22775136
The preparation, germination properties and stability of superdormant spores of Bacillus cereus.
AIMS
To determine yields, germination and stability of superdormant Bacillus cereus spores.


METHODS AND RESULTS
Superdormant B. cereus spores were isolated by germination with high concentrations of inosine or L-alanine in 2-5% yield and did not germinate with high concentrations of either of these germinants, but germinated like starting spores with Ca-DPA, dodecylamine, L-alanine plus inosine or concentrated complete medium. Yields of superdormant spores from germinations with low inosine concentrations were higher, and these spores germinated poorly with low inosine, but relatively normally with high inosine. Yields of superdormant spores were also higher when nonheat-activated spores were germinated. Superdormant spores stored at 4 degrees C slowly recovered some germination capacity, but recovery was slowed significantly at -20 degrees C and -80 degrees C.


CONCLUSIONS
Factors that influence levels of superdormant B. cereus spores and the properties of such spores are similar to those in B. megaterium and B. subtilis, suggesting there are common mechanisms involved in superdormancy of Bacillus spores.


SIGNIFICANCE
Superdormant spores are a major concern in the food industry, because the presence of such spores precludes decontamination strategies based on triggering spore germination followed by mild killing treatments. Studies of the properties of superdormant spores may suggest ways to eliminate them.
23924379
Superdormant spores of Bacillus species have elevated wet-heat resistance and temperature requirements for heat activation.
Purified superdormant spores of Bacillus cereus, B. megaterium, and B. subtilis isolated after optimal heat activation of dormant spores and subsequent germination with inosine, d-glucose, or l-valine, respectively, germinate very poorly with the original germinants used to remove dormant spores from spore populations, thus allowing isolation of the superdormant spores, and even with alternate germinants. However, these superdormant spores exhibited significant germination with the original or alternate germinants if the spores were heat activated at temperatures 8 to 15 degrees C higher than the optimal temperatures for the original dormant spores, although the levels of superdormant spore germination were not as great as those of dormant spores. Use of mixtures of original and alternate germinants lowered the heat activation temperature optima for both dormant and superdormant spores. The superdormant spores had higher wet-heat resistance and lower core water content than the original dormant spore populations, and the environment of dipicolinic acid in the core of superdormant spores as determined by Raman spectroscopy of individual spores differed from that in dormant spores. These results provide new information about the germination, heat activation optima, and wet-heat resistance of superdormant spores and the heterogeneity in these properties between individual members of dormant spore populations.
1212219
Effects of Mn levels on resistance of Bacillus megaterium spores to heat, radiation and hydrogen peroxide.
AIMS
To determine the effects of Mn levels in Bacillus megaterium sporulation and spores on spore resistance.


METHODS AND RESULTS
Bacillus megaterium was sporulated with no added MnCl(2) and up to 1 mmol l(-1) MnCl(2). The resultant spores were purified and loosely bound Mn removed, and spore Mn levels were found to vary c. 100-fold. The Mn level had no effect on spore γ-radiation resistance, but B. megaterium spores with elevated Mn levels had higher resistance to UVC radiation (as did Bacillus subtilis spores), wet and dry heat and H(2)O(2). However, levels of dipicolinic acid and the DNA-protective α/β-type small, acid-soluble spore proteins were the same in spores with high and low Mn levels.


CONCLUSIONS
Mn levels either in sporulation or in spores are important factors in determining levels of B. megaterium spore resistance to many agents, with the exception of γ-radiation.


SIGNIFICANCE AND IMPACT OF THE STUDY
The Mn level in sporulation is an important factor to consider when resistance properties of B. megaterium spores are examined, and will influence the UV resistance of B. subtilis spores, some of which are used as biological dosimeters.
25523214
Dissecting the correlation structure of a bivariate phenotype: Common genes or shared environment?
High correlations between two quantitative traits may be either due to common genetic factors or common environmental factors or a combination of both. In this study, we develop statistical methods to extract the genetic contribution to the total correlation between the components of a bivariate phenotype. Using data on bivariate phenotypes and marker genotypes for sib-pairs, we propose a test for linkage between a common QTL and a marker locus based on the conditional cross-sib trait correlations (trait 1 of sib 1—trait 2 of sib 2 and conversely) given the identity-by-descent (i.b.d.) sharing at the marker locus. We use Monte-Carlo simulations to evaluate the performance of the proposed test under different trait parameters and quantitative trait distributions. An application of the method is illustrated using data on two alcohol-related phenotypes from a project on the collaborative study on the genetics of alcoholism.
21178390
Natalizumab for active Crohn's disease.
BACKGROUND
In chronic inflammatory conditions such as Crohn's disease, the migration of leukocytes from the circulation into the parenchyma and their activation within inflammatory sites are mediated in part by alpha4 integrins.


METHODS
We conducted a double-blind, placebo-controlled trial of the alpha4 integrin-specific humanized monoclonal antibody natalizumab in 248 patients with moderate-to-severe Crohn's disease. Patients were randomly assigned to receive one of four treatments: two infusions of placebo; one infusion of 3 mg of natalizumab per kilogram of body weight, followed by placebo; two infusions of 3 mg of natalizumab per kilogram; or two infusions of 6 mg of natalizumab per kilogram. Infusions were given four weeks apart. Outcomes included changes in scores for the Crohn's Disease Activity Index (higher scores indicate more severe disease), the health-related quality of life, and C-reactive protein levels.


RESULTS
The group given two infusions of 6 mg of natalizumab per kilogram did not have a significantly higher rate of clinical remission (defined by a score of less than 150 on the Crohn's Disease Activity Index) than the placebo group at week 6 (the prospectively defined primary end point in the efficacy analysis). However, both groups that received two infusions of natalizumab had higher remission rates than the placebo group at multiple time points. Natalizumab also produced a significant improvement in response rates (defined by a reduction of at least 70 points in the score on the Crohn's Disease Activity Index). The highest remission rate was 44 percent and the highest response rate was 71 percent (at week 6 in the group given two infusions of 3 mg per kilogram). Overall, the two infusions of 6 mg of natalizumab per kilogram and of 3 mg per kilogram had similar effects. The quality of life improved in all natalizumab groups; C-reactive protein levels improved in groups receiving two infusions of natalizumab. The rates of adverse events were similar in all four groups.


CONCLUSIONS
Treatment with the selective adhesion-molecule inhibitor natalizumab increased the rates of clinical remission and response, improved the quality of life and C-reactive protein levels, and was well tolerated in patients with active Crohn's disease.
11373784
Fatal Outcome Despite Full Lympho-Hematopoietic Reconstitution After Allogeneic Stem Cell Transplantation in Atypical Ataxia Telangiectasia
Allogeneic hematopoietic stem cell transplantation (HSCT) has not been a therapeutic option in ataxia telangiectasia (AT) due to overwhelming toxicity of conditioning in the context of the global DNA repair deficiency. Furthermore HSCT is unable to cure neurological involvement of AT. We report on a Turkish child with a Hyper IgM phenotype disorder, in which clinical aspects of AT were absent and thus, AT not diagnosed. He was transplanted with a reduced toxicity, but full intensity conditioning regimen comprising treosulfan, fludarabine and ATG. The peritransplant period was uneventful and the patient was discharged at day +57. 8 months after HSCT, the patient developed hepatopathy with monoclonal gammopathy of unclear significance and died due to hepatic failure and encephalopathy at the age of 32 months. Post mortem high throughput sequencing revealed a mutation in the ATM gene.
23757890
Both avian and mammalian embryonic myoblasts are intrinsically heterogeneous
Adult skeletal muscles are composed of different fibre types. What initiates the distinctive muscle fibre type-specific specialization in a developing embryo is still controversial. In vitro studies of avian muscles have shown the expression of one of the slow myosin heavy chains, SM2, in only some myotubes. In this report we demonstrate the expression of another slow myosin heavy chain, SM1, restricted to only some chicken myotubes (presumptive slow) in vitro. We also demonstrate that as is the case for avian species, distinct fast and slow myogenic cells are detectable in mammalian species, human and rat, during in vitro development in the absence of innervation. While antibodies to fast myosin heavy chains stained all myotubes dark in these muscle cell cultures, antibodies to slow myosin heavy chains stained only a proportion of the myotubes (presumptive slow). The other myotubes were either unstained or only weakly stained with slow myosin heavy c hain antibodies. The muscle cell cultures prepared from different developmental stages of rat skeletal muscles showed a reduction in the number of slow myosin heavy chain-positive myotubes with advancing foetal growth. It is concluded that embryonic myogenic cells that are likely to form distinct fast or slow muscle fibre types are intrinsically heterogeneous, not only in avian but also in mammalian species, although extrinsic factors reinforce and modify such commitment throughout subsequent development. © Kluwer Academic Publishers.
12424757
Endotoxin-induced organ injury.
OBJECTIVE
To review the effects of endotoxemia on the major organ systems of the body and discuss potential mechanisms of tissue injury.


DESIGN
Appraisal of 60 articles representing a cross section of studies relating to in vivo and in vitro responses to endotoxin.


MAIN METHODS
Cell cultures, isolated tissue preparations, animal and human studies.


RESULTS
Endotoxemia results in the activation of numerous cellular and hematogenous mediators. These mediators range from prostaglandins, thromboxanes, and leukotrienes, to complement components. Tumor necrosis factor may be responsible for initiating many of the observed responses to endotoxin. Species and tissue specificity are a prominent feature of the response to endotoxin.


CONCLUSIONS
No single agent can yet be implicated as the common mediator of endotoxin-induced organ injury. Endotoxin initiates the elaboration of a cascade of secondary mediators that amplify the response to the initial insult. The relative importance of individual agents as mediators of the response to endotoxin varies with the experimental model studied.