Abnormal error processing in depressive states: a translational examination in humans and rats.

Depression has been associated with poor performance following errors, but the clinical implications, response to treatment and neurobiological mechanisms of this post-error behavioral adjustment abnormality remain unclear. To fill this gap in knowledge, we tested depressed patients in a partial hospital setting before and after treatment (cognitive behavior therapy combined with medication) using a flanker task. To evaluate the translational relevance of this metric in rodents, we performed a secondary analysis on existing data from rats tested in the 5-choice serial reaction time task after treatment with corticotropin-releasing factor (CRF), a stress peptide that produces depressive-like signs in rodent models relevant to depression. In addition, to examine the effect of treatment on post-error behavior in rodents, we examined a second cohort of rodents treated with JDTic, a kappa-opioid receptor antagonist that produces antidepressant-like effects in laboratory animals. In depressed patients, baseline post-error accuracy was lower than post-correct accuracy, and, as expected, post-error accuracy improved with treatment. Moreover, baseline post-error accuracy predicted attentional control and rumination (but not depressive symptoms) after treatment. In rats, CRF significantly degraded post-error accuracy, but not post-correct accuracy, and this effect was attenuated by JDTic. Our findings demonstrate deficits in post-error accuracy in depressed patients, as well as a rodent model relevant to depression. These deficits respond to intervention in both species. Although post-error behavior predicted treatment-related changes in attentional control and rumination, a relationship to depressive symptoms remains to be demonstrated.

Iliosacral screw insertion using computer-assisted CT image guidance: a laboratory study.

Procedures were performed to evaluate the efficacy of using a computer-assisted image-guided system to improve the accuracy of inserting iliosacral screws for posterior pelvic ring injuries. The fluoroscopic method currently in use has shortcomings that do not eliminate the risk to the L5 and sacral nerve roots and iliac vessels. The procedure was performed on embalmed cadaver pelvis specimens with intact soft tissues. Iliosacral screws were inserted across each sacroiliac joint after registering the opposite ilium to simulate a clinical situation. Two trials were performed. The first was necessary to become familiar with the system and test the basic methods of registration. In the second trial, deficiencies were corrected by using spherical-headed fiducial screws for fiducials and a better reference frame clamp, and by better spacing of more fiducials. Results were evaluated by inlet and outlet X-ray views and dissection. All eight S-1 iliosacral 7.0-mm cannulated screws were entirely inside bone. Of the eight S-2 screws, five were inside bone, two infringed upon an S-1 foramen, and one had threads out of the sacral body anteriorly and intruding into an S-1 foramen. This system was felt to be effective and sufficiently safe to warrant clinical trials.

Mortality experience of employees exposed to 2-mercaptobenzothiazole at a chemical plant in Nitro, West Virginia.

Mortality trends for 1059 production workers at a rubber chemicals plant in Nitro, West Virginia were examined to find whether they had increased mortality from cancer associated with exposure to 2-mercaptobenzothiazole (MBT). This chemical and its derivatives are vulcanising agents that have been manufactured at the plant since 1935. Analyses were conducted on MBT exposed employees by cumulative exposure and time since first exposure, and were also stratified by past assignment to p-aminobiphenyl (PAB) related departments; PAB is a potent bladder carcinogen that was used at the plant between 1935 and 1955. There was an excess of bladder cancer in MBT workers who had PAB related assignments (standardised mortality ratio (SMR) = 3200, 95% confidence interval (95% CI) 1286-6593). In employees without a job assignment with exposure to PAB, there were no associations between exposure to MBT and increased rates of most malignant neoplasms. The SMR for bladder cancer was increased based on three deaths (SMR = 455, 95% CI 94-1328), although these results were too few to evaluate trends by cumulative exposure category. The possibility of confounding by PAB for exposures for jobs that covered all areas of the plant for these three cases must be considered in the light of the potency of PAB as a bladder carcinogen. There were no deaths from bladder cancer among MBT workers hired after the end of manufacture and use of PAB, but the expected number of deaths was only 0.03.

Distal locking screw insertion using a cannulated drill bit: technical note.

A modified freehand method using a cannulated drill bit for the insertion of distal locking screws for interlocking intramedullary nails is described. It should be useful to introduce surgeons to interlocking and to aid those who are not comfortable with the freehand method.

Prophylactic intramedullary fixation of the tibia for stress fracture in a professional athlete.

Prophylactic intramedullary nailing of the tibia for stress fracture was performed successfully in a professional football player, enabling him to resume his career. No similar case has been reported previously.

Technical difficulties with the Brooker-Wills nail in acute fractures of the femur.

In this series of 41 cases of acute fractures of the femur treated with the Brooker-Wills nail, 20 technical problems with insertion or removal of the nail occurred in 19 of the total. Final outcomes were determined in 33 cases followed for 1 year or more. Technical difficulties had a deleterious effect on the outcome in three of these 33 cases. Mechanical failure seems to be a significant problem with the Brooker-Wills system in this and other series. We found that bending of the proximal nail during the insertion, breaking of the tip of the distal fixator inserter, and detachment of the blades from the fixator shaft had occurred. Although satisfactory results were obtained in this series, comparable to other "start-up" series, it is our opinion that the advantages of the Brooker-Wills nail over other interlocking nails are outweighed by the disadvantages of difficult insertion and removal.

Deyerle treatment for femoral neck fractures.

Thirty-eight displaced intracapsular fractures of the femoral neck treated by the Deyerle method of internal fixation have been added to the previously reported series of sixty-three cases from the Walter Reed Army Medical Center Orthopaedic Service. A significant change in the incidence of non-union was found. In the over-all series of 101 patients, the incidence of non-union was 13.8 per cent and the incidence of segmental collapse due to avascular necrosis was 13.8 per cent. The roentgenographic and functional over-all end results were rated excellent in 67.7 per cent and poor in 32.3 per cent of the fractures. Some difficulties arising from the multiple-pin and plate technique and the associated morbidity are discussed. We now think that Deyerle method produces no better results than other methods of internal fixation of displaced intracapsular fractures.