The Impact of Prior Season Vaccination on Subsequent Influenza Vaccine Effectiveness to Prevent Influenza-related Hospitalizations Over 4 Influenza Seasons in Canada.

BACKGROUND: Recent studies have demonstrated the possibility of negative associations between prior influenza vaccines and subsequent influenza vaccine effectiveness (VE), depending on season and strain. We investigated this association over 4 consecutive influenza seasons (2011-2012 through 2014-2015) in Canada. METHODS: Using a matched test-negative design, laboratory-confirmed influenza cases and matched test-negative controls admitted to hospitals were enrolled. Patients were stratified into 4 groups according to influenza vaccine history (not vaccinated current and prior season [referent], vaccinated prior season only, vaccinated current season only, and vaccinated both current and prior season). Conditional logistic regression was used to estimate VE; prior vaccine impact was assessed each season for overall effect and effect stratified by age (<65 years, ≥65 years) and type/subtype (A/H1N1, A/H3N2, influenza B). RESULTS: Overall, mainly nonsignificant associations were observed. Trends of nonsignificant decreased VE among patients repeatedly vaccinated in both prior and current season relative to the current season only were observed in the A/H3N2-dominant seasons of 2012-2013 and 2014-2015. Conversely, in 2011-2012, during which B viruses circulated, and in 2013-2014, when A/H1N1 circulated, being vaccinated in both seasons tended to result in a high VE in the current season against the dominant circulating subtype. CONCLUSIONS: Prior vaccine impact on subsequent VE among Canadian inpatients was mainly nonsignificant. Even in circumstances where we observed a trend of negative impact, being repeatedly vaccinated was still more effective than not receiving the current season's vaccine. These findings favor continuation of annual influenza vaccination recommendations, particularly in older adults. CLINICAL TRIALS REGISTRATION: NCT01517191.

Type 1 primary hyperoxaluria: A case report and focus on bone impairment of systemic oxalosis.

Primary hyperoxaluria is a rare genetic disorder characterized by oxalate overproduction, leading to kidney failure due to nephrocalcinosis, and is eventually responsible for systemic oxalosis. Bone impairment, secondary to oxalate deposits, is one of the many complications that may occur. Skeletal involvement can be difficult to diagnose because of lack of clinical symptoms and therefore needs to be confirmed by invasive testing, such as transiliac bone biopsy. If confirmed, bone oxalosis is the proof of disease severity and that combined liver-kidney transplantation should be performed.

Interim estimates of 2013/14 influenza clinical severity and vaccine effectiveness in the prevention of laboratory-confirmed influenza-related hospitalisation, Canada, February 2014.

During the 2013/14 influenza season in Canada, 631 of 654 hospitalisations for laboratory-confirmed influenza enrolled in sentinel hospitals were due to Influenza A. Of the 375 with known subtype, influenza A(H1N1) accounted for 357. Interim unmatched vaccine effectiveness adjusted for age and presence of one or more medical comorbidities was determined by test-negative case-control design to be 58.5% (90% confidence interval (CI): 43.9-69.3%) overall and 57.9% (90% CI: 37.7-71.5) for confirmed influenza A(H1N1).

Bone mineralization: from tissue to crystal in normal and pathological contexts.

Bone is a complex and structured material; its mechanical behavior results from an interaction between the properties of each level of its structural hierarchy. The degree of mineralization of bone (bone density measured at tissue level) and the characteristics of the mineral deposited (apatite crystals) are major determinants of bone strength. Bone remodeling activity acts as a regulator of the degree of mineralization and of the distribution of mineral at the tissue level, directly impacting bone mechanical properties. Recent findings have highlighted the need to understand the underlying process occurring at the nanostructure level that may be independent of bone remodeling itself. A more global comprehension of bone qualities will need further works designed to characterize what are the consequences on whole bone strength of changes at nano- or microstructure levels relative to each other.

Effects of strontium on the quality of bone apatite crystals: a paired biopsy study in postmenopausal osteoporotic women.

UNLABELLED: In paired biopsies of osteoporotic women treated with either strontium ranelate or a placebo for 36 months, characteristics of bone apatite crystals were not influenced by the presence of strontium. The mean rate of substitutions of calcium by strontium ions was 4.5 %. INTRODUCTION: The potential effect of strontium (Sr) on bone apatite crystals was investigated in paired biopsies of osteoporotic women treated with either strontium ranelate (SrRan) or a placebo for 36 months. METHODS: In ten paired biopsies, crystallinity, apparent length and width/thickness of crystals, interplanar distances, and lattice parameters of unit cells were assessed by X-ray diffraction and selected area electron diffraction. RESULTS: All these parameters, reflecting crystal and unit cell characteristics, were not influenced by the presence of Sr and were similar in SrRan and placebo groups after 36 months of treatment. The mean rate of substitutions of calcium by Sr ions was 4.5 %. CONCLUSION: Overall, the quality of bone apatite crystals was maintained after 36 months of treatment with SrRan.

Transforming growth factor-beta 3 is required for secondary palate fusion.

Mice lacking TGF-beta 3 exhibit an incompletely penetrant failure of the palatal shelves to fuse leading to cleft palate. The defect appears to result from impaired adhesion of the apposing medial edge epithelia of the palatal shelves and subsequent elimination of the mid-line epithelial seam. No craniofacial abnormalities were observed. This result demonstrates that TGF-beta 3 affects palatal shelf fusion by an intrinsic, primary mechanism rather than by effects secondary to craniofacial defects.

Cross-reactive antibody to swine influenza A(H3N2) subtype virus in children and adults before and after immunisation with 2010/11 trivalent inactivated influenza vaccine in Canada, August to November 2010.

In pre- and post-immunisation sera from children (17-120 months-old) and adults (20-59 years-old) immunised with 2010/11 trivalent inactivated influenza vaccine, we assessed age-related patterns of sero-susceptibility and vaccine-induced cross-reactive antibodies to a representative swine H3N2 (swH3N2) and a related ancestral human H3N2 (A/Sydney/5/1997) influenza virus. Few children but a greater proportion of adults showed pre-immunisation haemagglutination inhibition titres ≥40 to either virus. Titres increased with age among children but decreased in adults. Fewer than 20% showed a four-fold rise in antibody titres to either virus following immunisation. Further investigation is warranted to guide ongoing risk assessment and response to emerging swine H3N2 viruses.

Fibroblast growth factor 2 control of vascular tone.

Vascular tone control is essential in blood pressure regulation, shock, ischemia-reperfusion, inflammation, vessel injury/repair, wound healing, temperature regulation, digestion, exercise physiology, and metabolism. Here we show that a well-known growth factor, FGF2, long thought to be involved in many developmental and homeostatic processes, including growth of the tissue layers of vessel walls, functions in vascular tone control. Fgf2 knockout mice are morphologically normal and display decreased vascular smooth muscle contractility, low blood pressure and thrombocytosis. Following intra-arterial mechanical injury, FGF2-deficient vessels undergo a normal hyperplastic response. These results force us to reconsider the function of FGF2 in vascular development and homeostasis in terms of vascular tone control.

A new concept of gentamicin loaded HAP/TCP bone substitute for prophylactic action: in vivo pharmacokinetic study.

Despite systemic prophylaxis, infection rates after orthopedic surgery can reach more than 1%. A new HAP/TCP bone substitute loaded with 125 mg of gentamicin was designed for prophylactic use. Its aim was to enhance the efficacy of systemic prophylactic treatments by increasing the local antibiotic concentration. The release rate of gentamicin from the bone substitute was investigated after implantation in the femoral condyle of five sheep. In order to investigate the local and systemic gentamicin concentrations, synovial fluids and blood samples were assessed over a 5-day period. The mean gentamicin concentration peak in blood was 4.2 µg/ml and the mean local concentration in synovial fluids during the first 8 h was 305 µg/ml. After 48 h, the concentrations in blood and synovial fluids were less than 0.5 µg/ml. No remaining gentamicin was detected in bone substitutes explanted after 8 days of implantation. The gentamicin release rate from the bone substitutes assessed corresponds to the recommendations for the prophylactic use of antibiotics: high local concentration but limited in time (less than 48 h) not to select antibiotic-resistant bacterial strains. Our results indicated that this implant should be an effective prophylactic tool in orthopedic surgery in combination with systemic prophylaxis.

Intrinsic properties of osteomalacia bone evaluated by nanoindentation and FTIRM analysis.

Osteomalacia is a pathological bone condition consisting in a deficient primary mineralization of the matrix, leading to an accumulation of osteoid tissue and reduced bone mechanical strength. The amounts, properties and organization of bone constituents at tissue level, are known to influence its mechanical properties. It is then important to investigate the relationship between mechanical behavior and tissue composition at this scale in order to provide a better understanding of bone fragility mechanisms associates with this pathology. Our purpose was to analyze the links between ultra-structural properties and the mechanical behavior of this pathological bone tissue (osteomalacia) at tissue level (mineral and osteoid separately, or global). Four bone biopsies were taken from patients with osteomalacia, and subsequently embedded, sectioned, and polished. Then nanoindentation tests were performed to determine local elastic modulus E, contact hardness Hc and true hardness H for both mineralized and organic bone phases and for the global bone. The creep of the bone was also studied using a special indentation procedure in order to assess visco-elasto-plastic (creep) bone behavior. This allowed a detailed study of the rheological models adapted to the bone and to calculate the parameters associated to a Burgers model. Ultra-structural parameters were measured by Fourier Transform InfraRed Microspectroscopy (FTIRM) on the same position as the indents. The use of rheological models confirmed a significant contribution from the organic phase on the viscous character of bone tissue. The elastic E and the elasto-plastic Hc deformation were correlated to both collagen maturity and Mineral/Matrix. The pure plastic deformation H was only correlated to the mineral phase. Our data show that mineral phase greatly affects mechanical variables (moduli and viscosities) and that organic phase (as illustrated in osteoid tissue) may play an important role in the creep behavior of bone. In conclusion, this study brings mechanical and physicochemical values for osteoid and mineral phases.

In osteoporotic women treated with strontium ranelate, strontium is located in bone formed during treatment with a maintained degree of mineralization.

UNLABELLED: In postmenopausal osteoporotic women and up to 3 years of treatment with strontium ranelate, strontium was present only in recently deposited bone tissue resulting from formation activity during the period of treatment. Strontium was shown to be dose-dependently deposited into this newly formed bone with preservation of the mineralization. INTRODUCTION: Interactions between strontium (Sr) and bone mineral and its effects on mineralization were investigated in women treated with strontium ranelate. METHODS: Bone biopsies from osteoporotic women were obtained over 5-year strontium ranelate treatment from phases II and III studies. Bone samples obtained over 3-year treatment were investigated by X-ray microanalysis for bone Sr uptake and focal distribution, and by quantitative microradiography for degree of mineralization. On some samples, Sr distribution (X-ray cartography) was analyzed on whole sample surfaces and the percentage of bone surface containing Sr was calculated. Bone Sr content was chemically measured on whole samples. RESULTS: In treated women, Sr was exclusively present in bone formed during treatment; Sr deposition depended on the dose with higher focal content in new bone structural units than in old ones constantly devoid of Sr, even after 3-year treatment. A plateau in global bone Sr content was reached after 3 years of treatment. Cartography illustrated the extent of surfaces containing Sr, and formation activity during strontium ranelate treatment was higher in cancellous than in cortical bone. Mineralization was maintained during treatment. CONCLUSION: The quality of bone mineral was preserved after treatment with strontium ranelate, supporting the safety of this agent at the bone tissue level.

Validation of the Seegene RV15 multiplex PCR for the detection of influenza A subtypes and influenza B lineages during national influenza surveillance in hospitalized adults.

Background. The Serious Outcomes Surveillance Network of the Canadian Immunization Research Network (CIRN SOS) has been performing active influenza surveillance since 2009 (ClinicalTrials.gov identifier: NCT01517191). Influenza A and B viruses are identified and characterized using real-time reverse-transcriptase polymerase chain reaction (RT-PCR), and multiplex testing has been performed on a subset of patients to identify other respiratory virus aetiologies. Since both methods can identify influenza A and B, a direct comparison was performed.Methods. Validated real-time RT-PCRs from the World Health Organization (WHO) to identify influenza A and B viruses, characterize influenza A viruses into the H1N1 or H3N2 subtypes and describe influenza B viruses belonging to the Yamagata or Victoria lineages. In a subset of patients, the Seeplex RV15 One-Step ACE Detection assay (RV15) kit was also used for the detection of other respiratory viruses.Results. In total, 1111 nasopharyngeal swabs were tested by RV15 and real-time RT-PCRs for influenza A and B identification and characterization. For influenza A, RV15 showed 98.0 % sensitivity, 100 % specificity and 99.7 % accuracy. The performance characteristics of RV15 were similar for influenza A subtypes H1N1 and H3N2. For influenza B, RV15 had 99.2 % sensitivity, 100 % specificity and 99.8 % accuracy, with similar assay performance being shown for both the Yamagata and Victoria lineages.Conclusions. Overall, the detection of circulating subtypes of influenza A and lineages of influenza B by RV15 was similar to detection by real-time RT-PCR. Multiplex testing with RV15 allows for a more comprehensive respiratory virus surveillance in hospitalized adults, without significantly compromising the reliability of influenza A or B virus detection.

Calcineurin deficiency decreases inflammatory lesions in transforming growth factor beta1-deficient mice.

Transforming growth factor (TGF) beta1) is an immunoregulatory cytokine involved in self-tolerance and lymphocyte homeostasis. Tgfb1 knock-out (KO) mice develop severe multi-focal autoimmune inflammatory lesions due to [Ca(2+)]i deregulation in T cells, and die within 3 weeks after birth. Because the calcineurin inhibitor FK506 inhibits the hyperresponsiveness of Tgfb1(-/-) thymocytes, and because calcineurin Abeta (CNAbeta)-deficient mice do not reject allogenic tumours, we have generated Tgfb1(-/-) Cnab(-/-) mice to address whether CNAbeta deficiency prevents T cell activation and inflammation in Tgfb1(-/-) mice. Here we show that in Tgfb1(-/-) Cnab(-/-) mice inflammation is reduced significantly relative to that in Tgfb1(-/-) mice. However, both CD4(+) and CD8(+) T cells in double knock-out (DKO) mice are activated, as revealed by up-regulation of CD11a lymphocyte function-associated antigen-1 (LFA-1), CD44 and CD69 and down-regulation of CD62L. These data suggest that deficiency of CNAbeta decreases inflammatory lesions but does not prevent activation of autoreactive T cells. Also Tgfb1(-/-) T cells can undergo activation in the absence of CNAbeta, probably by using the other isoform of calcineurin (CNAalpha) in a compensatory manner. CNAbeta-deficient T cells undergo spontaneous activation in vivo and are activated upon anti-T cell receptor stimulation in vitro. Understanding the role of calcineurin in T cell regulation should open up new therapeutic opportunities for inflammation and cancer.

Bone remodeling and bone matrix quality before and after menopause in healthy women.

Acceleration of remodeling activity after menopause leads to bone loss and fragility, however, whether this is associated with modifications of bone matrix quality has been less studied. The impact of variation in bone remodeling rate on bone matrix has been studied mainly in pathologies or anti-osteoporotic treatments. However, in healthy women this has been less studied. We analyzed, at the global level, bone matrix quality in bone biopsies from 3 groups of healthy women (20 per group): 1) before menopause (PreM), 2) 1 year after menopause (PostM, paired biopsies with preM), and 3) 14 (±9) years after menopause (LT-PostM). The mean degree of mineralization (DMB) and heterogeneity index (HI) of mineralization were assessed by X-ray microradiography on whole bone matrix; intrinsic properties (mineral/organic ratio, mineral maturity, mineral crystallinity, collagen maturity) were assessed by Fourier Transform Infrared microspectroscopy, microhardness by microindentation, both at a global level and calculated by mean of several measurements over the whole tissue area. In PostM compared to PreM (bone remodeling rate had doubled), mean DMB measured on the entire bone plane (whole bone matrix) of the sample was not different. HI was increased in trabecular bone indicating a higher heterogeneity of mineralization. However, in PostM, mineral/organic ratio (trabecular) and microhardness (cortical and trabecular) were decreased, whereas mineral/collagen maturation or crystal size/perfection were unchanged. Thus, in PostM, the local mineral content and microhardness were first affected. In LT-PostM (bone remodeling rate was 3 times higher), the mean DMB was still not different. However, the mineral/organic ratio, microhardness, mineral maturity, crystallinity all were lower compared to PreM and PostM, in both cortical and trabecular bone. Bone remodeling rate was negatively correlated with microhardness, DMB, mineral/organic and crystallinity. This suggests that increases in bone remodeling rates after menopause have a direct impact on bone quality by inducing the formation of more extensive "immature" bone areas, but the amount of immature bone does not cause modification of the global DMB.

The role of mineralization and organic matrix in the microhardness of bone tissue from controls and osteoporotic patients.

Degree of mineralization of bone (DMB) is a major intrinsic determinant of bone strength at the tissue level but its contribution to the microhardness (Vickers indentation) at the intermediary level of organization of bone tissue, i.e., Bone Structural Units (BSUs), has never been assessed. The purpose of this study was to analyze the relationship between the microhardness, the DMB and the organic matrix, measured in BSUs from human iliac bone biopsies. Iliac bone samples from controls and osteoporotic patients (men and women), embedded in methyl methacrylate, were used. Using a Vickers indenter, microhardness (kg/mm2) was measured, either globally on surfaced blocks or focally on 100 microm-thick sections from bone samples (load of 25 g applied during 10 sec; CV=5%). The Vickers indenter was more suited than the Knoop indenter for a tissue like bone in which components are diversely oriented. Quantitative microradiography performed on 100 microm-thick sections, allowed measurement of parameters reflecting the DMB (g/cm3). Assessed on the whole bone sample, both microhardness and DMB were significantly lower (-10% and -7%, respectively) in osteoporotic patients versus controls (p<0.001). When measured separately at the BSU level, there were significant positive correlations between microhardness and DMB in controls (r2=0.36, p<0.0001) and osteoporotic patients (r2=0.43, p<0.0001). Mineralization is an important determinant of the microhardness, but did not explain all of its variance. To highlight the role of the organic matrix in bone quality, microhardness of both osteoid and adjacent calcified matrix were measured in iliac samples from subjects with osteomalacia. Microhardness of organic matrix is 3-fold lower than the microhardness of calcified tissue. In human calcanei, microhardness was significantly correlated with DMB (r2=0.33, p=0.02) and apparent Young's modulus (r2=0.26, p=0.03). In conclusion, bone microhardness measured by Vickers indentation is an interesting methodology for the evaluation of bone strength and its determinants at the BSU level. Bone microhardness is linked to Young's modulus of bone and is strongly correlated to mineralization, but the organic matrix accounts for about one third of its variance.

Ablation of the murine alpha myosin heavy chain gene leads to dosage effects and functional deficits in the heart.

The alpha-myosin heavy chain (alpha-MyHC) is the major contractile protein expressed in the myocardium of adult mice. We have produced mice carrying a null mutation of alpha-MyHC by homologous recombination in murine ES cells. Homozygous null animals die between 11 and 12 d in utero of gross heart defects, while alpha-MyHC+/- heterozygotes survive and appear externally normal. The presence of a single functional alpha-MyHC+ allele in heterozygous animals results in reduced levels of the transcript and protein as well as fibrosis and alterations in sarcomeric structure. Examination of heart function using a working heart preparation revealed severe impairment of both contractility and relaxation in a subset of the alpha-MyHC+/- animals. Thus, two alpha-MyHC+ alleles are necessary for normal cardiac development, and hemizygosity for the normal allele can result in altered cardiac function.

Targeted disruption of the murine Na+/H+ exchanger isoform 2 gene causes reduced viability of gastric parietal cells and loss of net acid secretion.

Multiple isoforms of the Na+/H+ exchanger (NHE) are expressed at high levels in gastric epithelium, but the physiological role of individual isoforms is unclear. To study the function of NHE2, which is expressed in mucous, zymogenic, and parietal cells, we prepared mice with a null mutation in the NHE2 gene. Homozygous null mutants exhibit no overt disease phenotype, but the cellular composition of the oxyntic mucosa of the gastric corpus is altered, with parietal and zymogenic cells reduced markedly in number. Net acid secretion in null mutants is reduced slightly relative to wild-type levels just before weaning and is abolished in adult animals. Although mature parietal cells are observed, and appear morphologically to be engaged in active acid secretion, many of the parietal cells are in various stages of degeneration. These results indicate that NHE2 is not required for acid secretion by the parietal cell, but is essential for its long-term viability. This suggests that the unique sensitivity of NHE2 to inhibition by extracellular H+, which would allow upregulation of its activity by the increased interstitial alkalinity that accompanies acid secretion, might enable this isoform to play a specialized role in maintaining the long-term viability of the parietal cell.

Mouse model of a familial hypertrophic cardiomyopathy mutation in alpha-tropomyosin manifests cardiac dysfunction.

To investigate the functional consequences of a tropomyosin (TM) mutation associated with familial hypertrophic cardiomyopathy (FHC), we generated transgenic mice that express mutant alpha-TM in the adult heart. The missense mutation, which results in the substitution of asparagine for aspartic acid at amino acid position 175, occurs in a troponin T binding region of TM. S1 nuclease mapping and Western blot analyses demonstrate that increased expression of the alpha-TM 175 transgene in different lines causes a concomitant decrease in levels of endogenous alpha-TM mRNA and protein expression. In vivo physiological analyses show a severe impairment of both contractility and relaxation in hearts of the FHC mice, with a significant change in left ventricular fractional shortening. Myofilaments that contain alpha-TM 175 demonstrate an increased activation of the thin filament through enhanced Ca2+ sensitivity of steady-state force. Histological analyses show patchy areas of mild ventricular myocyte disorganization and hypertrophy, with occasional thrombi formation in the left atria. Thus, the FHC alpha-TM transgenic mouse can serve as a model system for the examination of pathological and physiological alterations imparted through aberrant TM isoforms.

Age-related changes in the biomechanics of healing patellar tendon.

By 2030, there will be 70 million people in the United States over the age of 65, and by 2050, 22% of the US population will be considered elderly. It is generally believed that injuries in the elderly heal slower and less completely than in adolescents or young adults. To evaluate aging effects on tissue repair a surgical injury was created in the middle third of one patellar tendon in 1- and 4-5-year-old New Zealand White rabbits. The biomechanical properties of the isolated repair tissues and contralateral normal tendon tissues were compared at 6, 12 and 26 weeks post-injury. We hypothesized that repair tissues would exhibit age-related reductions in biomechanical properties at all time intervals of healing, both based on raw data and when normalized to values from contralateral tendons. Repairs from both age groups were similar, with no significant increase in maximum stress, strain at maximum stress, or modulus between 6 and 12 weeks. At 26 weeks, the repairs in the 4-year-old rabbits had higher maximum stress values than repairs in the 1-year-old rabbits (p=0.03). There were no significant differences in the strain at maximum stress or modulus. When repair tissue properties were normalized to values in the contralateral normal tendon, the maximum stress of the patellar tendon repair tissue from the 4 year old was significantly greater than the corresponding value from the 1 year old at the 26 week time point (p=0.04). In conclusion, these findings do not support the presence of age-related declines in the biomechanics of healing tendon.

Transforming growth factor beta1 suppresses nonmetastatic colon cancer at an early stage of tumorigenesis.

The transforming growth factor beta (TGF-beta) pathway is known to play an important role in both human and urine colon cancer. However, the staging, ligand specificity, and mechanism underlying the tumor suppressive activity of this pathway are unknown. We developed a mouse model for colon cancer that identifies an early role for TGF-beta1 in tumor suppression and implicates TGF-beta2 or TGF-beta3 in the prevention of metastasis. Analysis of the development of colon cancer in TGF-beta1 knockout mice pinpoints the defect to the hyperplasty/adenoma transition and reveals that the mechanism involves an inability to maintain epithelial tissue organization and not a loss of growth control, increased inflammatory activity, or increased genetic instability. These mice provide a unique opportunity to investigate the specific role of TGF-beta1 at this critical transition in the development of colon cancer.