Saliva oxytocin, cortisol, and testosterone levels in adolescent boys with autism spectrum disorder, oppositional defiant disorder/conduct disorder and typically developing individuals.

The aim of the current study was to compare levels of oxytocin, cortisol, and testosterone in adolescents with either autism spectrum disorder (ASD), or oppositional defiant disorder (ODD)/conduct disorder (CD), and in typically developing individuals (TDI), and relate hormone levels to severity and subtype of aggression and callous-unemotional (CU) traits. Saliva concentrations of oxytocin, cortisol, and testosterone were assessed in 114 male participants (N = 49 ASD, N = 37 ODD/CD, N = 28 TDI,) aged 12-19 years (M = 15.4 years, SD = 1.9). The ASD and the ODD/CD groups had significantly lower levels of oxytocin than the TDI group, and the ODD/CD group had significantly higher levels of testosterone than the ASD group. There were no group effects on cortisol levels. Group differences remained for oxytocin after correcting for the influence of CU traits, but were not significant after controlling for aggression. Results for testosterone became non-significant after correction for either CU traits or aggression. Across groups, higher levels of CU traits were related to higher levels of cortisol and testosterone, however, proactive and reactive aggression were unrelated to all three hormonal levels. The current findings show that, regardless of cognitive ability or comorbid disorders, the diagnostic groups (ASD, ODD/CD) differ from each other by their hormonal levels, with the ASD group characterized by relative low level of oxytocin, and the ODD/CD group by a relative low level of oxytocin and high level of testosterone. These group effects were partly driven by differences in CU traits between the groups.

Inhibitory control in BALB/c mice sub-strains during extinction learning.

Dysregulation of executive function (EF) involves alterations in cognitive flexibility / control and is underscored by learning impairments in neurodevelopmental disorders. Here, we examine cognitive inflexibility in BALB/cJ mice (a mouse model showing diminished sociability, increased anxiety and inattentive behaviour) and closely related "reference" BALB/cByJ mice. We used an appetitive extinction paradigm to investigate if cognitive flexibility measures are different between learning acquisition and extinction. The two BALB/c sub-strains learned to respond to a stimulus in a touchscreen operant chamber, after which the reward was removed and responses should be inhibited. Both mice sub-strains showed a different rate of learning while acquiring the task, in which the BALB/cJ mice were faster learners compared to the BALB/cByJ mice. This was not observed during the extinction phase, in which the BALB/cJ mice were able to extinguish responding to unrewarded stimuli equally. Within the BALB/cJ sub-strain, variation in the ability to inhibit a learnt response was observed when comparing them to similar grouped BALB/cByJ mice: BALB/cJ animals that reached the criterion were more reward driven, while BALB/cJ mice failing to reach the set criterion during extinction processing make more mistakes. Additionally, the changes observed during acquisition, were driven by animals not reaching the extinction criterion. Our results suggest that the BALB/c mice sub-strains may use different strategies to learn during appetitive extinction. This may be useful in the phenotypic dissection of cognitive flexibility in BALB/c sub-strains and their mapping on genetic variance revealed by next-generation sequencing in future studies.

Aggression in BALB/cJ mice is differentially predicted by the volumes of anterior and midcingulate cortex.

Anterior cingulate cortex (ACC) and midcingulate cortex (MCC) have been implicated in the regulation of aggressive behaviour. For instance, patients with conduct disorder (CD) show increased levels of aggression accompanied by changes in ACC and MCC volume. However, accounts of ACC/MCC changes in CD patients have been conflicting, likely due to the heterogeneity of the studied populations. Here, we address these discrepancies by studying volumetric changes of ACC/MCC in the BALB/cJ mouse, a model of aggression, compared to an age- and gender-matched control group of BALB/cByJ mice. We quantified aggression in BALB/cJ and BALB/cByJ mice using the resident-intruder test, and related this to volumetric measures of ACC/MCC based on Nissl-stained coronal brain slices of the same animals. We demonstrate that BALB/cJ behave consistently more aggressively (shorter attack latencies, more frequent attacks, anti-social biting) than the control group, while at the same time showing an increased volume of ACC and a decreased volume of MCC. Differences in ACC and MCC volume jointly predicted a high amount of variance in aggressive behaviour, while regression with only one predictor had a poor fit. This suggests that, beyond their individual contributions, the relationship between ACC and MCC plays an important role in regulating aggressive behaviour. Finally, we show the importance of switching from the classical rodent anatomical definition of ACC as cingulate area 2 and 1 to a definition that includes the MCC and is directly homologous to higher mammalian species: clear behaviour-related differences in ACC/MCC anatomy were only observed using the homologous definition.

Emotional face recognition in male adolescents with autism spectrum disorder or disruptive behavior disorder: an eye-tracking study.

Autism Spectrum Disorder (ASD), Oppositional Defiant Disorder (ODD), and Conduct Disorder (CD) are often associated with emotion recognition difficulties. This is the first eye-tracking study to examine emotional face recognition (i.e., gazing behavior) in a direct comparison of male adolescents with Autism Spectrum Disorder or Oppositional Defiant Disorder/Conduct Disorder, and typically developing (TD) individuals. We also investigate the role of psychopathic traits, callous-unemotional (CU) traits, and subtypes of aggressive behavior in emotional face recognition. A total of 122 male adolescents (N = 50 ASD, N = 44 ODD/CD, and N = 28 TD) aged 12-19 years (M = 15.4 years, SD= 1.9) were included in the current study for the eye-tracking experiment. Participants were presented with neutral and emotional faces using a Tobii 1750 eye-tracking monitor to record gaze behavior. Our main dependent eye-tracking variables were: (1) fixation duration to the eyes of a face and (2) time to the first fixation to the eyes. Since distributions of eye-tracking variables were not completely Gaussian, non-parametric tests were chosen to investigate gaze behavior across the diagnostic groups with Autism Spectrum Disorder, Oppositional Defiant Disorder/Conduct Disorder, and Typically Developing individuals. Furthermore, we used Spearman correlations to investigate the links with psychopathy, callous, and unemotional traits and subtypes of aggression as assessed by questionnaires. The relative total fixation duration to the eyes was decreased in both the Autism Spectrum Disorder group and the Oppositional Defiant Disorder/Conduct Disorder group for several emotional expressions. In both the Autism Spectrum Disorder and the Oppositional Defiant Disorder/Conduct Disorder group, increased time to first fixation on the eyes of fearful faces only was nominally significant. The time to first fixation on the eyes was nominally correlated with psychopathic traits and proactive aggression. The current findings do not support strong claims for differential cross-disorder eye-gazing deficits and for a role of shared underlying psychopathic traits, callous-unemotional traits, and aggression subtypes. Our data provide valuable and novel insights into gaze timing distributions when looking at the eyes of a fearful face.

Glutamatergic and GABAergic gene sets in attention-deficit/hyperactivity disorder: association to overlapping traits in ADHD and autism.

Attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorders (ASD) often co-occur. Both are highly heritable; however, it has been difficult to discover genetic risk variants. Glutamate and GABA are main excitatory and inhibitory neurotransmitters in the brain; their balance is essential for proper brain development and functioning. In this study we investigated the role of glutamate and GABA genetics in ADHD severity, autism symptom severity and inhibitory performance, based on gene set analysis, an approach to investigate multiple genetic variants simultaneously. Common variants within glutamatergic and GABAergic genes were investigated using the MAGMA software in an ADHD case-only sample (n=931), in which we assessed ASD symptoms and response inhibition on a Stop task. Gene set analysis for ADHD symptom severity, divided into inattention and hyperactivity/impulsivity symptoms, autism symptom severity and inhibition were performed using principal component regression analyses. Subsequently, gene-wide association analyses were performed. The glutamate gene set showed an association with severity of hyperactivity/impulsivity (P=0.009), which was robust to correcting for genome-wide association levels. The GABA gene set showed nominally significant association with inhibition (P=0.04), but this did not survive correction for multiple comparisons. None of single gene or single variant associations was significant on their own. By analyzing multiple genetic variants within candidate gene sets together, we were able to find genetic associations supporting the involvement of excitatory and inhibitory neurotransmitter systems in ADHD and ASD symptom severity in ADHD.

Practitioner Review: Psychological treatments for children and adolescents with conduct disorder problems - a systematic review and meta-analysis.

BACKGROUND: This meta-analysis evaluates the efficacy of nonpharmacological treatments for conduct disorder (CD) problems in children and adolescents, based on child, parent and teacher report. METHODS: PubMed, PsycINFO and EMBASE were searched for peer-reviewed articles published between January 1970 and March 2015. Main inclusion criteria were nonpharmacological treatment, participants younger than 18 years, clinical CD problems/diagnosis, randomized controlled trials and inclusion of at least one CD problem-related outcome. Treatment efficacy is expressed in effect sizes (ESs) calculated for each rater (parent, teacher, self and blinded observer). RESULTS: Of 1,549 articles retrieved, 17 (published between June 2004 and January 2014) describing 19 interventions met the inclusion criteria. All studies used psychological treatments; only three studies included a blinded observer to rate CD problems. Most studies were of very poor to fair quality. ESs were significant but small for parent-reported outcomes (0.36, 95% CI = 0.27-0.47), teacher-reported outcomes (0.26, 95% CI = 0.12-0.49) and blinded observer outcomes (0.26, 95% CI = 0.06-0.47), and they were nonsignificant for self-reported outcomes (-0.01, 95% CI = -0.25 to 0.23). Comorbidity, gender, age, number of sessions, duration, intervention type, setting, medication use or dropout percentage did not influence the effect of treatment. CONCLUSIONS: Psychological treatments have a small effect in reducing parent-, teacher- and observer-rated CD problems in children and adolescents with clinical CD problems/diagnosis. There is not enough evidence to support one specific psychological treatment over another. Future studies should investigate the influence of participant characteristics (e.g. age of CD onset), use more homogeneous outcome measures and allow better evaluation of study quality. Many reports failed to provide detailed information to allow optimization of psychological treatment strategies.

Elevated microRNA-181c and microRNA-30d levels in the enlarged amygdala of the valproic acid rat model of autism.

Autism spectrum disorders are severe neurodevelopmental disorders, marked by impairments in reciprocal social interaction, delays in early language and communication, and the presence of restrictive, repetitive and stereotyped behaviors. Accumulating evidence suggests that dysfunction of the amygdala may be partially responsible for the impairment of social behavior that is a hallmark feature of ASD. Our studies suggest that a valproic acid (VPA) rat model of ASD exhibits an enlargement of the amygdala as compared to controls rats, similar to that observed in adolescent ASD individuals. Since recent research suggests that altered neuronal development and morphology, as seen in ASD, may result from a common post-transcriptional process that is under tight regulation by microRNAs (miRs), we examined genome-wide transcriptomics expression in the amygdala of rats prenatally exposed to VPA, and detected elevated miR-181c and miR-30d expression levels as well as dysregulated expression of their cognate mRNA targets encoding proteins involved in neuronal system development. Furthermore, selective suppression of miR-181c function attenuates neurite outgrowth and branching, and results in reduced synaptic density in primary amygdalar neurons in vitro. Collectively, these results implicate the small non-coding miR-181c in neuronal morphology, and provide a framework of understanding how dysregulation of a neurodevelopmentally relevant miR in the amygdala may contribute to the pathophysiology of ASD.

Evidence for a role of 5-HT2C receptors in the motor aspects of performance, but not the efficacy of food reinforcers, in a progressive ratio schedule.

RATIONALE: 5-Hydroxytryptamine2C (5-HT2C) receptor agonists reduce the breakpoint in progressive ratio schedules of reinforcement, an effect that has been attributed to a decrease of the efficacy of positive reinforcers. However, a reduction of the breakpoint may also reflect motor impairment. Mathematical models can help to differentiate between these processes. OBJECTIVE: The effects of the 5-HT2C receptor agonist Ro-600175 ((αS)-6-chloro-5-fluoro-α-methyl-1H-indole-1-ethanamine) and the non-selective 5-HT receptor agonist 1-(m-chlorophenyl)piperazine (mCPP) on rats' performance on a progressive ratio schedule maintained by food pellet reinforcers were assessed using a model derived from Killeen's Behav Brain Sci 17:105-172, 1994 general theory of schedule-controlled behaviour, 'mathematical principles of reinforcement'. METHOD: Rats were trained under the progressive ratio schedule, and running and overall response rates in successive ratios were analysed using the model. The effects of the agonists on estimates of the model's parameters, and the sensitivity of these effects to selective antagonists, were examined. RESULTS: Ro-600175 and mCPP reduced the breakpoint. Neither agonist significantly affected a (the parameter expressing incentive value), but both agonists increased δ (the parameter expressing minimum response time). The effects of both agonists could be attenuated by the selective 5-HT2C receptor antagonist SB-242084 (6-chloro-5-methyl-N-{6-[(2-methylpyridin-3-yl)oxy]pyridin-3-yl}indoline-1-carboxamide). The effect of mCPP was not altered by isamoltane, a selective 5-HT1B receptor antagonist, or MDL-100907 ((±)2,3-dimethoxyphenyl-1-(2-(4-piperidine)methanol)), a selective 5-HT2A receptor antagonist. CONCLUSIONS: The results are consistent with the hypothesis that the effect of the 5-HT2C receptor agonists on progressive ratio schedule performance is mediated by an impairment of motor capacity rather than by a reduction of the incentive value of the food reinforcer.

AKAPs integrate genetic findings for autism spectrum disorders.

Autism spectrum disorders (ASDs) are highly heritable, and six genome-wide association studies (GWASs) of ASDs have been published to date. In this study, we have integrated the findings from these GWASs with other genetic data to identify enriched genetic networks that are associated with ASDs. We conducted bioinformatics and systematic literature analyses of 200 top-ranked ASD candidate genes from five published GWASs. The sixth GWAS was used for replication and validation of our findings. Further corroborating evidence was obtained through rare genetic variant studies, that is, exome sequencing and copy number variation (CNV) studies, and/or other genetic evidence, including candidate gene association, microRNA and gene expression, gene function and genetic animal studies. We found three signaling networks regulating steroidogenesis, neurite outgrowth and (glutamatergic) synaptic function to be enriched in the data. Most genes from the five GWASs were also implicated--independent of gene size--in ASDs by at least one other line of genomic evidence. Importantly, A-kinase anchor proteins (AKAPs) functionally integrate signaling cascades within and between these networks. The three identified protein networks provide an important contribution to increasing our understanding of the molecular basis of ASDs. In addition, our results point towards the AKAPs as promising targets for developing novel ASD treatments.

Effects of d-amphetamine and DOI (2,5-dimethoxy-4-iodoamphetamine) on timing behavior: interaction between D1 and 5-HT2A receptors.

RATIONALE: The dopamine-releasing agent d-amphetamine and the 5-HT(2) receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI) have similar effects on free-operant timing behavior. The selective D(1) dopamine receptor antagonist 8-bromo-2,3,4,5-tetrahydro-3-methyl-5-phenyl-1H-3-benzazepin-7-ol (SKF-83566), but not the D(2) dopamine receptor antagonist haloperidol, can antagonize the effect of d-amphetamine, and the selective 5-HT(2A) receptor antagonist (+/-)2,3-dimethoxyphenyl-1-(2-(4-piperidine)-methanol (MDL-100907) can antagonize the effect of DOI. However, it is not known whether the effect of d-amphetamine can be reversed by MDL-100907 and the effect of DOI by dopamine receptor antagonists. OBJECTIVE: The objective of this work is to examine the interactions of d-amphetamine and DOI with MDL-100907, SKF-83566, and haloperidol on timing performance. MATERIALS AND METHODS: Rats (n = 12-15 per experiment) were trained under the free-operant psychophysical procedure to press two levers (A and B) in 50-s trials in which reinforcement was provided intermittently for responding on A in the first half, and B in the second half of the trial. Percent responding on B (%B) was recorded in successive 5-s epochs of the trials; logistic functions were fitted to the data from each rat for the derivation of timing indices [T (50) (time corresponding to %B = 50); Weber fraction]. Rats were treated systemically with d-amphetamine or DOI, alone and in combination with haloperidol, SKF-83566, or MDL-100907. RESULTS: d-Amphetamine (0.4 mg kg(-1)) reduced T (50) compared to vehicle; this effect was antagonized by SKF-83566 (0.03 mg kg(-1)) and MDL-100907 (0.5 mg kg(-1)), but not by haloperidol (0.05, 0.1 mg kg(-1)). DOI (0.25 mg kg(-1)) also reduced T (50); this effect was reversed by MDL-100907 (0.5 mg kg(-1)), but not by SKF-83566 (0.03 mg kg(-1)) or haloperidol (0.05 mg kg(-1)). CONCLUSIONS: The results suggest that both 5-HT(2A) and D(1) receptors, but not D(2) receptors, are involved in d-amphetamine's effect on timing behavior in the free-operant psychophysical procedure. DOI's effect on timing is mediated by 5-HT(2A) receptors, but neither D(1) nor D(2) receptors are involved in this effect.

Dopamine receptor pharmacology: interactions with serotonin receptors and significance for the aetiology and treatment of schizophrenia.

The classification of dopamine receptors proposed more than two decades ago remains valid today. Based on biochemical and pharmaceutical properties two main classes of dopamine receptors can be distinguished: D(1)-like (D(1), D(5)) and D(2)-like (D(2), D(3), and D(4)) dopamine receptors. Dopamine receptors belong to the class of G protein-coupled receptors and signal to a wide range of membrane bound and intracellular effectors such as ion channels, secondary messenger systems and enzymes. Although the pharmacological properties of ligands for D(1)-like and D(2)-like dopamine receptors are quite different, the number of selective ligands for each of the five receptors subtypes is rather small. Many drugs used to treat neurological and neuropsychiatric disorders like Parkinson's disease, restless leg syndrome and schizophrenia have affinities for dopamine receptors. Such medications are not without limitations so the development of novel (selective or aselective) dopamine receptor ligands is of the utmost importance for improved therapeutic approaches for these diseases. In that respect it is also important to understand how dopamine receptor ligands affect receptor signalling processes such as desensitization, receptor heterodimerization and agonist-receptor trafficking, issues which will be discussed in the present review. Furthermore, attention is paid to interactions of dopamine receptors with serotonin receptors since many drugs used to treat above mentioned disorders of the brain also possess affinities for serotonin receptors. Because of the enormity of this area we have tried to focus more specifically on interactions within the prefrontal cortex where it appears that the serotonergic modulation of dopaminergic function might be very relevant to schizophrenia.

Evidence that the effect of 5-HT2 receptor stimulation on temporal differentiation is not mediated by receptors in the dorsal striatum.

5-HT2 receptor stimulation alters temporal differentiation in free-operant timing schedules. The anatomical location of the receptor population responsible for this effect is unknown. We examined the effect of a 5-HT2 receptor agonist and antagonists, injected systemically and into the dorsal striatum, a region that is believed to play a major role in interval timing. Rats were trained under the free-operant psychophysical procedure to press levers A and B in 50s trials in which reinforcement was provided intermittently for responding on A in the first half, and B in the second half of the trial. Percent responding on B (%B) was recorded in successive 5s epochs of the trials; logistic functions were fitted to the data from each rat to derive timing indices (T50: time corresponding to %B = 50; Weber fraction: [T75-T25]/2T50, where T75 and T25 are the times corresponding to %B = 75 and %B = 25). Systemic treatment with the 5-HT(2A/2C) receptor agonist 2,5,-dimethoxy-4-iodo-amphetamine (DOI) (0.25 mg/kg, s.c.) reduced T50; the 5-HT2A receptor antagonist MDL-100907 (0.5 mg/kg, i.p.) did not affect performance, but completely blocked the effect of DOI. DOI (1 and 3 microg) injected bilaterally into the dorsal striatum did not alter T50. The effect of systemic treatment with DOI (0.25 mg/kg, s.c.) was not altered by intra-striatal injection of MDL-100907 (0.3 microg) or the 5-HT2C receptor antagonist RS-102221 (0.15 microg). The ability of systemically administered MDL-100907 to reverse DOI's effect on T50 confirms the sensitivity of temporal differentiation to 5-HT2A receptor stimulation. The failure of intra-striatal MDL-100907 to antagonize the effects of DOI suggests that 5-HT2A receptors in the dorsal striatum are unlikely to be primarily responsible for DOI's effects on timing. Furthermore, the results provide no evidence for a role of striatal 5-HT2C receptors in DOI's effect on timing.

Nigral neurotensin receptor regulation of nigral glutamate and nigroventral thalamic GABA transmission: a dual-probe microdialysis study in intact conscious rat brain.

Dual-probe microdialysis in the awake rat was employed to investigate the effects of intranigral perfusion with the tridecapeptide neurotensin on local dialysate glutamate and GABA levels in the substantia nigra pars reticulata and on dialysate GABA levels in the ventral thalamus. Intranigral neurotensin (10-300nM, 60min) dose-dependently increased (+29+/-3% and +46+/-3% vs basal for the 100 and 300nM concentrations, respectively) local dialysate glutamate levels, while the highest 300nM concentration of the peptide exerted a long-lasting and prolonged reduction in both local and ventral thalamic (-20+/-4% and -22+/-2%, respectively) GABA levels. Intranigral perfusion with the inactive neurotensin fragment neurotensin(1-7) (10-300nM, 60min) was without effect. Furthermore, the non-peptide neurotensin receptor antagonist SR 48692 (0.2mg/kg) and tetrodotoxin (1microM) fully counteracted the intranigral neurotensin (300nM)-induced increase in local glutamate. SR 48692 (0.2mg/kg) also counteracted the decreases in nigral and ventral thalamic GABA release induced by the peptide. In addition, intranigral perfusion with the dopamine D(2) receptor antagonist raclopride (1microM) fully antagonized the neurotensin (300nM)-induced decreases in nigral and ventral thalamic GABA levels. The ability of nigral neurotensin receptor activation to differently influence glutamate and GABA levels, whereby it increases nigral glutamate and decreases both nigral and ventral thalamic GABA levels, suggests the involvement of neurotensin receptor in the regulation of basal ganglia output at the level of the nigra.

Differential effects of acute and short-term lithium administration on dialysate glutamate and GABA levels in the frontal cortex of the conscious rat.

In the present study, we employed in vivo microdialysis in the frontal cortex of the awake rat to investigate the effects of acute and short-term (twice daily, 3 days) lithium chloride administration (1, 2, and 4 meq/kg, s.c.) on local dialysate glutamate and GABA levels. Acute lithium (1 meq/kg) failed to influence cortical glutamate levels while the higher (2 and 4 meq/kg) doses increased (+38 +/- 6% of basal levels) and reduced (-27 +/- 4%) cortical glutamate levels, respectively. Cortical GABA levels were affected by acute lithium only at the highest 4 meq/kg dose (+62 +/- 6%). Furthermore, these effects were prevented by tetrodotoxin (1 microM) and low-calcium (0.2 mM) medium perfusion. Following short-term administration, lithium increased (+58 +/- 4%) cortical dialysate glutamate levels at the 1 meq/kg dose, was ineffective at 2 meq/kg, while the effect of the 4 meq/kg dose was similar to that observed after acute administration. Interestingly, intracortical perfusion with the GABA(B) receptor antagonist CGP 35348 (100 microM) reversed the acute lithium (4 meq/kg)-induced decrease in glutamate levels. Taken together, these findings indicate a differential dose and duration dependent effect of lithium on cortical dialysate glutamate levels involving both a direct enhancement and an indirect inhibition that is mediated via an activation of local GABA(B) receptor. These findings may be relevant for the therapeutic effects of the drug.

The effect of long-term bone plate application for fixation of radial fractures in dogs.

This study was divided into two phases. In the in vitro phase, a stainless steel bone plate was applied to the cranial surface of the radius in 14 canine limbs. The effect of the presence of a bone plate on bone density analysis using radiographic photodensitometry (RP) was evaluated by comparing the density measurement of the unplated limb to the density measurement of the plated limb. The optical density of the plated bones was 12% greater than that of the unplated bones. This information was used as a correction factor for the in vivo study. In the in vivo phase, 23 dogs with radial and ulnar fractures were examined for complications associated with the long-term application of a stainless steel plate applied to the cranial surface of the radius. In 14 dogs, RP analysis was used to compare the plated limb with the normal, contralateral limb. No significant differences in radial cortical bone density existed between the plated limb and the contralateral limb after taking into account the effect a bone plate had on photodensitometry readings. There was no significant correlation between the change in radial cortical density and the duration of bone plate application, suggesting that a steady state between bone loss and bone production occurs after long-term plate fixation of the fractured canine radius. The majority (87%) of the dogs with a plate applied to the radius greater than 1 year had normal limb usage when standing, walking, or running.

Decreased incidence of postoperative urinary incontinence with a modified Penrose drain technique for treatment of prostatic abscesses in dogs.

Drainage with multiple Penrose drains is currently recommended as the primary treatment for canine prostatic abscesses. A recent report indicated that short term and long term urinary incontinence is a frequent complication associated with this technique. In this study, a modified multiple Penrose drain technique that avoids dissection dorsal to the prostate gland was performed in 17 dogs. Long term follow up information was obtained by telephone interview with the owners. Three dogs had urinary incontinence that resolved spontaneously within 3 days of surgery. Within the first year after that period, no other dogs developed incontinence. An excellent result was recorded in 12 dogs (71%) and a good result in 5 dogs (29%) having prostatic abscess drainage.

Surgical correction of an intestinal obstruction in a turtle.

Ingested scutes caused an intestinal obstruction in an 18-year-old turtle. An enterotomy, performed through a flank approach to the celiac cavity, successfully relieved the obstruction. The scutes were ingested during a period of neglect by the owner.

Antihypertensive and orthostatic responses to drugs in conscious dogs.

In view of the frequent occurrence of orthostatic hypotension in antihypertensive therapy, the orthostatic potential of various classes of drugs was evaluated in conscious normotensive dogs in order to assess the utility of this model. Antihypertensive effectiveness was ascertained initially in hypertensive dogs. Inhibitors of peripheral sympathetic vasoconstrictor mechanism (phentolamine, prazosin, guanethidine) produced marked orthostatic hypotension at antihypertensive doses. In contrast, clonidine did not. The vasodilator hydralazine and, to some extent, minoxidil also caused postural effects. It is concluded that conscious dogs are useful in assessing the orthostatic potential of antihypertensive drugs but that their predictability to humans is not universal.

Captopril, alone and in combination with hydrochlorothiazide, on responses to upright tilt in conscious dogs.

Orthostatic hypotension occurs relatively frequently in antihypertensive therapy. Although vasodilators are usually not associated with this response, hydralazine and to some extent minoxidil produced marked orthostasis in conscious dogs in a prior series of experiments. Captopril also reduces blood pressure by a peripheral mechanism. Therefore, its influence on responses to upright tilt were evaluated. Oral administration of captopril reduced blood pressure of conscious normotensive dogs. Even greater falls occurred after pretreatment with hydrochlorothiazide. However, the increases in blood pressure and heart rate observed during upright tilting were not altered by captopril.