Thermal tolerance does not explain the altitudinal segregation of lowland and alpine aquatic insects

Elevation gradients provide powerful study systems for examining the influence of environmental filters in shaping species assemblages. High-mountain habitats host specific high-elevation assemblages, often comprising specialist species adapted to endure pronounced abiotic stress, while such harsh conditions prevent lowland species from colonizing or establishing. While thermal tolerance may drive the altitudinal segregation of ectotherms, its role in structuring aquatic insect communities remains poorly explored. This study investigates the role of thermal physiology in shaping the current distribution of high-mountain diving beetles from the Sierra Nevada Iberian mountain range and closely related lowland species. Cold tolerance of five species from each altitudinal zone was measured estimating the supercooling point (SCP), lower lethal temperature (LLT) and tolerance to ice enclosure, while heat tolerance was assessed from the heat coma temperature (HCT). Alpine species exhibited wider fundamental thermal niches than lowland species, likely associated with the broader range of climatic conditions in high-mountain areas. Cold tolerance did not seem to prevent lowland species from colonizing higher elevations, as most studied species were moderately freeze-tolerant. Therefore, fundamental thermal niches seem not to fully explain species segregation along elevation gradients, suggesting that other thermal tolerance traits, environmental factors, and biotic interactions may also play important roles.

A setup to measure the temperature-dependent heating power of magnetically heated nanoparticles up to high temperature

Magnetic heating, namely, the use of heat released by magnetic nanoparticles (MNPs) excited with a high-frequency magnetic field, has so far been mainly used for biological applications. More recently, it has been shown that this heat can be used to catalyze chemical reactions, some of them occurring at temperatures up to 700 °C. The full exploitation of MNP heating properties requires the knowledge of the temperature dependence of their heating power up to high temperatures. Here, a setup to perform such measurements is described based on the use of a pyrometer for high-temperature measurements and on a protocol based on the acquisition of cooling curves, which allows us to take into account calorimeter losses. We demonstrate that the setup permits to perform measurements under a controlled atmosphere on solid state samples up to 550 °C. It should in principle be able to perform measurements up to 900 °C. The method, uncertainties, and possible artifacts are described and analyzed in detail. The influence on losses of putting under vacuum different parts of the calorimeter is measured. To illustrate the setup possibilities, the temperature dependence of heating power is measured on four samples displaying very different behaviors. Their heating power increases or decreases with temperature, displaying temperature sensibilities ranging from -2.5 to +4.4% K^-1. This setup is useful to characterize the MNPs for magnetically heated catalysis applications and to produce data that will be used to test models permitting to predict the temperature dependence of MNP heating power.

Effect of Spin Clustering on Basic and Relaxometric Properties of Magnetic Nanoparticles

An increasing awareness about novel medical applications of smaller, inorganic-based nanoparticles, possessing unique properties at the nanoscale, has led to a burst of research activities in the development of "nanoprobes" for diagnostic medicine and agents for novel, externally activated therapies. In this research field magnetic nanoparticles are prominent due to fundamental peculiar properties particularly appealing for their use in materials and biomedical applications. Aiming to study the relationship between the topology of the magnetic nanoparticles and their efficacy as MRI contrast agents (relaxometric properties), we prepared three different stable colloidal suspension (ferrofluid) of magnetic nanobeads (MNBs) constituted by a discrete number of maghemite nanoparticles, arranged in disordered clusters or ordered in a polymeric matrix. An accurate morpho-dimensional and magnetic characterization displays the close correlation between the magnetic fundamental properties and the topology of our spin systems. The NMR relaxometry profiles confirmed the nature of the physical mechanisms inducing the increase of nuclear relaxation rates at low (magnetic anisotropy) and high (Curie relaxation) magnetic fields. Moreover the transverse relaxivity (r₂) values for all the MNBs are higher than those of common contrast agents and the differences between the three MNBs are suggested to be due to the spin topology effect.

Highly dense linkage maps from 31 full-sibling families of turbot (Scophthalmus maximus) provide insights into recombination patterns and chromosome rearrangements throughout a newly refined genome assembly

Highly dense linkage maps enable positioning thousands of landmarks useful for anchoring the whole genome and for analysing genome properties. Turbot is the most important cultured flatfish worldwide and breeding programs in the fifth generation of selection are targeted to improve growth rate, obtain disease resistant broodstock and understand sex determination to control sex ratio. Using a Restriction-site Associated DNA approach, we genotyped 18,214 single nucleotide polymorphism in 1,268 turbot individuals from 31 full-sibling families. Individual linkage maps were combined to obtain a male, female and species consensus maps. The turbot consensus map contained 11,845 markers distributed across 22 linkage groups representing a total normalised length of 3,753.9 cM. The turbot genome was anchored to this map, and scaffolds representing 96% of the assembly were ordered and oriented to obtain the expected 22 megascaffolds according to its karyotype. Recombination rate was lower in males, especially around centromeres, and pairwise comparison of 44 individual maps suggested chromosome polymorphism at specific genomic regions. Genome comparison across flatfish provided new evidence on karyotype reorganisations occurring across the evolution of this fish group.

Metabolic and reproductive plasticity of core and marginal populations of the eurythermic saline water bug Sigara selecta (Hemiptera: Corixidae) in a climate change context

Ongoing climate change is driving dramatic range shifts in diverse taxa worldwide, and species responses to global change are likely to be determined largely by population responses at geographical range margins. Here we investigate the metabolic and reproductive plasticity in response to water temperature and salinity variation of two populations of the eurythermic saline water bug Sigara selecta: one population located close to the northern edge of its distribution, in a relatively cold, thermally stable region (SE England - 'marginal'), and one close to the range centre, in a warmer and more thermally variable Mediterranean climate (SE Spain - 'core'). We compared metabolic and oviposition rates and egg size, following exposure to one of four different combinations of temperature (15 and 25°C) and salinity (10 and 35gL^-1). Oviposition rate was significantly higher in the marginal population, although eggs laid were smaller overall. No significant differences in oxygen consumption rates were found between core and marginal populations, although the marginal population showed higher levels of plasticity in both metabolic and reproductive traits. Our results suggest that population-specific responses to environmental change are complex and may be mediated by differences in phenotypic plasticity. In S. selecta, the higher plasticity of the marginal population may facilitate both its persistence in current habitats and northward expansion with future climatic warming. The less plastic core population may be able to buffer current environmental variability with minor changes in metabolism and fecundity, but could be prone to extinction if temperature and salinity changes exceed physiological tolerance limits in the future.

The use of calcite mineral thermoluminescence for the determination of previously received gamma radiation dose in foodstuffs/E1 uso de la termoluminiscencia de la calcita para la determinación de la dosis de radiación gamma de alimentos previamente irradiados

This paper describes the potential use of calcite mineral dust as a high-dose radiation dosemeter. The results obtained show that saturation dose in natural calcite is of the order of 7 kGy. Measurements of absorbed dose, for samples previously irradiated with known gamma doses, showed a good level of agreement between actual doses and calculated doses, although the level of scatter is high.

Hematotoxicity of magnetite nanoparticles coated with polyethylene glycol: in vitro and in vivo studies

Hematotoxicity of magnetite nanoparticles with different coatings has been evaluated by determining their safety in vitro and in vivo in a rat model up to 30 days.

Overexpression of GYS1, MIF, and MYC is associated with adverse outcome and poor response to azacitidine in myelodysplastic syndromes and acute myeloid leukemia

BACKGROUND

The prognosis of myelodysplastic syndromes (MDS) and acute myeloid leukaemia (AML) is very heterogeneous.

PATIENTS AND METHODS

We analyzed the prognostic value of several genes in a cohort of 85 MDS and AML patients.

RESULTS

Overexpression of glycogen synthase 1 and macrophage migration inhibitory factor genes had an adverse outcome in multivariate analysis (P = .003 and P < .001, respectively). Furthermore, the higher expression of myelocytomatosis oncogene was associated with a lower response to azacitidine (P = .03).

CONCLUSION

In the current study we identified a specific gene expression profile as prognostic factors for response to azacitidine and survival in MDS and AML.

Observation of zero-point quantum fluctuations of a single-molecule magnet through the relaxation of its nuclear spin bath

A single-molecule magnet placed in a magnetic field perpendicular to its anisotropy axis can be truncated to an effective two-level system, with easily tunable energy splitting. The quantum coherence of the molecular spin is largely determined by the dynamics of the surrounding nuclear spin bath. Here we report the measurement of the nuclear spin-lattice relaxation rate 1/T1n in a single crystal of the single-molecule magnet Mn12-ac, at T ≈ 30 mK in perpendicular fields B⊥ up to 9 T. The relaxation channel at B ≈ 0 is dominated by incoherent quantum tunneling of the Mn12-ac spin S, aided by the nuclear bath itself. However for B⊥>5 T we observe an increase of 1/T1n by several orders of magnitude up to the highest field, despite the fact that the molecular spin is in its quantum mechanical ground state. This striking observation is a consequence of the zero-point quantum fluctuations of S, which allow it to mediate the transfer of energy from the excited nuclear spin bath to the crystal lattice at much higher rates. Our experiment highlights the importance of quantum fluctuations in the interaction between an "effective two-level system" and its surrounding spin bath.

Yessotoxin induces ER-stress followed by autophagic cell death in glioma cells mediated by mTOR and BNIP3

Yessotoxin at nanomolar concentrations can induce programmed cell death in different model systems. Paraptosis-like cell death induced by YTX in BC3H1 cells, which are insensitive to several caspase inhibitors,has also been reported. This makes yessotoxin of interest in the search of molecules that target cancer cells vulnerabilities when resistance to apoptosis is observed. To better understand the effect of this molecule at the molecular level on tumor cells, we conducted a transcriptomic analysis using 3 human glioma cell lines with different sensitivities to yessotoxin. We show that the toxin induces a deregulation of the lipid metabolism in glioma cells as a consequence of induction of endoplasmic reticulum stress. The endoplasmic reticulum stress in turn arrests the cell cycle and inhibits the protein synthesis. In the three cell lines used we show that YTX induces autophagy, which is involved in cell death. The sensibility of the cell lines used towards autophagic cell death was related to their doubling time, being the cell line with the lowest proliferation rate the most resistant.The involvement of mTOR and BNIP3 in the autophagy induction was also determined.

Water beetle tolerance to salinity and anionic composition and its relationship to habitat occupancy

Water salinity and ionic composition are among the main environmental variables that constrain the fundamental niches of aquatic species, and accordingly, physiological tolerance to these factors constitutes a crucial part of the evolution, ecology, and biogeography of these organisms. The present study experimentally estimated the fundamental saline and anionic niches of adults of two pairs of congeneric saline beetle species that differ in habitat preference (lotic and lentic) in order to test the habitat constraint hypothesis. Osmotic and anionic realised niches were also estimated based on the field occurrences of adult beetle species using Outlying Mean Index analysis and their relationship with experimental tolerances. In the laboratory, all of the studied species showed a threshold response to increased salinity, displaying high survival times when exposed to low and intermediate conductivity levels. These results suggest that these species are not strictly halophilic, but that they are able to regulate both hyperosmotically and hypoosmotically. Anionic water composition had a significant effect on salinity tolerance at conductivity levels near their upper tolerance limits, with decreased species survival at elevated sulphate concentrations. Species occupying lentic habitats demonstrated higher salinity tolerance than their lotic congeners in agreement with the habitat constraint hypothesis. As expected, realised salinity niches were narrower than fundamental niches and corresponded to conditions near the upper tolerance limits of the species. These species are uncommon on freshwater-low conductivity habitats despite the fact that these conditions might be physiologically suitable for the adult life stage. Other factors, such as biotic interactions, could prevent their establishment at low salinities. Differences in the realised anionic niches of congeneric species could be partially explained by the varying habitat availability in the study area. Combining the experimental estimation of fundamental niches with realised field data niche estimates is a powerful method for understanding the main factors constraining species' distribution at multiple scales, which is a key issue when predicting species' ability to cope with global change.

Complete genome analyses of G4P[6] rotavirus detected in Argentinean children with diarrhoea provides evidence of interspecies transmission from swine

Rotaviruses are dynamic pathogens that have been shown to infect multiple species. In 2006, two G4P[6] rotavirus strains with porcine characteristics were detected in Santa Fe, Argentina. To further characterize and determine the origin of these strains, nearly the full length of their genome was sequenced. While most of the genome segments were from porcine origin, the two strains grouped in different phylogenetic clusters in five out of the 11 genes, suggesting two independent interspecies transmission events. This study expands our knowledge of G4 rotavirus and reinforces the use of complete genome analyses as a key tool for diversity and evolution mechanicisms.

[Study of satisfaction of testicular prosthesis implantation in children]

Testicular absence may cause psychological trauma in children. It can be avoided by placing testicular prosthesis (TP). However there is no consensus on the optimal age of implantation. We evaluate the results of TP implantation and their complications, as well as patient and family satisfaction.

MATERIAL AND METHODS

This is a retrospective study of TP implanted between 2004-2010 in our center. Variables analyzed are: age, size and side, indication, surgical technique, complications and comorbidity. Telephone survey was done by a single interviewer to 50 families.

DATA COLLECTED

general family satisfaction, characteristics of the prosthesis (size, shape, location and consistency), body image and psychological situation of the child, duration of analgesia after surgery, reoperation rate, and family advice to other parents. Statistical analysis with SPSS-18.0.

RESULTS

107 prostheses were placed (4 bilateral, 64 left and 35 rights) at a mean age of 70,10 +/- 58,6 months. The most common indication was cryptorchidism (48.2%). Initial inguinal approach in 69%, and simultaneous contralateral orchidopexy in 29.9%. Only one patient refused the prostheses. In 71% the mother was interviewed. Parents consider size, shape and position appropriate in 55.6%, 66.7% and 82.22% respectively. Hard consistency of TP was considered in 82.3% of the patients. Psychological problems were absent in 86.7%. Nighty five percent would be willing to replace when it was necessary. Parents would recommend the intervention to parents in the same situation in 86.7%.

CONCLUSION

Testicular prosthesis avoids psychological trauma. The lack of satisfaction regarding to the small size and hardness makes necessary to replace the TP in adulthood. An open question remains whether we should consider the placement of TP in early ages, or if we should establish some indications based on a more rational communication with the family.

[Bronchoplastic surgery: tumorectomy in principal left bronchial tube in a 5-month old child]

INTRODUCTION

Resection of bronchial tumors usually needs resection of the lung parenchyma ventilated by the ill bronchus. Surgery over a developing child must preserve the biggest amount of lung parenchyma as possible. We show a complete resection of a benign tumor from the left main-stem bronchus, without pneumonectomy.

MATERIALS AND METHODS

Case report

RESULTS

A 5 month girl presented with left hypoventilation. No significant previous dates. After bronchoscopy (with negative biopsy), chest radiograph and CT, she was diagnosed of a tumor in the mainstem left bronchus (20 x 15 mm) without metastatic extension. A sleeve resection of the tumor, with carinal reconstruction was performed. It was done under unipulmonary ventilation, with selective bronchial intubation. The patient was extubated in the operating room and the hospital stay was of 5 days. Follow up bronchoscopies shows no anastomotic stricture neither leakage. The patient is doing well 2 years after surgery.

CONCLUSIONS

With this report and others in literature we can say that is possible to resect bronchial tumors in infancy without parenchymal resections.

Cannabidiol reduces lipopolysaccharide-induced vascular changes and inflammation in the mouse brain: an intravital microscopy study

BACKGROUND

The phytocannabinoid cannabidiol (CBD) exhibits antioxidant and antiinflammatory properties. The present study was designed to explore its effects in a mouse model of sepsis-related encephalitis by intravenous administration of lipopolysaccharide (LPS).

METHODS

Vascular responses of pial vessels were analyzed by intravital microscopy and inflammatory parameters measured by qRT-PCR.

RESULTS

CBD prevented LPS-induced arteriolar and venular vasodilation as well as leukocyte margination. In addition, CBD abolished LPS-induced increases in tumor necrosis factor-alpha and cyclooxygenase-2 expression as measured by quantitative real time PCR. The expression of the inducible-nitric oxide synthase was also reduced by CBD. Finally, preservation of Blood Brain Barrier integrity was also associated to the treatment with CBD.

CONCLUSIONS

These data highlight the antiinflammatory and vascular-stabilizing effects of CBD in endotoxic shock and suggest a possible beneficial effect of this natural cannabinoid.

Characterization of EST-derived microsatellites for gene mapping and evolutionary genomics in turbot

The detection of microsatellite sequences within expressed sequence tags (ESTs) connects potential markers with specific genes, generating type I markers. We have developed and mapped by linkage analysis a set of EST-derived microsatellites in the turbot, Scophthalmus maximus. One hundred and ninety-one microsatellites were identified from 9256 turbot ESTs. Primer design was possible with 98 microsatellites. After genotyping 25 wild turbot and the parents of two reference families for linkage analysis, 43 EST-derived microsatellites were selected because they met technical and polymorphism criteria. A final set of 31 EST-derived microsatellites could be mapped to 17 linkage groups of the turbot consensus map based on 242 anonymous microsatellites. Twenty-four microsatellite-containing ESTs were functionally annotated, confirming them as type I markers. Nineteen were mapped in the turbot consensus map. These EST-derived microsatellites constitute useful tools for genome scanning of turbot populations, marker-assisted selection programmes and comparative mapping.

Introducing guideline management in the healthcare information system architecture

This paper analyses different benefits of the full integration of components for clinical guideline management in the information system architecture of a healthcare organization. Subsequently, we propose a methodology for the development of these components based on the European prEN12967 standard, in order to facilitate this integration. Benefits are studied from several viewpoints. First, from the healthcare professional user viewpoint, as a powerful decision support tool, by which the Electronic Health Record of a specific patient could suggest the appropriate guidelines to apply and a particular assistance plan for him or her. We are centered in co-morbidity patients because these tasks are especially difficult to accomplish in this kind of patients. Second, from the guideline creation viewpoint, we analyze how the tacit knowledge implicit in the healthcare information system could be the base for the explicit representation of knowledge in a guideline and the posterior validation of these guidelines. Our approach is in agreement with today's new paradigm for evidence-based medicine demanded by healthcare professionals. The proposed method for guideline management components development is compliant with CEN's prEN12967 European standard, and consequently follows ITU-T's ODP methodology.

[A case of ureteritis in Henoch-Shönlein purpura]

Henoch-Schönlein purpura (HSP) is a multisystemic disorder mainly affecting the skin, joints, gastrointestinal tract, and kidneys but sometime rare complications that have been reported include urologic manifestations. We report a case of a 63 year old man was admitted to the hospital because a neurologic abnormalities, gastrointestinal blood loss and acute renal failure. One year before HSP was dignosed by percutaneous renal biopsy. A few days later admission the temperature was 38 masculineC and urine cultures yielded Echerichia Coli. An angio-magnetic resonance of the abdomen showed a marked dilatation of the distal left ureter with a level inside. Therapy with corticosteroids improved a clinical features and the usual renal function was recovered.

Large quantum nonlinear dynamic susceptibility of single-molecule magnets

The nonlinear dynamical response of Mn12 single-molecule magnets is experimentally found to be very large, quite insensitive to the spin-lattice coupling constant, and displaying peaks reversed with respect to classical superparamagnets. It is shown that these features are caused by the strong field dependence of the relaxation rate due to the detuning of energy levels between which tunneling takes place. The nonlinear susceptibility technique, previously overlooked, is thus proposed as a privileged probe to ascertain the occurrence of quantum effects in mesoscopic magnetic systems.

Glutamate activates PP125(FAK) through AMPA/kainate receptors in Bergmann glia

Glial glutamate receptors are likely to play a role in plasticity, learning, and memory and in a number of neuropathologies. An enhanced glutamate-dependent tyrosine phosphorylation has been detected in such processes. Using primary cultures of chick Bergmann glia cells and chick cerebellar slices, we addressed whether glial glutamate receptors can activate the nonreceptor tyrosine kinase pp125 focal adhesion kinase (pp125(FAK)). A dose- and time-dependent tyrosine phosphorylation of pp125(FAK) was found in both preparations upon glutamate treatment. This effect was mediated through alpha-amino-3-hydroxy-5-methyl-4-isoaxazolepropionate (AMPA)/kainate (KA) receptors, as shown by its inhibition by the specific antagonists 2,3-dioxo-6-nitro-1,2,3,4-tetrahydrobenzo[f]quinoxaline-7- sulfonamide (NBQX) and 6,7-dinitroquinoxaline-2,3-dione (DNQX) and the lack of effect of metabotropic agonists. FAK tyrosine phosphorylation was dependent on phosphatidylinositol 3-kinase activity. As expected, an increase in pp125(FAK) catalytic activity was found upon glutamate treatment. Immunprecipitation experiments demonstrated that FAK associates with ionotropic glutamate receptors. Taken together, these results suggest a role for glial glutamate receptors in cytoskeletal rearrengments and focal adhesion contact formation and provide new insight into the signaling transactions elicited by this neurotransmitter in glial cells.

Distribution of hepatitis C virus infection in liver biopsies from children and adults with chronic hepatitis C

Chronic hepatitis C in children is characterized by milder forms of liver damage than those found in adults. Such a difference has been attributed to a low viral load in children that may lead to poor recognition of infected cells by the immune system. One approach that could be used to confirm this hypothesis may be to examine the number of infected hepatocytes in liver biopsies. Paraffin embedded liver biopsies from 21 children and 15 adults with chronic hepatitis C virus (HCV) infection (with a similar duration of the infection) were hybridized in situ and the percentage of infected hepatocytes was correlated with the histological activity index, alanine aminotransferase levels and HCV viraemia levels. Histological activity index and HCV viraemia levels were statistically higher (P < 0.05 and P < 0.01 respectively) in adults than in children, and the percentage of infected hepatocytes was higher in adults (11.0 +/- 19.7%) than in children (4.6 +/- 3.6%), although it did not reach statistical significance. Also, the percentage of infected hepatocytes correlated with HCV-RNA concentration in serum in both children (r = 0.683, P = 0.001) and adults (r = 0.768, P = 0.001). The results show that liver damage in children with chronic hepatitis C is not related to the extent of infection in the liver. This findings support the hypothesis of that liver injury in chronic HCV infection is mediated by the host immune response.

Clinical and histological outcome after hepatitis B e antigen to antibody seroconversion in children with chronic hepatitis B

Data regarding the outcome of children with chronic hepatitis B after seroconversion are scarce. We describe the long-term evolution of these patients. One hundred and three children with antibody against hepatitis B e antigen and normal alanine aminotransferase (ALT) levels were followed for 0.6 to 12.5 years (mean, 6.3 years). Paired liver biopsies (before and after seroconversion) were available in 83 cases. Final biopsies were obtained 0.5 to 12.5 years (mean, 4.5 years) after seroconversion. ALT levels remained normal in most of the children (79%) throughout the follow-up. All children, except five who lost hepatitis B surface antigen, had serum viral DNA detected by polymerase chain reaction. When comparing baseline and final liver biopsies, a significant improvement (P <.001) was found in the histological activity index and in the necrosis, cytolysis, inflammation, and fibrosis scores. The histological diagnosis improvement in the final biopsy was significantly related (P <.001) to the time from seroconversion to the biopsy performance. All children had viral DNA on their final liver biopsy. In summary, seroconversion and ALT normalization are quite stable findings in children, and no differences in the long-term outcome between treated and untreated children were found. In light of the histological outcome, it seems unnecessary to perform a follow-up liver biopsy in these cases.

AZT treatment induces molecular and ultrastructural oxidative damage to muscle mitochondria. Prevention by antioxidant vitamins

AIDS patients who receive zidovudine (AZT) frequently suffer from myopathy. This has been attributed to mitochondrial (mt) damage, and specifically to the loss of mtDNA. This study examines whether AZT causes oxidative damage to DNA in patients and to skeletal muscle mitochondria in mice, and whether this damage may be prevented by supranutritional doses of antioxidant vitamins. Asymptomatic HIV-infected patients treated with AZT have a higher urinary excretion (355+/-100 pmol/kg/d) of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxo-dG) (a marker of oxidative damage to DNA) than untreated controls (asymptomatic HIV-infected patients) (182+/-29 pmol/kg/d). This was prevented (110+/-79 pmol/kg/d) by simultaneous oral treatment with AZT plus antioxidant vitamins (C and E). Mice treated with AZT also had a significantly higher urinary excretion of 8-oxo-dG than controls. Skeletal muscle mtDNA of mice treated with AZT had more 8-oxo-dG than controls. mt lipoperoxidation was also increased and skeletal muscle glutathione was oxidized. These effects may be due to an increased peroxide production by muscle mitochondria of AZT-treated animals. Dietary supplements with vitamins C and E at supranutritional doses protect against oxidative damage to skeletal muscle mitochondria caused by AZT.

A Ginkgo biloba extract (EGb 761) prevents mitochondrial aging by protecting against oxidative stress

The effect of aging on indices of oxidative damage in rat mitochondria and the protective effect of the Ginkgo biloba extract EGb 761 was investigated. Mitochondrial DNA from brain and liver of old rats exhibited oxidative damage that is significantly higher than that from young rats. Mitochondrial glutathione is also more oxidized in old than in young rats. Peroxide formation in mitochondria from old animals was higher than in those from young ones. According to morphological parameters (size and complexity), there are two populations of mitochondria. One is composed of large, highly complex mitochondria, and the other population is smaller and less complex. Brain and liver from old animals had a higher proportion of the large, highly complex mitochondria than seen in organs from young animals. Treatment with the Ginkgo biloba extract EGb 761 partially prevented these morphological changes as well as the indices of oxidative damage observed in brain and liver mitochondria from old animals.

[Observer agreement in the measurement of leg length]

The lower limb length measurement is an important element for the diagnosis of mechanical or structural lumbar pain. Also it has been used for referral pain associated with hip or knee osteoarthritis or the groin and suprapubic areas. The aims of the present study were: 1) to measure the intra and inter observers variation; 2) to measure the intra-method variation using two different techniques for lower limb length measurement, one called the "apparent measure" (9) and comparing both with the radiological measurement technique. Two medical doctors, training on the techniques for lower limb measurement, performed the measurements. The exclusion criteria were flexion deformity of the hip or an overweight greater than 20% over the mean weight expected according to age and sex. A correlation coefficient and its 95% confidence interval (CI) were estimated, one tail test (Ho: r = 0.75). Seventeen patients fulfilled the inclusion criteria, 15 females and two males. The mean age was 35.8 years +/- 13.0 (SD). The correlation coefficient for the inter-observers variation using the "apparent measure" was 0.99 (CI = 0.985) and for the difference between legs it was 0.88 (CI = 0.10). The inter-observers variation for lower limb length measurement using the technique of "real measure" showed a correlation coefficient of 0.77 (CI = 0.95) and for the difference in length between legs it was 0.99 (CI = 0.85). The intra-observer correlation coefficient was 0.95 (CI = 0.85). The correlation coefficient for the inter-observer using the X-ray pictures was 0.98 (CI = 0.92).(ABSTRACT TRUNCATED AT 250 WORDS)

[Effect of sub-pressor doses of dopamine on renin secretion in the anesthetized dog]

The effects of dopamine, its precursor L-dopa, and the dopaminergic agonist bromocriptine (BEC), on plasma renin activity (PRA), in pentobarbital anesthetized male dogs were investigated. Infusion of dopamine at a dose which did not change blood pressure ( 4 ug/kg/min) had no effect on the secretion of renin, nor did it produce modifications in the PRA response to furosemide (10 mg i.v.). L-dopa, in single dose of 500 mg (p.o), significantly augmented PRA two hours after administration, and the renin values remained elevated throughout the observation period of 120 minutes. However, BEC (2.5 mg p.o.) produced no changes in PRA during this time period. We conclude that at the dose utilized, dopamine apparently has no influence on the secretion of renin, and does not modify the increase in PRA provoked by diuretic. It is possible that the L-dopa induced augmentation in PRA is due to stimulation of the juxtaglomerular cells, by the noradrenaline formed in peripheral tissues from administered L-dopa.

[The renin angiotensin system in the pathology of arterial hypertension of aortic coarctation]

Nine patients with aortic coarctation were studied. On the fourth day of a low diet, blood samples were obtained for plasma renin activity (PRA) at 8:00 A.M., 11:00 A.M. and 5:00 P.M. On the same day a 24 hour urinary collection was obtained for the determination of aldosterone excretion. The following day 60 mg. of furosemide were given orally at 8:00 A.M. and another blood sample was drawn at noon. This study protocol was done before and after surgical correction of the aortic lesion. Mean systolic and diastolic blood pressure decreased significantly (P less than 0.005), while mean PRA and urinary aldosterone values showed no significant modifications after surgery. With these results, it is concluded that the renin-angiotensin-aldosterone system, does not seem to play a role in the chronic hypertension of the coarctation of the aorta. However, tests with angiotensin II specific blockers have to be performed before a definite conclusion can be drawn on this point.