Examination of the action of 3,4-methylenedioxymethamphetamine on rat A10 dopamine neurons

Extracellular single cell recording was used to examine the effect of intravenous administration of (−), (+), and (±)-3,4-methylenedioxymethamphetamine (MDMA) on A10 dopamine (DA) neurons in chloral hydrate anesthetized male rats. Both (±)-MDMA and (+)-MDMA inhibited the firing rate of most (79%) A10 DA cells. By contrast, (−)-MDMA induced either no effect or a slight increase in the firing rate of these cells. Analysis of the effects of (±)-MDMA on the firing pattern of the DA cells revealed an overall decrease in the percentage of spikes in bursts but both increases and decreases were seen in the coefficient of variation of interspike intervals. To determine the contribution of 5-HT and DA to the (±)-MDMA-induced inhibition of A10 DA cells rats were pretreated either with the 5-HT synthesis inhibitor p-chlorophenylalanine (PCPA) or the DA synthesis inhibitor α-methyl-p-tyrosine (AMPT). Pretreatment of rats with PCPA did not reduce the ability of (±)-MDMA to inhibit the DA cells. However, in rats pretreated with AMPT, the (±)-MDMA-induced inhibition was blocked and some cells (44%) showed instead an increase in firing rate following administration of (±)-MDMA. The administration of l-3,4-dihydroxyphenylalanine (L -DOPA) to AMPT-treated rats rapidly restored the inhibition of cell firing by (±)-MDMA. In conclusion, the results reported here demonstrate that MDMA has an overall inhibitory effect on A10 DA cells. Despite MDMA's greater potency in releasing 5-HT compared to DA, the inhibitory effect of this drug on A10 DA cells appears to be mediated by the latter transmitter. © 1996 Wiley-Liss, Inc.     

Colonoscopic polypectomy

Despite the frequency with which polypectomy is performed, there is a paucity of information on what technical aspects of polypectomy most effectively remove polyps and minimize complications. The practice of polypectomy is based largely on the observational experience of experts and what gastroenterology fellows have learned from their attending physicians and from experts in postgraduate courses. Moreover, polypectomy technique is not consistent across the United States. In this technique update, the author presents his own methods for treating and observing small, large pedunculated, and large sessile polyps and discusses the advantages, disadvantages, and complications of each technique.     

Melatonin excretion with affect disorders over age 60

Numerous studies have reported low melatonin secretion in depression, but other studies have suggested no deficit or an increase. Alterations of circadian phase or duration of melatonin secretion have also been described. Since melatonin secretion decreases as we age, it seemed interesting to examine melatonin and depression in an aging sample. Volunteers who complained of mood or sleep problems were recruited for studies in which fractional urine specimens were collected for 24 h, both at home and in the laboratory. The major metabolite, 6-sulfatoxymelatonin (aMT6s), was determined by radioimmunoassay. Of 72 volunteers aged 60-78 years, seven had current major depression and 55% had a lifetime history of an affective disorder. A 55-fold range of home aMT6s excretion rates was observed. A lifetime history of any affective disorder was significantly associated with greater log(10)[mesor] aMT6s excretion in home collections and laboratory collections, but current affective disorders were neither significantly related to melatonin excretion nor to aMT6s acrophase timing, onset, offset or duration. These results are only weakly consistent with a photoperiodic hypothesis of depression.     

Evaluation of blood vessels and edema in the airways of asthma patients: regulation with clarithromycin treatment

BACKGROUND: Although airway angiogenesis and edema have been proposed to contribute to the airway remodeling process in patients with asthma, there are few studies looking at these structural components in the airway tissue of asthma patients. Mycoplasma infection may be associated with chronic asthma and has been shown to induce angiogenesis and edema in a murine model. Participants and measurements: We evaluated blood vessels and edema by immunohistochemistry in endobronchial biopsy samples from 10 normal control subjects and 15 patients with mild-to-moderate asthma before and after a 6-week treatment with clarithromycin (n = 8) or placebo (n = 7). Type IV collagen and alpha(2)-macroglobulin were used to identify blood vessels and edema in the tissue, respectively. Mycoplasma pneumoniae was evaluated by polymerase chain reaction. SETTING: National Jewish Medical and Research Center. RESULTS: At baseline, the vascularity, the number of blood vessels, and the edematous area in the airway tissue were not significantly different between asthmatic patients and normal control subjects. However, asthmatic patients demonstrated increased blood vessel size compared with normal control subjects (p = 0.03). After clarithromycin treatment in asthmatic patients, the number of blood vessels was increased (p = 0.02), while edema decreased (p = 0.049). Asthmatic patients who tested positive for M pneumoniae showed a significant increase in vascularity than asthmatic patients who tested negative for M pneumoniae (p = 0.02). CONCLUSION: Our data suggest that angiogenesis and edema may not be significant features of airway remodeling in patients with chronic, mild-to-moderate asthma. Clarithromycin treatment in asthmatic patients could reduce the edematous area as identified by alpha(2)-macroglobulin staining, which may lead to airway tissue shrinkage and cause an artificial increase in the number of blood vessels.     

A novel technique to study the brain's response to pain: proton magnetic resonance spectroscopy

Glutamate, a major excitatory neurotransmitter, has been implicated as an important mediator in the neurotransmission, potentiation, and negative affect associated with pain. We present results showing that a painful stimulus elicits a dynamic increase in glutamate (9.3% from baseline) concentrations in the anterior cingulate cortex, detectable using proton Magnetic Resonance Spectroscopy ((1)H-MRS). Increases in glutamine levels were also seen, which correlate strongly with the subjective level of pain experienced by participants (r(2) = 0.58, P < 0.01). These novel findings are the first time a dynamic change in glutamate and glutamine levels from baseline in response to an external stimuli has been measured in a single proton MRS scanning session. As such, this report demonstrates the efficacy of (1)H-MRS as a non-invasive tool for the study of neural responses to pain in vivo. The paradigm used in this study demonstrates that dynamic glutamate/glutamine changes due to stimulation are measurable by proton MRS, and could provide a means of testing novel pharmaceutical agents and other treatments for chronic pain.     

Prevalence,awareness, treatment,and control of hypertension in Nigeria in 1995 and 2020: A systematic analysis of current evidence

Improved understanding of the current burden of hypertension, including awareness, treatment, and control, is needed to guide relevant preventative measures in Nigeria. A systematic search of studies on the epidemiology of hypertension in Nigeria, published on or after January 1990, was conducted. The authors employed random‐effects meta‐analysis on extracted crude hypertension prevalence, and awareness, treatment, and control rates. Using a meta‐regression model, overall hypertension cases in Nigeria in 1995 and 2020 were estimated. Fifty‐three studies (n = 78 949) met our selection criteria. Estimated crude prevalence of pre‐hypertension (120‐139/80‐89 mmHg) in Nigeria was 30.9% (95% confidence interval [CI]: 22.0%‐39.7%), and the crude prevalence of hypertension (≥140/90 mmHg) was 30.6% (95% CI: 27.3%‐34.0%). When adjusted for age, study period, and sample, absolute cases of hypertension increased by 540% among individuals aged ≥20 years from approximately 4.3 million individuals in 1995 (age‐adjusted prevalence 8.6%, 95% CI: 6.5‐10.7) to 27.5 million individuals with hypertension in 2020 (age‐adjusted prevalence 32.5%, 95% CI: 29.8‐35.3). The age‐adjusted prevalence was only significantly higher among men in 1995, with the gap between both sexes considerably narrowed in 2020. Only 29.0% of cases (95% CI: 19.7‐38.3) were aware of their hypertension, 12.0% (95% CI: 2.7‐21.2) were on treatment, and 2.8% (95% CI: 0.1‐5.7) had at‐goal blood pressure in 2020. Our study suggests that hypertension prevalence has substantially increased in Nigeria over the last two decades. Although more persons are aware of their hypertension status, clinical treatment and control rates, however, remain low. These estimates are relevant for clinical care, population, and policy response in Nigeria and across Africa.     

Use of stents to treat kinks causing obstruction in a left internal mammary artery graft

Left internal mammary arteries (LIMA) are used routinely as grafts to the left anterior descending coronary artery (LAD) in selected patients undergoing coronary artery bypass graft (CABG) surgery because of better long-term patency rates. Pathology other than fibrointimal hyperplasia, accelerated atherosclerosis, or thrombus can sometimes cause obstructive lesions in such grafts. This report illustrates a kink in a LIMA graft to the LAD causing an obstructive lesion shortly after surgery and describes the subsequent management of this lesion with intracoronary stents. Cathet. Cardiovasc. Intervent. 46:223–226, 1999. © 1999 Wiley-Liss, Inc.     

Hyperspectral and multispectral bioluminescence optical tomography for small animal imaging

For bioluminescence imaging studies in small animals, it is important to be able to accurately localize the three-dimensional (3D) distribution of the underlying bioluminescent source. The spectrum of light produced by the source that escapes the subject varies with the depth of the emission source because of the wavelength-dependence of the optical properties of tissue. Consequently, multispectral or hyperspectral data acquisition should help in the 3D localization of deep sources. In this paper, we describe a framework for fully 3D bioluminescence tomographic image acquisition and reconstruction that exploits spectral information. We describe regularized tomographic reconstruction techniques that use semi-infinite slab or FEM-based diffusion approximations of photon transport through turbid media. Singular value decomposition analysis was used for data dimensionality reduction and to illustrate the advantage of using hyperspectral rather than achromatic data. Simulation studies in an atlas-mouse geometry indicated that sub-millimeter resolution may be attainable given accurate knowledge of the optical properties of the animal. A fixed arrangement of mirrors and a single CCD camera were used for simultaneous acquisition of multispectral imaging data over most of the surface of the animal. Phantom studies conducted using this system demonstrated our ability to accurately localize deep point-like sources and show that a resolution of 1.5 to 2.2 mm for depths up to 6 mm can be achieved. We also include an in vivo study of a mouse with a brain tumour expressing firefly luciferase. Co-registration of the reconstructed 3D bioluminescent image with magnetic resonance images indicated good anatomical localization of the tumour.     

Retrospective reports of college students' childhood problems

College students and a subsample of their mothers and fathers participated in a study examining their retrospective reports of childhood emotional and behavioral problems experienced by college students. College students and their mothers and fathers exhibited moderate correspondence in their recollection of internalizing and externalizing problems that college students experienced during their childhood. In contrast, college students tended to endorse significantly greater levels of both internalizing and externalizing problems relative to their mothers and fathers. Current psychological symptoms predicted the greater endorsement of childhood internalizing and externalizing problems by college students and the greater endorsement of college students' childhood internalizing problems by their mothers. Further, college students' current perceptions of their parents predicted their endorsement of childhood internalizing problems, and college students' current masculinity and femininity predicted their endorsement of childhood externalizing problems. Results of this study emphasized the importance of noting factors that may be related to retrospective reports.     

Collaborative study of antibiotic medium 3 and flow cytometry for identification of amphotericin B-resistant Candida isolates

Center 1 used the National Committee for Clinical Laboratory Standards M27-A2 method and antibiotic medium 3 (AM3) test to determine amphotericin B resistance in 5 of 30 Candida isolates. These isolates were tested at center 2 by AM3 test and flow cytometry (FC). The agreements (C1-C2) were 90% for AM3 test and FC and 73% for the AM3 tests.