EASE OF HANDLING AND CLINICAL EFFICACY OF FLUTICASONE PROPIONATE ACCUHALER/DISKUS™ INHALER COMPARED WITH THE TURBOHALER™ INHALER IN PAEDIATRIC PATIENTS

A total of 323 children aged 4-11 years who were receiving, or had symptoms indicating a clinical requirement for, inhaled corticosteroid at a daily dose of 400 μg budesonide (BUD) or beclomethasone dipropionate (BDP), or 200 μg fluticasone propionate (FP), were randomised into this multicentre, open-label, parallel group study. Patients received either FP 100 μg b.d. administered via the Accuhaler/Diskus inhaler (n=159) or BUD 200 μg b.d. administered via a Turbohaler inhaler (n=164) for four weeks and recorded daily their morning and evening peak expiratory flow (PEF), asthma symptoms and use of relief medication. Device handling was assessed by a questionnaire, with responses recorded on three- or five-point ordinal scales. The primary efficacy parameter was mean percent predicted morning PEF. The device handling results showed the Accuhaler/Diskus inhaler was rated more favourably than the Turbohaler inhaler in terms of ease of correct inhaler use, ease of telling how many doses were left, ease of knowing whether a dose had been inhaled and overall liking of the device. More patients in the Accuhaler/Diskus group (85%) than in the Turbohaler group (58%) said they would be happy to receive the same device again, while 8% and 25% respectively said they would not be happy to be given it again. In addition, the change from baseline to week 4 of treatment in mean percent predicted morning PEF was greater in the FP Accuhaler/Diskus group, indicating that FP 200 μg daily via Accuhaler/Diskus inhaler is at least as clinically effective as BUD 400 μg daily via the Turbohaler inhaler.     

The hypocretin–orexin system regulates cocaine self‐administration via actions on the mesolimbic dopamine system

Recent evidence suggests that the hypocretin–orexin system participates in the regulation of reinforcement processes. The current studies examined the extent to which hypocretin neurotransmission regulates behavioral and neurochemical responses to cocaine, and behavioral responses to food reinforcement. These studies used a combination of fixed ratio, discrete trials, progressive ratio and threshold self‐administration procedures to assess whether the hypocretin 1 receptor antagonist, SB‐334867, reduces cocaine self‐administration in rats. Progressive ratio sucrose self‐administration procedures were also used to assess the extent to which SB‐334867 reduces responding to a natural reinforcer in food‐restricted and food‐sated rats. Additionally, these studies used microdialysis and in vivo voltammetry in rats to examine whether SB‐334867 attenuates the effects of cocaine on dopamine signaling within the nucleus accumbens core. Furthermore, in vitro voltammetry was used to examine whether hypocretin knockout mice display attenuated dopamine responses to cocaine. Results indicate that when SB‐334867 was administered peripherally or within the ventral tegmental area, it reduced the motivation to self‐administer cocaine and attenuated cocaine‐induced enhancement of dopamine signaling. SB‐334867 also reduced the motivation to self‐administer sucrose in food‐sated but not food‐restricted rats. Finally, hypocretin knockout mice displayed altered baseline dopamine signaling and reduced dopamine responses to cocaine. Combined, these studies suggest that hypocretin neurotransmission participates in reinforcement processes, likely through modulation of the mesolimbic dopamine system. Additionally, the current observations suggest that the hypocretin system may provide a target for pharmacotherapies to treat cocaine addiction.     

Real-time voltammetric detection of cocaine-induced dopamine changes in the striatum of freely moving mice

In the present voltammetric study, we have characterized cocaine-induced changes in evoked dopamine release and uptake in the striatum of freely moving mice in real time. Cocaine induced marked dopamine uptake inhibition measured as apparent K_m changes, producing a maximal effect 20 min following a single injection (15 mg/kg, i.p.). Changes in uptake were paralleled by increases in evoked dopamine release per stimulus pulse, revealing a high correlation between these two parameters following cocaine administration. This initial characterization of cocaine effects on striatal dopamine transmission in the commonly used C57BL/6 mouse strain provides a basis for future voltammetric studies using genetic mouse models.     

Epstein Barr virus latent membrane protein-1 in Hodgkin's lymphoma in Nigerians

Background

The burden of lymphomas on the health care system in Nigeria is enormous. Correct diagnosis and identification of aetiological factor are important steps in reducing this burden.

Methods

Eight cases diagnosed as HL within a period of six years at the Obafemi Awolowo University teaching Hospital, Ile-Ife, Nigeria by haematoxylin and eosin (Hand E) only were immunophenotyped using the indirect immunoperoxidase method. Epstein-Barr virus latent membrane protein-1 (LMP-1), CD15 and CD30 immunohistochemistry was also performed. The clinical characteristics of each patient were documented.

Objectives

To document the frequency of involvement of Epstein-Barr virus in cases of HL seen in a university hospital in Nigeria.

Results

Out of the eight cases diagnosed by H&E as HL immunophenotyping showed only five were HL. The rest were non-Hodgkin''s lymphoma (2 diffuse large B-cell and 1 null cell ALCL). All were cases of classical HL with 60% being of the mixed cellularity (MC) subtype. There were 2 males and 3 females with ages ranging from 7 years to 40 years. All presented with cervical lymphadenopathy and three had splenomegaly in addition. 60% of the tumour was EBV positive, all of the MC subtype. Three patients had chemotherapy. Eventually all were lost to follow-up. There was no case of the nodular lymphocyte predominance variant.

Conclusion

Mixed cellularity is the most common subtype and is the only subtype associated with EBV positivity in this study. Epstein-Barr virus probably plays an important role in the aetiology of HL in Nigerians.Running title: Epstein-Barr virus, Hodgkin''s lymphoma in Nigerians     

Multiple granular cell tumors are an associated feature of LEOPARD syndrome caused by mutation in PTPN11

We report a patient with a clinical and molecular diagnosis of LEOPARD syndrome (LS) associated with multiple granular cell tumors (MGCT). Bidirectional sequencing of exons 7, 12, and 13 of the PTPN11 gene revealed the T468M missense mutation in exon 12. This mutation has been previously reported in patients with LS. To our knowledge, this is the first report of MGCT associated with molecularly characterized LS and provides the first molecular evidence linking granular cell tumors (GCT) to the Ras/mitogen-activated protein (MAP) kinase pathway. We propose that MGCT can be associated with LS. Analysis of GCT from this case tested negatively for loss of heterozygosity (LOH) at the PTPN11 and NF1 loci and did not show deletions of the PTEN gene. The absence of LOH of PTPN11 supports published functional data that T468M is a dominant-negative mutation.     

Desensitization of endothelial P2Y1 receptors by PKC-dependent mechanisms in pressurized rat small mesenteric arteries

Background and purpose:

Extracellular nucleotides play a crucial role in the regulation of vascular tone and blood flow. Stimulation of endothelial cell P2Y1 receptors evokes concentration-dependent full dilatation of resistance arteries. However, this GPCR can desensitize upon prolonged exposure to the agonist. Our aim was to determine the extent and nature of P2Y1 desensitization in isolated and pressurized rat small mesenteric arteries.

Experimental approach:

The non-hydrolyzable selective P2Y1 agonist ADPβS (3 µM) was perfused through the lumen of arteries pressurized to 70 mmHg. Changes in arterial diameter and endothelial cell [Ca²⁺]_i were obtained in the presence and absence of inhibitors of protein kinase C (PKC).

Key results:

ADPβS evoked rapid dilatation to the maximum arterial diameter but faded over time to a much-reduced plateau closer to 35% dilatation. This appeared to be due to desensitization of the P2Y1 receptor, as subsequent endothelium-dependent dilatation to acetylcholine (1 µM) remained unaffected. Luminal treatment with the PKC inhibitors BIS-I (1 µM) or BIS-VIII (1 µM) tended to augment concentration-dependent dilatation to ADPβS (0.1–3 µM) and prevented desensitization. Another PKC inhibitor, Gö 6976 (1 µM), was less effective in preventing desensitization. Measurements of endothelial cell [Ca²⁺]_i in pressurized arteries confirmed the P2Y1 receptor but not M₃ muscarinic receptor desensitization.

Conclusions and implications:

These data demonstrate for the first time the involvement of PKC in the desensitization of endothelial P2Y1 receptors in pressurized rat mesenteric arteries, which may have important implications in the control of blood flow by circulating nucleotides.     

Inhibition of oral midazolam clearance by boosting doses of ritonavir,and by 4,4-dimethyl-benziso-(2H)-selenazine (ALT-2074), an experimental catalytic mimic of glutathione oxidase

AIMS

We evaluated whether ‘boosting’ doses of ritonavir can serve as a positive control inhibitor for pharmacokinetic drug–drug interaction studies involving cytochrome P450 3A (CYP3A). The study also determined whether 4,4-dimethyl-benziso-(2H)-selenazine (ALT-2074), an investigational organoselenium compound that acts as a catalytic mimic of glutathione oxidase, inhibits CYP3A metabolism in vivo.

METHODS

Thirteen healthy volunteers received single 3-mg oral doses of midazolam on three occasions: in the control condition, during co-treatment with low-dose ritonavir (three oral doses of 100 mg over 24 h), and during co-treatment with ALT-2074 (three oral doses of 80 mg over 24 h).

RESULTS

Ritonavir increased mean (±SE) total area under the curve (AUC) for midazolam by a factor of 28.4 ± 4.2 (P < 0.001), and reduced oral clearance to 4.2 ± 0.5% of control (P < 0.001). In contrast, ALT-2074 increased midazolam AUC by 1.25 ± 0.11 (P < 0.05), and reduced oral clearance to 88 ± 8% of control.

CONCLUSIONS

Low-dose ritonavir produces extensive CYP3A inhibition exceeding that of ketoconazole (typically 10- to 15-fold midazolam AUC enhancement), and is a suitable positive control index inhibitor for drug–drug interaction studies. ALT-2074 inhibits CYP3A metabolism to a small degree that is of uncertain clinical importance.     

Effects of chronic alcohol exposure on dopamine uptake in rat nucleus accumbens and caudate putamen

Rationale

Existing data strongly suggest that alcohol affects dopamine (DA) neurotransmission in the brain. However, many questions remain about the effects of alcohol on the delicate equilibrium between such neurochemical processes as DA release and uptake. Dysregulation of these processes in the mesolimbic and nigrostriatal systems after chronic alcohol ingestion could be a neuroadaptation contributing to dependence.

Objectives

In the present study, we have employed an alcohol vapor inhalation model to characterize the effects of chronic alcohol exposure on DA dynamics in rat nucleus accumbens (NAc) and caudate putamen (CP) using fast-scan cyclic voltammetry (FSCV) in brain slices. This method provides a unique view of real-time, spatially resolved changes in DA concentration.

Results

We found that chronic alcohol exposure enhanced DA uptake rates in rat NAc and CP. These changes would have the effect of down-regulating extracellular DA levels, presumably a compensatory effect related to increased DA release by repeated alcohol exposure. The sensitivity of terminal release-regulating DA autoreceptors was not different in alcohol-exposed rats compared with alcohol-naïve animals.

Conclusions

The DA uptake changes after chronic alcohol exposure documented here using FSCV may be associated with a compensatory response of the DA system aimed at decreasing DA signaling. Alterations in autoreceptor function may require relatively long lasting alcohol exposure.