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931.
H Bouman SF Klis JC de Groot EH Huizing GF Smoorenburg JE Veldman 《Canadian Metallurgical Quarterly》1998,117(1-2):119-130
Click-evoked auditory brainstem responses were recorded in a prosimian primate, the bush baby (Otolemur garnettii), before and after depletion of serotonin (by systemic injection of para-chlorophenylalanine; pCPA) and up to 20 days after discontinuing pCPA injections (during the recovery of serotonin). Biphasic 100 micros clicks were presented at five repetition rates (13.2, 33.2, 53.2, 73.2, and 93.2 clicks/s; RATE) and sound pressure levels (SPL) were varied in 10 dB steps from 120-60 dB SPL peak equivalent. Absolute latencies of vertex-positive peaks I, III, IV, and V were measured from click onset. The latencies from each wave were statistically analyzed with a two-way analysis of variance using either RATE or SPL (but not both) and TIME AFTER pCPA as independent variables. Prior to pCPA, brainstem response latencies increased as a function of both decreasing SPL and increasing RATE. After pCPA, these normal increases in wave latency increased even more, particularly in response to high click rates. After pCPA was discontinued, measurements taken at weekly intervals indicated that latencies decreased after 1 week, increased to the highest values recorded after 2 weeks, and returned to normal after 3 weeks. These dynamic changes were interpreted to be the result of postsynaptic receptor up-regulation during the 10 days of continuous pCPA administration. These results suggest that serotonin plays an important role in sensory processing at the cellular level and, tonically, facilitates the auditory brainstem response to sound. 相似文献
932.
JW Gobel ME Pierpont JH Moller A Singh JE Edwards 《Canadian Metallurgical Quarterly》1993,14(2):110-115
Diazepam is known to decrease organophosphate nerve agent-induced convulsions, neuropathology, and lethality in rhesus monkeys. We report that, when added to the previously fielded treatment regimen (pyridostigmine, atropine, and pralidoxime chloride), diazepam significantly protects the performance of rhesus monkeys trained in an equilibrium task, the Primate Equilibrium Platform (PEP), against deficits induced by the nerve-agent soman. If administered soon enough to minimize the occurrence of convulsions, diazepam should increase the probability of mission accomplishment and eventual complete recovery from nerve agent poisoning. Diazepam was fielded by the United States military services during Operations Desert Shield and Storm for the treatment of possible organophosphate toxicity. 相似文献
933.
JE Ware M Kosinski B Gandek NK Aaronson G Apolone P Bech J Brazier M Bullinger S Kaasa A Leplège L Prieto M Sullivan 《Canadian Metallurgical Quarterly》1998,51(11):1159-1165
Studies of the factor structure of the SF-36 Health Survey are an important step in its construct validation. Its structure is also the psychometric basis for scoring physical and mental health summary scales, which are proving useful in simplifying and interpreting statistical analyses. To test the generalizability of the SF-36 factor structure, product-moment correlations among the eight SF-36 Health Survey scales were estimated for representative samples of general populations in each of 10 countries. Matrices were independently factor analyzed using identical methods to test for hypothesized physical and mental health components, and results were compared with those published for the United States. Following simple orthogonal rotation of two principal components, they were easily interpreted as dimensions of physical and mental health in all countries. These components accounted for 76% to 85% of the reliable variance in scale scores across nine European countries, in comparison with 82% in the United States. Similar patterns of correlations between the eight scales and the components were observed across all countries and across age and gender subgroups within each country. Correlations with the physical component were highest (0.64 to 0.86) for the Physical Functioning, Role Physical, and Bodily Pain scales, whereas the Mental Health, Role Emotional, and Social Functioning scales correlated highest (0.62 to 0.91) with the mental component. Secondary correlations for both clusters of scales were much lower. Scales measuring General Health and Vitality correlated moderately with both physical and mental health components. These results support the construct validity of the SF-36 translations and the scoring of physical and mental health components in all countries studied. 相似文献
934.
The conditions affording biphasic competition curves in radioligand binding for ligands subjected to metabolic transformation was analyzed theoretically. It was shown that when a competing ligand was subjected to transformation to a ligand that showed higher affinity than the parent compound, biphasic competition curves, which might wrongly be interpreted as indicating the presence of two receptor sites, could be observed in binding assays containing a homogenous receptor population. Biphasic competition curves were seen if the conversion of the competitor occurred according to zero and second order kinetics, as well as by enzymatic catalytic processes. However, when the conversion occurred according to a first order kinetics, the competition curves were uniphasic and resolved only into one-site fits, with the apparent affinity of the competitor reflecting the degree of conversion of the competitor to its metabolite. When the metabolic conversion resulted in a metabolite that showed lower affinity for the receptor than the parent compound, the competition curves became supersteep for conversions according to zero and second order kinetics, as well as for conversion by enzymatic catalytic processes. 相似文献
935.
The recognition of a pathologic entity is only the first step in the chain of events which must be performed for accurate diagnoses and appropriate patient management. Other steps include selection of the type of biopsy to be performed; proper biopsy technique, instrumentation and specimen handling; appropriate fixation; detailed documentation; and postoperative patient instructions. If the clinician performs each step carefully and correctly, the patient is ensured of receiving an accurate diagnosis in the shortest possible period of time. 相似文献
936.
K Sch?nning A Bolmstedt J Novotny OS Lund S Olofsson JE Hansen 《Canadian Metallurgical Quarterly》1998,14(16):1451-1456
An N-glycan (N306) at the base of the V3 loop of HIV-BRU gp120 is shielding a linear neutralization epitope at the tip of the V3 loop on oligomeric Env. In contrast, this epitope is readily antigenic on monomeric gp120. Immunization with recombinant monomeric HIV-BRU gp120 may thus be expected to elicit antibodies preferentially neutralizing mutant variants of HIV-BRU lacking the N306 glycan. Therefore, two guinea pigs were immunized with monomeric wild-type HIV-BRU gp120 possessing the N306 glycan and immune sera were tested for neutralization against target viruses HIV-BRU, -A308, and -A308T321. HIV-A308 and HIV-A308T321 lack the N306 glycan; HIV-A308T321 contains an additional mutation at the tip of V3 rendering it resistant to MAb binding at this epitope. Both immune sera preferentially neutralized the two mutant virus variants lacking the N306 glycan, with a 10- to 20-fold increase in neutralization titer compared with the wild-type HIV-BRU. Thus, immunization with monomeric HIV-BRU gp120 elicited antibodies preferentially neutralizing HIV variants lacking the N306 glycan. In addition to antibodies directed against the tip of V3, other antibodies directed against epitopes shielded by the N306 glycan on the envelope oligomer were elicited by the immunization, as demonstrated by the ability of the immune sera to neutralize HIV-A308T321. One such epitope was overlapping the NEA-9284 epitope located at the amino-terminal flank of the V3 loop. Our results demonstrate that monomeric gp120 contains immunogenic structures inaccessible on the envelope oligomer. The limited ability of recombinant gp120 vaccines to induce neutralizing antibodies against primary isolates may thus not exclusively reflect genetic variation. 相似文献
937.
L Wooninck JE Strassmann RC Fleischer RR Warner 《Canadian Metallurgical Quarterly》1998,7(11):1613-1614
Securing informed consent, though vital to any defense, will not shield a practitioner from a malpractice claim. That is because courts generally hold that patients cannot consent to negligent treatment. 相似文献
938.
E Donois V del Marmol A Ta?eb G Ghanem JE Surlève-Bazeille 《Canadian Metallurgical Quarterly》1998,20(4):275-287
Chemical antioxidants and catalase have been shown to be ineffective in improving the motility of ram spermatozoa in a chemically-defined diluent (RSD-1). In an attempt to identify the biochemical basis of this observation, the activity of aromatic amino acid oxidase (AAAO), the enzyme responsible for generation of hydrogen peroxide in ram and bull spermatozoa, has been investigated. Ram spermatozoa contained higher levels of AAAO activity than bull spermatozoa, although the physico-chemical properties of the enzyme were generally similar in both species. Components of the medium had a marked effect upon AAAO activity. In the presence of glutamate and 3-(N-morpholino)propanesulfonic acid (MOPS), AAAO activity was decreased. Pyruvate appeared to increase AAAO activity. This was due to the ability of this substance to destroy hydrogen peroxide. Pyruvate in RSD-1 works as an effective antioxidant and therefore eliminates the need for other antioxidants in the semen diluent. 相似文献
939.
AH Jimenez GH Tofler X Chen ME Stubbs HS Solomon JE Muller 《Canadian Metallurgical Quarterly》1993,72(1):47-52
Exposition of results and complications in 7,162 consecutive sessions with Shockwave Extracorporeal Lithotripsy (SWEL) applied to 3,950 lithiasis located at all levels of the urinary tract. These procedures have been performed without sedation or anaesthesia. Diuresis was not forced during or after treatment with serotherapy, mannitol, or diuretics. Treatment was conducted in an outpatients clinic in all cases. The treatment/lithiasis ratio in this initial series was 1.7. Following therapy, 7.09% of patients treated attended the emergency unit due to colic pain/fever. 3.60% of patients treated required hospitalization due to major complications: subcapsular-retroperitoneal haematoma, 9 cases; ureteral obstruction, 120 cases; septicemia, 22 cases; renal function annulment, 11 cases and death, 2 cases. 相似文献
940.