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181.
J Kaleczyc JP Timmermans M Majewski M Lakomy DW Scheuermann 《Canadian Metallurgical Quarterly》1995,282(1):59-68
The subperiosteal browlift and midface lift combination is a total mobilization of the composite full-thickness soft tissues from the bony skeleton with superior suspension. The object is to correct midfacial ptosis and the "tired" look of the lateral eyelids. It is done in conjunction with a browlift so that a composite correction of the upper and midface is achieved. When indicated, a modified lower cheeklift and the usual procedures for correcting neck deformities are utilized in combination. We believe the procedure is safe and the results reported are natural and long-lasting. This review of 130 cases also stresses technical aspects and the safety of the procedure. 相似文献
182.
D Mellière D Berrahal P Desgranges E Allaire JP Becquemin 《Canadian Metallurgical Quarterly》1998,23(5):342-348
The purpose of this study was to compare the physiological responses of professional and elite road cyclists during an incremental cycle ergometer test. Twenty-five elite cyclists (EC; 23+/-1 yr) and 25 professional cyclists (PC; 25+/-2yr) performed a ramp protocol (increases of 25 W x min(-1)) during which the following parameters were measured: oxygen consumption (VO2), pulmonary ventilation (VE), ventilatory equivalents for oxygen and carbon dioxide (VE x VO2(-1) and VE x VCO2(-1), respectively), respiratory exchange ratio (RER), ventilatory thresholds 1 and 2 (VT1 and VT2, respectively), blood lactate, and electromyographic activity (EMG) of the vastus lateralis. Significant differences existed between the two groups mainly at submaximal intensities, since both VT1 and VT2 occurred at a higher exercise intensity (p<0.001) in PC than in EC (VT2: 80.4+/-6.6 vs 87.0+/- 5.9% VO2max in EC and PC, respectively). Lactate levels showed a similar response in both groups at low-to-moderate intensities (< 300 W), and thereafter blood lactate was significantly higher in EC. Finally, the "electromyographic threshold" (EMGT) occurred at a significantly higher intensity (p < 0.05) in PC when compared to EC (64.7+/-14.2 vs 56.0+/-14.9% VO2max, respectively). It was concluded that, in comparison with EC, PC exhibit some remarkable physiological characteristics such as a high VT2, an important reliance on fat metabolism even at high power outputs, and several neuromuscular adaptations. 相似文献
183.
RT Malison LH Price R Berman CH van Dyck GH Pelton L Carpenter G Sanacora MJ Owens CB Nemeroff N Rajeevan RM Baldwin JP Seibyl RB Innis DS Charney 《Canadian Metallurgical Quarterly》1998,44(11):1090-1098
BACKGROUND: Prior research has suggested reductions in the density of serotonin transporter (SERT) binding sites in blood platelets and post-mortem brain tissue of depressed patients. We sought to determine whether patients with unipolar major depression have diminished SERT availability as assessed by both brainstem [123I] beta-CIT SPECT and platelet [3H]paroxetine binding. METHODS: Drug-free depressed and healthy subjects were injected with 211 +/- 22 MBq [123I] beta-CIT and imaged 24 +/- 2 h later under equilibrium conditions. A ratio of specific to nonspecific brain uptake (V3" = (brainstem-occipital)/occipital), a measure proportional to the binding potential (Bmax/Kd), was used for all comparisons. RESULTS: Results showed a statistically significant reduction in brainstem V3" values in depressed as compared to healthy subjects (3.1 +/- .9 vs. 3.8 +/- .8, p = .02). Platelet [3H]paroxetine binding was not altered (Bmax = 2389 +/- 484 vs. 2415 +/- 538 fmol/mg protein, p = .91) and was not significantly correlated with brainstem [123I] beta-CIT binding (r = -0.14, p = .48). CONCLUSIONS: These data are the first to suggest reductions in the density of brain SERT binding sites in living depressed patients. These findings provide further support for a preeminent role for alterations in serotonergic neurons in the pathophysiology of depression. 相似文献
184.
JP Rauschecker 《Canadian Metallurgical Quarterly》1998,3(2-3):86-103
Evidence from anatomical tracer studies as well as lesions of the primary auditory cortex (AI) indicate that the principal relay nucleus of the auditory thalamus, the ventral part of the medial geniculate (MGv), projects in parallel to AI and the rostral area on the supratemporal plane of the macaque monkey. The caudomedial area, by contrast, receives input from MGv only indirectly via AI, and neurons in this area are often tuned to the spatial location of a complex sound. The belt areas on the lateral surface of the superior temporal gyrus receive input from the primary areas. Neurons in these areas respond better to more complex stimuli, such as band-pass noise pulses of frequency-modulated sweeps, than to pure tones. Often neurons in the lateral belt respond well to species-specific communication calls. The hypothesis is put forward that the central auditory pathways in the macaque monkey are organized into parallel streams, similar to the visual system, one for the processing of spatial information, the other for the processing of auditory "patterns". Evidence from neuroimaging studies in humans with MRI and PET are consistent with this hypothesis. Virtual auditory space stimuli lead to selective activation of an inferior parietal region, whereas speech-like stimuli activate superior temporal regions. 相似文献
185.
K Trombitás M Greaser S Labeit JP Jin M Kellermayer M Helmes H Granzier 《Canadian Metallurgical Quarterly》1998,140(4):853-859
Titin (also known as connectin) is a giant protein that spans half of the striated muscle sarcomere. In the I-band titin extends as the sarcomere is stretched, developing what is known as passive force. The I-band region of titin contains tandem Ig segments (consisting of serially linked immunoglobulin-like domains) with the unique PEVK segment in between (Labeit, S., and B. Kolmerer. 1995. Science. 270:293-296). Although the tandem Ig and PEVK segments have been proposed to behave as stiff and compliant springs, respectively, precise experimental testing of the hypothesis is still needed. Here, sequence-specific antibodies were used to mark the ends of the tandem Ig and PEVK segments. By following the extension of the segments as a function of sarcomere length (SL), their respective contributions to titin's elastic behavior were established. In slack sarcomeres (approximately 2.0 micron) the tandem Ig and PEVK segments were contracted. Upon stretching sarcomeres from approximately 2.0 to 2.7 micron, the "contracted" tandem Ig segments straightened while their individual Ig domains remained folded. When sarcomeres were stretched beyond approximately 2.7 micron, the tandem Ig segments did not further extend, instead PEVK extension was now dominant. Modeling tandem Ig and PEVK segments as entropic springs with different bending rigidities (Kellermayer, M., S. Smith, H. Granzier, and C. Bustamante. 1997. Science. 276:1112-1116) indicated that in the physiological SL range (a) the Ig-like domains of the tandem Ig segments remain folded and (b) the PEVK segment behaves as a permanently unfolded polypeptide. Our model provides a molecular basis for the sequential extension of titin's different segments. Initially, the tandem Ig segments extend at low forces due to their high bending rigidity. Subsequently, extension of the PEVK segment occurs only upon reaching sufficiently high external forces due to its low bending rigidity. The serial linking of tandem Ig and PEVK segments with different bending rigidities provides a unique passive force-SL relation that is not achievable with a single elastic segment. 相似文献
186.
PL Giacalone F Laffargue JP Daurés I Lombard G Lombard 《Canadian Metallurgical Quarterly》1998,27(3):309-318
OBJECTIVE: Our purpose was to evaluate and compare the perioperative morbidity and the long-term results of the Raz colposuspension and the Bologna operation for the treatment of stress urinary incontinence in women. STUDY DESIGN: Data of 188 women who underwent either a Bologna operation (group 1) or a Raz colposuspension (group 2) for the treatment of stress urinary incontinence between January 1, 1987 and December 1, 1995 were analysed retrospectively regarding history, preoperative evaluation, associated surgical procedures, complications and cure and failure rate. POPULATION AND METHODS: 80 patients were treated with the Bologna operation and 108 with the Raz colposuspension. Patients with prior anti-incontinence surgery, and patients with a preoperative diagnosis of urge incontinence were excluded from the study. Success was defined both subjectively (complete absence of complaint of stress urinary incontinence) and objectively (no evidence of loss of urine on cough provocation during physical examination). Survival curves were generated in each group for time to event data: "time to recurrent stress incontinence" and compared by the logrank test. A multivariate analysis using a Cox proportional hazards regression model was performed to indentify possible outcome predictors. RESULTS: The success rate of group 1 was significantly higher than that of group 2 (p = 0.00001). The median of success was 51 months in group 1 and 21 months in group 2 (p = 0.00001). The incidence of intraoperative complications in each group (inadvertent cystostomy, hemorrhage) did not differ. The multivariate analyses using the Cox regression model showed that the most highly correlated variable with the surgical cure rate was the type of surgical anti-incontinence procedure adopted: Bologna or Raz (p = 0.00001) CONCLUSION: In our hands, the Bologna operation has a higher cure rate than the Raz colposuspension. For us, when treating patients with stress urinary incontinence by the vaginal route, the Bologna operation is indicated when sufficient anterior vaginal tissue is available to create vaginal bands. 相似文献
187.
JM Herbert JP Hérault A Bernat RG van Amsterdam JC Lormeau M Petitou C van Boeckel P Hoffmann DG Meuleman 《Canadian Metallurgical Quarterly》1998,91(11):4197-4205
SANORG 34006 is a new sulfated pentasaccharide obtained by chemical synthesis. It is an analog of the "synthetic pentasaccharide" (SR 90107/ ORG 31540) which represents the antithrombin (AT) binding site of heparin. SANORG 34006 showed a higher affinity to human AT than SR 90107/ORG 31540 (kd = 1.4 +/- 0.3 v 48 +/- 11 nmol/L), and it is a potent and selective catalyst of the inhibitory effect of AT on factor Xa (1,240 +/- 15 anti-factor Xa U/mg v 850 +/- 27 anti-factor Xa U/mg for SR 90107/ORG 31540). In vitro, SANORG 34006 inhibited thrombin generation occurring via both the extrinsic and intrinsic pathway. After intravenous (IV) or subcutaneous (SC) administration to rabbits, SANORG 34006 displayed a long-lasting anti-factor Xa activity and inhibition of thrombin generation (TG) ex vivo. SANORG 34006 was slowly eliminated after IV or SC administration to rats, rabbits, and baboons, showed exceptionally long half-lives (between 9.2 hours in rats and 61.9 hours in baboons), and revealed an SC bioavailability near 100%. SANORG 34006 displayed antithrombotic activity by virtue of its potentiation of the anti-factor Xa activity of AT. It strongly inhibited thrombus formation in experimental models of thromboplastin/stasis-induced venous thrombosis in rats (IV) and rabbits (SC) (ED50 values = 40.0 +/- 3.4 and 105.0 +/- 9.4 nmol/kg, respectively). The duration of its antithrombotic effects closely paralleled the ex vivo anti-factor Xa activity. SANORG 34006 enhanced rt-PA-induced thrombolysis and inhibited accretion of 125I-fibrinogen onto a preformed thrombus in the rabbit jugular vein suggesting that concomitant use of SANORG 34006 during rt-PA therapy might be helpful in facilitating thrombolysis and preventing fibrin accretion onto the thrombus under lysis. Contrary to standard heparin, SANORG 34006 did not enhance bleeding in a rabbit ear incision model at a dose that equals 10 times the antithrombotic ED50 in this species and, therefore, exhibited a favorable therapeutic index. We suggest that SANORG 34006 is a promising compound in the treatment and prevention of various thrombotic diseases. 相似文献
188.
The amphetamine derivative MDMA (3,4-methylenedioxymethamphetamine) was first synthesised in 1914 as an appetite suppressant, but was never used as such. MDMA is commonly known as "ecstasy" and has become a popular recreational drug of abuse at dance-clubs and rave parties, where it is combined with all-night dancing, crowded conditions, poor hydration and loud sound. This combination is probably the main reason why we have seen an upsurge in toxicity problems at rave parties, since all these factors are thought to promote or increase the toxicity of MDMA. The desired effects of MDMA are euphoria, increased energy and enhanced communication with others. Adverse effects are hyperthermia, rhabdomyolysis, acute renal failure, hepatotoxicity, depression and psychosis. 相似文献
189.
MATERIALS AND METHODS: In the period 1986-1994, 2950 patients with cardiovascular diseases were surgically treated. In 2104 cases we placed biological or synthetic grafts to maintain vascular continuity. The most common has turned out to be abdominal aortic aneurysm. We treated 783 cases in emergency conditions. Staging and localization of infection has been the first aim in patients with synthetic vascular grafts. We studied signs and symptoms related to infections. In all cases we discovered the microorganism responsible of infection we started antibiotic therapy. RESULTS: Surgical infection incidence is 4.9% (154 cases). Series analysis has evidenced a decrease in infection incidence in the period 1986-1994. The most frequent infections are: the urinary tract infection (59 cases, 38.5%) followed by surgical wound infection (37 cases, 24.1%), respiratory tract infection (27 cases, 17.5%), vascular graft infection (23 cases, 14.4%). All patients underwent a preoperative antibiotic prophylaxis with 2 degrees-3 degrees generation cephalosporines. We noted a higher graft infection incidence in patients treated with aortobifemoral reconstruction. We handled surgical infection following two main directions: 1-antibiotic therapy, 2-surgical treatment and antibiotic therapy. CONCLUSIONS: We noted surgical technique improvement and correct application of an antibiotic prophylaxis form has turned out to be the "gold standard" in order to reduce cardiovascular surgical infections. To reduce sepsis or graft infection we can work on either of the following: 1) antibiotic therapy; 2) operative time reduction; 3) try to limit vascular surgery in case of concomitant gastrointestinal surgical disease; 4) using alloplastic vascular grafts with high biological compliance; 5) patency time reduction of invasive diagnostic technique. 相似文献
190.
JM Warnecke JP Fürste WD Hardt VA Erdmann RK Hartmann 《Canadian Metallurgical Quarterly》1996,93(17):8924-8928
To study the cleavage mechanism of bacterial Nase P RNA, we have synthesized precursor tRNA substrates carrying a single Rp- or Sp-phosphorothioate modification at the RNase P cleavage site. Both the Sp- and the Rp-diastereomer reduced the rate of processing by Escherichia coli RNase P RNA at least 1000-fold under conditions where the chemical step is rate-limiting. The Rp-modification had no effect and the Sp-modification had a moderate effect on precursor tRNA ground state binding to RNase P RNA. Processing of the Rp-diastereomeric substrate was largely restored in the presence of the "thiophilic" Cd2+ as the only divalent metal ion, demonstrating direct metal ion coordination to the (pro)-Rp substituent at the cleavage site and arguing against a specific role for Mg(2+)-ions at the pro-Sp oxygen. For the Rp-diastereomeric substrate, Hill plot analysis revealed a cooperative dependence upon [Cd2+] of nH = 1.8, consistent with a two-metal ion mechanism. In the presence of the Sp-modification, neither Mn2+ nor Cd2+ was able to restore detectable cleavage at the canonical site. Instead, the ribozyme promotes cleavage at the neighboring unmodified phosphodiester with low efficiency. Dramatic inhibition of the chemical step by both the Rp- and Sp-phosphorothioate modification is unprecedented among known ribozymes and points to unique features of transition state geometry in the RNase P RNA-catalyzed reaction. 相似文献