Prophylaxis with resin in wood ants

Animals may use plant compounds to defend themselves against parasites. Wood ants, Formica paralugubris, incorporate pieces of solidified conifer resin into their nests. This behaviour inhibits the growth of bacteria and fungi in nest material and protects the ants against some detrimental microorganisms. Here, we studied the resin-collecting behaviour of ants under field and laboratory conditions. First, we focused on an important assumption of the self-medication hypothesis, which is that the animals deliberately choose the active plant material. In field cafeteria tests, the ants indeed showed a strong preference for resin over twigs and stones, which are building materials commonly encountered in their environment. We detected seasonal variation in the choice of ants: the preference for resin over twigs was more pronounced in spring than in summer, whereas in autumn the ants collected twigs and resin at equal rates. Second, we found almost similar seasonal patterns when comparing the collecting rates of pieces of wood that had been impregnated with turpentine (a distillate of oleoresin) and untreated pieces of wood, which reveals that the preference for resin is based on odour cues. Third, we tested whether the collection of resin is prophylactic or therapeutic. We found that the relative collection rate of resin versus stones did not depend on an experimental infection with the entomopathogenic fungus Metarhizium anisopliae in laboratory colonies. Together, these results show that the ants deliberately choose the resin and suggest that resin collection is prophylactic rather than therapeutic.

Insuffisance rénale terminale d'origine lithiasique : fréquence, causes et prévention [Nephrolithiasis-induced ESRD: frequency, causes and prevention].

Nephrolithiasis still remains a too frequent - and under-appreciated - cause of end-stage renal disease (ESRD), and this is all the most unfortunate since such an untoward course is now preventable in most cases. Among 1391 patients who started maintenance dialysis at Necker hospital between 1989 and 2000, nephrolithiasis was identified as the cause of ESRD in 45 of them, an overall prevalence of 3.2%. Infection stones accounted for 42.2% of cases, calcium stones for 26.7%, uric acid stones for 17.8% and hereditary diseases for 13.3%. The proportion of nephrolithiasis-associated ESRD declined from 4.7% to 2.2% from the 1989-1991 to the 1998-2000 period, as a result of the decreased incidence of ESRD in patients with infection and calcium nephrolithiasis. Based on our observations and on published reports, it emerges that most cases of nephrolithiasis-associated ESRD were due to sub-optimal management (especially in the case of infection or cystine stones) or to late (or erroneous) etiologic diagnosis, precluding early institution of appropriate therapeutic measures. In particular, several patients with primary hyperoxaluria or 2,8-dihydroxyadeninuria were diagnosed while already on dialysis or after unsuccessful kidney transplantation, due to wrong initial diagnosis. In conclusion, thanks to recent advances in diagnosis and management of stone formers, ESRD should now be prevented in the great majority of patients, at the condition of early etiologic diagnosis based on accurate morphoconstitutional analysis of calculi and metabolic evaluation, and early implementation of appropriate preventive medical treatment.

Lithiase cystinique [Cysteine lithiasis].

Cystinuria is a common inherited amino-aciduria resulting in abnormal urinary excretion of cystine and the dibasic aminoacids, lysine, arginine and ornithine. Formation of cystine kidney stones, recurrent infections and subsequent renal failure are the main complications of the disease. Recently, the gene SLC3A1 and SLC7A9, encoding the two subunits rBAT et b0,+AT of the proximal renal transporter complex, have been identified. In this article, we report the medical history of a 30-year-old patient and discuss the recent molecular progress, the clinical evolution, and the medical treatment of the cystinuria.

The role of C-Jun N-terminal kinase in a mouse model of intracerebral hemorrhage

Background: Intracerebral hemorrhage (ICH) is a subtype of stroke characterized by a haematoma within the brain parenchyma resulting from blood vessel rupture and with a poor outcome. In ICH, the blood entry into the brain triggers toxicity resulting in a substantial loss of neurons and an inflammatory response. At the same time, blood-brain barrier (BBB) disruption increases water content (edema) leading to growing intracranial pressure, which in turn worsens neurological outcome. Although the clinical presentation is similar in ischemic and hemorrhagic stroke, the treatment is different and the stroke type needs to be determined beforehand by imaging which delays the therapy. C-Jun N-terminal kinases (JNKs) are a family of kinases activated in response to stress stimuli and involved in several pathways such as apoptosis. Specific inhibition of JNK by a TAT-coupled peptide (XG-102) mediates strong neuroprotection in several models of ischemic stroke in rodents. Recently, we have observed that the JNK pathway is also activated in a mouse model of ICH, raising the question of the efficacy of XG-102 in this model. Method: ICH was induced in the mouse by intrastriatal injection of bacterial collagenase (0,1 U). Three hours after surgery, animals received an intravenous injection of 100 mg/kg of XG-102. The neurological outcome was assessed everyday until sacrifice using a score (from 0 to 9) based on 3 behavioral tests performed daily until sacrifice. Then, mice were sacrificed at 6 h, 24 h, 48 h, and 5d after ICH and histological studies performed. Results: The first 24 h after surgery are critical in our ICH mice model, and we have observed that XG-102 significantly improves neurological outcome at this time point (mean score: 1,8 + 1.4 for treated group versus 3,4+ 1.8 for control group, P<0.01). Analysis of the lesion volume revealed a significant decrease of the lesion area in the treated group at 48h (29+ 11mm3 in the treated group versus 39+ 5mm3 in the control group, P=0.04). XG-102 mainly inhibits the edema component of the lesion. Indeed, a significant inhibition Journal of Cerebral Blood Flow & Metabolism (2009) 29, S490-S493 & 2009 ISCBFM All rights reserved 0271-678X/09 $32.00 www.jcbfm.com of the brain swelling was observed in treated animals at 48h (14%+ 13% versus 26+ 9% in the control group, P=0.04) and 5d (_0.3%+ 4.5%versus 5.1+ 3.6%in the control group, P=0.01). Conclusions: Inhibition of the JNK pathway by XG- 102 appears to lead to several beneficial effects. We can show here a significant inhibition of the cerebral edema in the ICH model providing a further beneficial effect of the XG-102 treatment, in addition to the neuroprotection previously described in the ischemic model. This result is of interest because currently, clinical treatment for brain edema is limited. Importantly, the beneficial effects observed with XG-102 in models of both stroke types open the possibility to rapidly treat stroke patients before identifying the stroke subtype by imaging. This will save time which is precious for stroke outcome.

Dialyse et écologie: est-il possible de faire mieux à l'avenir [Dialysis and ecology: can we do better in the future?].

Development of dialysis has saved the lives of many patients. However, haemodialysis and peritoneal dialysis are very demanding in resources such as water and electricity, and generate a large amount of waste. In this article, we will review the environmental aspects of dialysis. Different solutions will be discussed, such as recycling of water discharged during reverse osmosis, the integration of solar energy, recycling of waste plastics, and the use of other techniques such as sorbent dialysis. In a world where natural resources are precious and where global warming is a major problem, it is important that not only dialysis, but all branches of medicine become more attentive to ecology.

Enseignement de recommandations pour la pratique: la prévention et le dépistage [Teaching practice recommendations: prevention and screening].

The aim of this article is to provide guidance to family doctors on how to tutor students about effective screening and primary prevention. Family doctors know their patients and adapt national and international guidelines to their specific context, risk profile, sex and age as well as to the prevalence of the disorders under consideration. Three cases are presented to illustrate guideline use according to the level of evidence (for a 19-year-old man, a 60-year-old woman, and an 80-year-old man). A particular strength of family medicine is that doctors see their patients over the years. Thus they can progressively go through the various prevention strategies, screening, counselling and immunisation, accompanying their patients with precious advice for their health throughout their lifetime.

Water Quality Water Advocacy, September 14, 2007

Iowa’s surface and ground water serves as a precious resource for industries, businesses and communities and provides state citizens and visitors with invaluable cultural and recreational opportunities. While water quality is regulated by the Iowa Department of Natural Resources (IDNR), compliance assistance is available through the Iowa Department of Economic Development (IDED) Water Quality Advocacy Program.

Evaluación poblacional de Chondracanthus chamissoi (C. Agardh 1820) en las bahías de Pisco y Paracas, Otoño 2010.

Entre mayo y junio 2010, se desarrolló la evaluación poblacional de la macroalga Chondracanthus chamissoi “yuyo” de las praderas en las bahías de Pisco y Paracas. Las biomasas medias fluctuaron entre 2,2 y 67,0 g.m-2, con promedio de 43,6 g.m-2. Se estimó una biomasa total de 211,96 toneladas (±56,8%); de los cuales 179,74 t correspondieron a Atenas; 30,1 t a Puerto Nuevo y 2,1 t a Playa Lobería. El sustrato de fijación estuvo compuesto, principalmente, por piedras, conchuela y arena media. En las praderas de Atenas ocupó la mayor parte del área evaluada, en las praderas de Puerto Nuevo y Playa Lobería se encontraron reducidas, respecto al 2007. Se encontró ejemplares entre 1 y 25 cm de longitud. El peso total individual varió de 0,1 a 94,6 g. Se registró biodiversidad asociada conformada por moluscos. Las condiciones oceanográficas se registraron normales, lo que permite suponer que la disminución poblacional respondería a las actividades de extracción.

PTH and 1.25 vitamin D response to a low-calcium diet is associated with bone mineral density in renal stone formers.

BACKGROUND: Renal calcium stones and hypercalciuria are associated with a reduced bone mineral density (BMD). Therefore, the effect of changes in calcium homeostasis is of interest for both stones and bones. We hypothesized that the response of calciuria, parathyroid hormone (PTH) and 1.25 vitamin D to changes in dietary calcium might be related to BMD. METHODS: A single-centre prospective interventional study of 94 hyper- and non-hypercalciuric calcium stone formers consecutively retrieved from our stone clinic. The patients were investigated on a free-choice diet, a low-calcium diet, while fasting and after an oral calcium load. Patient groups were defined according to lumbar BMD (z-score) obtained by dual X-ray absorptiometry (group 1: z-score <-0.5, n = 30; group 2: z-score -0.5-0.5, n = 36; group 3: z-score >0.5, n = 28). The effect of the dietary interventions on calciuria, 1.25 vitamin D and PTH in relation to BMD was measured. RESULTS: An inverse relationship between BMD and calciuria was observed on all four calcium intakes (P = 0.009). On a free-choice diet, 1.25 vitamin D and PTH levels were identical in the three patient groups. However, the relative responses of 1.25 vitamin D and PTH to the low-calcium diet were opposite in the three groups with the highest increase of 1.25 vitamin D in group 1 and the lowest in group 3, whereas PTH increase was most pronounced in group 3 and least in group 1. CONCLUSION: Calcium stone formers with a low lumbar BMD exhibit a blunted response of PTH release and an apparently overshooting production of 1.25 vitamin D following a low-calcium diet.

Lithiases d'infection [Infective lithiasis].

We report the case of a 69-year-old woman, with a BMI of 42.9, suffering from bilateral struvite calculi and who raised end stage renal failure. Urease-synthesizing bacteria, leading to the hydrolysis of urea into ammonium and to an alkaline urine (pH > 7.2), are required for struvite stone formation in humans. Struvite component constitutes the majority of staghom calculi. Patients with struvite stones could lose renal function because of obstructive or pyelonephritic episodes and surgical interventions on the kidney. Therapeutic success needs a follow up by a specialized uro-nephrologist team as soon as possible.

Moyens de défense des bactéries.

Fifty years ago, the introduction of penicillin, followed by many other antibacterial agents, represented an often underestimated medical revolution. Indeed, until that time, bacterial infections were the prime cause of mortality, especially in children and elderly patients. The discovery of numerous new substances and their development on an industrial scale confronted us with the illusion that bacterial infections were all but vanquished. However, the widespread and sometimes uncontrolled usage of these agents has led to the selection of bacteria resistant to practically all available antibiotics. Bacteria utilize three main resistance strategies: (i) decrease in drug accumulation, (ii) modification of target, and (iii) modification of the antibiotic. Bacteria can decrease drug accumulation either by becoming impermeable to antibiotics, or by actively excreting the drug accumulated in the cell. As an alternative, they can modify the structure of the antibiotic's molecular target--usually an essential metabolic enzyme of the bacteria--and thus escape the drug's toxic effect. Lastly, they can produce enzymes capable of modifying and directly inactivating the antibiotics. In addition, bacteria have evolved extremely efficient genetic transfer systems capable of exchanging and accumulating resistance genes. Some pathogens, such as methicillin-resistant Staphylococcus aureus and enterococci are now resistant to almost all available antibiotics. Vancomycin is the only non-experimental drug left to treat severe infections due to such organisms. However, vancomycin resistance has already appeared several years ago in enterococci, and was also recently described in staphylococci, in Japan, France and the United-States. Antibiotics are precious drugs which must be administered to patients who need them. On the other hand, the development of resistance must be kept under control by a better comprehension of its mechanisms and modes of transmission and by abiding by the fundamental rules of anti-infectious chemotherapy, i.e.: (i) choose the most efficient antibiotic according to clinical and local epidemiological data, (ii) target the bacteria according to the microbiological data at hand, and (iii) administer the antibiotic at an adequate dose which will leave the pathogen no chance to develop any resistance.

ESRD caused by nephrolithiasis: prevalence, mechanisms, and prevention.

BACKGROUND: The contribution of nephrolithiasis-related end-stage renal disease (ESRD) to patients requiring renal replacement therapy has never been specifically evaluated. METHODS: Of the entire cohort of 1,391 consecutive patients who started maintenance dialysis therapy at our nephrology department between January 1989 and December 2000, a total of 45 patients (21 men) had renal stone disease as the cause of ESRD and constitute the study material. Type and cause of renal stone disease was determined in the 45 patients, as well as the change in prevalence of nephrolithiasis-related ESRD with time during this 12-year period. RESULTS: The overall proportion of nephrolithiasis-related ESRD was 3.2%. Infection (struvite) stones accounted for 42.2%; calcium stones, 26.7%; uric acid nephrolithiasis, 17.8%; and hereditary diseases (including primary hyperoxaluria type 1 and cystinuria), 13.3% of cases. Women were predominant among patients with infection and calcium stones, whereas men were predominant among patients with uric acid or hereditary stone disease. The proportion of patients with nephrolithiasis-related ESRD decreased from 4.7% in the triennial period 1989 to 1991 to 2.2% in the most recent period, 1998 to 2000 ( P = 0.07). This tendency to a decreasing prevalence mainly was caused by a rarefaction of infection and calcium stones with time, whereas frequencies of uric acid and hereditary stone disease remained essentially unchanged. CONCLUSION: Severe forms of nephrolithiasis remain an underestimated cause of potentially avoidable ESRD and need for renal replacement therapy. These findings highlight the crucial importance of accurate stone analysis and metabolic evaluation to provide early diagnosis and proper therapy for conditions that may lead to ESRD through recurrent stone formation and/or parenchymal crystal infiltration.

Evaluation of Cohesion and Swell Characteristics of Asphalt Treated Base Mixtures, R-223, 1968

This study was undertaken to evaluate the suitability of various stones which play an important role in the properties of compacted mixtures in asphalt treated bases. The determination of the effect of water temperature on the cohesion of the mixes is investigated. A number of stones were prepared for the test. Attention is paid to the particular source of stone with the corresponding test results. A preliminary study of the effect of lime when added to mixed aggregate was also conducted. The purpose of this study is to provide needed information on the cohesive characteristics of asphalt treated bases using a wide range of stones. This study is also to evaluate the suitability of the various stone sources.

El treball cooperatiu com a mètode d'experimentació en l'art : treballar l'educació artística a l'educació infantil

Els objectius de l’estudi realitzat en aquest treball són: comprovar que l’educació artística també pot ser una eina d’inclusió a l’escola, conèixer els beneficis de l’experimentació/exploració en l’art, i observar com aquests influeixen en l’aprenentatge dels infants, i finalment veure els beneficis del treball cooperatiu com a mètode d’experimentació en l’art. L’estudi s’ha realitzat a partir d’ una recerca teòrica i duent a terme una part pràctica de vàries sessions amb la col·laboració dels infants de P4 de l’escola Joan XXIII d’Hostalets de Balenyà. La pràctica s’ha anomenat “Art amb pedres”, que com el seu nom indica, les pedres eren l’element natural que han utilitzat els infants per a convertir-se en verdaders artistes!