Women at risk for AD show increased parietal activation during a fluency task

BACKGROUND

Imaging studies have shown disparities in resting metabolism and in functional activation between cognitively normal individuals at high and low risk for AD. A recent study has shown increased parietal activation in high-risk subjects during a paired associates recall task, which the authors postulated might overlap activation typically observed in verbal fluency.

OBJECTIVE

To determine whether parietal activation is altered in a letter fluency task in cognitively normal individuals at high risk for AD.

METHODS

fMRI was used to compare cortical activation between two groups of cognitively normal women differing in their risk for developing AD. A letter fluency task was used, which activates left frontal and parietal regions. The risk groups differed in family history of AD and APOE allele status but were matched in age, education, and measures of cognitive performance. Average age of the study participants was 53 years.

RESULTS

The regional patterns of brain activation were similar between groups and similar to patterns observed by other investigators. However, the high-risk group showed significantly increased activation in the left parietal region despite identical letter fluency performance between risk groups.

CONCLUSIONS

Cognitively normal individuals at high risk for AD show increased brain activation in the left parietal region with letter fluency, a region adjacent to that observed by others using a recall task. This convergence of results indicates disruption of functional circuits involving the left parietal lobe in asymptomatic individuals at increased risk for AD.

Serial MRI findings in a case of primary lateral sclerosis

A patient with primary lateral sclerosis (PLS) underwent MRI 3 times over 8.5 years. These images demonstrate progressive atrophy of the premotor, parietal, and primary sensorimotor cortex, with sparing of the temporal lobe, occipital lobe, and cerebellum. The pattern of cerebral atrophy was clearly restricted but was more extensive than expected from sensorimotor cortex pyramidal cell loss described in literature autopsy reports of PLS. Cortical motor system degeneration in PLS, whether primary or secondary, may be more extensive than previously believed.

Success factors and hurdles in quality improvement in a children's hospital

A set of nurse/respiratory therapist-driven algorithms developed by a multidisciplinary team with the goal of "liberating" mechanically ventilated pediatric patients more rapidly from the ventilator resulted in sustained improvement over a 47-month period. The difference between expected and observed billed ventilator hour totals was over 22,000 hours (475 hours per month), a 17.5% reduction, which was significant at the P =.03 level by multiple linear regression analysis. Length of stay and mortality rate were unchanged. This difference represents a measure of the unrecognized cost of a nonstandardized approach to the weaning process. This reports reviews this team's success factors and hurdles and offers practical suggestions for pediatric surgeons interested in leading quality improvement initiatives.

Indoloquinoxaline compounds that selectively antagonize P-glycoprotein

Tumor cells often develop drug resistance through overexpression of membrane transport proteins that effectively efflux anticancer agents. The pharmacologies of the two best-studied transporters, P-glycoprotein (Pgp) and MRP1, are partially overlapping but distinct. To improve the therapeutic potential of drug resistance reversing agents, we have developed a program to identify compounds with selectivity for Pgp or MRP1. Screening of a commercial library of compounds identified indoloquinoxaline compounds with transporter selectivity, and certain examples were synthesized and further evaluated. 1,4-Dibutoxy-6H-indolo[2,3-b]quinoxaline and 4,7-dibutoxy-2,3-dihydrobenzimidazole-2-spiro-3-indolin-2-one were synthesized by condensation of 3,6-dibutoxy-1,4-diaminobenzene and isatin. Neither compound was cytotoxic to MCF-7 cells, nor did either one affect the sensitivity of MCF-7/VP or HL-60/ADR cells at doses up to at least 20 microM, indicating that they do not antagonize MRP1. In contrast, each compound, at doses as low as 0.25 microM, sensitized NCI/ADR cells to vinblastine, actinomycin D, Taxol, and doxorubicin, indicating that they effectively reverse Pgp-mediated multidrug resistance (MDR). Furthermore, the compounds sensitized two additional cell lines that overexpress Pgp to this panel of anticancer drugs. However, these compounds did not affect the sensitivities of MCF-7 or T24 cells to these cytotoxic drugs, and did not alter the sensitivities of any of the tested cell lines to cisplatin or 5-fluorouracil. Both compounds enhanced the intracellular accumulation of [3H]vinblastine by NCI/ADR cells, but did not inhibit photoaffinity labeling of Pgp by [3H]azidopine at concentrations up to at least 100 microM. Therefore, these novel nontoxic indoloquinoxalines selectively sensitize Pgp-overexpressing cells to drugs that are subject to transport by this protein, without modulating the sensitivities of MRP1-overexpressing or non-Pgp cells to cytotoxic drugs. Because of this transporter selectivity, we predict that these compounds will be effective MDR modulators in vivo.

An integrated computational pipeline and database to support whole-genome sequence annotation

We describe here our experience in annotating the Drosophila melanogaster genome sequence, in the course of which we developed several new open-source software tools and a database schema to support large-scale genome annotation. We have developed these into an integrated and reusable software system for whole-genome annotation. The key contributions to overall annotation quality are the marshalling of high-quality sequences for alignments and the design of a system with an adaptable and expandable flexible architecture.

Are the favorable outcomes of splenectomy predictable inpatients with idiopathic thrombocytopenic purpura (ITP)?

BACKGROUND

Historically, splenectomy has been an accepted procedure in the management of immune thrombocytopenic purpura (ITP). However, it is also true that the response to splenectomy in patients with ITP seems to be unpredictable. Therefore, the purpose of this study was to identify clinical variables that might predict a favorable response to splenectomy in patients with ITP.

METHODS

Data were collected retrospectively for 40 adult patients with ITP who underwent laparoscopic (LS) and open (OS) splenectomy at Emory University Hospital between 1992 and 1999. Demographics and outcomes were recorded. Age, sex, disease duration, comorbidities (ASA > 2), previous response to steroids and/or other medications, and preoperative platelet count were analyzed by univariate (t-test, Fisher's exact test) and multivariate statistical methods.

RESULTS

Of the 20 patients in each group, improved platelet counts were noted in 18 patients (90%) in the LS group and 20 patients (100%) in the OS group. Follow-up (16 +/- 3 months) was obtained in 19 LS patients (95%) and 16 OS patients (80%), with 84% and 87.5% sustained response rates, respectively. After univariate analysis, two variables (age and disease duration) were found to be significantly related to the outcome of splenectomy (p <lt; 0.01). However, after multiple logistic regression analysis, only disease duration (relative risk = 1.083; CI, 1.004-1.167) was an independent prognostic factor for a sustained response to splenectomy.

CONCLUSION

These results suggest that the response to splenectomy (laparoscopic and open) in patients with ITP cannot be adequately predicted on the basis of presplenectomy clinical variables. However, disease duration and patient age should be taken into consideration when selecting patients for splenectomy.

Response of atypical symptoms of gastro-oesophageal reflux to antireflux surgery

BACKGROUND

Atypical manifestations of gastro-oesophageal reflux (GOR) include asthma, chest pain, cough and hoarseness. The effectiveness of antireflux surgery for these symptoms is uncertain. The present study compared symptomatic response rates for typical and atypical GOR symptoms after fundoplication.

METHODS

Between October 1991 and January 1998, 324 patients underwent laparoscopic fundoplication at Emory University Hospital and returned postoperative questionnaires. Severity of typical (heartburn) and atypical (asthma, chest pain, cough and hoarseness) GOR symptoms was reported by patients on a 0-4 scale before surgery, and at 6 and 52 weeks after operation. Patients were stratified based on preoperative symptoms into three groups: group 1 (severe heartburn/minimal atypical symptoms), group 2 (severe heartburn/severe atypical symptoms) and group 3 (minimal heartburn/severe atypical symptoms).

RESULTS

In group 1 (n = 173) heartburn improved in 99 per cent and resolved in 87 per cent. In group 2 (n = 95) heartburn improved in 95 per cent and resolved in 76 per cent, and atypical symptoms improved in 94 per cent and resolved in 42 per cent. In group 3 (n = 56) atypical symptoms improved in 93 per cent and resolved in 48 per cent. Although all symptoms were improved by fundoplication, resolution was more likely for heartburn than for atypical symptoms.

CONCLUSION

Atypical symptoms of GOR are improved by fundoplication, but symptom resolution occurs in fewer than 50 per cent of patients.

Effects of a weaning protocol on ventilated pediatric intensive care unit (PICU) patients

As part of a learning collaborative sponsored by the Center for the Evaluative Clinical Sciences (CECS) at Dartmouth College, a multidisciplinary pediatric intensive care unit (PICU) group began meeting in 1997 to evaluate potential performance improvement (PI) opportunities. A reduction in mechanical ventilation (MV) hours was the initial team focus. The multidisciplinary team developed and implemented protocols and physician order sets outlining care for MV weaning, neuromuscular blockade/therapeutic paralyzation, and enteral feedings. Since the initiation of our protocols in July 1997, we have significantly reduced the number of hours our PICU patients receive MV.

The effect of low dose methotrexate on bone density

OBJECTIVE

High dose methotrexate (MTX) has been linked with bone loss in oncology patients. However, it is unclear whether longterm low dose MTX used in the treatment of inflammatory arthritis is associated with bone loss. We compared the effect of low dose MTX on bone density in prospectively recruited patients with rheumatoid arthritis (RA) and psoriasis/psoriatic arthritis (Ps/PsA).

METHODS

Thirty RA patients and 30 Ps/PsA patients taking MTX were compared to controls not taking MTX (30 with RA, 27 Ps/PsA). Bone mineral density (BMD) of the radius, lumbar spine, trochanter, and femoral neck was measured using Lunar dual energy x-ray absorptiometry. Student t tests were used to detect differences in bone density (using Z scores) of the MTX group versus controls for both the RA and Ps/PsA groups. Analysis of covariance was used to examine for confounders including disease duration, disease activity, age, and sex.

RESULTS

BMD of the radius/femoral neck/trochanter did not differ significantly between the MTX treated groups and controls when analyzed by Z scores. The mean difference between the MTX group and controls of the femoral neck was 0.040 (95% CI -0.40, 0.12) and 0.060 (95% CI -0.30, 0.15) for the RA and Ps/PsA groups, respectively. The absolute BMD of the lumbar spine (L2-L4) was higher in the RA MTX group than in controls. Analysis of covariance did not reveal an effect of study group on bone density.

CONCLUSION

This study suggests that low dose MTX does not have a negative effect on bone density, at either cortical or trabecular sites.

Cellular pharmacology of cerulenin analogs that inhibit protein palmitoylation

S-palmitoylation is a dynamic post-translational modification of certain proteins, which helps determine membrane association and may function to enhance the interactions of signaling molecules with their activated receptors and effector systems. Unlike enzymes that catalyze other protein lipidation reactions, e.g. farnesylation and N-myristoylation, protein palmitoyltransferase is virtually uncharacterized biochemically. We have described previously the synthesis of cerulenin analogs including cis-2,3-epoxy-4-oxononadecanamide (16C) and cis-2,3-epoxy-4-oxododecanamide (9C) that inhibit protein palmitoylation (Lawrence et al., J Med Chem 1999;42:4932-41), most likely through covalent alkylation of protein palmitoyltransferase. [3H]9C and [3H]16C were prepared by catalytic incorporation of 3H2 into unsaturated precursors for further study of their cellular pharmacology. After 4 hr, T24 bladder carcinoma cells in the absence of serum accumulated a 4-fold higher intracellular level of [3H]16C than of [3H]9C. Uptake of [3H]9C and [3H]16C was reduced by the presence of serum in the medium, suggesting their binding to serum proteins. [3H]9C and [3H]16C alkylated unique patterns of proteins in T24 cells, with proteins of approximately 80 and 31 kDa being labeled by each compound. A panel of human tumor cell lines demonstrated half-maximal proliferation inhibition at concentrations of 7-30, 4-16, and 8-36 microM, for cerulenin, 9C, and 16C, respectively, indicating that the cell lines have approximately equal sensitivity to these compounds. Different cell lines have similar patterns of protein alkylation by [3H]9C or [3H]16C, with labeling intensity related to cytotoxicity of the compounds. Since both 9C and 16C inhibit palmitoylation, the commonly labeled proteins are candidates for human protein palmitoyltransferase.

A computer-based laparoscopic skills assessment device differentiates experienced from novice laparoscopic surgeons

BACKGROUND

The acquisition of laparoscopic skills is difficult to assess. Previously, through the use of a computer-based skills assessment device (SAD), we have shown that assessments of the time needed to perform a task and graded observations of task performance overestimate the speed at which laparoscopic skills can be acquired. The aim of this study was to test the ability of a laparoscopic SAD to differentiate novices from experienced laparoscopic surgeons and thereby further validate its use in surgical education.

METHODS

Using a laparoscopic simulator platform integrated with task simulation and data collection software (MIST VR), we tested both experienced and novice laparoscopists. Each group performed three tasks with a minimum of seven repetitions. The tasks consisted of target acquisition, target traversal, and target manipulation with diathermy. Within each task, time (T), errors (E), and economy of movement for each hand (EML, EMR) were assessed. Results were reported as mean +/- SEM, and comparisons were made using an independent samples t-test.

RESULTS

For the target acquisition task, the expert group performed the task faster than the novice group (5.5 +/- 0.24 vs 7.6 +/- 0.40 sec, p < 0.05); the experts also made fewer errors (0.5 +/- 0.10 vs 0.8 +/- 0.11 errors, p < 0.05), and achieved both a better EML (1.8 +/- 0.6 vs 2.3 +/- 0.9, p < 0.05) and a better EMR (2.0 +/- 0.1 vs 2.9 +/- 0.21, p < 0.05). In the target traversal task, the experts made fewer errors than the novices (2.2 +/- 0.25 vs 4.6 +/- 0.38 errors, p < 0.05). For the manipulation and diathermy tasks, the expert group completed the task faster (30.8 +/- 1.5 vs 39 +/- 1.5 sec, p < 0.05), made fewer errors (5.3 +/- 0.59 vs 8.1 +/- 0.63 errors, p < 0.05), and had a better EML (6.0 +/- 0.37 vs 7.2 +/- 0.45, p < 0.05) and EMR (4.3 +/- 0.23 vs 5.8 +/- 0.36, p < 0.05) than the novices.

CONCLUSION

A laparoscopic skills assessment device can discern levels of laparoscopic manipulative skill. This type of device can be used in surgical training to make objective assessments of the acquisition of laparoscopic skills.

Bile duct injury during laparoscopic cholecystectomy: results of a national survey

OBJECTIVE

To determine whether surgical residency training has influenced the occurrence of common bile duct injuries during laparoscopic cholecystectomy, and to asses the anatomic and technical details of bile duct injuries from the practices of surgeons trained in laparoscopic cholecystectomy after residency versus surgeons trained in laparoscopic cholecystectomy during residency.

SUMMARY BACKGROUND DATA

Shortly after the introduction of laparoscopic cholecystectomy, the rate of injury to the common bile duct increased to 0.5%, and injuries were more commonly reported early in each surgeon's experience. It is not known whether learning laparoscopic cholecystectomy during surgery residency influences this pattern.

METHODS

An anonymous questionnaire was mailed to 3,657 surgeons across the United States who completed an Accreditation Council for Graduate Medical Education (ACGME)-approved residency between 1980 and 1990 (group A) or 1992 and 1998 (group B). All surgeons in group A learned laparoscopic cholecystectomy after residency, and all those in group B learned laparoscopic cholecystectomy during residency. Information obtained included practice description, number of laparoscopic cholecystectomies completed since residency, postgraduate training in laparoscopy, and annual volume of laparoscopic cholecystectomy in the surgeon's hospital. In addition, technical details queried included the completion of a cholangiogram, the interval between injury and identification, the method of repair, and the site of definitive treatment. The primary endpoint was the occurrence of a major bile duct injury during laparoscopic cholecystectomy (bile leaks without a major bile duct injury were not tabulated).

RESULTS

Forty-five percent (n = 1,661) of the questionnaires were completed and returned. Mean practice experience was 13.6 years for group A and 5.4 years for group B. At least one injury occurrence was reported by 422 surgeons (37.6%) in group A and 143 surgeons (26.5%) in group B. Forty percent of the injuries in group A occurred during the first 50 cases compared with 22% in group B. Thirty percent of bile duct injuries in group A and 32.9% of all injuries in group B occurred after a surgeon had performed more than 200 laparoscopic cholecystectomies. Independent of the number of laparoscopic cholecystectomies completed since residency, group A surgeons were 39% more likely to report one or more biliary injuries and 58% more likely to report two or more injuries than their counterparts in group B. Bile duct injuries were more likely to be discovered during surgery if a cholangiogram was completed than if cholangiography was omitted (80.9% vs. 45.1%). Sixty-four percent of all major bile duct injuries required biliary reconstruction, and most injuries were definitively treated at the hospital where the injury occurred. Only 14.7% of injuries were referred to another center for repair.

CONCLUSIONS

Accepting that the survey bias underestimates the true frequency of bile duct injuries, residency training decreases the likelihood of injuring a bile duct, but only by decreasing the frequency of early "learning curve" injuries. If one accepts a liberal definition of the learning curve (200 cases), it appears that at least one third of injuries are not related to inexperience but may reflect fundamental errors in the technique of laparoscopic cholecystectomy as practiced by a broad population of surgeons in the United States. Intraoperative cholangiography is helpful for intraoperative discovery of injuries when they occur. Most injuries are repaired in the hospital where they occur and are not universally referred to tertiary care centers.

An automated technique for measuring hippocampal volumes from MR imaging studies

We describe an automated volumetric measure of the hippocampus obtained with software called the Knowledge-Guided MRI Analysis Program (KGMAP). Postmortem MR images from 56 participants in the Nun Study were used to validate the measure. KGMAP-determined volumes strongly correlated with those obtained with manual tracings and neurofibrillary pathologic findings of Alzheimer disease in the hippocampus. KGMAP provides a rapid and accurate estimate of hippocampal volume that is suitable for use in clinical practice.

Resection and advancement of esophageal mucosa. A potential therapy for Barrett's esophagus

BACKGROUND

Barrett's esophagus affects 5-10% of patients with gastroesophageal reflux disease (GERD) and is associated with a 40-fold increased risk of malignant transformation. Ablative therapies may lead to esophageal perforation or stricture formation if applied too liberally and residual glandular tissue and persistent cancer risk if utilized too sparingly.

METHODS

Ten pigs underwent gastrotomy. Mucosa below the gastroesophageal (GE) junction was elevated by saline injections, circumferentially incised, and secured to an orogastric tube. By traction, the distal esophageal mucosa was inverted 10 cm proximally, then returned to the gastric lumen. In group A (n = 4), the mucosa (5 cm) was resected and the remnant was allowed to retract. In group B (n = 4), the mucosa was simply sutured back into its native position. In group C (n = 2), the mucosa (5 cm) was resected and the proximal segment was advanced and sutured to the gastric mucosa. At 6 weeks, or sooner if stricture developed, the animals were killed. Stricture formation was determined by ex vivo barium esophagram and gross assessment. The extent of fibrosis and epithelial healing were established histologically.

RESULTS

Group A (mucosa resected) developed weight loss and anorexia within 4 weeks. Pathology revealed dense fibrotic stricture without reepithelialization. Group B (mucosa elevated/replaced) gained weight after the operation. Histology demonstrated mucosal healing without significant stricture or fibrosis. Group C (mucosa resected/advanced) also thrived postoperatively. Histology confirmed mucosal healing without evidence of retraction or dense stricture.

CONCLUSIONS

Exposure of submucosal tissues causes esophageal stricture. Mucosal coverage minimizes submucosal fibrosis after injury. Mucosal resection and advancement allows healing without stricture and may have therapeutic potential for patients with Barrett's esophagus.

Outcomes of laparoscopic fundoplication for gastroesophageal reflux disease and paraesophageal hernia

BACKGROUND

Laparoscopic fundoplication has become the standard for operative treatment of gastroesophageal reflux disease (GERD).

METHODS

We reviewed our experience with 1,000 consecutive patients receiving laparoscopic fundoplication for GERD (n = 882) or paraesophageal hernia (n = 118) between October 1991 and July 1999. Patients with achalasia and failed fundoplication were excluded from analysis. All the patients were evaluated preoperatively by upper endoscopy, esophageal manometry, and barium swallow. After 1994, 24-h pH monitoring was performed selectively in patients with extraesophageal symptoms and/or those without erosive esophagitis. There were 490 men 510 women in this review. Their mean age was 49 years. Procedures performed were 360 degrees floppy fundoplication (n = 879), 360 degrees fundoplication without fundus mobilization (Rossetti) (n = 22), 270 degrees posterior fundoplication (n = 96), and anterior fundoplication (n = 2). Esophageal lengthening procedure (Collis gastroplasty) was performed in combination with fundoplication in 15 patients. In seven patients the treatment was converted to open fundoplication.

OUTCOMES

The average length of hospitalization was 2.2 days, and 136 patients stayed longer than 2 days. Major complications occurred in 21 patients: esophageal perforation (n= 10), acute paraesophageal herniation (n = 4), splenic bleeding (n = 2), cardiac arrest (n = 1), pneumonia (n = 3), and testicular abscess (n = 1). Additional operations were required to manage the complications in 14 patients (70%): Four of these procedures were performed emergently, and 10 patients underwent reoperation between 6 h and 10 days. There were three deaths, all of which involved elderly patients with paraesophageal hernia. There were 35 late failures requiring reoperation for recurrence of GERD or development of new symptoms: The treatment of 32 patients was revised laparoscopically, and 4 patients required laparotomy. Beyond 1 year (median follow-up period, 27 months), 94% of the reviewed patients were satisfied with their surgical outcome.

A randomized, controlled trial of methotrexate versus placebo in early diffuse scleroderma

OBJECTIVE

Early diffuse scleroderma (systemic sclerosis; SSc) has no proven treatment. This study was undertaken to examine the efficacy of methotrexate (MTX) in improving the skin and other disease parameters in early diffuse SSc.

METHODS

Seventy-one patients with diffuse SSc of <3 years' duration were enrolled in a multicenter, randomized, placebo-controlled, double-blind trial. Thirty-five patients were treated with MTX and 36 with placebo. Treatment was administered for 12 months. The primary outcome measures were skin score (as determined with 2 different indices) and physician global assessment.

RESULTS

At baseline, there were no statistically significant differences in skin scores, carbon monoxide diffusing capacity (DLco), physician global assessment, or other secondary outcome measurements between the 2 treatment groups. At study completion, results slightly favored the MTX group (mean +/- SEM modified Rodnan skin score 21.4+/-2.8 in the MTX group versus 26.3+/-2.1 in the placebo group [P < 0.17]; UCLA skin score 8.8+/-1.2 in the MTX group versus 11.0+/-0.9 in the placebo group [P < 0.15]; DLco in the MTX group 75.7+/-4.6 versus 61.8+/-3.4 in the placebo group [P < 0.2]). In addition, physician global assessment results favored MTX (P < 0.035), whereas patient global assessment did not differ significantly between groups. When between-group differences for changes in scores from baseline to 12 months were examined using intent-to-treat methodology, MTX appeared to have a favorable effect on skin scores (modified Rodnan score -4.3 in the MTX group versus 1.8 in the placebo group [P < 0.009]; UCLA score -1.2 in the MTX group versus 1.2 in the placebo group [P < 0.02]), but differences in the degree of change in the DLco and physician global assessment were not significant. For the UCLA skin score, these differences in results were not statistically significant after adjustment for baseline differences in sex distribution and steroid use. Dropout rates were similar in the 2 groups.

CONCLUSION

Although results of this trial demonstrated a trend in favor of MTX versus placebo in the treatment of early diffuse SSc, the between-group differences were small and the power to rule out false-negative results was only 50%. Our findings do not provide evidence that MTX is significantly effective in the treatment of early diffuse SSc.

Assessing laparoscopic manipulative skills

BACKGROUND

The rapid emergence of laparoscopic surgery over the past decade has highlighted the need for teaching and assessing laparoscopic manipulative skills. Most analyses consist of a measurement of the time to complete a specified task and a subjective assessment by an observer. Objective assessments of accuracy in the performance of manipulative skills have been lacking. To quantify both speed and accuracy during laparoscopic skill performance, we have developed a skills assessment device (SAD) using a laparoscopic simulator platform and computer-based skills assessment software that precisely measures an instrument's movement during performance of timed laparoscopic manipulations.

STUDY DESIGN

The SAD device measures the time necessary for an operator to complete a task, and the movements of the working end of laparoscopic instruments in three dimensions. Ten nonsurgeons performed 10 repetitions of a standardized laparoscopic manipulation. Data were captured in real time for both hands on a personal computer. Accuracy was determined by calculating the sum of all distances traveled. Duration was measured in seconds. Results are group means.

RESULTS

The time necessary to perform defined laparoscopic manipulative skills improved dramatically during the first 3 repetitions and then stabilized. However, accuracy of manipulations continued to improve over all 10 repetitions.

CONCLUSIONS

When untrained subjects are learning a laparoscopic manipulative task, measurement of time alone fails to account for the more protracted learning curve for accuracy. Therefore, devices and training programs that fail to consider objective assessments of accuracy may overestimate laparoscopic proficiency.

Recursive partitioning analysis of locoregional recurrence patterns following mastectomy: implications for adjuvant irradiation

PURPOSE

Postmastectomy irradiation improves overall survival for breast cancer patients at high risk for locoregional recurrence (LRR). The objective of this study was to use recursive partitioning analysis (RPA) to define patient subgroups at high risk for LRR following mastectomy.

PATIENTS AND METHODS

A cohort of 1031 patients treated on prospective trials with mastectomy and doxorubicin-based chemotherapy without irradiation was analyzed. The variables considered in the RPA were tumor size, number of involved nodes, number of nodes examined, and percentage of nodes involved (nodes involved/nodes examined). The endpoint was LRR +/- distant metastasis. Only patients with complete data were analyzed (n = 913). Median follow-up was 8 years (range, 0.7-22 years).

RESULTS

Involvement of 20% or more of the lymph nodes examined was the most significant variable predicting LRR. Three risk categories were defined. Patients with 20% or more involved nodes and tumors of 3.5 cm or more were at greatest risk for LRR (41% at 8 years). An intermediate-risk group included patients with 20% or more involved nodes and tumors of less than 3.5 cm as well as those with less than 20% involved nodes and tumor size of 5 cm or greater (18% at 8 years). Patients with less than 20% involved nodes and tumor size of less than 5 cm were at lowest risk for LRR (10% at 8 years).

CONCLUSION

Tumor size and extent of nodal involvement play interrelated roles in predicting LRR following mastectomy and systemic therapy. Patients with 20% or greater involved nodes and those with less than 20% nodes and tumors of 5.0 cm or greater are at significant risk of LRR and should be considered for postoperative irradiation.

A hypothalamic stroke producing recurrent hemihyperhidrosis

A 40-year-old man awoke with exuberant sustained sweating of the entire left side of the body, which became intermittent over the next few days. MRI indicated a single linear hyperintensity in the right posterior hypothalamus, diminishing on a repeat scan. He continues to have episodes of left unilateral sweating precipitated by exercise or minor infection.

Urban-rural differences in a memory disorders clinical population

OBJECTIVES

To compare patient characteristics and family perceptions of patient function at one urban and one rural memory disorders clinic.

DESIGN

Secondary, cross-sectional data analyses of an extant clinical database.

SETTING/PARTICIPANTS

First time visits (n = 956) at two memory disorders clinics.

MEASUREMENTS

Patient and family-member demographics and assessment results for the Mini-Mental State Examination (MMSE), instrumental activities of daily living (IADLs), activities of daily living (ADLs), the Memory Change and Personality Change components of the Blessed Dementia Rating Scale, and the Revised Memory and Behavior Problems Checklist.

RESULTS

In both clinics, patients and family members were more likely female. The typical urban clinic patient was significantly more likely to be living in a facility and more educated than the typical rural patient. Urban and rural patients did not show significant differences in age- and education-adjusted MMSE scores or raw ADL/IADL ratings, but the urban family members reported more memory problems, twice as many personality changes, more-frequent behavior problems, and more adverse reactions to problems.

CONCLUSION

Physicians who practice in both urban and rural areas can anticipate differences between patients, and their families, who seek a diagnosis of memory disorders. Our most important finding is that despite similarities in reported functional abilities, urban families appear to be more sensitive to and more distressed by patients' cognitive and behavioral symptoms than rural families. These differences may reflect different underlying needs, and should be explored in further research.

Total Synthesis of Dendroamide A, a Novel Cyclic Peptide That Reverses Multiple Drug Resistance

Dendroamide A (1) was isolated from a blue-green alga on the basis of its ability to reverse drug resistance in tumor cells that overexpress either of the transport proteins, P-glycoprotein or MRP1. Because of this activity, methods for the synthesis of analogues of this oxazole- and thiazole-containing cyclic peptide have been developed, and the total synthesis of 1 has been completed. Highlights of the synthetic strategy are as follows: (1) a dicyclohexylcarbodiimide coupling of D-Ala and L-Thr, followed by reaction with Burgess reagent and DBU-assisted oxidation to form D-Ala-oxazole; (2) formation of D-Val-thiazole and D-Ala-thiazole via modified Hantzsch reactions; and (3) use of molecular modeling to select the preferred precursor for the final cyclization of the peptide analogue. Synthetic 1 demonstrated spectral properties identical to those of the natural product and reversed P-glycoprotein-mediated drug resistance more effectively than MRP1-mediated resistance. Certain of the synthetic precursors had biological activity, indicating that cell permeability and peptide cyclization are necessary for optimal activity. Thus, the structure and the biological activities of the natural product are confirmed, and methods for the synthesis of analogues for further structure-activity explorations are defined.

Differences in functional magnetic resonance imaging activation by category in a visual confrontation naming task

OBJECTIVE

Cortical processing involved in seemingly similar tasks may differ in important ways. The authors mapped cortical regions engaged in a commonly performed picture naming task, seeking differences by semantic category. Functional magnetic resonance imaging was used during presentation of standardized line drawings in 18 healthy right-handed female participants, comparing living versus nonliving entities. During visual naming, across categories there was strong activation of left frontal (BA45/47), bilateral temporo-occipital junction (BA19), and inferior temporal regions (BA36/37). Activation of right inferior temporal cortex (BA19 and BA37) was greater during naming of living versus nonliving category items. No category differences in activation strength in the left temporal lobe were observed. The authors conclude that visual semantic operations may involve visual association cortex in the right temporal lobe in women.

Genital infection and termination of pregnancy: Are patients still at risk?

OBJECTIVES

To identify the treatment patterns and early complication rates in women identified with a genital infection prior to a termination of pregnancy (TOP) and to re-assess our earlier work on contact attendance and treatment. The aim was to refine current prophylactic measures to provide the most efficient and effective way of reducing post-termination complications.

METHOD

Six-month retrospective analysis of all women with genital Chlamydia trachomatis or Neisseria gonorrhoeae identified prior to TOP. Data on the timing of positive results and treatment in relation to the TOP were recorded. Clinical signs of pelvic infection and the success of contact tracing and treatment were noted.

RESULTS

Forty women were identified with infection, 31 (78%) proceeded to TOP; only five were treated adequately in the peri-TOP period. Twenty-six (84%) of the women undergoing TOP attended the genitourinary medicine (GUM) department after the TOP and received antimicrobial therapy where necessary. In total, four women (10%) were untreated. Approximately two thirds of results were reported prior to, or on the day of, the TOP. The majority of TOPs (71%) were carried out at 5 days or less from the initial assessment. Clinical signs of post-TOP pelvic inflammation developed in seven (28%) women with chlamydial infection. Contact tracing was successful in 24 (69%) of the 35 women who attended the GUM department.

CONCLUSION

The debate about the best option for the most effective management of women undergoing TOP continues. The options with respect to C. trachomatis include universal prophylaxis, screening and treating as necessary, or a 'belt and braces' approach of screening all and treating all. Fundamental is the continuation of active contact tracing and GUM remains integral to this.