Functional differences among those high and low on a trait measure of psychopathy.

BACKGROUND: It has been established that individuals who score high on measures of psychopathy demonstrate difficulty when performing tasks requiring the interpretation of other's emotional states. The aim of this study was to elucidate the relation of emotion and cognition to individual differences on a standard psychopathy personality inventory (PPI) among a nonpsychiatric population. METHODS: Twenty participants completed the PPI. Following survey completion, a mean split of their scores on the emotional-interpersonal factor was performed, and participants were placed into a high or low group. Functional magnetic resonance imaging data were collected while participants performed a recognition task that required attention be given to either the affect or identity of target stimuli. RESULTS: No significant behavioral differences were found. In response to the affect recognition task, significant differences between high- and low-scoring subjects were observed in several subregions of the frontal cortex, as well as the amygdala. No significant differences were found between the groups in response to the identity recognition condition. CONCLUSIONS: Results indicate that participants scoring high on the PPI, although not behaviorally distinct, demonstrate a significantly different pattern of neural activity (as measured by blood oxygen level-dependent contrast)in response to tasks that require affective processing. The results suggest a unique neural signature associated with personality differences in a nonpsychiatric population.     

The frequency of vitamin D deficiency in adults with Crohn's disease.

BACKGROUND: Vitamin D deficiency is a putative, pathogenic cofactor in the increase in osteopenia and osteoporosis seen in patients with Crohn's disease. OBJECTIVE: To determine the frequency of low serum 25-hydroxy-vitamin D3 (25-OHD) levels and the associated alterations in bone mineral density in a cohort of adults with Crohn's disease. METHODS: 25-OHD levels were determined in 242 consecutive patients with Crohn's disease seen in two tertiary inflammatory bowel disease referral centres. Bone mineral density was assessed by dual energy x-ray absorptiometry. RESULTS: Nineteen (8%) patients exhibited vitamin D deficiency (25-OHD less than 25 nmol/L) and 52 (22%) patients exhibited vitamin D insufficiency (25-OHD less than 40 nmol/L). Mean T-scores at the lumbar spine, femoral neck, total hip and ultradistal radius in the group with low 25-OHD did not differ from those of the normal 25-OHD group. Serum alkaline phosphatase and parathyroid hormone levels were higher in the low 25-OHD group than in the normal group. Decreased red blood cell (RBC) folate predicted low 25-OHD in male patients, while smoking, RBC folate and serum iron predicted low 25-OHD in female patients. The rate of low 25-OHD deficiency in the winter was significantly higher than that in the summer (11.9% versus 2.8%, respectively). CONCLUSION: Vitamin D-deficient Crohn's disease patients exhibit biochemical evidence of metabolic bone disease, without detectable differences in bone mineral density. Sunlight exposure, nutrition and smoking status were predictors of vitamin D deficiency in this patient cohort.     

Through a glass darkly: the disutility of the DSM nosology of depressive disorders.

OBJECTIVE: To demonstrate that the dimension-weighted DSM-IV model for classifying the depressive disorders lacks utility. METHOD: The logical flaws in classifying the depressive disorders with any severity-based model (which underpin both the DSM-IV and ICD-10 systems) are noted. Integral definitional limitations to the DSM-IV definition of key depressive disorders are identified. It is argued that the DSM-IV classificatory system lacks utility for providing information on etiology and preferential management strategies. An alternative subtyping model is considered. RESULTS: It is asserted that, in practice, the DSM-IV model and criteria lack explanatory power and compromise research and clinical practice. CONCLUSIONS: It is hoped that this article evokes wider debate about modelling and classifying the depressive disorders.     

Wrist ratio correlation with carpal tunnel syndrome in industry

Employees from a large midwestern automobile manufacturing plant completed a preemployment evaluation which included a personal and family history, physical examination, and wrist ratio determinations obtained by dividing the anteroposterior diameter by the mediolateral diameter of the wrist. Over a 3-year period, 80 of these employees who developed symptoms compatible with carpal tunnel syndrome within 4-12 months of employment were entered into the study and were evaluated with standard electrodiagnostic techniques. The symptoms included nocturnal hand pain, paresthesia and weak grasp. Thirty-nine of the 80 employees had wrist ratios equal to or greater than 0.70. Twenty-four percent of the employees with wrist ratios less than 0.70 had abnormal electrodiagnostic studies compared with 74% of employees with wrist ratios greater than or equal to 0.70. Regression analysis performed on the data revealed a significant positive correlation between distal median motor latency and wrist ratio (P = 0.001). The study suggests the practical value of wrist ratio determination in job placement.     

Eales' disease presenting as stroke in the young adult

Eales' disease is an uncommon idiopathic disorder characterized by retinal perivasculitis and recurrent vitreous hemorrhages in young males. Associated neurological involvement is rare. We report a 38-year-old man who presented with stroke attributed to Eales' disease.     

ADP plays a key role in thrombogenesis in rats

The relative importance of ADP, arachidonic acid metabolites and serotonin as thrombogenic factors was evaluated in rats by comparing, after oral administration, the effects of two inhibitors of ADP-induced platelet aggregation (ticlopidine and PCR 4099), three cyclo-oxygenase inhibitors (aspirin, triflusal and indobufen) and a selective serotonin 5HT2 receptor antagonist (ketanserin) on platelet aggregation, in four platelet-dependent thrombosis models and on bleeding time. Platelet aggregation induced by ADP and collagen was completely inhibited by ticlopidine and PCR 4099 whereas only the collagen aggregation was reduced by the cyclo-oxygenase inhibitors. Ketanserin or a depletion of platelet serotonin by reserpine did not affect platelet aggregation. Ticlopidine and PCR 4099 greatly prolonged rat tail transection bleeding time. This is probably related to their known ability to inhibit ADP-mediated platelet aggregation. In contrast, the cyclooxygenase inhibitors did not affect bleeding time at all. Reserpine and ketanserin prolonged bleeding time by interfering with the action of serotonin on the vascular wall. Ticlopidine and PCR 4099 were very potent antithrombotics in all the models. Aspirin, only at a high dose, inhibited poorly thrombus formation on a silk thread in an arterio-venous shunt, suggesting that the inhibition of cyclo-oxygenase was not responsible. Triflusal was inactive in all models while indobufen slightly reduced thrombus formation in the silk thread and metallic coil models. Ketanserin and reserpine reduced thrombus only in the metallic coil model. Thrombus formation was greatly reduced in fawn-hooded rats, which lack ADP in their platelet dense granules because of a genetic storage pool deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)     

Improved preservation of skeletal muscle in amputated limbs using pulsatile hypothermic perfusion with University of Wisconsin solution. A preliminary study.

To determine whether pulsatile hypothermic perfusion with University of Wisconsin preservation solution is superior to topical cooling as a method for the preservation of amputated limbs, six pairs of amputated canine limbs were preserved for twelve to fifteen hours. One limb of each pair was subjected to topical cooling and the other, to pulsatile hypothermic perfusion with University of Wisconsin solution. The bioenergetic status of the limbs was monitored by 31phosphorus magnetic-resonance spectroscopy, and histological evaluation was performed to assess ischemic changes in the preserved tissue. The pH and tissue levels of adenosine triphosphate declined three times more slowly in the limbs that were preserved by pulsatile hypothermic perfusion than in the topically cooled limbs. Consistent with these findings, the perfused limbs also had less histological evidence of ischemic injury. The data from this in vitro study show that pulsatile hypothermic perfusion with University of Wisconsin solution, in combination with an optimum degree of topical cooling, is superior to topical cooling alone as a method of preserving the bioenergetic status of amputated limbs.     

Skill learning and repetition priming in Alzheimer's disease.

While perceptual-motor learning occurs normally in Alzheimer's disease (AD) patients, their ability to acquire the skill of reading transformed text has not been well delineated. AD patients and matched controls were timed as they read two blocks of words presented in mirror image. Control subjects displayed both skill learning and repetition priming, whereas AD patients displayed only repetition priming. Skill learning in AD patients was associated with their ability to complete verbal analogies. They displayed the expected impairment in recognition for the words from the mirror reading task. The failure of AD patients to acquire the mirror reading skill can be understood through a task analysis and may reflect an underlying deficit in abstract reasoning that precludes the development of appropriate pattern analyzing strategies needed to transform rotated text.     

Activation of muscle fibers in individual motor units revealed by 2-deoxyglucose-6-phosphate

Motor units of the cat tibialis posterior muscle were selectively activated by prolonged electrical stimulation of functionally isolated motor axons in situ. During the activation, the glucose analog 2-deoxyglucose (DG) was administered systemically. Single muscle fibers were subsequently examined for accumulation of the metabolite 2-deoxyglucose-6-phosphate (DG6P) by an analytical assay and for depletion of glycogen by a PAS glycogen-specific staining reaction (periodic acid Schiff; PAS). In general, levels of DG6P were 20 times greater in unstained (PAS-negative) fibers compared with stained (PAS-positive) fibers. However, some glycogen-depleted fibers, particularly in putative ischemic fascicles of the muscle, did not have elevated DG6P, suggesting that depletion of glycogen is not always a reliable indicator of fiber activation. Furthermore, the PAS-staining reaction was not necessarily indicative of quantitative glycogen levels in single fibers. Thus, this report shows that DG6P accumulation enhances the identification of motor-unit fibers selectively activated via their common motor-nerve axon. Evidence is also presented for differential glucose uptake in muscle fibers of different phenotype, thereby indicating that the DG6P measurement in muscle has broad applicability to the investigation of cellular glucose utilization.