Popliteal artery entrapment syndrome

Three cases of popliteal artery entrapment syndrome, one of them bilateral, are presented with a review of the literature, with special reference to the embryological development of the popliteal space and the diagnostic and therapeutic problems presented by this syndrome.     

Expression and carbonylation of creatine kinase in the quadriceps femoris muscles of patients with chronic obstructive pulmonary disease

Oxidative protein modification involving carbonylation has recently been identified as an important factor in skeletal muscle dysfunction in patients with chronic obstructive pulmonary disease (COPD). However, the exact identity of modified proteins inside limb muscles of patients with COPD remains unknown. We used 2D electrophoresis, immunoblotting, and mass spectrometry to identify carbonylated proteins in the vastus lateralis muscle of 12 patients with COPD and 6 control subjects. Both creatine kinase (CK) and carbonic anhydrase III (CAIII) were identified as being strongly carbonylated in this muscle in both groups of subjects. Total CK activity, CK protein expression, and the intensity of CK carbonylation were significantly greater in the muscles of patients with COPD as compared with control subjects, whereas CAIII protein expression and intensity of carbonylation were similar in the two groups. In patients with COPD, CK activity and protein expression correlated positively with FEV(1) and V O(2)max, whereas the intensity of CK carbonylation correlated negatively with the same parameters. These results indicate that oxygen radicals selectively target CK and CAIII inside limb muscles of humans. The observation that the intensity of CK carbonylation correlates negatively with CK activity in limb muscles of patients with COPD suggests that carbonylation may have a deleterious effect on CK activity, and may contribute to impaired CK function in the limb muscles of these patients.     

Cruzipain induces autoantibodies against cardiac muscarinic acetylcholine receptors. Functional and pathological implications

The goal of this study was to investigate whether cruzipain, a Trypanosoma cruzi immunodominant antigen, was able to induce antibodies reactive to the cardiac M(2) muscarinic acetylcholine receptor (M(2) mAChR). Immunization with cruzipain that was devoid of enzyme activity triggered IgG antibodies against cardiac M(2) mAChR. By radioligand competition assay we proved that the anti-cruzipain IgG fraction, purified from serum, inhibited binding of the specific M(2) mAChR radioligand [(3)H]quinuclidinyl benzilate. We also demonstrated that anti-cruzipain IgG reacted against the second extracellular loop of the M(2) mAChR. The corresponding affinity-purified serum anti-M(2)e2 IgG (reacting against a synthetic peptide corresponding to this loop in humans) displayed agonist-like activity associated with specific M(2) mAChR activation - increase of cGMP, inositol phosphate accumulation and nitric oxide synthase activity - triggering a decrease in myocardial contractility. Moreover, the same IgG fraction decreased heart frequency, related to inhibition of adenylate cyclase activity. These results imply that cruzipain plays a role in the production of antibodies against M(2) mAChR, which have been related to the pathogenesis of dysautonomic syndrome described in Chagas' disease.     

Early mutation of the neu (erbB-2) gene during ethylnitrosourea-induced oncogenesis in the rat Schwann cell lineage.

The development of malignant tumors of the peripheral nervous system (schwannomas) within a defined intracranial section of the rat trigeminal nerve ("trigeminal box") was used as a model to identify genetic alterations typically associated with the process of cell-lineage-specific oncogenesis induced by exposure to N-ethyl-N-nitrosourea on postnatal day 1. All 47 trigeminal schwannomas (and 12 extracranial neurinomas) investigated carried a T.A----A.T transversion mutation at nucleotide 2012 of the neu (erbB-2) gene sequence encoding the transmembrane domain of pg185neu. This mutation was absent in all 18 tumors in the brain and spinal cord (central nervous system) isolated from the same animals. Identical observations were made in cell lines derived from N-ethyl-N-nitrosourea-induced rat schwannomas vs. brain tumors. By asymmetric PCR and mutant-specific Mnl I restriction fragment length analyses, cells carrying the mutant neu allele became detectable and could be localized within the trigeminal box as early as 7 days after the carcinogen pulse. The proliferation rate of the mutant cells strongly exceeded that of the wild-type cells up to the time of maturation of the trigeminal nerve around postnatal day 30 and thereafter to a lesser extent until the appearance of schwannomas. A specific mutation of the neu gene thus represents a very early, probably the first, step in the malignant conversion of immature rat Schwann cells exposed to N-ethyl-N-nitrosourea in vivo and is diagnostic for a subset of proliferative cells at high risk of progressing toward the expression of fully malignant phenotypes. Loss of heterozygosity for the mutant neu allele is a candidate event for a critical second step in the process.     

Mediterranean Alcohol-Drinking Pattern and the Incidence of Cardiovascular Disease and Cardiovascular Mortality: The SUN Project

Background: We assessed the still unclear effect of the overall alcohol-drinking pattern, beyond the amount of alcohol consumed, on the incidence of cardiovascular clinical disease (CVD). Methods: We followed 14,651 participants during up to 14 years. We built a score assessing simultaneously seven dimensions of alcohol consumption to capture the conformity to a traditional Mediterranean alcohol-drinking pattern (MADP). It positively scored moderate alcohol intake, alcohol intake spread out over the week, low spirit consumption, preference for wine, red wine consumption, wine consumed during meals and avoidance of binge drinking. Results: During 142,177 person-years of follow-up, 127 incident cases of CVD (myocardial infarction, stroke or cardiovascular mortality) were identified. Compared with the category of better conformity with the MADP, the low-adherence group exhibited a non-significantly higher risk (HR) of total CVD ((95% CI) = 1.55 (0.58–4.16)). This direct association with a departure from the traditional MADP was even stronger for cardiovascular mortality (HR (95% CI) = 3.35 (0.77–14.5)). Nevertheless, all these associations were statistically non-significant. Conclusion: Better conformity with the MADP seemed to be associated with lower cardiovascular risk in most point estimates; however, no significant results were found and more powered studies are needed to clarify the role of the MADP on CVD.