Antiviral Activity of Ribosome-Inactivating Proteins

Ribosome-inactivating proteins (RIPs) are rRNA N-glycosylases from plants (EC 3.2.2.22) that inactivate ribosomes thus inhibiting protein synthesis. The antiviral properties of RIPs have been investigated for more than four decades. However, interest in these proteins is rising due to the emergence of infectious diseases caused by new viruses and the difficulty in treating viral infections. On the other hand, there is a growing need to control crop diseases without resorting to the use of phytosanitary products which are very harmful to the environment and in this respect, RIPs have been shown as a promising tool that can be used to obtain transgenic plants resistant to viruses. The way in which RIPs exert their antiviral effect continues to be the subject of intense research and several mechanisms of action have been proposed. The purpose of this review is to examine the research studies that deal with this matter, placing special emphasis on the most recent findings.     

First Case of Highly Pathogenic Avian Influenza in Poultry in Spain

In October 2009, highly pathogenic avian influenza virus (HPAIV) was isolated for the first time in poultry in Spain. Sequencing analysis revealed that it was an H7N7 HPAIV. The progenitors of H7 HPAIV strains involved in recent European poultry outbreaks were simultaneously circulating in wild birds. The infected Spanish farm is located close to a reservoir abundant in wild birds. Epidemiological investigation found no links to other poultry holdings and those located in the control area were negative for AIV. Previous spatial risk analyses had identified the area where the infected holding is located to beat high relative risk for the introduction and presence of H5N1 HPAIV by wild birds. We suggest a risk‐based surveillance scheme that targets smaller geographical units but maintains the number of wild birds being sampled, as early detection of potentially pathogenic AIV is crucial in preventing spread to poultry.     

Evaluation of the anticonvulsant and muscle relaxant effects of the methanol root bark extracts of Annona senegalensis

ObjectiveTo investigate the potentials of the root bark of Annona (A.) senegalensis in the control of seizure and related hypnotic and motor incoordination effects in mice using experimental models.MethodsThe methanol extract (ME) of the root bark of A. senegalensis was studied in mice using pentylenetetrazole (PTZ) induced convulsions, phenobarbitone induced sleeping time and motor coordination test on rota-rod performance. Acute toxicity and lethality (LD₅₀) test as well as phytochemical analysis were also carried out.ResultsThe extract (200, 400, 800 mg/kg) exhibited a non-dose dependent significant (P <0.05) delay in the onset of both tonic and clonic phases of seizure induced by PTZ (60 mg/kg, s.c.) as well as offered a 100% protection (200 mg/kg) in mice from PTZ induced seizures. The extract significantly (P <0.05) decreased the latency and increased the duration of phenobarbitone induced sleeping time. At 200 mg/kg, the extract exhibited a significant (P <0.05) motor incoordination. The acute toxicity test revealed an oral LD₅₀ of 1 296 mg/kg, while the phytochemical studies showed the presence of alkaloids, resins, glycosides, carbohydrate, reducing sugar, flavonoids, terpenoids, saponins and tannins.ConclusionThe extract of A. senegalensis possessed anticonvulsant activity with pronounced hypnotic and muscle relaxant effects.     

Left ventricular mass index and sports: the influence of different sports activities and arterial blood pressure

BACKGROUND: The mechanisms by which endurance training produces physiological hypertrophy have been thoroughly investigated but not with young athletes. The aim of our study was to investigate arterial blood pressure exercise responses in young athletes who started heavy training by the age of 11, participating in metabolically different sports (cycling, kayaking, and soccer) and to analyse the influence that arterial blood pressure at maximum exercise and VO(2) max could have on the development of cardiac mass in these subjects. SUBJECTS AND METHODS: We studied a group of well trained normotensive male subjects, comprising 37 cyclists, 15 soccer players and 12 canoeists (mean age, 16+/-1 years). Evaluation included a clinical history and physical examination, M-mode and two-dimensional echocardiography, 12-lead resting electrocardiogram and a graded exercise test with direct determination of VO(2) max. Systolic and diastolic blood pressure were measured at rest and maximum exercise. Determination of the left ventricular mass index (LVMI) was performed using Devereux's formula with correction for the body surface area. RESULTS: Cyclists showed values of LVMI in g m(-2) significantly higher than those of other subjects (123 vs. 92 and 113). Canoeists showed the maximal arterial blood pressure at maximum exercise in mmHg (190 vs. 172 and 170) and cyclists showed the maximal VO(2) ml kg(-1) min(-1) uptake (57.6 vs. 48.5 and 53.3). A linear correlation was found between LVMI and VO(2) max (r=0.4727, P<0.001) and this correlation was also significant with systolic blood pressure at maximum exercise (r=0.2909, P<0.01). No differences in LVMI were found when comparing those subjects who presented systolic blood pressure at maximum exercise equal or greater than 195 mmHg with those who presented less than this value. CONCLUSIONS: It can be concluded that VO(2) max is the variable that better correlates with the LVMI. Athletes who reach greater systolic blood pressures at peak exercise have a tendency to develop greater LVMI. In comparison with soccer players and canoeists, cyclists are the sportsmen who develop a greater LVMI and VO(2) max.     

Incidence and risk factors for childhood brain tumors in the ILE DE France

A case-control study investigating risk factors for childhood brain tumors was conducted in the lle de France (Paris region). During a 2-year period (1985–1987) 109 newly diagnosed cases were identified and, of these, 75 could be interviewed. In the same region, 113 population controls, frequency-matched for year of birth, were interviewed. Odds ratios adjusted for child's age and sex and for maternal age were estimated for each risk factor present in utero or during childhood by conditional logistic regression. Statistically significant associations were found for the following risk factors: farm residence, cat scratches, home treated with pesticides, passive smoking, family history of cancer, antihistamine intake. Intake of vitamin supplements during childhood was associated with a decrease in risk. This study is part of a multicentric case-control study coordinated by the International Agency for Research on Cancer and its results will be compared for consistency, and pooled with those of other centers using the same protocol.