It is well established that visual display unit (VDU) operators complain of visual fatigue and visual stress during after-work hours. The present study was divided into two parts. In the first part, standard eye examinations were performed on a group of VDU workers (n = 32) and a control group (n = 15); those subjects who were found to have correct vision (n = 16 and 13, respectively) participated in the second part. The eye examinations revealed that on the average, the VDU workers suffered more than twice as many visual impairments as the controls. In those with correct vision, the near point of accommodation was measured at the beginning of the workday at the start of the week, and at the end of the workday, four days later. In the VDU group, the decrease in accommodation was uniformally distributed between zero and 1.0 diopter, whereas among the non-VDU workers, 77% of the decrease was between zero and 0.25 diopter. The dynamic range of accommodation in the VDU workers on the second examination was smaller than on the first. We conclude that some of the visual stress and visual fatigue that developed at work hindered visual activities after work. 相似文献
BACKGROUND: The optimal time frame to improve the quality and cosmetic appearance of scars by laser therapy has not been clearly elucidated by prior controlled clinical trials. OBJECTIVE: To determine the efficacy of the 585-nm pulsed dye laser (PDL) in the treatment of surgical scars starting on the day of suture removal. METHODS: Eleven patients (skin types I-IV) with 12 postoperative linear scars that were greater than 2 cm were treated three times on monthly intervals with the 585-nm PDL (450 micro s, 10-mm spot size, 3.5 J/cm2 with 10% overlap) on one scar half, whereas the other half received no treatment. Scars were later evaluated by a blinded examiner using the Vancouver Scar Scale (VSS) for pigmentation, vascularity, pliability, and height. Scars were then blindly examined for cosmetic appearance using a visual analog scale. RESULTS: One month after the last treatment, final scar analysis by the blinded examiner revealed a significant difference between treated and untreated sites, with the treated halves scoring better in all scar parameters in the VSS and in cosmetic appearance. The treated halves demonstrated an overall average improvement in the VSS between the first treatment score and the final score of 54% versus 10% in the controls (P=0.0002). The cosmetic appearance score (0=worst; 10=best) at final assessment was significantly better for the treated scars, scoring 7.3 versus the averaged control score of 5.2 (P=0.016). CONCLUSION: The 585-nm PDL is effective and safe in improving the quality and cosmetic appearance of surgical scars in skin types I-IV starting on the day of suture removal. 相似文献
Background: Spherophakia is an uncommon diagnosis. This is the first case report of spherophakia evaluated by ultrasound biomicroscopy. Methods: Ultrasound biomicroscopy is a new diagnostic technique developed by one of the authors and provides images with microscopic resolution of the anterior segment. A patient with spherophakia was evaluated by ultrasound biomicroscopy (Zeiss-Humphrey, 50MHz) before and after YAG laser iridotomy. Results: Ultrasound biomicroscopic assessment revealed a shallow anterior chamber, a very steep anterior lens curvature, iridolenticular contact, elongated zonules, and an increased distance between the lens equator and the ciliary processes. Angle closure glaucoma was due to a pupil block mechanism. The pupil block was relieved by YAG laser iridotomy. Conclusions: Ultrasound biomicroscopy is a useful technique to confirm the diagnosis of spherophakia. The pupil block in spherophakia is relieved by YAG laser iridotomy. 相似文献
Occupational exposure to HIV is becoming a daily hazard in many emergency departments. Emergency physicians who are protected by disability insurance policies are likely to believe that if they are unable to continue working because of HIV-positive status, their disability policies will provide them with a source of income. Unfortunately, analysis of case law regarding claims under disability policies shows that the law is unlikely to consider an asymptomatic, HIV-positive physician disabled for purposes of payments under disability policies. Therefore, it is necessary for emergency physicians to make sure this issue is resolved before buying and relying on a disability policy so that an anticipated safety net will be operative over the full range of hazards that emergency physicians face.[Lavely R: The HIV-positive physician and disability insurance. Ann Emerg Med June 1994;23:1355-1362.] 相似文献
Confidentiality is a promise rooted in tradition, law andmedical ethics. Emergency physicians treat a variety of patients to whom confidentiality is of vital importance: employees, celebrities, victims of violence or disaster, minors, students, criminals, drug abusers, and patients with STDs. EDs should develop methods of ensuring confidentiality for all patients.34Although confidentiality is an important principle thatshould be respected and guarded, it is not absolute. Various laws mandate disclosure of certain patient information; in addition, an overriding moral duty may occasionally require, a breach of confidentiality. As Beauchamp and Childress noted, “the therapeutic role may sometimes have to yield to ones role as citizen and as protector of the interests of others”.19 In general, however, circumstances requiring a breach of confidentiality are rare. 相似文献
A method of electroretinogram c-wave recording in the rat was developed that uses a contact lens electrode connected through a saline bridge with a silver-silver chloride half-cell. A cluster of light-emitting diodes, regulated by an electronic light-emitting diode stimulator, was used as a light source. The method enables recordings of c-waves of 0.4–1.6 mV amplitude as well as other electroretinogram components in narrow limits of variation. The two main sources of response variability are voltage shunting and eyeball protrusion. 相似文献
Background: Data concerning chest wall configuration and the activities of the major respiratory muscles that determine this configuration during anesthesia in humans are limited. The aim of this study was to determine the effects of halothane anesthesia on respiratory muscle activity and chest wall shape and motion during spontaneous breathing.
Methods: Six human subjects were studied while awake and during 1 MAC halothane anesthesia. Respiratory muscle activity was measured using fine-wire electromyography electrodes. Chest wall configuration was determined using images of the thorax obtained by three-dimensional fast computed tomography. Tidal changes in gas volume were measured by integrating respiratory gas flow, and the functional residual capacity was measured by a nitrogen dilution technique.
Results: While awake, ribcage expansion was responsible for 25 plus/minus 4% (mean plus/minus SE) of the total change in thoracic volume (Delta Vth) during inspiration. Phasic inspiratory activity was regularly present in the diaphragm and parasternal intercostal muscles. Halothane anesthesia (1 MAC) abolished activity in the parasternal intercostal muscles and increased phasic expiratory activity in the abdominal muscles and lateral ribcage muscles. However, halothane did not significantly change the ribcage contribution to Delta Vth (18 plus/minus 4%). Intrathoracic blood volume, measured by comparing changes in total thoracic volume and gas volume, increased significantly during inspiration both while awake and while anesthetized (by approximately 20% of Delta Vth, P < 0.05). Halothane anesthesia significantly reduced the functional residual capacity (by 258 plus/minus 78 ml), primarily via an inward motion of the end-expiratory position of the ribcage. Although the diaphragm consistently changed shape, with a cephalad displacement of posterior regions and a caudad displacement of anterior regions, the diaphragm did not consistently contribute to the reduction in the functional residual capacity. Halothane anesthesia consistently increased the curvature of the thoracic spine measured in the sagittal plane. 相似文献
Bone disorders following gastrectomy were studied by measuring absolute and relative bone mineral density of the Wards triangle, serum 1,25-(OH)2-D, alkaline phosphatase, and total serum calcium. The subjects were 20 males who had undergone total gastrectomy not more than three months previously (group A1). Seventeen of these patients were reviewed three years later (group A2). Absolute and relative bone density were significantly lower in group A2 than in A1 (0.52 ± 0.011 g/cm2 versus 0.6 ± 0.014 g/cm2,P<0.01 and 85.5 ± 1.4% age-matched control versus 95 ± 1.3%,P<0.01). 1,25-(OH)2-D was significantly lower in group A2 than in group A1 (14.3 ± 0.97 pg/ml versus 20.6 ± 1.02 pg/ml,P<0.01). There was no difference in alkaline phosphatase and calcium serum concentration. The mean weight loss was 6.26 ± 0.57% over the follow-up period, and weight loss correlated with absolute and relative bone density (r=–0.74,P<0.01). There was a positive correlation between 1,25-(OH)2-D and absolute or relative bone density (r=0.67,r=0.62 andP<0.01). These data suggest that bone density decrease has already occurred three years after total gastrectomy and is positively correlated to 1,25-(OH)2-D deficiency. As no differences in serum alkaline phosphatase and serum calcium concentration were found, these factors are of little value for the early detection of postgastrectomy bone disorders, whereas weight loss is a valuable screening parameter. 相似文献