Premitotic DNA synthesis in the brain of the adult frog (Rana esculenta L.): An autoradiographic 3H-thymidine study

Replicative synthesis of DNA in the brain of the adult frog was studied by light microscope autoradiography. Animals collected during the active period (May–June) and in hibernation (January) were used. In active frogs, 3H-thymidine labelling occurred mainly in the ependymal cells which line the ventricles. The mean labelling index (LI%) was higher in the ependyma of the lateral and fourth ventricles than in the ependyma of the lateral diencephalon and tectal parts of the mesencephalon. In the recessus infundibularis and preopticus the number of labelled cells (LCs) was several times greater than in the lateral parts of the third ventricle. LCs were seen subependymally only occasionally. The incidence of LCs in the parenchyma of the brain was much lower in most regions than in the ventricular ependyma; LCs were mainly small and, from their nuclear morphology, they were glial cells. The LI% reached the highest value in the septum hippocampi and in the nucleus entopeduncularis. In these locations, LCs were larger and closer in size to the nerve cells of these regions. From comparison with data obtained earlier in the brain of mammals, it is evident that the distribution of proliferating cells in the olfactory and limbic system is phylogenetically conservative. The occurrence of pyknotic cells in the same areas which contain LCs, suggests that cell division reflects in part the process of cell renewal observed in mammals. However, proliferating cells could also be linked to the continuous growth observed in non-mammalian vertebrates. In hibernating frogs, LCs and pyknoses were not seen or were found occasionally, which further indicates the functional significance of both processes.     

Haemostasis contact system and fibrinolysis in hereditary angioedema (C1-inhibitor deficiency)

Factors of the classical complement pathway, the contact system and fibrinolysis were evaluated both with functional and immunochemical methods, in patients with inherited deficiency of C1-inhibitor. Evaluations were performed under basal conditions, during acute attacks and during prophylaxis with low doses of anabolic steroids. Patients in the basal state showed no significant abnormalities of any of the parameters that we investigated. During acute attacks a slightly reduced prekallikrein concentration was registered. During treatment with low doses of danazol and stanozolol, protein C and plasminogen were found to be increased. Our data suggest that C1-inhibitor deficiency per se does not lead to a derangement of the fibrinolysis and coagulation contact system, and that the kinin system may be involved during acute attacks of angioedema.     

Measurement of troponin I 48 h after admission as a tool to rule out impaired left ventricular function in patients with a first myocardial infarction.

Few studies have evaluated cardiac troponin I (cTnI) as a marker for infarct size and left ventricular (LV) dysfunction. Here we investigated the ability of a single-point cTnI, measured with a second-generation assay (Access AccuTnI), to estimate infarct size and assess LV function in patients with a first myocardial infarction (AMI). cTnI measurements were performed 12 and 48 h after admission in 63 consecutive AMI patients. LV function was evaluated by gated single-photon emission computed tomography (SPECT) and infarct size was estimated by CK-MB peak and SPECT myocardial perfusion. LV function and infarct size were evaluated by SPECT before hospital discharge. SPECT was also repeated 3 months later. Significant correlations (p<0.001) were found between cTnI at 12 and 48 h and both the peak CK-MB (r=0.61 and r=0.82, respectively) and the perfusion defect size at SPECT (r=0.55 and r=0.61, respectively). cTnI at 12 and 48 h were inversely related (p<0.001) to LV ejection fraction (LVEF) assessed both early (r=-0.45 and r=-0.57, respectively) and 3 months after AMI (r=-0.51 and r=-0.69, respectively). cTnI >14.8 microg/L at 48 h predicted an LVEF <40% at 3 months with a sensitivity of 100% [95% confidence interval (CI) 73.5-100%], specificity of 65% (CI 49-79%), and a negative predictive value of 100%. Our findings demonstrate that a single cTnI measurement 48 h after admission is useful for ruling out impaired LV function in a routine clinical setting.     

Possible Identification of Cervicogenic Headache Among Patients With Migraine: An Analysis of 374 Headaches

According to Sjaastad, the pain in cervicogenic headache, a form not recognized by the IHS, is long lasting and always side-locked unilateral. The frequency of side-locked unilateral pain (defined here as no change in side from onset) and other characteristics of cervicogenic headache were investigated in 300 outpatients using information collected on standard forms in structured interviews. Three hundred seventy-four headaches diagnosed according to IHS criteria were identified. Three hundred forty-eight of these headaches were long-lasting (duration of more than 4 hours); migraine (65%) followed by tension-type headache (25%) were the commonest forms. Side-locked unilaterality was present in 29% (101 of 348), and occurred most frequently in migrainous disorders not fulfilling the criteria (25 of 56, 44.6%). This group differed significantly from the other migraine conditions for longer pain duration ( P <0.02) and less frequent nausea, vomiting, photophobia, phonophobia ( P <0.0001), and aggravation by physical activity ( P <0.02). With these characteristics, this group resembled cervicogenic headache. However, in none of these patients was pain triggered by head or neck movements, and the frequency of head or neck trauma did not differ from other headaches. A more precise definition of clinical criteria for cervicogenic headache vs migraine is, therefore, required.     

The use of physical restraints in an acute care hospital

To fill the knownledge gap on the extension and quality of physical restraints in acute care hospitals a survey aiming at evaluating knowledge, opinions and behaviours of nurses in this area of care was performed. A questionnaire administered to the nurses of a large Italian hospital obtained a response rate of 66.2% (227 nurses) and the situation of 77 patients (15.8% of admitted patients) hospitalised and constrained in the target wards was reported. The physical restraints were widely used in intensive care and medical specialty wards (bed rails and limbs constraints). The main reasons for restraining the patients were: disorientation, agitation, aggressiveness, and balance disturbances. The application of constraints is an autonomous of the nurses decision in 60.8% of cases and the information is seldom reported in clinical or nursing records. Fifty-two per cent of nurses feel uneasy in constraining patients because of the relational implications with relatives. Lack of knowledge on ethical and legal implications and on the possible negative effects of constraining patients, on the different forms of constriction and on alternative strategies warrant an educational intervention to control and improve the implementation of physical measures of containment.     

Rapid determination of brain natriuretic peptide in patients with acute myocardial infarction.

We evaluated a rapid brain natriuretic peptide (BNP) assay (Triage BNP, Biosite Diagnostics) as indicator of infarct size, left ventricular (LV) dysfunction, and longterm survival in patients with acute myocardial infarction (AMI) during the coronary care unit stay. We studied 64 AMI patients in whom infarct size was estimated by creatine kinase isoenzyme MB (CK-MB) peak concentrations and single-photon emission computed tomography (SPECT) myocardial perfusion using technetium-99m sestamibi, and LV function by gated SPECT imaging. Measurements of BNP and SPECT were performed approximately 3 days after admission. SPECT was also repeated 3 months later. We found a significant correlation between BNP and both the peak CK-MB concentrations (r = 0.40, p = 0.001) and the perfusion defect size at SPECT (r = 0.38, p = 0.002). BNP was weakly related to LV ejection fraction (LVEF) assessed both early and 3 months after AMI (r = -0.29, p = 0.02; and r = -0.27, p = 0.04, respectively). The sensitivity and specificity of BNP for predicting survival of patients over 1 year of follow-up was 100% and 43%, respectively, with a negative predictive value of 100%. The positive predictive power of BNP was very modest (12%). Considering our results, the measurement of BNP did not look nearly as promising when tested in the setting of our cardiological intensive care.     

Risk factors in multiple sclerosis: a population-based case–control study in Sicily. Background and methods

Incidence of multiple sclerosis (MS) has steeply increased over time during the last 30 years in the city of Catania. We carried out a population-based case–control study to evaluate the possible role of both environmental and genetic factors. From 1975 to 2004 in Catania, 367 MS patients diagnosed according to the Poser’s criteria had the onset of disease. A sample of MS patients was randomly selected from this incident cohort. Three controls matched by age and sex were randomly selected from the rosters of 14 GPs. Controls were proportionally selected according to the distribution by municipality of the target population using a multistage sampling methods. All cases and controls underwent a face-to-face interview to record information concerning environmental factors and a blood sample was taken for serological and genetic analysis. 164 MS patients (64 % women; mean age of 46.4 ± 10.7) and 481 controls (69 % women; mean age of 47.7 ± 14.8) were enrolled in the study. The distribution of the whole population and the selected controls by municipalities was similar. A blood sample was taken from 150 MS cases and from 337 controls. At the end of the enrolment, we obtained a representative sample of the MS cases and population controls avoiding possible selection bias. Participation rate was very high also concerning the collection of biological specimens.     

Cholesterol hydroperoxides generate singlet molecular oxygen [O(2) ((1)Δ(g))]: near-IR emission, (18)O-labeled hydroperoxides, and mass spectrometry

In mammalian membranes, cholesterol is concentrated in lipid rafts. The generation of cholesterol hydroperoxides (ChOOHs) and their decomposition products induces various types of cell damage. The decomposition of some organic hydroperoxides into peroxyl radicals is known to be a potential source of singlet molecular oxygen [O(2) ((1)Δ(g))] in biological systems. We report herein on evidence of the generation of O(2) ((1)Δ(g)) from ChOOH isomers in solution or in liposomes containing ChOOHs, which involves a cyclic mechanism from a linear tetraoxide intermediate originally proposed by Russell. Characteristic light emission at 1270 nm, corresponding to O(2) ((1)Δ(g)) monomolecular decay, was observed for each ChOOH isomer or in liposomes containing ChOOHs. Moreover, the presence of O(2) ((1)Δ(g)) was unequivocally demonstrated using the direct spectral characterization of near-infrared light emission. Using (18)O-labeled cholesterol hydroperoxide (Ch(18)O(18)OH), we observed the formation of (18)O-labeled O(2) ((1)Δ(g)) [(18)O(2) ((1)Δ(g))] by the chemical trapping of (18)O(2) ((1)Δ(g)) with 9,10-diphenylanthracene (DPA) and detected the corresponding (18)O-labeled DPA endoperoxide (DPA(18)O(18)O) and the (18)O-labeled products of the Russell mechanism using high-performance liquid chromatography coupled to tandem mass spectrometry. Photoemission properties and chemical trapping clearly demonstrate that the decomposition of Ch(18)O(18)OH generates (18)O(2) ((1)Δ(g)), which is consistent with the Russell mechanism and points to the involvement of O(2) ((1)Δ(g)) in cholesterol hydroperoxide-mediated cytotoxicity.     

Role of quercetin in preventing thioacetamide-induced liver injury in rats

In hepatic toxicity induced in rats by two injections of thioacetamide (TAA, 350 mg/kg with an interval of 8 hr), the action of quercetin was investigated. After 96 hr, TAA administration resulted in hepatic necrosis, significant increases in serum transaminase activity, and increases in hepatic lipoperoxidation. Thioacetamide-induced hepatotoxicity also showed changes in antioxidant enzymes in the liver of rats, with alterations in p-ERK 1/2 (phosphorylated extracellular-signal related kinase 1/2) as well as an imbalance between proapototic protein Bax and anti-apoptotic protein Bcl-2 expression. With administration of the flavonoid quercetin (50 mg/Kg i.p.) for four consecutive days following TAA, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity were close to normal values in rats. Histological findings suggested that quercetin had a preventive effect on TAA-induced hepatic necrosis. Quercetin treatment caused significant decreases in lipid peroxide levels in the TAA-treated rats, with some changes in antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Quercetin also inhibited the change of the p-ERK1/2 by TAA and significantly prevented the increase in Bax/Bcl-2 ratio, thus preventing apoptosis. Findings indicate that quercetin may have a preventive effect on TAA-induced hepatotoxicity by modulating the oxidative stress parameters and apoptosis pathway.     

Rosmarinic acid as a protective agent against genotoxicity of ethanol in mice

The aim of the present work was to study the protective effects of rosmarinic acid against ethanol-induced DNA damage in mice. The antigenotoxic capacity of rosmarinic acid (100 mg/kg) was tested using pre-, co- and post-treatment with ethanol (5 g/kg). Peripheral blood (1 and 24 h) and brain cells (24 h) were evaluated using the comet assay and bone marrow was analyzed using the micronucleus assay (24 h). The results were compared to data of TBARS, enzymes with antioxidant activity, and DCFH-DA test. Peripheral blood and brain cells show that mean damage index (DI) and damage frequency (DF) values of ethanol with pre-treatment with rosmarinic acid group were significantly lower than in the ethanol group. In brain cells all different treatments with ethanol and rosmarinic acid showed significant decrease in DI and DF mean values when compared to ethanol group and negative control. No significant differences were observed in micronucleus frequency, activity of antioxidant enzymes and TBARS between groups. The DCFH-DA test show a reduction of 18% of fluorescence intensity when compare with ethanol group. The results show that rosmarinic acid could decrease the levels of DNA damage induced by ethanol, for both tissues and treatment periods.