Obstructive sleep apnea: Beyond the dogma of obesity!

Obstructive sleep apnea (OSA) has long been studied in patients with obesity and type 2 diabetes mellitus (T2DM), due to the fact that both disorders are commonly associated with an increased body mass index (BMI). However, a link between OSA and non-obese diabetic patients is still not very elaborated, nor heavily explored. In this review, we elucidate some proposed mechanisms for the link between OSA and diabetic patients both with and beyond obesity, shedding the light on the latter case. One such mechanism is oxidative stress, a phenomenon of reactive oxygen species (ROS) imbalance seen in both of the previously mentioned disorders. A plausible explanation for the OSA-induced ROS production is the repeating episodes of hypoxia and reperfusion and their effect on the mitochondrial electron transport chain. This paper explores the literature regarding ROS imbalance as the possible missing link between OSA and Diabetes Mellitus beyond obesity, while still mentioning other possible proposed mechanisms such as a dysregulated autonomic nervous system (ANS), as well as mechanical and craniofacial abnormalities. This paper also suggests a link between OSA and diabetic complications, while exploring the clinical progress made in treating the former disorder with anti-oxidant and hypo-glycemic drugs. If further investigated, these findings could help identify novel therapeutic interventions for the treatment of OSA and Diabetic patients.

Structural and signaling proteins in the Z-disk and their role in cardiomyopathies

The sarcomere is the smallest functional unit of muscle contraction. It is delineated by a protein-rich structure known as the Z-disk, alternating with M-bands. The Z-disk anchors the actin-rich thin filaments and plays a crucial role in maintaining the mechanical stability of the cardiac muscle. A multitude of proteins interact with each other at the Z-disk and they regulate the mechanical properties of the thin filaments. Over the past 2 decades, the role of the Z-disk in cardiac muscle contraction has been assessed widely, however, the impact of genetic variants in Z-disk proteins has still not been fully elucidated. This review discusses the various Z-disk proteins (alpha-actinin, filamin C, titin, muscle LIM protein, telethonin, myopalladin, nebulette, and nexilin) and Z-disk-associated proteins (desmin, and obscurin) and their role in cardiac structural stability and intracellular signaling. This review further explores how genetic variants of Z-disk proteins are linked to inherited cardiac conditions termed cardiomyopathies.

Conserved roles of Osiris genes in insect development, polymorphism and protection

Much of the variation among insects is derived from the different ways that chitin has been moulded to form rigid structures, both internal and external. In this study, we identify a highly conserved expression pattern in an insect-only gene family, the Osiris genes, that is essential for development, but also plays a significant role in phenotypic plasticity and in immunity/toxicity responses. The majority of Osiris genes exist in a highly syntenic cluster, and the cluster itself appears to have arisen very early in the evolution of insects. We used developmental gene expression in the fruit fly, Drosophila melanogaster, the bumble bee, Bombus terrestris, the harvester ant, Pogonomyrmex barbatus, and the wood ant, Formica exsecta, to compare patterns of Osiris gene expression both during development and between alternate caste phenotypes in the polymorphic social insects. Developmental gene expression of Osiris genes is highly conserved across species and correlated with gene location and evolutionary history. The social insect castes are highly divergent in pupal Osiris gene expression. Sets of co-expressed genes that include Osiris genes are enriched in gene ontology terms related to chitin/cuticle and peptidase activity. Osiris genes are essential for cuticle formation in both embryos and pupae, and genes co-expressed with Osiris genes affect wing development. Additionally, Osiris genes and those co-expressed seem to play a conserved role in insect toxicology defences and digestion. Given their role in development, plasticity, and protection, we propose that the Osiris genes play a central role in insect adaptive evolution.

[Isolated left ventricular congenital diverticulum in adult: Report of cardiac imaging]

Cardiac diverticulum is an infrequent congenital malformation, it's even more rare in adulthood. It's often associated with other thoraco-abdominal diverticulums, and rarely isolated. The diagnosis relies on echocardiography. By the way, the magnetic resonance imagery (MRI) allows a finer analysis of the diverticulum, its topography and its situation contributed to vascular and cardiac structures, it has largely replaced the ventriculography. We report in this article the case of a patient of 36 years whose diagnosis of the diverticulum was made by transthoracic echocardiography (TTE) at the time of an assessment of dyspnea, this exam also objectified a mitral insufficiency by deformation and dilatation of the mitral annulus. Radiological assessment was completed by a transoesophageal echocardiography (TOE) and magnetic resonance imagery (MRI). Surgical treatment consisted of surgical closing of the diverticulum and mitral annuloplasty.

Healthcare-associated infective endocarditis: an undesirable effect of healthcare universalization

Invasive medical technology has led to an increase in the incidence of healthcare-associated infective endocarditis (HAIE). A prospective multicentre cohort study was conducted at seven hospitals in Andalusia, Spain, to establish the characteristics of HAIE and to compare them with those of community-acquired infective endocarditis (CAIE). HAIE was defined as either infective endocarditis (IE) manifesting >48 h after admission to hospital, or IE associated with a significant invasive procedure performed in the 6 months before diagnosis. Seven hundred and ninety-three cases of IE were investigated, and HAIE accounted for 127 (16%). As compared with patients with CAIE, patients with HAIE were older (60.1 ± 14.4 years vs. 53.6 ± 17.5 years) and had more comorbidities (Charlson index 3.3 ± 2.3 vs. 1.8 ± 2.3) and staphylococcal infections (58.3% vs. 24.8%). Vascular manipulation was the main cause of bacteraemia responsible for HAIE (63%). Peripheral vein catheter-associated bacteraemia accounted for 32.8% of the catheter-related bacteraemias. In-hospital mortality (44.9% vs. 24.2%) was higher in the HAIE group. Septic shock (OR 2.2, 95% CI 2.9-30.2) and surgery not performed because of high surgical risk (OR 1.6, 95% CI 1.2-20) were independent predictors of mortality in HAIE. The present study demonstrates that HAIE is a growing health problem associated with high mortality. Careful management of vascular devices is essential to minimize the risk of bacteraemias leading to HAIE.

Streptococcus agalactiae left-sided infective endocarditis. Analysis of 27 cases from a multicentric cohort

SUMMARY OBJECTIVE

To evaluate the current trends in the clinical characteristics and the prognosis of Streptococcus agalactiae infective endocarditis (IE), uncommon disease associated with high mortality.

METHODS

Descriptive analysis of 27 cases of a large cohort (961 episodes) of infective endocarditis collected in seven hospitals of Andalusia (Spain) between 1984 and 2008.

RESULTS

Native valves were affected in most cases (85. 2%), multiple valves were frequently involved (22.2%). The median age of the patients was 65 (51-76) years (59.3% men), with a comorbidity, according to the Charlson index, of 2.6+/-2.3. The most frequent underlying diseases were diabetes mellitus (25.9%), chronic obstructive pulmonary disease (14.8%), neoplasms (14.8%), urological disorders (11%) and chronic liver disease (11%). Clinical presentation was characterized by rapid worsening (median of 9 (5.7-15) days from onset of symptoms until diagnosis), a high rate of embolisms (37%) and cardiac complications (abscesses, fistulas or valve rupture) - 37% of cases. Surgery was performed in 12 patients (44.4%) and a high mortality (40.7%) was observed.

CONCLUSION

S. agalactiae IE is a serious disease with aggressive course and high mortality rate and affects patients with debilitating diseases. We must be alert of the development of complications and consider early valve surgery when it is necessary.

[Right intracardiac thrombus in Behçet's disease]

The authors report the clinical history of a 22-year-old woman, followed for Behçet's disease, who presented a prolonged fever for two months associated with oral and genital ulcerations. There was an inflammatory syndrome, papillary oedema without brain injury. Echocardiography revealed moderate pericardial effusion and voluminous thrombosis of right atria and right ventricle. Chest computed tomography showed a lung infarction without thrombosis of pulmonary artery. The antiphospholipid antibodies were negatives. The treatment was based on corticotherapy and anticoagulation with a good outcome. In Behçet disease, cardiac involvement manifestations as pericardial, myocardial or endocardial lesions. This case underlines the rarity of cardiac thrombosis in Behçet disease.

[Cardiovascular abnormalities of the antiphospholipid antibody syndrome]

The antiphospholipid antibody syndrome (APS) may present with serious cardiovascular complications which should be recognised by the cardiologist. The authors report a series of 6 cases of APS diagnosed after thrombotic events and the finding of antiphospholipid antibodies. The APS was primary in 5 cases and associated with tuberculous lymphadenitis in 1 case. There was cardiac involvement in 5 patients with pericardial effusion in 3 cases, complicated by tamponade as the presenting sign of primary APS in the other 2, valvular disease in one case (moderate mitral stenosis with aortic valve disease) and pulmonary embolism in one case. Five patients developed recurrent deep vein thrombosis of the legs. One patient had a transient ischaemic cerebral attack.

[Aneurysm of the posterior sinus of Valsalva ruptured into right atrium]

Sinus of Valsalva aneurysm is rare malformation, which takes origin from one of the three aortic sinuses. Diagnosis of this abnormality is usually made when rupture has occurred. Our observation underlines the severity of the posterior sinus of Valsalva aneurysm ruptured into right atrium, and emphasizes the utility of transthoracic and transoesophageal echocardiography for diagnosis.

Developmental effects of a chimeric ultraspiracle gene derived from Drosophila and Chironomus

The ultraspiracle (usp) gene encodes a nuclear receptor that forms a heterodimer with the ecdysone receptor (EcR) to mediate transcriptional responses to the insect steroid hormone, 20-hydroxyecdysone (20HE). The responses ultimately elicit changes associated with molting and metamorphosis. Although Ultraspiracle (USP) is required at several developmental times, it is unclear whether USP plays stage-specific roles in Drosophila. A chimeric transgene (d/cusp), produced by replacing the ligand-binding domain (LBD) of Drosophila USP with the equivalent domain from another Diptera, Chironomus tentans, was tested for its ability to rescue Drosophila usp mutants from early larval lethality. A single copy of the d/cusp was sufficient to rescue transformants from several lines through larval development but they died suddenly during the late third instar. Additional doses of d/cusp were required to allow survival through the adult stage, but they did not restore a normal prepupal contraction. Thus, the arrest at the onset of metamorphosis apparently is caused by the impaired ability of the chimeric USP to mediate a stage-specific function associated with the LBD.

[Heart failure and arterial hypertension disclosing amyloidosis]

Amyloidosis results from protein infiltration of the extracellular space of organs and tissues. Several amyloidosis proteins have been identified. Protein AL, (deriving from immunoglobulin light chain), protein AA and prealbumin are the most involved in this disease. When AL amyloidosis involves the heart, the illness is often terminal. Most clinical symptoms are heart failure and arrhythmia or block conduction. This case was characterised by the unusual combination of hypertension and amyloidosis. The diagnosis suggested by the echocardiographic but was confirmed by the damaged organ's biopsy. The present case concerns a young woman, who has hypertension and a pulmonary oedema. The echocardiographic scan showed a septal hypertrophy with a shining and granite-like aspect which is compatible with heart amyloidosis. Systolic and diastolic disorder with mitral and aortic regurgitation were also revealed. The kidney and rectum biopsies confirmed amyloidosis AL of the Kappa dysglobulinemia type, without extraosseous plasmocytoma. The heart and kidney failure symptoms disappeared after treatment with diuretics and ACE inhibitors.

[Imaging in cardiac hydatid cyst. Apropos of a case]

Cardiac hydatid disease is rare. Its dificult diagnosis is based on a series of arguments in which hydatid serology and imaging play a predominant role. A young patient with multiple cardiac hydatid cysts was investigated by 2D echocardiography, transoesophageal echocardiography and magnetic resonance imaging. This case illustrates the value of the various noninvasive imaging techniques in the diagnosis of cardiac hydatid disease and emphasizes the importance of surgical treatment before the development of complications.

[Adenocarcinoma of the appendix. Apropos of 11 new cases]

The authors review 11 new cases of adenocarcinoma of the appendix and 220 other cases drawn from the literature. In the first series, 6 patients presented with abscess or perforations. The tumor was proximal in 5, distal in 2, medial in 2, and total in 2. It extended to the cecum in 4 cases and to the lymph nodes in two. The clinical picture was one of appendicitis in seven patients, an iliac growth in three and occlusion in one. The diagnosis was made by the surgeon in four cases, and by postoperative histological examination in seven. The authors stress the need to open the appendix at operation, to take frozen sections in the event of any doubts, and systematic postoperative histological examination of operative specimens. Appendectomy is a poor solution, even accompanied by partial cecectomy, the survival rate at five years being only 20 %. It is only licit for a unperforated, proximal mucosal or submucosal tumor. The best solution is immediate or secondary right hemicolectomy, for which the survival rate, of 45 % at five years, is close to that of other forms of colic cancers.