共查询到20条相似文献,搜索用时 15 毫秒
1.
The Trk family, a group of high-affinity neurotrophin receptors, is divided into three subtypes, TrkA, TrkB and TrkC. These were originally found in neural elements, and are involved in neural development, maintenance and survival. Recent studies have shown that non-neural cells in vitro also express mRNA encoding some neurotrophin receptors. In our preliminary study, TrkB-like immunoreactivity (LI) was found in the various non-neural cells in the rat periodontal ligament. The present study was undertaken to clarify which cell types express Trk-LI, in particular two types of TrkB-LI, in the periodontal ligament of mature rats, using an immunocytochemical technique with polyclonal antibodies. Intense full-length TrkB-LI was clearly recognized in non-neural cells such as fibroblasts, osteoclasts, odontoclasts and cementoblasts as well as in neural elements. Relatively large cells with many cytoplasmic processes were also frequently immunopositive for full-length TrkB. Immunocytochemistry for TrkB[TK-], a truncated type, also demonstrated a similar immunostaining pattern to that of full-length TrkB in non-neural periodontal cells, and intense positive reactions in endothelial cells. Some non-neural cells were positive for TrkA and TrkC. These findings suggest that neurotrophic factors, the ligands of the Trk family, have certain effects on the proliferation and/or differentiation of non-neural cells, as well as on their neurotrophic functions. 相似文献
2.
3.
Detailed investigations on pharmacological properties of biologically active thymus extract were performed. Its acute and chronic toxicity was determined. Influence on the circulatory and the respiratory systems as well as on the parenchymatous and the smooth muscle organs, development of fetuses and reproductive functions were evaluated. Preparation TFX proved to be well tolerated and its acute action was manifested only at high doses injected intravenously. Its effect on the smooth muscle organs and its teratogenic activity were determined in the long-term experiments. It was assumed that it can be introduced in clinical use excluding women in the reproductive period. 相似文献
4.
Katz Donald B.; Rogers Ronald F.; Steinmetz Joseph E. 《Canadian Metallurgical Quarterly》2002,116(5):824
Behavioral and neural correlates of latent inhibition (LI) during eyeblink conditioning were studied in 2 experiments. In Experiment 1, rabbits (Oryctolagus cuniculus) were conditioned after 8 days of tone conditioned stimulus (CS) presentations or 8 days of context-alone experience. LI was seen in the CS-preexposed rabbits when a relatively intense (5 psi) airpuff unconditioned stimulus was paired with the CS. In Experiment 2, rabbits were given 0, 4, or 8 days of CS preexposures or context-alone experience. Hippocampal activity was monitored from the 8-day CS- or context-exposure rabbits. The LI effect was seen only in rabbits given 4 days of CS preexposure, thus suggesting that LI depended largely on the rate of acquisition in the context-preexposed control group. The neural recordings showed that the hippocampus was sensitive to the relative novelty of the stimuli and the overall context, regardless of whether exposure to stimuli and context promoted LI. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
The use of oral implants opened a wide range of prosthetic treatment possibilities in edentulous patients. Although the reported success rates of oral implants are high, failures do occur. This paper reviews the current knowledge about the aetiology, the signs and symptoms and the possible influencing factors of implant failure. Possible causes of implant failure are thought to be infection of the periimplant tissues, occlusal overload, or a combination of both. Nevertheless, pinpointing one of these as the aetiological factor in a particular case is difficult and should be handled reluctantly. Although the cause might seem obvious, influencing factors could play a role as well. Gaining insight into these processes might stimulate the adoption of preventive action and therefore increase the predictability of the treatment outcome with oral implants. 相似文献
6.
The aim of this study was to characterize the changes in the quantitative expression of beta 2-integrins and L-selectin detected by means of fluorochrome-conjugated monoclonal antibodies and flow cytometry on leukocytes in the systemic circulation after a major musculoskeletal trauma, i.e. hip replacement surgery, and to relate these changes to parameters of the acute-phase response [plasma acute-phase reactants (C-reactive protein, CRP, and interleukin-6, IL-6) and parameters of coagulation activation (thrombin-antithrombin III complexes, TAT)]. Eight patients with either primary or secondary osteoarthritis of the hip received uncemented total hip prostheses. LFA-1 (CD11a/CD18) was upregulated on granulocytes during the operation. MAC-1 (CD11b/CD18) expression on monocytes increased to peak levels 20 h after surgery, whereas the L-selectin (CD62L) expression on monocytes and granulocytes reached peak values at the end of surgery. The changes in expression of LFA-1 on monocytes, MAC-1 on granulocytes and p150,95 (CD11c/CD18) on monocytes and granulocytes during and after the operation did not reach statistical significance. TAT and IL-6 increased during surgery and reached peak values at the end of the operation and 20 h after surgery, respectively. In contrast, CPR concentrations increased after surgery with peak levels 44 h postoperatively. Significant upregulation of LFA-1 on granulocytes and L-selectin on monocytes and granulocytes preceded the increase in IL-6 which again preceded the increase in CRP. However, the up- or downregulation of leukocyte beta 2-integrins and L-selectin during and after surgery was not significantly correlated with the increase in IL-6. The increases in TAT correlated well with the upregulation of L-selectin on monocytes, but not with the beta 2-integrins known to participate in the coagulation process in vitro. The rise in CRP was inversely correlated with the maximal increase in expression of MAC-1 on monocytes. In conclusion, the changes in leukocyte adhesion molecules during and after surgery indicate changes in critical leukocyte functions. The lack of correlation between quantitative up- and downregulation of leukocyte beta 2-integrins and parameters of the acute phase response suggests that these processes are regulated through independent pathways or that functional up- and downregulation of adhesion molecules, shedding, leukocyte-endothelial adhesion and mobilization of new unactivated cells may result in a net estimate of leukocyte activation not suspected to be positively correlated to acute-phase reactants. 相似文献
7.
A brief review of aetiological aspects, clinical features and treatment of Papillon-Lefèvre syndrome, is mentioned. A case is reported of a girl having typical features of syndrome. In part II of this article we include oral rehabilitation of these patients using osseointegrated implants. 相似文献
8.
9.
Bradshaw Catherine P.; Mitchell Mary M.; O'Brennan Lindsey M.; Leaf Philip J. 《Canadian Metallurgical Quarterly》2010,102(2):508
Although there is increasing awareness of the overrepresentation of ethic minority students—particularly Black students—in disciplinary actions, the extant research has rarely empirically examined potential factors that may contribute to these disparities. The current study used a multilevel modeling approach to examine factors at the child (e.g., teacher-rated disruptive behavior problems) and classroom or teacher levels (e.g., teacher ethnicity, level of disruptive behavior in classroom) that may contribute to the overrepresentation of minority students in office disciplinary referrals (ODRs). Data come from 6,988 children in 381 classrooms at 21 elementary schools. The analyses indicated that even after controlling for the student's level of teacher-rated behavior problems, teacher ethnicity, and other classroom factors, Black students were significantly more likely than White students to receive ODRs. Results also suggested that ethnic match between students and their teachers did not reduce the risk for referrals among Black students. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
This reply to F. H. Borgen (see record 1995-27394-001) and R. V. Dawis (see record 1995-27395-001)) argues that studying the causes, attributes, and benefits of participants' psychological experiencing of leisure is more likely to advance knowledge of leisure's effects on participants than efforts that recapitulate the study of vocational interests. The conceptual relation of the construct of needs to interests and values is explained, and it is suggested that K. Holmberg, D. Rosen, and J. L. Holland's (1990) taxonomy may lack validity because of its reliance on the armchair judgments of "experts." This article disagrees with Borgen's suggestion that H. E. A. Tinsley and B. D. Eldredge's (see record 1995-27399-001) findings are critical of J. L. Holland's (1985) theory and suggests a procedure for attempting to develop a valid taxonomy of leisure activities using Holland's theory. Nevertheless, Holland's theory largely ignores the amount of exertion intrinsic to an activity, and exertion is the most important dimension for distinguishing among leisure activities. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
11.
PD Nowell DJ Buysse CF Reynolds PJ Hauri T Roth EJ Stepanski MJ Thorpy E Bixler A Kales RL Manfredi AN Vgontzas DM Stapf PR Houck DJ Kupfer 《Canadian Metallurgical Quarterly》1997,154(10):1412-1416
OBJECTIVE: Primary insomnia and insomnia related to mental disorders are the two most common DSM-IV insomnia diagnoses, but distinguishing between them is difficult in clinical practice. This analysis was performed to identify clinical factors used by sleep specialists to distinguish primary insomnia from insomnia related to mental disorders. METHOD: Clinicians evaluated 216 patients referred for insomnia at five clinical sites, rated a list of clinical factors judged to contribute to each patient's presentation, and assigned diagnoses. Analysis of variance was performed, with contributing factors as the dependent variable and diagnostic group and clinic location as independent variables. RESULTS: Sleep specialists rated a psychiatric disorder as a stronger factor for insomnia related to mental disorders and rated negative conditioning and sleep hygiene as stronger factors for primary insomnia. However, a psychiatric disorder was rated as a contributing factor for 77% of patients who received a first diagnosis of primary insomnia. CONCLUSIONS: While neither sleep hygiene nor negative conditioning is a diagnostic criterion in DSM-IV, these results support the face validity of these clinical factors distinguishing between primary insomnia and insomnia related to mental disorders. The use of a psychiatric disorder as an inclusion criterion for insomnia related to mental disorders and an exclusion criterion for primary insomnia reinforces a categorical distinction between the two diagnoses, but the contribution of psychiatric symptoms in primary insomnia appears to be a clinically relevant one. These findings suggest the need for studies on the validity of negative conditioning and sleep hygiene in the etiology of primary insomnia, as well as on the significance of psychiatric disorders, especially depression, in primary insomnia. 相似文献
12.
V. M. Kryachek 《Powder Metallurgy and Metal Ceramics》2004,43(11-12):581-592
Success in research, production, and testing of traditional friction powder materials is considered. Areas of their practical application are demonstrated. New methods for forming friction-aimed articles and coatings upon them are analyzed. 相似文献
13.
Increased attention to the cognitive and learning difficulties of adults has meant that some adults with primary emotional problems are being diagnosed as learning disabled; this in turn impedes the provision of appropriate counseling interventions and promotes inappropriate vocational placement. Traditional test instruments are inadequate for determining the presence and nature of the learning problems that adults are experiencing. Three case studies are presented to demonstrate the efficacy of Feuerstein's Learning Potential Assessment Device (LPAD) to discriminate among cognitive and affective variables that may be contributing to adults' learning difficulties. There follows a critical discussion focusing on the key characteristics of the LPAD that were instrumental in identifying the factors contributing to the 3 clients' learning difficulties. The four areas of focus are (a) the content-free nature of tests, (b) the examiner–examinee interaction, (c) the change in orientation to the process rather than the end product, and (d) modifications in test interpretation. Implications for counselors assessing adults with learning difficulties in academic and vocational settings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
14.
K Yoshida Y Takamatsu Y Adachi M Kishi H Sekine T Shigematsu 《Canadian Metallurgical Quarterly》1996,37(2):55-62
Endoglucanase production was measured in culture filtrates of four species of Saccobolus growing in media containing glucose or crystalline cellulose as the only carbon sources. Enzyme activity was four to seven times higher in the presence of cellulose than glucose. S. saccoboloides showed maximal growth and enzyme production. The extracellular proteins secreted during growth on cellulose were separated by polyacrylamide gel electrophoresis and stained for proteins. A zymogram technique was used to visualize bands with endoglucanase activity. The four species showed different protein and isoenzyme patterns. 相似文献
15.
AG Schoofs FC Odds R Colebunders M Ieven H Goossens 《Canadian Metallurgical Quarterly》1998,41(5-6):203-211
The Candida species isolated from oral rinses of 130 human immunodeficiency virus (HIV) infected patients were compared with those of 130 healthy non-matched volunteers. The oral rinses were plated on CHROMagar Candida medium (CAC) and on CAC supplemented with 10 micrograms (CF10) and 100 micrograms (CF100) of fluconazole per ml. The prevalence of non-albicans Candida spp. in oral rinses of HIV-infected patients and their correlation with the clinical and epidemiological characteristics of the patients were studied. Susceptibility of the Candida spp. isolated was determined by a microbroth dilution method based on the NCCLS reference procedure. Results of susceptibility tests of the yeast isolates were compared with their growth at the time of isolation on CAC supplemented with fluconazole. Thirty-five (30.7%) strains of non-albicans Candida spp. were isolated from the HIV-positive population, vs. seven (15.9%) from the immunocompetent population. Growth on CF10 correlated in 96% of the cases with fluconazole minimum inhibitory concentration (MIC) > 8 micrograms ml-1. Smoking and use of azoles were significantly associated with oral carriage of non-albicans Candida spp. (P < 0.05). The prevalence of non-albicans Candida spp. in HIV-positive persons in oral rinse samples is twice as high as in the HIV-negative population. Smoking and treatment with azoles are risk factors for the oral carriage of non-albicans Candida spp. The isolation of yeasts on CAC plates supplemented with fluconazole allows combination of presumptive yeast identification and fluconazole susceptibility testing. 相似文献
16.
17.
Reports on 3 experiments with Charles River rat pups. When milk infusions were made through oral cannulas in the front of their mouths, 1–20 day old Ss actively ingested the diet, and their intake was related to the length of deprivation. Ss decreased their ingestive responding after they had consumed large volumes of milk. In addition, 1-, 3-, and 6-day-old Ss, when 24-hr deprived, exhibited an intense behavioral activation in response to milk infusion. The behavioral activation appeared to be stimulated primarily by taste and the opportunity to swallow. Milk infusions did not produce activation in older Ss; their behavior was more exclusively ingestive and food directed. Results demonstrate that (a) from birth, rat pups are capable of an active form of ingestion, independent of normal suckling from the mother; (b) such ingestion is controlled by physiological factors; (c) food has arousing properties in young animals; and (d) as pups grow older, their ingestive responding is refined from a generalized and nondirected activation to specific and directed feeding responses. (57 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
18.
19.
20.
M Fladung 《Canadian Metallurgical Quarterly》1999,260(6):574-581
The stability of transgenes in the genome of transformed plants depends strongly on their correct physical integration into the host genome as well as on flanking target DNA sequences. For long-lived species like trees, however, no information is available so far concerning inactivation or loss of transgenes due to gene silencing or somatic genome rearrangement events. In this study, four independently transformed 35S-rolC transgenic hybrid aspen plants (Populus tremula L. x tremuloides Michx.), each harbouring one copy of the transgene, were investigated during continuous growth in the greenhouse. In one of these transgenic lines (Esch5:35S-rolC-#1) individuals frequently show phenotypic reversions, while in the remaining three lines (Esch5:35S-rolC-#3, -#5, -#16) the gene was essentially stable. Molecular analysis including PCR, Southern and Northern assays clearly showed that the transgene had been lost in the revertant tissue of the unstable line. Sequencing of T-DNA right and left borders, and flanking DNA regions, in all four transgenic aspen lines revealed no differences either in the type of flanking DNA (G-C to A-T ratio) or with respect to the presence of enhancers or MAR (matrix associated repeats)-like structures. Primers located within the left and right flanking regions in the three stable lines could be used to recover the target sites from the untransformed plants. This was not possible, however, with the unstable line, indicating that at least one flanking sequence does not derive from the plant target DNA but is of unknown origin. PCR using other primer pairs, and inverse PCR analysis, revealed an additional truncated T-DNA copy of 1050 nucleotides adjacent to the left border of the complete copy in this line. Sequencing of this truncated T-DNA revealed that it represented an inverted copy of part of the right half of the original construct. This special feature would allow the inverted repeat to pair with right border sequences of the complete copy. This would explain the frequently observed reversion resulting in transgene loss as due to intrachromosomal base-pairing leading to double-stranded loops of single-stranded DNA during mitotic cell divisions. 相似文献