The Biochemical Literacy Framework: Inviting pedagogical innovation in higher education

When developing meaningful curricula, institutions must engage with the desired disciplinary attributes of their graduates. Successfully employed in several areas, including psychology and chemistry, disciplinary literacies provide structure for the development of core competencies-pursuing progressive education. To this end, we have sought to develop a comprehensive blueprint of a graduate biochemist, providing detailed insight into the development of skills in the context of disciplinary knowledge. The Biochemical Literacy Framework (BCLF) aspires to encourage innovative course design in both the biochemical field and beyond through stimulating discussion among individuals developing undergraduate biochemistry degree courses based on pedagogical best practice. Here, we examine the concept of biochemical literacy aiming to start answering the question: What must individuals do and know to approach and transform ideas in the context of the biochemical sciences? The BCLF began with the guidance published by relevant learned societies - including the Royal Society of Biology, the Biochemical Society, the American Society for Biochemistry and Molecular Biology and the Quality Assurance Agency, before considering relevant pedagogical literature. We propose that biochemical literacy is comprised of seven key skills: critical thinking, self-management, communication, information literacy, visual literacy, practical skills and content knowledge. Together, these form a dynamic, highly interconnected and interrelated meta-literacy supporting the use of evidence-based, robust learning techniques. The BCLF is intended to form the foundation for discussion between colleagues, in addition to forming the groundwork for both pragmatic and exploratory future studies into facilitating and further defining biochemical literacy.

Validation of masks for determination of V̇O2 max in horses exercising at high intensity

BACKGROUND

The need for a horse to be ridden while wearing a measurement device that allows unrestricted ventilation and gas exchange has hampered accurate measurement of its maximal oxygen consumption (V̇O₂ max) under field conditions.

OBJECTIVES

Design and validate a facemask with the potential to measure V̇O₂ max accurately in the field.

STUDY DESIGN

Experiment with 6 × 6 Latin square design.

METHODS

Two variations of a mask and associated electronic control module (ECM) were designed to enable breath-by-breath measurement of airflows through two 7.8 cm diameter pneumotachometers located 7.5 cm in front of each narus. The ECM was comprised of an analogue-to-digital converter and a lithium-ion battery that provided power and signal filtering to the pneumotachometers and an oxygen sensing cell, and powered a pump connected to gas sampling ports between the nares and pneumotachometers. Airflow and oxygen content of inspired and expired gases were recorded through the ECM and electronically transferred to a notebook. V̇O₂ was determined from these recordings using a customised software program. Mask B encased the lower jaw. Mask R left the jaw free so the horse could wear a bit if ridden. V̇O₂ max and arterial blood gases were measured in 6 horses during multiple treadmill tests. Each mask was worn twice and results compared to those from an established open flow-through system (O) by ANOVA-RM (P<0.05). System utility was evaluated using the intraclass correlation coefficient of 4 independent raters.

RESULTS

Blood gases and V̇O₂ max (151.9±7.0 [mean±s.d.; O], 151.5±9.6 [B], 149.5±7.5 [R] ml/[kg.min]) were not different between masks. V̇O₂ max measures were reproducible for each mask. Intraclass correlation coefficient between raters = 0.99.

MAIN LIMITATIONS

Some rebreathing of expired air from mask dead space.

CONCLUSION

Masks capable of measuring V̇O₂ max during treadmill exercise were developed, tested and found to be accurate. Mask R has potential application to measurement of V̇O₂ max under field conditions.

Reliability of breath by breath spirometry and relative flow-time indices for pulmonary function testing in horses

Background

Respiratory problems are common in horses, and are often diagnosed as a cause of poor athletic performance. Reliable, accurate and sensitive spirometric tests of airway function in resting horses would assist with the diagnosis of limitations to breathing and facilitate investigations of the effects of various treatments on breathing capacity. The evaluation of respiratory function in horses is challenging and suitable procedures are not widely available to equine practitioners. The determination of relative flow or flow-time measures is used in paediatric patients where compliance may limit conventional pulmonary function techniques. The aim of the current study was to characterise absolute and relative indices of respiratory function in healthy horses during eupnoea (tidal breathing) and carbon dioxide (CO₂)-induced hyperpnoea (rebreathing) using a modified mask pneumotrachographic technique well suited to equine practice, and to evaluate the reliability of this technique over three consecutive days. Coefficients of variation, intra-class correlations, mean differences and 95% confidence intervals across all days of testing were established for each parameter.

Results

The technique provided absolute measures of respiratory function (respiratory rate, tidal volume, peak inspiratory and expiratory flows, time to peak flow) consistent with previous studies and there was no significant effect of day on any measure of respiratory function. Variability of measurements was decreased during hyperpnea caused by rebreathing CO₂, but a number of relative flow-time variables demonstrated good agreement during eupnoeic respiration.

Conclusions

The technique was well tolerated by horses and study findings suggest the technique is suitable for evaluation of respiratory function in horses. The use of relative flow-time variables provided reproducible (consistent) results, suggesting the technique may be of use for repeated measures studies in horses during tidal breathing or rebreathing.

Electronic supplementary material

The online version of this article (doi:10.1186/s12917-016-0893-3) contains supplementary material, which is available to authorized users.

The effect of prone positioning with surgical bolsters on liver blood flow in healthy volunteers

This study sought to identify changes in hepatic flood flow and cardiac output during prone positioning on surgical bolsters in awake volunteers, and was prompted by a local incident of significant hepatic dysfunction following surgery in the prone position. Cardiac output was determined using the non-invasive Peñáz technique, and plasma disappearance rate of indocyanine green (ICG-PDR) was measured as a surrogate maker for hepatic blood flow along with serum hepatic enzyme assays. Measurements were made after one hour in supine, prone and returned supine positions. Ten volunteers completed the study. There were significant changes in the disappearance rate of indocyanine green, which decreased this from mean (SD) 31.1 (9.70) supine to 19.6 (4.37)%.min prone, respectively (p = 0.02), increasing on return to the supine position to 24.6 (5.54)%.min (p = 0.019). Cardiac output was also significantly reduced when changing from the supine to the prone position, from mean (SD) 4.7 (1.0 to 3.5 (1.1) (l.min(-1) ), respectively (p = 0.002). We demonstrated an acute and reversible change in both hepatocellular function and cardiac output associated with the prone position.

Number, causes and destinations of horses leaving the Australian Thoroughbred and Standardbred racing industries

OBJECTIVE

Significant proportions of horses leave the Australian Thoroughbred and Standardbred racing industries, which has ramifications for both the economic sustainability and the public perception of racing. The aim of this study was to quantify potential horse wastage, describe the destinations of exiting horses and identify risk factors for horses going to these destinations.

METHODS

Questionnaires were sent to 1258 selected Thoroughbred and 981 Standardbred trainers, with response rates of 30% and 32%, respectively. The survey investigated the role of various risk factors for wastage, including horse age, sex and number of years in training. The destination of departing horses was also examined in relation to these risk factors.

RESULTS

Total horse exit rates for the 2002-03 official race year were 39.7% and 38.7% for the Thoroughbred and Standardbred racing industries, respectively. Reasons for leaving included 'poor performance/slow' (36.5% Thoroughbreds, 35.2% Standardbreds), 'illness/injury' (31.0%, 27.1%), 'to breed' (9.4%, 10.1%), 'unsuitable temperament/behaviour' (6.4%, 6.4%) and 'other' (16.8%, 21.2%). Statistically significant (P < 0.001) risk factors influencing the destinations of both Thoroughbred and Standardbred racing horses included whether the trainer owned the horses, sex, age and reasons for leaving. In addition, some factors were specific to one breed or the other.

CONCLUSIONS

Improved behaviour training and early identification of the causes of poor performance could assist in reducing wastage.

Pulmonary function measurements immediately after exercise are correlated with neutrophil percentage in tracheal aspirates in horses with poor racing performance

Inflammatory airway disease (IAD) is common in racehorses, and is a cause of wastage in the industry. IAD has been diagnosed by measurement of percent neutrophils (N%) in tracheal aspirates (TA). The aim of this study was to investigate whether spirometric indices of pulmonary function were correlated with N% in TAs. Limits to breathing were measured by analyses of relationships between relative times and relative respiratory gas flows during inspiration and expiration in individual breaths recorded after exercise. Horses with higher N% had significantly lower relative gas flows at the same relative times during inspiration and expiration, suggesting a limit to breathing. These findings confirm a physiological basis for the measurement of N% in TA after exercise for diagnosis of IAD. Spirometric pulmonary function testing using analyses of individual breaths after exercise has application for assessment of pulmonary function and poor exercise performance.

Shuttle imaging radar experiment

The shuttle imaging radar (SIR-A) acquired images of a variety of the earth's geologic areas covering about 10 million square kilometers. Structural and geomorphic features such as faults, folds, outcrops, and dunes are clearly visible in both tropical and arid regions. The combination of SIR-A and Seasat images provides additional information about the surface physical properties: topography and roughness. Ocean features were also observed, including large internal waves in the Andaman Sea.

Correlation of race earnings with velocity at maximal heart rate during a field exercise test in Thoroughbred racehorses

REASONS FOR PERFORMING STUDY

Running ability of Thoroughbred racehorses is correlated with maximal oxygen uptake, and the velocity at maximal oxygen uptake is highly correlated with the velocity at maximal heart rate (VHRmax).

OBJECTIVE

To investigate the relationship between VHRmax and racing performance, expressed as 'peak dollars earned per race start'.

METHODS

Heart rate (HR) and velocity were recorded in 25 Thoroughbred racehorses during trotting and subsequent fast gallops in the field at velocities of 15-16 m/sec. Velocity was recorded by a global positioning system (GPS). Maximal HR (HRmax) and maximal velocity (Vmax) were identified, and a linear regression of HR on velocity for trotting and galloping data was constructed to derive VHRmax. Horses followed the training programme designed by one trainer, had at least 6 race starts and were clinically sound at the time of testing. Race earnings were expressed as the peak dollars per start in the horse's race career. Data were normalised using the results for the square root of 'peak dollars earned per race start' and the significance of associations between variables was determined by correlation coefficient and least square analyses.

RESULTS

Horses with higher VHRmax earned significantly more dollars per race start (r = 0.41, P<0.05), and horses with VHRmax less than 14.5 m/sec had mean earnings of less than A$2500 per race. There were no correlations between race earnings and either HRmax or Vmax.

CONCLUSION

Field studies of the relationship between HR and velocity with a GPS enable identification of horses with limited earnings.

POTENTIAL RELEVANCE

This study demonstrates that a field test of fitness of Thoroughbred racehorses that correlates with retrospective racing ability is feasible. The technique has potential application in commercial training environments assisting with decisions concerning racing careers of individual racehorses.

Effect of corticosteroid and bronchodilator therapy on bronchoalveolar lavage cytology following intrapulmonary blood inoculation

REASON FOR PERFORMING STUDY

Intrapulmonary blood causes an inflammatory response. Modifying this inflammatory response may be useful in the treatment of exercise induced pulmonary haemorrhage (EIPH).

OBJECTIVES

To evaluate the efficacy of 3 treatments, an oral bronchodilator, inhaled steroid and oral steroid in modifying the cellular response to intrapulmonary blood inoculation.

MATERIALS AND METHODS

Experimental design was a randomised block divided into 4 experimental segments of 2 weeks. Eight normal horses were randomly assigned to pairs and treatments. Autologous blood was inoculated into the lungs on 4 occasions over an 8 week period. For each treatment, a bronchoalveolar lavage (BAL) sample was collected on Day 0 and then 2 randomly selected segmental bronchi (one in each lung) were inoculated with blood (50 ml). BAL fluid was collected from one inoculated bronchus on Day 3 and from the other on Day 10. From BAL samples, total RBC and total and differential WBC were determined. Results for percentages and absolute cell counts were expressed as mean +/- s.e. and analysed using one, 2 and 3 way analysis of variance.

RESULTS

All treatments significantly reduced the number of erythrophages at Day 3 (P = 0.02) Treatment with oral prednisolone resulted in a significantly higher percentage of macrophages (P = 0.03) and also reduced the relative and absolute number of haemosiderophages in BAL compared to the other 2 treatments at Day 10 (P = 0.07).

CONCLUSION

We concluded that treatments altered the dynamics of cell populations in BAL following blood inoculation. Whether this alters the evolution of lung lesions following episodes of EIPH and indeed whether there are benefits for equine lungs following episodes of EIPH, remain to be determined.

POTENTIAL RELEVANCE

Future studies into treatments for EIPH may benefit from incorporating a variety of dose rates for oral prednisolone and a longer period of evaluation. Such studies may also benefit from the use of cell activation markers. The concomitant use of pulmonary function testing and cytology in the field may assist in ascertaining whether treatments influence the performance and welfare of athletic horses subsequent to episodes of EIPH.

Observations on respiratory flow strategies during and after intense treadmill exercise to fatigue in Thoroughbred racehorses

REASONS FOR PERFORMING STUDY

Locomotor-respiratory coupled (LRC) breath types are a feature of galloping exercise in horses. Differences in breath type have been demonstrated during exercise in particular the 'big respiratory cycle' (BRC) and 'flow hesitation'. To investigate breath types during recovery and quantitatively investigate BRCs during exercise to understanding the mechanism driving BRCs.

OBJECTIVES

To investigate the occurrence of different breath types during and after intense treadmill exercise, and test the hypothesis that large breaths (BRCs) were a function of respiratory frequency.

METHODS

Six trained and clinically normal Thoroughbred horses were exercise tested on a treadmill (slope 10%). Breath-by-breath pulmonary ventilation was measured continuously during exercise and recovery using a Quadflow mask.

RESULTS

Five different breath types were identified, and classified as normal monophasic, normal biphasic, deglutition, effort pause, or large breaths. Exercising at 10 m/sec, the number of large breaths was significantly related to Rf (r = -0.86, P = 0.03). During 120 sec after exercise there were 2 distinct populations of breaths, large and normal monophasic.

CONCLUSIONS

BRC type breaths are a normal feature of ventilation during and after intense exercise. In recovery there are two distinct breath populations. During exercise BRC frequency is inversely associated with respiratory frequency and highly dependant on the individual horse. From intense exercise to recovery, high flow rates and LRC limited tidal volumes are replaced by high tidal volumes and progressively decreasing flow rates. There is a temporal association between BRC occurrence and PECO2.

POTENTIAL RELEVANCE

Breath types and the physiological mechanism for driving each type is important in the clinical interpretation of respiratory disease or dysfunction. The demonstration of BRC association with PECO2 may help understand the driving mechanism for the BRC. In pulmonary function testing, breath type is important in quantitative results. The demonstration that high tidal flows with limited tidal volumes during intense exercise being replaced by high tidal volumes and progressively decreasing flows in recovery has potential clinical relevance.

Measurements of fitness in Thoroughbred racehorses using field studies of heart rate and velocity with a global positioning system

REASONS FOR PERFORMING STUDY

Field based studies of changes in fitness are difficult to conduct in galloping Thoroughbreds. Measurements of heart rate (HR) and real time velocity with a global positioning system (GPS) could provide a method for routine field studies of fitness.

OBJECTIVE

To investigate measurements of fitness in the field without using multiple, standardised steps of increasing velocity in the exercise test.

METHODS

Twelve healthy 3- to 5-year-old Thoroughbreds were used in the study of reliability, and twelve 2-year-old Thoroughbreds in the investigation of the effect of training. Five second averages of velocity and HR were recorded during a typical fast exercise training session, using a GPS and Polar HR monitor. A standardised exercise test protocol was not used. Regression analyses using trot and gallop data were used to calculate velocities at HR of 200 beats/min (V200), and at maximal HR (VHRmax). Data were collected on consecutive 'fast' day training sessions to assess the reliability of measurements. The effect of training was investigated with fitness tests in weeks 2 and 6 of 'fast' training. Absolute and relative differences were calculated to evaluate reliability, and paired t tests were used to detect an effect of training.

RESULTS

VHRmax, V200 and HRmax were reliable measurements of fitness, with mean differences of 2% or less. Reliability of VHRmax was not dependent on VHRmax. VHRmax and V200 both increased significantly with training (P<0.01), but there was no effect of training on HRmax. There were no significant changes in the slope or intercept of the regression equations after training.

CONCLUSIONS

Velocity and HR measurements during field gallop exercise provided reliable measures of fitness which enabled a measurement of the response to training.

POTENTIAL RELEVANCE

This approach offers a simple, noninvasive method for monitoring adaptations to training in the field.

Postprandial arterial vasodilation in the equine distal thoracic limb

The effects of feeding on blood flow to the equine foot are poorly understood. In a temperature-controlled room, duplex Doppler ultrasonographic observations were made pre- and postprandially of the lateral proper palmar digital artery of 5 horses, randomly assigned to twice and 4 times daily feeding in an unbalanced 2 period crossover design. Arterial diameter and blood velocity were measured over 4 h and additional observations made of heart rate, blood pressure, total plasma protein, packed cell volume, plasma glucose and insulin. There was no effect of the feeding regimen on any variable. Postprandially, there were significant increases in arterial diameter, blood velocity, total plasma protein, plasma glucose and insulin; the other variables were unchanged. It appeared that the normal postprandial response was an increase in blood flow to the foot. The value of ultrasonography for noninvasive investigation of the peripheral vasculature of the conscious horse was established; and in the future it may have a role in the diagnosis of vascular diseases of the foot.

Incidence rate of musculoskeletal injuries and determinants of time to recovery in young Australian Thoroughbred racehorses

OBJECTIVE

To describe the incidence rate of musculoskeletal (MS) injuries and investigate the factors that influence recovery from MS injury in young Thoroughbred horses in Australia.

METHODS

Training and injury data were collected at fortnightly intervals from 14 trainers in New South Wales. Incidence rates were calculated for initial injuries stratified by age-class and sex. Survival analysis methods were used to investigate the time to recovery after the first MS injury (measured as a start in a race or barrier trial).

RESULTS

For the 248 racehorses enrolled, there were 428 injuries recorded; 2-year-olds were 2.99-fold more likely than 3-year-olds to sustain an MS injury. The cumulative percentage of horses that had recovered within 6 months was 55%. The time to recovery was longest in horses whose fast gallop speed prior to injury was < 890 m/min.

CONCLUSION

This study supports the finding that shin soreness is the most common MS injury in young Australian Thoroughbreds. There was an increased rate of MS injury in 2-year-olds compared with 3-year-olds. However, it was impossible to determine if the increased risk in 2-year-olds was related to age, the start of training or a combination of both. The study also found that horses performing at higher exercise speeds prior to injury were more likely to recover. There was a significant effect of trainer, suggesting that other factors related to trainer may influence the time to the recovery. Additional research is required to understand the determinants of time to recovery.

Physiology of equine performance and associated tests of function

This review addresses the physiology of performance horses in the context of functional tests aimed at assisting clinicians in the search for explanations of the individual's limitations, actual or perceived as below expectation. The intention is to assist clinicians who are faced frequently by owners or trainers seeking explanations for poor performance; and for research workers as a basis on which to proceed in their search for new methodologies, particularly those that can be applied in the field as for treadmill exercise. The review sets out fundamental physiological pathways, the entailment of which may represent a limiting factor to performance, while taking into account the individual's status, including anamnesis and the possibility of actual disease being present. Tests that assess the possible roles of several body systems, as causes of limited performance, are discussed. These systems include pulmonary, cardiovascular and neuromuscular systems. The evaluation of anaerobic and aerobic energy pathways is also discussed. Emphasis is given to the assessment of pulmonary ventilation by techniques such as spirometry and ergospirometry. These techniques are considered to be of particular potential for further development.

Paroxetine for prevention of depressive symptoms induced by interferon-alpha and ribavirin for hepatitis C

BACKGROUND

Whether antidepressants prevent depression during interferon-alpha/ribavirin treatment for hepatitis C virus infection has yet to be established.

AIM

To investigate the use of paroxetine in a prospective, double-blind, placebo-controlled study for this indication.

METHODS

Sixty-one hepatitis C virus-infected patients were randomly assigned to the antidepressant, paroxetine (n = 28), or placebo (n = 33), begun 2 weeks before and continued for 24 weeks during interferon-alpha/ribavirin treatment. Primary endpoints included development of major depression and severity of depressive symptoms measured by the Montgomery Asberg Depression Rating Scale (MADRS).

RESULTS

Rates of major depression during the study were low (17%) and did not differ between groups. Nevertheless, using published MADRS cut-off scores, the percent of subjects who met criteria for mild, moderate or severe depression during interferon-alpha/ribavirin therapy was significantly lower in paroxetine- vs. placebo-treated subjects (P = 0.02, Fisher's exact test). Assignment to paroxetine was also associated with significantly reduced depressive symptom severity. This effect was largely accounted for by participants with depression scores above the median (MADRS > 3) at baseline in whom paroxetine was associated with a maximal reduction in MADRS scores of 10.3 (95% CI: 2.1-18.5) compared with placebo at 20 weeks (P < 0.01). Study limitations included a small sample size and high drop-out rate.

CONCLUSION

This double-blind, placebo-controlled trial provides preliminary data in support of antidepressant pre-treatment in hepatitis C virus patients with elevated depressive symptoms at baseline.

Rat survival to anthrax lethal toxin is likely controlled by a single gene

We examined whether survival of different rat strains administered anthrax lethal toxin is genetically determined. A reproducible test population of first filial generation hybrid rats was bred based on the susceptibility of progenitors to anthrax lethal toxin and to maximize genetic diversity across the strains. These rats were then tested with varying doses of anthrax lethal toxin. We found that all 'sensitive' strains died within 2 h following systemic administration of 240 mug/kg lethal toxin, while one strain survived following a five times higher dose (1.4 mg/kg). The ability of lethal toxin to lyse macrophage cultures derived from the bone marrow of these strains corresponded with in vivo results. We conclude that a rat test population can detect strain differences in response to anthrax lethal toxin. Survival is influenced by the host genome background and is likely due to a single gene with a recessive mode of inheritance.

Risk factors for musculoskeletal injuries in 2-year-old Thoroughbred racehorses

Musculoskeletal injuries (MSI) in racehorses have been identified as the most common cause of lost training days and weeks spent resting at pasture. Several training-, track- and horse-related risk factors have been identified. However, there is no clear understanding of the inter-relationship between these factors. The aim of this longitudinal cohort study was to investigate risk factors for MSI in 2-year-old Thoroughbred racehorses. Australian Thoroughbred trainers were convenience sampled and enrolled in a 27-month longitudinal cohort study. The study population consisted of all 2-year-old Thoroughbred racehorses trained by a participating trainer. Horses were followed from the time of enrollment until the completion of the study or until they were lost to follow-up. Trainers were visited at approximately 14-day intervals to collect training and injury data. Training days were categorised as fast days if the maximum speed during training exceeded 800 m/min. For each horse, the first training period that included one or more fast days was analysed. A multiple logistic regression model was used to determine those horse- and training-related variables that were associated with MSI. Data from 274 horses trained by 14 trainers at five racetracks were analysed. Forty percent of the horses sustained a MSI during their first fast preparation. The average distance trained at speeds >or=800 m/min and the percentages of fast days from the first fast day until the end of the preparation were the only variables associated with MSI. After accounting for these variables there were still significant differences between trainers. This suggests that there are other training-related variables such as the rate of increase in distance trained at speeds >or=800 m/min that may be risk factors for MSI. In addition, other factors such as the level of veterinary involvement and the training centre/racetrack may be risk factors for MSI. More analysis using multi-level modelling is required to determine the relationship between trainer- and track-related risk factors.

Activation of natural killer-like YT-INDY cells by oligodeoxynucleotides and binding by homologous pattern recognition proteins

The present study was designed to examine the binding and signalling effects of single base and CpG dinucleotide phosphodiester (Po) oligodeoxynucleotides (ODN) on the human natural killer (NK)-like cell line (YT-INDY). Single base Po ODN composed of 20-mers of guanosine (dG20), adenosine (dA20), cytosine (dC20) or thymidine (dT20) as well as 'conventional' Po CpG ODN were examined for their ability to bind and activate YT-INDY cells. Binding by dG20 and CpG ODN to YT-INDY cells was saturable and specific. dG20 binding was competitively inhibited by homologous dG20 and heterologous CpG ODN but not by dC20 and dA20. Two different YT-INDY membrane proteins (18 and 29 kDa) were identified by ligand (Southwestern) blotting with biotinylated dG20 and CpG. The specificity of the ODN-binding protein(s) was further confirmed by ODN depletion experiments using a teleost recombinant protein orthologue [nonspecific cytotoxic cells (NCC) cationic antimicrobial protein-1 (ncamp-1)] known to bind CpG and dG20. Cell proliferation and activation studies showed that dG20 and CpG treatment of YT-INDY cells induced cellular DNA synthesis (i.e. G1 to S-phase conversion). This signalling function was accompanied in dG20-treated cells by proliferation 10 h posttreatment. Both dG20 and CpG ODN binding induced a calcium flux in YT-INDY cells within seconds of treatment. These experiments demonstrated that Po single base dG20 and CpG ODN bind to a (potential) new class of cell-surface proteins that mediate the activation of YT-INDY cells.

Thoracolaryngeal reflex latencies in Thoroughbred horses with recurrent laryngeal neuropathy

Electrolaryngeography was used to study the latencies of the thoracolaryngeal adductor reflex in Thoroughbred horses with and without recurrent laryngeal neuropathy (RLN). Latencies were compared in horses with grades 1 and 2 RLN, diagnosed by endoscopy in resting horses. The reliability of the measurements, effect of sedation and correlations of latencies with age of the horse were also studied. There was no effect of sedation on reflex latency periods. The latency of the reflex period measured to a convolved peak of the electromyographic response was significantly different in horses with grades 1 and 2 disease; medians and quartile ranges were 0.067 (0.065-0.073) and 0.072 (0.068-0.074) s, respectively (P<0.05). Significant associations were found between reflex latencies and both horse age and the grade of RLN. Reflex latency measurements are reliable and sensitive, and may assist with the clinical appraisal of Thoroughbred horses with RLN.

Reliability of cardiorespiratory measurements with a new ergospirometer during intense treadmill exercise in Thoroughbred horses

This study investigated the reliability of measurements with a new equine ergospirometer (Quadflow). Heart rate and blood lactate responses during exercise in horses wearing the Quadflow and an open flow mask were also compared. The mean percentage error of the oxygen uptake measurements was 8.2% (range 2.1-12.5%). Percent error for peak expiratory flow rates ranged from 6.1% to 9.4 %, and for minute ventilation from 2.5% to 7.4%. The coefficients of variation of the means of four measurements in two horses exercising continuously at 9.0 m/s were <5% for variables related to pulmonary ventilation, and was 7.7% for oxygen uptake. The Quadflow mask resulted in small increases in blood lactate concentration and relative heart rate during submaximal exercise. It was concluded that between- and within-test reliability statistics for important measurements in equine clinical exercise testing were acceptable for routine use in a veterinary practice or research laboratory.

Single-base oligodeoxyguanosine-binding proteins on nonspecific cytotoxic cells: identification of a new class of pattern-recognition receptors

The present study was designed to identify a possible new class of pathogen-recognition proteins that bind single-base oligodeoxynucleotide (ODN) ligands. Binding by the teleost natural killer cell equivalent [referred to as nonspecific cytotoxic cells (NCC)] was compared with mammalian cells (mouse RAW264.7 cells and human THP-1 cells). The ODN analysed were composed of 20-mers of guanosine (dG20), adenosine (dA20), thymidine (dT20) or cytosine (dC20). Binding studies first determined the 50% saturation levels for NCC (1.25 microg/ml), RAW264.7 (0.2 microg/ml) and THP-1 (0.8 microg/ml). Binding by dG20 to all the three cell types was saturable. Ligand blots of NCC membrane lysates with biotinylated dG20 revealed two different major molecular weight species (16-18 and 29 kDa) of binding proteins. The 29-kDa protein was identified with the help of Western blot analysis using a polyclonal antibody specific to an NCC antimicrobial protein (ncamp-1). The membrane expression of the 29-kDa ncamp-1 was determined by the binding of surface-biotinylated NCC membrane proteins with digoxigenin dG20 followed by immunoprecipitation using anti-digoxigenin agarose beads. The 29 and 14-18 kDa NCC membrane proteins were cross-reactive using Western blot examination with a polyclonal anti-histone 1 antibody. Function studies revealed that dG20 activated a twofold upregulation of membrane binding by homologous dG20-biotin. dG20 also stimulated NCC-increased membrane expression of NCC receptor protein 1. Additional experiments were performed to determine the DNase sensitivity of the different ODN. dG20 appeared to be more resistant to DNase treatment, compared to dC20, dA20 and dT20. The single-base ODN-binding proteins may represent a new class of pattern-recognition receptors that are involved in innate anti-bacterial resistance mediated by NCC.

The effects of overtraining on blood volumes in standardbred racehorses

Red blood cell hypervolaemia has been used for diagnosis of overtraining in racehorses, and has been suggested as a mechanism of this cause of loss of racing performance. The effects of overload training (OLT) on the plasma, blood and red cell volumes were investigated in a prospective study in 12 Standardbred horses. Measurements of blood volumes were made after eight and 32 weeks of an exercise training study. Horses were randomly allocated to OLT and control groups (n=6) after 16 weeks of training. Training duration and intensity were increased more rapidly for the OLT group from week 16, until overtraining was diagnosed in week 32. There were no significant effects of OLT on plasma, blood or total red cell volumes between weeks eight and 32. These volumes significantly decreased with time. Maximal haematocrit after exercise was lower (P<0.05) in the OT group in week 32 (0.57+/-0.003% L/L) than in week eight (0.59+/-0.004 L/L). It was concluded that red cell hypervolaemia was not a mechanism for the decrease in capacity for exercise that occurs with overtraining.

Animal behaviour learning environment: software to facilitate learning in canine and feline behavior therapy

Interactive software has been developed on CD-ROM to facilitate learning of problem formulation, diagnostic methodology, and therapeutic options in dog and cat behavior problems. Students working in small groups are presented with a signalment, a case history, and brief description of the problem behavior as perceived by the client. Students then navigate through the case history by asking the client questions from an icon-driven question pad. Animated video responses to the questions are provided. Students are then required to rate the significance of the questions and answers with respect to the development of the unwelcome behavior. Links to online self-assessments and to resource materials about causation and treatment options are provided to assist students in their decision-making process. The activity concludes with a software-generated e-mail submission that includes the recorded history, diagnosis, and recommended treatment for assessment purposes.

Plasma lactate and uric acid responses to racing in pacing Standardbreds and relationships with performance

Relationships between racing performance and plasma lactate and uric acid concentrations after racing were investigated in pacing Standardbred racehorses. The study was undertaken in order to better understand factors that limit racing performance. Twenty horses were tested after races of 1760 m and 28 horses after races over 2160 m. Blood samples were taken 30-60 min before and 8 and 30 min after a race. There were no significant differences between the race distances for prerace and 8 min postrace plasma lactates. Significant low correlations were obtained for plasma lactate concentration 8 min postrace and the number of race wins (r = 0.29, P = 0.04), number of race placings (1st, 2nd or 3rd; r = 0.34, P = 0.02) and lifetime earnings (r = 0.29, P = 0.04). Net lactate was correlated with the number of race placings (r = 0.31, P = 0.03). There were no significant correlations between performance indices and plasma uric acid concentrations in races of 1760 m. For races over 2160 m, correlations were found between plasma uric acid concentration at 8 min postrace and the number of race wins (r = 0.37, P = 0.06, 95% confidence limits 0-0.65). As well, there was a significant correlation between uric acid concentration at 8 min postrace and lifetime earnings (r = 0.35, P = 0.07, 95% confidence limits 0.06-0.64). Only 10-15% of the variability in retrospective career performance in pacing Standardbreds can be explained by these metabolic markers of the muscle anaerobic response to racing. Plasma lactate and uric acid responses to maximal exercise are unlikely to be useful for evaluating racing performance in pacing Standardbreds in univariate analysis.

Effects of prolonged training, overtraining and detraining on skeletal muscle metabolites and enzymes

Thirteen Standardbred horses trained intensively for 34 weeks and detrained for 12 weeks to investigate the effects of training, overtraining and detraining on muscle metabolites, buffering capacity and enzyme activities (CS, HAD and LDH). After a standardised exercise test to fatigue at 10 m/s (approximately 100% VO2max), there was significant depletion of [ATP], [PCr] and muscle [glycogen] and accumulation of muscle and plasma [lactate], [NH3] and elevated muscle temperature. After training, associated with increased run time to fatigue (148%), there was reduced depletion of muscle [glycogen] and increased [NH3] and muscle temperature at fatigue. Training resulted in increased muscle buffering capacity (19%) and activities of CS (29%) and HAD (32%) and reduced glycogen utilisation (1.32 mmol/s in week 1 to 0.58 mmol/s in week 32). Plasma [lactate] at fatigue increased with training as opposed to muscle [lactate] implying enhanced ability to remove lactate from muscle. Overtraining resulted in reduced run time and associated effects in overtrained horses. While muscle [glycogen] prior to exercise was lower in overtrained horses, glycogen utilisation/s was not reduced and it may not, therefore, have caused the reduced run time. Prolonged high intensity training caused primarily aerobic adaptations and poor performance associated with overtraining may not be due to metabolic disturbances.

Heart rate and blood lactate responses during exercise in preparation for eventing competition

The aim of this study was to investigate the heart rate and blood lactate responses to exercise in event horses in normal training, and to compare them to those encountered in eventing competition. It was hypothesised that the responses during exercise in the course of training for CCI*** events would be significantly different from those of the Cross-Country day. Heart rates and blood lactate concentrations were measured in 13 elite event horses after intense exercise sessions conducted during the late stages of preparation for CCI*** or CCI**** 3-day-event competition. Mean +/- s.d. heart rate during exercise was 138 +/- 17 beats/min and mean blood lactate concentration after exercise was 1.0 +/- 0.6 mmol/l. These values were compared to heart rates and blood lactate concentrations recorded during and after a CCI*** Cross Country course using unpaired t tests (unequal variances) and 99.9% confidence interval analysis. Mean heart rates during and blood lactate concentrations after the competition were 195 +/- 8 beats/min and 10.2 +/- 4.2 mmol/l. The 99.9% confidence intervals were 183-207 beats/min and 7.7-12.6 mmol/l. Heart rates and blood lactate concentrations recorded during exercise sessions were significantly lower than competition values (P<0.001) and lay outside 99.9% confidence intervals for most horses. Only one horse achieved heart rates and blood lactate concentrations during exercise sessions that were similar to those occurring in competition. The intensity of exercise during normal training sessions was much lower than during competition, suggesting that many event horses are not appropriately trained.

Metabolic responses to submaximal field exercise tests and relationships with racing performance in pacing Standardbreds

This study was undertaken to invesigate the application of submaximal field tests in assessment of performance. A submaximal field exercise test consisting of 2 bouts of pacing for 1600 m, with 5 min rest or walking between runs was performed on Standardbred racehorses at 2 training centres (A and B). Performance indices were compiled for each horse: number of race starts, number of race wins, number of race placings (1, 2 or 3), and lifetime earnings. Regression analysis was conducted to describe the relationship between plasma lactate concentrations and speed for tests one, 2 and pooled results. Using the regression equation, observed (measured) minus expected (predicted) (O-E) lactate concentrations for tests were calculated and plotted against performance indices to determine their relationship. For stables A and B the association between lactate and velocity for the 2 runs was best described by the exponential equations: y = 0.0014(e07306x) (r2 = 0.54, P<0.001) and y = 0.002(e06812x) (r2 = 0.42, P<0.001), respectively, where y is lactate concentration (mmol/l) and x is speed (m/s). For the pooled results for heat 1 and heat 2 for stables A and B the relationship between lactate and velocity was best described by an exponential equation y = 0.0016(e07117x) (r2 = 0.47, P<0.001). This study found no relationship between (O-E) and performance indices (number of race wins, number of race placings, lifetime earnings and average $/start) at stables A or B for test run 1, 2 or pooled lactates. At stable A, there was a significant association between V(La4) and log lifetime earnings (r = 0.51, P = 0.053) and log average $/start (r = 0.54, P = 0.036). There were no significant correlations at stable B. In conclusion a 2-step determination method of V(La4) is a possible means for studying limits to performance in pacing Standardbred racehorses.

Hyperhydration prior to moderate-intensity exercise causes arterial hypoxaemia

The second day of a 3-day event is the most physically demanding of the 3 days. If this is performed under hot and humid environmental conditions, detrimental effects on cardiovascular and thermoregulatory function and, therefore, on exercise capacity, may occur due to exercise-induced dehydration. We hypothesised that the administration of fluid equivalent to 6% of the horse's bodyweight prior to a simulated second day of a 3-day event would increase plasma volume and limit increases in core temperature. Seven Standardbred geldings underwent a training protocol prior to the study. A standardised exercise test was developed for each horse so that exercise intensity at each phase would be the same percentage of the maximal heart rate for all horses. The exercise test involved 4 phases: Phase A involved 30 min exercise at 3.7 m/s (approximately 25% VO2max); Phase B 4 min exercise at 8 m/s (approximately 60% VO2max); and Phase C 50 min at 3.7 m/s, after which there was a 10 min rest. Phase D involved 14 min at 7.3 m/s (55% VO2max). In a cross-over design, horses were grouped randomly and allocated to either exercise with no fluid (control) or approximately 26 l isotonic fluid by nasogastric tube, 120 min prior to exercise. Arterial and mixed venous blood samples were collected prior to exercise, towards the end of each of the phases and during the rest period. The administration of fluid prior to exercise resulted in a pre-exercise bodyweight gain of 21.3 +/- 1.2 kg. Hyperhydration resulted in a greater degree of arterial hypoxaemia than the control group in Phases B and D, but not in Phases A and C or at rest. During Phases B and D, mean PaO2 values in the horses that received fluid were about 15 torr lower than in the control group, but there were no differences in PaCO2 values between the 2 groups. In both arterial and mixed venous blood, pH and HCO3- were significantly lower in the group that were hyperhydrated. We concluded that the most likely cause of the more severe arterial hypoxaemia in the hyperhydrated group during the intense exercise phase was some degree of pulmonary oedema, from the extravasation of the administered fluid. Hyperhydration prior to exercise may be detrimental to respiratory function and therefore care must be taken in administration of large volumes of fluid prior to exercise.

Progression to AIDS, a clinical AIDS condition and mortality: psychosocial and physiological predictors

BACKGROUND

The primary aim of this study is to examine prospectively the association of stressful life events, social support, depressive symptoms, anger, serum cortisol and lymphocyte subsets with changes in multiple measures of human immunodeficiency virus (HIV) disease progression.

METHODS

Ninety-six HIV-infected gay men without symptoms or anti-retroviral medication use at baseline were studied every 6 months for up to 9 years. Disease progression was defined in three ways using the Centers for Disease Control (CDC) classifications (e.g. AIDS, clinical AIDS condition and mortality). Cox regression models with time-dependent covariates were used, adjusting for control variables (e.g. race, age, baseline, CD4 T cells and viral load, number of anti-retroviral medications).

RESULTS

Higher cumulative average stressful life events and lower cumulative average social support predicted faster progression to both the CDC AIDS classification and a clinical AIDS condition. Higher anger scores and CD8 T cells were associated with faster progression to AIDS, and depressive symptoms were associated with faster development of an AIDS clinical condition. Higher levels of serum cortisol predicted all three measures of disease progression.

CONCLUSIONS

These results suggest that stressful life events, dysphoric mood and limited social support are associated with more rapid clinical progression in HIV infection, with serum cortisol also exerting an independent effect on disease progression.

Dopaminergic and serotonergic activities of imidazoquinolinones and related compounds

The synthesis of 5-(dipropylamino)-5,6-dihydro-4H-imidazo[4,5,1-ij] quinolin-2(1H)-one (5), a potent dopamine D2 agonist showing high dopamine/serotonin (5HT1A) selectivity, is described. Dopaminergic activity is associated with the (R)-enantiomer of 5; the (S)-enantiomer shows no dopaminergic activity. A series of analogues where the imidazolone ring was modified to various 5- or 6-membered heterocyclic rings were prepared. Some of these compounds showed a combination of dopaminergic and serotonergic activity, while one compound, 6-(dipropylamino)-1,2,6,7-tetrahydro-3H,5H-pyrido[3,2,1- ij]quinazolin-3-one (24), was a selective serotonergic agonist. Various analogues of 5 where the dipropylamine substituent was modified were prepared. Most of these showed reduced dopaminergic activity, while several were as potent as 5 at the serotonin 5HT1A receptor. Orientations for the new compounds at dopamine and serotonin receptors are proposed and compared with those of other tricyclic ligands known to have high affinity at these receptors.

Heparin binding site, conformational change, and activation of antithrombin

Alignment of the heparin-activated serpins indicates the presence of two binding sites for heparin: a small high-affinity site on the D-helix corresponding in size to the minimal pentasaccharide heparin, and a longer contiguous low-affinity site extending to the reactive center pole of the molecule. Studies of the complexing of antithrombin and its variants with heparin fractions and with reactive center loop peptides including intermolecular loop-sheet polymers all support a 3-fold mechanism for the heparin activation of antithrombin. Binding to the pentasaccharide site induces a conformational change as measured by circular dichroism. Accompanying this, the reactive center becomes more accessible to proteolytic cleavage and there is a 100-fold increase in the kass for factor Xa but only a 10-fold increase for thrombin, to 6.4 x 10(4) M-1 s-1. To obtain a 100-fold increase in the kass for thrombin requires in addition a 4:1 molar ratio of disaccharide to neutralize the charge on the extended low-affinity site. Full activation requires longer heparin chains in order to stabilize the ternary complex between antithrombin and thrombin. Thus, addition of low-affinity but high molecular weight heparin in conjunction with pentasaccharide gives an overall kass of 2.7 x 10(6) M-1 s-1, close to that of maximal heparin activation.

Activation of nonspecific cytotoxic cells (NCC) with synthetic oligodeoxynucleotides and bacterial genomic DNA: binding, specificity and identification of unique immunostimulatory motifs

We have analyzed the effects of synthetic oligodeoxynucleotides (sODNs) and bacterial DNA (bDNA) on the in vitro activation of NCC. Teleost NCC recognition of DNA appeared to differ from that which occurs in higher vertebrates. NCC contain at least two different receptor specificities for DNA. Both oligodeoxyguanosine 20-mers (dG20) and 5'-TGCTGCTTGTGCTTGTGCTT-3' (4GC-2T) bound specifically to NCC. The existence of different receptor specificities was indicated by reciprocal cold target inhibition experiments. dG20 competed with 4GC-2T binding but sODNs composed of GpC or CpG nests did not compete with recognition by NCC of the dG20. ODN binding by NCC primarily depended on the presence of GpC or CpG nests with a preference for -G- serving as the anchor nucleotide. Secondarily, and similar to models of ODN activation in mammals, palindrome sequences of pu-pu-CpG-py-py activated NCC cytotoxicity. Additional analysis of the requirements for ODN activation indicated that guanosine could not substitute for adenosine as a purine spacer and that CpG motifs containing flanking thymidine (i.e.-GTCpGTT-) augmented the activity of the sODN containing this flanking base. Other evidence for the participation of both G and C in the recognition of specific nucleotides by NCC was that poly-dC20, dA20 or dT20 had no activating properties. Methylation of all cytosine nucleotides within an ODN abrogated activation. A canonical ODN motif of 5'-C/AT/AGCTT-3' can now be suggested for teleosts. Additional studies were done to examine the effects of in vitro treatment of NCC with bDNA. bDNA from three different disease isolates of Streptococcus iniae activated NCC cytotoxicity. Treatment of the bDNA with DNase abrogated the enhancement of cytotoxicity. Also, treatment of NCC with eukaryotic DNA had no effects on cytotoxicity. These studies suggested that NCC recognize bacterial nonmethylated DNA. The consequences of these interactions may be increased innate and acquired anti-bacterial immunity.

Flow cytometry-based assay for determination of teleost cytotoxic cell lysis of target cells

BACKGROUND

The nonradiometric assays previously developed to detect cellular cytotoxic activity have been hindered by many difficulties. Among the problems are the requirement for expensive commercial kits and the use of techniques that produce high background noise and decreased sensitivity. In addition, these assays did not account for bidirectional apoptosis (activation-induced cell death [AICD]). Most attempts to derive cytometry-based cytotoxicity assays have been unsuccessful because individual effectors and targets could not be identified (i.e., "separated") using gating techniques.

METHODS

In the present study, teleost nonspecific cytotoxic (NCC) and mammalian target cells were each sufficiently different in size to identify them by flow cytometry (FCM). Using appropriate gating and discriminator techniques, these two cell populations were differentiated based on scatter properties and propidium iodide (PI) binding. Total capacity for PI binding was obtained by permeabilization of the targets with ice-cold acetone. Spontaneous PI binding was relatively low. This technique detected cytotoxicity at effector-to-target ratios (E:T) of 1:1 and after only 30 min cocultivation.

RESULTS

Tilapia NCC from peripheral blood kill human transformed target cells by necrosis and apoptosis as identified by PI binding. Maximum killing of HL-60 targets (approximately 100%) occurred by 180 min cocultivation. For the same time, the killing of IM-9 did not exceed 60%. Almost 90% of IM-9 targets are lysed following 14 h of cocultivation. The maximum killing of both HL-60 and IM-9 targets was observed at a 25:1 E:T ratio after 14 h. Comparisons of the chromium(>51) release assay with flow detection of cytotoxicity revealed that FCM detected 55% lysis of the target cells compared with 2% cytotoxicity by chromium release, after a cocultivation time of 240 min.

DISCUSSION

FCM detection of (teleost) NCC lysis of target cells using PI uptake is more sensitive than standard chromium release assays. This level of sensitivity was observed because NCC and targets were sufficiently different in size such that they could be resolved by scatter plots. Using FCM, cytotoxicity was detected earlier and at lower E:T ratios than previously reported for chromium release assays. Although tilapia were reported previously to be not capable of lysing IM-9 targets by chromium release detection, the more sensitive method of FCM detected cytotoxicity using PI uptake. HL-60 lysis by tilapia NCC exhibited saturable kinetics but occurred at different times post-cocultivation.

Elevated substance P levels in HIV-infected men

The neuropeptide, substance P, is a potent modulator of neuroimmunoregulation. Substance P and its receptor modulate HIV infection. HIV-seropositive men had significantly higher plasma substance P levels compared with uninfected controls, which were associated with decreased CD16 and CD56 natural killer (NK) cell populations. The changes in plasma substance P levels and decreases in NK subsets did not correlate with CD4 cell levels, but a diurnal pattern was suggested for substance P. The balance between substance P expression and functions of immune cells may be important in the immunopathogenesis of HIV infection.

The non-specific cytotoxic cell receptor (NCCRP-1): molecular organization and signaling properties

The evolutionary precursor to mammalian natural killer cells in teleost fish is called non-specific cytotoxic cells (NCC). NCC collaborate with other non-specific effector mechanisms to provide innate resistance during acute stress responses. The NCC receptor protein (NCCRP-1) contains 238 amino acid residues and is believed to be a type III membrane protein with three distinct functional domains. The antigen-binding domain has been mapped to amino acids nos. 104-119. The intracellular C-terminus contains a high concentration of potential phosphorylation sites (Y, S, T). Indeed, we have shown that activation of NCC by crosslinking of NCCRP-1 leads to receptor tyrosine and serine phosphorylation. The N-terminus of the molecule is also inside the cells and has as well signature amino acids, proline-rich motifs (PRM), that are indicative of functional relevance. The cytokine/hormone receptor-like PRMs are known docking sites for JAK kinases. We have evidence that following activation, NCCRP-1 comes in contact with JAK kinase and as a result of this interaction, STAT 6 is translocated into the nucleus. These results suggest that NCCRP-1 may play a dual role in the activation of NCC: first, as an antigen recognition molecule necessary for target cell lysis, and second, as an initiator of cytokine release from NCC. Both of these processes are required for a competent innate immune response.

Nonspecific cytotoxic cells and innate immunity: regulation by programmed cell death

Although programmed cell death (PCD) and the cellular pathology of apoptosis have been extensively studied in mammals and invertebrates, little is known regarding these important regulatory processes in cold blooded vertebrates, especially teleost fish. In the present review, select immunoregulatory properties of PCD/apoptosis in nonspecific cytotoxic cells (NCC) from catfish and tilapia were identified. The techniques used to define the characteristics of PCD in NCC were DNA ploidy, Annexin-V binding and cellular morphology. Using these procedures, we determined that the biochemical/genetic changes that NCC undergo during PCD are similar to those described in mammalian cells. We hypothesize that one immediate response of NCC to acute stress in teleost fish is the release of apoptosis regulatory factors (ARF) or stress activated serum factors (SASF) into the peripheral blood. These cytokine-like factors activate NCC by protecting them from initiation of: "activation induced cell death" (AICD); from "receptor induced apoptosis"; and from initiation of dexamethasone induced DNA hypoploidy. We predict that the mechanism of these actions is enhanced NCC recycling capacity and initiation of migration of NCC into sites of inflammation. In this review, studies were also summarized regarding the expression and release of "death and survival proteins" by NCC. Although the survey was not exhaustive, we showed that tilapia NCC that were activated in vitro with SASF contained increased levels of two adaptor proteins (i.e. CAS, FADD) and soluble FasL. At present the relevance of expression of the adaptor proteins by NCC is not known, however, additional evidence for the role of FasL in NCC innate immune responses was presented. Interestingly, NCC contained constitutive cytosolic FasL, and activation with tumor cells caused a significant decrease in the cytoplasmic levels of this "death protein". This indicated that FasL in NCC may function as a secretory cytokine-like molecule. Unlike mammalian NK cells and T-cells, activated NCC do not express membrane FasL. A level of phosphatase regulation of NCC apoptosis was indicated by demonstrating a reduced camptothecin induce DNA hypoploidy by pretreatment of NCC with the tyrosine phosphatase inhibitor sodium orthovanadate. This review emphasized the important regulatory functions of PCD/apoptosis for NCC in innate immune responses.

Psychosocial-immune relationships in HIV disease

Human immunodeficiency virus (HIV) is now commonly viewed as a chronic disease, which often consists of a wide array of recurrent and sometimes severe psychosocial stressors. An individual's response to these multiple challenges over time may impact their health. In this article, we review research examining the relationship of psychologic factors (eg, depression, stressful life events, coping, social support) with immune system function and disease course. We also explore some of the potential physiologic pathways that may underlie these types of psychosocial-immune relationships, as well as the effects of psychologic interventions, particularly cognitive-behavioral stress management (CBSM), on the psychosocial, neuroendocrine, and immune functioning of people living with HIV. We conclude by suggesting some areas for future research, particularly the study of HIV-positive women.

Neuroimmunologic aspects of sleep and sleep loss

The complex and intimate interactions between the sleep and immune systems have been the focus of study for several years. Immune factors, particularly the interleukins, regulate sleep and in turn are altered by sleep and sleep deprivation. The sleep-wake cycle likewise regulates normal functioning of the immune system. Although a large number of studies have focused on the relationship between the immune system and sleep, relatively few studies have examined the effects of sleep deprivation on immune parameters. Studies of sleep deprivation's effects are important for several reasons. First, in the 21st century, various societal pressures require humans to work longer and sleep less. Sleep deprivation is becoming an occupational hazard in many industries. Second, to garner a greater understanding of the regulatory effects of sleep on the immune system, one must understand the consequences of sleep deprivation on the immune system. Significant detrimental effects on immune functioning can be seen after a few days of total sleep deprivation or even several days of partial sleep deprivation. Interestingly, not all of the changes in immune physiology that occur as a result of sleep deprivation appear to be negative. Numerous medical disorders involving the immune system are associated with changes in the sleep-wake physiology--either being caused by sleep dysfunction or being exacerbated by sleep disruption. These disorders include infectious diseases, fibromyalgia, cancers, and major depressive disorder. In this article, we will describe the relationships between sleep physiology and the immune system, in states of health and disease. Interspersed will be proposals for future research that may illuminate the clinical relevance of the relationships between sleeping, sleep loss and immune function in humans.

Efficacy of venlafaxine in geriatric depression

Geriatric patients with major depression present clinical challenges not encountered in younger individuals, including a greater incidence of medical comorbidity, higher rates of multiple medication use, changes in drug metabolism due to age or physical illness, and increased sensitivity to antidepressant side effects. Nevertheless, successful treatment of depressive disorders in the elderly improves mental and physical functioning, decreases morbidity and perhaps mortality, and enhances quality of life. Recent research indicates that newer antidepressants are effective for late life depression and safer for older individuals. Among newer antidepressants, venlafaxine has a pharmacological profile that makes it an attractive choice for geriatric patients. It has limited potential to interact with other medications because it only weakly inhibits the cytochrome P450 system and binds to plasma proteins at a low level. Dosing may have to be adjusted for patients with renal failure, but typically not for those with liver disease or other medical conditions. Data from three double-blind and four open clinical trials support the safety and efficacy of venlafaxine for geriatric depression. Patients may experience transient, generally tolerable side effects such as insomnia, nausea, agitation, or dry mouth early in treatment, but more serious problems such as falls or cardiac rhythm disturbances seem to be rare. Treatment emergent hypertension occurs in a small percentage of older patients, generally at doses above 150 mg/day. Finally, emerging data suggest that venlafaxine may be effective for conditions such as stroke, anxiety, and neuropathic pain that frequently accompany depressive disorders in the elderly.

Streptococcus iniae inhibition of apoptosis of nonspecific cytotoxic cells: a mechanism of activation of innate immunity in teleosts

Nonspecific cytotoxic cells (NCC) may provide innate anti-bacterial resistance against Streptococcus iniae infections in tilapia. The mechanism of immunity would be elaboration and release of various cytokines, augmentation of inflammation and amplification of increased antigen processing. To investigate bacterial regulation of NCC function, 2 different processes of cellular pathology were examined: apoptosis and necrosis. Different isolates of S. iniae from diseased teleosts, a dolphin and a human were tested. All isolates were examined for their ability to produce apoptosis and/or necrosis on freshly purified tilapia NCC and on a tilapia continuous cell line (i.e. TMB-8 cells). Two different isolates (9033 and 173) inhibited the outer membrane expression of phosphatidylserine (PS) by NCC, an early sign of apoptosis. This occurred at 4 h post-treatment and lasted throughout the 24 h treatment period. All other isolates either did not differ from control levels or produced a small increase in PS expression by NCC. The early reduction in PS expression occurred concomitantly with increased necrosis associated with nonspecific DNA fragmentation. Two-color flow cytometry (Annexin-V vs propidium iodide staining) demonstrated the specificity of Annexin-V binding. Experiments were also done to determine the effects of S. iniae on TMB-8 cells. Treated TMB-8 cells did not produce appreciable Annexin-V binding. Compared to the ATCC strain, 9033 produced high levels of necrosis-associated DNA fragmentation of TMB-8 cells at 4 and 8 h post-treatment. These data indicated that different isolates of S. iniae may regulate NCC anti-bacterial resistance by causing reduced levels of programmed cell death (PCD), increased necrosis and associated enhancement of inflammatory responses. Understanding the relevance of these bacterial effects on NCC may be an important consideration in the evaluation of isolates used in vaccine/ bacterin production.

Recovery of Streptococcus iniae from diseased fish previously vaccinated with a streptococcus vaccine

Streptococcus iniae was recovered from diseased rainbow trout (Oncorhynchus mykiss, Walbaum) previously vaccinated against streptococcosis. PCR and serological methods indicate the presence of a new serotype in the diseased fish.

Acute mood and thyroid stimulating hormone effects of transcranial magnetic stimulation in major depression

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) has recently been demonstrated to have antidepressant effects. Some work suggests that rTMS over prefrontal cortex administered to healthy individuals produces acute elevations of mood and serum thyroid-stimulating hormone (TSH). We sought to determine whether single rTMS sessions would produce acute mood and serum TSH elevations in subjects with major depressions.

METHODS

Under double-blind conditions et al 14 medication-free subjects with major depression received individual sessions of either active or sham rTMS. rTMS was administered over the left prefrontal cortex at 10 Hz et al 100% of motor threshold, 20 trains over 10 min. Immediately before and after rTMS sessions, subjects' mood was rated with the Profile of Mood States (POMS) and the 6-Item Hamilton Depression Scale, and blood was drawn for later analysis of TSH. Subjects and raters were blind to treatment assignment.

RESULTS

The group receiving active stimulation manifested significantly greater improvement on the POMS subscale of Depression (p < or = .0055) and a trend toward greater improvement on the modified Hamilton Rating (.05 < p < or =.1). No hypomania was induced. The change in TSH from pre- to post-rTMS was significantly different between active and sham sessions.

CONCLUSIONS

This blinded, placebo-controlled trial documents that individual rTMS sessions can acutely elevate mood and stimulate TSH release in patients experiencing major depressive episodes.

Double-blind, placebo-controlled comparison of imipramine and paroxetine in the treatment of bipolar depression

OBJECTIVE

This study compared the efficacy and safety of paroxetine and imipramine with that of placebo in the treatment of bipolar depression in adult outpatients stabilized on a regimen of lithium.

METHOD

In a double-blind, placebo-controlled study, 117 outpatients with DSM-III-R bipolar disorder, depressive phase, were randomly assigned to treatment with paroxetine (N=35), imipramine (N=39), or placebo (N=43) for 10 weeks. In addition to lithium monotherapy, patients may have received either carbamazepine or valproate in combination with lithium for control of manic symptoms. Patients were stratified on the basis of trough serum lithium levels determined at the screening visit (high: >0.8 meq/liter; low: </=0.8 meq/liter). Primary efficacy was assessed by change from baseline in scores on the Hamilton Rating Scale for Depression and the Clinical Global Impression illness severity scale.

RESULTS

Differences in overall efficacy among the three groups were not statistically significant. For patients with high serum lithium levels, antidepressant response at endpoint also did not significantly differ from placebo. However, both paroxetine and imipramine were superior to placebo for patients with low serum lithium levels. Compared to imipramine, paroxetine resulted in a lower incidence of adverse events, most notably emergence of manic symptoms.

CONCLUSIONS

Antidepressants may not be useful adjunctive therapy for bipolar depressed patients with high serum lithium levels. However, antidepressant therapy may be beneficial for patients who cannot tolerate high serum lithium levels or who have symptoms that are refractory to the antidepressant effects of lithium.

Doppler sonographic measurements of arterial blood flow and their repeatability in the equine foot during weight bearing and non-weight bearing

In six normal adult horses, pulsed-wave Doppler sonographic inspections were made of the left and right lateral palmar proper digital artery (LPPDA) of each thoracic limb. Using a two-period, crossover design with repeated measures, each LPPDA was inspected on four occasions throughout the day over a 7 hour period and, on each occasion, with the limb weight bearing and non-weight bearing. In comparison with the observations made during weight bearing, there were significant increases (P<0.001) in blood-flow velocities when the limb was non-weight bearing. There was no relationship between blood velocities and the time of day, the order in which the inspections were made, resting heart rate, age of the horse, or hoof angle. In both weight bearing and nonweight bearing, the Doppler waveform demonstrated a systolic peak followed by at least two diastolic peaks and an end diastolic plateau. Horses that moved least during sonographic inspections had the lowest co-efficients variation.

Nonradiometric detection of cytotoxicity of teleost nonspecific cytotoxic cells

The development of a sensitive, rapid and reliable nonradiometric cytotoxicity assay would significantly facilitate studies of teleost nonspecific cytotoxic cells. Such an assay would not require handling and disposal of radionuclides and it would not depend on secondary enzyme or colorimetric determinations. The requirements for this assay would consist of a one-step binding protocol which could detect early target cell membrane lesions and at very low effector:target cell ratios. In this chapter, we have developed a flow cytometry based cytotoxicity assay utilizing the uptake of propidium iodide (PI) into cells containing damaged (i.e. permeabilized) cell membranes. The basis of detection of cellular damage depended on flow discrimination of targets from effector cells by establishing 'scatter' gates from these mixtures. Teleost (catfish) anterior kidney NCC were mixed with human transformed targets (IM-9 and HL-60 cells) at effector:target cell ratios of 1, 5 and 10 and PI uptake was determined at 3 and 14 hours post-incubation. Percent specific uptake (PSU) was calculated by determining total binding capacity (TBC) (i.e. uptake of PI by cold acetone permeabilized target cells) and spontaneous binding capacity (SBC) (i.e. PI uptake by target cells incubated in media w/o effectors). This was represented by the formula PSU = [T - SBC/TBC - SBC] x 100 where T is the PI uptake of targets following addition of effector cells. Using this technique, NCC initiated target cell permeabilization as early as 30 minutes co-incubation (25:1 E:T ratio) and damaged membranes were detected in mixtures containing as few as 1:1 effector:target cell ratios. At 5:1 E:T ratios, greater than 50 PSU was determined following 14 hours co-incubation. Using these criteria, a new and sensitive cytotoxicity assay has been developed to determine NCC activity.

Methods for cell cycle analysis and detection of apoptosis of teleost cells

Flow cytometric techniques have not been previously used on a routine basis to study teleost cell growth and development. In the present chapter, flow instrumentation and cell preparation protocols are given in order to provide evaluation criteria characteristic of different phases of the cell cycle. Flow cytometry is used as an analytical and diagnostic tool to measure DNA ploidy as well as to measure alterations in cell cycle profiles characteristic of random DNA fragmentation (necrosis) compared to patterned DNA cleavage (apoptosis). The types of information obtained by flow analysis include the visualization of cell subpopulations with differing DNA content. For each identified nuclei subpopulation, the parameters of population size, fractions of nuclei in each phase of the cell cycle and computation of DNA ratios can be discerned. Data are presented of ex vivo prepared teleost nonspecific cytotoxic cells (NCC) at resting phase compared to NCC undergoing DNA hypoploid changes characteristic of apoptosis. These cells are compared with a teleost tissue cultured cell line maintained under optimum cell growth conditions versus cells undergoing necrotic cellular pathology. Finally, the requirements for optimum flow analysis are described. Techniques including gating strategies, voltage and gain settings, discrimination options and data collection and interpretation are provided.