The unknown third - Hydrogen isotopes in tree-ring cellulose across Europe.

This is the first Europe-wide comprehensive assessment of the climatological and physiological information recorded by hydrogen isotope ratios in tree-ring cellulose (δ2Hc) based on a unique collection of annually resolved 100-year tree-ring records of two genera (Pinus and Quercus) from 17 sites (36°N to 68°N). We observed that the high-frequency climate signals in the δ2Hc chronologies were weaker than those recorded in carbon (δ13Cc) and oxygen isotope signals (δ18Oc) but similar to the tree-ring width ones (TRW). The δ2Hc climate signal strength varied across the continent and was stronger and more consistent for Pinus than for Quercus. For both genera, years with extremely dry summer conditions caused a significant 2H-enrichment in tree-ring cellulose. The δ2Hc inter-annual variability was strongly site-specific, as a result of the imprinting of climate and hydrology, but also physiological mechanisms and tree growth. To differentiate between environmental and physiological signals in δ2Hc, we investigated its relationships with δ18Oc and TRW. We found significant negative relationships between δ2Hc and TRW (7 sites), and positive ones between δ2Hc and δ18Oc (10 sites). The strength of these relationships was nonlinearly related to temperature and precipitation. Mechanistic δ2Hc models performed well for both genera at continental scale simulating average values, but they failed on capturing year-to-year δ2Hc variations. Our results suggest that the information recorded by δ2Hc is significantly different from that of δ18Oc, and has a stronger physiological component independent from climate, possibly related to the use of carbohydrate reserves for growth. Advancements in the understanding of 2H-fractionations and their relationships with climate, physiology, and species-specific traits are needed to improve the modelling and interpretation accuracy of δ2Hc. Such advancements could lead to new insights into trees' carbon allocation mechanisms, and responses to abiotic and biotic stress conditions.

Functional xylem anatomy of aspen exhibits greater change due to insect defoliation than to drought.

The study of tree rings can reveal long-term records of a tree's response to the environment. This dendroecological approach, when supplemented with finer-scale observations of the xylem anatomy, can provide novel information about a tree's year-to-year anatomical and hydraulic adjustments. Here we use this method in aspen (Populus tremuloides Michx.) to identify xylem response to drought and insect defoliation. Surprisingly, we found that precipitation influenced vessel diameter mostly in the trees' youth, while this correlation was less pronounced at maturity. This is likely due to a reduction in stress the stand experiences as it ages, and reflects an ability to mediate drought stress as trees mature. Defoliation events caused consistent and profound changes in fiber anatomy likely leading to reduced structural support to vessels. We therefore expect that in years of defoliation trees may be vulnerable to drought-induced cavitation when leaf area recovers. This study highlights how the inclusion of cellular level measurements in tree ring studies provides additional information on how stress events may alter tree functioning through alterations in structure.

[Clinical management of homocystinuria: case report and review of the literature]. / Homocistinuria; curso clínico y tratamiento dietético: a propósito de dos casos.

Homocystinuria is a congenital disorder of methyonine metabolism that leads to increased plasmatic, urinary and tissue deposits of methyonine and its main metabolite: homocysteine. Homocysteine deposits are toxic for the skeletal system (osteoporosis), the eyes (lens dislocation), central nervous system (seizures, psychiatric disorders) and also induce vascular damage (stroke and other cardiovascular events). This article reports two patients with homocystinuria in two siblings, followed by a concise review on the therapeutic strategies available for this disorder.

[Five-year comparison of two techniques of bariatric surgery in patients with morbid obesity followed up in a nurse consultation]. / Comparación a 5 años de dos técnicas de cirugía bariátrica en pacientes con obesidad mórbida seguidos en consulta enfermera.

AIMS: To compare the evolution of weight loss and complications in the patients subjected to two techniques of bariatric surgery (RVG: ring vertical gastroplasty and BP: gastric by pass type Capella) carried out in HospitalLa Paz during the years 2000 and 2001. MATERIAL AND METHODS: 51 patients (27 RVG and 24 BP) were operated, and 44 (22 RVG and 22 BP) completed the follow-up at 1 year, 43 (22 RVG and 21 BP) at 2 years, and 28 (10 RVG and 18 BP) at 5 years. The parameters analyzed at 6, 12, 18, 24 months and 5 years were BMI (body mass index), EI (effectiveness index), % LW (percentage of lost weight), % LEW (percentage of lost excess of weight), alimentary intolerances, digestive complications, surgical complications, physical activity and modification of alimentary habits. RESULTS: An important reduction of weight was observed at 6 months with both techniques (% LEW: 45.8% with RVG and 53.4% with BP). After 12 months the loss of weight was significantly higher with BP (% LEW at 2 years: 59.5% with RVG and 83% with BP). However, at 5 years a weight recovery was detected in both groups of patients. At 12 months the patients subjected to RVG tolerated worse the meat and at 18 months the group of BP tolerated worse the rice. There were not significant differences in other parameters. CONCLUSION: The long term results are better with BP than with RVG. There is a reduction of effectiveness at 5 years that could be related with the modification of alimentary habits and with giving up attendance to the nurse consultation.

[Postsurgical chylous ascites: case report and literature review]. / Tratamiento dietético de la ascitis quilosa postquirúrgica: caso clínico y revisión de la literatura.

Chylous ascites derives from chyle leakage into the peritoneal cavity, either due to rupture or obstruction of abdominal lymphatic vessels. The main clinical sign is abdominal distention, while diagnosis requires the presence of triglycerides in ascitic fluid. Neoplasms are the most common cause of chylous ascites, although less common causes, such as abdominal surgery, should also be considered. The mainstay of therapy is hyperproteic diet with fat restriction and middle-chain triglycerides. Parenteral nutrition is reserved for cases in which dietary treatment fails to restore an optimal nutritional status or is contraindicated, whereas surgery is considered for patients that are deemed refractory to conservative therapy. We present a case of chylous ascites secondary to retroperitoneal lymphadenectomy.

[Efficacy of inhaled zanamivir in the treatment and prevention of influenza]. / Eficacia del zanamivir inhalado para el tratamiento y la prevención de la gripe.

The aim of this work is to evaluate the efficacy of zanamivir in the treatment and prevention of influenza. This drug is a neuraminidase inhibitor that is effective against both A and B influenza viruses. Five randomized, double-blind, placebo-controlled, clinical trials have been published, showing a reduction in the duration of flu symptoms between 1 and 2.5 days. A greater benefit is seen in the patients with influenza-confirmed infection, with fever and when the treatment begins in the first 30-36 hours. For the prevention of influenza, two placebo-controlled clinical trials have been published, where flu incidence was reduced by 50-67%. The characteristics of zanamivir (efficacy, safety and lack of resistance) make it an appropriate option for subjects not protected by vaccination and for those with high risk of complications.