Progressive-ratio performance maintained by drug infusions: Comparison of cocaine,diethylpropion, chlorphentermine,and fenfluramine

Cocaine, diethylpropion, chlorphentermine, and fenfluramine were compared on a drug-maintained progressive-ratio procedure in baboons. Intravenous infusions of drug were contingent on completion of a fixed-ratio response requirement (fixed number of lever-press responses) with a 3-h time-out period following each infusion. Prior to testing each dose of drug, stable self-infusion performance was first established with 0.4 mg/kg cocaine when the fixed-ratio requirement was 160. Subsequently, a test dose of drug was substituted for the standard dose of cocaine. If the dose of drug maintained a criterion level of self-infusion performance (six or more infusions per day for 2 days), the ratio requirement was systematically increased every day until the breaking point at which the self-infusion performance fell below a criterion level (one or zero infusionsper day). Fenfluramine did not maintain criterion self-infusion performance at any dose tested (0.02–5.0 mg/kg). The dose ranges of the other drugs that maintained maximum breaking points were 1.0–5.6 mg/kg for chlorphentermine, 1.0–3.0 mg/kg for diethylpropion, and 0.1–0.4 mg/kg for cocaine. Within-animal comparison of the maximum breaking points indicated that cocaine maintained the highest breaking points, followed in order by diethylpropion, chlorphentermine, and fenfluramine. The rank ordering of these drugs with the breaking point measure corresponds well with both the results of other animal experiments on measurement of reinforcing efficacy of these drugs and with the clinical information about the human subjective effects and abuse of these drugs.     

CD44 variant expression and estrogen receptor status in breast cancer

To understand the relationship between CD44 gene expressionand an established variable associated with aggressive behaviourin human breast cancer, we have studied apanel of 6 breast cell lines and 40breast tumors selected primarily on the basis ofestrogen receptor (ER) status. CD44s (standard form) mRNAwas assessed by semi-quantitative RT-PCR, and CD44 variantsincorporating exon v7 or v10 were studied byRT-PCR and Southern blot. While CD44 expression wasnot influenced by estrogen in ER+ve MCF-7 cells,CD44s expression was slightly higher (up to 2fold) in ER–ve cells but there was amarked decrease in the range of CD44 variantsincorporating exons v7 or v10. In microdissected tumors,the levels of CD44s showed no correlation withER status but the pattern of expression oflarger forms of CD44 incorporating variant exons v7and v10 was significantly different (p=0.005and p=0.015, respectively) between ER+ve andER–ve tumors, reflecting the pattern seen in thecell lines. These findings suggest that the profileof CD44 expression in breast cancer may reflectcellular differentiation as indicated by the ER phenotype.The influence of these differences in CD44 expressionon the increased metastatic potential of ER negativebreast cancer remains to be determined.     

Sequential vapour ablation of adjacent segments in canine lung

Introduction: Vapour ablation is used to create lung volume reduction for emphysema patients to improve lung function and quality of life. This study characterises effects of vapour ablation treatment in lung segments within a lobe that are adjacent to lung segments previously treated with vapour in a healthy canine model. Because emphysema is a progressive disease, subsequent treatments could offer continued benefit to the patient. Method: Six healthy canines were treated with vapour at 8.5?cal/g in one upper lobe segment. After a 4-week healing period, the adjacent segment was treated. After a second 4-week healing period, necropsy was performed and the tissue inspected. Clinical effects were monitored during each healing period. Results: Each treatment was well tolerated and no significant abnormalities were observed during the healing phases, including death, pneumothorax, or major decline in health status. Animal health, oxygenation changes, pathology, and airway changes were monitored during the study. Analysis of these end points showed no difference in changes after treatment 2 as compared to changes after treatment 1. Conclusion: In this model, there was no evidence of increased or different clinical observations after a second adjacent vapour ablation. It was not possible to differentiate between the clinical effects of treatment 1 and the clinical effects of treatment 2. These results support investigation of sequential adjacent segmental vapour treatments in humans.     

Mycobacterium abscessus Complex – a Particular Challenge in the Setting of Lung Transplantation

Mycobacterium abscessus complex is an emerging pathogen in lung transplant candidates and recipients. M. abscessus complex is widespread in the environment and can cause pulmonary, skin and soft tissue, and disseminated infection, particularly in lung transplant recipients. It is innately resistant to many antibiotics making it difficult to treat. Herein we describe the epidemiology, clinical manifestations, diagnosis and treatment of M. abscessus with an emphasis on lung transplant candidates and recipients. We also outline the areas where data are lacking and the areas where further research is urgently needed.     

Herpes simplex virus infection of the adult lower respiratory tract

We have reported six adult patients with HSV infection of the lower respiratory tract diagnosed ante-mortem, and have reviewed the literature on this subject. An attempt has been made to define the natural history of the infection, and suggestions have been made regarding diagnosis and treatment. HSV can infect the lower respiratory tract in immunologically normal patients, as well as the immunocompromised host. Many patients have been burned, or intubated, or have other reasons for squamous metaplasia of the respiratory epithelium. The pathogenesis in many cases is an extension or aspiration of oropharyngeal HSV, but there is a suggestion that some cases may be hematogenously spread. The diagnosis of the site and presence of HSV infection should be based initially on cytologic findings, histologic findings, or both. Viral cultures or immunofluorescent or immunoperoxidase labeling can be used to confirm the cytologic and histologic diagnoses. Bronchoscopy is valuable for visualizing ulcerations or membranes in the respiratory tract, and for improving the sensitivity and specificity of the cytologic diagnosis. Because the process is most often focused in the tracheobronchial tree, percutaneous needle biopsy and open lung biopsy may be less sensitive than bronchoscopy. Standard serologic tests are, in general, not helpful diagnostically. They can help verify that a recent HSV infection has occurred, but do not differentiate between primary and recurrent infection, and do not help in localizing the site of infection. However, paired complement fixation or neutralizing antibody titers may be useful prognostically. If the titers do not rise in the presence of a documented HSV lower respiratory tract infection, the outcome is more likely to be fatal. The respiratory epithelium from the oral mucosa to the alveoli can be infected with HSV. The manifestations can range from a few scattered ulcers in the trachea to a severe ulcerative process resulting in an obstructing, inflammatory tracheobronchial membrane. Focal or diffuse pneumonia can also occur. No specific treatment for the illness can be recommended at this time. There is no evidence that currently available antiviral therapy is effective. The outcome of the illness seems to be largely dependent on the immunologic status of the host, complicating superinfections, and the progression of the underlying disease.     

Genetic polymorphism PC-1 K121Q and ethnic susceptibility to insulin resistance

Genetic susceptibility may be responsible for high prevalence of insulin resistance in Asian Indians. This study was carried out in samples of local Asian Indians and Caucasians to determine whether plasma cell membrane glycoprotein (PC)-1 K121Q and insulin receptor substrate-1 (IRS-1) G972A polymorphisms contribute significantly to susceptibility to insulin resistance in Asian Indians. The frequency of carrying at least one copy of the PC-1 121Q variant in Asian Indians was significantly higher than that in Caucasians (P = 0.01), but the frequency was similar for IRS-1 972A (6% and 7%). A significantly higher insulin area under the curve during oral glucose tolerance testing (P < 0.0001) and lower insulin sensitivity during hyperinsulinemic-euglycemic clamps (P = 0.04) were found in Asian Indians with PC-1 121Q variant compared with Asian Indians with wild-type PC-1 and with Caucasians with or without the polymorphism. IRS-1 972A was not associated with any change in insulin sensitivity. We conclude that the PC-1 K121Q polymorphism associates with primary insulin resistance in migrant Asian Indians. A relatively high frequency of this polymorphism thus may be one factor contributing to insulin resistance susceptibility in Asian Indians. This finding indicates the need for expanded studies on the association between PC-1 K121Q and insulin resistance in a representative sample of the Asian Indian population.     

Rehabilitation after total joint replacement: a scoping study

Purpose: The evidence supporting rehabilitation after joint replacement, while vast, is of variable quality making it difficult for clinicians to apply the best evidence to their practice. We aimed to map key issues for rehabilitation following joint replacement, highlighting potential avenues for new research.

Materials and methods: We conducted a scoping study including research published between January 2013 and December 2016, evaluating effectiveness of rehabilitation following hip and knee total joint replacement. We reviewed this work in the context of outcomes described from previously published research.

Results: Thirty individual studies and seven systematic reviews were included, with most research examining the effectiveness of physiotherapy-based exercise rehabilitation after total knee replacement using randomized control trial methods. Rehabilitation after hip and knee replacement whether carried out at the clinic or monitored at home, appears beneficial but type, intensity and duration of interventions were not consistently associated with outcomes. The burden of comorbidities rather than specific rehabilitation approach may better predict rehabilitation outcome. Monitoring of recovery and therapeutic attention appear important but little is known about optimal levels and methods required to maximize outcomes.

Conclusions: More work exploring the role of comorbidities and key components of therapeutic attention and the therapy relationship, using a wider range of study methods may help to advance the field.

• Implications for Rehabilitation

• Physiotherapy-based exercise rehabilitation after total hip replacement and total knee replacement, whether carried out at the clinic or monitored at home, appears beneficial.

• Type, intensity, and duration of interventions do not appear consistently associated with outcomes.

• Monitoring a patient’s recovery appears to be an important component. The available research provides limited guidance regarding optimal levels of monitoring needed to achieve gains following hip and knee replacement and more work is required to clarify these aspects.

• The burden of comorbidities appears to better predict outcomes regardless of rehabilitation approach.