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Purpose: The purpose of this study was to assess noncarious cervical lesions in young patients and to establish a possible relation with occlusal aspects.
Materials and Methods: Forty-eight dental students (28 males; 20 females) between the ages of 16 and 24 years, were investigated to verify the presence of noncarious cervical lesions and their relation to some occlusal aspects. The assessment involved a questionnaire, clinical examinations, and model analysis.
Results: The results indicated that the lower first molars (21.3%), the upper first molars (16.0%), the upper first premolars (12.8%), the lower first premolars (11.7%), and the lower second premolars (11.7%) were the teeth most affected by the lesions. Age was a significant factor with respect to the presence of lesions; the students with noncarious cervical lesions were older than the students who showed no lesions. Among the 79 teeth exhibiting lesions, 62 (78.5%) showed wear facets. In the group with lesions, the mean, per subject, was 15.0 teeth with wear facets, whereas in the group without lesions the mean was 10.8 teeth with wear facets per subject, suggesting that occlusal stress has some effect on lesion development.
CLINICAL SIGNIFICANCE
Noncarious cervical lesions are characterized by loss of tooth structure on the cervical area of the tooth and can result in esthetic problems for the patient, as well as discomfort due to the hyper-sensibility that often occurs at the location of the lesion. The results obtained reinforce the multifactorial theory, shared by several authors, for the etiology of such lesions. However, as the limitations of each etiologic agent begin to be understood, there will be a decrease in the possibility of misleading interpretations of the result of present or future investigations.  相似文献   
13.
N α-Dithiasuccinoyl (Dts) amino acids ( 1 ) needed for solid-phase peptide synthesis have been prepared in good yields and excellent purities by a new method that exploits the solubility properties of polyethylene glycol (PEG; bifunctional with average molecular weight 2000 was found to be optimal). Suitably side-chain protected amino acid derivatives are first reacted with a polymeric xanthate ( 11 ), following which the free α-carboxyl is blocked by silylation and the Dts heterocycle is elaborated in the same pot by reaction with chlorocarbonylsulfenyl chloride ( 4 ). Upon aqueous workup, the polymeric carrier removes any urethane blocked amino acids which arise during the process. Exaggerated conditions were explored to prove the power of this functional purification approach, and mechanisms of formation of polymer-bound urethanes are proposed and supported by solution model studies. The preparation and characterization of the companion N-(iso-propyldithio)carbonyl derivative of proline is also presented.  相似文献   
14.
Common atrial flutter is due to a macroreentry circuit in the right atrium, but the cranial path of the circuit has not been defined. The objectives of this article are to determine the cranial turning point of flutter activation in relation to a hypothetic obstacle, the superior vena cava opening, by examining the changes in activation sequence produced by entrainment from different points. In 13 cases of common atrial flutter with typical counter-clockwise right atrial circuits confirmed by endocardial mapping the atrium was paced from the high posterior and mid-septal walls. Entrainment was confirmed by simultaneous recordings of 6–7 right atrial electrograms. Changes in sequence of electrograms from high septum and high anterolateral walls was sought. Electrogram sequence and morphology did not change with entrainment at the posterior wall with respect to the basal flutter or mid-septal wall entrainment. Pacing "below" the superior vena cava did not advance the anterior wall electrogram in relation to the septal electrogram. These findings suppport the concept that common Putter activation turned around (cranial and anterior to) the superior vena cava opening, and not around the free end of a line of block below the superior vena cava in the posterior wall. Common atrial flutter activation rotates cranial (and anterior) to the superior vena cava opening, through the "right atrial roof" The line of functional block should span from inferior to superior vena cava openings.  相似文献   
15.
The few studies that have examined the association between usual sleep duration and cognitive function have shown conflicting results. This cross‐sectional study examined the association between sleep duration and cognitive function among 3212 people, representative of the non‐institutionalized population aged 60 years and over in Spain. Sleep duration was self‐reported, and cognitive function was measured with the Mini‐Examen Cognoscitivo (MEC), a version of the Mini‐Mental State Examination that has been validated in Spain. Linear regression, with adjustment for the main confounders, was used to obtain mean differences in the MEC between the categories of sleep duration (≤5, 6, 7, 8, 9, 10, ≥11 h day?1). The MEC score decreased progressively (became worse) across sleep categories from 7 to ≥11 h (P for linear trend <0.001). People who slept for ≥11 h had a significantly lower MEC score than those who slept for 7 h (mean difference ?1.48; 95% confidence interval ?2.12 to ?0.85). This difference in the MEC was similar to that observed for a 10‐year increase in age. The results did not vary significantly by sex (P for interaction >0.05). No association was observed between short sleep duration (<7 h) and cognitive function. We conclude that long sleep duration is associated with poorer cognitive function in older adults from the general population.  相似文献   
16.
Embolic phenomena are associated with endocarditis. We report a patient suffering from infective endocarditis, in which the exact moment of detachment of an aortic valve vegetation and subsequent embolization was eyewitnessed during two-dimensional echocardiography, and the entire episode was recorded on video tape.  相似文献   
17.
PROBLEM: The structure and protective activity of antibodies against tetanus (anti-T) and diphtheria (anti-D), produced during human pregnancy and transferred to new-born, was studied. METHOD: Antibody levels were measured by ELISA in non-pregnant women (control group), primiparae, and multiparae, and in their children. The proportion of symmetric and asymmetric IgG molecules was determined and their respective protective capacity evaluated. RESULTS: The quantity of asymmetric anti-T and anti-D antibodies in mothers at the time of delivery was roughly four- and three-fold that of the control group, respectively, dropping significantly 1 month later. A similar proportion of these antibodies was observed in the new-born. The lower neutralizing capacity of asymmetric molecules was demonstrated in vivo. CONCLUSION: Results show that during pregnancy there is a modulation of the immune response with an increase in the production of asymmetric molecules of lower protective capacity.  相似文献   
18.
Background: Severe mitral regurgitation induces reversal of flow in the pulmonary veins. We hypothesized that severe tricuspid regurgitation may disrupt normal coronary sinus flow. The purpose of this study was to analyze the Doppler flow pattern of the coronary sinus and to determine its value in the assessment of the severity of tricuspid regurgitation. Methods: The coronary sinus flow was analyzed in 70 consecutive patients with some degree of tricuspid regurgitation (27 mild, 14 moderate, and 29 severe) and in 35 patients without tricuspid regurgitation. The coronary sinus flow was obtained by pulsed-Doppler transesophageal echocardiography in a transverse plane, which showed its drainage into the right atrium. Results: The number of patients with adequate studies of the coronary sinus tended to increase with the severity of the tricuspid regurgitation. In patients without or with only mild tricuspid regurgitation the coronary sinus Doppler flow pattern was formed by two negative waves, a late systolic wave and another diastolic one with higher velocity and longer duration. The systolic wave became reversed in 21 (96%) of the patients with severe tricuspid regurgitation. The sensitivity, specificity, and diagnostic accuracy of the presence of a reversed systolic wave in the coronary sinus for the diagnosis of severe tricuspid regurgitation was 95%, 82%, and 80%, respectively. Conclusions: Significant tricuspid regurgitation modifies the coronary sinus flow pattern as assessed by transesophageal echocardiography. The presence of a reversed systolic flow in the coronary sinus appears to be a reliable new sign with good sensitivity, specificity, and diagnostic accuracy for the diagnosis of severe tricuspid regurgitation .  相似文献   
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In order to determine the activity of paclitaxel in patients with relapsed or refractory non-Hodgkin's lymphoma (NHL), we conducted a phase II clinical trial in which eligible patients received paclitaxel 200 mg/m2 intravenously over 3 h. Treatment was repeated every 3 weeks. Patients achieving complete or partial responses after two courses of paclitaxel continued to receive therapy for a maximum of eight courses, otherwise they were removed from the study. Of 96 evaluable patients, 45 (47%) had primary refractory disease, and 51 (53%) had relapsed lymphoma. The median number of prior treatment regimens was two (range one to 10 regimens). 45 patients had low-grade, 44 had intermediate-grade, and seven had mantle cell lymphoma. 24/96 patients responded (10 complete and 14 partial remissions) for an overall response rate of 25% (95% CI 17–35%). Patients with relapsed lymphoma had a higher response rate than those with primary refractory disease (19/51=37% v 5/45 =11%; P  < 0.01), and patients with relapsed intermediate-grade lymphoma had a higher response than those with relapsed low-grade lymphoma (9/18=50% v 10/31 = 32%; P  = 0.22). The treatment was very well tolerated with the most common side-effects being alopecia (100%), peripheral neuropathy (35% of ≥ grade II), and arthralgia/myalgia (25% of ≥ grade II). After the first course of paclitaxel, grade III/IV thrombocytopenia and neutropenia were observed in 21% and 23% of the patients respectively. 23 episodes of neutropenic fever developed after 250 courses of paclitaxel therapy (8%). We conclude that paclitaxel, at this dose and schedule, is an active new drug for the treatment of non-Hodgkin's lymphoma. The activity of paclitaxel combination programmes are currently under investigation.  相似文献   
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