Effects of ethanol on neurotransmitter release by rat brain cortical.

Using a double label technique to preload rat brain cortex slices with different radioactive neurotransmitters (or precursor choline), we have studied the effects of ethanol on the electrically stimulated release of these transmitters. Ethanol inhibited the release of these transmitters, acetylcholine being the most sensitive and occurring at concentrations compatible with moderate to severe intoxication in the rat (IC50 equals 0.17 M). The order of sensitivity to ethanol was acetylcholine greater than serotonin greater than dopamine greater than norepinephrine greater than glutamate greater gamma-aminobutyric acid. Two higher alcohols and two barbiturates were also shown to have a greater inhibitory effect on the stimulated release of acetylcholine than of norepinephrine. The concentrations of all the drugs tested required for 50% inhibition of release of acetylcholine and norepinephrine correlated well with their lipid solubility when corrected for their molecular volumes. The effect of tetrodotoxin and of ouabain on neurotransmitter release was also studied. A comparison of the effects of these two drugs with those of ethanol suggests that the effect of ethanol is consistent with an inhibition of the action potential by this drug, although a specific effect of ethanol on the excitation-coupling process at the synapse cannot by discarded.     

Reciprocal peer teaching: students teaching students in the gross anatomy laboratory

Three common instructional strategies used to teach gross anatomy are lecture, discovery or inquiry-based learning, and cooperative learning. One form of cooperative learning, called reciprocal peer teaching (RPT), illustrates circumstances where students alternate roles as teacher and student. By assuming the responsibility of teaching their peers, students not only improve their understanding of course content, but also develop communication skills, teamwork, leadership, confidence and respect for peers that are vital to developing professionalism early in their medical careers. Traditionally in our Anatomy department, students dissect the entire body using a standard dissection manual. More non-traditionally, however, we have increased cooperative learning in the dissection laboratory by involving students in a series of supplementary RPT activities. During these exercises, 10% of the class practiced their demonstration with course instructors until the students felt prepared to demonstrate the exercise to their classmates. We designed one peer demonstration emphasizing three to six teaching objectives for most of the 40 dissection units. This resulted in a compendium of peer demonstrations for implementation throughout the course. The multitude of diverse exercises permitted each student many opportunities to teach their peers. A debriefing questionnaire was administered at the end of the course demonstrating that 100% of students agreed the RPT experience increased their understanding of the topics they taught and 97% agreed it increased their retention of information they taught to their peers. In addition, 92% agreed that RPT improved their communication skills, which can be applied beyond anatomy to their careers as future physicians.     

Xavier University premedicine program's prescription for success: an interview with JW Carmichael Jr., MS, PhD

This interview of Dr. JW Carmichael was conducted for this special issue of the Journal of the National Medical Association, which highlights American medical education and the experience of African Americans. It was conducted by George Dawson, MD. He serves as editor of the Art in Medicine, History and Health Tidbit sections of the Journal of the National Medical Association. In terms of producing biology and chemistry majors, and, most importantly, from our perspective, premedicine students, the Xavier program is second to none. Under his leadership and with the help of his able staff, it has managed to supply more African-American healthcare students to professional school than any undergraduate programs we could find. Therefore, to us, it seemed fitting that we delved into his vast knowledge, in the hope that his example could be duplicated elsewhere and, perhaps, just maybe we can render the matter of the health disparaties that we speak of so often and that seemingly afflicts our community disproportionally.     

Joint and soft tissue injections: a survey of general practitioners

OBJECTIVES: To determine the type of joint and soft tissue injections carried out by general practitioners (GPs) in the Bath area and factors affecting activity. METHODS: A questionnaire was sent to 360 GPs requesting information on injections carried out during the previous 12 months, referral pathways for injection, barriers to injecting and training. RESULTS: We received 251 replies. The commonest injections were for tennis elbow, glenohumeral joint, knee, supraspinatus tendonitis and carpal tunnel. The majority of GPs (66.4%) carry out most injections themselves, 26.3% refer to a colleague and 7.3% refer to secondary care. Over half (51%) of all the injections are carried out by 15.6% of the GPs. Factors associated with higher levels of injection activity were: male gender, partnership, more than 10 years' experience, a special interest in rheumatology or orthopaedics and working in a rural or mixed practice. The most important barriers to carrying out injections were lack of practical training, lack of confidence and inability to maintain skills. Most GPs have been trained on models. CONCLUSIONS: Most GPs carry out some joint and soft tissue injections, but limit themselves to knees, shoulders and elbows. A small highly active group receive referrals from colleagues. Gender and specialist training strongly influence activity. Many, especially female and part-time, GPs find it hard to maintain their skills and confidence. Training targeted at this group, based in practices and using models and other tools, is likely to increase the number of patients receiving timely injections in general practice.     

Metabonomics and the endocrine system

Proton-NMR-based metabonomics offers a rare opportunity as a definitive screening technique for biofluids and tissue biopsies. The procedure is extraordinary in that it allows the 'complete biochemical picture' to be examined at one time and is able to detect subtle but repeatedly consistent disparities that may be occurring in different, and perhaps unrelated, biochemical pathways. Such metabolic responses to an initial perturbation in homeostasis may be followed over a sequential time-course to their eventual dissipation or consequent sequelae. The application of this technique is beginning slowly to filter into the area of endocrine research and has been used to examine long-term and diffuse physiological alterations that may occur following such events as anabolic steroid treatment of cattle and the exposure of endometrial cells to tamoxifen. Although only modest inroads have been made so far, this technique promises immense potential for future researches within the endocrine field.     

The demonstration of pulmonary neuroendocrine cell hyperplasia with tumorlets in a patient with chronic cough and a history of multiple medical problems

A 58-year-old woman presented with chronic cough felt to be multifactorial secondary to asthma, gastroesophageal reflux disease, and chronic sinusitis. Additional medical history included obstructive sleep apnea, type 2 diabetes, and hypertension. She had a 40- year history of tobacco use, but quit 10 years ago. Her examination was significant for obesity and cobble stoning of the oropharynx. Pulmonary function testing and arterial blood gases were unrevealing. Chest films were normal. High-resolution computed tomography revealed multiple focal lucencies in a mosaic pattern consistent with air trapping and small airways disease. Bronchoscopy revealed normal airways and a noninflammatory bronchoalveolar lavage. Transbronchial biopsies revealed inflammatory infiltrates of the peribronchiolar interstitium. Lung biopsy revealed pulmonary neuroendocrine cell hyperplasia with tumorlets that stained positive for neuroendocrine tissue. We present the case of a woman with chronic cough, multiple medical problems, and pulmonary neuroendocrine cell hyperplasia with tumorlets.     

Common SENSE (sensitivity encoding using hardware common to all MR scanners): a new method for single-shot segmented echo planar imaging.

A new method is presented that enables image acquisition to be segmented into two readouts. This is achieved using a new pulse sequence that creates two components of magnetization with different spatial profiles. Each component of the magnetization is measured in one of the readouts. This produces two images with complimentary "sensitivity profiles" and near identical contrast. The images can be acquired with a reduced data matrix that corresponds to shorter periods of data acquisition. The reduced matrix images are then combined to produce a full matrix image using reconstruction methods previously applied to images from multiple RF coils in the sensitivity encoding (SENSE) technique.The most promising application for this technique is in improving the performance of echo planar imaging (EPI) at high field. In this application, common SENSE obtains two segments of data in a single excitation of the magnetization (i.e., two readouts are performed per shot). The combination of these segments in image space avoids the difficulties normally associated with segmented EPI methods, namely, increased ghosting from discontinuities in the k-space data. The main advantages are a reduction in distortion and blurring. Common SENSE is compatible with parallel imaging and partial Fourier methods.     

A minimally invasive novel design for a vascular-pedicled bone segment for experimental studies of reconstruction of mandibular defects

We describe a new minimally invasive vascularised bone segment (VBS) for experimental reconstruction of the mandible. The study was validated and the feasibility was tested on fresh sheep cadavers. The integrity of the arterial blood supply was confirmed using inferior dental artery static arteriography. A pilot investigation was conducted on two adult sheep. Two full thickness bone cuts 35 mm apart were created in the parasymphyseal region. The inferior dental neurovascular bundle was preserved at the posterior bone cut but not anteriorly. A VBS was created, pedicled only on the inferior dental artery. The continuity of the mandible was maintained using fixation plates and the animals were followed up for 12 weeks. There was complete bony union and restoration of approximately 80% of the bony strength. The model is minimally invasive, reduces the operating time, and does not require special equipment and skills in microvascular anastomosis.     

Effects of oat beta-glucan on innate immunity and infection after exercise stress

PURPOSE: To test the effects of oat beta-glucan (ObetaG) on respiratory infection, macrophage antiviral resistance, and NK cytotoxicity. METHODS: Mice were randomly assigned to one of four groups: Ex-H2O, Ex-ObetaG, Con-H2O, or Con-ObetaG. ObetaG was fed in the drinking water for 10 d before intranasal inoculation of HSV-1 or sacrifice. Exercise consisted of treadmill running to volitional fatigue (approximately 140 min) for three consecutive days. Fifteen minutes after the last bout of exercise or rest, mice (N = 24) were intranasally inoculated with a standardized dose of HSV-1. Mice were monitored twice daily for morbidity and mortality. Additional mice were sacrificed after exercise, peritoneal macrophages were obtained via i.p. lavage and assayed for antiviral resistance to HSV-1 (N = 18), and spleens were harvested and assayed for NK cell cytotoxicity (N = 12). RESULTS: Exercise stress was associated with a 28% increase in morbidity (P = 0.036) and 18% increase in mortality (P = 0.15). Ingestion of ObetaG before infection prevented this increase in morbidity (P = 0.048) and mortality (P = 0.05). Exercise stress was associated with a decrease in macrophage antiviral resistance (P = 0.007), which was blocked by ingestion of ObetaG (P < 0.001). There were no effects of exercise or ObetaG on NK cytotoxicity. CONCLUSION: These data suggest that daily ingestion of ObetaG may offset the increased risk of URTI associated with exercise stress, which may be mediated, at least in part, by an increase in macrophage antiviral resistance.