Perceptual asymmetry during free viewing of words and faces: The effect of context on recognition

There is ample evidence supporting the dissociation between the role of the left and right cerebral hemispheres in processing words and faces, respectively. Nevertheless, research has not yet studied the effect of perceptual asymmetry in memory context effect tasks using words and faces. Thus, the present study researches the advantages of presenting information in the right versus left hemispace and the effect of context on recognition when using faces compared to words presented in the right versus left hemispace. Participants (n=60) were assigned either to the group presented with pairs of words, or with pairs of faces. One stimulus in each pair was designated as the target (i.e., to be remembered) and the other served as context (i.e., to be ignored). Half of the targets were presented in the right hemispace, and half were presented in the left hemispace. As predicted, words were better recognized when presented in the right hemispace, while faces were better remembered when presented in the left hemispace. The most interesting finding is the influence of context on lateralized processing of words and pictures. That is, only when words or faces were presented in the left hemispace did contextual information affect target memory (though it yielded a different pattern of effect). Hence, the findings of the present study may be interpreted either as reflecting attentional bias to the left hemispace or structural differences between the hemispheres. Thus, cognitive processes and the content of the stimuli determine which hemisphere will be involved in processing contextual information.

A prospective evaluation of the value of anorectal physiology in the management of fecal incontinence

PURPOSE

This study was designed to determine whether anorectal physiology testing significantly altered patient management in the setting of fecal incontinence.

METHODS

Patients referred to the anorectal physiology laboratory for evaluation of fecal incontinence were prospectively interviewed and examined by a colon and rectal surgeon. A decision to treat either medically or surgically was reached. The patients underwent physiologic testing with transanal ultrasound, pudendal nerve terminal motor latency, and anorectal manometry. A panel of board-certified colon and rectal surgeons then reviewed the history and physical examination, as well as the anorectal physiology tests, of each patient and reached a consensus on management. Management plans before and after physiologic evaluation were compared.

RESULTS

Ninety patients (6 males) were entered into the study. The patients were divided in two groups: those with pretest medical management plans (n = 45) and those with pretest surgical management plans (n = 45). A change in management was noted in nine patients (10 percent). In the medical management group, the management changed from medical to surgical therapy in five patients. Transanal ultrasound detected anal sphincter defects in all patients who changed from medical to surgical management but in only 10 percent of those who remained under medical management (P = 0.0001). In the surgical management group, three patients (7 percent) changed from surgical to medical therapy and one patient (2 percent) changed from sphincteroplasty to neosphincter. Transanal ultrasound detected a limited anal sphincter defect in one patient (33 percent) who changed from surgical to medical management and a significant defect in all 41 patients (100 percent) who remained under surgical management (P = 0.003).

CONCLUSIONS

Anorectal physiology testing is useful in the evaluation of patients with fecal incontinence. Without the information obtained from physiologic testing, 11 percent of patients who may have benefited from surgery would not have been given this option, and 7 percent of patients could have potentially undergone unnecessary surgery. Transanal ultrasound is the study most likely to change a patient's management plan.

Clinical use of the self-expanding metallic stent in the management of colorectal cancer

PURPOSE

This report describes our experience with the use of self-expanding metallic stents (SEMS) in the management of obstructing colorectal cancer.

METHODS

A retrospective chart review of all patients undergoing placement of SEMS between May 1997 and January 2000 was performed.

RESULTS

Insertion of SEMS was attempted in 12 patients. Successful stent placement was achieved in 10 of the 12 patients. The locations of lesions were hepatic flexure (2), splenic flexure (1), left colon (1), sigmoid colon (4) and rectum (4). The intended uses of SEMS were for palliation in 3 patients and as a bridge to elective surgery in 9. In the latter group, SEMS placement allowed for preoperative bowel preparation in 4 patients and administration of neoadjuvant therapy prior to elective surgery in 2 patients. One patient died prior to definitive surgery. Stent placement was unsuccessful in 2 patients. Three SEMS-related complications occurred; 1 stent migrated and 1 stent obstructed secondary to tumor ingrowth. One patient died 13 days after stent placement and colonic decompression.

CONCLUSION

SEMS represent a useful tool in the management of obstructing colorectal neoplasms. As a bridge to surgery, SEMS provide time for a complete preoperative evaluation and a mechanical bowel preparation and may obviate the need for fecal diversion or on-table lavage. It may also allow for time to administer neoadjuvant therapy when indicated. As a palliative measure, SEMS can eliminate the need for an operation.

How I do it. Anal stenosis

BACKGROUND

Anal stenosis represents a technical challenge in terms of surgical management. It is a rare but serious complication of anorectal surgery, most commonly seen after surgical hemorrhoidectomy. However, stenosis can also occur in the absence of an anorectal surgical history.

DATA SOURCES

A review of the current surgical literature was performed. The etiology, classification, and diagnostic modalities for anal stenosis were reviewed. A detailed overview of surgical and nonsurgical therapeutic options was developed.

CONCLUSIONS

Anal stenosis may be anatomic (stricture) or functional (muscular). Anal stricture is most often a preventable complication. It is most commonly seen after overzealous surgical hemorrhoidectomy. A well-performed hemorrhoidectomy is the best way to avoid anal stricture. Symptomatic mild functional stenosis and stricture may be managed conservatively with diet, fiber supplements, and stool softeners. A program of gradual manual or mechanical dilatation may be required. Sphincterotomy and various techniques of anoplasty have been used successfully in the treatment of symptomatic moderate to severe functional anal stenosis and stricture, respectively.

Evaluation and outcome of the delorme procedure in the treatment of rectal outlet obstruction

PURPOSE

This study was designed to assess the results of the Delorme procedure in the treatment of patients with rectal outlet obstruction.

METHODS

A descriptive retrospective study from October 1989 to October 1997 was undertaken. Thirty-four patients with an abnormal defecography documenting rectal outlet obstruction caused by internal rectal prolapse or a combination of internal rectal prolapse and rectocele were included in the study.

RESULTS

Thirty-four patients (33 females) ages 35 to 82 (mean, 61.4) years were followed up for the duration of the study (mean follow-up, 43 months). Twenty-six patients (76.4 percent) reported a good to excellent overall result after the Delorme procedure. Eight patients (23.6 percent) reported fair to poor results. Symptomatic improvement was observed in 89.7 percent for patients who had incomplete evacuation, and in 88.5 percent of patients who had constipation. There was improvement in 78.6 percent of patients with bleeding per rectum, in 92.9 percent of patients with straining, and in 82.4 percent of patients with the need to manually assist in defecation by pushing in the perineum or vagina. Discontinuation of laxative use after the procedure was reported by 66.7 percent of patients. Improvement in the patients with some degree of incontinence was seen in 33.3 percent. Twelve patients (35.3 percent) experienced one or more complications. The procedure was performed in an outpatient setting in 71 percent of the patients.

CONCLUSIONS

The Delorme procedure for the treatment of rectal outlet obstruction can be done with minimal morbidity, short hospital stay often in an outpatient setting, with good functional results, and with an overall patient satisfaction above 75 percent.

Morphometric estimation of superoxide generation in allergen-induced airway hyperresponsiveness

BACKGROUND

We previously reported that the airway hyperresponsiveness (AHR) that follows antigen challenge is mediated, in part, by the generation of reactive oxygen species. The purpose of this study was to provide quantitative morphologic evidence of oxygen radical production in the airways during antigen-induced AHR.

EXPERIMENTAL DESIGN

Allergic sheep with a history of early and late bronchial responses to inhaled Ascaris suum antigen were used. The sheep were either challenged with antigen (N = 5) or saline (N = 5) and then euthanized 24 hours later when AHR had been documented to occur. Complete transverse sections of the right cranial lobar bronchus were obtained from the animals and were washed three times in Tris buffer and then incubated for 20 minutes in an oxygenated solution of diaminobenzidine which, in the presence of superoxide and manganese, forms an insoluble amber reaction product. Superoxide dismutase (SOD, 2250 units/ml) and phorbol ester (phorbol myristate acetate, 0.5 microgram/ml) were added to some tissues and used as negative and positive controls, respectively. The bronchial samples were then fixed and embedded in paraffin for light microscopy. The diaminobenzidine reaction product was quantified by determining the volume fraction of reaction product by point counting with a differential interference contrast microscope without counterstain.

RESULTS

Diaminobenzidine reaction product increased 5-fold (p < 0.05) in challenged animals, and this response was blocked by SOD. The reaction product was localized in and around the airway epithelium. Antigen challenge also resulted in a 2.4- and 2.0-fold increase in eosinophils and metachromatic cells in the airway wall. There were no differences in the number of neutrophils between groups. Pretreatment of animals (N = 2) with the combination of the 5-lipoxygenase inhibitor (zileuton, 10 mg/kg, po) and the platelet-activating factor antagonist (WEB-2086, 3 mg/kg, i.v.) agents, which have been shown to block AHR and antigen-induced inflammation in the sheep model, also blocked the antigen-induced superoxide formation.

CONCLUSIONS

These data suggest that superoxide and increased numbers of mediator-containing inflammatory cells are present in sheep airways 24 hours after antigen challenge. The interaction of this reactive oxygen species with these cells could contribute to the AHR seen at this time.

Evaluation of ketanserin in the prevention of restenosis after percutaneous transluminal coronary angioplasty. A multicenter randomized double-blind placebo-controlled trial

BACKGROUND

Ketanserin is a serotonin S2-receptor antagonist that inhibits the platelet activation and vasoconstriction induced by serotonin and also inhibits the mitogenic effect of serotonin on vascular smooth muscle cells.

METHODS AND RESULTS

We conducted a randomized, double blind, placebo-controlled trial to assess the effect of ketanserin in restenosis prevention after percutaneous transluminal coronary angioplasty (PTCA). Patients received either ketanserin (loading dose, 40 mg 1 hour before PTCA; maintenance dose, 40 mg bid for 6 months) or matched placebo. In addition, all patients received aspirin for 6 months. Coronary angiograms before PTCA, after PTCA, and at 6 months were quantitatively analyzed. Six hundred fifty-eight patients were entered into the intention-to-treat analysis. The primary clinical end point of the study was the occurrence between PTCA and 6 months of any one of the following: cardiac death, myocardial infarction, the need for repeat angioplasty, or bypass surgery. It also included the need for revascularization actuated by findings at 6-month follow-up angiography. The primary clinical end point was reached by 92 (28%) patients in the ketanserin group and 104 (32%) in the placebo group (RR, 0.89; 95% CI, 0.70, 1.13; P = .38). Quantitative angiography after PTCA and at follow-up was available in 592 patients (ketanserin, 287; control, 305). The mean difference in minimal lumen diameter between post-PTCA and follow-up angiogram (primary angiographic end point) was 0.27 +/- 0.49 mm in the ketanserin group and 0.24 +/- 0.52 mm in the control group (difference, 0.03 mm; 95% CI, -0.05, 0.11; P = .50).

CONCLUSIONS

Ketanserin at the dose administered in this trial failed to reduce the loss in minimal lumen diameter during follow-up after PTCA and did not significantly improve the clinical outcome.

Initial management and long-term clinical outcome of restenosis after initially successful percutaneous transluminal coronary angioplasty

Restenosis remains a critical limitation after percutaneous transluminal coronary angioplasty (PTCA). The clinical experience with restenosis was reviewed in 1,490 patients who had restenosis of at least 1 site within 1 year of their PTCA. The source of data was the clinical database at Emory University. Patients who had previous coronary bypass surgery or PTCA and patients who underwent PTCA in the setting of acute myocardial infarction were excluded. When restenosis was angiographically documented, 363 were treated medically, 1,051 with repeat PTCA, and 76 with coronary bypass surgery. In the repeat PTCA group there were 778 patients who originally had 1-vessel disease and 273 with multiple vessel disease. Re-dilatation of restenotic sites was performed in 95%. Angiographic success of all lesions dilated was achieved in 99%. Coronary bypass surgery was required in 2.5% of patients with restenosis first treated with repeat PTCA. One patient with multiple vessel disease died. Coronary bypass surgery was performed in fewer patients aged greater than or equal to 65 years, but more patients with multiple vessel disease. Two (2.6%) of the coronary bypass surgery patients had Q-wave myocardial infarction and there were no deaths. In the PTCA group, 5-year actuarial survival was 95%, and cardiac survival 96%. Freedom from cardiac events or further revascularization procedures was 51% at 5 years. Patients treated with PTCA and medically treated patients had similar cardiac survival rates. The most important correlates of cardiac survival were age and the presence of diabetes mellitus. At 5 years, cardiac survival without diabetes was 97 and 83% with diabetes (p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical implications of late proven patency after successful coronary angioplasty

BACKGROUND

The introduction of percutaneous transluminal coronary angioplasty (PTCA) has changed the pattern of intervention in coronary artery disease. However, the long-term results in patients undergoing successful, elective, native-vessel PTCA are not yet fully characterized. Because the healing and subsequent proliferative response after angioplasty are time related, it was the purpose of the present study to determine the long-term outcome in patients whose dilated arteries have been demonstrated to be patent 4-12 months after successful, uncomplicated PTCA.

METHODS AND RESULTS

The patients were grouped on the basis of the 4-12 month catheterization into those whose vessels were angiographically "normal" or had luminal irregularities only at the PTCA sites (396 patients), those whose vessels also had luminal irregularities elsewhere with or without PTCA site luminal irregularities (680 patients), and those with significant obstructive disease (more than 50% diameter narrowing) at sites other than the PTCA sites (426 patients). Of 1,502 such patients, long-term follow-up was available in 1,491. At the time of the original angioplasty, the normal patients had a 1.8% incidence of multivessel disease; luminal irregularity patients, 9.4%; and obstructive disease patients, 58.7%. At angiographic restudy, 16.4% of the obstructive disease patients continued to have multivessel disease. The patients were followed for the events of death, myocardial infarction, coronary surgery, and repeat PTCA. The 6-year survival rate was 95%; cardiac survival, 96%; and freedom from all events, 65%. The strongest correlate of events during follow-up was the angiographic status of the undilated segments. At 6 years, freedom from cardiac events was noted in 77% of the normal group, 61% of the luminal irregularity group, and 55% of the obstructive disease group. Diabetes and hypertension were also independent correlates of events.

CONCLUSIONS

Results from the present study show that associated disease in undilated segments is a strong predictor of late events in patients after successful, uncomplicated, reatenosis-free PTCA. However, the need for further revascularization was frequent even in patients without obstructive disease. Completeness of revascularization is appropriate when possible, and limiting progression of coronary disease at sites remote from those dilated should improve on these late results.

Changing use of coronary angioplasty and coronary bypass surgery in the treatment of chronic coronary artery disease

Changes in the use of coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) over the last several years have resulted in a new and different environment for the interventional treatment of coronary artery disease. This study explores these changes as applied to the treatment of chronic coronary artery disease. The study population comprised 14,078 patients undergoing diagnostic cardiac catheterization between 1981 and 1988. In 1981, 1,704 patients underwent a first known cardiac catheterization at Emory University Hospital or Crawford W. Long Hospital and were found to have significant coronary artery disease. Of these patients, 51.7% were treated medically, 44.0% by CABG and 4.3% with PTCA. A similar group comprised 1,719 patients in 1988. Of this group 41.2% were treated medically, 28.5% with CABG and 30.3% with PTCA. The data reveal a much more complex phenomenon than a simple increase in PTCA for the treatment of coronary disease at the expense of CABG. The CABG group aged such that the percent of the CABG population more than 65 years old increased from 26.0% of the total in 1981 to 44.9% of the total in 1988. The percent of patients with ejection fractions less than 50% in the CABG population increased from 24.5% in 1981 to 29.7% in 1988. The PTCA population had less severe disease, was younger and had better left ventricular function.(ABSTRACT TRUNCATED AT 250 WORDS)

A double blind comparison of alfentanil and fentanyl

Alfentanil and fentanyl were compared as supplements to thiopentone, nitrous oxide, relaxant anaesthesia in a randomised, double blind trial carried out on 55 adult patients undergoing elective surgery. The fentanyl-treated patients resumed spontaneous ventilation more rapidly at the end of anaesthesia (3 minutes) than the alfentanil-treated group (5.1 minutes, p less than 0.02). In other respects the drugs appeared indistinguishable. A computer model is used to explain why, despite the shorter elimination half-life, the alfentanil-treated patients did not awaken more rapidly than those in the fentanyl group.

Postoperative analgesia for haemorrhoid surgery

Seventy patients undergoing haemorrhoidectomy under general anaesthesia were randomly allocated to one of five treatment groups in order to compare the effectiveness of various caudal agents in the control of postoperative pain. Four groups were given a caudal injection of either 2% lignocaine, 0.5% bupivacaine, 2% lignocaine + morphine sulphate 4 mg or normal saline + morphine sulphate 4 mg, while the fifth (control) group did not receive an injection. The number of patients requiring postoperative opiates was significantly higher in the lignocaine group than in the morphine (p less than 0.05) and morphine-lignocaine (p less than 0.05) groups. No agent significantly reduced the number requiring opiates. In those who received opiates, the mean analgesic period was 228 minutes in the control group, and was significantly longer following bupivacaine (577 min, p less than 0.01), morphine-lignocaine (637 min, p less than 0.05) and morphine (665 min, p less than 0.0). The mean analgesic period following lignocaine (349 min) was not significantly different from control. The incidence of catheterisation was lowest in those patients who did not receive caudal analgesia.

Experimental comparison of extradural and i.m. morphine

Morphine sulphate 3 or 4 mg was administered to the extradural space in five volunteers. Morphine 10 or 15 mg i.m. was given as control. Extradural administration resulted in an increase of pain threshold in the legs but not in the forehead. There was no significant depression of carbon dioxide response or deterioration of co-ordination or short-term memory. I.m. morphine caused an increase in forehead pain threshold, depression of the carbon dioxide response and some deterioration of cerebral function. Extradural morphine caused urinary retention in four and inability to ejaculate in three of the subjects. The principal site of action of extradural morphine appears to be regional, at spinal cord level, but it appears that autonomic function as well as pain perception can be affected.

A new intubating forceps

A new intubating forceps is described. The forceps grip the endotracheal tube from the front and back instead of from the side as do Magill's forceps. The advantages of the forceps are a more secure grasp; improved field of vision; better manipulating ability and reduced likelihood of trauma to tissues or tube cuff.