Should equine athletes commence training during skeletal development?: changes in tendon matrix associated with development, ageing, function and exercise

In human athletes, conditioning, training and competition are commenced before skeletal maturity. Yet in equine athletics, racing of young (age 2 years) horses remains contentious. Tendon injury persists as major causes of wastage in equine athletes. Minimising injury and associated welfare issues could involve a radical approach to the timing and implementation of conditioning and training. Tendons were examined from Thoroughbreds, Dutch Warmblood foals, working horses and also a group of wild horses to evaluate effects of age, function and exercise. Gross mechanical properties did not differ significantly with age or exercise, but showed a high variance within each group. Mechanical properties of tendon tissue showed significant differences as a function of age and location. The collagen fibril crimp angle and length showed a regional reduction in the central core with exercise and age, with a synergistic effect. Regional differences in collagen fibril diameter were seen in long-term exercised older horses, but not in short-term exercised, or younger, horses. The higher proportion of small fibrils in the central region of the long-term exercised horses did not correlate with new collagen formation and therefore appear to result from disassembly of the larger diameter fibrils. Fibril diameter distributions were influenced by exercise regimens in the growing foal. Changes in molecular composition occurred in longer-term exercise and older horses, in the centre of the tendon, with higher levels of type III collagen and changes in glycosaminoglycan (GAG) content. Cartilage Oligomeric Matrix Protein (COMP) levels also appear to be modulated by age, function and superimposition of exercise. These changes were all exacerbated with age and exercise, suggesting appropriate exercise in young horses may lead to a lower incidence of injury than in older horses. An hypothesis is advanced that immature tendon can respond to exercise while mature tendon has limited, if any, ability to do so. These findings support potentially controversial earlier conditioning and racing of younger, rather than older, equine athletes.

Monocyte adhesion and spreading on human endothelial cells is dependent on Rho-regulated receptor clustering

The GTPase Rho is known to mediate the assembly of integrin-containing focal adhesions and actin stress fibers. Here, we investigate the role of Rho in regulating the distribution of the monocyte-binding receptors E-selectin, ICAM-1, and VCAM-1 in human endothelial cells. Inhibition of Rho activity with C3 transferase or N19RhoA, a dominant negative RhoA mutant, reduced the adhesion of monocytes to activated endothelial cells and inhibited their spreading. Similar effects were observed after pretreatment of endothelial cells with cytochalasin D. In contrast, dominant negative Rac and Cdc42 proteins did not affect monocyte adhesion or spreading. C3 transferase and cytochalasin D did not alter the expression levels of monocyte-binding receptors on endothelial cells, but did inhibit clustering of E-selectin, ICAM-1, and VCAM-1 on the cell surface induced by monocyte adhesion or cross-linking antibodies. Similarly, N19RhoA inhibited receptor clustering. Monocyte adhesion and receptor cross-linking induced stress fiber assembly, and inhibitors of myosin light chain kinase prevented this response but did not affect receptor clustering. Finally, receptor clusters colocalized with ezrin/moesin/ radixin proteins. These results suggest that Rho is required in endothelial cells for the assembly of stable adhesions with monocytes via the clustering of monocyte-binding receptors and their association with the actin cytoskeleton, independent of stress fiber formation.

Epstein-Barr virus encodes a novel homolog of the bcl-2 oncogene that inhibits apoptosis and associates with Bax and Bak

The sequenced gammaherpesviruses each contain a single viral bcl-2 homolog (v-bcl-2) which may encode a protein that functions in preventing the apoptotic death of virus-infected cells. Epstein-Barr virus (EBV), a gammaherpesvirus associated with several lymphoid and epithelial malignancies, encodes the v-Bcl-2 homolog BHRF1. In this report the previously uncharacterized BALF1 open reading frame in EBV is identified as having significant sequence similarity to other v-bcl-2 homologs and cellular bcl-2. Transfection of cells with a BALF1 cDNA conferred apoptosis resistance. Furthermore, a recombinant green fluorescent protein-BALF1 fusion protein suppressed apoptosis and associated with Bax and Bak. These results indicate that EBV encodes a second functional v-bcl-2.

Physico-chemical analysis of Bordetella pertussis antigens

Physico-chemical methods are being developed for use in the control and standardization of acellular pertussis vaccines and their individual components. We have compared native and detoxified preparations of the B. pertussis antigens, pertussis toxin (PT), filamentous haemagglutinin (FHA), and the 69-kDa outer membrane protein (P69) using circular dichroism (CD), fluorescence spectroscopy, SDS-PAGE and FPLC gel filtration chromatography. Upon aldehyde detoxification, PT underwent a large change in its intrinsic fluorescence maximum (8-10 nm red-shift) and a large increase in its apparent size, detected by chromatography. Polyacrylamide gels showed individual subunits of the same apparent molecular weight (M(r)) as well as some polypeptides of higher M(r). FHA also changed conformation (5-nm red-shift in intrinsic fluorescence) upon aldehyde detoxification, with a resultant increase in the M(r)of its major constituent. The P69 protein appeared quite robust to formaldehyde treatment as measured by the same methods. Its near-UV CD spectrum contains a prominent tryptophan band; so this method may be more suitable for observing differences in conformation. We also examined an aluminium-desorbed DTaP preparation by these methods. When used in conjunction with immunochemical and toxicological assays, these methods are informative and useful in the characterization of candidate standards and should be valuable methods for ensuring the consistency of manufactured vaccines.

Evaluation of transmission electron microscopy for examination of components of acellular pertussis and combination vaccines

New acellular pertussis and combination vaccines vary in the concentration and presence or absence of specific components and in extent of adsorption to adjuvants. There is a pressing need to develop new control methods for acellular pertussis vaccines. Negative staining electron microscopy has been evaluated as a method for assessing the purity of individual vaccine components and the amount of adsorption to aluminium gels. Negative staining showed the characteristic morphology of vaccine components and permitted detection of contaminants and morphological changes. Reproducible results were obtained by use of a standardized negative staining technique and confidence in the technique was increased by comparison of previously unexamined specimens with a specimen that had been characterized by repeated observations. The degree of adsorption to aluminium adjuvants could only be assessed by observation of the amount of non-adsorbed material in the specimen. Negative staining electron microscopy can be used as one of a number of techniques for control of acellular pertussis combination vaccines.

An aerosol challenge model of Bordetella pertussis infection as a potential bioassay for acellular pertussis vaccines

Whole cell and five different types of acellular pertussis vaccine were assayed using a mouse aerosol challenge model which permitted delivery of a controlled, consistent dose of Bordetella pertussis to the lower respiratory tract. Using this system, the viable counts in the lungs of vaccinated mice were immunisation dose-dependent and allowed the protective capacity of different vaccine preparations to be distinguished. This model may thus provide the basis for a protection assay for pertussis vaccines. Comparison of acellular vaccines with a whole cell pertussis vaccine showed that the latter gave better active protection in mice but with a different dose-response relationship. Thus the two types of vaccine are not directly comparable in the same assay and require different reference standards. A pentavalent type acellular vaccine is suggested as a possible candidate standard for the acellular vaccine potency test. The results suggest that this aerosol challenge model has potential for use as a potency test for acellular pertussis vaccines.

Rape attitudes amongst British medical students

OBJECTIVES

To examine the rape attitudes of a sample of 252 British medical students.

DESIGN

A 20-item questionnaire was used.

SETTING

A London medical school.

SUBJECTS

Fourth-year medical students.

RESULTS

In general, students were well informed on legal and factual issues regarding rape and sexual assault. However, significant differences were found in the attitudes to rape between males and females. Female students were significantly more positive in their responses to victims.

CONCLUSIONS

These results support findings from previous studies of rape attitudes in other professional groups. Better knowledge and enlightened attitudes amongst health care staff can have a significant impact on the management of sexual assault and influence the likelihood of victims presenting for treatment. In conclusion, this study emphasizes the importance of teaching about sexual violence in British medical schools.

Trinucleotide (CAG) repeat length is positively correlated with the degree of DNA fragmentation in Huntington's disease striatum

Recent studies using DNA fragmentation assays suggest a role for apoptosis in cell death in Huntington's disease. In this study, we investigated the relationship between the degree of DNA fragmentation and the number of trinucleotide (CAG) repeats of the Huntington's disease gene in striatal tissue from Huntington's disease brains. We used frozen striatal tissue from 27 post mortem Huntington's disease brains (graded 0-4 on the Vonsattel classification, post mortem delay ranging from 4 to 41 h), plus control sections which were age, sex and post mortem delay matched from neurologically normal and Alzheimer's diseased striatal tissue. Our results show a significant positive correlation between the number of CAG repeats in the Huntington's disease gene and the degree of DNA fragmentation in Huntington's disease striatum. These results suggest that expanded CAG repeats in the Huntington's disease gene may lead to neuronal degeneration in Huntington's disease through an apoptotic mechanism.

Complement factor H or a related protein is a marker for transitional cell cancer of the bladder

The BTAstat and BTA TRAK tests are new immunoassays that detect and measure an antigen in the urine of individuals diagnosed with bladder cancer. As described in this report, the monoclonal antibodies used in these kits were developed by immunizing mice with partially purified protein preparations derived from the urine of patients with bladder cancer. The antigen that is recognized by the monoclonal antibodies was purified from the urine of bladder cancer patients by immunoaffinity chromatography and identified as being either complement factor H (FH) or a closely related protein (CFHrp) by partial amino acid sequence analysis. Like serum FH, the urine antigen was demonstrated to have a complement factor C3b binding site and to accelerate the degradation of C3b in the presence of complement factor I. The culture supernatants from several human bladder, cervical, and renal cancer cell lines contained antigen as determined by immunoassay, and antigen affinity-purified from HeLaS3 culture media was shown to have FH activity. Moreover, the cell lines were shown to make products of the expected sizes by reverse transcription-PCR using FH-specific primers. In contrast, normal human epithelial keratinocytes, a myeloid leukemia cell line, and the colon cancer line LS174T were negative for production of a FH-like protein (CFHrp). We propose that the expression of proteins with FH-like activities may confer a selective growth advantage to cancer cells in vivo by decreasing complement activity, thus aiding their escape from lysis by immune surveillance. Identification of these proteins as cancer products also suggests avenues of chemotherapy or immunotherapy of some cancers.

Multidimensional correlates of falls in older women

Older women who had fallen within the last year (n = 63) were compared with those who had not fallen (n = 67) on several psychological and motor measures. Both fallers and nonfallers demonstrated high levels of functioning. Discriminant analysis results indicated that a combination of variables, including physical activity and both psychological (general well-being, self-efficacy) and motor (functional reach, mobility) measures differentiated fallers and nonfallers. Results suggest that falling is a multidimensional phenomenon, that small declines on multiple factors may increase risk of falls, and that multifaceted interventions may help maintain high levels of functioning and prevent declines often associated with increased age.

Junctional adhesion molecule, a novel member of the immunoglobulin superfamily that distributes at intercellular junctions and modulates monocyte transmigration

Tight junctions are the most apical components of endothelial and epithelial intercellular cleft. In the endothelium these structures play an important role in the control of paracellular permeability to circulating cells and solutes. The only known integral membrane protein localized at sites of membrane-membrane interaction of tight junctions is occludin, which is linked inside the cells to a complex network of cytoskeletal and signaling proteins. We report here the identification of a novel protein (junctional adhesion molecule [JAM]) that is selectively concentrated at intercellular junctions of endothelial and epithelial cells of different origins. Confocal and immunoelectron microscopy shows that JAM codistributes with tight junction components at the apical region of the intercellular cleft. A cDNA clone encoding JAM defines a novel immunoglobulin gene superfamily member that consists of two V-type Ig domains. An mAb directed to JAM (BV11) was found to inhibit spontaneous and chemokine-induced monocyte transmigration through an endothelial cell monolayer in vitro. Systemic treatment of mice with BV11 mAb blocked monocyte infiltration upon chemokine administration in subcutaneous air pouches. Thus, JAM is a new component of endothelial and epithelial junctions that play a role in regulating monocyte transmigration.

"Os post peronei" and the posterolateral nutcracker impingement syndrome

Impingement syndromes have been described in relation to accessory or anomalous bony additions to the foot skeleton. We describe a hitherto undescribed accessory bone in the hindfoot causing posterolateral impingement in a 28-year-old woman.

Molecular genetics of spectral tuning in New World monkey color vision

Although most New World monkeys have only one X-linked photopigment locus, many species have three polymorphic alleles at the locus. The three alleles in the squirrel monkey and capuchin have spectral peaks near 562, 550, and 535 nm, respectively, and the three alleles in the marmoset and tamarin have spectral peaks near 562, 556, and 543 nm, respectively. To determine the amino acids responsible for the spectral sensitivity differences among these pigment variants, we sequenced all exons of the three alleles in each of these four species. From the deduced amino acid sequences and the spectral peak information and from previous studies of the spectral tuning of X-linked pigments in humans and New World monkeys, we estimated that the Ala --> Ser, Ile --> Phe, Gly --> Ser, Phe --> Tyr, and Ala --> Tyr substitutions at residue positions 180, 229, 233, 277, and 285, respectively, cause spectral shifts of about 5, -2, -1, 8, and 15 nm. On the other hand, the substitutions His --> Tyr, Met --> Val or Leu, and Ala --> Tyr at positions 116, 275, and 276, respectively, have no discernible spectral tuning effect, though residues 275 and 276 are inside the transmembrane domains. Many substitutions between Val and Ile or between Val and Ala have occurred in the transmembrane domains among the New World monkey pigment variants but apparently have no effect on spectral tuning. Our study suggests that, in addition to amino acid changes involving a hydroxyl group, large changes in residue size can also cause a spectral shift in a visual pigment.

Objective and subjective measures of the pharmacodynamic effects of Adderall in the treatment of children with ADHD in a controlled laboratory classroom setting

In a randomized double-blind crossover study of children with attention deficit hyperactivity disorder (ADHD), the time course effects of four doses of Adderall (5, 10, 15, and 20 mg) and an inactive (placebo) control, and an active (Ritalin) control were evaluated. A laboratory classroom setting was established in which subjective (teacher ratings of deportment and attention) and objective (scores on math tests) measurements were taken every 1.5 hours across the day. In addition to significant time and dose effects of Adderall, significant time-of-day effects were documented in the placebo condition for the subjective measure of deportment and objective measures of performance. Regression analyses were used to estimate the magnitude of these baseline effects. Correlations across time were used to evaluate the test-retest reliability of each measure in the face of these time-dependent placebo effects. After placebo/time adjustments, within-subject correlations between pairs of measures were used to evaluate the validity of the math test as a measure of response to stimulant medication.

Analog classroom assessment of Adderall in children with ADHD

OBJECTIVE

This was a randomized, double-blind, crossover study of 30 children with attention-deficit/hyperactivity disorder (ADHD) that evaluated the time course effects of four doses of Adderall (5, 10, 15, and 20 mg), an inactive control (placebo), and a positive control (clinical dose of methylphenidate).

METHOD

For each treatment condition, a capsule was administered in the morning and assessments were performed in an analog classroom setting every 1.5 hours across the day. Subjective (teacher ratings of deportment and attention) and objective (scores on math tests) measures were obtained for each classroom session, and these measures were used to evaluate time-response and dose response effects of Adderall.

RESULTS

For doses of Adderall greater than 5 mg, significant time course effects were observed. Rapid improvements on teacher ratings and math performance were observed by 1.5 hours after administration, and these effects dissipated by the end of the day. The specific pattern of time course effects depended on dose: the time of peak effects and the duration of action increased with dose of Adderall.

CONCLUSIONS

This documentation of efficacy in a controlled study supports the addition of Adderall to the armamentarium of psychotropic medications for the treatment of ADHD. The differences in time-response patterns of Adderall and methylphenidate may help tailor treatment to meet specific clinical needs of different children with ADHD.

Emergency vaccination of pigs against foot-and-mouth disease: protection against disease and reduction in contact transmission

The protective ability of two novel oil-based FMD vaccines in pigs was examined. Both vaccine formulations were shown to protect pigs against airborne challenge with homologous FMDV within four days of vaccination, but not at two and three days post-vaccination. Protection was associated with the induction of variable and low titre serum antibody responses. A transmission study showed that protective immunisation resulted in reduced virus excretion. Vaccination at seven days, but not at four days, prior to challenge prevented contact transmission of FMD. The two formulations tested in this study have the favourable characteristics of low viscosity, low reactivity and high potency emergency FMD vaccines for use in strategic vaccination campaigns to assist the control of outbreaks of FMD.

Contextual influences and goal perspectives among female youth sport participants

This study investigated two research questions: (1) do goal involvement and state anxiety vary between athletic games and athletic practices? and (2) do goal orientations change over the course of a competitive season as a function of the perceived team motivational climate? Middle school athletes (n = 127) were assessed on goal orientations, goal involvement, state anxiety, and motivational climate. Results indicated that athletes were more task involved and less anxious in practice than in game situations, and task goal orientation changed over the season relative to perceptions of mastery and performance climates. These results may indicate that sport offers an environment different from the academic setting and that mainstream psychology theories need to be adapted for the sport context.