Effects of knee surgery on cardiac function in soccer players

OBJECTIVE: To evaluate the effects of knee surgery on hematocrit and hemoglobin concentration and on resting cardiac parameters as measured by echocardiography. DESIGN: Ten soccer players who underwent knee surgery were evaluated before (T1) and after (T2) hospitalization within a 7-day interval. RESULTS: After hospitalization, end diastolic volume and stroke volume were significantly reduced (P < 0.05) by 14 and 22%, respectively. Despite a significant increase in resting heart rate (T1: 68 +/- 3.3 beats/ min, T2: 72 +/- 3.1 beats/min, P < 0.05), cardiac output was significantly decreased (T1: 4.89 +/- 0.56 liters/min; 3.95 +/- 0.62 liters/min, P < 0.05). The ejection fraction was 65% at T1 and fell to 58% at T2 (P < 0.05). After hospitalization, significant decreases in hemoglobin concentration and hematocrit were observed, suggesting a fall in blood volume. CONCLUSION: In soccer players, knee surgery leads to resting cardiac deconditioning, which is characterized by a significant reduction in stroke volume.     

Large spectrum of lissencephaly and pachygyria phenotypes resulting from de novo missense mutations in tubulin alpha 1A (TUBA1A)

We have recently reported a missense mutation in exon 4 of the tubulin alpha 1A (Tuba1a) gene in a hyperactive N-ethyl-N-nitrosourea (ENU) induced mouse mutant with abnormal lamination of the hippocampus. Neuroanatomical similarities between the Tuba1a mutant mouse and mice deficient for Doublecortin (Dcx) and Lis1 genes, and the well-established functional interaction between DCX and microtubules (MTs), led us to hypothesize that mutations in TUBA1A (TUBA3, previous symbol), the human homolog of Tuba1a, might give rise to cortical malformations. This hypothesis was subsequently confirmed by the identification of TUBA1A mutations in two patients with lissencephaly and pachygyria, respectively. Here we report additional TUBA1A mutations identified in six unrelated patients with a large spectrum of brain dysgeneses. The de novo occurrence was shown for all mutations, including one recurrent mutation (c.790C>T, p.R264C) detected in two patients, and two mutations that affect the same amino acid (c.1205G>A, p.R402H; c.1204C>T, p.R402C) detected in two other patients. Retrospective examination of MR images suggests that patients with TUBA1A mutations share not only cortical dysgenesis, but also cerebellar, hippocampal, corpus callosum, and brainstem abnormalities. Interestingly, the specific high level of Tuba1a expression throughout the period of central nervous system (CNS) development, shown by in situ hybridization using mouse embryos, is in accordance with the brain-restricted developmental phenotype caused by TUBA1A mutations. All together, these results, in combination with previously reported data, strengthen the relevance of the known interaction between MTs and DCX, and highlight the importance of the MTs/DCX complex in the neuronal migration process.     

Germline-encoded recognition of diverse glycolipids by natural killer T cells

Natural killer T cells expressing 'invariant' T cell receptor alpha-chains (TCRalpha chains) containing variable (V) and joining (J) region V(alpha)14-J(alpha)18 (V(alpha)14i) rearrangements recognize both endogenous and microbial glycolipids in the context of CD1d. How cells expressing an invariant TCRalpha chain and a restricted set of TCRbeta chains recognize structurally diverse antigens is not clear. Here we show that a V(alpha)14i TCR recognized many alpha-linked glycolipids by means of a 'hot-spot' of germline-encoded amino acids in complementarity-determining regions 3alpha, 1alpha and 2beta. This hot-spot did not shift during the recognition of structurally distinct antigens, suggesting that the V(alpha)14i TCR functions as a pattern-recognition receptor, conferring on natural killer T cells the ability to sense and respond in an innate way to pathogens displaying antigenic alpha-linked glycolipids.     

The use of physical hydrogels of chitosan for skin regeneration following third-degree burns

Skin repair is an important field of the tissue engineering, especially in the case of extended third-degree burns, where the current treatments are still insufficient in promoting satisfying skin regeneration. Bio-inspired bi-layered physical hydrogels only constituted of chitosan and water were processed and applied to the treatment of full-thickness burn injuries. The aim of the study was at assessing whether this material was totally accepted by the host organism and allowed in vivo skin reconstruction of limited area third-degree burns. A first layer constituted of a rigid protective gel ensured good mechanical properties and gas exchanges. A second soft and flexible layer allowed the material to follow the geometry of the wound and ensured a good superficial contact. To compare, highly viscous solutions of chitosan were also considered. Veterinary experiments were performed on pig's skins and biopsies at days 9, 17, 22, 100 and 293, were analysed by histology and immuno-histochemistry. Only one chitosan material was used for each time. All the results showed that chitosan materials were well tolerated and promoted a good tissue regeneration. They induced inflammatory cells migration and angiogenetic activity favouring a high vascularisation of the neo-tissue. At day 22, type I and IV collagens were synthesised under the granulation tissue and the formation of the dermal-epidermal junction was observed. After 100 days, the new tissue was quite similar to a native skin, especially by its aesthetic aspect and its great flexibility.     

Molecular characterization of measles virus circulating in the Indian Ocean Islands during 2005-2006 and in France in 2006

Despite the availability of safe and immunogenic vaccines, measles still causes significant morbidity and mortality especially in Africa. In this study, two measles outbreaks in the Indian Ocean Islands; Mayotte in 2005-2006 and Seychelles in 2006 were studied. Nasopharyngeal swabs, urine and/or blood samples were collected from patients with clinically diagnosed measles. Measles viruses were isolated in four cases from patients in Mayotte. Measles strains circulating in both outbreaks were determined to be genotype D4 when compared to the WHO reference strains. During this time, measles virus was isolated from patients in France and they were also found to belong to the same genotype. The viruses clustered into two distinct D4 subgroups; The Indian Ocean strains were similar to the Montreal-subgroup, whereas the French strains associated with the Johannesburg-subgroup. The Indian Ocean strains formed a homogeneous group. They shared four specific amino acids in the 3' region of the N gene and two amino acids in the H gene, which differed from other genotype D4 viruses. This suggests that the same measles lineage circulated in Mayotte and Seychelles. Sequence comparison of the French isolates with other measles strains showed that they were more closely related to strains circulating in Germany in 2005, which had their origin in Romania. This study provides the baseline for molecular epidemiology of measles virus in Mayotte and Seychelles. The knowledge of circulating measles virus will help in documenting measles elimination program. This report also highlights the fact that progress of measles elimination is blighted continually by the phenomenon of measles importation.     

Innate immunity, assessed by plasma NO measurements, is not suppressed during the incubation fast in eiders

Immunity is hypothesized to share limited resources with other physiological functions and may mediate life history trade-offs, for example between reproduction and survival. However, vertebrate immune defense is a complex system that consists of three components. To date, no study has assessed all of these components for the same animal model and within a given situation. Previous studies have determined that the acquired immunity of common eiders (Somateria mollissima) is suppressed during incubation. The present paper aims to assess the innate immune response in fasting eiders in relation to their initial body condition. Innate immunity was assessed by measuring plasma nitric oxide (NO) levels, prior to and after injection of lipopolysaccharides (LPS), a method which is easily applicable to many wild animals. Body condition index and corticosterone levels were subsequently determined as indicators of body condition and stress level prior to LPS injection. The innate immune response in eiders did not vary significantly throughout the incubation period. The innate immune response of eiders did not vary significantly in relation to their initial body condition but decreased significantly when corticosterone levels increased. However, NO levels after LPS injection were significantly and positively related to initial body condition, while there was a significant negative relationship with plasma corticosterone levels. Our study suggests that female eiders preserve an effective innate immune response during incubation and this response might be partially determined by the initial body condition.     

Calcium-deficient apatite synthesized by ammonia hydrolysis of dicalcium phosphate dihydrate: influence of temperature, time, and pressure

In this work, calcium-deficient apatites (CDA) were synthesized by ammonia hydrolysis reaction of dicalcium phosphate dihydrate (DCPD; CaHPO4 x 2 H2O) to obtain biphasic calcium phosphates (BCP) without any extraionic substitution. The influence of three parameters was studied: temperature of the reaction (70 and 100 degrees C), time of the reaction (4 and 18 h), and the pressure (open and closed system). Experiments were made according to a factorial design method (FDM) allowing optimization of the number of samples as well as statistical analysis of results. Moreover, the influence of temperature (until 200 degrees C) was investigated. The crystal size of CDA was determined according to the Scherrer's formula and from Rietveld refinements taking the CDA anisotropy into account. The last method seems to be a reliable method to determine crystallite sizes of CDA, since crystallite sizes of CDA along <00l> and directions were accessible. The results describe the hydroxyapatite % (HA%) in BCP by a first-order polynomial equation in the experimental area studied and the HA content was found to increase by raising time and temperature of the reaction. Moreover, the type of reaction system (open/closed vessel) appeared to have little influence on HA%.     

Retinal degenerations: from cell signaling to cell therapy; pre-clinical and clinical issues

Extracellular signaling molecules have been implicated in the progression of Retinal Degeneration (RD). Gene regulatory events linked to the maintenance of retinal structure and function incorporate signaling cascades that may serve as therapeutic targets for some forms of blindness. This review shall focus on the evidence for non-cell-autonomous mechanisms that affect the pattern of degeneration seen in retinal dystrophies, the types of signals that may influence the course of degeneration and finally with the related prospects for retinal-therapies.