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Resume Des progres techniques considerables ont eu lieu dans les domaines hospitalier et medicosocial. Cependant, persistent des pratiques inappropriees sources d’effets indesirables et de violences. L’enjeu est de diminuer les risques, tout en protegeant ceux qui exercent. Le mot « maltraitance » a ete utile dans les annees 1990 pour faire connaitre ces derives ou negligences et inciter a leurs signalements et corrections. Aujourd’hui, ce terme peut porter tort aux professionnels et aux etablissements. Englobant tout, il est a l’origine d’une confusion entre les pratiques inappropriees individuelles, les carences organisationnelles et des violences qui relevent de la delinquance. Cette confusion banalise des delits et criminalise des actions inadaptees de professionnels ou d’organisations. Les liens evidents entre les pratiques professionnelles et les organisations sont frequemment meconnus. C’est la structure qui devrait adapter les competences, les effectifs et les locaux aux besoins des personnes a aider et a soigner. La maltraitance n’est pas qu’individuelle et le professionnel est souvent maltraitant malgre lui. Le risque est la desaffection de carrieres devenues deshumanisees et stigmatisantes. La priorite est d’inverser cette tendance. Ces metiers relationnels du soin et de l’aide aux plus vulnerables doivent redevenir valorisants et attractifs. La terminologie a un role. Une premiere mesure serait de depasser le mot global de maltraitance pour separer l’intention de nuire des actions inappropriees et separer aussi ce qui est organisationnel de ce qui est individuel. Des definitions basees sur les mecanismes et facteurs de risques seraient plus operationnelles pour aller vers des pratiques professionnelles et des organisations mieux adaptees aux besoins.

With aging worldwide population and the high incidence of cancer in the population of people over 75 years old, there is a need for oncologists and geriatricians to strengthen their collaboration to improve elderly patients care. Complexity of cancer and aging issues must be considered simultaneously to establish a personalized care plan. Thus, the G8 is a screening tool that allows to identify patients who should benefit from a geriatric assessment, which is a key step in the management process. This specific evaluation offers a multidisciplinary approach to functional, psychological, nutritional, cognitive and social status and has demonstrated its prognostic value in terms of choice of treatment but also in terms of patient survival. In nearly 20% of cases, the geriatric assessment leads to a change in the choice of treatment, and at one year the initial care plan is not carried out in a quarter of cases. The presence of malnutrition and functional impairment leading to dependence on basic activities of daily living had a significant impact on this change in therapeutic choice. Survival is not only impacted by malnutrition and functional impairment but also by the presence of severe comorbidities and thymic and neurocognitive impairment. The patient's choice must remain at the center of the elaboration of the care plan with the oncologists and geriatricians in order to propose the most appropriate treatment for his or her situation.

Urinary tract infections (UTI) are the second cause of community-acquired bacterial infections in the elderly. Distinguishing symptomatic UTI from asymptomatic bacteriuria is problematic, as older adults are less likely to present with localized urinary symptoms. We evaluated characteristics of patients presenting UTI among elderly with sepsis. Moreover, we aimed to evaluate the sensibility and specificity of urine dipstick tests in the diagnosis of UTI in geriatric population.We led a prospective, monocentric, observational study between April 2017 and January 2018. We included patients hospitalized in geriatric wards, who were prescribed urine culture for UTI symptoms or/and infection without primary sites for which a urine culture was prescribed. Dipstick urinalyses were performed for all patients. Clinical and biological characteristics of all patients were compared according to the final diagnosis of UTI. Moreover, results of dipstick tests were evaluated for the diagnosis of UTI in this population.Among 165 patients, 67 (40.6 %) had a UTI and 98 (59.4 %) had another diagnosis. These two groups were comparable for age and daily-living activities. In the UTI group, the proportion of women was higher than in the other group (P0.05), and mean MMSE score was lower (P0.05). Positive urine dipstick test for leukocytes and/or nitrites had high sensitivity (92 %), but low specificity (50 %). Negative predictive value of this test was high (91 %).For suspicion of UTI among elderly, few criteria are specific. Negative dipstick tests can suggest an absence of UTI due to its high negative predictive value.

Rats (brown- or Norway- and black: Rattus norvegicus and Rattus rattus , respectively) are very invasive rodents. They are originated from Southeast Asia and are present now everywhere in the world, exploiting their extraordinary capacity to proliferate in close contact with human populations. Rats, and particularly the brown rat, take advantage of conditions raised by overpopulation in cities, lack of hygiene and poverty. Beside the significant damage caused by their presence in rural and urban ecosystems, rats are also dangerous carriers of numerous pathogens transmissible to humans. Among these pathogens, leptospira and hantaviruses (particularly Seoul virus or SEOV) are the most important. Seoul virus belongs to the virus family Bunyaviridae and genus Hantavirus, has a worldwide distribution, and causes haemorrhagic fever with renal syndrome (HFRS) in humans. Leptospira and particularly Leptospira interrogans , serogroup Icterohaemorrhagiae, are zoonotic bacteria very frequently borne and excreted by rats and cause severe disease - leptospirosis - both in humans and domestic animals. Next-generation sequencing confirmed that rats can carry many other microbes and parasites for which the zoonotic capacity is not always determined. The importance of rats as pests and carriers of numerous pathogens demands the fight against their proliferation, especially in urban environments. The use of rodenticides such as anticoagulants is one pillar of prevention. However, increasing levels of rodenticide resistance can often render this means of control as ineffective. The second and absolutely necessary pillar of prevention involves the control of all environmental factors, which favour the establishment and proliferation of rats: age of housing, density of dwellings, defective drains/sewers, poor structural maintenance, proximity to food sources and poor hygiene.

High pressure promotes the formation of polyhydrides with unusually high hydrogen-to-metal ratios. These polyhydrides have complex hydrogenic sublattices. We synthesized iron pentahydride (FeH

Rift Valley Fever (RVF) is a zoonotic arbovirosis. Among animals, it mainly affects ruminants, causing abortions in gravid females and mortality among young animals. In humans, RVF virus infection is usually asymptomatic or characterized by a moderate fever. However, in 1 to 3% of cases, more severe forms of the disease (hepatitis, encephalitis, retinitis, hemorrhagic fever) can lead to the death of infected individuals or to major sequels. The RVF virus (Bunyaviridae, genus Phlebovirus) was identified for the first time in the 1930s in Kenya. It then spread over almost all African countries, sometimes causing major epizootics/epidemics. In 2000, the virus was carried out of Africa, in the Middle East Arabian Peninsula. In 2007-2008, Eastern-African countries, including Madagascar, reported significant episodes of RVF virus, this was also the case for the Comoros archipelago and the French island of Mayotte. This ability to spread associated with many vectors, including in Europe, and high viral loads in infected animals led the health authorities worldwide to warn about the potential emergence of RVF virus in areas with a temperate climate. The awareness has increased in recent years with climate changes, which may possibly modify the vector distribution and competence, and prompted many RVF virus-free countries to better prepare for a potential implantation of RVF.

The extent to which high-density lipoprotein (HDL) cholesterol levels can be increased in patients with low HDL cholesterol is important because low HDL cholesterol levels increase the risk of coronary heart disease (CHD). During the past 14 years, we have assessed risk factors in Turks, a population in which extremely low HDL cholesterol levels (mean 36 mg/dl in men, 42 mg/dl in women) are a prime CHD risk factor. Although genetically determined to a significant extent, these low HDL cholesterol levels can be modulated by lifestyle factors, as in other populations.'We measured the HDL cholesterol levels in men and women residing in Istanbul at 3 time points: 1990 to 1993, 1996 to 2000, and 2003. The mean HDL cholesterol levels increased from 45.3 +/- 9.5 mg/dl in 1990 to 1993 to 49.7 +/- 12 mg/dl in 2003 (p < 0.0001) in women, but were virtually unchanged in men (38 +/- 8 vs 39 +/- 10 mg/dl). In contrast to previous years, the HDL cholesterol levels in women in 2003 were markedly affected by education level and socioeconomic status, averaging 56 +/- 9 mg/dl in those with a university education and 48 +/- 12 mg/dl in those with a primary school education. Part of this difference could be explained by less smoking and more exercise and lower body mass index (average 25.6 +/- 4.9 vs 29.7 +/- 5.1 kg/m(2)) of the highly educated women. It is important to note the increase in the prevalence of obesity between the 1990 to 1993 interval and 2003 in men and women,,including a remarkable change from 9.4% to 45.2% among women with a primary school education. None of these factors affected the HDL cholesterol levels of men by > 2 mg/dl at any of the 3 points. In conclusion, because CRD risk changes by as much as 2% to 4% per 1 mg/dl difference in HDL cholesterol level, the 8 mg/dl difference may reflect as much as a 20% to 30% reduction in CHD risk associated with the benefit of higher education in women. Why education failed to affect the HDL cholesterol levels in Turkish men remains unclear. (c) 2005 Elsevier Inc. All rights reserved.

Resume L’utilisation massive d’antibiotiques a large spectre favorise l’emergence de bacteries multiresistantes. Objectifs. – Les objectifs de ce travail ont ete d’etudier les modes d’utilisation des antibiotiques et d’etablir la correlation entre les prescriptions d’antibiotiques et les recommandations dans une unite de soins intensifs neonatals. Materiel et methodes. – Il s’agit d’une etude prospective incluant pendant 6 mois tous les nouveau-nes admis en reanimation et recevant un traitement antibiotique. Les donnees recueillies comprenaient les indications, les criteres de decision d’antibiotherapie, la duree du traitement et le motif d’arret. La correlation prescription–recommandation etait jugee a posteriori par un medecin non prescripteur. Cent seize nouveau-nes ont ete inclus dont neuf avaient recu un traitement antibiotique a plusieurs reprises. L’âge gestationnel moyen etait de 33,5 semaines d’amenorrhee (SA). Dans 82 % des cas, le motif d’hospitalisation etait une detresse respiratoire. Resultats. – Les indications principales du traitement antibiotique etaient : l’infection primaire (78 %), l’infection nosocomiale (17 %), la prophylaxie postoperatoire (5 %). L’infection primaire etait dominee par la suspicion d’infection maternofœtale (SIMF) : 96 %. Dans 49 % des cas, la SIMF n’etait pas confirmee justifiant l’arret du traitement dans les 3 jours suivant son instauration. Soixante pour cent des infections nosocomiales concernaient des nouveau-nes de moins de 28 SA. Les criteres bacteriologiques ne jouaient un role decisionnel que dans les infections nosocomiales. La non observance des protocoles recommandes representait 9 % des enfants traites et concernait majoritairement une duree excessive de traitement. Conclusion. – Ces resultats montrent : 1) une majorite d’indication d’antibiotiques pour SIMF non confirmee ; 2) un faible taux d’infections nosocomiales ; 3) des infections nosocomiales principalement chez les grands prematures ; 4) moins de 10 % de non observances des protocoles. Cette etude montre la necessite d’etablir en reanimation neonatale des protocoles de traitements antibiotiques avec des criteres plus precis et de les evaluer regulierement.

International audience; In order to study the safety and the immunogenicity of the South African vaccine against the serotype 2 bluetongue virus, two groups of seven sheep were vaccinated with the vaccine used in the French island of Corsica. Vaccinated and nonvaccinated sheep were observed clinically and their rectal temperatures were recorded daily. The serological response in vaccinated animals confirmed the immunogenicity of the vaccine. Post-vaccinal viraemia was investigated and the vaccine genome was detected by reverse transcription polymerase chain reaction (RT-PCR). No viraemia was observed at post-vaccination days 4, 7 and 11 but the vaccine strain of virus was detected by RT-PCR throughout the experiment. The thermostability of the vaccine was also evaluated. The vaccine titre strongly decreased at temperatures higher than 35 degreesC.

In Turkish adults, HDL cholesterol (HDL-C) levels are 10–15 mg/dl lower than those of adults in western Europe and the United States. In this study, we determined whether HDL-C levels in Turks are low from birth to adulthood and assessed the effect of socioeconomic status (SES) on plasma lipids and lipoproteins. Analyses of cord blood from 105 Turkish newborns showed low levels of plasma cholesterol (~60 mg/dl) and HDL-C (~30 mg/dl), consistent with results from other Western ethnic groups. Prepubescent 8- to 10-year-old Turkish boys and girls of upper (n = 82) and lower (n = 143) SES had high HDL-C levels (50–60 mg/dl) similar to those of western European children. However, the cholesterol (154–158 mg/dl) and HDL-C (55–58 mg/dl) levels of upper SES children were ~25 and ~12 mg/dl higher, respectively, than those of lower SES children. Height, weight, skinfold thickness, and estimated body fat were greater in the upper SES children and appeared to reflect dietary differences. Upper SES children consumed more total fat (~35% vs. 25% of total calories), including more saturated fat of animal origin, and less carbohydrate (~50% vs. 62% of total calories), consistent with their elevated plasma cholesterol levels. Carbohydrate intake correlated inversely with the HDL-C level. The HDL-C levels in the prepubescent children, especially those of higher SES, who consumed diets more like western Europeans, decreased markedly to adult levels, with males exhibiting a ~20 mg/dl decrease (from 58 to 37 mg/dl) and females a ~13 mg/dl decrease (from 55 to 42 mg/dl). SES did not affect HDL-C levels in adults. The profound decrease may reflect alterations in androgen/estrogen balance in Turks at puberty and a modulation of hepatic lipase affecting HDL-C levels. —Mahley, R. W., P. Arslan, G. Pekcan, G. M. Pepin, A. Agacdiken, N. Karaagaoglu, N. Rakicioglu, B. Nursal, P. Dayanikli, K. E. Palaoglu, and T. P. Bersot. Plasma lipids in Turkish children: impact of puberty, socioeconomic status, and nutrition on plasma cholesterol and HDL. J. Lipid Res. 2001. 42: 1996–2006.

We investigated the effects of size-dependent encounter and susceptibility, the role of variation in the size distribution of predators, and the timing of prey-predator interaction during the larval phase in shaping the length frequency distribution of surviving fish larvae. These analyses based on general empirical size-dependent relationships may have broad implications in understanding larval fish cohort dynamics. We demonstrated that the formulations of encounter and susceptibility to predation counteract each other, an increased range of predator sizes reduces only slightly the evidence for size-selective mortality, and synchronous spawning and hatching events have the potential to yield strong size-selective mortality of a cohort of fish larvae. The important factors in generating size-selective mortality are either the timing of encounters between fish larvae and their predators or high mortality rates. We demonstrated a direct relationship between the potential of size-selective mortality and the overall mortality rate of the cohort. We suggest that it may be difficult to detect the effect of size-dependent processes in the field. A better understanding of the factors influencing encounter represents a critical element in extrapolating laboratory studies of predation to the field. Resume : Nous avons evalue les effets de rencontre et susceptibilite (tous deux specifiques aux tailles des proies et des predateurs), le role de la variation de taille des predateurs et l'effet du degre de synchronisme de l'interaction proie-predateur pendant le stage larvaire sur la distribution de tailles des larves de poissons. Ces analyses basees sur des relations empiriques generales pourraient avoir des consequences globales pour comprendre les dynamiques des cohortes de larves de poisson. Nous avons demontre que les fonctions de rencontre et de susceptibilite a la predation se neutralisent, qu'une augmentation de la gamme de tailles des predateurs ne reduit que tres peu la mortalite selective des larves et qu'une synchronisation du frai et de l'eclosion a le potentiel de generer une importante mortalite selective des tailles. Les facteurs importants pour generer une mortalite selective sont une synchronisation des rencontres entre les larves de poissons et leurs predateurs et un haut taux de mortalite. Nous demontrons une relation directe entre le potentiel selectif de mortalite et la mortalite totale de la cohorte des poissons larvaires. Nous suggerons qu'il peut etre difficile de detecter les effets de processus selectifs sur le terrain. Une comprehension plus exhaustive des facteurs influencants les taux de rencontres est un element cle pour l'extrapolation des etudes de predation en laboratoires sur le terrain.

The efferent lymph duct of the ovine prescapular lymph node was cannulated, and Salmonella abortusovis (SAO), a specific pathogen for sheep inducing abortion and mortality of newborn lambs, was inoculated by the subcutaneous route in this lymph node drained area. While the prescapular lymph node draining the inoculation site represented an efficient barrier for the vaccinal SAO Rv6 strain spreading, SAO 15 5 virulent bacteria were steadily detected in efferent lymph of infected sheep. The inoculation of the virulent strain of SAO induced a greater increase of the cell output than did the attenuated vaccinal strain, but proportions of blast cells appearing in the efferent lymph were similar in both cases. Flow cytometry analysis showed that B and T cell outputs were both increased during SAO infections, but while T cell subset proportions slightly decreased, B cell percentages significantly rose, and, at the peak response, almost all of the lymphoblast cells were activated B cells. Typical antibody profiles characteristic of a primary immune response were observed, and antibody titres were greater in the efferent lymph of animals inoculated with the virulent strain of SAO. Many of the cytokine mRNAs we investigated were steadily detected by RT-PCR in efferent lymph cells of control sheep, but frequencies of detection of IL-2, IFNγ, IL-1β and TNFα mRNAs were augmented in efferent lymph cells following inoculation of both SAO virulent or vaccinal strains. IL-10 and IL-8 mRNAs could only be detected after a SAO inoculation, while detection of IL-4 mRNAs was increased only in efferent lymph cells from SAO virulent strain-infected sheep. The efferent lymph cannulation technique thus appeared a very powerful way to study the in vivo development of the immune response to SAO, in its natural host, the sheep.

A monoclonal antibody (mAb) specific for ovine IL-1 beta was produced and, in conjunction with a polyclonal rabbit antiserum, used to develop a sensitive enzyme immunoassay (EIA) for ovine interleukin 1 beta (IL-1 beta). The mAb neutralised the activity of recombinant ovine IL-1 beta (rOvIL-1 beta) and native OvIL-1 in an ovine thymocyte proliferation assay. However, it did not neutralise the biological activity of rOvIL-1 beta in the murine NOB1/CTLL assay. The mAb did not react with rOvIL-1 alpha, IL-2, IL-4, IL-8, tumor necrosis factor-alpha, gamma-interferon or recombinant human IL-1 beta in indirect EIA. Immunohistological staining of activated alveolar macrophages and frozen lymph node sections sections demonstrated that the mAb detected IL-1 beta secreted by ovine macrophages (CD11c-positive). The EIA was highly sensitive, detecting less than 50 pg ml-1 of rOvIL-1 beta and low levels of native IL-1 beta in supernatants from lipopolysaccharide-stimulated macrophages. The EIA did not detect heat-inactivated IL-1 beta.

We screened 192 patients infected with human immunodeficiency virus (HIV) to examine the relation between CD4+ lymphocyte counts and cytomegalovirus (CMV) viremia and the occurrence of CMV disease and subsequent duration of survival. When we stratified the viremic patients by CD4+ lymphocyte counts, the proportions were as follows: 150/mm3, 1 (1.5%) of 62. After a mean follow-up period of 8.5 months, 21 (11%) of 192 patients developed CMV disease. The probability of developing CMV disease at 6 months was 13% when the CD4+ lymphocyte count was 100/mm3; this probability was 46% for viremic patients and 1% for nonviremic patients. In a multivariate analysis, CMV viremia was independently prognostic of CMV disease (relative risk, 22.03; 95% confidence interval, 6.49-78.97; P < .001), whereas a CD4+ lymphocyte count of

Reproductive biotechnologies are essential to improve the gene pool in small ruminants. Although embryo transfer (ET) and artificial insemination (AI) greatly reduce the risk of pathogen transmission, few studies have been performed to quantify this risk. The aim of this review is to contribute to the elements needed to evaluate the risk of lentivirus transmission in small ruminants (SRLV) during ET, from embryos produced in vitro or in vivo, and with the use of the semen destined for AI. The purpose is to consider the genetic possibilities of producing uninfected embryos from infected females and males or bearers of the SRLV genome. We have reviewed various studies that evaluate the risk of SRLV transmission through genital tissues, fluids, cells, and flushing media from female and male animals. We have only included studies that apply the recommendations of the International Embryo Transfer Society, to obtain SRLV-free offspring from infected female animals using ET, and the justification for using healthy male animals, free from lentivirus, as semen donors for AI. As such, ET and AI will be used as routine reproductive techniques, with the application of the recommendations of the International Embryo Transfer Society and World Organization for Animal Health.

Lymphoscintigraphy usually involves labeled microparticles or colloids that distribute in the lymph flow. A new strategy for imaging pathological lymph nodes would be the targeting of macrophages recruited in these lesions. The potential for lymphoscintigraphy of the highly diffusible J001X acylated polygalactoside labeled with 99mTc was studied and compared to usual colloidal agents in a model of infectious granulomas developed in sheep. Scintigraphic and histological assessment of the specificity of targeting was performed using a MAb (OM1) raised against ovine macrophages taken as reference. This study has evidenced the ability of J001X specifically to image pathologic lymph nodes and more especially the second lymph node in the same chain with a significant scintigraphic contrast.

Ovine tumour necrosis factor-alpha (OvTNF-alpha) was cloned by reverse transcription-polymerase reaction using RNA isolated from lipopolysaccharide (LPS)-stimulated alveolar macrophages and primers based on the human TNF-alpha cDNA sequence. An expression vector carrying the coding sequence of the mature form of ovine TNF was constructed. The recombinant Ov-TNF alpha (rOvTNF-alpha) was expressed as a glutathione-S-transferase (GST) fusion protein. It was cleaved with thrombin to yield rOvTNF free of the GST moiety. Growth at a lower temperature of 30 degrees C and use of Escherichia coli strains AM207, AM305, E392 and NM522 did not improve the recovery of rOvTNF-alpha from the soluble fraction to a significant extent. Purification of recombinant proteins was achieved rapidly and easily by affinity chromatography using glutathione-Sepharose. Yields of pure rOvTNF-alpha achieved in E. coli JM109 and AM207 were approximately 1 mg L-1. Both rOvTNF-alpha and recombinant human TNF-alpha (rhTNF-alpha) exerted cytotoxicity on L929 cells. However, rOvTNF-alpha but not rhTNF-alpha stimulated proliferation of ovine thymocytes. Maximum levels of TNF-alpha mRNA expression by LPS-stimulated ovine alveolar macrophages were detected at approximately 4 h post-stimulation.

The monoclonal antibodies (82 mAbs) included in the Second Workshop that belonged to agreed named bovine CD and workshop clusters were tested for their reactivity and tissue distribution on (1) normal sheep lymph nodes and (2) pathological sheep lymph nodes. Pathological lymph nodes were induced following experimental infection with Corynebacterium pseudotuberculosis and were characterized by the presence of typical pyogranulomas. Amongst the 82 mAbs tested, 38 reacted with sheep lymph nodes. The results of these tests are presented and discussed.

The objective of this study was to determine whether MVV can be transmitted by ovine embryos produced in vitro and whether the zona pellucida (ZP) provides any protection against MVV infection. Zona pellucida (ZP)-intact and ZP-free embryos, produced in vitro, at the 8-16 cell stage, were cocultured for 72h in an insert over an ovine oviduct epithelial cell (OOEC)-goat synovial membrane (GSM) cell monolayer that had been previously infected with MVV (K1514 strain). The embryos were then washed and transferred to either direct contact or an insert over a fresh GSM cell monolayer for 6 h. The presence of MVV was detected using RT-PCR on the ten washing fluids and by the observation of typical cytopathic effects (CPE) in the GSM cell monolayer, which was cultured for 6 weeks. This experiment was repeated 4 times with the same results: MVV viral RNA was detected using RT-PCR in the first three washing media, while subsequent baths were always negative. Specific cytopathic effects of MVV infection and MVV-proviral DNA were detected in GSM cells that were used as a viral indicator and cocultured in direct contact or as an insert with MVV-exposed ZP-free embryos. However, no signs of MVV infection were detected in cells that were cocultured with exposed ZP-intact or non-exposed embryos. This study clearly demonstrates that (i) in vitro, ZP-free, early ovine embryos, which had been exposed to 10(3) TCID(50)/m MVV in vitro, are capable of transmitting the virus to susceptible GSM target cells, and that (ii) the JETS recommendations for handling in vivo produced bovine embryos (use of ZP-intact embryos without adherent material and performing ten washes) are effective for the elimination of in vitro MVV infection from in vitro produced ovine embryos. The absence of interaction between ZP-intact embryos and MVV suggests that the in vitro produced embryo zona pellucida provides an effective protective barrier. (C) 2010 Elsevier Inc. All rights reserved.

Rift Valley Fever (RVF) is a zoonotic arbovirosis. Among animals, it mainly affects ruminants, causing abortions in gravid females and mortality among young animals. In humans, RVF virus infection is usually asymptomatic or characterized by a moderate fever. However, in 1 to 3% of cases, more severe forms of the disease (hepatitis, encephalitis, retinitis, hemorrhagic fever) can lead to the death of infected individuals or to major sequels. The RVF virus (Bunyaviridae, genus Phlebovirus) was identified for the first time in the 1930s in Kenya. It then spread over almost all African countries, sometimes causing major epizootics/epidemics. In 2000, the virus was carried out of Africa, in the Middle East Arabian Peninsula. In 2007-2008, Eastern-African countries, including Madagascar, reported significant episodes of RVF virus, this was also the case for the Comoros archipelago and the French island of Mayotte. This ability to spread associated with many vectors, including in Europe, and high viral loads in infected animals led the health authorities worldwide to warn about the potential emergence of RVF virus in areas with a temperate climate. The awareness has increased in recent years with climate changes, which may possibly modify the vector distribution and competence, and prompted many RVF virus-free countries to better prepare for a potential implantation of RVF.

Infection and pyogranulomas induced by Corynebacterium pseudotuberculosis were experimentally reproduced in lambs. In two separate experiments, bacterial multiplication and dissemination were studied in 30 male lambs inoculated subcutaneously into the right ear with 1.1 or 1.5 × 10 8 viable C. pseudotuberculosis strain 19R. Infected lambs were necropsied at various times until the 28th day following inoculation. After a transient hyperthermia and a strong local inflammatory reaction, an abscess developed in the right ear from postinoculation day (PID) 6; it enlarged until PID 14 and stabilized thereafter and was associated with adenopathy of lymph nodes draining the head. Three acute phase indicators of inflammation were followed in 14 out of 30 lambs; plasma levels of copper and haptoglobin increased rapidly following inoculation whereas zinc levels decreased. The peaks were reached from PID 1 to 5, and thereafter the values came back slowly to the baseline. Antibodies against C. pseudotuberculosis exotoxin increased from PID 5 and reached a plateau on PID 21. Bacterial dissemination, assessed by the number of infected organs per lamb, was maximal on PID 16 and then stabilized until the end of the experiment. Lungs were infected in seven out of 18 lambs necropsied on PID 28. These results demonstrate a significant relationship between the clinical score of superficial lumph nodes or inoculation site and the infection level of these organs, and an early localization of pyogranulomatous lesions in regional lymph nodes. The subsequent development of the disease was related to the enlargement of these lesions and, in some animals, to a bacterial dissemination from primary sites of infection in the right prescapular lymph node and in the lung.

Staphylococcus aureus is recognized worldwide as a major pathogen causing clinical or subclinical intramammary infections in lactating sheep, goats and cows. The present study was carried out to compare 65 S. aureus isolates mainly obtained from nasal carriage and subclinical mastitis in dairy sheep and 43 isolates obtained from subclinical mastitis from 22 goats and 21 cows. A DNA microarray, containing probes against 190 true or putative virulence factors, was used to detect the presence of the virulence genes. Their presence/absence was independently assessed by PCR for the genes of interest. Sheep isolates obtained from the nostrils or the udders did not show any significant tissue specific virulence factor. The dominant pulse-field electrophoresis profile (OV/OV'), associated with spa clonal complex spa-CC 1773, matched mainly with the agr group III and was only found in ovine and caprine isolates. This clone was more specifically characterized by the prevalence of the following virulence genes: lpl4, ssl6, bsaA1, bsaB, bsaP, SAV0812. Moreover, seven virulence-associated genes (lpl1, sel, sec, tst, lukF-PV-like component, lukM, SAV0876) were associated with isolates from small ruminants, while the egc cluster, fhuD1, abiF and SAV2496 with bovine isolates. This genomic study suggests the existence of lineage- and host-specific genes leading to the development of host-specific pathogenic traits of S. aureus isolates.

International audience; The aim of this study was to demonstrate that embryo transfer can be used to produce CAEV-free kids from CAEV-infected biological mothers when appropriate procedure is implemented. Twenty-eight goats that had tested positive for CAEV using PCR on vaginal secretions were used as embryo donors. Embryos with intact-ZP were selected and washed 10 times; they were then frozen and used for transfer into CAEV-free recipient goats. Nineteen of the 49 recipient goats gave birth, producing a total of 23 kids. Three blood samples were taken from each recipient goat, 10 days before, during, and 10 days after parturition; these were tested for CAEV antibodies using ELISA and for CAEV proviral DNA using PCR. The mothers were then euthanized. Tissue samples were taken from the lungs, udder, and retromammary and prescapular lymph nodes. The kids were separated from their mothers at birth. Seven of them died. At 4 months of age, 16 kids were subjected to drug-induced immunosuppression. Blood samples were taken every month from birth to 4 months of age; samples were then taken on days 15, 21, and 28 after the start of the immunosuppressive treatment. The kids were then euthanized and tissue samples taken from the carpal synovial membrane, lung tissue, prescapular lymph nodes, inguinal and retromammary lymph nodes, and uterus. All samples from the 19 recipient goats and 23 kids were found to be negative for CAEV antibodies and/or CAEV proviral DNA. Under acute conditions for infection this study clearly demonstrates that embryo transfer can be safely used to produce CAEV-free neonates from infected CAEV donors.

The recruitment of polymorphonuclear leucocytes (PMNs) during the development of experimental pyogranulomas induced by Corynebacterium pseudotuberculosis was followed in nine male lambs by scintigraphic examination. Autologous blood PMNs were labelled with 99m-technetium or 111-indium and were re-injected intravenously into infected lambs. The functional properties of the labelled cells were monitored 1) in vitro by measuring their phagocytic and bactericidal activity against C. pseudotuberculosis and their chemotaxis under agarose, and 2) in vivo by following scintigraphically their capacity to accumulate in an inflammatory focus induced by intradermal injection of latex beads coated with Salmonella abortus equi lipopolysaccharide. Following inoculation of corynebacteria into the right ear of lambs, radioactive foci were observed to be localized in the right ear and in the draining lymph nodes during the 4 days following inoculation. Histopathological examination performed 32 h after inoculation confirmed the intense accumulation of PMNs at these sites. With the exception of one animal, which presented visible foci in the neck 14 days postinoculation, no radioactive foci were observed during the later phases of experimental infection, despite the presence of multiple pyogranulomas which were confirmed by bacteriological examination after necropsy of the lambs. Histopathological examination of these lesions revealed layers of fibroblasts, lymphocytes, and macrophages surrounding a necrotic centre. The results of these studies suggest that the contribution of PMNs during the chronic phase of inflammation is considerably reduced in comparison with the acute inflammatory phase of the infectious process.

International audience; Salmonella enterica subsp. enterica ser. Abortusovis, a sheep-adapted serotype, causes a contagious disease. Abortion is the major symptom and the main source of contamination. Research on this ovine disease may aid farmers, but may also contribute to comparative biological knowledge. Innate resistance partly controlled by the Ity locus, increased resistance to reinfection and humoral and T-cell-mediated immunity were observations gained with a murine model. In ewes, abortion regularly occurs following subcutaneous challenge carried out from the third month of gestation onwards. This ovine model was used to evaluate prevention methods for Salmonella Abortusovis infection. One subcutaneous injection of a live attenuated lyophilized vaccine containing a selected streptomycin-independent reverse mutant was shown to protect ewes against abortion and excretion of Salmonella Abortusovis. This vaccine could be administered simultaneously with other commercial live vaccines such as Brucella melitensis Rev. 1 vaccine. In sheep, application of the vaccine to the conjunctiva (an easy, individual and hygienic route of mucosal vaccination) was followed by lymph node bacterial colonization and a serological response without local or general clinical reactions. The early events of natural infection remain to be explored, as do the mechanisms underlying the host specificity of Salmonella Abortusovis.

International audience; The aim of this study was to examine the Maedi-Visna virus (MVV) infection status of oocytes, cumulus cells, and follicular fluid taken from 140 ewes from breeding flocks. MVV proviral-DNA and MVV RNA were detected using nested-PCR and RT-PCR MVV gene amplification, respectively in the gag gene. Nested-PCR analysis for MVV proviral-DNA was positive in peripheral blood mononuclear cells in 37.1% (52/140) of ewes and in 44.6% (125/280) of ovarian cortex samples. The examination of samples taken from ovarian follicles demonstrated that 8/280 batches of cumulus cells contained MVV proviral-DNA, whereas none of the 280 batches of oocytes taken from the same ovaries and whose cumulus cells has been removed, was found to be PCR positive. This was confirmed by RT-PCR analysis showing no MVV-viral RNA detection in all batches of oocytes without cumulus cells (0/280) and follicular fluid samples taken from the last 88 ovaries (0/88). The purity of the oocyte fraction and the efficacy of cumulus cell removal from oocytes was proved by absence of granulosa cell-specific mRNA in all batches of oocytes lacking the cumulus cells, using RT-PCR. This is the first demonstration that ewe cumulus cells harbor MVV genome and despite being in contact with these infected-cumulus cells, the oocytes and follicular fluid remain free from infection. In addition, the enzymatic and mechanical procedures we used to remove infected-cumulus cells surrounding the oocytes, are effective to generate MVV free-oocytes from MVV-infected ewes.

Current guidelines for managing dyslipidemia qualify patients for treatment based on low-density lipoprotein cholesterol (LDL-C) levels and other risk factors for coronary heart disease (CHD). However, when LDL-C is the sole lipid criterion for initiating therapy, patients with levels below the treatment initiation threshold who are at high risk because of low levels (40 mg/dL) of high-density lipoprotein cholesterol (HDL-C) might not be identified. Twenty percent of male patients with CHD in the United States fall into this category. The total cholesterol/HDL-C (TC/HDL-C) ratio predicts CHD risk regardless of the absolute LDL-C and HDL-C.We compared guidelines based on TC/HDL-C and LDL-C with those recommended by the National Cholesterol Education Program Adult Treatment Panel III (ATP III). Both sets of guidelines were applied to 9837 adults (20 years of age) in the Turkish Heart Study, which has shown that 75% of men and 50% of women in Turkey have HDL-C40 mg/dL.ATP III guidelines identified 14% of Turkish adults, 20 years or older, as candidates for lifestyle treatment only and an additional 18% for drug treatment. In conjunction with ATP III LDL-C thresholds, the TC/HDL-C ratio (3.5, patients with CHD;or =6.0, 2+ risk factors,or =7.0, 0 to 1 risk factor) assigned lifestyle therapy alone to 18% and drug treatment to an additional 36%. Among primary prevention subjects at high risk because of age (menor =45 years; womenor =55 years), both sets of guidelines prescribed lifestyle therapy for only 5%; however, drug treatment was recommended for an additional 13% by ATP III guidelines and an additional 18% by TC/HDL-C and LDL-C.In populations at risk for CHD caused by low HDL-C, qualification of subjects for treatment based on either the TC/HDL-C ratio or LDL-C thresholds identifies more high-risk subjects for treatment than LDL-C threshold values alone, and use of the ratio, instead of risk tables, simplifies the approach for physicians.

The increasing use of wide spectrum antibiotics has been reported to be associated with a greater prevalence of multi-resistant bacteria.The aims of this study were to survey the use of antibiotics and to evaluate the correlations between patterns of prescription of antibiotics and prescription guidelines in a neonatal intensive care unit.In this 6-month study, all newborns admitted to the NICU and treated with antibiotics were included. Data regarding criteria of antibiotic prescription, length of treatment, and criteria of withdrawing treatment were collected. The correlation between prescriptions and guidelines was evaluated a posteriori by a non-prescriber physician. One hundred and sixteen newborns were included, of whom nine had received antibiotics on more than one occasion. Mean gestational age was 33.5 weeks. In 82% of cases, the reason for hospitalisation was respiratory distress syndrome.Patients received systemic antibiotics for primary infection (78%), nosocomial infection (17%) and postsurgical prophylaxis (5%). Suspected foeto-maternal infections (SFMI) were the dominant features of primary infection (96%). In 49% of cases, suspected infection was not proven and justified withdrawal of treatment within 3 days. Sixty percent of nosocomial infections occurred in newborns with gestational ages of less than 28 weeks. Bacterial criteria were decision-making factors only in nosocomial infections. An absence of observance of guidelines occurred in 9% of treated newborns, and in most cases involved excessive length of treatment.These results show: (1) the majority of antibiotic prescriptions were for not proven SMFI; (2) a low rate of nosocomial infections; (3) the predominance of nosocomial infections in premature newborns; (4) less than 10% of non-observance of guidelines. It appears necessary to develop more precise guidelines to limit antibiotic use and to evaluate them regularly.

Measuring the psychological well-being of people with physical impairments could provide relevant information to occupational therapists. The aim of this study was to verify psychometric properties of a psychological well-being test called Test de personnalité PER (PER). This test was administered to two samples of people with physical impairments. Two time measurements were collected within a group of 36 individuals and one single measure within another group of 79 individuals. Comparisons between time measurements, between groups and with the normative group of the PER were performed in an attempt to verify the sensitivity, the capacity to discriminate between known groups, and the construct validity of the PER. One section of the Sickness Impact Profile measuring psychological well-being was administered to the same groups to verify the concurrent criterion validity of the PER. The results indicate that the PER has sufficient psychometric qualities.

The repeated use of copper (Cu) fungicides to control vine downy mildew has led to long-term accumulation of Cu in vineyard soils which now raises the issue of the potential bioavailability of Cu for various living organisms including plant species. The bioavailable Cu can be defined as the portion of soil Cu that can be taken up by roots, for a given plant species. In order to evaluate the bioavailability of Cu to plants, a pot experiment was conducted in glasshouse conditions with a crop species (maize) and 12 soils sampled in the upper horizon of 10 vineyard plots (total Cu ranging from 38 to 251 mg kg-1) and two woodland plots (control soils that had not received any Cu application; total Cu amounting to 20-26 mg kg-1). These soils were selected for their diverse physical (large range of particle size distribution) and chemical (from acid to calcareous soils) properties. After 35 days of growth, plant shoots were harvested for analysis. The roots were separated from soil particles for further analysis. The concentrations of Cu in the roots and aerial parts of the maize were then compared with the amounts of Cu extracted from the soil by a range of conventional extractants. Observed Cu concentrations in maize roots which have grown in contaminated vineyard soils were very high (between 90 and 600 mg kg-1), whereas Cu concentrations in the aerial parts varied only slightly and remained low (< 18 mg kg-1). Root Cu concentrations observed for maize increased with increasing total Cu content in the soil and with decreasing soil CEC. Cu accumulation in maize roots may be as high in calcareous soils as in acid soils, suggesting that soil pH had little influence. In the case of the vineyard soils studied, the lack of correlation found for maize between Cu concentrations in roots and in the aerial parts, suggests that an analysis of the aerial parts would not be a good indicator of plant Cu uptake, as it provides no insight into the real amount of Cu transferred from the soil to the plant. For maize, our results show that extraction with organic complexing agents (EDTA, DTPA) and extraction with ammonium acetate seem to provide a reasonably good estimate of root Cu concentration.

The degradation of leucine generates aroma compounds involved in the typical flavour of dry fermented sausage. The ability of lactic acid bacteria and staphylococci of meat origin to produce aromatic compounds from leucine was studied. Whole cells were incubated with3H-labelled leucine under different conditions. The radioactive metabolites produced were analysed by high performance liquid chromatography. All the strains studied were able to catabolise leucine but catabolic profiles were quantitatively and qualitatively different. The catabolism of leucine by Lactobacillus sakei,Lactobacillus curvatus and Pediococcus acidilactici was very low and required α -ketoglutarate, which indicates that an aminotransferase was involved in the first step of leucine catabolism. Carnobacterium piscicola produced a large amount of 3-methyl butanal, whereas Staphylococcus carnosus mainly produced 3-methyl butanoic acid. Leucine was mainly degraded into α -ketoisocaproic acid by Lactobacillus plantarum and Carnobacterium divergens. Nitrate affected leucine catabolism only in S. carnosus.

Salmonella abortusovis strain Rv6 ( Sao Rv6) is a live attenuated vaccine used for a few years to protect ewes against abortive salmonellosis. As Salmonellae, particularly Salmonella aro mutants, have considerable potential as vehicles for the presentation of heterologous vaccine antigens, Sao Rv6 was tested in order to develop a vaccinal vehicle for small ruminants. Five vector plasmids were tested in Sao Rv6; these plasmids, which carry Maltose Binding Protein (MBP) expressed as protein, but differ in their promotors, had been previously tested in S. typhimurium strain SL3261, and were transferred into Sao Rv6. The five plasmids were stable in vitro, and the recombinant Sao Rv6 expressed MBP at various levels. Intraperitoneal infection of OF1 mice with the recombinant bacteria did not modify the characteristics of Sao Rv6: dissemination and infection levels were similar in all groups and all mice developed antibodies to Salmonella antigens as measured by ELISA. In contrast, only animals immunized with Sao Rv6 carrying the pNTE plasmid developed a serum antibody response to MBP. This plasmid was then tested in sheep; following subcutaneous immunization with Sao Rv6-pNTE, dissemination and infection levels were not modified in comparison with sheep immunized with Sao Rv6 lacking plasmid. Antibodies specific to MBP were detected in sera of sheep immunized with Sao Rv6-pNTE, purified MBP, and with S. typhimurium SL3261-pNTE as positive controls. These results demonstrate that Sao Rv6 can be used as a vehicle for heterologous antigens in sheep with pNTE as plasmid vector.

Foodborne diseases, in particular those related to meat and meat products, have recently become a matter of great public concern. Sheep and goat meat can transmit infections and diseases either through handling during preparation procedures or as a result of ingestion by the consumer. The authors highlight the second route of contamination in relation to meat and meat products from small ruminants in European countries. Among the most important diseases transmitted by mutton and goat meat, toxoplasmosis remains the greatest threat, particularly in immuno-compromised people and in pregnant women. Other pathogens which may be associated with the consumption of meat from small ruminants include: Clostridium perfringens, Cryptosporidium parvum and Campylobacter jejuni. As with other ruminant species, Escherichia coli O157:H7 can be considered as an emerging pathogen, for which control efforts must be made. The classical zoonoses (brucellosis, Q fever, hydatidosis) are also presented here, although the major source of contamination for these diseases remains contact with infected animals or the handling of carcasses. The fact that the association of foodborne diseases with mutton and goat meat is less frequent than with the meat of other animal species should be noted, for the following reasons: a) lower levels of production; b) less intensive production, leading to a weaker microbial contamination; c) mutton and goat meat are subjected to processing less often than other meats; d) the usual boiling or cooking processes.

Corynebacterium pseudotuberculosis is the causative agent of caseous lymphadenitis in sheep and goats. This disease is characterized by the development of pyogranulomas in the lymph nodes and lung tissue. To measure the cytokine gene expression in C pseudotuberculosis lesions, sheep were inoculated with two attenuated strains (Tox- and PLD-t) and a wild-type (WT) strain of C pseudotuberculosis and were necropsied at 7 or 28 days post-inoculation. The Tox- strain showed a strong reduction in virulence as assessed by the absence of disseminating lesions in the lymph nodes draining the inoculation site in contrast with the WT strain. The PLD-t strain showed an intermediate reduction in virulence. The two attenuated strains, however, induced the same amount of antibodies and IFN-gamma production as the WT strain. Using a semi-quantitative RT-PCR technique, the expression of inflammatory cytokines was found to be higher in the inoculation site, whereas expression of T-cell associated cytokines was more intense in the draining lymph node. On the whole, the infected sheep produced high levels of cytokines in at least one organ on days 7 or 28 post-inoculation. No significant differences in cytokine gene expression were shown between sheep infected with strains differing in virulence. Higher cytokine expression was measured in sheep with pyogranulomas in the draining lymph nodes as compared to those without, especially for interleukin-1 beta and interleukin-8. Overall, these results taken together confirmed the attenuation of virulence in Tox- and PLD-t strains of C pseudotuberculosis and showed the important role of PLD in disseminating the bacteria from the inoculation site to the draining lymph nodes. The pathogenesis of ovine caseious lymphadenitis was shown to be associated with production of cytokines at the pyogranuloma level, but the local cytokine patterns associated with different courses of infection were not distinguished.

OBJECTIVES: To describe treatment of insomnia in general practice and to identify family physicians' training needs in this area. DESIGN: Mail survey using Dillman's total design method. PARTICIPANTS: A sampling of 484 general practitioners in the Quebec City area was done to provide roughly equal representation of six practice settings. The response rate was 65%; 295 of the 315 questionnaires returned were selected for analysis. RESULTS: Most physicians reported treating insomnia with general advice and lifestyle changes; 25% reported prescribing hypnotics frequently; 56% reported they prescribed them occasionally. Although 58% often recommend relaxation techniques, only 8% taught these techniques to their patients. Other cognitive and behavioral approaches are rarely used. Most felt that training in treating insomnia should be offered. CONCLUSION: Cognitive and behavioral approaches are very effective approaches are very effective nonpharmacological treatments for insomnia. General practitioners make little use of these treatments that could be easily integrated into clinical practice. Strategies for increasing their use discussed.

The cellular composition of 46 pyogranulomas experimentally induced with Corynebacterium pseudotuberculosis in sheep was determined by immunohistochemistry. Lesions localized in inoculation sites or draining lymph nodes consisted of macrophage and lymphocyte layers distributed around a necrotic center and surrounded by a fibrous capsule. In immature lesions, T cells of the CD4+ subset predominated, whereas in mature lesions proportions of CD8+ T lymphocytes and cells expressing the γ/δ chains for the T cell receptor increased. Numerous pyogranuloma cells expressed the interleukin-2 receptor. In addition to these general characteristics, a large individual variability in the proportions of macrophage and T cell subsets was observed for lesions of the same age, in particular for epithelioid macrophages. This heterogeneity suggests a different cellular pattern in relation to the persistence or the elimination of bacteria by the host. J. Leukoc. Biol. 56: 666–670; 1994.

Histological responses to the early phase of infection were compared in parotid lymph nodes of lambs infected by the subcutaneous route into the right eyelid with either a virulent or an attenuated strain of Salmonella abortusovis. The right parotid lymph nodes showed a massive PMN infiltration for the first days of infection for both strains. From day 6, the infected lymph nodes developed a lymphoid hyperplasia with prominent germinal centers independent of strain type. The virulent strain of S. abortusovis induced focal lesions in 2 out of 6 lambs necropsied on days 6 and 10, and provoked a systemic infection evidenced by the regular colonization of spleen on day 6. In contrast, no focal lesion and a restricted bacterial dissemination were observed in lambs infected with the vaccinal strain.

To determine circulating viral load in HIV-2-infected individuals.Viral load was determined in 40 HIV-2-infected adults using standardized quantitative cell and qualitative plasma viraemia assays. We also tested for proviral HIV-2 DNA using single and nested polymerase chain reaction (PCR) in fresh lymphocytes from 27 subjects. The results were compared, on the basis of the CD4+ lymphocyte count, with our published data for HIV-1 infection.HIV-2 was isolated from peripheral blood mononuclear cells (PBMC) from 19 individuals and plasma from four patients. The rate of cell and plasma viraemia positivity correlated with the CD4+ cell count and HIV-2 virus load increased as the CD4+ cell count fell. The cellular HIV-2 load in the patients with a CD4+ count200 x 10(6)/l was similar to reported values for HIV-1, but the HIV-2 isolation rate from the plasma of these individuals was significantly lower than for HIV-1. When the CD4+ count was between 200 and 500 x 10(6)/l, the rate of HIV-2 isolation from plasma and the cellular virus load were both significantly lower than for HIV-1. When the CD4+ count was500 x 10(6)/l, HIV-1 and HIV-2 were undetectable in plasma and HIV-1 was isolated from PBMC in significantly more cases than HIV-2. By single PCR, amplification were positive in 14 out of 27 subjects and there was a correlation between positivity and CD4+ cell count. By nested PCR, only four of the 27 subjects, all with a high CD4+ count, remained negative.Differences in viral load between individuals infected with HIV-2 and those infected with HIV-1 could partly account for reported differences in the pathogenicity of the two viruses.

HIV resistance to nucleoside analogues such as zidovudine (AZT) is to date a source of concern, even if its clinical significance is yet to be determined. Phenotypic and genotypic data concerning HIV resistance will be presented, then the potential benefits of nucleoside combinations will be discussed.

Low starch mutants of Chlamydomonas reinhardtii were isolated after x-ray mutagenesis of wild-type strain 137C. The mutants accumulated 20-40% of the normal amount and displayed a 2-fold decrease of the total glycogen-primed soluble starch synthase activity. Three different mutant alleles of the st-3 gene were isolated that were characterized by similar defects and displayed a net increase in amylose content. Amylose-primed synthesis of glucan in native gels revealed a complete wipe out of one of the soluble starch synthases. Zymograms and kinetic analyses performed both in the mutant and in partially purified wild type extracts reveal at least two distinct activities that are partly analogous to higher plant soluble starch synthases I and II (SSI and II). The st-3 mutants were defective for SSII. Methylation and debranching of the purified amylopectin fraction clearly show a decrease in the number of intermediate size glucans (dp8 to 50) and an absolute and relative increase of very short glucans (dp2 to 7). These results suggest that a soluble starch synthase may be necessary for the synthesis or maintenance of intermediate size glucans that are the main component of the branched clusters of amylopectin.

In order to characterize in situ the macrophages present in experimental pyogranulomas induced in lambs with Corynebacterium pseudotuberculosis, a set of monoclonal antibodies (MAbs) was produced following immunization of BALB/c mice with alveolar macrophages from healthy sheep. Three MAbs were retained after two steps of screening using alveolar macrophages, peripheral blood lymphocytes, and polymorphonuclear leukocytes as target cells. Their reactivity was tested not only on macrophages in pyogranulomas but also on sections of various organs in steady-state conditions. One MAb, termed OM1, recognized the monocytes and the majority of cells of the mononuclear phagocyte system in lymphoid and nonlymphoid organs. The two other MAbs, OM2 and OM3, reacted with a subpopulation of alveolar macrophages and with other cell types in tissues, in particular with endothelial cells for the MAb OM2. On sections of experimental pyogranulomas that developed in lymph nodes draining the C. pseudotuberculosis-injected sites, MAb OM1 reacted with all the macrophages distributed in a palisade surrounding the necrotic center of the lesion from day 6 to day 28 postinoculation. The two other MAbs, OM2 and OM3, enabled two types of granulomas to be distinguished: one type was characterized by a large number of epithelioid cells stained by OM2; and the other was characterized by a few OM2-positive macrophages, whereas the OM3-positive cells were more numerous. These results show that macrophages are predominant cells in pyogranulomas and suggest two different histological patterns in the evolution of pyogranulomas induced by C. pseudotuberculosis, according to the immunological status of the host.

Histological responses during experimental Corynebacterium pseudotuberculosis infection in lambs were investigated in parotid lymph nodes for ten days following inoculation. Lambs were infected by the subcutaneous route into the right eyelid with a virulent strain of C. pseudotuberculosis. Multiple microscopic acute abscesses, predominantly infiltrated with polymorphonuclear (PMN) leucocytes, were seen in the right parotid lymph node on the 1st day post-inoculation (PI). This massive PMN infiltration coincided with a peripheral blood granulocytosis. On day 3 PI, an influx of histiocytes was observed, while the microabscesses became confluent. From day 3 to day 10 PI, these lesions became enlarged and transformed into typical pyogranulomas with a central necrosis and a peripheral mantle of mononuclear cells composed of macrophages, epithelioid cells and lymphocytes; these histological changes were associated with a bacterial dissemination limited to the superficial lymph nodes. A lymphoid hyperplasia with prominent germinal centers was observed in the draining lymph nodes from day 3 PI. These results illustrate the dual role of granulomatous lesions in chronic bacterial infections: although they limit bacterial dissemination, the granulomas do not impair the persistence of infectious organisms in the host, leading to focal tissue damage.