Validation of the CARPREG II risk stratification model and the WHOm scale in pregnant women with heart disease

 

The physiological changes of pregnancy imply a state of haemodynamic stress, which increases the risk of maternal-fetal complications in women with cardiac pathology. Risk stratification models allow clinical decisions to be guided and optimal diagnostic, follow-up and management strategies to be established according to each estimated category in order to reduce adverse outcomes.

Objective

To validate the CARPREG II and WHOm risk prediction models in a population of pregnant women with heart disease.

Materials and methods

Validation and comparison study of a risk prediction model in a prospective cohort of pregnant women with heart disease assessed between 2016 and 2019 by a cardiobstetric team in an average income country. The CARPREG II score was established and patients were classified according to the WHOm risk scale. We assessed cardiovascular and perinatal outcomes and determined the calibration and level of discrimination of these tools.

Results

In a cohort of 328 pregnant women (27±7 years), 33% (n=110) had congenital heart disease, followed by arrhythmias in 30% (n=98), valvular pathologies in 14% (n=46) and cardiomyopathies in 9% (n=29). In 56% of the pregnancies, the route of delivery was caesarean section, 84% of these by obstetric indication. A cardiac event occurred in 15%, with left heart failure (5.3%) and arrhythmias (2.3%) being the most frequent. The frequency of maternal death of cardiac origin during the study was 1.6%. Neonatal outcomes occurred in 37% of gestations (preterm delivery (16%) and low weight for gestational age (8.4%)) and obstetric events in 12.5%: pregnancy-induced hypertension (9%) and postpartum haemorrhage (2.3%).

NYHA functional class III-IV or cyanosis (OR 12 95% CI 3.1 - 46.4) and left ventricular dysfunction (LVEF <55%) (OR 3 95% CI 1 - 10.9) were the most statistically significant risk predictors. Discrimination of both models was adequate (AUC-ROC of 0.74 95% CI 0.64 - 0.84) for the CARPREG II risk index and 0.77 for the WHOm scale (95% CI 0.69 - 0.86) (Figure 2). Calibration is also good in the study population (Hosmer- Lemeshow goodness-of-fit 0.6 and 0.1, respectively). By including in the CARPREG II model the variables ejection fraction and pulmonary artery systolic pressure in their numerical and not dichotomised form, a discrete improvement in the predictive ability of the scale is evident (AUC-ROC 0.81 95% CI 0.71–0.91).

Conclusions

The CARPREG II and WHOm risk stratification models have good ability to discriminate the risk of adverse cardiac outcomes in pregnant women with heart disease and fit our population. To improve the predictive power of CARPREG II, the variables pulmonary hypertension and left ventricular dysfunction could be used numerically and not dichotomised as in the original model.

Funding Acknowledgement

Type of funding sources: Private hospital(s). Main funding source(s): San Vicente Foundation University Hospital, Cardio-obstetric Center

Defining global benchmarks in elective secondary bariatric surgery comprising conversional, revisional and reversal procedures

Objective

Management of poor response and of long-term complications after bariatric surgery (BS) is complex and under-investigated. Indications and types of reoperations vary widely and postoperative complication rates are higher compared to primary BS. Benchmarking uses best performance in a given field as reference point for improvement. Our aim was to define ‘‘best possible’’ outcomes for elective secondary BS.

Methods

The establishment of benchmarks in secondary BS followed a standardized methodology, based on recommendations of a Delphi consensus panel of experts. This multicenter study analyzed patients undergoing elective secondary BS in 18 high-volume centers on 4 continents from 06/2013 to 05/2019. Twenty-one outcome benchmarks were established in low-risk patients, defined as the 75th percentile of the median outcome values of the centers. Benchmark cases had no: previous laparotomy, diabetes, sleep apnea, cardiopathy, renal insufficiency, inflammatory bowel disease, immunosuppression, history of thromboembolic events, BMI>50kg/m2 or age>65 years. Descriptive statistics, multivariate logistic regression and data visualization were performed using the R software.

Results

Out of 44’884 elective bariatric procedures performed in the participating centers, 5’328 secondary BS cases were identified. The benchmark cohort included 3143 cases, mainly females (85%), aged 43.8±10 years, 8.4±5.3 years after primary BS, with a body mass index 35.2±7kg/m2. Main indications were insufficient weight loss (43%) and gastro-esophageal reflux disease/dysphagia (25%). 90-days postoperatively, 14.57% of benchmark patients presented ≥1 complication, mortality was 0.06% (n = 2). Significantly higher morbidity was observed in non-benchmark cases (OR 1.36) and after conversional or revisional procedures with gastrointestinal suture/stapling (OR 1.7). Benchmark cutoffs at 90-days postoperatively were ≤5.8% re-intervention and ≤8.8% re-operation rate. At 2-years (IQR 1-3) 15.6% of benchmark patients required a reoperation.

Conclusion

Secondary BS is safe, although postoperative morbidity exceeds the established benchmarks for primary BS. The excess morbidity is due to an increased risk of gastrointestinal leakage and higher need for intensive care. The considerable rate of tertiary BS warrants expertise and future research to optimize the management of non-success after BS.

ACTIVATE: the effect of aclidinium/formoterol on hyperinflation, exercise capacity, and physical activity in patients with COPD

The Phase IV, 8-week, randomized, double-blind, placebo-controlled ACTIVATE study (NCT02424344) evaluated the effect of aclidinium/formoterol (AB/FF) 400/12 μg twice daily on lung hyperinflation, exercise capacity, and physical activity in patients with moderate-to-severe COPD. Patients received AB/FF (n=134) or placebo (n=133) (1:1) via the Genuair™/Pressair^® dry powder inhaler for 8 weeks. From Weeks 5 to 8, all patients participated in behavioral intervention (BI; daily messages providing step goals). The primary end point was trough functional residual capacity (FRC) at Week 4. Exercise endurance time and physical activity were assessed at Week 4 (pharmacotherapy only) and at Week 8 (8 weeks of pharmacotherapy plus 4 weeks of BI). Other end points included post-dose FRC, residual volume, and inspiratory capacity (IC) at rest and during exercise. After 4 weeks, trough FRC improved with AB/FF versus placebo but did not reach significance (125 mL; P=0.0690). However, post-dose FRC, residual volume, and IC at rest improved significantly with AB/FF at Week 4 versus placebo (all P<0.0001). AB/FF significantly improved exercise endurance time and IC at isotime versus placebo at Week 4 (P<0.01 and P<0.0001, respectively) and Week 8 (P<0.05 and P<0.0001, respectively). AB/FF achieved higher step counts (P<0.01) with fewer inactive patients (P<0.0001) at Week 4 versus placebo. Following BI, AB/FF maintained improvements in physical activity at Week 8 and nonsignificant improvements were observed with placebo. AB/FF 400/12 μg demonstrated improvements in lung hyperinflation, exercise capacity, and physical activity versus placebo that were maintained following the addition of BI. A 4-week period of BI might be too short to augment the improvements of physical activity observed with AB/FF.

Portomesenteric Vein Thrombosis After Laparoscopic Sleeve Gastrectomy: Incidence, Analysis and Follow-Up in 1236 Consecutive Cases

BACKGROUND

Portomesenteric vein thrombosis (PMVT) is a rare but severe complication after laparoscopic bariatric surgery, with potentially serious consequences. We aimed to describe the incidence, clinical features, management, outcome, and midterm follow-up in patients with PMVT after laparoscopic sleeve gastrectomy (LSG).

METHODS

This retrospective and descriptive study included patients who underwent LSG between November 2009 and July 2015 and developed PMVT. The following data were analyzed: age, gender, body mass index (BMI), thrombosis risk factors, surgical technique, thromboembolic prophylaxis, primary surgery outcomes, clinical features, treatment, thrombophilia testing results, and follow-up findings, including imaging and endoscopic findings.

RESULTS

A total of 1236 patients underwent LSG, and 5 (0.4 %) developed PMVT. The mean age was 34.4 years, and 3 patients were women. The mean BMI was 38.5 kg/m2. Two patients had received hormonal contraceptive treatment. Four patients had a history of smoking. All of the patients received anticoagulant treatment, and none required surgery. The mean hospitalization duration was 7.6 days. Two patients showed complete recanalization. One patient showed portal cavernomatosis on delayed images. Two patients had a positive thrombophilia test. No portal hypertension endoscopic findings were observed.

CONCLUSIONS

PMVT is a rare complication, for which smoking was identified as a predominant risk factor. Early diagnosis and prompt anticoagulant therapy could lead to a dramatic decrease in the incidence of intestinal infarction, mortality, and extrahepatic portal hypertension in the near future. However, careful follow-up is necessary to evaluate the impact of PMVT on long-term patient outcomes.

Fenofibrate subcellular distribution as a rationale for the intracranial delivery through biodegradable carrier

Fenofibrate, a well-known normolipidemic drug, has been shown to exert strong anticancer effects against tumors of neuroectodermal origin including glioblastoma. Although some pharmacokinetic studies were performed in the past, data are still needed about the detailed subcellular and tissue distribution of fenofibrate (FF) and its active metabolite, fenofibric acid (FA), especially in respect to the treatment of intracranial tumors. We used high performance liquid chromatography (HPLC) to elucidate the intracellular, tissue and body fluid distribution of FF and FA after oral administration of the drug to mice bearing intracranial glioblastoma. Following the treatment, FF was quickly cleaved to FA by blood esterases and FA was detected in the blood, urine, liver, kidney, spleen and lungs. We have also detected small amounts of FA in the brains of two out of six mice, but not in the brain tumor tissue. The lack of FF and FA in the intracranial tumors prompted us to develop a new method for intracranial delivery of FF. We have prepared and tested in vitro biodegradable poly-lactic-co-glycolic acid (PLGA) polymer wafers containing FF, which could ultimately be inserted into the brain cavity following resection of the brain tumor. HPLC-based analysis demonstrated a slow and constant diffusion of FF from the wafer, and the released FF abolished clonogenic growth of glioblastoma cells. On the intracellular level, FF and FA were both present in the cytosolic fraction. Surprisingly, we also detected FF, but not FA in the cell membrane fraction. Electron paramagnetic resonance spectroscopy applied to spin-labeled phospholipid model-membranes revealed broadening of lipid phase transitions and decrease of membrane polarity induced by fenofibrate. Our results indicate that the membrane-bound FF could contribute to its exceptional anticancer potential in comparison to other lipid-lowering drugs, and advocate for intracranial delivery of FF in the combined pharmacotherapy against glioblastoma.

Light-induced catalytic transformation of ofloxacin by solar Fenton in various water matrices at a pilot plant: mineralization and characterization of major intermediate products

This work investigated the application of a solar driven advanced oxidation process (solar Fenton), for the degradation of the antibiotic ofloxacin (OFX) in various environmental matrices at a pilot-scale. All experiments were carried out in a compound parabolic collector pilot plant in the presence of doses of H2O2 (2.5 mg L(-1)) and at an initial Fe(2+) concentration of 2 mg L(-1). The water matrices used for the solar Fenton experiments were: demineralized water (DW), simulated natural freshwater (SW), simulated effluent from municipal wastewater treatment plant (SWW) and pre-treated real effluent from municipal wastewater treatment plant (RE) to which OFX had been spiked at 10 mg L(-1). Dissolved organic carbon removal was found to be dependent on the chemical composition of the water matrix. OFX mineralization was higher in DW (78.1%) than in SW (58.3%) at 12 mg L(-1) of H2O2 consumption, implying the complexation of iron or the scavenging of hydroxyl radicals by the inorganic ions present in SW. On the other hand, the presence of dissolved organic matter (DOM) in SWW and RE, led to lower mineralization per dose of H2O2 compared to DW and SW. The major transformation products (TPs) formed during the solar Fenton treatment of OFX, were elucidated using liquid chromatography-time of flight-mass spectrometry (LC-ToF-MS). The transformation of OFX proceeded through a defluorination reaction, accompanied by some degree of piperazine and quinolone substituent transformation while a hydroxylation mechanism occurred by attack of the hydroxyl radicals generated during the process leading to the formation of TPs in all the water matrices, seven of which were tentatively identified. The results obtained from the toxicity bioassays indicated that the toxicity originates from the DOM present in RE and its oxidation products formed during the photocatalytic treatment and not from the TPs resulted from the oxidation of OFX.

Solar photocatalytic treatment of trimethoprim in four environmental matrices at a pilot scale: transformation products and ecotoxicity evaluation

The pilot-scale solar degradation of trimethoprim (TMP) in different water matrices (demineralized water: DW, simulated natural freshwater: SW; simulated wastewater: SWW; and real effluent: RE) was investigated in this study. DOC removal was lower in the case of SW compared to DW, which can be attributed to the presence of inorganic anions which may act as scavengers of the HO·. Furthermore, the presence of organic carbon and higher salt content in SWW and RE led to lower mineralization per dose of hydrogen peroxide compared to DW and SW. Toxicity assays in SWW and RE were also performed indicating that toxicity is attributed to the compounds present in RE and their by-products formed during solar Fenton treatment and not to the intermediates formed by the oxidation of TMP. A large number of compounds generated by the photocatalytic transformation of TMP were identified by UPLC-QToF/MS. The degradation pathway revealed differences among the four matrices; however hydroxylation, demethylation and cleavage reactions were observed in all matrices. To the best of our knowledge this is the first time that TMP degradation products have been identified by adopting a solar Fenton process at a pilot-scale set-up, using four different aqueous matrices.

Stable angina in Spain and its impact on quality of life. The AVANCE registry

INTRODUCTION AND OBJECTIVES

Mortality from acute coronary syndrome has fallen but a substantial number of chronic patients remain symptomatic. The present study was designed to determine the clinical characteristics and therapeutic treatment of patients with stable angina and its impact on their quality of life.

METHODS

A cross-sectional, multicenter, observational study of 2039 patients with stable angina attended in outpatient clinics was performed. Data were collected on clinical variables and on the subjective perception of the severity of angina and the resulting limitations. Patients completed questionnaires on their perception of severity and quality of life.

RESULTS

We analyzed data on 2024 patients; 73% were men (mean age 68[10] years). Some 50.3% were asymptomatic (<1 angina attack per week in the previous 4 weeks), 39.2% reported 1-3 attacks per week and 10.5% reported >3 attacks per week; 66% had previously undergone revascularization, and 59% of these developed recurrent angina. Patients rated the severity of their condition higher than did their physicians (4.5 [2.5] vs 4.3 [2.3]; P=.002). Physicians' and patients' perceptions of the repercussions of angina showed little concordance (kappa<0.3). The patients believed their condition was much more severe, more debilitating, and had a greater negative impact on their quality of life.

CONCLUSIONS

A high proportion of patients with stable angina remains symptomatic and their quality of life is impaired. Their perception of the condition is worse than that of their physicians.

[Home parenteral nutrition registry in Spain for the year 2010: NADYA-SENPE Group]

OBJECTIVES

To report the Group Registry NADYASENPE data about home parenteral nutrition (HPN) in Spain in 2010.

MATERIAL AND METHODS

A descriptive study of the database of the national registry of HPN of NADYA-SENPE (December 10, 2009 to December 10, 2010). For the calculation of prevalence the latest data published by the Institute National Statistics Office (01/01/2009) was used.

RESULTS

There were registered 148 patients from 23 hospitals, 86 women (58.11%) and 9 children (6.08%). The average age of the 139 patients older than 14 years was 53.06 ± 15.41 years. The average duration of HPN was 316.97 days/patient. The most common diagnosis in those younger than 14 years was short bowel traumatic with 5 cases (55.55%) and in those older than 14 years, palliative care cancer with 29 cases (19.59%). The reason for the indication for HPN was short bowel syndrome in 74 cases (47%). The access via most frequently recorded was tunneled catheter in 36 cases (22.78%) followed by implanted port-catheters in 13 cases (8.23%) and other pathways in 3 cases (1.90%). There were 23 catheterrelated infections (82.14%) which represented 0.49 /1,000 days of PN, all of which occurred in cases older than 14 years. During the year 24 episodes of HPN ended, the most frequent cause was the transition to oral nutrition in 12 episodes (50%). It was reported that patients had a normal activity in 70 episodes of HPN (44.30%) with complete autonomy in 88 episodes (55.69%). Some patients 39 (24.68%) were potential candidates for intestinal transplantation.

CONCLUSIONS

The number of registered patients is slightly lower than the previous year, although the number of participating hospitals is the same. The most frequent complication remains catheter-related infection but its incidence has decreased from previous years, presenting the lowest rate since the creation of the record. Differences in participation in the registry observed in the Autonomous Communities causes the development of implementation strategies. There is a gradual increase in day length of HPN over the years, which suggests the chronic treatments of some patients and obliges to study the existence of a possible confounding factor, in case there is an oversight of closing an episode. Therefore, it is necessary to update the registry with warning systems that facilitate periodic review of the patients and optimize the validity of registration.

[How beta-blockers are used in Spain? Analysis of limitations in their use in internal medicine and cardiology: CARACTER-BETA study]

INTRODUCTION AND OBJECTIVES

Beta-blocker treatment has a class I indication, level of evidence A, in guidelines for the treatment of heart failure, ischemic heart disease, and atrial fibrillation. However, beta-blocker use continues to be less than optimal. In this study, beta blocker use in Spain is analyzed in patients with heart failure, ischemic heart disease, and atrial fibrillation.

METHODS

Observational, epidemiologic, cross-sectional, multicenter study including 1608 patients with heart failure, ischemic heart disease, and/or atrial fibrillation, recruited in 150 healthcare centers by cardiologists and internal medicine specialists.

RESULTS

Cardiologists enrolled 78.6% patients and internal medicine specialists 21.4%; 25.8% were recruited at hospital discharge and 74.2% at outpatient centers. Men accounted for 77% of the sample, and age was 68 (12) years. Of the total, 73% had ischemic heart disease, 42% heart failure, and 36% atrial fibrillation (multiresponse variable). Beta blockers were given to 82.8% of those consulting in cardiology compared to 71.6% of those treated in internal medicine (P<.0001). By pathology, the prescription rate was 85.1% of patients with ischemic heart disease, 77.0% of those with heart failure, and 72.4% of those with atrial fibrillation. Cardiology prescribed significantly more beta blockers for ischemic heart disease and heart failure than did internal medicine. Multivariate analysis showed that beta blocker use increased when the patient had ischemic heart disease, was treated by a cardiologist, and had dyslipidemia, stroke, and/or left ventricular hypertrophy. beta blocker use decreased with age and with a history of bronchospasm, asthma, bradycardia, chronic obstructive pulmonary disease, and/or intermittent claudication.

CONCLUSIONS

There is still room for improvement in beta blocker prescription in Spain for patients with ischemic heart disease, heart failure, and/or atrial fibrillation.

[The Spanish Home Enteral Nutrition registry of the year 2009: from the NADYA-SENPE group]

OBJECTIVE

To describe the Home Enteral Nutrition Characteristics (HEN) recorded by the group NADYA-SENPE during 2009.

MATERIAL AND METHOD

collection and analysis of the data voluntary recorded in the HEN registry from the NADYA-SENPE group from January 1st to December 31st.

RESULTS

6.540 HEN patients were registered, 5.11% more than the previous year and 6,649 episodes (3,135 in women, 47,93%) from 32 different hospitals. 6,238 of them (95,38%) were over 14 years. The mean age of the patients under 14 yr was 3,67 ± 2,86 and it was 72,10 ± 16,89 in those over 14 yr group. The base illness registered more frequently was the neurological disorders in 2,732 (41,77%) patients, followed by cancer patients in 1,838; 28,10%. The enteral access route was registered in 1,123 (17,17%) of the episodes, being more frequent the administration by nasogastric tube 562 (50,04%). The mean length of nutritional treatment by episode was 323 days (10,77 months). 606 episodes of HEN ended, being the principal reasons for discontinuing treatment the patient death in 295 (48,68%) occasions. The transition to oral feeding occurred in 219 (36,14%) cases. Patients maintained normal activity in 2162 (32,55%) HEN episodes and 2,468 (37,13%) cases were living "bed-couch". The level of dependence was "total" in 2,598 (39,07%) of the episodes recorded. The nutritional formula was provided by the hospital in 4,183 (62,91%) cases and by the reference pharmacy in 2,262 (el 34,02%). Consumables were provided by the hospital in 3,531 (53,11%) cases.

CONCLUSIONS

The number of HEN patients recorded increased from the year 2008, continuing the gradual growth increase since the start of registration. The characteristics of the patients remain in the same profile as in previous years.

Validation of the Spanish version of the Kansas city cardiomyopathy questionnaire

INTRODUCTION AND OBJECTIVES

The Kansas City Cardiomyopathy Questionnaire (KCCQ) is specifically designed to evaluate quality of life in patients with chronic heart failure (CHF). The purpose of this study was to assess the reliability, validity, and responsiveness to change of the Spanish version of the KCCQ.

METHODS

The multicenter study involved 315 patients with CHF. Patients were evaluated at baseline and at weeks 24 and 26. The KCCQ, the Minnesota Living with Heart Failure Questionnaire (MLHFQ), and the Short Form-36 (SF-36) were administered. Reliability was assessed in stable patients (n=163) by examining test-retest and internal consistency measures between weeks 24 and 26. Validity was evaluated at baseline (n=315) by determining how KCCQ scores varied with New York Heart Association functional class and by comparing scores with those on similar domains of the MLHFQ and SF-36. Responsiveness to change was assessed in patients who experienced significant clinical improvement between baseline and week 24 (n=31) by determining the effect size.

RESULTS

Reliability coefficients ranged between 0.70 and 0.96 for the different domains. Mean KCCQ scores varied significantly with New York Heart Association functional class (P<.001). Correlations with comparable domains on the other questionnaires were acceptable (e.g. for physical limitation, they were between 0.77 and 0.81). The changes observed at 24 weeks in the majority of KCCQ scores in the subsample that improved corresponded to a moderate effect size (i.e. 0.4-0.6).

CONCLUSIONS

The Spanish version of the KCCQ has good metric properties (i.e. validity, reliability and responsiveness), which make it suitable for use in evaluating quality of life in Spanish CHF patients.

[Spanish home enteral nutrition (HEN) registry of the year 2008 from the NADYA-SENPE group]

AIM

To present the results of the Spanish home enteral nutrition (HEN) registry of the year 2008 from the NADYA-SENPE group.

MATERIAL AND METHODS

We recorded the HEN registry data from January 1st to December 31st 2008.

RESULTS

The number of patients registered in this period was 6206 (51% male) with up to 6,279 episodes of HEN, from 31 Spanish hospitals. Most of the patients (95%) were older than 14 yr. Mean age was 4.83±3.29 yr in the children group, and 70.75±18.14 yr in the adult group (older than 14 yr). Neurological disorders (39%) and cancer (27%) were the two most prevalent diagnoses. The oral route was the most frequently used (43,4%), followed by nasogastric tube (40,4%), and gastrostomy tube (14,7%). Mean length of treatment was 305,36 days (10 months). The principal reasons for discontinuing treatment were death (43%) and progress to oral diet (40%). Only 33% of the patients had a normal activity level, being limited in different grades in the rest of the patients. Most of the patients required partial (25%) or total help (38%). The enteral formula was provided by the hospital in 65% of the cases and by private pharmacies in 32%. The disposables were provided by the hospital (82,4%) and primary care services (17,2%).

CONCLUSIONS

The number and the age of the patients registered have increased comparing to previous years, with little variations in the rest of analyzed variables. The increase in the length of treatment could reflect misreporting of the weaning process in the registry.

Effect of a training program for primary care physicians on the optimization of beta-blocker treatment in elderly patients with heart failure

INTRODUCTION AND OBJECTIVES

Underuse of betablockers may contribute to elevated mortality in chronic heart failure. The aim of this study was to determine whether a specific interventional training program for primary care physicians would help optimize the use of beta-blockers in elderly chronic heart failure patients.

METHODS

This randomized comparative study included 627 patients aged 70 years or more who were discharged consecutively from 53 Spanish hospitals with a principal diagnosis of chronic heart failure. In total, 292 health-care centers in the catchment areas of these hospitals were randomly assigned to two groups: one group of 146 centers carried out an interventional training program on beta-blocker use for primary care physicians belonging to the centers assigned to training, and 146 centers served as a control group. The main outcome variable was the percentage of patients who were receiving a beta-blocker at the maximum or maximum tolerated dose 3 months after hospital discharge.

RESULTS

The patients' mean age was 78+/-5 years and 42% were women. There was no difference between the groups in demographic characteristics, clinical care, or treatment at discharge. The percentage of patients who received beta-blockers at the maximum tolerated dose 3 months after discharge was greater in the training group (49% vs. 38%; P=.014). Being treated in the training group was an independent predictor of receiving a beta-blocker at the MTD (odds ratio=2.46; 95% confidence interval, 1.29-4.69; P< .001).

CONCLUSIONS

Implementation of an interventional training program on beta-blocker treatment for primary care physicians improved the use of these medications in elderly chronic heart failure patients.

[National registry of home enteral nutrition in Spain 2007]

OBJECTIVE

To communicate the results from the registry of Home-Based Enteral Nutrition of the NADYASENPE group in 2007.

MATERIAL AND METHODS

We included every patient in the registry with home enteral nutrition any time from January 1st to December 31st of 2007.

RESULTS

The number of patients with home enteral nutrition in 2007 was 5,107 (52% male) from 28 different hospitals. 95.4% of them were 15 yr or older, with a mean age of 67.96 +/- 18.12, and 4.2 +/- 3.38 among patients aged 14 yr or less. The most common underlying diseases were neurological (37.8%) and neoplastic diseases (29.3%). Enteral nutrition was administered p.o. in most patients (63.5%), followed by nasogastric tube (25.9%), while gastrostomy was only used in 9.2%. The mean time in enteral nutrition support was 9.4 months and the most common reasons for withdrawal were death (58.7%) and switching to oral intake (32%). Activity was limited in 31.4% of patients and 36.01% were house-bound. Most patients needed partial (26.51%) or total (37.68%) care assistance. Enteral formula was provided by hospitals to 69.14% of patients and by pharmacies to 30.17% of them, while disposable material was provided by hospitals to 81.63% and by Primary Care to the remaining patients.

CONCLUSIONS

In 2007, there has been an increase of more than 30% of patients registered with home enteral nutrition comparing with 2006, without any big difference in other data, but a higher proportion of patients with enteral nutrition p.o.

Mu opioid receptor modulation of somatodendritic dopamine overflow: GABAergic and glutamatergic mechanisms

Mu opioid receptor (MOR) regulation of somatodendritic dopamine neurotransmission in the ventral tegmental area (VTA) was investigated using conventional microdialysis in freely moving rats and mice. Reverse dialysis of the MOR agonist DAMGO (50 and 100 microm) into the VTA of rats produced a concentration-dependent increase in dialysate dopamine concentrations. Basal dopamine overflow in the VTA was unaltered in mice lacking the MOR gene. However, basal gamma-aminobutyric acid (GABA) overflow in these animals was significantly increased, whereas glutamate overflow was decreased. Intra-VTA perfusion of DAMGO into wild-type (WT) mice increased dopamine overflow. GABA concentrations were decreased, whereas glutamate concentrations in the VTA were unaltered. Consistent with the loss of MOR, no effect of DAMGO was observed in MOR knockout (KO) mice. These data provide the first direct demonstration of tonically active MOR systems in the VTA that regulate basal glutamatergic and GABAergic neurotransmission in this region. We hypothesize that increased GABAergic neurotransmission following constitutive deletion of MOR is due to the elimination of a tonic inhibitory influence of MOR on GABAergic neurons in the VTA, whereas decreased glutamatergic neurotransmission in MOR KO mice is a consequence of intensified GABA tone on glutamatergic neurons and/or terminals. As a consequence, somatodendritic dopamine release is unaltered. Furthermore, MOR KO mice do not exhibit the positive correlation between basal dopamine levels and the glutamate/GABA ratio observed in WT mice. Together, our findings indicate a critical role of VTA MOR in maintaining an intricate balance between excitatory and inhibitory inputs to dopaminergic neurons.

Solar photo-Fenton as finishing step for biological treatment of a pharmaceutical wastewater

Remediation of pharmaceutical wastewater, containing nalidixic acid (NXA; 38 mg/L), a quinolone antibacterial agent commonly used in human and veterinary medicine, and characterized as having mainly 725 mg/L dissolved organic carbon (DOC), 3400 mg/L chemical oxygen demand, and around 4 g/L NaCl, was studied. A prior biodegradability study (Zahn-Wellens test) had demonstrated that the matrix was biodegradable after a rather long biomass adaptation period. After 4 days of treatment in an immobilized biomass reactor (IBR), 96% of the original DOC was removed by the biological treatment however, more than 50% of NXA was adsorbed on the biomass. As development of chronic toxicity in the IBR is possible after long exposure to NXA, adsorption and biomass stability during continuous exposure to NXA were studied in different cycles for one month. Afterthe biotreatment, the effluent was treated by solar photo-Fenton. Total degradation of NXA and reduction in toxicity were observed. The intermediates formed during degradation by biotreatment and subsequent photo-Fenton were studied by liquid chromatography-time-of-flight mass spectrometry.

Decontamination industrial pharmaceutical wastewater by combining solar photo-Fenton and biological treatment

Characterization and treatment of a real pharmaceutical wastewater containing 775 mg dissolved organic carbon per liter by a solar photo-Fenton/biotreatment were studied. There were also many inorganic compounds present in the matrix. The most important chemical in this wastewater was nalidixic acid (45 mg/L), an antibiotic pertaining to the quinolone group. A Zahn-Wellens test demonstrated that the real bulk organic content of the wastewater was biodegradable, but only after long biomass adaptation; however, the nalidixic acid concentration remained constant, showing that it cannot be biodegraded. An alternative is chemical oxidation (photo-Fenton process) first to enhance biodegradability, followed by a biological treatment (Immobilized Biomass Reactor--IBR). In this case, two studies of photo-Fenton treatment of the real wastewater were performed, one with an excess of H2O2 (kinetic study) and another with controlled H2O2 dosing (biodegradability and toxicity studies). In the kinetic study, nalidixic acid completely disappeared after 190 min. In the other experiment with controlled H2O2, nalidixic acid degradation was complete at 66 mM of H2O2 consumed. Biodegradability and toxicity bioassays showed that photo-Fenton should be performed until total degradation of nalidixic acid before coupling a biological treatment. Analysis of the average oxidation state (AOS) demonstrated the formation of more oxidized intermediates. With this information, the photo-Fenton treatment time (190 min) and H2O2 dose (66 mM) necessary for adequate biodegradability of the wastewater could be determined. An IBR operated in batch mode was able to reduce the remaining DOC to less than 35 mg/L. Ammonium consumption and NO3- generation demonstrated that nitrification was also attained in the IBR. Overall DOC degradation efficiency of the combined photo-Fenton and biological treatment was over 95%, of which 33% correspond to the solar photochemical process and 62% to the biological treatment.

The dopamine D3/D2 agonist (+)-PD-128,907 [(R-(+)-trans-3,4a,10b-tetrahydro-4-propyl-2H,5H-[1]benzopyrano[4,3-b]-1,4-oxazin-9-ol)] protects against acute and cocaine-kindled seizures in mice: further evidence for the involvement of D3 receptors

Previous findings have demonstrated a protective role for dopamine D(3)/D(2) receptor agonists in the convulsant and lethal effects of acutely administered cocaine. Data are provided here to establish that the protection occurs through a D(3)-linked mechanism and that protection is extended to seizure kindling. The D(3) antagonist SB-277011-A [4-quinolinecarboxamide,N-[trans-4-[2-(6-cyano-3,4-dihydro-2(1H)-isoquinolinyl)ethyl]-cyclohexyl]-(9CI)] prevented the anticonvulsant effect of the D(3)/D(2) receptor agonist (+)-PD-128,907 [(R-(+)-trans-3,4a,10b-tetrahydro-4-propyl-2H,5H-[1]benzopyrano[4,3-b]-1,4-oxazin-9-ol)] on cocaine-induced seizures. The protection afforded by the D(3)/D(2) agonist, (+)-PD-128,907, was eliminated in D(3) receptor-deficient mice. In D(2) receptor knockout mice, the anticonvulsant effects of (+)-PD-128,907 were preserved. (+)-PD-128,907 also prevented the acquisition and expression of cocaine-kindled seizures engendered by repeated daily dosing with 60 mg/kg cocaine. (+)-PD-128,907 also blocked the seizures induced in mice fully seizure kindled to cocaine. Although repeated dosing with cocaine increased the potency of cocaine to produce seizures and lethality (decreased ED(50) values), daily coadministration of (+)-PD-128,907 significantly prevented this potency shift. In mice treated daily with cocaine and (+)-PD-128,907, the density, but not the affinity, of D(3) receptors was increased. The specificity with which (+)-PD-128,907 acts upon this cocaine-driven process was demonstrated by the lack of a significant effect of (+)-PD-128,907 on seizure kindling to a GABA(A) receptor antagonist, pentylenetetrazol. Taken together and with literature findings, the data indicate that dopamine D(3) receptors function in the initiation of a dampening mechanism against the toxic effects of cocaine, a finding that might have relevance to psychiatric disorders of drug dependence, schizophrenia, and bipolar depression.

[Registry of home-based enteral nutrition in Spain for the year 2006 (NADYA-SENPE Group)]

OBJECTIVE

To communicate the results obtained from the registry of Home-Based Enteral Nutrition (HBEN) of the NADYA-SENPE group for the year 2006.

MATERIAL AND METHODS

Recompilation of the data from the HBEN registry of the NADYA-SENPE group from January 1st to December 31st of 2006.

RESULTS

During the year 2006, 3,921 patients (51% men) from 27 hospital centers were registered. Ninety-seven percent were older than 14 years. The mean age for those < 14 years was 4.9 +/- 3.9 (m +/- SD) and in those > or = 14 years, it was 68.5 +/- 18.2 years. The most common underlying disease was neurological pathology (42%), followed by cancer (28%). Enteral nutrition was administered p.o. in 44% of the patients, through nasogastric tube in 40%, gastrostomy in 14%, and jejunostomy in 1%. The average time of nutritional support was 8.8 months. The most common reasons for ending the therapy were patient's death (54%) and switching to oral feeding (32%). Thirty-one percent of the patients presented a limited activity and 40% were confined to bed/coach. Most of the patients required partial (25%) or total (43%) care assistance. The nutritional formula was provided by the hospital in 62% of the cases and from the reference pharmacy in 27%. The fungible material was provided by the hospital in 80% of the cases and by primary care in the remaining patients.

CONCLUSIONS

Although the number of registered patients is slightly higher than that from the last years, there are no important changes in the patients characteristics, or way of administration and duration of enteral nutrition.

Dynorphin and the pathophysiology of drug addiction

Drug addiction is a chronic relapsing disease in which drug administration becomes the primary stimulus that drives behavior regardless of the adverse consequence that may ensue. As drug use becomes more compulsive, motivation for natural rewards that normally drive behavior decreases. The discontinuation of drug use is associated with somatic signs of withdrawal, dysphoria, anxiety, and anhedonia. These consequences of drug use are thought to contribute to the maintenance of drug use and to the reinstatement of compulsive drug use that occurs during the early phase of abstinence. Even, however, after prolonged periods of abstinence, 80-90% of human addicts relapse to addiction, suggesting that repeated drug use produces enduring changes in brain circuits that subserve incentive motivation and stimulus-response (habit) learning. A major goal of addiction research is the identification of the neural mechanisms by which drugs of abuse produce these effects. This article will review data showing that the dynorphin/kappa-opioid receptor (KOPr) system serves an essential function in opposing alterations in behavior and brain neurochemistry that occur as a consequence of repeated drug use and that aberrant activity of this system may not only contribute to the dysregulation of behavior that characterizes addiction but to individual differences in vulnerability to the pharmacological actions of cocaine and alcohol. We will provide evidence that the repeated administration of cocaine and alcohol up-regulates the dynorphin/KOPr system and that pharmacological treatments that target this system may prove effective in the treatment of drug addiction.

[Spanish registry of Home-Based Parenteral Nutrition for the years 2004 and 2005 (NADYA-SENPE Group)]

OBJECTIVE

To report the results of the Home Parenteral Nutrition (HPN) registry of the NADYA-SENPE working group of the years 2004 and 2005.

MATERIAL AND METHODS

We summarized the data of the new on-line HPN registry of the NADYA-SENPE group for the period 2004-2005.

RESULTS

During the year 2004, 70 HPN-patients (23 males and 47 females) were registered from 14 hospitals. Mean age of adults was 53,7 +/- 14,87 years (m +/- SD) and 6 +/- 2,83 years for those younger than 14 years. The most frequent etiologies of the intestinal failure were neoplasia (24%) and mesenteric ischaemia (19%). Tunnelled catheters were used in 75% of the patients. The catheter-related infections were the most frequent complications, with a rate of 0,98 episodes/10(3) days. In 69% of the cases the nutritional support was maintained for more than 2 years. HPN solutions and disposables were supplied by the hospital pharmacy in 81% and 83%, respectively. Up to 54% of the patients had a normal activity level. The most frequent reasons to end HPN treatment were the transition to oral intake (41%), or exitus (28%). During the year 2005, 79 patients (33 males and 46 females) were registered from 14 hospitals. Mean age of adults was 52,39 +/- 14,21 years and 6,5 +/- 5,21 years for those younger than 14 yrs. The most frequent etiologies of the intestinal failure were neoplasia (22%), and mesenteric ischaemia (15%). Tunnelled catheters were used in 63% of the patients. The catheter-related infections were the most frequent complications, with a rate of 1,14 episodes/10(3) days. In 51% of the cases the nutritional support was maintained for more than 2 years. HPN solutions and disposables were supplied by the hospital pharmacy in 76% and 81%, respectively. Up to 50% of the patients had a normal activity level. The most frequent reasons to end HPN treatment were the transition to oral/enteral feeding (41%) and exitus (31%).

CONCLUSIONS

We have observed a mild decrease in the number of HPN patients registered in the period 2004-2005, probably related to the change of the registry. The characteristics of the patients are similar to previous years. We have observed an increase in the septic catheter-related complications in the year 2005.

[Cat-scratch disease. Review of eight adult patients hospitalized for fever or adenopathy]

BACKGROUND

Cat-scratch disease is common among children. Among adults the disease is less often considered in the differential diagnosis of enlarged lymph nodes and fever.

AIM

To report the clinical and laboratory features of eight patients with cat-scratch disease.

MATERIAL AND METHODS

Review of the medical records of eight patients (aged 22 to 57 years, six males) with a serological diagnosis of cat-scratch disease (an IgG titer over 1:256, by immunofluorescence).

RESULTS

Only five patients recalled having had contact with cats. Seven had fever and weight loss. Six had excessive sweating and five had chills. Seven had painfully enlarged lymph nodes mainly in submandibular and axillary regions. All had an increased C reactive protein and six had elevated erythrocyte sedimentation rate. Five had leukocytosis and four an elevated serum lactate dehydrogenase. The disease subsided in all, even in one patient that did not receive antimicrobials.

CONCLUSIONS

Cat-scratch disease should be considered in the differential diagnosis of adult patients with lymph adenitis and fever.

Clinical pharmacokinetics of parenteral dexketoprofen trometamol in healthy subjects

Dexketoprofen trometamol, a highly water-soluble salt of the active enantiomer of rac-ketoprofen, is a nonsteroidal antiinflammatory drug used for pain relief. Two studies were conducted to determine the pharmacokinetics of the drug in healthy subjects following single intravenous (i.v.) and intramuscular (i.m.) doses of dexketoprofen. In the first study, 6 male and 6 female volunteers received 50 mg dexketoprofen (74 mg dexketoprofen trometamol) by i.v. bolus. In the second one, another 6 male and 6 female subjects received 25 mg and 50 mg of dexketoprofen by the i.m. route. Dexketoprofen plasma concentrations were determined by reverse-phase high-performance liquid chromatography (HPLC). No serious adverse events were observed and all volunteers completed the study. The main pharmacokinetic parameters were determined by a noncompartmental approach. Following the i.v. bolus, mean (+/- SEM) area under the curve AUC0-x and clearance (CL) were 9005 +/- 422 ng.h/ml and 0.089 +/- 0.004 l/h/kg. Volumes of distribution Vi and Vss averaged 0.060 +/- 0.006 l/kg and 0.104 +/- 0.003 l/kg. Mean elimination half-life (t1/2e) and MRT were 1.05 +/- 0.04 h and 1.18 +/- 0.05 h. Following single i.m. 25 mg and 50 mg dexketoprofen, a rapid absorption was observed, with tmax values ranging from 0.17 h to 0.75 h. The corresponding Cmax averaged 1851 +/- 182 ng/ml and 3813 +/- 169 ng/ml, and mean AUC0-x were 3033 +/- 193 ng.h/ml and 5878 +/- 228 ng.h/ml, respectively. No significant differences by gender were obtained following both parenteral routes. A dose proportionality in Cmax and AUC0-x was observed. Dexketoprofen pharmacokinetics following i.v. and i.m. routes, together with the availability of a single 2 ml formulation, allows for a potential advantageous rapid switch to the oral formulation when clinically possible.

Ontogeny of the immune system of fish

Information on the ontogeny of the fish immune system is largely restricted to a few species of teleosts (e.g., rainbow trout, catfish, zebrafish, sea bass) and has previously focused on morphological features. However, basic questions including the identification of the first lympho-hematopoietic sites, the origin of T- and B-lymphocytes and the acquisition of full immunological capacities remain to be resolved. We review these three main topics with special emphasis on recent results obtained from the zebrafish, a new experimental model particularly suitable for study of the ontogeny of the immune system because of its rapid development and easy manipulation. This species also provides an easy way of creating mutations that can be detected by various types of screens. In some teleosts (i.e., angelfish) the first blood cells are formed in the yolk sac. In others, such as zebrafish, the first hematopoietic site is an intraembryonic locus, the intermediate cell mass (ICM), whereas in both killifish and rainbow trout the first blood cells appear for a short time in the yolk sac but later the ICM becomes the main hematopoietic area. Erythrocytes and macrophages are the first blood cells to be identified in zebrafish embryos. They occur in the ICM, the duct of Cuvier and the peripheral circulation. Between 24 and 30 hour post-fertilization (hpf) at a temperature of 28 degrees C a few myeloblasts and myelocytes appear between the yolk sac and the body walls, and the ventral region of the tail of 1-2 day-old zebrafish also contains developing blood cells. The thymus, kidney and spleen are the major lymphoid organs of teleosts. The thymus is the first organ to become lymphoid, although earlier the kidney can contain hematopoietic precursors but not lymphocytes. In freshwater, but not in marine, teleosts the spleen is the last organ to acquire that condition. We and other authors have demonstrated an early expression of Rag-1 in the zebrafish thymus that correlates well with the morphological identification of lymphoid cells. On the other hand, the origins and time of appearance of B lymphocytes in teleosts are a matter of discussion and recent results are summarized here. The functioning rather than the mere morphological evidence of lymphocytes determines when the full immunocompetence in fish is attained. Information on the histogenesis of fish lymphoid organs can also be obtained by analysing zebrafish mutants with defects in the development of immune progenitors and/or in the maturation of non-lymphoid stromal elements of the lymphoid organs. The main characteristics of some of these mutants will also be described.

Gene expression in gastric biopsies from patients infected with Helicobacter pylori

BACKGROUND

Helicobacter pylori infection has protean effects on gene expression in the host gastric mucosa, which have been investigated by gene chip analysis in vitro. In this study the effects of H. pylori infection on host gene expression in the gastric antral mucosa in patients were examined.

METHODS

One gastric antral biopsy was obtained from a total of 18 untreated patients undergoing routine endoscopic evaluation of chronic abdominal complaints. Nine patients had histologic evidence of H. pylori infection and 9 age- and sex-matched patients had no histologic evidence of H. pylori infection. A microarray analysis was performed using a gene chip containing 35,000 human expressed sequence tags on RNA extracted from endoscopic, gastric antral biopsies, and average gene expression among infected and uninfected patients was compared.

RESULTS

Underexpressed genes in infected patients' mucosa included gastric intrinsic factor and several metallothionein isoforms. Overexpressed genes in infected patients' mucosa comprised MHC Class II molecules, immunoglobulin and B-cell activation genes, as well as genes known to induce apoptosis. Changes in expression were confirmed for a subset of genes by SYBR green real-time PCR.

CONCLUSIONS

Microarray analysis of antral biopsies from patients with and without H. pylori infection revealed differential expression of metal regulatory, immunity and inflammation-related genes.

Protection against Cocaine Toxicity in Mice by the Dopamine D3/D2 Agonist R-(+)-trans-3,4a,10b-Tetrahydro-4-propyl-2H,5H-[1]benzopyrano[4,3-b]-1,4-oxazin-9-ol [(+)-PD 128,907]

Cocaine abuse is a public health concern with seizures and death being one consequence of overdose. In the present study, dopamine D(3/)D(2) receptor agonists dose dependently and completely prevented the convulsant and lethal effects of cocaine. The D(3)-preferring agonists R-(+)-trans-3,4a,10b-tetrahydro-4-propyl-2H,5H-[1]benzopyrano[4,3-b]-1,4-oxazin-9-ol) [(+)-PD 128,907], (+)-7-hydroxy-dipropylaminotetralin, and the mixed D(3/)D(2) agonists quinpirole and quinelorane were all effective against cocaine toxicity in mice. The anticonvulsant effects of these compounds occurred at doses below those that produced motor impairment as assessed in the inverted screen test. Protection against the convulsant effects of the selective dopamine uptake inhibitor 1-[2-[bis(4-fluorophenyl)methoxy] ethyl]-4-[3-phenyl-propyl]piperazine (GBR 12909) was also conferred by (+)-PD 128,907. The possible selectivity of the effects of (+)-PD 128,907 (3 mg/kg) for these dopaminergic compounds was demonstrated by its general lack of protective efficacy against a host of convulsants acting through other neural mechanisms [pentylenetetrazol, (+)-bicuculline, and picrotoxin, 4-aminopyridine, and t-butylbiclyclophosphoorothionate, N-methyl-d-aspartate, kainate, pilocarpine, nicotine, strychnine, aminophylline, threshold electric shock, and 6-Hz electrical stimulation]. Direct and correlational evidence suggests that these effects were mediated by D(3) receptors. Protection was stereospecific and reversible by an antagonist of D(3) receptors [3-[4[1-(4-[2[4-(3-diethyamino-propoxy)-phenyl]-benzoimidazol-l-yl]-butyl)-1H-benzoimidazol-2-yl]-phenoxy]-propyl)-diethyl-amine; PD 58491] but not D(2) receptors [3[[4-(4-chlorophenyl)-4 hydroxypipeidin-1-yl]methyl-1H-indole; L-741,626]. Anticonvulsant potencies were positively associated with potencies in a functional assay of D(3) but not D(2) receptor function. Together, these findings suggest that the prevention of cocaine convulsions and lethality by (+)-PD 128,907 may be due to D(3) receptor-mediated events.

D(3) receptor ligands modulate extracellular dopamine clearance in the nucleus accumbens

An involvement of the D(3) dopamine receptor in the regulation of extracellular dopamine has been suggested. However, the mechanisms mediating this effect are unclear. We have used the technique of no net flux microdialysis under transient conditions to examine the influence of the D(3) -preferring agonist (+)-PD128907 upon extracellular dopamine levels in the nucleus accumbens of the mouse. (+)-PD 128907 (0.1 mg/kg intraperitoneally) significantly decreased extracellular dopamine. This decrease was associated with a marked increase in the extraction fraction, which suggests an increase in dopamine clearance. The ability of D(3) -preferring compounds to modulate dopamine uptake was investigated in vitro using rotating disk electrode voltammetry. (+)-PD 128907 (10 nm) significantly increased the initial clearance rate of 3 microm dopamine in rat nucleus accumbens tissue suspensions. Kinetic analysis revealed no change in the apparent K (m) of uptake but it showed a 33% increase in V (max). In contrast, the D(3) antagonist GR 103691 (10 nm) significantly decreased dopamine uptake. Consistent with the low levels of D(3) receptors in the dorsal striatum, neither compound affected uptake in tissue suspensions from this brain region. These data indicate that D(3) receptor activation increases dopamine uptake in the nucleus accumbens and suggest that this receptor subtype can regulate extracellular dopamine by modulating the DA transporter activity.

Diabetes in Bolivia

OBJECTIVE

To measure the prevalence of diabetes mellitus (DM), hypertension, obesity, and related risk factors in major cities in Bolivia.

METHODS

A population-based survey was conducted in four Bolivian cities: La Paz, El Alto, Santa Cruz, and Cochabamba. The total sample size was chosen to be 2,948 persons. The overall response rate was 86%, with the rate varying somewhat among the four cities. DM was diagnosed through an oral glucose tolerance test (OGTT) 2 hours after an overload of 75 grams of glucose, using World Health Organization criteria.

RESULTS

The overall prevalence of DM in the four urban areas combined was 7.2% (95% confidence interval (CI): 6.2%-8.3%) and of impaired glucose tolerance (IGT) was 7.8%. A total of 73.1% (95% CI: 65.0%-81.0%) of those previously diagnosed with DM and 73.7% (95% CI: 61.0%-86.4%) of newly diagnosed cases were overweight, according to measurements of body mass index. Hypertension was found in 36.5% (95% CI: 27.6%-45.5%) of known diabetics and in 36.6% (95% CI: 23.0%-50.1%) of newly diagnosed cases, compared to only 15.9% (95% CI: 14.3%-17.5%) among people without DM. The disease was most common among older persons and those with little education.

CONCLUSIONS

Diabetes is a genuine public health problem in Bolivia. Further, the high prevalence of IGT that was found suggests that diabetes prevalence will increase in the near future in the country unless prevention strategies are implemented.

Selective D3 receptor agonist effects of (+)-PD 128907 on dialysate dopamine at low doses

An involvement of the D3 dopamine receptor in the modulation of extracellular dopamine concentrations is suggested by pharmacological studies. However, recent studies using D3 receptor knock out mice indicated that several functions previously attributed to the D3 receptor are mediated by other receptor types. In the present study, we used the no-net flux microdialysis technique to characterize: (i) basal dopamine dynamics in the ventral striatum of D3 knock out and wild type mice and (ii) the effects of the putative D3-receptor selective agonist (+)-PD 128907. Neither the extracellular dopamine concentration nor the in vivo extraction fraction, an indirect measure of basal dopamine uptake, differed between D3 knock out and wild type mice. Moreover, no differences in potassium (60 mM) or cocaine (5 or 20 mg/kg i.p.) evoked dopamine concentrations were detected between the two genotypes. However, intra-striatal or systemic administration of doses of (+)-PD 128907 that failed to modify dopamine concentrations in knock out mice significantly decreased dialysate dopamine concentrations in the wild type. Comparison of the concentration-response curve for (+)-PD 128907 revealed IC(25) values of 61 and 1327 nM in wild type and knock out mice, respectively, after intra-striatal infusions. Similar differences were obtained after systemic administration of the D3 preferring agonist (IC(25) 0.05 and 0.44 mg/kg i.p. in wild type and knock out mice, respectively). We conclude that the activation of the D3 receptor decreases extracellular dopamine levels and that, at sufficiently low doses, the effects of (+)-PD 128907 on extracellular dopamine are selectively mediated by the D3 receptor.