Phytochemical and genetic analyses of ancient cannabis from Central Asia

The Yanghai Tombs near Turpan, Xinjiang-Uighur Autonomous Region, China have recently been excavated to reveal the 2700-year-old grave of a Caucasoid shaman whose accoutrements included a large cache of cannabis, superbly preserved by climatic and burial conditions. A multidisciplinary international team demonstrated through botanical examination, phytochemical investigation, and genetic deoxyribonucleic acid analysis by polymerase chain reaction that this material contained tetrahydrocannabinol, the psychoactive component of cannabis, its oxidative degradation product, cannabinol, other metabolites, and its synthetic enzyme, tetrahydrocannabinolic acid synthase, as well as a novel genetic variant with two single nucleotide polymorphisms. The cannabis was presumably employed by this culture as a medicinal or psychoactive agent, or an aid to divination. To our knowledge, these investigations provide the oldest documentation of cannabis as a pharmacologically active agent, and contribute to the medical and archaeological record of this pre-Silk Road culture

Post tracheostomy and post intubation tracheal stenosis: Report of 31 cases and review of the literature

<p>Abstract</p> <p>Background</p> <p>Severe post tracheostomy (PT) and post intubation (PI) tracheal stenosis is an uncommon clinical entity that often requires interventional bronchoscopy before surgery is considered. We present our experience with severe PI and PT stenosis in regards to patient characteristics, possible risk factors, and therapy.</p> <p>Methods</p> <p>We conducted a retrospective chart review of 31 patients with PI and PT stenosis treated at Lahey Clinic over the past 8 years. Demographic characteristics, body mass index, co-morbidities, stenosis type and site, procedures performed and local treatments applied were recorded.</p> <p>Results</p> <p>The most common profile of a patient with tracheal stenosis in our series was a female (75%), obese (66%) patient with a history of diabetes mellitus (35.4%), hypertension (51.6%), and cardiovascular disease (45.1%), who was a current smoker (38.7%). Eleven patients (PI group) had only oro-tracheal intubation (5.2 days of intubation) and developed web-like stenosis at the cuff site. Twenty patients (PT group) had undergone tracheostomy (54.5 days of intubation) and in 17 (85%) of them the stenosis appeared around the tracheal stoma. There was an average of 2.4 procedures performed per patient. Rigid bronchoscopy with Nd:YAG laser and dilatation (mechanical or balloon) were the preferred methods used. Only 1(3.2%) patient was sent to surgery for re-stenosis after multiple interventional bronchoscopy treatments.</p> <p>Conclusion</p> <p>We have identified putative risk factors for the development of PI and PT stenosis. Differences in lesions characteristics and stenosis site were noted in our two patient groups. All patients underwent interventional bronchoscopy procedures as the first-line, and frequently the only treatment approach.</p

Do head lice spread in swimming pools?

This study investigated the potential for head lice transmission in swimming pools using an in vitro experiment and a field trial. In the former study, head lice were submerged for 20 min in aqueous solutions at 25 ± 1 °C: deionized water, sea water, salt solutions (30, 60, 120 and 240 g/l), and chlorinated water (0.2, 2 and 5 mg/l). In all trials, lice located on cut hairs became immobile and did not respond to physical prodding. After entering stasis, no movement was observed until after rescue from submersion and a brief recovery period (0–1 min). Upon recovery, all lice fed and no mortality was observed within the next 4 h. In the field trial, four naturally infected individuals swam in a chlorinated pool for 30 min. No loss of lice or head to head transfer was observed. These results indicated that although head lice survive immersion, head lice transmission is unlikely to occur via the water of swimming pools

Stem cells regulate myocyte growth in the aging rat heart

Whether aging affects the number of primitive cells in the heart is currently unknown. Therefore, the numerical density of undifferentiated cells was measured quantitatively in the left ventricular myocardium of rats at 4 and 27 months of age. The numbers of c-kit, MDR1 and Sca-1-like positive cells per 100 mm2 of tissue were 10±3, 20±9 and 4±1 in rats at 4 months. Corresponding values in rats at 27 months, were 29±8, 84±32 and 16±5. These increases with age were statistically significant. Stem cell surface antigens were maintained in cardiac progenitors expressing the transcription factor GATA-4. The frequency of cardiac progenitors was 4-7-fold higher in older rats. Similarly, myocyte precursors, expressing stem cell antigens, MEF2 and a thin cytoplasmic layer of cardiac myosin heavy chain were more numerous in the senescent heart. Importantly, a 6-fold higher myocyte mitotic index was found in old, 620±96/10e6, than in young, 95±31/10e6, rats. In conclusion, the loss of myocytes with age is, at least in part, counterbalanced by myocyte regeneration. Myocyte division is triggered by activation of resident cardiac stem cells, which increases in the senescent heart