Diagnosis of diffuse and localized arrhythmogenic right ventricular dysplasia by gated blood-pool SPECT.

This study aimed to assess the ability of global and local systolic parameters measured with gated blood-pool SPECT (GBPS) to diagnose and characterize the severity of diffuse or localized arrhythmogenic right ventricular dysplasia (ARVD). METHODS: Fifty-nine subjects with symptomatic ventricular arrhythmias were prospectively included in the study. With the International Society and Federation of Cardiology criteria for ARVD as a gold standard, these subjects were classified as subjects without ARVD (21 control subjects) and patients with localized ARVD (16 patients) or diffuse ARVD (22 patients). Right ventricular volumes, right ventricular ejection fractions (EF), the SD of local EF (sigma-EF), and the SD of the local times of end systole (sigma-TES) were computed from GBPS data and compared among the groups in the study population. RESULTS: sigma-EF did not differ between control subjects and patients with diffuse or localized ARVD. Right ventricular EF and volumes differed between patients with diffuse ARVD and control subjects, with similar areas under the receiver-operating-characteristic curves, but right ventricular EF and volumes failed to differentiate patients with localized ARVD. In contrast, sigma-TES differed between patients with diffuse or localized ARVD and control subjects. Regression analysis showed that the systolic parameter most strongly associated with the diagnosis of ARVD was sigma-TES. The probabilities of a randomly chosen patient in the diffuse ARVD group and of a randomly chosen patient in the localized ARVD group having sigma-TES values greater than that of a randomly chosen control subject were 98.5% and 96.7%, respectively. For the diagnosis of localized ARVD, a threshold of 80 ms for sigma-TES corresponded to sensitivity, specificity, and positive and negative predictive values of 100%, 81%, 80%, and 100%, respectively. CONCLUSION: With GBPS, both diffuse ARVD and localized ARVD can be accurately diagnosed by computing sigma-TES for all of the pixels on the surface of the right ventricle.     

Human leukocyte antigen and adult living-donor liver transplantation outcomes: an analysis of the organ procurement and transplantation network database.

Human leukocyte antigen (HLA) compatibility has no clinically significant impact in cadaveric liver transplantation. Less is known regarding living-donor liver transplantation (LDLT). Our prior analysis of the Organ Procurement and Transplantation Network (OPTN) database suggested a higher graft failure rate in patients who underwent LDLT from donors with close HLA match. We further investigated the effect of HLA-A, -B, and -DR matching on 5-yr graft survival in adult LDLT by analyzing OPTN data regarding adult LDLT performed between 1998 and 2005. We evaluated associations between 5-yr graft survival and total, locus-specific, and haplotype match levels. Separate analyses were conducted for recipients with autoimmune (fulminant autoimmune hepatitis, cirrhosis secondary to autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis) or nonautoimmune liver disease. Multivariable Cox proportional hazard models were used to evaluate interactions and adjust for potential confounders. Among 631 patients with available donor/recipient HLA data, the degree of HLA match had no significant effect on 5-yr graft survival, even when analyzed separately in recipients with autoimmune vs. nonautoimmune liver disease. To be able to include all 1,838 adult LDLTs, we considered a first-degree related donor as substitute for a close HLA match. We found no difference in graft survival in related vs. unrelated pairs. In conclusion, our results show no detrimental impact of close HLA matching on graft survival in adult LDLT, including in recipients with underlying autoimmune liver disease.     

TSS and traditional surgery in hip and knee replacement

Surgery passes through a continuous evolution, thanks to the introduction of new technologies and techniques. Tissue-sparing surgery is a concept introduced in the last years to address prosthetic surgery to a more conservative fashion. We discuss the TSS decalogue with a critical eye, pointing out how traditional surgery is evolving in accordance with TSS statements. Proceedings of the Consensus Conference “TSS in hip and knee replacement”, Rapallo, Italy, 22–24 June 2006     

Plasma levels and vascular effects of vasopressin in patients undergoing coronary artery bypass grafting.

OBJECTIVE: Recent studies have suggested that endogenous vasopressin (AVP) acts as a spasmogen during coronary artery bypass grafting (CABG). Given that AVP could induce vasospasm in the grafted vessel, we assessed the release of this peptide during and after CABG, and explored ways of counteracting its contractile effect on the internal mammary artery (IMA). METHODS: Plasma levels of AVP were determined by radioimmunoassay in 16 patients before, during and after CABG. Using isometric force recording techniques, we also investigated the mechanisms involved in the contractile effect of AVP in ring preparations of IMA specimens taken from 95 patients. RESULTS: Plasma AVP levels peaked after the start of cardiopulmonary bypass (CPB) and correlated well with serum osmolality (Pearson's r=0.9490; P<0.0001; n=16). An inverse correlation was observed between plasma AVP levels recorded at this stage and the maximal contraction induced in vitro by AVP in vascular rings from the same patients (Pearson's r=-0.6968; P<0.01; n=16). No change in the AVP response was produced by endothelium removal, exposure to the NO precursor (3 x 10(-4)M L-arginine), inhibition of nitric oxide (NO) synthase (3 x 10(-5) M L-NAME) or soluble guanylate cyclase (3 x 10(-6) M 1H-[1,2,4]oxadiazol [4,3,-alpha]quinoxalin-1-one (ODQ)), removal of the superoxide anion (100 U/ml superoxide dismutase (SOD) plus 1200 U/ml catalase) or hydroxyl radical (10(-4) M deferoxamine), or specific alpha1 - (10(-6) M prazosin) or endothelin (10(-5) M bosentan) receptor antagonism. In contrast, adenylate cyclase activation (3 x 10(-8) M forskolin) reduced the contractile response to AVP, while prostanoid synthesis (3 x 10(-6) M indomethacin) inhibition and blockade of Ca2+ -activated potassium channels (KCa) (10(-3) M tetraethylammonium (TEA)) enhanced AVP contraction. Age, gender and smoking also modified the AVP response. CONCLUSION: Our findings suggest a role for AVP as a modulator of vascular tone in human IMA. The effect of AVP is dependent on prostanoids and Ca2+ -activated K+ channels, so its dysfunction in pathophysiological cardiovascular processes could mean that AVP, among other factors, produces vasospasm in IMA grafts.     

Effect of Zinc or S-Adenosyl-l-methionine on Long Term Administration of Low Doses of Lead to Rats

Two alternatives for the treatment of lead intoxication, administration of zinc or a thiol donor, S-adenosyl-L-methionine (SAM), were analysed. Rats were exposed to lead (Pb)-acetate (60 mg/1) in drinking water during 90 days; one group also received SO₄Zn in water (40 mg/l), while another received both Pb and SAM (5 mg/24 hr intraperitoneally. Erythrocytic δ-aminolaevulinic dehydratase (ALA-D) activity was significantly reduced (P<0.001) both in rats receiving Pb alone and in rats receiving Pb and each of the other two treatments. The high erythrocytic uroporphyrinogen synthetase (URO-S) activity noticed in Pb administered rats, was significantly (P< 0.001) reduced in animals treated either with zinc or with SAM. Hepatic ALA-D activity tended to decrease while renal enzyme activity was not modified by the low level Pb exposure used in this work. Interestingly, SAM treated rats in both tissues exhibited significantly (P<0.01) higher activities of the enzyme. It is argued that SAM treatment causes a surplus of thiols that allows the full expression of ALA-D catalytic activity.