Cortical Distribution of Eeg Activity for Component Processes During Mental Rotation

Alpha power (8–12 Hz) was monitored over the frontal, temporal, parietal and occipital lobes of the left and right cerebral hemispheres while participants mentally rotated three-dimensional shapes to match a specified target. By comparing the activational patterns generated during three experimental conditions, each designed to systematically isolate the involvement of the various subcomponents comprising this mental rotation task, it was suggested that the right frontal lobe mediates encoding and comparison/decision processes, while the left parietal and the left temporal region appear most involved in the generation of images and their mental rotation. A preliminary model describing the cooperative interaction of these cortical regions during mental rotation tasks is proposed.     

Red blood cell methotrexate and folate levels in children with acute lymphoblastic leukemia undergoing therapy: a Pediatric Oncology Group pilot study

Summary We enrolled children with acute lymphoblastic leukemia (ALL) in a Pediatric Oncology Group (POG) pilot study to monitor erythrocyte (RBC) methotrexate (MTX) and folate (F) levels before and during treatment. The mean value for RBCF at diagnosis was 0.86±0.46 nmol/ml RBC in the 214 patients who achieved remission and 1.21±0.74 nmol/ml RBC in the 10 patients who did not (P=0.020). Folate levels tended to increase during remission induction, but they dropped following an intensive consolidation with methotrexate to levels that were sustained throughout chemotherapy treatment. Methotrexate levels reached mean values of approximately 0.15 nmol/ml RBC at the end of an intensive methotrexate consolidation, then fell to levels that were sustained throughout maintenance therapy. There was a weak correlation between improved event-free survival and higher RBCMTX levels after consolidation, but no correlation was found between improved survival and the level of RBCMTX or RBCF during maintenance therapy. A larger study with more complete data is needed to determine whether RBCMTX or RBCF might be useful in predicting event-free survival in patients with ALL.This work was supported in part by grants from the National Cancer Institute and the National Institute of Health (CA-30969, CA-28476, CA29139, CA-159-89, and CA-33587)     

Biomechanics of the Ilizarov fixator for fracture fixation.

Compression, distraction, and torsion stiffness of the Ilizarov external fixator was measured in two fracture models in autopsy specimens of tibia and fibula. A transverse model was tested in six frame constructions with the osteotomy site preloaded in four different positions. An oblique model was tested in four frame constructions also with four preloaded positions. Stiffness was more dependent on bone preload than wire number, wire type, or frame design. High stiffness was achieved by bone preloading, by compressing the rings together, by increasing the number of wires, and by using olive wires. The stiffness can be decreased (dynamization) by separating the rings and by removing wires. This data is helpful for frame design of the Ilizarov fixator.     

Antisocial personality disorder, HIV risk behavior and retention in methadone maintenance therapy

In a sample of 55 consecutive methadone maintenance admissions to our clinic, 42% were diagnosed with antisocial personality disorder (ASPD) using the National Institute of Mental Health Diagnostic Interview Schedule NIMH DIS. Individuals with ASPD exhibited greater risk for HIV infection as defined by more sexual contacts, needle use and equipment sharing. Data at 1 year follow-up were obtained on this group of patients. The objective was to compare the ASPD and non-ASPD groups with regards to demographics, drug abuse history, outcome and retention in treatment. There were no significant differences between the groups on any demographic or treatment outcome variables. Survival analysis indicated that there were no group differences in treatment retention. In conclusion, although there were no differences in treatment outcome between ASPD and non-ASPD groups it is possible that ASPD patients who drop out of treatment will be at higher risk for contracting and spreading HIV within the IV drug using population. These data also suggest that in this population the diagnosis of ASPD using primarily behavioral traits as measured in the NIMH-DIS-III, has little utility in predicting treatment outcome.     

Difficult or Impossible Ventilation after Sufentanil-induced Anesthesia Is Caused Primarily by Vocal Cord Closure

Introduction: Opioid-induced rigidity often makes bag-mask ventilation difficult or impossible during induction of anesthesia. Difficult ventilation may result from chest wall rigidity, upper airway closure, or both. This study further defines the contribution of vocal cord closure to this phenomenon.

Methods: With institutional review board approval, 30 patients undergoing elective cardiac surgery participated in the study. Morphine (0.1 mg/kg) and scopolamine (6 micro gram/kg) given intramuscularly provided sedation along with intravenous midazolam as needed. Lidocaine 10% spray provided topical anesthesia of the oropharynx. A fiberoptic bronchoscope positioned in the airway photographed the glottis before induction of anesthesia. A second photograph was obtained after induction with 3 micro gram/kg sufentanil administered during a period of 2 min. A mechanical ventilator provided 10 ml/kg breaths at 10/min via mask and oral airway with jaw thrust. A side-stream spirometer captured objective pulmonary compliance data. Subjective airway compliance was scored. Pancuronium (0.1 mg/kg) provided muscle relaxation. One minute after the muscle relaxant was given, a third photograph was taken and compliance measurements and scores were repeated. Photographs were scored in a random, blinded manner by one investigator. Wilcoxon signed rank tests compared groups, with Bonferroni correction. Differences were considered significant at P <0.05.

Results: Twenty-eight of 30 patients exhibited decreased pulmonary compliance and closed vocal cords after opioid induction. Two patients with neither objective nor subjective changes in pulmonary compliance had open vocal cords after opioid administration. Both subjective and objective compliances increased from severely compromised values after narcotic-induced anesthesia to normal values (P = 0.000002) after patients received a relaxant. Photo scores document open cords before induction, progressing to closed cords after the opioid (P = 0.00002), and opening again after a relaxant was administered (P = 0.00005).     

Developing a VATS lobectomy programme--can VATS lobectomy be taught?

OBJECTIVE: Although VATS lobectomy has been demonstrated to be safe and effective, the technique is not widely practiced. This may, in part, reflect difficulty in acquiring appropriate skills. We have evaluated the effect of experience and training on surgical outcomes during the development and establishment of a VATS lobectomy programme. METHODS: Data were collected prospectively on 276 consecutive VATS lobectomies under the care of a single consultant as either the primary surgeon or supervising four trainees. The series was divided into cohorts of 46 patients. These comprised one trainee cohort and five sequential consultant cohorts. Statistical analysis utilised standard tests of significance. RESULTS: Increasing experience with the VATS lobectomy programme was associated with a significant reduction in operating time but intraoperative blood loss and postoperative stay were not influenced by increasing consultant surgical experience. Training was associated with a mean increase of 22 min operative time (p=0.0005) but no increase in intraoperative blood loss, morbidity, mortality or postoperative stay. The 46 trainee operative times were similar to the first 46 consultant cases. CONCLUSIONS: VATS lobectomy can be safely taught to trainee thoracic surgeons. However, in view of the limited number of centres undertaking VATS lobectomy, training should be coordinated at a national level to concentrate experience and improve uptake of this technique.     

Atypical antipsychotics to treat the neuropsychiatric symptoms of dementia

Neuropsychiatric symptoms are common in older adults with dementia and can be associated with a rapid decline in cognitive and functional status. This article reviews the current literature supporting the use of atypical antipsychotic medications in this population. Among the currently available atypical antipsychotics, risperidone and olanzapine have been the most widely studied in double-blind, randomized, placebo-controlled clinical trials. Despite the common use of other atypical antipsychotic medications, their efficacy and safety in older adults with dementia has not been as extensively studied. Some controversy surrounds the use of atypical antipsychotic agents in older adults with the suggestion that they may increase the incidence of stroke or even death. Despite the potential for increased risk of harm from the use of these medications, atypical antipsychotics are often effective in treating troublesome neuropsychiatric symptoms refractory to other treatments. Whenever possible, these atypical antipsychotic drug treatments should be combined with non-pharmacological treatments to limit the need and dose of antipsychotic drugs and constant monitoring for potential harms should be maintained. The choice of which atypical antipsychotic agent can be guided by the nature and severity of the target symptom and the medication least likely to cause harm to the patient.