Evaluation of the 3D symmetry of the knees when walking using na ambulatory inertia system: results 14 months after ACL Plasty.

Purpose of the study: Reconstruction of the anterior cruciate ligament (ACL) controls laxity but does not enable restoration of strictly normal 3D kinematics. The purpose of this study was to compare the kinematics of the pathological knee with that of the healthy knee after ACL plasty. This study applied a new ambulatory system using miniature captors. Material and method: Five patients with an isolated injury of the ACL participated in this study. The patients were assessed after injury (T1), at five months (T2), and at 14 months (T3) after surgery. The assessment included laxity (KT-1000), the IKDC score and the Lysholm score. The 3D angles of the knees were measured when walking 30 m on flat ground using a system composed of to small inertia units (3D accelerometer and 3D gyroscope) and a portable recorder. Functional settings were optimised and validating to ensure easy precise measurement of the 3D angles. Symmetry of the two knees was quantified using a symmetry index (SI) (difference in amplitude normalised in relation to mean amplitude) and the correlation coefficient CC. Results: Clinical indicators improved during the follow-up (IKDC T1: 3C, 2C; T2: 5B; T3: 2A, 3B; subjective IKD: 53-95; Lysholm 67-96). Mean laxity improved from 8.6m to 2.5 mm. The gait analysis showed increased symmetry in terms of amplitude for flexion-extension (SI: −17% at T1, −1% at T2, 1% at T3), and an increase in symmetry in terms of the rotation signature (CC: 0.16 at T1, 0.99 at T2, 0.99 at T3). There was no trend to varus-valgus. Discussion: This study demonstrates the clinical application of the new ambulatory system for measuring 3D angles of the knee joint. Joint symmetry increased after ACL plasty but still showed some perturbation at 14 months. The results observed here are in agreement with the literature. Other patients and other types of gait are being analysed. Conclusion: This portable system allows gait analysis outside the laboratory, before and after ACL injury. It is very useful for follow-up after surgery.

Trypanosoma cruzi: Correlations of Biological Aspects of the Life Cycle in Mice and Triatomines

The infection pattern in Swiss mice and Triatomine bugs (Rhodnius neglectus) of eleven clones and the original stock of a Trypanosoma cruzi isolate, derived from a naturally infected Didelphis marsupialis, were biochemically and biologically characterized. The clones and the original isolate were in the same zymodeme (Z1) except that two clones were found to be in zymodeme 2 when tested with G6PDH. Although infective, neither the original isolate nor the clones were highly virulent for the mice and lesions were only observed in mice infected with the original stock and one of the clones (F8). All clones and the original isolate infected bugs well while only the original isolate and clones E2 and F3 yielded high metacyclogenesis rates. An observed correlation between absence of lesions in the mammal host and high metacyclogenesis rates in the invertebrate host suggest a evolutionary trade off i.e. a fitness increase in one trait which is accompanied by a fitness reduction in a different one. Our results suggest that in a species as heterogeneous as T. cruzi, a cooperation effect among the subpopulations should be considered.

Variability of gait patterns during unconstrained walking assessed by satellite positioning (GPS).

It is established that the ratio between step length (SL) and step frequency (SF) is constant over a large range of walking speed. However, few data are available about the spontaneous variability of this ratio during unconstrained outdoor walking, in particular over a sufficient number of steps. The purpose of the present study was to assess the inter- and intra-subject variability of spatio-temporal gait characteristics [SL, SF and walk ratio (WR=SL/SF)] while walking at different freely selected speeds. Twelve healthy subjects walked three times along a 100-m athletic track at: (1). a slower than preferred speed, (2). preferred speed and (3). a faster than preferred speed. Two professional GPS receivers providing 3D positions assessed the walking speed and SF with high precision (less than 0.5% error). Intra-subject variability was calculated as the variation among eight consecutive 5-s samples. WR was found to be constant at preferred and fast speeds [0.41 (0.04) m.s and 0.41 (0.05) m.s respectively] but was higher at slow speeds [0.44 (0.05) m.s]. In other words, between slow and preferred speed, the speed increase was mediated more by a change in SF than SL. The intra-subject variability of WR was low under preferred [CV, coefficient of variation = 1.9 (0.6)%] and fast [CV=1.8 (0.5)%] speed conditions, but higher under low speed condition [CV=4.1 (1.5)%]. On the other hand, the inter-subject variability of WR was 11%, 10% and 12% at slow, preferred and fast walking speeds respectively. It is concluded that the GPS method is able to capture basic gait parameters over a short period of time (5 s). A specific gait pattern for slow walking was observed. Furthermore, it seems that the walking patterns in free-living conditions exhibit low intra-individual variability, but that there is substantial variability between subjects.

Polar gradients of the DYRK-family kinase Pom1 couple cell length with the cell cycle.

Cells normally grow to a certain size before they enter mitosis and divide. Entry into mitosis depends on the activity of Cdk1, which is inhibited by the Wee1 kinase and activated by the Cdc25 phosphatase. However, how cells sense their size for mitotic commitment remains unknown. Here we show that an intracellular gradient of the dual-specificity tyrosine-phosphorylation regulated kinase (DYRK) Pom1, which emanates from the ends of rod-shaped Schizosaccharomyces pombe cells, serves to measure cell length and control mitotic entry. Pom1 provides positional information both for polarized growth and to inhibit cell division at cell ends. We discovered that Pom1 is also a dose-dependent G2-M inhibitor. Genetic analyses indicate that Pom1 negatively regulates Cdr1 and Cdr2, two previously described Wee1 inhibitors of the SAD kinase family. This inhibition may be direct, because in vivo and in vitro evidence suggest that Pom1 phosphorylates Cdr2. Whereas Cdr1 and Cdr2 localize to a medial cortical region, Pom1 forms concentration gradients from cell tips that overlap with Cdr1 and Cdr2 in short cells, but not in long cells. Disturbing these Pom1 gradients leads to Cdr2 phosphorylation and imposes a G2 delay. In short cells, Pom1 prevents precocious M-phase entry, suggesting that the higher medial Pom1 levels inhibit Cdr2 and promote a G2 delay. Thus, gradients of Pom1 from cell ends provide a measure of cell length to regulate M-phase entry.

The tumour suppressor LATS2 interacts with both Signalosome and E3 ubiquitin ligases : implications in control of cell cycle progression

SUMMARY LATS2 is a member of the Lats tumour suppressor gene family. The human LATS2 gene is located at chromosome 13q11-12, which has been shown to be a hot spot (67%) for LOH in nonsmall cell lung cancer. Both lats mosaic flies and LATS1 deficient mice spontaneously develop tumours, an observation that is explained by the function of LATS1 in suppressing tumourigenesis by negatively regulating cell proliferation by modulating Cdc2/Cyclin A activity. LATS1 also plays a critical role in maintenance of ploidy through its action on the spindle assembly checkpoint. Initial insights into the function of LATS2 reveals that the protein is involved in the G2/M transition of the cell cycle, whereby it controls the phosphorylation status of Cdc25C. The aim of the present study was to identify LATS2 interacting partners that would provide a more thorough understanding of the molecular pathways in which the protein is involved. The yeast two-hybrid system identified a number of candidate genes that interact with LATS2. Most of the interactions were confirmed biochemically by GST-pull down assays that enabled us to demonstrate that LATS2 is an integral component of the Signalosome complex. The Signalosome is thought to be required for the establishment of functional Cullin-based E3 ubiquitin ligases, the substrate-recognition elements of the ubiquitin-mediated protein proteolytic pathway. The findings that LATS2 also interacts with all of the components of the E3 enzymes allows us to postulate that LATS2 is probably involved in the regulation of this Signalosome-E3 super-complex. In addition, the discovery that LATS2 associates with multiple protein kinases localised at the cellular membrane and in various signalling cascades supports the idea that LATS2 functions as an integrator of signals which allows it to monitor the activity of these pathways and translate these signals through its action on the Signalosome. Furthermore, the observation that a kinase-dead LATS2 mutant arrests at the G2/M phase of the cell cycle, demonstrates that the protein, through the action of its kinase domain, is crucial for progression through the cell cycle, an action in accordance to its proposed role as a regulator of E3 ubiquitin ligases. The findings presented herein provide evidence that LATS2 associates with the Signalosome-E3 ubiquitin ligases super-complex which governs protein stability. Any alteration of the protein would have a strong impact on pathways that modulate cell proliferation, as shown by its implication in tumourigenesis. RESUME LATS2 est un membre de la famille de gènes suppresseurs de tumeurs LATS. Le gène humain LATS2 est situé sur le chromosome 13q11-12, une région qui s'est avérée être un point sensible (67%) dans la perte d'hétérozigosité (LOH) notamment pour le cancer du poumon. Le fait que des tumeurs se développent spontanément chez les souris qui sont déficientes pour le gène LATS1 ainsi que dans des cellules mutantes pour LATS chez la Drosophile, est expliqué Par la fonction de LATS1, qui est de supprimer l'apparition de tumeurs en réprimant la prolifération cellulaire à travers sa capacité à réguler l'activité de Cdc2/Cyciine A. LATS1 joue également un rôle important au niveau du maintient de la ploïdie de la cellule, au travers de son action sur les points de contrôle de l'assemblage du fuseau mitotique. Les premières études du gène LATS2 indiquent que la protéine est, par son contrôle des réactions de phosphorylation de la Cdc25C, impliquée dans la transition 021M. Le but de cette étude était d'identifier les protéines qui interagissent avec LATS2, en vue d'obtenir une compréhension plus approfondie des mécanismes moléculaires dans lesquels LATS2 se trouve engagée. Le système de double-hybride chez la levure a permis l'identification d'un grand nombre de gènes qui interagissent avec LATS2. La plupart des interactions ont été confirmées par GST «pull clown», une technique in vitro qui a permis de démontrer que LATS2 est un composant intégral du Signalosome. Ce complexe est supposé réguler l'activité des E3 ubiquitine-rigases, les éléments responsables du recrutement des substrats qui doivent être recyclés par la voie de dégradation ubiquitine-dépendante. Les résultats obtenus indiquent également que LATS2 interagit avec tous les composants des enzymes E3, ce qui nous permet de soumettre l'idée selon laquelle la protéine LATS2 est en fait impliquée dans la régulation du complexe Signalosorne-E3. De plus, la découverte que LATS2 se trouve associée à plusieurs protéines kinases localisées au niveau de la membrane cellulaire, ainsi que dans diverses voies de transduction, confirment l'idée que LATS2 fonctionne en tant que molécule qui intègre les signaux en provenance de ces différentes voies cellulaires. De ce fait, il lui serait possible de coordonner la destruction des protéines au moyen du complexe Signalosome, permettant ainsi de réprimer l'activité des voies de signalisation. En outre, l'introduction d'une mutation dans le domaine kinase de LATS2 résulte en l'arrêt du cycle cellulaire en G2/M, ce qui montre que la protéine, au travers de son domaine kinase, est cruciale pour le bon fonctionnement du cycle cellulaire, ceci en accord avec son rôle proposé comme régulateur des E3 ubiquitine-ligases. Les résultats présentés dans ce manuscrit démontrent que la protéine LATS2 se trouve associée au complexe Signalosome-E3 qui régule la dégradation des protéines. La moindre modification de la protéine engendrerait des répercussions importantes au niveau des voies de transduction qui contrôlent fa prolifération ceilulaire, ce qui atteste du rôle déterminant que joue LAT32 dans la tumorigénèse.

Food Security on the island of Ireland: are we sleep walking into a crisis?

IPH has developed a discussion paper on food security on the island. This makes the case that health is and needs to be central to food and agricultural policy. Population health, food systems and agricultural production are intimately linked.  A clear framework on food security is needed in both parts of the island of Ireland and this offers a key opportunity for cooperation. This article has been published in the latest edition of The Journal of Cross Border Studies in Ireland - No 6 launched on 8 March 2011.

Ecology of mosquitoes (Diptera: Culicidae) in areas of Serra do Mar State Park, State of São Paulo, Brazil. III - daily biting rhythms and lunar cycle influence

The ecology of mosquito species (Diptera: Culicidae) was studied in areas of the Serra do Mar State Park, State of São Paulo, Brazil. The influence of the lunar cycle and the daily biting rhythms of mosquito populations were analyzed. Systematized biweekly human bait collections were made in a silvatic environment for 24 consecutive months (January 1991 to December 1992). A total of 20,591 specimens of adult mosquitoes belonging to 55 species were collected from 545 catches. Sabethini species were captured exclusively during daylight periods, with the exception of Trichoprosopon digitatum, while members of Anophelinae predominated during nocturnal hours. Members of the subfamily Culicinae that were collected primary during nocturnal periods included Culex nigripalpus, Coquillettidia chrysonotum and Cq. venezuelensis while daytime catches included Psorophora ferox and Ps. albipes. Others members of culicines mosquitoes that were collected during both day and night included: Aedes serratus, Ae. scapularis and Ae. fulvus. Lunar cycles did not appear to influence the daily biting rhythms of most mosquito species in the area, but larger numbers of mosquitoes were collected during the new moon. Ae. scapularis were captured mainly during the full moon.

Dependence of brain intravoxel incoherent motion perfusion parameters on the cardiac cycle.

Measurement of microvascular perfusion with Intravoxel Incoherent Motion (IVIM) MRI is gaining interest. Yet, the physiological influences on the IVIM perfusion parameters ("pseudo-diffusion" coefficient D*, perfusion fraction f, and flow related parameter fD*) remain insufficiently characterized. In this article, we hypothesize that D* and fD*, which depend on blood speed, should vary during the cardiac cycle. We extended the IVIM model to include time dependence of D* = D*(t), and demonstrate in the healthy human brain that both parameters D* and fD* are significantly larger during systole than diastole, while the diffusion coefficient D and f do not vary significantly. The results non-invasively demonstrate the pulsatility of the brain's microvasculature.

Life cycle and reproductive parameters of Clerada apicicornis signoret (Hemiptera: Lygaeidae) under laboratory conditions

The life cycle of Clerada apicicornis was determined under laboratory conditions. Mean development times in days were: egg 27.2, nymph I 12.5, nymph II 12, nymph III 13.4, nymph IV 16.4, nymph V 26. The life expectancy of adults ranged from 117 to 317 days (mean 196 days). Based on a cohort of 29 females of C. apicicornis, a horizontal life table was constructed. The following predictive parameters were obtained: net rate of reproduction (Ro = 48.31), intrinsic rate of population increase (r m = 0.153), generation time (Tc = 28.20 weeks), and finite rate of population increment (lambda = 1.16). The reproductive value (Vx) for each age class of the cohort females was calculated. The following observed parameters were calculated after mortality in each stage: net rate of reproduction (R'o=13.4), intrinsic rate of population increase (r c' =0.09 ), and finite rate of population increment (lambda' =1.1). The generation time (Tc' =27.4) was estimated using the methods of Laughlin and Bengstron. A vertical life table was elaborated and mortality was described for one generation of the cohort.

Characteristics of the bological cycle of Lutzomyia evandroi Costa Lima & Antunes, 1936 (Diptera: Psychodidae) under experimental conditions

Lutzomyia evandroi Costa Lima and Antunes, 1936 is found in Rio Grande do Norte, northeastern Brazil, in areas of visceral and mucocutaneous leishmaniasis and follows the same geographic distribution of L. longipalpis. The biological cycle, oviposition, morphological and behavioral characteristics of the species were studied under experimental conditions. The average number of eggs per wild caught female varied from 21 to 50 eggs along the year, with a peak occurring between January and March and another in August, with oviposition lasting for 4 to 12 days. The mean larval phase was 24 days. Ovipositing rates were influenced by rainfall and temperature indexes, with an increase of eggs per oviposition at the beginning and at the end of the rainy season, and a decrease at the peak of the rainy season.

Long-term health-related quality of life and walking capacity of lung recipients with and without bronchiolitis obliterans syndrome.

BACKGROUND: Outcome after lung transplantation (LTx) is affected by the onset of bronchiolitis obliterans syndrome (BOS) and lung function decline. Reduced health-related quality of life (HRQL) and physical mobility have been shown in patients developing BOS, but the impact on the capacity to walk is unknown. We aimed to compare the long-term HRQL and 6-minute walk test (6MWT) between lung recipients affected or not by BOS Grade > or =2. METHODS: Fifty-eight patients were prospectively followed for 5.6 +/- 2.9 years after LTx. Assessments included the St George's Respiratory Questionnaire (SGRQ) and the 6MWT, which were performed yearly. Moreover, clinical complications were recorded to estimate the proportion of the follow-up time lived without clinical intercurrences after transplant. Analyses were performed using adjusted linear regression and repeated-measures analysis of variance. RESULTS: BOS was a significant predictor of lower SGRQ scores (p < 0.01) and reduced time free of clinical complications (p = 0.001), but not of 6MWT distance (p = 0.12). At 7 years post-transplant, results were: 69.0 +/- 21.8% vs 86.9 +/- 5.6%, p < 0.05 (SGRQ); 58.5 +/- 21.6% vs 88.7 +/- 11.4%, p < 0.01 (proportion of time lived without clinical complications); and 82.2 +/- 10.9% vs 91.9 +/- 14.2%, p = 0.27 (percent of predicted 6MWT), respectively, for patients with BOS and without BOS. CONCLUSIONS: Despite significantly less time lived without clinical complications and progressive decline of self-reported health status, the capacity to walk of patients affected by BOS remained relatively stable over time. These findings may indicate that the development of moderate to severe BOS does not prevent lung recipients from walking independently and pursuing an autonomous life.

Aspects of the Maintenance of the Life Cycle of Fasciola hepatica in Lymnaea columella in Minas Gerais, Brazil

Fascioliasis is a parasitic disease of domestic ruminants that occurs worldwide. The lymnaeid intermediate hosts of Fasciola hepatica include Lymnaea columella, which is widely distributed in Brazil. A colony of L. columella from Belo Horizonte, MG, was reared in our laboratory to be used in studies of the F. hepatica life cycle, the intermediate host-parasite relationship and development of an anti-helminthic vaccine. In the first experiment 1,180 snails were exposed to miracidia of F. hepatica eggs removed from the biliary tracts of cattle from the State of Rio Grande do Sul. In the second and third experiments the snails were exposed to miracidia that had emerged from F. hepatica eggs from Uruguay, maintained in rabbits. The rates of infection in the first, second and third experiments were 0, 42.1 and 0% respectively. Over 15,806 metacercariae were obtained and stored at 4ºC. Four rabbits weighing 1.5 kg each were infected with 32-44 metacercariae and two with 200. Three rabbits begin to eliminate eggs of the parasite in the feces from 84 days after infection onwards. The biological cycle of F. hepatica in L. columella and the rabbit was completed within 124 days.