Intraoperative contralateral pneumothorax during single-lung transplantation

Contralateral intraoperative tension pneumothorax is a rare complication of thoracic surgical procedures. Here we present three cases of tension pneumothorax that developed during single-lung transplantation for emphysema and pulmonary fibrosis. To the best of our knowledge, this is only the second report of contralateral intraoperative tension pneumothorax during single-lung transplantation. A high index of clinical suspicion is required for the detection of this potentially catastrophic complication.     

Esophageal perforation after catheterization of the subclavian vein

The insertion of a central venous catheter (CVC) via the subclavian vein is often associated with complications. We report a case in which a patient suffered an esophageal lesion with severe bleeding and a pneumothorax with mediastinal shift induced by the insertion of the dilator of a CVC. The pneumothorax had to be treated immediately by pleural drainage, and the esophageal lesion was successfully corrected by means of an endoclip. The patient survived the complication. However, he died 1 week later from multiple organ failure not associated with the CVC insertion.     

Primary care physicians' attitudes related to cognition enhancers in early dementia: a representative eight-year follow-up study in Lower Saxony, Germany

OBJECTIVE: By means of a representative follow-up survey, we investigated changes in family physicians' (FPs) attitudes towards cognition enhancers in early dementia during 1993 and 2001. METHODS: One hundred and twenty-two FPs (response rate 71.8%) in Lower Saxony, Germany, were randomly assigned to one of two written case samples presenting a patient with cognitive decline suggestive of early Alzheimer's disease (DAT; case A: female patient vs case B: male patient). Using a structured face-to-face interview, they were asked to suggest their potential drug treatment. The results were compared to corresponding data from our previous survey in 1993. RESULTS: FPs' readiness to start antidementia drug treatment decreased from 70.4% in 1993 to 43.4% at follow-up, although underlying DAT was significantly more frequently suggested (11.0% vs 26.2%, p < 0.05). Substances with questionable efficacy such as Piracetame were prescribed less frequently in 2001 whereas evidence-based medication like cholinesterase inhibitors (ChEIs) failed to compensate for this drop. Compared to 1993, when 55.2% of FPs expected no therapeutic impact, at follow-up, 75.4% expected slowdown of disease progression, stabilisation or improvement of symptoms (p < 0.05). CONCLUSIONS: Our results demonstrate a significant decrease of therapeutic nihilism in primary care within eight years. However, in patients with suspicion of DAT, this is not reflected accordingly in potential treatment.     

LRP1 modulates APP trafficking along early compartments of the secretory pathway

The amyloid beta peptide (Aβ) is a central player in Alzheimer's disease (AD) pathology. Aβ liberation depends on APP cleavage by β- and γ-secretases. The low density lipoprotein receptor related protein 1 (LRP1) was shown to mediate APP processing at multiple steps. Newly synthesized LRP1 can interact with APP, implying an interaction between these two proteins early in the secretory pathway. We wanted to investigate whether LRP1 mediates APP trafficking along the secretory pathway, and, if so, whether it affects APP processing. Indeed, the early trafficking of APP within the secretory pathway is strongly influenced by its interaction with the C-terminal domain of LRP1. The LRP1-construct expressing an ER-retention motif, LRP-CT KKAA, had the capacity to retard APP traffic to early secretory compartments. In addition, we provide evidence that APP metabolism occurs in close conjunction with LRP1 trafficking, highlighting a new role of lipoprotein receptors in neurodegenerative diseases.     

Prevalence of enteric protozoa in human immunodeficiency virus (HIV)-positive and HIV-negative men who have sex with men from Sydney, Australia

A prospective, comparative study of the prevalence of enteric protozoa was determined among human immunodeficiency virus (HIV)- positive and HIV-negative men who have sex with men (MSM) in Sydney, Australia. A total of 1,868 patients submitted stool specimens; 1,246 were from MSM (628 HIV positive and 618 HIV positive) and 622 from non-MSM were examined over a 36-month period. A total of 651 (52.2%) stool specimens from MSM were positive for protozoa compared with 85 (13%) from non-MSM. There was a significant difference in the prevalence of Blastocystis hominis, Endolimax nana, Entamoeba histolytica/dispar complex, Entamoeba hartmanni, Iodamoeba butschlii, and Enteromonas hominis detected between MSM and non-MSM (P<0.001). The only notable difference between HIV-negative and HIV-positive MSM was that HIV-infected MSM were found to more likely have a Cryptosporidium parvum infection. Entamoeba histolytica was found in 3 patients, E. dispar in 25, and E. moshkovskii in 17, all of whom were MSM. When compared with a control group, MSM were significantly more likely to harbor intestinal protozoa and have multiple parasites present. The results of this study show high rates of enteric parasites persist in MSM and highlight the importance of testing for intestinal parasites in MSM. This is the first report of E. moshkovskii from MSM.     

Conditional neuronal nitric oxide synthase overexpression impairs myocardial contractility

The role of the neuronal NO synthase (nNOS or NOS1) enzyme in the control of cardiac function still remains unclear. Results from nNOS(-/-) mice or from pharmacological inhibition of nNOS are contradictory and do not pay tribute to the fact that probably spatial confinement of the nNOS enzyme is of major importance. We hypothesize that the close proximity of nNOS and certain effector molecules like L-type Ca(2+)-channels has an impact on myocardial contractility. To test this, we generated a new transgenic mouse model allowing conditional, myocardial specific nNOS overexpression. Western blot analysis of transgenic nNOS overexpression showed a 6-fold increase in nNOS protein expression compared with noninduced littermates (n=12; P<0.01). Measuring of total NOS activity by conversion of [(3)H]-l-arginine to [(3)H]-l-citrulline showed a 30% increase in nNOS overexpressing mice (n=18; P<0.05). After a 2 week induction, nNOS overexpression mice showed reduced myocardial contractility. In vivo examinations of the nNOS overexpressing mice revealed a 17+/-3% decrease of +dp/dt(max) compared with noninduced mice (P<0.05). Likewise, ejection fraction was reduced significantly (42% versus 65%; n=15; P<0.05). Interestingly, coimmunoprecipitation experiments indicated interaction of nNOS with SR Ca(2+)ATPase and additionally with L-type Ca(2+)- channels in nNOS overexpressing animals. Accordingly, in adult isolated cardiac myocytes, I(Ca,L) density was significantly decreased in the nNOS overexpressing cells. Intracellular Ca(2+)-transients and fractional shortening in cardiomyocytes were also clearly impaired in nNOS overexpressing mice versus noninduced littermates. In conclusion, conditional myocardial specific overexpression of nNOS in a transgenic animal model reduced myocardial contractility. We suggest that nNOS might suppress the function of L-type Ca(2+)-channels and in turn reduces Ca(2+)-transients which accounts for the negative inotropic effect.     

Multifactorial dysphagia complicated by esophago-bronchial fistula

Dysphagia in an elderly patient necessitates urgent clinical evaluation to exclude the possibility of an underlying esophageal malignancy. Atherosclerotic aortic aneurysms are common in old age, but dysphagia aortica resulting from compression of the esophagus by an aortic aneurysm is a rare cause for dysphagia. Development of a malignant esophago-airway fistula can occur from a variety of tumors, the most common of which is esophageal cancer. A case of longstanding dysphagia resulting from dysphagia aortica later developing an esophageal malignancy complicated by esophago-bronchial fistula is outlined in this unique case report.