Cardiac and Vascular α1-Adrenoceptors in Congestive Heart Failure: A Systematic Review

As heart failure (HF) is a devastating health problem worldwide, a better understanding and the development of more effective therapeutic approaches are required. HF is characterized by sympathetic system activation which stimulates α- and β-adrenoceptors (ARs). The exposure of the cardiovascular system to the increased locally released and circulating levels of catecholamines leads to a well-described downregulation and desensitization of β-ARs. However, information on the role of α-AR is limited. We have performed a systematic literature review examining the role of both cardiac and vascular α1-ARs in HF using 5 databases for our search. All three α1-AR subtypes (α1A, α1B and α1D) are expressed in human and animal hearts and blood vessels in a tissue-dependent manner. We summarize the changes observed in HF regarding the density, signaling and responses of α1-ARs. Conflicting findings arise from different studies concerning the influence that HF has on α1-AR expression and function; in contrast to β-ARs there is no consistent evidence for down-regulation or desensitization of cardiac or vascular α1-ARs. Whether α1-ARs are a therapeutic target in HF remains a matter of debate

Ectopic Cushing' syndrome caused by a neuroendocrine carcinoma of the mesentery

BACKGROUND: ACTH overproduction within the pituitary gland or ectopically leads to hypercortisolism. Here, we report the first case of Cushing' syndrome caused by an ectopic ACTH-secreting neuroendocrine carcinoma of the mesentery. Moreover, diagnostic procedures and pitfalls associated with ectopic ACTH-secreting tumors are demonstrated and discussed. CASE PRESENTATION: A 41 year-old man presented with clinical features and biochemical tests suggestive of ectopic Cushing's syndrome. First, subtotal thyroidectomy was performed without remission of hypercortisolism, because an octreotide scan showed increased activity in the left thyroid gland and an ultrasound revealed nodules in both thyroid lobes one of which was autonomous. In addition, the patient had a 3 mm hypoenhancing lesion of the neurohypophysis and a 1 cm large adrenal tumor. Surgical removal of the pituitary lesion within the posterior lobe did not improve hypercortisolism and we continued to treat the patient with metyrapone to block cortisol production. At 18-months follow-up from initial presentation, we detected an ACTH-producing neuroendocrine carcinoma of the mesentery by using a combination of octreotide scan, computed tomography scan, and positron emission tomography. Intraoperatively, use of a gamma probe after administration of radiolabeled (111)In-pentetreotide helped identify the mesenteric neuroendocrine tumor. After removal of this carcinoma, the patient improved clinically. Laboratory testing confirmed remission of hypercortisolism. An octreotide scan 7 months after surgery showed normal results. CONCLUSION: This case underscores the diagnostic challenge in identifying an ectopic ACTH-producing tumor and the pluripotency of cells, in this case of mesenteric cells that can start producing and secreting ACTH. It thereby helps elucidate the pathogenesis of neuroendocrine tumors. This case also suggests that patients with ectopic Cushing's syndrome and an octreotide scan positive in atypical locations may benefit from explorative radioguided surgery using (111)In-pentetreotide and a gamma probe

IMMUNOPROTECTION IN SPONTANEOUS REMISSION OF TYPE-1 DIABETES - LONG-TERM FOLLOW-UP RESULTS

This prospective pilot study was undertaken to test the efficacy of oral methyl-prednisolone (MP) therapy at spontaneous remission phase of type 1 diabetes in intervening the course of the disease. Twenty-five type 1 diabetic patients who were classified as having a spontaneous remission (honeymoon) were divided into treatment and non-treatment groups on voluntary basis. Fifteen patients thus making up the treatment group (13 males and 2 females, mean age 23.8 +/- 6.2 years) received 0.7-1.0 mg/kg/day of MP p.o. for 2 weeks. The dose of the drug was then gradually diminished every week until 5 mg/day (approx. 0.1 mg/kg/day) and discontinued at 10 +/- 2 weeks. In case of hyperglycemia occurring in 12 of 15 patients due to the administration of steroid, insulin was used to normalize blood glucose levels (average 0.47 +/- 0.21 IU/kg/day). The non-treatment group (8 males and 2 females, mean age 21.8 +/- 8.9) did not receive any special medication or placebo except for insulin whenever necessary to regulate glycemia. Upon completion of protocol, all patients in treatment group displayed clinical remission with 10 still in non-insulin requiring remission for follow-up periods ranging between 16 and 91 months. The remaining 5 patients relapsed within 3-15 months of therapy. Other metabolic (including basal and stimulated C-peptide levels) and immunological indices that have spontaneously ameliorated with the occurrence of honeymoon were also maintained within normal range in the NIR patients. Meanwhile, natural remission in the non-MP-treated group terminated at 3.4 +/- 0.6 months with deterioration of all metabolic and immunological markers as well as increasing requirements for insulin. In conclusion, the spontaneous remission of the patients could be prolonged significantly by MP terapy as opposed to no therapy (P < 0.001). These results suggest that the spontaneous remission phase may be a crucial point of intervention in immunotherapy of type 1 diabetes and that randomized trials with MP at this particular phase would be worthwhile

Seismic Reliability of Highway Transportation Systems

Assessment of the reliability of lifelines under seismic loads requires particular attention, since the proper functioning of these systems during or after a destructive earthquake is very important. The main objective of this study is to investigate the system reliability of lifeline networks subjected to earthquake loads by concentrating on highway transportation systems consisting of viaducts, bridges, roads, and highways. Seismic reliability of a structural component is determined based on the seismic capacity of the component and earthquake loads acting on it. The future earthquake threat on the components is calculated by performing a probabilistic seismic hazard analysis. Failure reasons of bridges and asphalt roads are explained and behavior of these components under earthquake loads is discussed to determine the seismic capacities of them. In this respect, the system reliability concepts are used and bounds on the seismic reliability of a system are established. A case study based on real-life data is also presented in order to illustrate the implementation of the method. (C) 2018 American Society of Civil Engineers

Effect of rosiglitazone on peroxisome proliferator‐activated receptor γ gene expression in human adipose tissue is limited by antiretroviral drug–induced mitochondrial dysfunction

Background. Treatment of human immunodeficiency virus (HIV)-1 with thymidine-analogue nucleoside reverse-transcriptase inhibitors (tNRTIs) causes lipoatrophy, mitochondrial toxicity, and lower adipose tissue expression of peroxisome proliferator-activated receptor γ (PPARγ [PPARG gene]) . Rosiglitazone (RSG), a PPARγ agonist, improves congenital lipoatrophy but not HIV lipoatrophy. Methods. Serial fat biopsies were taken from HIV-infected, lipoatrophic men randomized to receive RSG or placebo for 48 weeks. Adipose tissue mitochondrial and nuclear gene expression and mitochondrial DNA content were quantified by real-time polymerase chain reaction. Nonparametric analyses were applied. Results. Subjects receiving tNRTI-containing antiretroviral therapy had lower baseline mitochondrial RNA expression and DNA content. In subjects receiving tNRTIs, exposure to RSG did not affect PPARG expression at either week 2 or 48. At week 2, RSG increased PPARG expression only in subjects not treated with tNRTIs, whereas at week 48, increased PPARG expression was observed in subjects not treated with tNRTIs, regardless of RSG use. Similar findings were observed for the PPARG-responsive gene fatty acid-binding protein 4. Changes in PPARG expression were associated with increases in limb fat mass. Conclusions. These data suggest that in HIV-infected, lipoatrophic men, adipose PPARG expression and function are dependent on intact mitochondrial function. These data support a direct link between mitochondrial toxicity and adipose tissue PPARG expression and help explain the poor clinical response to RSG observed in clinical trials