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891.
We assessed the pharmacological activity of anabaseine, a toxin found in certain animal venoms, relative to nicotine and anabasine on a variety of vertebrate nicotinic receptors, using cultured cells, the Xenopus oocyte expression system, contractility assays with skeletal and smooth muscle strips containing nicotinic receptors and in vivo rat prostration assay involving direct injection into the lateral ventricle of the brain. Anabaseine stimulated every subtype of nicotinic receptor that was tested. It was the most potent frog skeletal muscle nicotinic receptor agonist. At higher concentrations it also blocked the BC3H1 (adult mouse) muscle type receptor ion channel. The affinities of the three nicotinoid compounds for rat brain membrane alpha-bungarotoxin binding sites and their potencies for stimulating Xenopus oocyte homomeric alpha7 receptors, expressed in terms of their active monocation concentrations, displayed the same rank order, anabaseine>anabasine> nicotine. Although the maximum currents generated by anabaseine and anabasine at alpha7 receptors were equivalent to that of acetylcholine, the maximum response to nicotine was only about 65% of the acetylcholine response. At alpha4-beta2 receptors the affinities and apparent efficacies of anabaseine and anabasine were much less than that of nicotine. Anabaseine, nicotine and anabasine were nearly equipotent on sympathetic (PC12) receptors, although parasympathetic (myenteric plexus) receptors were much more sensitive to anabaseine and nicotine but less sensitive to anabasine. These differences suggest that there may be different subunit combinations in these two autonomic nicotinic receptors. The preferential interactions of anabaseine, anabasine and nicotine with different receptor subtypes provides molecular clues that should be helpful in the design of selective nicotinic agonists.  相似文献   
892.
Nucleic acid amplification techniques for the diagnosis of tuberculosis (TB) are rapidly being developed. Scant work, however, has focused on pericardial TB. Using cryopreserved specimens from a prior study of pericarditis, we compared PCR to culture and histopathology for the diagnosis of tuberculous pericarditis in 36 specimens of pericardial fluid and 19 specimens of pericardial tissue from 20 patients. Fluid and tissue were cultured on Lowenstein-Jensen and Middlebrook solid media and in BACTEC radiometric broth. Tissue specimens were stained with hematoxylin-eosin, Ziehl-Neelsen, auramine O, and Kinyoun stains and were examined for granuloma formation and acid-fast bacilli. PCR was performed with both fluid and tissue with IS6110-based primers specific for the Mycobacterium tuberculosis complex by published methods. Sixteen of the 20 patients had tuberculous pericarditis and 4 patients had other diagnoses. TB was correctly diagnosed by culture in 15 (93%) patients, by PCR in 13 (81%) patients, and by histology in 13 of 15 (87%) patients. PCR gave one false-positive result for a patient with Staphylococcus aureus pericarditis. Considering the individual specimens as the unit of analysis, M. tuberculosis was identified by culture in 30 of 43 specimens (70%) from patients with tuberculous pericarditis and by PCR in 14 of 28 specimens (50%) from patients with tuberculous pericarditis (P > 0.15). The sensitivity of PCR was higher with tissue specimens (12 of 15; 80%) than with fluid specimens (2 of 13; 15%; P = 0.002). In conclusion, the overall accuracy of PCR approached the results of conventional methods, although PCR was much faster. Therefore, PCR merits further development in this regard. The sensitivity of PCR with pericardial fluid was poor, and false-positive results with PCR remain a concern.  相似文献   
893.
Atypical Epstein-Barr virus (EBV) infection developed in a patient under intermittent administration of FK506 (one dose in 10 days) after living-related liver transplantation. The clinical course was similar to severe chronic active EBV infection syndrome (SCAEBV), which is characterized by extremely high titers of antibody to EBV antigens. The clinical symptoms improved without graft rejection even after the cessation of FK506; however, the titers of antibody to EBV antigens remained at high levels. It was considered that: (i) even intermittent use of FK506 could influence the immune response, which then induced atypical EBV infection similar to SCAEBV; and (ii) the impaired immune response, especially to EBV antigens, remained after complete cessation of FK506.  相似文献   
894.
AIMS: While psychiatric symptoms are common in the general population and even more prevalent in alcoholics, their clinical implications are not clear. The goal of this study was to establish the life-time rates of several independent and concurrent mood and anxiety disorders in alcoholics, controls and their relatives. DESIGN: Structured interviews were administered to alcoholics entering treatment, their relatives, and controls. SETTING: The study was carried out in six different centers in the United States as part of the Collaborative Study on the Genetics of Alcoholism (COGA). PARTICIPANTS: Data were gathered from 2713 alcohol dependent subjects (probands and their alcoholic relatives) and 919 controls. MEASUREMENTS: The timeline-based Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) interview was administered face to face by trained, closely supervised interviewers. The life-time rates for concurrent and independent disorders were determined for three DSM-III-R major mood and four major anxiety disorders. FINDINGS: Some form of independent mood disorder was seen during the life-time in slightly fewer alcoholics than controls (14.0% and 17.1%), but alcoholics did show higher rates of independent bipolar disorder (2.3% vs. 1.0%). The life-time rate for independent anxiety disorders was significantly higher in alcoholics than controls (9.4% vs. 3.7%), with most of the differential related to panic disorder (4.2% vs. 1.0%) and social phobia (3.2% vs. 1.4%), but no significant group differences for agoraphobia or obsessive-compulsive disorder. In general, these findings regarding mood and anxiety disorders were reflected in close relatives. CONCLUSIONS: The large majority of alcohol-dependent men and women in this sample did not have any of the independent mood or anxiety disorders evaluated here. However, there was evidence of enhanced risks among alcoholics for independent bipolar, panic and social phobic disorders. Studies which do not distinguish carefully between independent and concurrent mood and anxiety disorders in alcoholics are likely to report much higher rates of co-morbid psychiatric disorders than those that distinguish between the two types of syndromes.  相似文献   
895.
The dopamine transporter (DAT) plays an important role in the plasmalemmal reuptake of dopamine and, thus, in the termination of normal dopaminergic neurotransmission. DAT is also a major binding site for cocaine and other stimulants, the psychoactive effects of which are associated primarily with the inhibition of dopamine reuptake within mesocorticolimbic dopaminergic neurons. We used electron microscopy with an anti-peptide antiserum directed against the N-terminal domain of DAT to determine the subcellular localization of this transporter in the rat ventral tegmental area (VTA), the region that contains the cell bodies and dendrites of these dopaminergic neurons. We show that in the VTA, almost 95% of the DAT immunogold-labeled profiles are neuronal perikarya and dendrites, and the remainder are unmyelinated axons. Within perikarya and large proximal dendrites, almost all of the DAT immunogold particles are associated with intracellular membranes, including saccules of Golgi and cytoplasmic tubulovesicles. In contrast, within medium- to small-diameter dendrites and unmyelinated axons, most of the DAT gold particles are located on plasma membranes. In dually labeled tissue, peroxidase reaction product for the catecholamine-synthesizing enzyme tyrosine hydroxylase is present in DAT-immunoreactive profiles. These findings suggest that intermediate and distal dendrites are both the primary sites of dopamine reuptake and the principal targets of cocaine and related psychostimulants within dopaminergic neurons in the VTA.  相似文献   
896.
Efficacy of anecaine (A) (bupivacaine, Pliva) and marcaine (M) (bupivacaine, Astra) in central neuroaxial block combined with sedation is compared. In the group with epidural block (n = 167, ASA I-III), 102 patients were given anecaine and 65 marcaine in equivalent doses. In the group with spinal block (n = 82, ASA I-III), anecaine was administered to 52 and marcaine to 30 patients. In the epidural block group a catheter was placed at L2-3 or L3-4 with cranial direction. A test dose of bupivacaine (20 mg) was followed after 5-7 min by the main dose of 2 mg.kg-20 mg. Propofol was given for partial suppression of consciousness at a continuous infusion rate 1.6 mg.kg.hr. In spinal block group, bolus dose of bupivacaine (10-20 mg) was injected through the subarachnoidal approach at L2-3 or L3-4. Diazepam (0.1 mg.kg.hr) was used for sedation. Block onset, duration of sensor and motor block, and of effective analgesia were evaluated in all groups. Hemodynamics and respiratory function were monitored. Moderate hypotension (16-17% decline from basic values) was observed in all patients irrespective of bupivacaine brand. In a comparative non-randomized study anecaine showed a faster onset of block and longer duration of clinical effect than marcaine in epidural and spinal anesthesia for orthopedic surgery on the lower limbs.  相似文献   
897.
Neurofilaments (NFs) are prominent components of large myelinated axons and probably the most abundant of neuronal intermediate filament proteins. Here we show that mice with a null mutation in the mid-sized NF (NF-M) subunit have dramatically decreased levels of light NF (NF-L) and increased levels of heavy NF (NF-H). The calibers of both large and small diameter axons in the central and peripheral nervous systems are diminished. Axons of mutant animals contain fewer neurofilaments and increased numbers of microtubules. Yet the mice lack any overt behavioral phenotype or gross structural defects in the nervous system. These studies suggest that the NF-M subunit is a major regulator of the level of NF-L and that its presence is required to achieve maximal axonal diameter in all size classes of myelinated axons.  相似文献   
898.
The alcohol breath test (ABT) is evaluated for variability in response to changes in physiological parameters. The ABT was originally developed in the 1950s, at a time when understanding of pulmonary physiology was quite limited. Over the past decade, physiological studies have shown that alcohol is exchanged entirely within the conducting airways via diffusion from the bronchial circulation. This is in sharp contrast to the old idea that alcohol exchanges in the alveoli in a manner similar to the lower solubility respiratory gases (O2 and CO2). The airway alcohol exchange process is diffusion (airway tissue) and perfusion (bronchial circulation) limited. The dynamics of airway alcohol exchange results in a positively sloped exhaled alveolar plateau that contributes to considerable breathing pattern-dependent variation in measured breath alcohol concentration measurements.  相似文献   
899.
The purpose of this study was to examine the influence of the type of exercise (running vs. cycling) on the O2 uptake V(O2) slow component. Ten triathletes performed exhaustive exercise on a treadmill and on a cycloergometer at a work rate corresponding to 90% of maximal VO2 (90% work rate maximal V(O2)). The duration of the tests before exhaustion was superimposable for both type of exercises (10 min 37 s +/- 4 min 11 s vs. 10 min 54 s +/- 4 min 47 s for running and cycling, respectively). The V(O2) slow component (difference between V(O2) at the last minute and minute 3 of exercise) was significantly lower during running compared with cycling (20.9 +/- 2 vs. 268.8 +/- 24 ml/min). Consequently, there was no relationship between the magnitude of the V(O2) slow component and the time to fatigue. Finally, because blood lactate levels at the end of the tests were similar for both running (7.2 +/- 1.9 mmol/l) and cycling (7.3 +/- 2.4 mmol/l), there was a clear dissociation between blood lactate and the V(O2) slow component during running. These data demonstrate that 1) the V(O2) slow component depends on the type of exercise in a group of triathletes and 2) the time to fatigue is independent of the magnitude of the V(O2) slow component and blood lactate concentration. It is speculated that the difference in muscular contraction regimen between running and cycling could account for the difference in the V(O2) slow component.  相似文献   
900.
Psychological status was assessed in 120 patients with coronary heart disease (CHD) according to MMPI, Toronto alexithymic scale. Alexithymia was diagnosed in 49.1% of the examinees. They were characterized by difficulties in definition of their feelings, absence of dreams and fantasies, introversion, inclination to depressive response to stress, hypochondria eventuating in senesthopathy. The above psychological and pathopsychological traits in CHD patients require psychotherapeutic and chemotherapeutic correction in order to enhance efficacy of the treatment.  相似文献   
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