Mobile phone use and brain tumour risk - COSMOS, a prospective cohort study

BACKGROUND

Each new generation of mobile phone technology has triggered discussions about potential carcinogenicity from exposure to radiofrequency electromagnetic fields (RF-EMF). Available evidence has been insufficient to conclude about long-term and heavy mobile phone use, limited by differential recall and selection bias, or crude exposure assessment. The Cohort Study on Mobile Phones and Health (COSMOS) was specifically designed to overcome these shortcomings.

METHODS

We recruited participants in Denmark, Finland, the Netherlands, Sweden, and the UK 2007-2012. The baseline questionnaire assessed lifetime history of mobile phone use. Participants were followed through population-based cancer registers to identify glioma, meningioma, and acoustic neuroma cases during follow-up. Non-differential exposure misclassification was reduced by adjusting estimates of mobile phone call-time through regression calibration methods based on self-reported data and objective operator-recorded information at baseline. Hazard ratios (HR) and 95% confidence intervals (CI) for glioma, meningioma, and acoustic neuroma in relation to lifetime history of mobile phone use were estimated with Cox regression models with attained age as the underlying time-scale, adjusted for country, sex, educational level, and marital status.

RESULTS

264,574 participants accrued 1,836,479 person-years. During a median follow-up of 7.12 years, 149 glioma, 89 meningioma, and 29 incident cases of acoustic neuroma were diagnosed. The adjusted HR per 100 regression-calibrated cumulative hours of mobile phone call-time was 1.00 (95 % CI 0.98-1.02) for glioma, 1.01 (95 % CI 0.96-1.06) for meningioma, and 1.02 (95 % CI 0.99-1.06) for acoustic neuroma. For glioma, the HR for ≥ 1908 regression-calibrated cumulative hours (90th percentile cut-point) was 1.07 (95 % CI 0.62-1.86). Over 15 years of mobile phone use was not associated with an increased tumour risk; for glioma the HR was 0.97 (95 % CI 0.62-1.52).

CONCLUSIONS

Our findings suggest that the cumulative amount of mobile phone use is not associated with the risk of developing glioma, meningioma, or acoustic neuroma.

Depression and Anxiety in Adolescents During the COVID-19 Pandemic in Relation to the Use of Digital Technologies: Longitudinal Cohort Study

BACKGROUND

Adolescents are susceptible to mental illness and have experienced substantial disruption owing to the COVID-19 pandemic. The digital environment is increasingly important in the context of a pandemic when in-person social connection is restricted.

OBJECTIVE

This study aims to estimate whether depression and anxiety had worsened compared with the prepandemic period and examine potential associations with sociodemographic characteristics and behavioral factors, particularly digital behaviors.

METHODS

We analyzed cross-sectional and longitudinal data from a large, representative Greater London adolescent cohort study: the Study of Cognition, Adolescents and Mobile Phones (SCAMP). Participants completed surveys at T1 between November 2016 and July 2018 (N=4978; aged 13 to 15 years) and at T2 between July 2020 and June 2021 (N=1328; aged 16 to 18 years). Depression and anxiety were measured using the Patient Health Questionnaire and Generalized Anxiety Disorder scale, respectively. Information on the duration of total mobile phone use, social network site use, and video gaming was also collected using questionnaires. Multivariable logistic regression was used to assess the cross-sectional and longitudinal associations of sociodemographic characteristics, digital technology use, and sleep duration with clinically significant depression and anxiety.

RESULTS

The proportion of adolescents who had clinical depression and anxiety significantly increased at T2 (depression: 140/421, 33.3%; anxiety: 125/425, 29.4%) compared with the proportion of adolescents at T1 (depression: 57/421, 13.5%; anxiety: 58/425, 13.6%; P for 2-proportion z test <.001 for both depression and anxiety). Depression and anxiety levels were similar between the summer holiday, school opening, and school closures. Female participants had higher odds of new incident depression (odds ratio [OR] 2.5, 95% CI 1.5-4.18) and anxiety (OR 2.11, 95% CI 1.23-3.61) at T2. A high level of total mobile phone use at T1 was associated with developing depression at T2 (OR 1.89, 95% CI 1.02-3.49). Social network site use was associated with depression and anxiety cross-sectionally at T1 and T2 but did not appear to be associated with developing depression or anxiety longitudinally. Insufficient sleep at T1 was associated with developing depression at T2 (OR 2.26, 95% CI 1.31-3.91).

CONCLUSIONS

The mental health of this large sample of adolescents from London deteriorated during the pandemic without noticeable variations relating to public health measures. The deterioration was exacerbated in girls, those with preexisting high total mobile phone use, and those with preexisting disrupted sleep. Our findings suggest the necessity for allocating resources to address these modifiable factors and target high-risk groups.

Reduced incidence of tick paralysis cases in dogs and cats at two emergency clinics in South-East Queensland since 2015: new generation prophylactics as possible explanatory variables

INTRODUCTION

This study aimed to determine the incidence of canine and feline tick paralysis cases presenting to two veterinary emergency hospitals before and after the introduction of new generation prophylactic acaricides.

METHODS

This was a retrospective study, investigating the number of tick paralysis cases presenting to two emergency and critical care veterinary hospitals in South-East Queensland, from 2008 to 2021. A total of 10,914 dogs and 3696 cats were included over the course of the study. To assess if the introduction of new generation prophylactics in 2015 has coincided with any variation in case numbers, data for each species were analysed graphically and numerically in the first instance, then interrupted time series analyses were performed for the dog and cat data independently.

RESULTS

Accounting for seasonal and climatic variation, we estimated a 54.8% reduction in dog (95% CI 45.3%-62.7%) and 44% reduction in cat (95% CI 19.5%-46%) tick paralysis cases presenting to these two clinics. This reduction corresponded with the timing of new generation prophylactic agents being introduced, including isoxazolines and imidacloprid/flumethrin impregnated collars.

CONCLUSION

In the population studied, a significant reduction in the incidence of tick paralysis cases treated by veterinarians has occurred from 2015 onwards and was found to be associated with the timing of the release of new generation acaricidal products.

Factors influencing dairy cattle farmer use of antimicrobials on farms in New South Wales, Australia

Antimicrobial use (AMU) in the food chain is a potential driver of antimicrobial resistance. Despite Australia's strong regulation of AMU limited to veterinary prescriptions, a proportion of empirical antimicrobial treatments are administered by dairy farmers to manage common cattle health problems. This cross-sectional survey identified key influences on AMU by dairy cattle farmers within New South Wales, Australia, to detect opportunities for antimicrobial stewardship (AMS) engagement. The study identified existing relationships, resources and attitudes of the dairy farmers that could be optimised for on-farm AMS strategies. Farmers were most highly influenced by veterinary advice and clinical signs of the animal followed by the withholding period and the potential for antimicrobial resistance development. Farmers' high confidence regarding their own knowledge of antimicrobials (>90%), their high regard for veterinary advice (>90%) and high rate of veterinary health care plan use (69%) provides a strong framework to build the profile and practice of AMS on dairy farms. Positive engagement by dairy farmers (survey response of 20%), was achieved by working with the NSW Food Authority. Despite respondents reporting low reliance on formal (government and commercial) organisations for information about AMU, their engagement demonstrates an opportunity for groups with unparalleled access to dairy farmers to drive AMS. An association between frequent use of veterinary advice and respondents keeping ceftiofur on-farm requires further investigation. Quantitative and qualitative analysis of on-farm resources, decision-making, and practices is required to understand how practices relate to veterinary advice and accepted standards of appropriate AMU on dairy farms.

SnakeMap: four years of experience with a national small animal snake envenomation registry

SnakeMap is a national cloud-based, veterinary snakebite registry. It was designed to prospectively collect data of the clinical circumstances and temporospatial information on cases of snake envenomation in dogs and cats. We herein introduce the project and summarise the data from the first 4 years of SnakeMap. The registry is a veterinary community-based online database allowing case entry from veterinary hospitals across Australia. Registry data comprise hospital characteristics, patient characteristics, envenoming snake type, treatment and outcome variables, including time and geolocation of the snake bite. We present summative information on select key variables from the SnakeMap registry (1 July 2015 to 30 June 2019). Twenty-eight hospitals from 6 states/territories entered 624 cases into the registry, including 419 dogs (67%) and 205 cats (33%). Bite time was available in 216 animals of which 90 (42%) were reported to be bitten in the 3 hours between 03:00 pm and 05:59 pm; median bite to presentation interval was 60 (interquartile range [IQR] 30, 211) minutes in dogs and 95 (IQR 41, 238) minutes in cats. Bites occurred in the owner's yard in 356 dogs (85%) and 53 cats (26%). A snake venom detection kit was used in 172 cases (28%) and antivenom was administered in 523 cases (85%). Most animals (n = 534, 88%) survived to discharge (median hospitalisation of 25 [IQR 16, 62] hours). SnakeMap effectively collects relevant clinical data from dogs and cats with presumed snake bite and provides locally specific information on the epidemiology of snake envenomation in small animals.

Dairy goat producers' understanding, knowledge and attitudes towards biosecurity and Q-fever in Australia

The Australian dairy goat sector is an emerging animal industry undergoing rapid expansion. Limited information is available within this industry in relation to socio-demographic characteristics and biosecurity implementation. Q-Fever, caused by the bacterium Coxiella burnetii, is a zoonotic disease endemic in Australia, with a range of domestic and wild-animal reservoir species, including goats, with infected pregnant goats posing a significant public health risk. The aim of the current study was to investigate the socio-demographics of Australian dairy goat producers, their biosecurity implementation and levels of understanding, knowledge and attitudes towards Q-Fever. To achieve this aim, a cross-sectional study was conducted, using an online survey and follow-up semi-structured interviews among dairy goat producers. A total of 106 goat producers participated in the online survey (35.3% response rate) and 14 participated in the semi-structured interviews. Findings from this study suggest that most goat producers implement biosecurity practices related to direct animal husbandry, such as separating sick goats (86%), vaccinations (79%) and providing separate kidding space (75%); and, practices minimizing the risk of disease introduction, such as maintaining boundary fences (86%) and isolating incoming animals (67%). However, implementation of other biosecurity practices, such as keeping records of visitors and visitor biosecurity requirements, was inadequate. Furthermore, this study identifies a deficit of knowledge and understanding surrounding Q-Fever in the Australian dairy goat sector, and a disconnect between producers' perception of risk and implementation of known appropriate biosecurity measures. The research has identified that producers rely on 'trusted' community networks to provide advice on biosecurity implementation, due to a perceived absence of industry-specific, reputable information sources. Producers identified those outside of these networks as the 'other'. The creation of this other allows producers to deflect responsibility for individual biosecurity on to the other. A multifaceted approach is necessary to increase knowledge, understanding and perception of risk surrounding Q-fever, and promote positive uptake of biosecurity measures, for improved outcomes for animal and human health.

Durch die kontinuierliche Blutdruckmessung lässt sich ein transienter orthostatischer Blutdruckabfall bei idiopathischer REM-Schlaf-Verhaltensstörung nachweisen

Ziel der Studie Es gibt wenige Daten zum orthostatischen Blutdruck (BD) Verhalten und Veränderungen der Herzratenvariabilität (HRV) bei idiopathischer REM-Schlaf-Verhaltensstörung (iRBD). Unsere Hypothese war, dass orthostatische BD Veränderungen vorübergehend sind.

Methodik Wir untersuchten 16 männliche iRBD Patienten und 15 altersgematchte männliche Kontrollprobanden (HC) im Hinblick auf eine Dysautonomie, HRV und kontinuierliche BD Messung während der Kipptischuntersuchung.

Ergebnisse Die BD Abfälle in den ersten 5 Minuten Stehzeit waren bei iRBD Patienten signifikant größer. IRBD Patienten hatten häufiger eine reduzierte respiratorische Sinusarrhythmie (RSA).

Schlussfolgerungen Mittels kontinuierlicher BD Messung ließen sich transiente orthostatische BD Abfälle bei iRBD detektieren. Longitudinale Daten werden zeigen, ob diese Änderungen Hinweise für eine periphere sympathoneurale Dysfunktion darstellen und frühe Marker einer späteren orthostatischen Hypotonie sein können.

Autonomic dysfunction of gastric motility in major depression

BACKGROUND

Patients suffering from major depressive disorder (MDD) often complain about somatic symptoms. Cardiac complaints have been examined predominantly. However, gastrointestinal complaints are also reported frequently and are associated with worse outcomes. The research concerning changes in gastric motility of these patients is rather sparse. The aim of our study was to determine dysfunction of gastric motility and gastrointestinal symptoms in MDD. The duration and severity of MDD were examined regarding its influence over gastric emptying.

METHODS

Gastric emptying was determined by a ¹³C-acetate breath test in patients with MDD (n = 29) and healthy control subjects (n = 51). Prior to this, depressive illness was operationalized using external and self-assessment scales (HAMD-21, MADRS, BDI, CGI). Whether the severity or duration of MDD influenced the gastric emptying parameters was examined using Spearman's correlation. In addition, autonomic complaints were recorded by means of an ANS score. Each ANS score item was determined using a Mann-Whitney U or Kruskal-Wallis test concerning the gastric emptying parameters.

RESULTS

There was a significant difference in the parameters of the maximum gastric emptying rate (T_max) and gastric half emptying time T_1/2b between patients with MDD and healthy control subjects (T_max 66.21min vs 53.35min, p < 0.006, T_1/2b 207.59min vs 133.27min, p < 0.005). There was a significant negative correlation between T_max and the severity of MDD determined with the depression rating scales BDI (Spearman's rank - 0.521, p = 0.013) and HAMD-21 (r - 0.384, p = 0.048). No correlation was found between the duration of MDD and the maximum gastric emptying rate (r - 0.125, p = 0.519) and gastric half emptying time (r - 0.62, p = 0.749).

CONCLUSION

Gastrointestinal motility is significantly impaired in patients with MDD compared to healthy control subjects. Autonomic complaints were indicated frequently in MDD patients. The duration of MDD had no influence over the time of gastric emptying. There was a significant negative correlation between the severity of MDD and T_max, indicating that the T_max was reached earlier with the progression of MDD. The slowing of gastric motility in MDD patients is likely a result of a dysfunction of the autonomic nervous system.

Equine chlamydiosis-An emerging infectious disease requiring a one health surveillance approach

Psittacosis is a rare but potentially fatal zoonosis caused by Chlamydia psittaci, an organism that is typically associated with bird contact. However C. psittaci is capable of infecting other non-avian hosts, such as horses, sheep, cattle and goats. Stud staff and veterinarians have significant exposure to parturient animals and reproductive materials in their routine work. To investigate the zoonotic potential associated with the emergence of C. psittaci as an abortifacient agent in horses, we established a programme of joint human and animal surveillance in a sentinel horse-breeding region in Australia. This programme comprised cross-notification of equine cases to public health agencies, and active follow-up of known human contacts, including stud workers, foaling staff, veterinarians and laboratory staff. We identified no confirmed cases of acute psittacosis despite intensive surveillance and testing of heavily exposed contacts; however, further work in the area is needed.

Transmission of highly virulent community-associated MRSA ST93 and livestock-associated MRSA ST398 between humans and pigs in Australia

Pigs have been recognised as a reservoir of livestock associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in Europe, Asia and North America. However, little is known about the presence and distribution of MRSA in the Australian pig population and pig industry. This study describes the presence, distribution and molecular characteristics of the human adapted Australian CA-MRSA ST93 isolated from pigs, people, and the environment within a piggery. Isolates were subjected to antibiotic susceptibility testing, DNA microarray, whole genome sequencing, multi locus sequence typing, virulence and resistance gene characterization and phylogenetic analysis. MRSA were isolated from 60% (n = 52) of farm workers where 84% of isolates returned ST93 and the rest ST398. Of the thirty-one pig isolates tested further, an equal number of ST398 and ST93 (15 each) and one as ST30-V were identified. Four of six environmental isolates were identified as ST93 and two as ST398. This study has identified for the first time in Australia the occurrence of CA-MRSA ST93 and LA-MRSA ST398 amongst farm workers, pigs, and the farm environment. Comparative genome analysis indicates that ST398 is likely to have been introduced into Australia from Europe or North America. This study also reports the first linezolid resistant MRSA isolated in Australia.

Demographic and preliminary employment data of the first two graduate cohorts from a rural veterinary school

OBJECTIVE

To report initial career experiences and graduate employment destinations 1 and 5 years following graduation of the 67 graduates from the first two graduating classes of the veterinary science program at Charles Sturt University.

DESIGN

Online survey of graduates from the 2010 and 2011 cohorts undertaken 12 months following course completion and descriptive data on graduate practice locations 5 years post-graduation.

PROCEDURE

Questions covered general demographic information, issues relating to work-life balance and factors influencing vocational choices. Descriptive statistics and qualitative responses are reported, with comparisons between continuous variables by two-sample t-test and between categories by Chi-square analyses. Significance was set at P < 0.05. Graduates' locations 5 years after graduation were obtained from veterinary registration details and staff contact with graduates.

RESULTS

Complete survey responses were received from 39 graduates of whom 34 were employed in regional areas, 1 in a very remote area, 3 in major cities and 1 overseas. Hours worked and salary received were consistent with other survey data, with new graduates working in regional practices earning slightly more than those working in metropolitan practices. At 5 years following graduation, the majority (56/61, 92%) remained in rural or regional Australian veterinary practices, with a further five graduates overseas and one lost to follow-up.

CONCLUSION

This study supported the selection criteria and educational approaches at CSU in establishing most of the new graduates in rural and regional mixed veterinary practice.

Epidemiological investigation of grass seed foreign body-related disease in dogs of the Riverina District of rural Australia

OBJECTIVE

To characterise disease presentations caused by grass seed foreign body-related disease (GSFBD) in dogs, identify predisposing risk factors and suggest effective prevention strategies.

METHODS

A retrospective, case-control, telephone survey was conducted to obtain information on GSFBD in dogs from the Riverina district of New South Wales (NSW). Additionally, retrospective case records were obtained from Wagga Wagga Veterinary Hospital and Charles Sturt University Veterinary Teaching Hospital over the period July 2006 to October 2011. Signalment, history, investigative strategies, location and severity of lesion(s), cost of therapy, length of hospitalisation, recurrence rate and microbiology data were recorded.

RESULTS

Cases (473 dogs) meeting stringent inclusion criteria were identified. GSFBD comprised 2.0% of hospital presentations. Breeds with high-density coats were overrepresented. Otitis externa was the most common manifestation of GSFBD in the general practice (47%). In the referral practice pyothorax was the most common entity (34%). In both practices the range of clinical manifestations was broad, including a small number of dogs with catastrophic intracranial disease. Univariable and multivariable logistic regression analyses demonstrated dogs with GSFBD had 3-fold greater odds of having medium coats than short coats and 5-fold less odds of being groomed.

CONCLUSIONS AND CLINICAL RELEVANCE

Grass seeds are a major cause of disease in the dogs of south-west rural NSW, with presentations ranging from mild lameness to severe neurological disease. Some protection from GSFBD was achieved with frequent grooming. Clipping or coat searching without grooming was ineffective as a prevention strategy.

THE EFFECT OF MATURITY ON HEART RATE RESPONSES DURING TRAINING AND TESTING IN POSTPUBESCENT FEMALE VOLLEYBALL PLAYERS

The aim of this study was to examine the effect of maturity, assessed as difference between chronological age and age at peak height velocity, on heart rate (HR) responses to maximal and submaximal laboratory and field exercises. Twenty-eight postpubescent female volleyball players participated in the present study (age 13.8 (0.6) yr, body mass 62.5 (8.2) kg and height 1.73 (0.05) m; mean (standard deviation)). They were divided into two groups with regards to their maturation: less matured (LM) and more matured (MM). In laboratory, HR was recorded during 5 min rest, physical working capacity in heart rate 170 bpm, 3 min step test, 30 s Bosco test and Wingate anaerobic test (WAnT) were performed. In field, a 70 min training session (consisted by three parts: warm-up, 1 x 1 drills and team drills) was monitored and 20 m shuttle run endurance test was performed. There was significant difference between LM and MM groups over HR responses (%HR reserve, %HRR) to exercise training (F(2,21) = 6.08, p = 0.008, η2 = 0.37). There was a main effect of part session of exercise program on HR responses with the highest intensity recorded in 1 x 1 drills (-75% HRR) and the lowest in team drills (-60% HRR in LM and -65% HRR in MM). There was also a moderate effect of maturity on HR during cycling against 90 W and in the WAnT, and small effect on HR during cycling against 60 W, in the end of the step test, Bosco test and running endurance test, where the highest scores were recorded in LM. Based on the findings of the present study, it was concluded that maturity exerted an effect of small to moderate magnitude on H R responses in a laboratory setting and this should be taken into account by coaches and trainers when evaluating physiological characteristics.

In vitro assessment of aiming bias in the frontal plane during orthopaedic drilling procedures

Drilling trials were performed using drilling boards incorporating pairs of 22 mm polyethylene tubes mounted horizontally. The tubes were premarked with 20, 0.5 mm deep notches along the centre of their upper surface representing the starting point for each drilling trial. Volunteers were instructed to drill 20 straight holes across the tube until they penetrated both walls. Kirschner wires were inserted through each of the drill holes until they made indentations into the base board. Deviation of each mark from mid-line was measured using digital callipers. The measured values were used to calculate deviation angles to the left (negative values) or right (positive values). Trials were performed with the drill and guide held in the surgeon's line-of-sight (LOS) and with 300 mm offset (OFF). A systematic error (aiming bias) was identified in all individuals. Overall, left-hander's drilling action was skewed to the left and right-hander's drilling action was skewed to the right. Using LOS technique, mean overall bias was 2.3° (range 0°-7.7°) to the left for left-handers and 1.5(o) (range 0.3°-3.1°) to the right for right-handers. Surprisingly, aiming bias was greater for LOS than for OFF, although the difference for this comparison was not statistically significant.

Investigation of rhythms of secretion and repeatability of plasma adrenocorticotropic hormone concentrations in healthy horses and horses with pituitary pars intermedia dysfunction

REASONS FOR PERFORMING STUDY

There is little published information on whether measurement of plasma ACTH concentration at a single timepoint is a repeatable indicator of pituitary pars intermedia dysfunction (PPID).

OBJECTIVES

To determine whether ultradian or circadian fluctuations in ACTH production influence plasma ACTH concentration in normal horses and horses with PPID.

STUDY DESIGN

Prospective observational study.

METHODS

Plasma ACTH concentration in 8 non-PPID horses and 8 horses with PPID was measured at 08.00, 11.00, 14.00 and 17.00 h on 5 nonconsecutive days within a 3 week period. In addition, at 08.30 h on one day, 6 samples were collected from each horse at precisely 5 min intervals over a period of 25 min. Descriptive and graphical analysis was performed and a linear mixed effects model was fitted to assess the effect of time of day on ACTH concentration in non-PPID and PPID horses.

RESULTS

Evidence of ultradian fluctuation in ACTH production was not identified in either non-PPID or PPID horses. Evidence for circadian fluctuation was identified in non-PPID horses; plasma ACTH concentrations were highest at 08.00 h and decreased through the day. There was no evidence of circadian fluctuation in PPID horses. In non-PPID horses, the magnitude of circadian changes in ACTH concentration was smaller than variations in concentration that occurred at random. Intrahorse variability of ACTH concentration was greater in PPID horses than in non-PPID horses.

CONCLUSIONS

Ultradian and circadian fluctuations in ACTH concentration are unlikely to influence clinical decision making; however, variations of potential clinical relevance do occur in individual horses, for reasons that remain to be determined, and increase in magnitude with progression of PPID. Results of the current study indicate that when an ACTH concentration between 19 and 40 pg/ml is measured, further testing should be considered to increase the accuracy of PPID diagnosis.

Effects of metformin hydrochloride on blood glucose and insulin responses to oral dextrose in horses

REASONS FOR PERFORMING STUDY

Metformin is a potential therapeutic agent for the treatment of insulin resistance (IR). In laboratory animals, orally administered metformin reduces intestinal glucose absorption and may therefore affect insulinaemic responses to oral carbohydrate ingestion.

OBJECTIVES

To determine whether pretreatment with metformin reduces plasma glucose concentration and insulin responses following consumption of dextrose in horses.

STUDY DESIGN

Therapeutic cross-over study.

METHODS

Seven healthy Standardbred and Thoroughbred geldings were subjected to an oral dextrose challenge test on 4 occasions: with and without metformin, before and after induction of IR with dexamethasone. Metformin was administered by nasogastric tube at 30 mg/kg bwt 1 h before administration of dextrose. Glucose and insulin concentrations in plasma/serum were measured at regular intervals during each test. Linear mixed models were specified for each predetermined outcome variable, and for each model the 'treatment' was included as a fixed effect with 4 categorical levels (none, metformin, dexamethasone and dexamethasone with metformin) and horse accounted for as a random effect.

RESULTS

In healthy horses, the administration of metformin resulted in a statistically significant reduction in peak glucose concentration (P = 0.002), area under the glucose curve (P<0.001) and insulin concentration 120 min after dextrose administration (P = 0.011). Following the induction of IR, administration of metformin was associated with significant differences in peak glucose concentration (P<0.001), the percentage increase in glucose concentration (P = 0.010), the area under the glucose curve (P<0.001) and insulin concentration at 120 min (P = 0.034) and 150 min after dextrose administration (P = 0.014).

CONCLUSIONS

Metformin resulted in reduced glycaemic and insulinaemic responses both in healthy horses and in horses with experimentally induced IR.

POTENTIAL RELEVANCE

Metformin may benefit horses with naturally acquired IR by reducing glycaemic and insulinaemic responses to dietary nonstructural carbohydrates. Further investigations into the mechanisms of action of metformin in horses and controlled clinical trials are warranted.

Effect of surgeon experience on postoperative plasma cortisol and C-reactive protein concentrations after ovariohysterectomy in the dog: a randomised trial

OBJECTIVE

To determine if postoperative C-reactive protein (CRP) or cortisol concentrations were significantly changed between dogs undergoing ovariohysterectomy by an experienced or inexperienced surgeon. As part of the Charles Sturt University teaching program, 45 bitches from an animal shelter were surgically sterilised between March and October 2010.

METHODS

The dogs were randomly assigned to surgeons, with 37 sterilised by veterinary undergraduates and 8 by experienced surgeons. Blood samples were collected preoperatively and at 2, 4 and 6 h postoperatively. A standard midline ovariohysterectomy was performed and detailed records kept.

RESULTS

The median surgery time for experienced surgeons was 17 min versus 87 min for inexperienced surgeons. Anaesthesia time and blood loss were greater among the inexperienced surgeons. The CRP concentration increased significantly postoperatively for all animals (P < 0.001). Bitches sterilised by inexperienced surgeons had a significantly greater rise in CRP at 4 and 6 h post-surgery (P = 0.046). Serum cortisol concentrations were found to increase significantly over time for all animals (P < 0.001), but were not affected by surgeon experience.

CONCLUSION

The results suggest that inexperienced surgeons affect their patients differently to experienced surgeons, potentially through tissue trauma or anaesthetic duration. The lack of difference in the cortisol concentrations reflects the large number of triggers for cortisol release and, potentially, that there was little difference between the groups in terms of perceived pain in the presence of good analgesia. Serum CRP concentration may be a more sensitive measure than serum cortisol of differences in surgical trauma.

Is repeated-sprint ability of soccer players predictable from field-based or laboratory physiological tests?

AIM

The aim of this study was to investigate multiple regression models with prediction equations that would enable a valid estimate of running repeated-sprint ability (RSA) in soccer players from the variables measured in field and laboratory physiological tests.

METHODS

Adolescent soccer players (N=33) performed five field performance tests and two laboratory tests for assessment of muscle strength of legs, sprint ability, anaerobic power and capacity, aerobic power and capacity, and running economy. These tests served as potential predictors of RSA. RSA was assessed by a intermittent anaerobic running test (IAnRT) consisted of ten 20 m sprints.

RESULTS

Multiple regression analysis revealed that the mean speed in the 20 m sprint test and the 2 km endurance running test accounted for 89% of total variation in the mean running speed in the IAnRT (VIAnRT) as the indicator of capacity for multiple sprint work (R2=0.89, SEM=0.09 m.s-1). Using the variables from the laboratory tests, the best prediction of the VIAnRT was obtained from the running speed at the ventilatory threshold level (VVT) and anaerobic power (Pmax.kg-1) (R2=0.49, SEM=0.21 m.s-1).

CONCLUSION

Performance in the multiple-sprint exercise as an indicator of RSA can be estimated by the regression equation with two predictors - mean speed in the 20 m sprint and 2 km running test with an error of 4%.

Acute phase protein concentrations in dogs with nasal disease

The concentrations of C-reactive protein (CRP), serum amyloid A, haptoglobin (Hp) and α(1)-acid glycoprotein were measured in dogs with clinical signs of nasal disease and compared with those of healthy dogs in order to determine the expression of these proteins in cases of canine nasal disease. A significant difference (P<0.001) between the symptomatic group and the control group was found for both CRP and Hp. Among the animals with nasal disease, a significant intergroup difference (P<0.05) was found in the expression of Hp between dogs with aspergillosis and those with chronic rhinitis.

Proposal of a 2-tier histologic grading system for canine cutaneous mast cell tumors to more accurately predict biological behavior

Currently, prognostic and therapeutic determinations for canine cutaneous mast cell tumors (MCTs) are primarily based on histologic grade. However, the use of different grading systems by veterinary pathologists and institutional modifications make the prognostic value of histologic grading highly questionable. To evaluate the consistency of microscopic grading among veterinary pathologists and the prognostic significance of the Patnaik grading system, 95 cutaneous MCTs from 95 dogs were graded in a blinded study by 28 veterinary pathologists from 16 institutions. Concordance among veterinary pathologists was 75% for the diagnosis of grade 3 MCTs and less than 64% for the diagnosis of grade 1 and 2 MCTs. To improve concordance among pathologists and to provide better prognostic significance, a 2-tier histologic grading system was devised. The diagnosis of high-grade MCTs is based on the presence of any one of the following criteria: at least 7 mitotic figures in 10 high-power fields (hpf); at least 3 multinucleated (3 or more nuclei) cells in 10 hpf; at least 3 bizarre nuclei in 10 hpf; karyomegaly (ie, nuclear diameters of at least 10% of neoplastic cells vary by at least two-fold). Fields with the highest mitotic activity or with the highest degree of anisokaryosis were selected to assess the different parameters. According to the novel grading system, high-grade MCTs were significantly associated with shorter time to metastasis or new tumor development, and with shorter survival time. The median survival time was less than 4 months for high-grade MCTs but more than 2 years for low-grade MCTs.

Short-term effects of transjugular intrahepatic shunt on cardiac function assessed by cardiac MRI: preliminary results

The purpose of this study was to assess shortterm effects of transjugular intrahepatic shunt (TIPS) on cardiac function with cardiac magnetic resonance imaging (MRI) in patients with liver cirrhosis. Eleven patients (six males and five females) with intractable esophageal varices or refractory ascites were imaged with MRI at 1.5 T prior to, within 24 h after, and 4-6 months after TIPS creation (n = 5). Invasive pressures were registered during TIPS creation. MRI consisted of a stack of contiguous slices as well as phase contrast images at all four valve planes and perpendicular to the portal vein. Imaging data were analyzed through time-volume curves and first derivatives. The portoatrial pressure gradient decreased from 19.8 + or = 2.3 to 6.6 + or = 2.3, accompanied by a nearly two fold increase in central pressures and pulmonary capillary wedge pressure immediately after TIPS creation. Left and right end diastolic volumes and stroke volumes increased by 11, 13, and 24%, respectively (p\0.001), but dropped back to baseline at follow-up. End systolic volumes remained unchanged. E/A ratios remained within normal range. During follow-up the left ventricular mass was larger than baseline values in all patients, with an average increase of 7.9 g (p\0.001). In conclusion, the increased volume load shunted to the heart after TIPS creation transiently exceeded the preload reserve of the right and left ventricle, leading to significantly increased pulmonary wedge pressures and persistent enlargement of the left and right atria. Normalization of cardiac dimensions was observed after months together with mild left ventricular hypertrophy.

Deltoid muscle fiber characteristics in adolescent and adult wrestlers

AIM

The aim of the present study was to examine the adaptation of myosin heavy chain (MHC) isoforms, capillary density and fiber cross sectional area (CSA) of deltoid muscle in adolescent and adult elite Greco-Roman wrestlers.

METHODS

Eighteen Greco-Roman wrestlers were divided into two groups: adolescents included 10 athletes (group A) between 14-18 years of age (15.4+/-1.3 yrs) and adults included 8 athletes (group B) between 20-27 years (23.5+/-2.6 yrs). Histochemical analyses were used to determine the muscle fiber type distribution and the muscle fiber cross sectional area. MHC isoform composition was determined with protein electrophoresis, while capillary density (capillary to fiber ratio and capillaries per mm2) analysis was performed with a-amylase Periodic and Schiff staining.

RESULTS

Adolescents demonstrated a significantly higher percentage of type I fibers (P<0.05) and type I fiber area (P<0.05) compared to the adults. The percentage of type IIa fiber area were significantly higher in adult wrestlers (P<0.05). MHC I isoforms was significantly higher in adolescents (P<0.05), whereas the MHC isoforms of IIa and IIx did not differ between groups. The capillary density (mm2) were significantly higher (P<0.05) in adolescents compared to adults.

CONCLUSION

Our findings suggest that the observed muscle fiber profile in the deltoid muscle of wrestlers may represent an adaptation based on the mechanical and biochemical demands of the long-term training. Such adaptations are linked to the specific characteristics of the training program, the level and the previous training experience of the wrestlers.

Vascular hyporesponsiveness to angiotensin II in rats with CCl(4)-induced liver cirrhosis

BACKGROUND

Portal hypertension is triggered by vasodilation due to impaired contraction of extrahepatic vessels. Angiotensin II type 1 (AT(1)) receptor-induced vasocontraction is mediated by G proteins and may be desensitized by recruitment of beta-arrestin-2 to the receptor. In this study, we analysed the interaction of AT(1) receptors with beta-arrestin-2 in the context of vascular hypocontractility in rats with CCl(4)-induced cirrhosis.

METHODS

Micronodular liver cirrhosis in rats (n = 15) was induced by regular CCl(4) exposure. Age-matched rats (n = 15) served as controls. Contractility of aortic rings was measured by myography. Protein expressions and phosphorylations were assessed by Western blot analysis, and AT(1) receptor interaction with beta-arrestin-2 by co-immunoprecipitation.

RESULTS

Aortic rings from CCl(4) rats were hypocontractile to angiotensin II independent of nitric oxide synthases (Nomega-nitro-l-arginine methyl ester 200 microM). Expression of the AT(1) receptor, Galpha(q/11) and the contraction-mediating effector Rho kinase was similar in aortas from both groups. Expression and AT(1) receptor binding of beta-arrestin-2 were up-regulated in aortas from CCl(4) rats. Stimulation of isolated aortas with exogenous angiotensin II caused recruitment of beta-arrestin-2 in aortas from noncirrhotic rats, but no further interaction of AT(1) receptors with beta-arrestin-2 was found in aortas from CCl(4) rats. While angiotensin II stimulation resulted in Rho kinase activation in aortas from noncirrhotic rats but not in aortas from CCl(4) rats, extracellular signal-regulated kinase activation in response to angiotensin II was observed in aortas from both groups.

CONCLUSIONS

Vascular hyporesponsiveness to angiotensin II in CCl(4) rats is due to enhanced interaction of the AT(1) receptor with beta-arrestin-2 and consecutively changed receptor function.

Prevalence and distribution of meticillin-resistant Staphylococcus aureus within the environment and staff of a university veterinary clinic

OBJECTIVES

To characterise the distribution of meticillin-resistant Staphylococcus aureus within the environment of a university small animal hospital and compare this with the distribution among staff.

METHODS

Samples were collected from 140 environmental sites and the anterior nares of 64 staff members at the University of Glasgow Small Animal Hospital on a single day (d1). Sixty of the environmental sites were resampled 14 days later (d14).

RESULTS

Meticillin-resistant S aureus was isolated from two of 140 (1.4 per cent; 95 per cent confidence interval: 1.7 to 5.1) environmental sites on d1 and one of 60 (1.7 per cent; 95 per cent confidence interval: 0.4 to 8.9) on d14. Two of the 64 staff sampled were positive for meticillin-resistant S aureus (3.1 per cent; 95 per cent confidence interval: 0.4 to 8.4).

CLINICAL SIGNIFICANCE

A lower prevalence of meticillin-resistant S aureus was observed in the environment than previously reported. The location, relatedness between isolates and the presence of Panton-Valentine leucocidin indicates that the source of the environmental meticillin-resistant S aureus was most likely to have been human rather than animal in these cases. This study presents important information regarding the potential source and distribution of meticillin-resistant S aureus within veterinary hospital environments and highlights potential variability of prevalence of meticillin-resistant S aureus within and between veterinary institutions.

Assessment of subclinical venous catheter-related diseases in horses and associated risk factors

A total of 102 horses that had a catheter introduced intravenously to facilitate treatment had the catheterised jugular vein and contralateral vein examined by ultrasound every 48 hours. Subclinical complications were defined by thrombus formation or thickening of the venous wall, and the data were analysed to establish risk factors for the development of these complications. The horses with a rectal temperature above 38.5 degrees C when the catheter was introduced were four times more likely to develop complications, than the horses with a lower temperature. The administration of a NSAID while the catheter was in place reduced the risk of complications developing.

Sorafenib targets dysregulated Rho kinase expression and portal hypertension in rats with secondary biliary cirrhosis

BACKGROUND AND PURPOSE

Extrahepatic vasodilation and increased intrahepatic vascular resistance represent attractive targets for the medical treatment of portal hypertension in liver cirrhosis. In both dysfunctions, dysregulation of the contraction-mediating Rho kinase plays an important role as it contributes to altered vasoconstrictor responsiveness. However, the mechanisms of vascular Rho kinase dysregulation in cirrhosis are insufficiently understood. They possibly involve mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK)-dependent mechanisms in extrahepatic vessels. As the multikinase inhibitor sorafenib inhibits ERK, we tested the effect of sorafenib on haemodynamics and dysregulated vascular Rho kinase in rats with secondary biliary cirrhosis.

EXPERIMENTAL APPROACH

Secondary biliary cirrhosis was induced by bile duct ligation (BDL). Sorafenib was given orally for 1 week (60 mg.kg(-1).d(-1)). Messenger RNA levels were determined by quantitative real time polymerase chain reaction, protein expressions and protein phosphorylation by Western blot analysis. Aortic contractility was studied by myographic measurements, and intrahepatic vasoregulation by using livers perfused in situ. In vivo, haemodynamic parameters were assessed invasively in combination with coloured microspheres.

KEY RESULTS

In BDL rats, treatment with sorafenib decreased portal pressure, paralleled by decreases in hepatic Rho kinase expression and Rho kinase-mediated intrahepatic vascular resistance. In aortas from BDL rats, sorafenib caused up-regulation of Rho kinase and an improvement of aortic contractility. By contrast, mesenteric Rho kinase remained unaffected by sorafenib.

CONCLUSIONS AND IMPLICATIONS

Intrahepatic dysregulation of vascular Rho kinase expression is controlled by sorafenib-sensitive mechanisms in rats with secondary biliary cirrhosis. Thus, sorafenib reduced portal pressure without affecting systemic blood pressure.