Changes in human muscle transverse relaxation following short-term creatine supplementation

The rapid increase in body mass that often occurs following creatine (Cr) supplementation is believed to be due to intracellular water retention. The purpose of this study was to determine whether Cr consumption alters the magnetic resonance (MR) transverse relaxation (T(2)) distribution of skeletal muscle. Transverse relaxation can be used to model water compartments within a cell or tissue. In this double-blind study, subjects were asked to supplement their normal diet with creatine monohydrate (20 g day(-1) for 5 days) mixed with a grape drink (Creatine group, n = 7), or the grape drink alone (Placebo group, n = 8). Phosphorous MR spectroscopy was used to determine the effectiveness of the supplementation protocol. Subjects that responded to the Cr supplementation (i.e. showed a > 5 % increase in the ratio of the levels of phosphocreatine (PCr) and ATP) were placed in the Creatine group. Both proton MR imaging and spectroscopy were used to acquire T(2) data, at 1.89 T, from the flexor digitorum profundus muscle of each subject before and after supplementation. Following the supplementation period, the Creatine group showed a gain in body mass (1.2 +/- 0.8 kg, P < 0.05, mean +/- S.D.), and an increase in PCr/ATP ratio (23.8 +/- 16.4 %, P < 0.001). Neither group showed any changes in intracellular pH or T(2) calculated from MR images. However, the spectroscopy data revealed at least three components (> 5 ms) at approximately 20, 40 and 125 ms in both groups. Only in the Creatine group was there an increase in the apparent proton concentration of the two shorter components combined (+5.0 +/- 4.7 %, P < 0.05). According to the cellular water compartment model, the changes observed in the shorter T(2) components are consistent with an increase in intracellular water.     

Cloning and expression of the major secreted cathepsin B-like protein from juvenile Fasciola hepatica and analysis of immunogenicity following liver fluke infection

The functions of the cathepsin B-like proteases in liver flukes are unknown and analysis has been hindered by a lack of protein for study, since the protein is produced in small amounts by juvenile flukes. To circumvent this, we isolated and characterized a cDNA encoding the major secreted cathepsin B from Fasciola hepatica. The predicted preproprotein is 339 amino acids in length, with the mature protease predicted to be 254 amino acids long, and shows significant similarity to parasite and mammalian cathepsin B. Only one of the two conserved histidine residues required for cathepsin B exopeptidase activity is predicted to be present. Recombinant preproprotein was produced in yeast, and it was shown that the recombinant proprotein can undergo a degree of self-processing in vitro to the mature form, which is active against gelatin and synthetic peptide substrates. The recombinant protein is antigenic in vaccinated rats, and antibodies to the protein are detected early after infection of rats and sheep with F. hepatica. The kinetics of the response to cathepsin B and cathepsin L after infection of sheep and rats confirm the temporal expression of these proteins during the life cycle of the parasite.     

Detection and Identification of Actinobacillus pleuropneumoniae Serotype 5 by Multiplex PCR

Serotyping of Actinobacillus pleuropneumoniae is based on detection of the serotype-specific capsular antigen. However, not all isolates can be serotyped, and some may cross-react with multiple serotyping reagents. To improve sensitivity and specificity of serotyping and for early detection, a multiplex PCR assay was developed for detection of A. pleuropneumoniae and identification of serotype 5 isolates. DNA sequences specific to the conserved export and serotype-specific biosynthesis regions of the capsular polysaccharide of A. pleuropneumoniae serotype 5 were used as primers to amplify 0.7- and 1.1-kb DNA fragments, respectively. The 0.7-kb fragment was amplified from all strains of A. pleuropneumoniae tested with the exception of serotype 4. The 0.7-kb fragment was not amplified from any heterologous species that are also common pathogens or commensals of swine. In contrast, the 1.1-kb fragment was amplified from all serotype 5 strains only. The assay was capable of amplifying DNA from less than 10² CFU. The A. pleuropneumoniae serotype 5 capsular DNA products were readily amplified from lung tissues obtained from infected swine, although the 1.1-kb product was not amplified from some tissues stored frozen for 6 years. The multiplex PCR assay enabled us to detect A. pleuropneumoniae rapidly and to distinguish serotype 5 strains from other serotypes. The use of primers specific to the biosynthesis regions of other A. pleuropneumoniae serotypes would expand the diagnostic and epidemiologic capabilities of this assay.     

Inhibition of interleukin-17 prevents the development of arthritis in vaccinated mice challenged with Borrelia burgdorferi

We showed that Borrelia burgdorferi-vaccinated interferon gamma-deficient (IFN-gamma(0)) mice challenged with the Lyme spirochete developed a prominent chronic severe destructive osteoarthropathy. The immune response underlying the development of the severe destructive arthritis involves interleukin-17 (IL-17). Treatment of vaccinated IFN-gamma(0) mice challenged with B. burgdorferi with anti-IL-17 antibody delayed the onset of swelling of the hind paws but, more importantly, inhibited the development of arthritis. Histopathologic examination confirmed that treatment with anti-IL-17 antibody prevented the destructive arthropathy seen in vaccinated and challenged IFN-gamma(0) mice. Similar preventive results were obtained when vaccinated and challenged IFN-gamma(0) mice were treated with anti-IL-17 receptor antibody or sequentially with anti-IL-17 antibody followed by anti-IL-17 receptor antibody. By contrast, treatment of vaccinated and challenged IFN-gamma(0) mice with recombinant IL-17 (rIL-17) did not alter the development and progression of arthritis found in vaccinated and challenged IFN-gamma(0) mice without treatment with rIL-17. Therapeutic intervention may be a realistic approach to prevent arthritis, especially if IL-17 is involved in the perpetuation of chronic or intermittent arthritis.     

An observational study of variation in GPs' out-of-hours emergency referrals.

Out-of-hours organisations are responsible for the care of patients 70% of the time, and their GPs act as gatekeepers to secondary care services. This observational study identifies the variations in GPs' out-of-hours referral rates to secondary care and factors that could explain these variations. One hundred and forty-nine GPs who worked in one UK general practice out-of-hours cooperative which served 19 practices with 167 000 registered patients. Data on patients who accessed the out-of-hours service over 3 years (2001-2004) were examined. Factors thought to be predictors of variation in referral rates were investigated using logistic regression analysis. There was a fivefold difference in referral rates between the lowest and highest referring quartiles of GPs (OR [odds ratio] = 4.56, CI [confidence interval] = 3.86 to 5.38). The sex (female) of the clinician, the time of the consultation (11 pm to 7 am), and the place of the consultation (home visit) accounted for some, but not all, of the increased referral rates. A doctor working out-of-hours disproportionately influences the fate of the patient, the number of hospital admissions, and extra costs to the health service. There is a need for follow-up studies to investigate the factors associated with referral behaviour, and how the variation relates to patient factors and the resources available. These findings could be used when planning the staffing of out-of-hours services to optimise appropriate care and minimise patients' exposure to unnecessary intrusive and expensive hospital care.     

Neurobehavioral Symptoms and Family Functioning in Traumatically Brain-Injured Adults

Traumatic brain injury (TBI) often results in a myriad of symptoms across physical, cognitive, and neurobehavioral domains. Despite inherent limitations associated with physical or cognitive impairments, the extant literature suggests that neurobehavioral symptoms tend to be the most distressing symptoms for the family and are more strongly related to poor outcome for the patient. The Neuropsychology Behavior and Affect Profile (NBAP) along with the General Functioning subscale of the Family Assessment Device (FAD-GF) and the Perceived Stress Scale were administered to 153 family members of persons who had sustained a TBI. The results provide new normative data and statistical support for the NBAP as a promising measure of neurobehavioral symptomatology following TBI. The correlation of.54 (p <.01) between FAD-GF and Full Scale NBAP scores provides powerful support for the hypothesis that family dysfunction is related to the presence of neurobehavioral symptoms in the patient. NBAP domains of Depression, Inappropriateness, Pragnosia, and Indifference appear most strongly related to family functioning and also bear a significant relationship to caregiver stress level and patient unemployment, whereas injury severity had little impact on either family functioning or neurobehavioral symptoms. The findings reinforce the significance of neurobehavioral symptoms and fortify their proposed link to family dysfunction post-TBI.     

Reproducibility of interpretation of the test for antibody-coated bacteria in urinary sediment.

The direct immunofluorescence technique for detecting antibody-coated bacteria in urinary sediment is felt to be useful in distinguishing infection of the kidney from infection of the bladder. An independent, blind multiple-reading system was used to measure interobserver variability in the evaluation of slides of urinary sediments for antibody-coated bacteria. Three independent observers agreed unanimously on first reading in 88% of 253 specimens. When compared with the majority opinion, the sensitivity and specificity of an individual reading were 91 and 95%, respectively.     

Mast cell heterogeneity: Evidence and implications

Mast cells and basophils play a fundamental role in the pathogenesis of allergic disease, although their physiologic role is largely unknown. A large body of evidence now indicates that the properties of mast cells are dependent on the tissue and species from which they are derived. Such mast cell heterogeneity encompasses differences in morphology, development, cytochemistry, and function. The evidence for such heterogeneity, and some of its clinical implications, is discussed.     

Surface antigens on Schistosoma mansoni. II. Adsorption of a Forssman-like host antigen by schistosomula

A study was made of the nature of mouse (host) antigens adsorbed by schistosomula of Schistosoma mansoni. Using the mixed antiglobulin test, extracts of a number of individual mouse tissues were tested for their ability to coat schistosomula. All were effective to some extent, with the greatest activity being found in extracts of the lung and spleen. Antibodies against the schistosomulum-coating antigen as well as surface host antigens of adult Schistosoma mansoni were removed by absorbing with erythrocytes from a number of Forssman-positive but not Forssman-negative animal species. These antibodies were also absorbed by Forssman-positive guineapig kidney extract and methanol soluble (Forssman-positive) but not insoluble fractions of sheep erythrocyte stromata and mouse lungs. Schistosomula could be coated in vitro with methanol soluble fractions of mouse lung and erythrocytes and sheep erythrocytes. Though both mouse and sheep coating antigens reacted with anti-mouse and anti-sheep antibodies, reactions were stronger with the homologous antiserum. It was concluded that schistosomula of Schistosoma mansoni adsorb from mice an antigen similar but not identical to the Forssman antigen of sheep erythrocytes, and that this antigen is also found on the surface of adult worms.