Influence of hypertension and other risk factors on the onset of sublingual varices

Background: Sublingual varices (SV) are dilatations of tortuous veins that increased with age. Previous studies showed that this pathology could be correlated to some risk factors such as hypertension, age, gender and diabetes mellitus. In this study we evaluated, on a large number of subjects, the relationship between SV and different grades of hypertension as well as some risk factors extending the analysis to new risk factors such as dyslipidemia, obesity and antihypertensive therapy, modelling a possible dependence of SV on all these factors.Methods: In the study 1008 subjects, 284 with and 724 without SV, were examined. The blood pressure was measured in office condition and, to exclude subjects with white coat syndrome or masked hypertension, also using a 24 h Holter pressure monitor. Hypertensive subjects were divided in resistant, drugs controlled (compensated) and patients with prior unknown hypertension (new diagnosed) groups. The presence or absence of SV as well as of the risk factors was assessed clinically. We tested the influence of age on the presence of SV by using the chi-square test and the relation between each risk factor and SV by the Cochran-Mantel-Haenszel test. Finally, we carried out a multivariate regression tree analysis in order to predict the presence of SV.Results: We confirmed the influence of age on SV and found a significant relationship between SV and both the compensated and resistant hypertension grades. We highlighted a relationship between SV and dyslipidemia in subjects with new diagnosed hypertension, and between SV and smoking in subjects with compensated hypertension grade. The regression tree showed a classification accuracy of about 75% using as variables hypertension grades, age and antihypertensive treatment.Conclusions: We confirmed the SV dependence on age, resistant hypertension and smoking, highlighting a new association with dyslipidemia in new diagnosed hypertensive subjects and new relations depending on the hypertension grades. Thus, the SV inspection could be used to suggest a lipidologist as well as a hypertension specialist visit for a pharmacological and pressure check particularly in subjects presenting SV and dyslipidemia. However, further parameters are to be considered to improve the sensitivity of the prognostic tree model

Troponin T cross-linking in ischemic and apoptotic cardiomyocytes.

Intracellular calcium overload of guinea pig cardiomyocytes is accompanied by troponin T cross-linking, which is revealed by changes ill immunoreactivity of anti-troponin T antibodies, We presently investigated whether the same process is detectable in the human heart Immunohistochemistry shows myofibrillar staining with BN-59 anti-troponin T antibody with rare cardiomyocytes in samples obtained at surgery, whereas approximately 50% of myocytes are labeled in heart samples taken at autopsy within 3 hours of death, and every cardiomyocyte is stained after exposure of biopsy sections to 10 nmol/L calcium. Western blot analysis shows reactive polypeptides of approximately 70 and 85 to 90 kd in addition to troponin T in both treated and autopsy heart sections, Neither reactivity in immunohistochemistry nor additional reactive polypeptides in Western blot are detectable when calpain or transglutaminase is inhibited during exposure of sections to high calcium. Troponin T crosslinking occurs also in isolated myofibrils, which show staining with BN-59 at either sarcomeric A or I bands, Labeling with TdT-mediated dUTP nick end labeling (TUNEL) to demonstrate apoptosis reveals DNA fragmentation in BN-59-positive myocytes. Thus, troponin T cross-linking occurs in human cardiac myocytes concomitantly with apoptosis and autopsy autolysis, suggesting that similar cy cytosolic alterations can be produced by different types of myocyte death

Cardiomyocyte troponin T immunoreactivity is modified by cross- linking resulting from intracellular calcium overload.

Background During myocardial ischemia, the increase in cytosolic Ca2+ promotes the activation of neutral proteases such as calpains. Since the troponin T subunit is a substrate for calpains, we investigated the effects of irreversible myocyte damage on troponin T immunoreactivity. Methods and Results Hearts from adult guinea pigs (n=32) were perfused under conditions of normoxia, ischemia, postischemic reperfusion, or Ca2+ paradox. Hearts were frozen and processed for immunohistochemistry and Western blot with three anti-troponin T monoclonal antibodies. Two of these antibodies are unreactive on cryosections of freshly isolated and normoxic hearts and of hearts exposed to 30 minutes of no-flow ischemia. In contrast, reactivity is detected in rare myocytes after 60 minutes of ischemia, in a large population of myocytes after 60 minutes of ischemia followed by 30 minutes of reperfusion, and in every myocyte exposed to Ca2+ paradox. In Western blots, samples from ischemia-reperfusion and Ca2+-overloaded hearts show reactive polypeptides of about 240 to 260 kD and 65 to 66 kD in addition to troponin T. A similar pattern of immunoreactivity is observed with an anti-troponin I antibody. Histochemical troponin T immunoreactivity and reactivity on high-molecular-weight polypeptides are detectable in normal heart samples after preincubation with 10 mmol/L Ca2+ or with transglutaminase, whereas they are not if either transglutaminase or calpain is inhibited. Conclusions The evolution of the ischemic injury is accompanied by changes in troponin T immunoreactivity as a consequence of the calcium-dependent activation of both calpain proteolysis and transglutaminase cross-linking

TRANSGLUTAMINASE-CATALYZED POLYMERIZATION OF TROPONIN IN-VITRO

In the presence of calcium ions, tissue transglutaminase catalyzes the polymerization of skeletal muscle troponin to high molecular weight insoluble aggregate. The specific action of transglutaminase is proved by the isolation of glutamyl-spermidine isopeptide derivatives. The process involves mainly the troponin T subunit (TnT), with formation of dimers and trimers of TnT, which were reactive with specific antibodies by immunoblotting. Furthermore when incubation is carried out in the presence of radioactive polyamines, the label is incorporated selectively into TnT subunit

Overexpression of the stress-protein Grp94 reduces cardiomyocyte necrosis due to calcium overload and simulated ischemia

Increase in free intracellular calcium [Ca2+](i) plays a crucial role in cardiomyocyte ischemic injury. Here we demonstrate that overexpression of the sarcoplasmic-reticulum stress-protein Grp94 reduces myocyte necrosis due to calcium overload or simulated ischemia. Selective three-to eightfold Grp94 increase, with no change in Grp78 or calreticulin amount, was achieved by stable transfection of skeletal C2C12 and cardiac H9c2 muscle cells. After exposure to the calcium ionophore A23187, LDH release from five different Grp94-overexpressing clones of either C2C12 and H9c2 origin was significantly lower than that of control ones and [Ca2+](i) increase was significantly delayed. The number of necrotic cells, evaluated by propidium iodide uptake, was reduced when cells from the Grp94-overexpressing H9c2 clone were exposed to conditions simulating ischemia. Experiments performed in neonatal rat cardiomyocytes cotransfected with grp94 and the green fluorescent protein (GFP) cDNAs validated the protective effect of Grp94 overexpression. A lower percentage of propidium-iodide positive/GFP-fluorescent myocytes co-expressing exogenous Grp94, with respect to myocytes expressing GFP alone, was observed after exposure to either A23187 (6.6% vs. 14.0%, respectively) or simulated ischemia (8.5% vs. 17.7%, respectively). In conclusion, the selective increase in Grp94 protects cardiomyocytes from both ischemia and calcium overload counteracting [Ca2+](i) elevations