calcitonin compared to control individuals with normal heart rhythm, with loss of calcitonin receptors in the fibroblast membrane. Although transcriptome analysis of human atrial fibroblasts reveals little change after exposure to calcitonin, proteomic analysis shows extensive alterations in extracellular matrix proteins and pathways related to fibrogenesis, infection and immune responses, and transcriptional regulation. Strategies to restore disrupted myocardial calcitonin signalling thus may offer therapeutic avenues for patients with atrial fibrillation.

Detecting human coronary inflammation by imaging perivascular fat

Early detection of vascular inflammation would allow deployment of targeted strategies for the prevention or treatment of multiple disease states. Because vascular inflammation is not detectable with commonly used imaging modalities, we hypothesized that phenotypic changes in perivascular adipose tissue (PVAT) induced by vascular inflammation could be quantified using a new computerized tomography (CT) angiography methodology. We show that inflamed human vessels release cytokines that prevent lipid accumulation in PVAT-derived preadipocytes in vitro, ex vivo, and in vivo. We developed a three-dimensional PVAT analysis method and studied CT images of human adipose tissue explants from 453 patients undergoing cardiac surgery, relating the ex vivo images with in vivo CT scan information on the biology of the explants. We developed an imaging metric, the CT fat attenuation index (FAI), that describes adipocyte lipid content and size. The FAI has excellent sensitivity and specificity for detecting tissue inflammation as assessed by tissue uptake of 18F-fluorodeoxyglucose in positron emission tomography. In a validation cohort of 273 subjects, the FAI gradient around human coronary arteries identified early subclinical coronary artery disease in vivo, as well as detected dynamic changes of PVAT in response to variations of vascular inflammation, and inflamed, vulnerable atherosclerotic plaques during acute coronary syndromes. Our study revealed that human vessels exert paracrine effects on the surrounding PVAT, affecting local intracellular lipid accumulation in preadipocytes, which can be monitored using a CT imaging approach. This methodology can be implemented in clinical practice to noninvasively detect plaque instability in the human coronary vasculature.

Alternative Splicing of IGF1 Gene as a Potential Factor in the Pathogenesis of Peyronie's Disease

BACKGROUND/AIM

Peyronie's disease (PD) is a fibrotic entity for which the pathogenetic mechanism remains unclear and if resulting in severe deformity, its treatment is only surgical. In this study we investigated the possible role of insulin-like growth factor 1 (IGF1) expression in the pathogenesis of PD.

MATERIALS AND METHODS

Tissue samples were obtained from plaques of 24 patients with PD. The expression of IGF1 isoforms was investigated using quantitative real-time polymerase chain reaction and immunofluorescence.

RESULTS

All IGF1 isoform gene expression (Ea, Eb and Ec) were found significantly decreased in the affected tunica albuginea, compared to normal tunica albuginea, with Ec showing the greatest decrease. Staining of tissue sections with an antibody against IGF1Ec confirmed greater expression of IGF1Ec isoform in normal tunica albuginea.

CONCLUSION

The expression of all IGF1 alternative spliced isoforms is decreased in patients with PD, suggestive of its possible participation in the pathophysiology of PD.

Oncogenic Role of the Ec Peptide of the IGF-1Ec Isoform in Prostate Cancer

IGF-1 is one of the key molecules in cancer biology; however, little is known about the role of the preferential expression of the premature IGF-1 isoforms in prostate cancer. We have examined the role of the cleaved COO- terminal peptide (PEc) of the third IGF-1 isoform, IGF-1Ec, in prostate cancer. Our evidence suggests that endogenously produced PEc induces cellular proliferation in the human prostate cancer cells (PC-3) in vitro and in vivo, by activating the ERK1/2 pathway in an autocrine/paracrine manner. PEc overexpressing cells and tumors presented evidence of epithelial to mesenchymal transition, whereas the orthotopic injection of PEc-overexpressing, normal prostate epithelium cells (HPrEC) in SCID mice was associated with increased metastatic rate. In humans, the IGF-1Ec expression was detected in prostate cancer biopsies, where its expression correlates with tumor stage. Our data describes the action of PEc in prostate cancer biology and defines its potential role in tumor growth, progression and metastasis.

Reciprocal Effects of Systemic Inflammation and Brain Natriuretic Peptide on Adiponectin Biosynthesis in Adipose Tissue of Patients With Ischemic Heart Disease

Objective—

To explore the role of systemic inflammation in the regulation of adiponectin levels in patients with ischemic heart disease.

Approach and Results—

In a cross-sectional study of 575 subjects, serum adiponectin was compared between healthy subjects, patients with coronary artery disease with no/mild/severe heart failure (HF), and patients with nonischemic HF. Adiponectin expression and release from femoral, subcutaneous and thoracic adipose tissue was determined in 258 additional patients with coronary artery bypass grafting. Responsiveness of the various human adipose tissue depots to interleukin-6, tumor necrosis factor-α, and brain natriuretic peptide (BNP) was examined by using ex vivo models of human fat. The effects of inducible low-grade inflammation were tested by using the model of Salmonella typhi vaccine-induced inflammation in healthy individuals. In the cross-sectional study, HF strikingly increased adiponectin levels. Plasma BNP was the strongest predictor of circulating adiponectin and its release from all adipose tissue depots in patients with coronary artery bypass grafting, even in the absence of HF. Femoral AT was the depot with the least macrophages infiltration and the largest adipocyte cell size and the only responsive to systemic and ex vivo proinflammatory stimulation (effect reversible by BNP). Low-grade inflammation reduced circulating adiponectin levels, while circulating BNP remained unchanged.

Conclusions—

This study demonstrates the regional variability in the responsiveness of human adipose tissue to systemic inflammation and suggests that BNP (not systemic inflammation) is the main driver of circulating adiponectin in patients with advanced atherosclerosis even in the absence of HF. Any interpretation of circulating adiponectin as a biomarker should take into account the underlying disease state, background inflammation, and BNP levels.

Cortical potentials as predictors of outcomes with adult cochlear implant recipients - preliminary findings

A proportion of adult cochlear implant recipients report an inability to use the signal from their cochlear implant effectively at varying post-operative intervals following cochlear implantation. Some of these recipients report deterioration in their ability to use the implant signal and do not benefit from map optimization. Others never attain the level of outcome that they had expected. Speech perception, functional listening in certain circumstances and EABR may demonstrate high performance with the cochlear implant. However recipients report extreme difficulty in noise and distortion of the signal with the cochlear implant. Commonly, environmental sounds overshadow speech. Cortical evoked potentials were measured in a group of recipients who had been reporting such difficulties. They revealed potential processing abnormalities at the level of the cortex in some of these cases. This paper will review the five result profiles that were obtained based on pre-operative, intra-operative and post-operative outcomes. It will begin to explore the value of predictive factors that may indicate the difficulties these recipients would experience post-operatively. Further, management strategies to evaluate and assist in optimizing performance will be addressed.

Protracted acute stress reaction following an earthquake

OBJECTIVE

To verify the official criteria of ICD-10 diagnosis of acute stress reaction (ASR) among earthquake victims.

METHOD

Data on psychosocial variables and the diagnosis of ASR were collected from 91 subjects.

RESULTS

The diagnosis of ASR was made in 70% of the sample. However, the restrictive duration criterion (i.e. symptoms not exceeding the first 48 h) was fulfilled only in 10%; in the remaining 60% the symptoms lasted for about another week. Thus, 60% of the sample constituted a group with protracted ASR (PASR) and 40% a group without it (n-PASR). Medical history was more frequent among PASR than n-PASR; PASR showed higher anxiety levels (both pre- and post-disaster) than n-PASR; finally, the persistence of ASR related positively to the fear of death at the time of the earthquake and pre-disaster anxiety levels.

CONCLUSION

As in the vast majority of earthquake victims the ASR is protracted beyond 48 h, a revision of ICD-10 guidelines should be considered.

Should children who use cochlear implants wear hearing aids in the opposite ear?

OBJECTIVE

The aim of this study was to investigate 1) whether a hearing aid needs to be adjusted differently depending on whether a child wears a cochlear implant or another hearing aid in the contralateral ear; 2) whether the use of a hearing aid and a cochlear implant in opposite ears leads to binaural interference; and 3) whether the use of a hearing aid and a cochlear implant in opposite ears leads to binaural benefits in speech perception, localization, and communicative functioning in real life.

DESIGN

Sixteen children participated in this study. All children used a Nucleus 22 or Nucleus 24 cochlear implant system programmed with the SPEAK strategy in one ear. The hearing aid amplification requirements in the nonimplanted ear of these children were determined using two procedures. A paired comparison technique was used to identify the frequency response that was best for speech intelligibility in quiet, and a loudness balancing technique was used to match the loudness of speech in the ear with a hearing aid to that with a cochlear implant. Eleven of the 16 children participated in the investigation of binaural effects. Performance in speech perception, localization, and communicative functioning was assessed under four aided conditions: cochlear implant with hearing aid as worn, cochlear implant alone, hearing aid alone, and cochlear implant with hearing aid adjusted according to individual requirements.

RESULTS

Fifteen of the 16 children whose amplification requirements were determined preferred a hearing aid frequency response that was within +/-6 dB/octave of the NAL-RP prescription. On average, the children required 6 dB more gain than prescribed to balance the loudness of the implanted ear for a speech signal presented at 65 dB SPL. For all 11 children whose performance was evaluated for investigating binaural effects, there was no indication of significantly poorer performance under bilaterally aided conditions compared with unilaterally aided conditions. On average, there were significant benefits in speech perception, localization, and aural/oral function when the children used cochlear implants with adjusted hearing aids than when they used cochlear implants alone. All individuals showed benefits in at least one of the measures.

CONCLUSIONS

Hearing aids for children who also use cochlear implants can be selected using the NAL-RP prescription. Adjustment of hearing aid gain to match loudness in the implanted ear can facilitate integration of signals from both ears, leading to better speech perception. Given that there are binaural advantages from using cochlear implants with hearing aids in opposite ears, clinicians should advise parents and other professionals about these potential advantages, and facilitate bilateral amplification by adjusting hearing aids after stable cochlear implant MAPs are established.

Melatonin response to clonidine administration in depression: indication of presynaptic alpha2-adrenoceptor dysfunction

BACKGROUND

The aim of this study was to investigate alpha2-adrenoceptor sensitivity in depression, by using melatonin response to clonidine administration as an index of alpha2-adrenoceptor functioning.

METHOD

35 depressed subjects and 41 healthy controls were assessed for overnight urinary melatonin pre- and post-administration of oral clonidine.

RESULTS

Administration of clonidine significantly reduced melatonin concentrations in depressed patients but not in control subjects.

LIMITATION

A single oral dose (0.15 mg) of clonidine was administered.

CONCLUSIONS

Further indication is provided for presynaptic alpha2-adrenoceptor dysfunction in depression with the application of an alternative pharmacological challenge method.

Relationships among speech perception, production, language, hearing loss, and age in children with impaired hearing

Eighty-seven primary-school children with impaired hearing were evaluated using speech perception, production, and language measures over a 3-year period. Forty-seven children with a mean unaided pure-tone-average hearing loss of 106 dB HL used a 22-electrode cochlear implant, and 40 with a mean unaided pure-tone-average hearing loss of 78 dB HL were fitted with hearing aids. All children were enrolled in oral/aural habilitation programs, and most attended integrated classes with normally hearing children for part of the time at school. Multiple linear regression was used to describe the relationships among the speech perception, production, and language measures, and the trends over time. Little difference in the level of performance and trends was found for the two groups of children, so the perceptual effect of the implant is equivalent, on average, to an improvement of about 28 dB in hearing thresholds. Scores on the Peabody Picture Vocabulary Test (PPVT) and the Clinical Evaluation of Language Fundamentals showed an upward trend at about 60% of the rate for normally hearing children. Rates of improvement for individual children were not correlated significantly with degree of hearing loss. The children showed a wide scatter about the average speech production score of 40% of words correctly produced in spontaneous conversations, with no significant upward trend with age. Scores on the open-set Consonant-Nucleus-Consonant (CNC) monosyllabic word test and the Bench-Kowal-Bamford (BKB) sentence test were strongly related to language level (as measured by an equivalent age on the PPVT) and speech production scores for both auditory-visual and auditory test conditions. After allowing for differences in language, speech perception scores in the auditory test condition showed a slight downward trend over time, which is consistent with the known biological effects of hearing loss on the auditory periphery and brainstem. Speech perception scores in the auditory condition also decreased significantly by about 5% for every 10 dB of hearing loss in the hearing aid group. The regression analysis model allows separation of the effects of language, speech production, and hearing levels on speech perception scores so that the effects of habilitation and training in these areas can be observed and/or predicted. The model suggests that most of the children in the study will reach a level of over 90% sentence recognition in the auditory-visual condition when their language becomes equivalent to that of a normally hearing 7-year-old, but they will enter secondary school at age 12 with an average language delay of about 4 or 5 years unless they receive concentrated and effective language training.

Performance after cochlear implantation: a comparison of children deafened by meningitis and congenitally deaf children

The speech perception and speech production performance following cochlear implantation of congenitally deaf children and children deafened by meningitis were analysed. Three groups consisting of 70 congenitally deaf children, 22 children deafened by meningitis before two years of age and 14 children deafened by meningitis after two years of age were compared. The group deafened by meningitis after two years of age demonstrated significantly better speech perception than the other two groups. Their speech production appeared better but did not achieve statistical significance compared with the other two groups. There was no significant difference in either speech perception or speech production between the congenitally deaf group and the group deafened by meningitis before two years of age.

Dependence on zolpidem: a case report

We report the case of a patient with a history of zolpidem dependence. The patient, after a stressful life event, started using zolpidem. She rapidly developed tolerance and dependence, taking 50-100 mg, and sometimes up to 300 mg, of zolpidem daily. Also, our patient suffered episodes of altered consciousness, accompanied by visual hallucinations.

Aggression among psychiatric inpatients in Greece

We studied, during 5 consecutive days, the prevalence, types and demographic, historical and clinical correlates of overt aggression in a population of 136 acute and chronic inpatients with mainly a diagnosis of psychotic disorder. Almost one fourth of them exhibited some sort of aggressive behavior. Verbal aggression was by far the most frequent type followed-in decreasing order-by physical aggression, aggression against property and self-aggression. Past threats of violence and attacks on others as well as concurrent motor excitement, agitation, low tolerance of frustration, difficulty in delaying gratification, depressive feelings, anger, hostility, affective lability and antisocial behavior differed significantly across the aggressive and the nonaggressive groups. The best short-term clinical predictors of aggression were different for each type, anger being their sole common predictor, and accounted for various proportions of the corresponding variances ranging from only 13.3% for self-aggression to 39.2% for verbal aggression.