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Although the role of memory in visual search is debatable, most researchers agree with a limited-capacity model of memory in visual search. The authors demonstrate the role of memory by replicating previous findings showing that visual search is biased away from old items (previously examined items) and toward new items (nonexamined items). Furthermore, the authors examined the type of memory representations used to bias search by changing an item's individuating feature or location during search. Changing the individuating feature of an item did not disrupt normal search biases. However, when the location of an item changed, normal search biases were disrupted. These results suggest that memory used in visual search is based on items' locations rather than their identity. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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Expression of fusion proteins between prepro-alpha-factor and somatostatin (SRIF) in yeast, resulted in the correct processing and secretion of the heterologous 14-amino acid SRIF peptide (1). When the chimeric genes were placed under the control of yeast acid phosphatase (PHO5) promoter, significant amount of an unglycosylated form of the fusion precursor molecule accumulated intracellularly, suggesting disruption of an endoplasmic reticulum-mediated function. We report here that the appearance of the precursor is due to an alteration in the three amino terminal residues of the chimera, i.e., Met-Arg-Phe in native prepro-alpha-factor is changed to Met-Phe-Lys in the hybrids. The unglycosylated precursor represents a population of molecules that are disrupted at an early stage of targeting to or translocation across the endoplasmic reticulum membrane. Our data demonstrate that the N-terminus plays an important role in topogenesis. Furthermore, these results show that translocation and glycosylation can be uncoupled from protein synthesis in vivo, and therefore can be posttranslational events in yeast.  相似文献   

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PURPOSE: The goal of this randomized study was to determine whether combined general and epidural anaesthesia with postoperative epidural analgesia, compared with general anaesthesia and postoperative intravenous analgesia, reduced the incidence of perioperative myocardial ischaemia in patients undergoing elective aortic surgery. METHOD: Patients were randomly assigned to one of two groups. One group (EPI, n = 48) received combined general and epidural anaesthesia and postoperative epidural analgesia for 48 hrs. The other group (GA, n = 51) received general anaesthesia followed by postoperative intravenous analgesia. Anaesthetic goals were to maintain haemodynamic stability (+/- 20% of preoperative values), and a stroke volume > 1 ml.kg-1. A Holter monitor was attached to each patient the day before surgery. Leads 11, V2, and V5 were monitored. Myocardial ischaemia was defined as ST segment depression > 1 mm measured at 80 millisec beyond the J point or an elevation of 2 mm 60 millisec beyond the J point which lasted > 60 sec. An event that lasted > 60 sec but returned to the baseline for > 60 sec and then recurred, was counted as two separate events. The Holter tapes were reviewed by a cardiologist blind to the patient's group. RESULTS: There were no demographic differences between the two groups. Myocardial ischaemia was common; it occurred in 55% of patients. In hospital, preoperative ischaemia was uncommon (GA = 3, EPI = 8). Intraoperative ischaemia was common (GA = 18, EPI = 25). Mesenteric traction produced the largest number of ischaemic (GA = 11, EPI = 11) events. Postoperative ischaemia was most common on the day of surgery. Termination of epidural analgesia produced a burst of ischaemia (60 events in 9 patients). CONCLUSION: Combined general and epidural anaesthesia and postoperative epidural analgesia do not reduce the incidence of myocardial ischaemia or morbidity compared with general anaesthesia and postoperative intravenous analgesia.  相似文献   

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BACKGROUND: The current AJCC protocol for breast cancer staging does not include additional tumor found at the time of re-excision in the calculation of tumor size. We hypothesize that the AJCC protocol may result in understaging and undertreatment of breast cancer patients who have additional tumor found at re-excision. METHODS: In a retrospective chart review of breast cancer patients, patients with tumor present at re-excision for positive margins were placed in group 1 (n=72); patients with no tumor present at re-excision, or who underwent a single, negative margin procedure were placed in group 2 (n=147). RESULTS: Patients in group 1 had a higher risk of nodal metastases when compared to patients in group 2. Mean tumor size did not differ significantly between the subgroups. Positive re-excision was strongly associated with lymph node metastases on multivariate analysis after correction for age, grade, stage, and lymphatic invasion (odds ratio=3.13, 95% CI=1.58 6.18, P=.0011). CONCLUSIONS: Current AJCC guidelines may result in undertreatment of breast cancer patients with positive re-excisions. The presence of additional tumor at the time of re-excision should be considered when determining the need for systemic therapy, and may be relevant in determining T stage.  相似文献   

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The Pollution Effects on Asthmatic Children in Europe (PEACE) study is a multicentre study of the acute effects of particles with a 50% cut-off aerodynamic diameter of 10 microm (PM10), black smoke (BS), sulphur dioxide (SO2) and nitrogen dioxide (NO2) on the respiratory health of children with chronic respiratory symptoms. The study was conducted in the winter of 1993/1994 by 14 research centres in Europe. A total of 2,010 children, divided over 28 panels in urban and suburban locations, was followed for at least 2 months. Exposure to air pollution was monitored on a daily basis. Health status was monitored by daily peak expiratory flow (PEF) measurements and a symptom diary. The association between respiratory health and air pollution levels was calculated with time series analysis. Combined effect estimates of air pollution on PEF or the daily prevalence of respiratory symptoms and bronchodilator use were calculated from the panel-specific effect estimates. Fixed effect models were used and, in cases of heterogeneity, random effect models. No clear associations between PM10, BS, SO2 or NO2 and morning PEF, evening PEF, prevalence of respiratory symptoms or bronchodilator use could be detected. Only previous day PM10 was negatively associated with evening PEF, but only in locations where BS was high compared to PM10 concentrations. There were no consistent differences in effect estimates between subgroups based on urban versus suburban, geographical location or mean levels of PM10, BS, SO2 and NO2. The lack of association could not be attributed to a lack of statistical power, low levels of exposure or incorrect trend specifications. In conclusion, the PEACE project did not show effects of particles with a 50% cut-off aerodynamic diameter of 10 microm, black smoke, sulphur dioxide or nitrogen dioxide on morning or evening peak expiratory flow or the daily prevalence of respiratory symptoms and bronchodilator use.  相似文献   

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PURPOSE OF THE STUDY: Efficient peri-operative analgesia is more comfortable, allows earlier mobilisation and better functional results for lower limb arthroplasties. We report our 60 cases prospective study of combined spinal and epidural anesthesia, and expose interests of this technique to control peri-operative pain. MATERIALS: From 1994 to 1995, 60 patients ASA class 1 were operated: 45 total hip replacement (THR), 15 total knee replacement (TKR). The average age was sixty five years (range thirty nine to eighty five years). Combined spinal and epidural anesthesia was performed in every case. METHODS: In lateral decubitus position, a translucent 25 Gauge needle was introduced in L2-L3 interspace. In a first time spinal anesthesia was made with 20 mg Bupivacaine. In a second time, a lumbar epidural catheter was inserted. All patients received an epidural post-operative analgesia with 4 mg Morphine once a day during two days and intravenous Paracetamol. Visual analogue scale (0 to 10) (VAS) were recorded after the third post operative hour and every twelve hours. During this period satisfaction mark was also recorded (1 to 3). RESULTS: We didn't observe any case of respiratory depression or infection with the epidural catheter. We observed 10 cases of pruritus (one needed to stop protocol) and 18 urinary retentions. Six uretral catheters were necessary; we had one case of pyelonephritis (escherichia coli). The first micturition was obtained 13.5 hours after the end of surgery. For the fifty nine remaining patients, visual analogue scale was always inferior or equal to 2/10 and the satisfaction mark to 1/3. DISCUSSION: Different techniques allow peri-operative analgesia, but a few are efficient during the first two days. Plexus nerve blocks are simple and reliable but post-operative anesthesia is short (inferior to 15 hours). Intravenous morphine controlled by patients themselves with programmed display needs expensive and sophisticated material. The principal risk is respiratory depression. Epidural morphine has a lower respiratory depression risk, but needs a heavier technique. The principal problems is higher incidence of urinary side effects. Epidural anesthesia might tend to show a greater efficacity with the best visual analogue scale and satisfaction mark. CONCLUSION: The results indicate that combined spinal and epidural anesthesia for the management of peri-operative pain provide an excellent pain control with a daily morphine injection. For lower limb arthroplasties, visual analogue scale is always inferior or equal to 2 and satisfaction mark equal to 1.  相似文献   

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The objective of this pilot study was to evaluate the safety and efficacy of cervical discectomy with fusion performed on an outpatient basis. The experimental group (50 consecutive patients) was studied prospectively and the outcomes were compared with 53 consecutive, retrospectively analyzed, admitted controls who underwent the same procedure. Outcomes for both groups were assessed by patient-response questionnaires and clinical examination. At follow-up times of 1.3 (outpatient) and 1.6 (inpatient) years, outcomes (outpatient/inpatient) expressed as percent successful were as follows: Relief of arm pain (80/70%); relief of neck pain (78/68%); relief of arm muscle weakness and atrophy (94/96%); return to normal activities (64/70%); return to work (65/68%); and satisfaction with the results of surgery (86/83%). No statistically significant differences between outpatients and inpatients were found for any of the outcome parameters studied. There was no mortality and the operative complication rate was 2% for each study group. The results indicate that conversion of cervical discectomy with fusion from an admitted to an ambulatory practice did not compromise the safety or efficacy of the surgical procedure. Potential economic savings to overall health costs of the United States that might result from such conversion could exceed $100 million annually.  相似文献   

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Hydrofluoroalkane-134a (HFA) beclomethasone dipropionate (BDP) was formulated in a metered-dose inhaler (MDI) to deliver a particle size of 1.1 microm compared with 35 microns for currently marketed chlorofluorocarbon (CFC)-BDP products. Two phase I single-dose human deposition studies were conducted using technetium 99m-radiolabelled BDP in a press-and-breathe actuator without an add-on spacer. A healthy volunteer study (n=6) showed that 55-60% of the HFA-BDP ex-actuator dose was deposited in the lungs, with 29-30% deposited in the oropharynx. CFC-BDP deposition was 4-7% in the lungs and 90-94% in the oropharynx. The pattern of deposition within the lung showed that HFA-BDP was spread diffusely throughout the lung airways, whereas CFC-BDP was confined to the central airways with little, if any, peripheral airway deposition. A second study with asthmatics (n=16) confirmed that 56% of the HFA-BDP dose was deposited in the airways, with 33% in the oropharynx. In conclusion, hydrofluoroalkane-134a-beclomethasone dipropionate deposition was much greater in the airways than chlorofluorocarbon-beclomethasone dipropionate, with a concomitant reduction in oropharyngeal deposition. The increased lung deposition efficiency of the hydrofluoroalkane propellant has led to a reduction in the amount of beclomethasone dipropionate needed to achieve a similar efficacy. The penetration of the hydrofluoroalkane to the small airways may provide asthma treatment not afforded by conventional chlorofluorocarbons.  相似文献   

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The use of laparoscopic cholecystectomy in pregnant women has been slow to gain wide acceptance for two reasons: one is the potential for mechanical problems related to the pregnant uterus and the other is fear of fetal injury resulting from instrumentation or the pneumoperitoneum. To assess the effects of laparoscopic cholecystectomy on both the mother and the unborn fetus, we reviewed our surgical experience over a 5-year period analyzing indications for the procedure along with complications and outcome. During this 5-year period, 22 patients ranging in age from 17 to 31 years underwent laparoscopic cholecystectomy during pregnancy. Gestational ages ranged from 5 to 31 weeks with two patients being in the first trimester, 16 in the second, and four in the third. The primary indications for surgical intervention were persistent nausea, vomiting, pain, and inability to eat in 17 patients, acute cholecystitis in three, and choledocholithiasis in two. In all patients a pneumoperitoneum was established by means of a closed technique starting in the right upper quadrant of the abdomen. Two of the 22 patients also underwent successful transcystic common bile duct exploration with removal of common duct stones. All 22 patients survived the surgical procedure without complications, and there were no fetal deaths or premature births related to the procedure. Based on the preceding results, it would appear that laparoscopic cholecystectomy during pregnancy is safe for both the mother and the unborn fetus. Indications for this procedure should include stringent criteria such as unrelenting biliary tract symptoms or the complications of cholelithiasis. If at all possible, when laparoscopic cholecystectomy is indicated, it should be performed either in the second trimester or early in the third.  相似文献   

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In order to assess possible ovarian cell potential for interaction with tamoxifen, thus demonstrating possible effects of this agent on the development of ovarian pathologies through growth stimulation and cell proliferation, we measured estrogen receptors (ER) and progesterone receptors (PR) by immunohistochemical method in 16 benign ovarian tumors removed from 11 postmenopausal breast cancer patients treated with tamoxifen (study group). The results were compared with those measured in 7 similar ovarian tumors obtained from 5 similar patients without tamoxifen treatment (control group I), and in 9 similar tumors removed from 9 age-matched postmenopausal women (control group II). There were no significant differences with regard to ER or PR expression between the study group and control group I and II (ER = 18.75, 0.0 and 11%, respectively; PR = 43.75, 28.5 and 44%, respectively; p = NS). There were also no significant statistical differences between the three groups when subdividing the ovarian pathologies according to different histological types. From the results obtained in this study, it seems that tamoxifen probably does not have any direct influence on the ovaries of menopausal breast cancer patients.  相似文献   

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BACKGROUND: Approximately 15% of women still have pain after placement of an epidural catheter and administration of local anesthetic for labor analgesia. Two techniques frequently used to treat this pain were compared: (1) withdrawal of the catheter 1 cm and repeated dosing with additional local anesthetic, and (2) repeated dosing with additional local anesthetic without any catheter manipulation. METHODS: Fifteen minutes after placement of a multiple-orifice epidural catheter 5 cm into the epidural space and administration of 13 ml 0.25% bupivacaine to the parturient in labor, the adequacy of analgesia was assessed. All women who had incomplete analgesia were randomized (first intervention) to receive an additional 5 ml 0.25% bupivacaine (local-anestheticonly group) or to receive 5 ml 0.25% bupivacaine after first withdrawing the epidural catheter 1 cm (catheter-manipulation group). If after 15 min the woman still had pain, then (second intervention) the catheter was withdrawn 1 cm and an additional 5 ml 0.25% bupivacaine was administered to the local-anesthetic-only group, whereas 5 ml 0.25% bupivacaine was given to the catheter-manipulation group without further catheter manipulation. The success rate of the second intervention was assessed 15 min later. RESULTS: Seventy-eight women were enrolled in the study, 39 to each group. In the local-anesthetic-only group, 29 (74%) women were successfully treated with the first intervention and the remaining 10 (100%) were successfully treated with the second intervention. In the catheter-manipulation group, 30 (77%) were successfully treated with the first intervention and 7 (100%; 2 patients were not studied because of investigator error) were successfully treated with the second intervention (P=NS). CONCLUSIONS: Administration of additional local anesthetic without first withdrawing the epidural catheter will effectively treat most women for whom analgesia is incomplete after the placement of an epidural catheter during labor.  相似文献   

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Three surveys of postoperative patients and surgical ward staff were conducted in an 840-bed university hospital to ascertain the severity of pain after surgery and the reasons why patients in pain do not receive more of the analgesia prescribed for them. In the first survey, 206 inpatients were questioned within 24 h following operation, and 25.2% of patients experienced moderate pain whilst 9.2% experienced severe pain but received only 36% of their prescribed analgesics. In the second survey, 176 staff reported that the commonest reasons why patients in pain did not receive analgesics were that they did not request analgesia, were too sleepy or refused the dose. In the final survey, of 200 inpatients questioned, 88% had experienced pain since operation, 97% had been offered analgesics, 14% refused a dose. Twenty-nine percent were moderately or very concerned about injections. The beliefs of both ward staff and patients could have contributed to this failure of pain relief.  相似文献   

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A series of eye-tracking and categorization experiments investigated the use of speaking-rate information in the segmentation of Dutch ambiguous-word sequences. Juncture phonemes with ambiguous durations (e.g., [s] in 'eens (s)peer,' “once (s)pear,” [t] in 'nooit (t)rap,' “never staircase/quick”) were perceived as longer and hence more often as word-initial when following a fast than a slow context sentence. Listeners used speaking-rate information as soon as it became available. Rate information from a context proximal to the juncture phoneme and from a more distal context was used during on-line word recognition, as reflected in listeners' eye movements. Stronger effects of distal context, however, were observed in the categorization task, which measures the off-line results of the word-recognition process. In categorization, the amount of rate context had the greatest influence on the use of rate information, but in eye tracking, the rate information's proximal location was the most important. These findings constrain accounts of how speaking rate modulates the interpretation of durational cues during word recognition by suggesting that rate estimates are used to evaluate upcoming phonetic information continuously during prelexical speech processing. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   

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BACKGROUND: Basic pharmacological research indicates that there are synergistic antinociceptive effects at the spinal cord level between adrenaline, fentanyl and bupivacaine. Our clinical experience with such a mixture in a thoracic epidural infusion after major surgery confirms this. The objectives of the present study were to evaluate the effects on postoperative pain intensity, pain relief and side effects when removing adrenaline from this triple epidural mixture. METHODS: A prospective, randomised, double-blind, cross-over study was carried out in 24 patients after major thoracic or abdominal surgery. Patients with only mild pain when coughing during a titrated thoracic epidural infusion of about 10 ml.h-1 of bupivacaine 1 mg.ml-1, fentanyl 2 micrograms.ml-1, and adrenaline 2 micrograms.ml-1 were included. On the 1st and 2nd postoperative days each patient was given a double-blind epidural infusion, at the same rate, with or without adrenaline. The effect was observed for 4 h or until pain when coughing became unacceptable in spite of a rescue analgesic procedure. Rescue analgesia consisted of up to two epidural bolus injections per hour and i.v. morphine if necessary. All patients received rectal paracetamol 1 g, every 8 h. Fentanyl serum concentrations were measured with a radioimmunoassay technique at the start and end of each study period. Main outcome measures were extent of sensory blockade and pain intensity at rest and when coughing, evaluated by a visual analogue scale, a verbal categorical rating scale, the Prince Henry Hospital pain score, and an overall quality of pain relief score. RESULTS: The number of hypaesthetic dermatomal segments decreased (P < 0.001) and pain intensity at rest and when coughing increased (P < 0.001) when adrenaline was omitted from the triple epidural mixture. This change started within the first hour after removing adrenaline. After 3 h pain intensity when coughing had increased to unacceptable levels in spite of rescue analgesia (epidural bolus injections and i.v. morphine). Within 15-20 min after restarting the triple epidural mixture with adrenaline, pain intensity was again reduced to mild pain when coughing. Serum concentration of fentanyl doubled from 0.22 to 0.45 ng.ml-1 (P < 0.01), and there was more sedation during the period without adrenaline. CONCLUSIONS: Adrenaline increases sensory block and improves the pain-relieving effect of a mixture of bupivacaine and fentanyl infused epidurally at a thoracic level after major thoracic or abdominal surgery. Serum fentanyl concentrations doubled and sedation increased when adrenaline was removed from the epidural infusion, indicating more rapid vascular absorption and systemic effects of fentanyl.  相似文献   

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