Acute systemic blockade of D2 receptors does not accelerate the extinction of cocaine-associated place preference.

Facilitation of extinction can be used as a therapeutic tool in treatment of both post-traumatic stress disorder and drug addiction. The present study examined whether the blockade of D2 receptors before each extinction trial would accelerate the extinction of cocaine-induced place preference. Male Wistar rats were initially conditioned and tested for a cocaine-associated place-preference (20 mg/kg). On the following day after the initial test, the animals were submitted to extinction training. This training consisted of daily sessions in which the subjects were alternatively confined during 30 min in the saline and cocaine-associated environment. However, 30 min before each extinction trial the animals received a systemic injection of D2 antagonist sulpiride. While one group was treated with a dose of 50 mg/kg (ip), the other group was treated with a dose of 100 mg/kg. An additional control group received injections of saline during extinction trials. Twenty-four hours after the last extinction trial, the animals were tested again for their preferences to cocaine and saline associated environments. Since one round of extinction trial was not sufficient to produce extinction of cocaine associated place preference, the animals were submitted to a second cycle of extinction trials and test. The systemic administration of the two doses of sulpiride (50 and 100 mg/kg) 30 min before each conditioning did not enhance the extinction of cocaine-associated place preference. This finding suggests that the D2 receptors are not involved in a acute protocol of extinction of cocaine-induced place preference.

Modulation by simvastatin of iberiotoxin-sensitive, Ca2+-activated K+ channels of porcine coronary artery smooth muscle cells.

BACKGROUND AND PURPOSE: Statins (3-hydroxy-3-methyl-glutaryl coenzyme A (HMG CoA) reductase inhibitors) have been demonstrated to reduce cardiovascular mortality. It is unclear how the expression level of HMG CoA reductase in cardiovascular tissues compares with that in cells derived from the liver. We hypothesized that this enzyme exists in different cardiovascular tissues, and simvastatin modulates the vascular iberiotoxin-sensitive Ca2+-activated K(+) (BK(Ca)) channels. EXPERIMENTAL APPROACHES: Expression of HMG CoA reductase in different cardiovascular preparations was measured. Effects of simvastatin on BK(Ca) channel gatings of porcine coronary artery smooth muscle cells were evaluated. KEY RESULTS: Western immunoblots revealed the biochemical existence of HMG CoA reductase in human cardiovascular tissues and porcine coronary artery. In porcine coronary artery smooth muscle cells, extracellular simvastatin (1, 3 and 10 microM) (hydrophobic), but not simvastatin Na+ (hydrophilic), inhibited the BK(Ca) channels with a minimal recovery upon washout. Isopimaric acid (10 microM)-mediated enhancement of the BK(Ca) amplitude was reversed by external simvastatin. Simvastatin Na+ (10 microM, applied internally), markedly attenuated isopimaric acid (10 microM)-induced enhancement of the BK(Ca) amplitude. Reduced glutathione (5 mM; in the pipette solution) abolished simvastatin -elicited inhibition. Mevalonolactone (500 microM) and geranylgeranyl pyrophosphate (20 microM) only prevented simvastatin (1 and 3 microM)-induced responses. simvastatin (10 microM ) caused a rottlerin (1 microM)-sensitive (cycloheximide (10 microM)-insensitive) increase of PKC-delta protein expression. CONCLUSIONS AND IMPLICATIONS: Our results demonstrated the biochemical presence of HMG CoA reductase in different cardiovascular tissues, and that simvastatin inhibited the BK(Ca) channels of the arterial smooth muscle cells through multiple intracellular pathways.

Protein synthesis inhibition in the basolateral amygdala following retrieval does not impair expression of morphine-associated conditioned place preference.

Conditioned place preference is an animal model used to evaluate the affective properties of natural rewards and drugs of abuse. This animal model is a kind of classical conditioning that depends on learning and memory. The basolateral amygdala (BLA) plays an important role in the consolidation and extinction of memory for this task. However, there is a lack of evidence demonstrating protein synthesis dependent reconsolidation following retrieval in conditioned animals. In other words, is it possible to observe morphine-associated place preference if recall of this preference is disrupted? Accordingly, we investigated this hypothesis by BLA infusion of protein synthesis inhibitor, anisomycin, immediately after retrieval (test) in conditioned place preference paradigm. In the first experiment, the conditioned animals were exposed to the two sides of the apparatus for 15 min in a drug-free state during retrieval. In the second experiment, the animals received an injection of morphine (7.5 mg/kg, i.p.) and immediately after, they were exposed to the two sides of the apparatus for 15 min. Finally in the third experiment, after habituation and training in the conditioned place preference task, the animals received an injection of the unconditioned stimulus (morphine, i.p.; 7.5 mg/kg) followed by confinement for 10 min in the morphine-paired compartment (conditioned stimulus) during memory retrieval. For the three experiments the animals were subsequently exposed in a free-drug state to the two sides of the apparatus for the retest. Our results show that the protein synthesis inhibition in all of these experimental designs had no effect on conditioned place preference memory under conditions that would initiate reconsolidation, suggesting that if reconsolidation of a conditioned place preference task exists it is not mediated by protein synthesis in basolateral amygdala. The effect of anisomycin on consolidation of contextual fear conditioning was also investigated as a positive control to assure that the negative results were not due to methodological problems. Using the same dose of anisomycin (62.5 microg/1 microl) in morphine-associated place preference procedures, we have found that this anisomycin dose blocks the consolidation of contextual fear memory, ruling out the possibility that these negative results can be attributed to methodological problem of some sort.

Video assisted thoracic surgery in the management of spontaneous pneumothorax: the current status.

Over the past decade, video assisted thoracic surgery (VATS) has changed the way spontaneous pneumothorax (SP) is managed. Benefits of VATS include less postoperative pain, shorter hospital stay, and attenuated postoperative inflammatory response are evident compared with open thoracic procedures. Furthermore, the increasing acceptance by patients and referring physicians is testament to its success. Recent studies and the authors decade of experience in management of SP by VATS show that it is quick, safe, and effective, with recurrence rates generally comparable to open procedures, with some exceptions. However, selecting the correct procedure and patient, as well as knowing the limitations of the surgeons and techniques are paramount for success. Even to this day, there are considerable variations in the treatment of SP and large scale controlled studies are needed to better define timing of surgery and the role of the different procedures in the treatment and prevention of SP.

A comparative study of morphine treatment regimen prior to mating and during late pregnancy.

Pre-mating treatment of female rats with morphine may have long-term effects. In this study, we analyzed the effects of two types of morphine sulfate pre-treatment: during pre-mating (5.0 mg/kg on alternate days for a total of seven doses) and during pregnancy (3.5 mg/(kgday) for 5 days starting on day 17 of pregnancy during early lactation. In order to evaluate possible morphine-induced behavioral changes, dams were tested for maternal behavior and locomotor activity during early lactation, and striatal and hypothalamic concentrations of dopamine and their metabolites and serum levels of corticosterone were measured. Maternal behavior was disrupted only in animals treated with morphine sulfate during pregnancy and challenged acutely (1.5 mg/kg) during lactation. Pre-mating treatment with morphine sulfate-induced changes in responses with increased locomotor activity, striatal dopamine turnover and serum corticosterone levels. None of these parameters were affected by morphine sulfate pre-treatment during late pregnancy. These data suggest that morphine has specific long-term and sometimes addictive-like effects on actively reproductive female animals that vary with the pre-treatment period, late pregnancy being particularly sensitive for effects on maternal behavior.

Validation of peptide mapping with electrospray mass spectrometry for recombinant proteins of biopharmaceutical interest and its applications as an identity test and a characterization tool.

In this paper, the steps required to validate a liquid chromatography peptide mapping method with mass spectrometric detection (LC-MS) for use as an identity test and characterization tool are presented. All aspects of peptide mapping are evaluated and optimized, including protein sample preparation (protein reduction, alkylation and enzymatic digestion), high performance liquid chromatography (HPLC) separation of the resulting peptides, and the use of a mass spectrometric detection. In addition, the validation of a single quadruple MS detector is described and the implementation of on-line electrospray ionization MS (ESI-MS) as an adjunct detector to support the investigation of peak differences is presented. Applications of peptide mapping with tandem MS using an electrospray ion-trap instrument throughout the biopharmaceutical product development cycle are discussed, including assessing protein product heterogeneity derived from post-translational modifications (e.g. multiple N- or C-termini, deamidation, oxidation and glycosylation) and protein degradation.

Pulmonary ischaemia-reperfusion injury: role of apoptosis.

The central role of lung ischaemia-reperfusion injury in pulmonary dysfunction after cardiac surgery, particularly thoracic organ transplantation, has been well recognised. Lung tissue necrosis after prolonged ischaemia is known to worsen lung function, which was believed to be due largely to adjacent tissue inflammation. Recent studies suggest that lung apoptosis following ischaemia-reperfusion could be equally important in the development of post-operative lung dysfunction. The current literature on the mechanism and pathways involved in pulmonary dysfunction and, in particular, its relationship with apoptosis after lung ischaemia-reperfusion is briefly reviewed here. A better understanding of lung apoptosis, as well as the upstream pathways, may help in the development of therapeutic strategies that could benefit patients undergoing cardiac and lung transplantation.

Current indications and results of VATS in the evaluation and management of hemodynamically stable thoracic injuries.

OBJECTIVE: Thoracic injuries are among the most severe forms of trauma and also a leading cause of morbidity and mortality. Video Assisted Thoracic Surgery (VATS) has recently provided an alternative method to simultaneously diagnose and manage patients sustaining chest injuries. We analyze our experience with VATS in the setting of thoracic trauma detailing indications for exploration, procedures performed and results of surgery. METHODS: A 6-year single institution review of patients undergoing VATS due to injuries sustained from both blunt and penetrating chest trauma at a Level I trauma center and university teaching hospital. Comparisons were made between groups of blunt and penetrating trauma as to Injury Severity Score (ISS), presence of extra-thoracic injuries, initial thoracostomy drainage and length of postoperative stay. RESULTS: VATS was successfully performed in 19 consecutive patients without conversion to thoracotomy. Indications for exploration included acute hemorrhage, retained hemothorax, suspected diaphragmatic injuries (DI), suspected cardiac injury, intra-thoracic foreign body, persistent airleak and chronic empyema. Procedures performed consisted of evacuation of retained hemothorax, hemostasis of intra-thoracic bleeders, repair of DI, wedge lung resections and decortication. Mean postoperative length of stay was 5.86 days. There were no morbidities. One patient with severe intra-abdominal injuries expired on the first postoperative day. CONCLUSION: In hemodynamically stable patients with thoracic injuries, VATS provides an accurate assessment of intra-thoracic organ injury and can be utilized to definitively and effectively manage injuries sustained as a result of blunt or penetrating thoracic trauma. VATS should be used with caution in patients sustaining severe and life threatening intra-abdominal injuries.

Distinct patterns of genetic alterations in adenocarcinoma and squamous cell carcinoma of the lung.

Squamous cell carcinoma (SqC) and adenocarcinoma (AdC) are the two most common subtypes of non-small cell lung cancer (NSCLC). Cumulative information suggests that the SqC and AdC subtypes progress through different carcinogenic pathways, but the genetic aberrations promoting such differences remain unclear. Here we have assessed the overall genomic imbalances and structural abnormalities in SqC and AdC. By parallel analyses with comparative genomic hybridisation (CGH) on tumorous lung tissues and spectral karyotyping (SKY) on short-term cultured primary tumours, genome-wide characterisation was carried out on 69 NSCLC (35 SqC, 34 AdC). Molecular cytogenetic characterisation indicated common and distinct genetic changes in SqC and AdC. Common events of +1q21-q24, +5p15-p14, and +8q22-q24.1, and -17p13-p12 were found in both groups, although hierarchical clustering simulation on CGH findings depicted +2p13-p11.2, +3q25-q29, +9q13-q34, +12p, +12q12-q15 and +17q21, and -8p in preferential association with SqC pathogenesis (P<0.05). Corresponding SKY analysis suggested that these changes occur in simple and complex rearrangements, and further indicated the clonal presence of translocation partners leading to chromosomal over-representations. These recurring rearrangements involved chromosome pairs of t(1;13), t(1;15), t(7;8), t(8;15), t(8;9), t(2;17) and t(15;20). Of particular interest was the finding that the t(8;12) translocation partner was exclusive to AdC. The combined application of SKY and CGH has thus uncovered the genome-wide chromosomal aberrations in NSCLC. Specific chromosomal imbalances and translocation partners found in SqC and AdC have highlighted regions for further molecular investigation into gene(s) that may hold importance in the carcinogenesis of NSCLC.

Thiopurine methyltransferase activity and the use of azathioprine in inflammatory bowel disease.

BACKGROUND: Azathioprine therapy is discontinued in one-third of patients with inflammatory bowel disease because of toxicity or a lack of clinical response. Patients with thiopurine methyltransferase (TPMT) deficiency are intolerant to azathioprine, whilst carriers are at increased risk of side-effects. AIM: To evaluate the importance of TPMT activity in the management of azathioprine therapy in inflammatory bowel disease. METHODS: Clinical response, adverse effects and haematological parameters were determined and correlated with TPMT enzyme activity and genotype in 106 patients with inflammatory bowel disease. RESULTS: Ninety-six patients had high TPMT activity, and 10 had intermediate activity. Nineteen patients (18%) were intolerant to azathioprine. Fifteen (16%) of those with high TPMT activity were intolerant, compared with five (50%) with intermediate activity [odds ratio (OR), 5.4; 95% confidence interval (CI), 1.5-19.8]. Complete remission was achieved in 63% of cases, and complete or partial remission in 79%. Interestingly, very high TPMT activity (> 14 units/mL red blood cells) was significantly associated with non-response, irrespective of the time on azathioprine (OR, 0.21; 95% CI, 0.07-0.68). TPMT gene mutations correlated with TPMT activity. CONCLUSIONS: Inflammatory bowel disease patients with intermediate TPMT activity have an increased risk of azathioprine toxicity. Conversely, very high TPMT activity predicts treatment failure. TPMT genotype predicted TPMT phenotype in this study.

Video-assisted thoracic surgery for mediastinal extramedullary haematopoiesis.

Extramedullary haematopoiesis is a rare cause of an intrathoracic mass. We report a case of posterior mediastinal extramedullary haematopoietic mass in a 50-year-old man who presented with non-specific symptoms and a paravertebral mass on chest X-ray. Diagnosis was achieved by using video-assisted thoracic surgery.

Idiopathic localised bladder amyloidosis: rare cause of haematuria.

Idiopathic Localised Bladder Amyloidosis is a rare cause of haematuria and urinary tract symptoms. A review of the literature highlights the varied presentations and the appropriate investigations for this condition, with emphasise on the exclusion of a secondary cause. In addition, the range of treatment options is fully discussed. Our report on a 65-year old gentleman illustrates that a high index of suspicion is required for its diagnosis. Furthermore, conservative management can be an effective strategy in selected patients.

Does external stenting reduce porcine vein-graft occlusion via an action on vascular nerves?

BACKGROUND: Neural reorganization occurs in porcine vein grafts and placement of an external stent reduces graft occlusion. AIM OF THE STUDY: To determine the effect of external stenting on the innervation of porcine vein grafts. METHODS: Saphenous vein into carotid artery grafting (with and without external stents) was performed in 16 pigs. After one and six months, grafts were removed, nerves were counted, and neointima was assessed. RESULTS: In vein graft compared to ungrafted vein, there was a significant (p < 0.05) decrease in medial perivascular nerves, but a dramatic increase in paravascular nerves in the adventitia (p < 0.05). In stented vein grafts there was also a reduction of perivascular nerves and the paravascular nerve proliferation observed in vein grafts at one month was inhibited (p < 0.05). Neointima formation and the appearance of large paravascular nerve bundles in the adventitia of vein grafts were abolished by external stenting. CONCLUSIONS: Neural reorganization plays a role in vein-graft failure, possibly through the local release of mitogens; the prevention of this reorganization contributes to the inhibitory effect of the external stent on neointima formation.