Dynamic Coronary Roadmap versus standard angiography for percutaneous coronary intervention: the randomised, multicentre DCR4Contrast trial

BACKGROUND

Decreasing the amount of iodinated contrast is an important safety aspect of percutaneous coronary interventions (PCI), particularly in patients with a high risk of contrast-induced acute kidney injury (CI-AKI). Dynamic Coronary Roadmap (DCR) is a PCI navigation support tool projecting a motion-compensated virtual coronary roadmap overlay on fluoroscopy, potentially limiting the need for contrast during PCI.

AIMS

This study investigates the contrast-sparing potential of DCR in PCI, compared to standard angiographic guidance.

METHODS

The Dynamic Coronary Roadmap for Contrast Reduction (DCR4Contrast) trial is a multicentre, international, prospective, unblinded, stratified 1:1 randomised controlled trial. Patients were randomised to either DCR-guided PCI or to conventional angiography-guided PCI. The primary endpoint was the total volume of iodinated contrast administered, and the secondary endpoint was the number of cineangiography runs during PCI.

RESULTS

The study population included 356 randomised patients (179 in DCR and 177 in control groups, respectively). There were no differences in patient demographics, angiographic characteristics or estimated glomerular filtration rate (eGFR) between the two groups. The total contrast volume used during PCI was significantly lower with DCR guidance compared with conventional angiographic guidance (64.6±44.4 ml vs 90.8±55.4 ml, respectively; p<0.001). The total number of cineangiography runs was also significantly reduced in the DCR group (8.7±4.7 vs 11.7±7.6 in the control group; p<0.001).

CONCLUSIONS

Compared to conventional angiography-guided PCI, DCR guidance was associated with a significant reduction in both contrast volume and the number of cineangiography runs during PCI. (ClinicalTrials.gov: NCT04085614).

Treatment of Severe Left Ventricular Outflow Tract Obstruction and Mitral Regurgitation With Alcohol Septal Ablation

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Hypertrophic cardiomyopathy is a common genetic heart disease.

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Patients can have variable clinical manifestations and severity of disease.

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Manifestations include LVOT obstruction and MR.

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Alcohol septal ablation can successfully treat LVOT obstruction and MR.

Outcomes of Stented vs Nonstented Femoropopliteal Lesions Treated With Drug-Coated Balloon Angioplasty

PURPOSE

Drug-coated balloon (DCB) angioplasty has been increasingly used for the treatment of lower limb peripheral artery disease (PAD). However, bail-out stenting may be necessary in cases of suboptimal angioplasty. This study investigated the outcomes of femoropopliteal disease treated with DCB with/without bail-out stenting.

MATERIALS AND METHODS

This was a single-center retrospective study enrolling 166 consecutive patients (DCB+stent: n=81 vs DCB: n=85) with 253 femoropopliteal lesions (DCB+stent: n=99 vs DCB: n=154) treated with DCB with/without stenting. Bail-out stenting was performed at the operator discretion for postangioplasty dissections or otherwise suboptimal angiographic result (>30% residual stenosis). Cox regression analysis was performed to examine the outcomes of DCB with/without stenting during 2-year follow-up.

RESULTS

The baseline clinical characteristics were similar between the 2 groups. About half of the patients presented with critical limb ischemia, with most of the lesions located at the superficial femoral artery. The overall mean lesion length was 147±67 mm. The most frequent bail-out stent types were bare metal stents (BMS) (53.5%) followed by drug-eluting stents (DES) (41.4%). Lesions requiring bail-out stenting were on average longer (177±67 mm vs 127±59 mm; p<0.01) and on average had higher prevalence of flow-limiting postangioplasty dissections. The overall procedural success rate was 94% without any differences between the 2 groups. Both the stented and nonstented treatment modalities were effective and safe, demonstrating similar rates of 2-year freedom from major adverse limb event (stented: 71.3% vs nonstented: 64.4%) and 2-year freedom from target lesion revascularization (stented: 77.1% vs nonstented: 72.3%) during following up. The use of DES as bail-out therapy was associated with a lower risk of 2-year death compared with the use of BMS (DES: 97.2% vs BMS: 75.8%; p=0.01).

CONCLUSION

Drug-coated balloon with bail-out stenting is a viable treatment option for cases of suboptimal DCB results, promising similar efficacy with DCB-alone procedures. However, as the patency of stents at the femoropopliteal segment may be a challenge due to the biomechanical stress of the artery, the efficacy of DCB+bail-out stenting should be further evaluated. In addition, future studies are needed to determine which grades of post-DCB dissections should be treated and optimize current bail-out strategies.

Clinical Characteristics and Outcomes Among Patients Undergoing High-Risk Percutaneous Coronary Interventions by Single or Multiple Operators: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

Background High-risk percutaneous coronary intervention (HR-PCI) is increasingly common among contemporary patients with coronary artery disease. Experts have advocated for a collaborative 2-operator approach to support intraprocedural decision-making for these complex interventions. The impact of a second operator on patient and procedural outcomes is unknown. Methods and Results Patients who underwent HR-PCI from 2015 to 2018 within the Veterans Affairs Healthcare System were identified. Propensity-matched cohorts were generated to compare the outcomes following HR-PCI performed by a single or multiple (≥2) operators. The primary end point was the 12-month rate of major adverse cardiovascular events. We identified 6672 patients who underwent HR-PCI during the study period; 6211 (93%) were treated by a single operator, and 461 (7%) were treated by multiple operators, with a nonsignificant trend toward increased multioperator procedures over time. A higher proportion of patients treated by multiple operators underwent left main (10% versus 7%, P=0.045) or chronic total occlusion intervention (11% versus 5%, P<0.001). Lead interventionalists participating in multioperator procedures practiced at centers with higher annual HR-PCI volumes (124±71.3 versus 111±69.2; standardized mean difference, 0.197; P<0.001) but otherwise performed a similar number of HR-PCI procedures per year (34.4±35.3 versus 34.7±30.7; standardized mean difference, 0.388; P=0.841) compared with their peers performing single-operator interventions. In a propensity-matched cohort, there was no significant difference in major adverse cardiovascular events (32% versus 30%, P=0.444) between patients who underwent single-operator versus multioperator HR-PCI. Adjusted analyses accounting for site-level variance showed no significant differences in outcomes. Conclusions Patients who underwent multioperator HR-PCI had similar outcomes compared with single-operator procedures. Further studies are needed to determine if the addition of a second operator offers clinical benefits to a subset of HR-PCI patients undergoing left main or chronic total occlusion intervention.

How the COVID-19 Pandemic Has Affected Cardiology Fellow Training

With the advent of the COVID-19 pandemic in the United States, resources have been reallocated and elective cases have been deferred to minimize the spread of the disease, altering the workflow of cardiac catheterization laboratories across the country. This has in turn affected the training experience of cardiology fellows, including diminished procedure numbers and a narrow breadth of cases as they approach the end of their training before joining independent practice. It has also taken a toll on the emotional well-being of fellows as they see their colleagues, loved ones, patients or even themselves struggling with COVID-19, with some succumbing to it. The aim of this opinion piece is to focus attention on the impact of the COVID-19 pandemic on fellows and their training, challenges faced as they transition to practicing in the real world in the near future and share the lessons learned thus far. We believe that this is an important contribution and would be of interest not only to cardiology fellows-in-training and cardiologists but also trainees in other procedural specialties.

Association of Postangioplasty Femoropopliteal Dissections With Outcomes After Drug-Coated Balloon Angioplasty in the Femoropopliteal Arteries

PURPOSE

Balloon angioplasty for the treatment of femoropopliteal lesions is often complicated by postangioplasty dissections. While dissections are known to affect patency and reintervention after balloon angioplasty, the association between dissections and major adverse limb event (MALE) after drug-coated balloon (DCB) angioplasty remains uncertain. Thus, the postangioplasty dissection and bailout stenting patterns were investigated.

MATERIALS AND METHODS

This was a single-center retrospective study enrolling patients with de novo femoropopliteal lesions treated with DCB with/without stenting. Postangioplasty target vessel dissection was graded based to the coronary artery classification grades A-F, with grade C-F considered "severe." Cox regression analysis was performed to examine the association of dissection severity with outcomes during 2-year follow up, among nonstented cases.

RESULTS

In 85.3% of the cases (N=203/238) a postangioplasty dissection was observed. The average dissection length was 55.57 mm (SD 36.71 mm), with 1 dissection present in 91.8% (N=180/196) and 2 or more dissections present in 8.2% (N=16/196). Dissection severity was grade A (19.8%), B (20.6%), C (23.1%), D (10.9%), E (10.1%), and F (0.8%). Bailout stenting was required in 40.4% of the patients, being more prevalent among grade C and grade E cases. Among 142 nonstented cases, dissections were present in 85.2%. A total of 75 (52.8%) of these dissections were grade A and B, while 46 (32.4%) were grade C to F. Among nonstented cases, grade C (hazard ratio [HR] 5.83; 95% CI 1.25 to 27.31; p=0.025) and grade D (HR 6.32; 95% CI 1.39 to 28.86; p=0.017) vs grade A dissections were associated with a higher risk for 2-year MALE. Multivariate analysis adjusting for several lesion characteristics demonstrated a statistically significant higher risk for 2-year MALE among the severe dissection group (HR 2.94; 95% CI 1.27 to 6.79; p = 0.012). Interestingly, the risks of limb loss (HR 1.30; 95% CI 0.22 to 7.79; p=0.774) and repeat revascularization (HR 0.95; 95% CI 0.40 to 2.26; p=0.905) during follow-up were similar between the 2 groups.

CONCLUSION

This study indicated that nonstented moderate and severe postangioplasty dissections after DCB angioplasty were associated with higher risk for MALE. Future studies are needed to validate our results and determine other dissection characteristics (eg, total dissection length, lumen area, total number of dissections) that may affect the efficacy of DCB.

Dimensional anxiety scales for DSM-5: sensitivity to clinical severity

PURPOSE

Psychometric properties and clinical sensitivity of brief self-rated dimensional scales to supplement categorical diagnoses of anxiety disorders in the DSM-5 were recently demonstrated in a German treatment seeking sample of adults. The present study aims to demonstrate sensitivity of these scales to clinical severity levels.

METHODS

The dimensional scales were administered to 102 adults at a university outpatient clinic for psychotherapy. Diagnostic status was assessed using the Munich-Composite International Diagnostic Interview. To establish a wide range of clinical severity, we considered subthreshold (n=83) and threshold anxiety disorders (n=49, including Social Phobia, Specific Phobia, Agoraphobia, Panic Disorder, and Generalized Anxiety Disorder).

RESULTS

Individuals with either subthreshold or threshold anxiety disorder scored higher on all dimensional scales relative to individuals without anxiety. In addition, individuals with a threshold anxiety disorder scored higher on the dimensional scales than individuals with a subthreshold anxiety disorder (except for specific phobia). Disorder-related impairment ratings, global functioning assessments and number of panic attacks were associated with higher scores on dimensional scales. Findings were largely unaffected by the number of anxiety disorders and comorbid depressive disorders.

CONCLUSION

The self-rated dimensional anxiety scales demonstrated sensitivity to clinical severity, and a cut-off based on additional assessment of impairment and distress may assist in the discrimination between subthreshold and threshold anxiety disorders. Findings suggest further research in various populations to test the utility of the scales for use in DSM-5.

A functional dopamine-beta-hydroxylase gene promoter polymorphism is associated with impulsive personality styles, but not with affective disorders

Dopamine-beta-hydroxylase (DbetaH) catalyzes the conversion of dopamine to norepinephrine in central noradrenergic and adrenergic neurons and thus is critically involved in the biosynthesis of catecholamines. There are equivocal findings concerning the question whether or not DssH activity levels are altered in affective disorders or in subtypes of affective disorders. Moreover, information about the role of dopamine beta-hydroxylase (DBH) genotype, which explains a large part of the variance of enzymatic activity, in affective disorders and personality dimensions is limited. To resolve these inconsistencies, association tests were performed using four independent samples, healthy volunteers (N = 387), patients with affective disorders (N = 182), adult attention deficit hyperactivity disorder (ADHD) patients (N = 407), and patients with personality disorders (N = 637). In the latter two samples, the revised NEO personality inventory (NEO-PI-R) was administered. All participants were genotyped for a putatively functional single nucleotide polymorphism (C-1021T, rs1611115). No differences in DBH C-1021T genotype distribution were observed between patients with affective disorders and healthy control subjects. Also when the patient sample was divided into uni- and bipolar patients versus controls, no significant differences emerged. Furthermore, no clear-cut association was detected between the TT genotype and personality disorder clusters while there was a significant association with adult ADHD. However, personality disorder patients carrying the DBH TT genotype exhibited higher neuroticism and novelty seeking scores as compared to individuals with the CC or CT genotype. Analyses on the level of the neuroticism and novelty seeking subscales revealed that the DBH TT genotype was primarily associated with personality features related to impulsiveness and aggressive hostility. Also adult ADHD patients carrying the homozygous TT genotypes displayed by significantly increased neuroticism scores; when both personality disorder and adult ADHD patient were analyzed together, TT carriers also displayed by significantly lower conscientiousness levels. Our results thus do not implicate the DBH C-1021T polymorphism in the pathophysiology of depressive disorders or personality disorders, yet homozygosity at this locus appears to increase the risk towards personality traits related to impulsiveness, aggression and related disease states, namely adult ADHD. These data argue for a dimensional rather than categorical effect of genetic variance in DBH activity; accordingly, the inconsistency of previous findings concerning DbetaH levels in affective disorders might be caused by the underlying association of the TT genotype at DBH-1021 with impulsive personality traits.

NO synthase-positive striatal interneurons are decreased in schizophrenia

The gaseous messenger NO has repeatedly been suggested to play a role in the pathogenesis of psychoses. Following a pilot study, we investigated whether the number of nitrinergic neurons in the putamen of patients suffering from schizophrenia, bipolar disorder or major depression is altered. Post-mortem striatum sections of 15 brains from patients with either disease were examined by NADPH-diaphorase staining, which selectively labels NO synthase-positive interneurons. Quantification of these cells revealed significantly lower numbers of NO synthase-containing neurons in the putamen of schizophrenic patients. Our results suggest that striatal nitrinergic interneurons are involved in the pathophysiology of at least some forms of schizophrenia, such as e.g. catatonic schizophrenia.

[Retained foreign bodies from the surgical point of view]

The number of foreign bodies remaining in the patient after a surgical procedure is presumably higher than mentioned in the literature. According to US insurance statistics, the incidence amounts to 1 in 1,500 surgical procedures. As a basic principle--also from the legal aspect--it is necessary to determine whether a foreign body was left in situ accidentally (i.e. due to a material fault) or if it was simply forgotten. In 70% of cases, fabric items (e.g. swabs etc.) are left behind, while around 30% are metal objects. A particularly high risk is seen in emergency settings, in unexpected changes in the surgical procedure, or for patients with a high body mass index. The outcome for the patient differs depending on the nature of the object left behind and the individual patient's situation. Usually, metal items cause more acute clinical symptoms at an earlier time after the operation. Fabric items tend to induce, in the absence of primary contamination, a chronic progression of symptoms over several years. Reoperation has a high mortality (between 11% and 35%). Precautions in terms of risk management have to be established and need to be strictly respected, especially in high risk settings. Visually or acoustically controlled monitoring before wound-closure are recommended to eliminate "human error" as thoroughly as possible.

FZD3 is not a risk gene for schizophrenia: a case-control study in a Caucasian sample

BACKGROUND

Polymorphisms in the human frizzeled-3 (FZD3) gene have been associated with schizophrenia in an Asian population sample. However, this finding could not be confirmed in subsequent studies investigating other populations. Here we attempted to replicate this finding in a sample of 192 German chronically ill schizophrenic subjects.

METHODS

Three single nucleotide polymorphisms in the FZD3 gene have been genotyped by primer extension and MALDI-TOF measurement. Subsequently, associations for single markers as well as haplotypes were tested.

RESULTS

In German patients, neither single markers nor haplotypes in FZD3 were associated with schizophrenia. Further exploratory analyses using a different diagnostic approach did also not yield significant results.

CONCLUSIONS

FZD3 is unlikely to play a role in the genetic predisposition towards schizophrenia in the Caucasian population.

Serotonin transporter gene variation impacts innate fear processing: Acoustic startle response and emotional startle

Anxiety-related behaviors are closely linked to neural circuits relaying fear-specific information to the amygdala. Many of these circuits, like those underlying processing of innate fear, are remarkably well understood. Recent imaging studies have contributed to this knowledge by discriminating more detailed corticoamygdalar associations mediating processing fear and anxiety. However, little is known about the underlying molecular mechanisms. We used the acoustic startle paradigm to investigate the impact of molecular genetic variation of serotonergic function on the acoustic startle response and its fear potentiation. Startle magnitudes to noise bursts as measured with the eye blink response were recorded in 66 healthy volunteers under four conditions: presenting unpleasant and pleasant affective pictures as well as neutral pictures, and presenting the startle stimulus without additional stimuli as a baseline. Subjects were genotyped for functional polymorphism in the transcriptional control region of the serotonin transporter gene (5-hydroxytryptamine transporter gene-linked region: 5-HTTLPR). Analyses of variance revealed a significant effect of 5-HTTLPR on overall startle responses across conditions. Carriers of the short (s) allele exhibited stronger startle responses than l/l homozygotes. However, we could not confirm our hypothesis of enhanced fear potentiation of the startle in s allele carriers. In conclusion, the results provide first evidence that the startle response is sensitive to genetic variation in the serotonin pathway. Despite some issues remaining to be resolved, the startle paradigm may provide a valuable endophenotype of fear processing and underlying serotonergic influences.

Neural stem cell proliferation is decreased in schizophrenia, but not in depression

The phenomenon of adult neurogenesis (AN), that is, the generation of functional neurons from neural stem cells in the dentate gyrus of the hippocampus, has attracted remarkable attention, especially as it was shown that this process is also active in the human brain. Based on animal studies, it has been suggested that reduced AN is implicated in the etiopathology of psychiatric disorders, and that stimulation of AN contributes to the mechanism of action of antidepressant therapies. As data from human post-mortem brain are still lacking, we investigated whether the first step of AN, that is, the level of neural stem cell proliferation (NSP; as quantified by Ki-67 immunohistochemistry), is altered in tissue from the Stanley Foundation Neuropathology Consortium comprising brain specimens from patients with bipolar affective disorder, major depression, schizophrenia as well as control subjects (n=15 in each group). The hypothesis was that stem cell proliferation is reduced in affective disorders, and that antidepressant treatment increases NSP. Neither age, brain weight or pH, brain hemisphere investigated nor duration of storage had an effect on NSP. Only in bipolar disorder, post-mortem interval was a significant intervening variable. In disease, onset of the disorder and its duration likewise did not affect NSP. Also, cumulative lifetime dose of fluphenazine was not correlated with NSP, and presence of antidepressant treatment did not result in an increase of NSP. Concerning the different diagnostic entities, reduced amounts of newly formed cells were found in schizophrenia, but not in major depression. Our findings suggest that reduced NSP may contribute to the pathogenesis of schizophrenia, whereas the rate of NSP does not seem to be critical to the etiopathology of affective disorders, nor is it modified by antidepressant drug treatment.

A neuronal nitric oxide synthase (NOS-I) haplotype associated with schizophrenia modifies prefrontal cortex function

Nitric oxide (NO) is a gaseous neurotransmitter thought to play important roles in several behavioral domains. On a neurobiological level, NO acts as the second messenger of the N-methyl-D-aspartate receptor and interacts with both the dopaminergic as well as the serotonergic system. Thus, NO is a promising candidate molecule in the pathogenesis of endogenous psychoses and a potential target in their treatment. Furthermore, the chromosomal locus of the gene for the NO-producing enzyme NOS-I, 12q24.2, represents a major linkage hot spot for schizophrenic and bipolar disorder. To investigate whether the gene encoding NOS-I (NOS1) conveys to the genetic risk for those diseases, five NOS1 polymorphisms as well as a NOS1 mini-haplotype, consisting of two functional polymorphisms located in the transcriptional control region of NOS1, were examined in 195 chronic schizophrenic, 72 bipolar-I patients and 286 controls. Single-marker association analysis showed that the exon 1c promoter polymorphism was linked to schizophrenia (SCZ), whereas synonymous coding region polymorphisms were not associated with disease. Long promoter alleles of the repeat polymorphism were associated with less severe psychopathology. Analysis of the mini-haplotype also revealed a significant association with SCZ. Mutational screening did not detect novel exonic polymorphisms in patients, suggesting that regulatory rather than coding variants convey the genetic risk on psychosis. Finally, promoter polymorphisms impacted on prefrontal functioning as assessed by neuropsychological testing and electrophysiological parameters elicited by a Go-Nogo paradigm in 48 patients (continuous performance test). Collectively these findings suggest that regulatory polymorphisms of NOS1 contribute to the genetic risk for SCZ, and modulate prefrontal brain functioning.

Association between allelic variation of serotonin transporter function and neuroticism in anxious cluster C personality disorders

OBJECTIVE

Association between the low-activity variant of a polymorphism in the transcriptional control region of the serotonin transporter (5-HTTLPR) and neuroticism or harm avoidance was found in several but not all studies. The authors analyzed the influence of 5-HTTLPR variants on personality disorders.

METHOD

Patients with personality disorders (N=320) and healthy volunteers (N=281) were studied with the Revised NEO Personality Inventory and the Tridimensional Personality Questionnaire. All were genotyped for 5-HTTLPR variants.

RESULTS

No differences in 5-HTTLPR genotype distribution were detected between patients with cluster B and C personality disorders and comparison subjects. In contrast, among patients with a cluster C diagnosis, carriers of the low-activity short allele of the 5-HTTLPR exhibited higher neuroticism scores than noncarriers.

CONCLUSIONS

These findings support the notion that there is no general association between the 5-HTTLPR and anxiety-related traits and that differential gene effects and/or gene-by-environment interactions are likely operative in distinct clinical subpopulations.

Allelic variation in serotonin transporter function associated with the intensity dependence of the auditory evoked potential

The intensity dependence of the auditory evoked potential (AEP) has been suggested as an indicator of central serotonergic function, a strong intensity dependence presumably reflecting low serotonergic activity. As individual differences in serotonergic neurotransmission can be accounted for in part by genetic variation in genes of the serotonergic pathway, we investigated whether a functional polymorphism in the promoter region of the serotonin transporter gene (5-HTTLPR) is associated with the AEP intensity dependence. Because dopaminergic influences on the intensity dependence have also been reported, we furthermore explored the role of a functional polymorphism in the dopamine D4 receptor gene (DRD4 exon III) in the modulation of the AEP intensity dependence. AEPs to tones of six intensity levels were recorded from 60 healthy young individuals, and N1/P2 linear as well as median slopes at central electrode sites were computed as measures of the AEP intensity dependence. Analyses of variance showed that there was a significant effect of the 5-HTTLPR on the AEP intensity dependence. Individuals with the ll genotype exhibited a stronger intensity dependence compared to individuals with the ls genotype. This effect was even more pronounced when DRD4 exon III was considered in the analyses. In conclusion, these findings provide further evidence for a role of serotonergic neurotransmission in the modulation of the AEP intensity dependence. The results also point to possible dopaminergic influences on the AEP intensity dependence.

Allelic variation in 5-HT1A receptor expression is associated with anxiety- and depression-related personality traits

The 5-HT1A receptor plays a critical role in the pathophysiology of anxiety and depression as well as in the mode of action of anxiolytic and antidepressant drugs. Human 5-HT1A gene transcription is modulated by a common C-1016G single nucleotide polymorphism (SNP) in its upstream regulatory region. In the present study, we evaluated the role of the HTR1A-1019 polymorphism in the modulation of individual differences in personality traits by an association study of a sample of healthy volunteers. Personality traits were assessed with two different methods, NEO personality inventory (NEO-PI-R) and Tridimensional Personality Questionnaire (TPQ). There was a significant effect of the HTR1A-1019 polymorphism on NEO Neuroticism with carriers of the G allele showing higher scores than individuals homozygous for the C variant. The effect was primarily due to associations with the Neuroticism facets Anxiety and Depression. Carriers of the G allele also exhibited higher TPQ Harm Avoidance scores. Our findings indicate a role of allelic variation in 5-HT1A receptor expression in the development and modulation of anxiety- and depression-related personality traits.

Association between the dopamine D4 receptor (DRD4) exon III polymorphism and measures of Novelty Seeking in a German population

Since the observation of an association between the dopamine D4 receptor (DRD4) exon III polymorphism and the temperament trait of Novelty Seeking,1 replication studies have yielded both positive2-5 and negative6-12 results. This raised the question whether the initial findings must be regarded as false positives.13 However, demographic or methodological differences between studies may have obscured the small effect of the DRD4 polymorphism on Novelty Seeking.14 Examination of clinical or older cohorts may have led to an underestimation of possible associations due to a restricted variation of Novelty Seeking in these cohorts. The use of different questionnaires provides another source of variation. In order to replicate the initial findings as precisely as possible, a cohort of 136 healthy, young volunteers was genotyped, and Novelty Seeking was ascertained using the TPQ.15,16 In addition, further aspects of novelty seeking behavior have been ascertained through additional trait measures. We could observe the reported association between long DRD4 alleles and significantly elevated scores (age- and sex-residualized) on the TPQ-Novelty Seeking total scale as well as on two of the subscales, Exploratory Excitability and Extravagance. The results provide further confirmation for the role of the DRD4 exon III polymorphism in modulation of Novelty Seeking. In addition, the pattern of associations between the polymorphism and other scales suggests that this polymorphism has its effect on exploratory, extravagant, and extraverted, rather than on impulsive and monotony-avoidant subtypes of Novelty Seeking.

Effect of thiazolidinediones on expression of UCP2 and adipocyte markers in human PAZ6 adipocytes

AIMS/HYPOTHESIS

Thiazolidinediones, a new class of insulin sensitizers, up-regulate the expression of uncoupling protein 2 in rodent adipocytes. It is not known, however, whether thiazolidinediones influence uncoupling protein 2 expression in human adipocytes. We therefore investigated the effect of these drugs on uncoupling protein 2 expression in the recently immortalized human PAZ6 adipocyte cell line.

METHODS

Immortalized human PAZ6 preadipocytes were differentiated into adipocytes in the presence or absence of thiazolidinediones. The effect of the drugs on uncoupling protein 2 expression and adipocyte differentiation was measured by reverse transcription-polymerase chain reaction of mRNA of uncoupling protein 2 and of five adipocyte differentiation markers.

RESULTS

When cells were differentiated 15 days in the presence of thiazolidinediones, uncoupling protein 2 expression was 2.1-fold higher than in the absence of the drugs. The expression of five adipocyte differentiation markers was, however, also increased by thiazolidinediones. Short-term incubation for 4 and 24 h with thiazolidinediones increased uncoupling protein 2 expression 1.35-fold and 2.3-fold, respectively. The expression of adipocyte markers studied in parallel was also augmented.

CONCLUSION/INTERPRETATION

Thiazolidinediones rapidly increase the expression of uncoupling protein 2 in human PAZ6 adipocytes but the increase of uncoupling protein 2 expression is always associated with an augmentation of the expression of all adipocyte markers studied in parallel. This indicates that the effect of thiazolidinediones on uncoupling protein 2 mRNA reflects a general increase in adipocyte differentiation rather than a specific augmentation of uncoupling protein 2 gene expression.

Rat uncoupling protein 2 (UCP2): expression in obese ventromedial hypothalamus (VMH)-lesioned animals

BACKGROUND

The family of uncoupling proteins is thought to play an important role in the regulation of energy metabolism by uncoupling the respiratory chain reactions from ATP synthesis. The recently discovered uncoupling protein 2 (UCP2) is upregulated in genetically obese rodent models and during long term high fat feeding.

AIM

We have examined the UCP2 mRNA levels in liver, heart and white adipose tissue (WAT) of obese ventromedial hypothalamus (VMH)-lesioned rats, during the dynamic and the early stage of the static phase of obesity, before the appearance of most of the metabolic perturbations associated with long term established obesity.

RESULTS

The amount of UCP2 mRNA was not increased in any tissue of VMH-lesioned rats relative to control animals during the dynamic phase nor during the early static phase of obesity.

CONCLUSION

These results indicate that in the rat, obesity does not necessarily lead to an increase in UCP2 expression and suggest that the up-regulation of UCP2 described in other models may be secondary to metabolic perturbations, rather than to a direct adaptative response to the increased adipose tissue content of the organism.

Expression, activity and functional significance of inducible nitric oxide synthase in the failing human heart

OBJECTIVES

The study was designed to evaluate the functional impact of nitric oxide (NO) generation within the myocardium on cardiac contraction in the failing human heart.

BACKGROUND

Heart failure is associated with activation of cytokines and expression of inducible nitric oxide synthase (NOS II), which generates NO from L-arginine. Nitric oxide has been shown to modulate myocardial performance, raising the possibility that cardiac generation of NO by NOS II modulates cardiac contraction in the failing human heart.

METHODS

Left ventricular (LV) tissue of 24 patients with end-stage heart failure was obtained during cardiac transplantation. Gene expression of NOS II and endothelial NO-synthase (NOS III) was quantified by competitive reverse transcription-polymerase chain reaction and compared to tissues of five nonfailing donor hearts. Nitric oxide synthase II activity was determined by citrulline assay and related to changes in force of contraction induced by the beta-adrenergic agonist isoproterenol, NO-donors and/or N-mono-methyl-L-arginine (L-NMMA), an inhibitor of NOS.

RESULTS

While NOS III mRNA was reduced in failing hearts, NOS II mRNA was increased in failing LV tissue and correlated with NOS II activity. High NOS II activity was associated with early relaxation and impaired responsiveness to beta-adrenergic stimulation, that is, the inotropic response to isoproterenol in failing hearts was inversely related to NOS II activity (r=0.61, p < 0.005). Nitric oxide donors or L-NMMA did not affect myocardial performance in failing hearts at baseline. However, L-NMMA enhanced the positive inotropic response to beta-adrenergic stimulation in failing hearts with high NOS II activity. Nitric oxide donors attenuated the isoproterenol-induced increase in force of contraction of failing hearts.

CONCLUSIONS

Cardiac production of NO by NOS II attenuates the positive inotropic effects of beta-adrenergic stimulation and hastens relaxation in failing human hearts.