首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
BACKGROUND: A retinal image performance distorted by an asymmetric or irregular corneal surface cannot be compensated for with spherocylindric glasses completely. The best-corrected visual acuity is markedly decreased and contact lens fitting often impossible. The purpose of this study was to calculate the differential height between corneal topography raw data and any regular surface with mathematical methods in order to ablate the differential height with a computer-controlled laser beam, thereafter. METHODS: A Zernike decomposition of radial degree n = 16 was realized within a clinically relevant central corneal area of 8 mm in diameter based on corneal topography raw height data of a commercially available topographer (TMS-1, Tomey, Erlangen). Any target surface could be defined by varying weighting of the Zernike coefficients. The calculated differential height ablation between the raw data and the target surface given in a polar grid was transformed to a Cartesian grid to evaluate the sleeping time at each grid position considering the characteristic ablation curve for the intended ablation of the height difference. Subsequently, differential height ablation was simulated using an automated laser beam control for a modified excimer laser (MEL60, Aesculap-Meditec, Jena). We developed software tools for Zernike decomposition of corneal topography raw height data and time-regulated automatic laser beam control of the grid positions in the higher programming language C (Borland C++ 3.1, Borland Inc., München). RESULTS: Definition of a target surface can be realized alternatively by selecting a set of Zernike coefficients or defining a spherical or spherocylindrical surface by superposition of parabolic terms in a fixed proportion creating a best-fit target surface to the raw data. In originally "relatively flat" areas, the differential height profile indicates a "relatively deep" ablation resulting in relative steepening towards the periphery of the ablation zone. The resolution of the mechanical unit of the laser beam control consisting of two linear stepping motors is 9 microns in the focal plane with a reproducibility of 5 microns. The software unit is guiding the laser beam in a meandering fashion within the ablation area considering the calculated sleeping time for each grid position. Mean overlap of the 1 mm laser spots is 70%. The laser beam diameter of 1 mm effects a peripheral transition zone of 0.5 mm. CONCLUSIONS: Zernike decomposition of corneal topography height data is an efficient tool for localizing and quantifying superficial irregularities and for directly calculating an ablation profile from created differential height data. With an automatic laser beam control a well-defined laser ablation of superficial corneal irregularities is possible, subsequently.  相似文献   

2.
BACKGROUND: High recovery rates of continence are observed after surgical procedures for rectal prolapse. Increases in rectal compliance but no obvious rise in anal pressures have been reported. The authors' hypothesis was that decreased rectal adaptation to distension may contribute to incontinence in patients suffering from overt rectal prolapse. METHODS: This was a prospective study conducted in 20 consecutive incontinent patients suffering from overt rectal prolapse with no mucosal change (two men and 18 women; mean(s.e.m.) age 50(3) years). They were compared with 20 age- and sex-matched patients with incontinence without rectal prolapse and ten age- and sex-matched healthy volunteers observed during the same period. The subjects were submitted to phasic isobaric distension of the rectum with an electronic barostat. Anal pressures, perception scores and rectal volumes were recorded at six different preselected pressures. RESULTS: Compared with healthy subjects, maximum rectal volumes (mean(s.e.m) 98(6) versus 167(11) ml; P= 0.005), volumes related to compliance (56(5) versus 100(9) ml; P= 0.004) and tone (41(3) versus 67(4) ml; P = 0.003) were decreased significantly in the rectal prolapse group. Prolapse and incontinence groups did not differ significantly with respect to rectal adaptation for all three parameters and steps of distension considered. CONCLUSION: Patients suffering from overt rectal prolapse had markedly impaired rectal adaptation to distension which may contribute to incontinence.  相似文献   

3.
BACKGROUND: Laparoscopy is gaining an important role in the treatment of benign colorectal disorders. The aim of this study is the evaluation of clinical and functional results in 4 patients submitted to a laparoscopy rectopexy according to Wells. METHODS: Four females (22-76, mean 53.7 years) affected from a total rectal prolapse with fecal incontinence underwent this procedure from 1993 through 1995. Six months after surgery, at the end of a rehabilitation program consisting of kinesitherapy, bio-feedback and electrostimulations, all patients have been re-evaluated by means of a clinical exam, anorectal manometry, defecography. RESULTS AND CONCLUSIONS: Preliminary results seem satisfactory and may allow to prefer this approach instead of the traditional open one.  相似文献   

4.
Patients with obstructed defaecation (OD) perform major defaecatory efforts that lead progressively to pudendal motor neuropathy. Anorectal sensory function in these patients and its possible influence in the pathogenesis of the disease have been little studied. In the present paper we investigated anorectal sensitivity to electric and thermal stimuli in patients with OD, and studied the possible existence of pudendal sensory neuropathy associated to their known pudendal motor neuropathy. Forty subjects were divided into two groups: 21 healthy controls (11 females and 10 males; mean age 51.8 +/- 11 years, range 33-67) and 19 patients with OD (18 females and 1 male; mean age 48 +/- 15 years, range 20-71). The patients with OD suffered constipation and an obstruction sensation upon defaecating, even in the case of soft stools. Clinical perineometry, manometry, pudendal motor latency studies, external anal sphincter single fibre electromyography and the evaluation of sensitivity to electric and thermal stimuli were carried out in all cases. All pudendal motor function parameters showed statistically significant differences between the two groups. In the controls the electrical sensitivity threshold was minimal in the mid anal canal, where sensory receptor presence is greater. Sensitivity was significantly higher in the upper and lower anal canal regions (P < 0.05), and much higher in the rectum (P < 0.001). A similar sensory profile was recorded in the patients with OD, though with significantly higher thresholds at all points with respect to the controls. The thermal stimulus thresholds in the lower and middle anal canal were significantly smaller than in the upper canal region and rectum, and the thresholds were again higher among the patients with OD than among the controls. In all cases the thresholds for heat were lower than for cold stimuli. In both groups the motor function parameters were correlated with the sensory function variables, and the latter between themselves. Patients with OD presented sensory deterioration at all points studied in the anal canal and rectum. Sensory pudendal neuropathy was found to be associated with the pudental motor neuropathy.  相似文献   

5.
6.
Objective: Recent research has documented increased psychosocial difficulties in individuals who report higher-than-typical autistic traits but without an Autism Spectrum Disorder (ASD) diagnosis. Less is known, however, regarding the cognitive profile of individuals with subthreshold autism symptomatology. The objective of the present study was to provide additional insight into this issue and examine whether young adults who report higher degrees of autism traits also report experiencing increased difficulties with executive control. Method: The Behavior Rating Inventory of Executive Function was utilized to evaluate behavioral aspects of executive functioning in 66 and 28 individuals who endorsed high and low subthreshold levels of autism symptomatology, respectively. Results: After accounting for Attention Deficit/Hyperactivity Disorder (ADHD) symptomatology at both the group and individual participant levels, we found that autism traits continued to explain a significant amount of variance in participants' overall level of executive function (Global Executive Composite) as well as within most individual executive domains. Interestingly, the high and low trait groups did not differ on the inhibitory control and organization of materials scales, areas of functioning that appears to be largely spared in individuals with ASD as well. Conclusions: Findings from the present study are consistent with past research linking ASD and executive control impairment. In addition, ASD and ADHD traits were associated with unique contributions to the executive control profile of individuals with subthreshold autism symptomatology. This finding underscores the importance of accounting for ADHD symptomatology in studying ASD. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

7.
Investigated the recognition of, and responses to, facial expressions of emotion. Ss were all women and consisted of the following groups: (1) 16 depressed college students, (2) 16 nondepressed college students, (3) 16 depressed psychiatric patients, and (4) 11 nondepressed psychiatric patients. Results suggest that both depressed groups, relative to the nondepressed college group, made more errors in recognizing the facial expressions and reported more freezing or tensing, higher fear and depression reactions, and less comfort with their own emotional reactions to these expressions and a stronger desire to change these reactions. Few differences were found between the depressed psychiatric patients and the psychiatric control Ss. It is concluded that inappropriate reactions to others' emotions may maintain or increase depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

8.
BACKGROUND: Methotrexate is readily absorbed from the intestinal tract. When given to patients with urinary diversion to the intestinal tract, methotrexate may be reabsorbed into the circulation, thus increasing its serum concentration and potentially increasing its toxicity. METHODS: Forty-eight patients with transitional cell carcinoma of the urinary tract who had undergone cystectomy and either an ileal conduit or a continent diversion were evaluated for their tolerance of chemotherapy. Of the 42 evaluable patients, 23 had a continent diversion and 19 had an ileal conduit. None of the patients with the continent diversion had an indwelling Foley catheter during the course of chemotherapy. RESULTS: There were no statistically significant differences in incidence of fever or neutropenia, mucositis, dose modification, or delay in chemotherapy between the two groups. When compared with a group of patients with native bladders who received the same chemotherapy, patients with continent diversions did not have increased incidence or severe toxicity from chemotherapy. CONCLUSIONS: Patients with continent diversions tolerated chemotherapy as well as patients with ileal conduits.  相似文献   

9.
FT Huber  H Stein  JR Siewert 《Canadian Metallurgical Quarterly》1995,19(1):138-43; discussion 143
Constipation and incontinence are frequent complications of rectal prolapse. Surgery should not only aim to correct prolapse but also improve bowel and sphincter function. From 1986-1991 42 patients with procidentia were treated by rectopexy and sigmoid resection. The mean age was 61.1 years. Thirty-nine patients were available for follow-up examination. Mean follow-up was 54 months. Functional data were collected prospectively before the operation and at follow-up and included clinical parameters, a constipation score, an incontinence score, anal manometry [mean resting pressure (MRP), mean maximum pressure (MMP)], proctography [anorectal angle (ARA)] and colonic transit studies [mean transit time (MTT), rectosigmoid transit time (RSTT)]. The postoperative complication rate was 7.1% (n = 3), mortality was 0%. No recurrence was seen. Constipation complaints improved from 43.6% to 25.6% (p < 0.001) and incontinence from 66.6% to 23.1% (p < 0.001). MRP increased from 36.5 mmHg to 46.0 mmHg and MMP from 90.5 mmHg to 103.0 mmHg (p < 0.001). ARA changed from 102 to 98 degrees (p < 0.001) and correlated with sphincter tone and continence. MTT decreased from 47.8 to 38.5 hours, segmental transit (RSTT) from 21.1 to 12.7 hours (p < 0.001). Our results indicate that rectopexy with sigmoid resection is a safe and effective procedure for rectal prolapse and improves functional disorders of bowel and sphincter.  相似文献   

10.
BACKGROUND/AIM: Quantitative measurement of hepatic iron by biochemical analysis of liver biopsy samples is required to assess hepatic iron stores accurately. Cirrhotic livers, however, contain variable amounts of fibrous tissue and the distribution of iron within the hepatic parenchyma is not always uniform. The aim of this study was to assess the variability in hepatic iron concentration measurement from needle-biopsy specimens. METHODS: The livers from eight patients with cirrhosis selected because of elevated serum ferritin were obtained at the time of liver transplantation (n = 6) or at autopsy (n = 2). Multiple needle biopsies were done, and hepatic iron concentration was measured by atomic absorption spectroscopy. The hepatic iron index was calculated as iron concentration divided by age. RESULTS: Four cases had a mean hepatic iron index above 2.0, in the range of that reported in patients with homozygous genetic hemochromatosis, whereas the other four had an hepatic iron index of less than 2.0. The intra-individual coefficient of variation for hepatic iron concentration ranged from 11.3 to 43.7%, averaging 24.9%. The coefficient of variation was smaller in biopsy samples > 4 mg dry weight than in samples < 4 mg (19.8% vs 28.6%, p < 0.05). Histological examination of surgical biopsies from these livers showed large amounts of fibrous tissue, and inhomogeneous distribution or iron in the hepatic parenchyma. CONCLUSIONS: This study demonstrates an important variability in the measurement of hepatic iron content from needle biopsy specimens in patients with severe cirrhosis.  相似文献   

11.
Of sixty patients with chronic liver disease, eight with cirrhosis or chronic hepatitis had very low serum CH50 but normal plasma CH50. The complement component profiles of these sera revealed markedly decreased C4 and C2 activities and normal C3T (C3-C9) activities. From these results, it is suggested that the early acting complement components had been non-specifically activated during blood coagulation in these patients. No difference between plasma and serum CH50 was found in patients with hepatitis B(s) antigen.  相似文献   

12.
The neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP) is present in many regions of the adult and developing brain as are receptors for PACAP. PACAP stimulates different signalling cascades in neurons, involving cAMP, MAP kinase, and calcium. These characteristics suggest that PACAP may influence neuronal development. Here we have studied the effects of PACAP on mesencephalic dopaminergic neurons using primary cultures from embryonic rats. PACAP increased the number of tyrosine hydroxylase (TH)-immunoreactive neurons, elevated TH protein, and enhanced tritiated dopamine uptake in these cultures. Moreover, PACAP counteracted the effects of 6-hydroxydopamine treatments, which induce cell death of dopaminergic neurons. In situ hybridisation showed that both PACAP and PACAP receptor type 1 are present in developing and adult rat mesencephalon. These results show that PACAP has a neurotrophic action on dopaminergic neurons and partially protects them against 6-OHDA induced neurotoxicity.  相似文献   

13.
The objectives of this study were to detect differences in the Doppler power backscattered by blood in vivo, and to identify factors affecting the backscattered power. The main hypothesis was that variations in the erythrocyte aggregation level between veins and arteries of normolipidemic and hyperlipidemic individuals can be detected with power Doppler ultrasound. Doppler measurements were performed at 5 MHz, with an Acuson 128 XP/10 system, over the carotid artery and jugular vein, external iliac artery and vein, common femoral artery and vein and popliteal artery and vein. Doppler signals were recorded at the center of each vessel to optimize the detection of erythrocyte aggregation, and processed off-line to obtain the backscattered power. The power of each recording was compensated for Doppler gain differences, tissue attenuation with depth and transmitted power variations occurring with pulse-repetition interval modifications. Results showed statistically stronger backscattered power in veins compared to arteries for the iliac, femoral and popliteal sites. In comparison with healthy subjects, stronger powers were observed in hyperlipidemic patients for the femoral and popliteal sites. Power differences were also found between peripheral measurements. On the other hand, no difference was observed between the power measured in the carotid artery and jugular vein for both groups of individuals. Multiple linear regression analyses were performed to identify factors affecting the backscattered power. Results showed a correlation (r) of 71.2% between the Doppler power in the femoral vein and the linear combination of two parameters: an erythrocyte aggregation index S10 measured with a laser scattering method, and the diameter of the vessel measured on B-mode images. Statistically significant linear correlation levels were also found between S10 and the Doppler power in various vessels. In conclusion, this study showed that power Doppler differences exist in vivo in large vessels between veins and arteries of normolipidemic and hyperlipidemic individuals. The Doppler power variations were also shown to be related to erythrocyte aggregation.  相似文献   

14.
Gave 18 white male hospitalized patients from each of 3 diagnostic categories (brain-damaged, schizophrenic, and medical) a battery of 9 psychological tests, including 5 from the Halstead Impairment Index, the Bender Visual-Motor Gestalt Test, the Trail Making Test (R. Reitan), and 2 tests from the WAIS. 16 measures were obtained, and the 3 groups of Ss were compared on each. The performance of the brain-damaged was significantly inferior to the medical patients on 14 of the 16 measures, and to the schizophrenics on 9 of the 16. There were no significant differences between the schizophrenics and the medical group on any of the 16 measures. When the scores on the 4 different tests were combined into Z scores, 78% of the brain-damaged, 67% of the schizophrenics, and 78% of the medical Ss were correctly diagnosed for presence or absence of brain damage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

15.
Small fibrin-platelet emboli caused by prolapsed mitral valves may cause retinal occlusive disease with a wide range of ophthalmic manifestations, including amaurosis fugax in young people, retinal or choroidal arteriolar occlusion, and retinal neovascularization (atypical Eales' disease). Six patients with retinal occusive disease underwent extensive noninvasive cardiac and systemic tests and were found to have prolapsed mitral valves. Patients with unexplained ocular emboli should be examined by a cardiologist for possible mitral valve prolapse.  相似文献   

16.
Postural control in the sagittal plane was evaluated in 22 patients with chronic anterior cruciate ligament (ACL) deficiency and the result was compared to that of a control group of 20 uninjured subjects. Measurement of the body sway was done on a fixed and sway-referenced force plate in both single-limb and two-limb stance, with the eyes open and closed, respectively. Further, an analysis of the postural reactions to perturbations backwards and forwards, respectively, was made in single-limb stance. The results demonstrated statistically significant deficits of the postural control in the patient group compared to the control group, but also within the patient group. There was a significantly higher body sway within the patient group when standing on a stable support surface on the injured limb than standing on the uninjured limb with the eyes open, but no difference with the eyes closed. When standing on a stable support surface, there was a significantly higher body sway in the patient group standing on the injured leg than in the control group, both with eyes open and closed. The patient group also showed a significantly impaired postural control compared to the control group when standing on the uninjured leg with the eyes closed. There was no difference between the groups in the two-limb stance. When standing on the sway-referenced support surface, the patient group had a significantly larger body sway than the control group when the eyes were open, but there was no significant difference between the groups with the eyes closed. The measurement of the postural corrective responses to perturbations backwards and forwards showed that the reaction time measured from the initiation of the force plate translation, and the amplitude of the body sway was significantly greater in the patient group than in the control group. We conclude that patients with a continuing chronic ACL insufficiency several years after injury have an impaired postural control in the antero-posterior direction in single-limb stance on their injured leg. They also show a greater body sway and a prolonged reaction time when subjected to antero-posterior perturbations when standing on their injured leg.  相似文献   

17.
We empirically examined S. H. Budman and A. S. Gurman's (see record 1984-04498-001) theoretical proposals concerning major differences in the value systems of long- vs. short-term therapists. Ss were 222 randomly selected licensed psychologists who indicated their preferred approach (short-term or long-term). Values were assessed with a scale designed for the study. Overall, results indicate that therapists who prefer a short-term approach are more likely to endorse the proposed values of the short-term therapist than are therapists who prefer a long-term approach. This finding held even after the authors controlled for the significant contributions of theoretical orientation and therapeutic practice variables. Specifically, short-term (vs. long-term) therapists believed more that psychological change could occur outside of therapy and that setting time limits would intensify the therapeutic work. Implications for the practice of brief therapy are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

18.
The present study concerns the relation between properties of personality traits and the agreement with which they are applied to real individuals. Subjects rated the 100 personality items of the California Q-Set on nine subjective dimensions, six of which loaded highly on a first principal component. This factor was interpreted as reflecting each trait's "easy visibility" to an outside observer. Actual interjudge agreement in applying each trait to real individuals was assessed in two ways: Self–other agreement was assessed in two independent samples, and interpeer agreement was assessed in three samples. Impressive and stable agreement was found for most Q items. The traits that were applied to individuals with the greatest interjudge agreement were the same ones that seemed most easily visible and tended to be positively relevant to extraversion and negatively relevant to neuroticism (identified through a factor analysis by McCrae, Costa, & Busch, 1986). The results suggest (a) that traits defining extraversion are revealed relatively directly in social behavior and, therefore, are easy to judge, (b) that traits defining neuroticism are less visible and, so, are judged less accurately, and (c) that lay perceivers of personality are generally sensitive to this difference between traits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

19.
Assessment of posture is an integral component of patient evaluation with shoulder overuse injuries. However, the professional literature contains relatively few studies that have assessed the relationship between posture, function, and injury. The purpose of this study was to determine the relationship and differences in postural variables within and between subjects with overuse injuries to the shoulder of healthy subjects. Thirty patient subjects and 30 healthy subjects matched for age and gender were recruited. Scapular protraction and rotation, forward head position, midthoracic curvature, and passive humeral elevation in the plane of the scapula were measured randomly in standing. All measurement techniques were standardized and validated. Intrarater and interrater reliability for all clinical measures were established before data collection. Forward head position was significantly greater (p < .001) in the patient group than the healthy group; humeral elevation was significantly greater (p < .001) in the healthy group than in the patient group and in the uninvolved shoulders (p < .01) than the involved shoulders within the patient group. Scapular protraction, rotation, midthoracic curvature, and scapular symmetry were not significantly different between groups. Scapula protraction and rotation were significantly related (p < .05) in the patient group. No other postural variables were related. Conclusions regarding the influence of posture to shoulder injury are inconclusive based on several confounding variables that may have affected the outcome.  相似文献   

20.
This study investigated age changes in risk perception and unrealistic optimism. Teenagers (n?=?376) and parents (n?=?160) evaluated the risk of experimental, occasional, and regular involvement in 14 health-related activities (e.g., getting drunk). Respondents also evaluated their comparative chances of encountering the leading causes of morbidity and mortality. Compared with adults, teenagers minimized the perceived risk of experimental and occasional involvement in health-threatening activities. Notably, teenagers were less optimistic about avoiding injury and illness than were their parents, and teenagers at greatest risk for such misfortunes were the least optimistic about avoiding them. These findings do not support traditional explanations of adolescent risk taking. The implications of these findings for understanding and preventing health-damaging behavior among adolescents are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号