Occupational stress in migraine is weekend headache a myth or reality?

To determine whether or not the frequency of migraine attacks increased at weekends in employed patients and if so, whether or not this was related to the type of migraine, 35 female patients prospectively recorded the presence or absence of migraine attacks daily over a six-week period. They were also asked to estimate the frequency with which emotional factors predisposed to their migraine attacks and to provide details of their occupation. A diagnosis of common (migraine without aura) or classical migraine (migraine with aura) was made according to both the criteria of the Ad Hoc Committee on the Classification of Headache and those of the International Headache Society. Eleven percent and 6% of patients, respectively, felt that emotional factors "usually" or "always" predisposed to migraine attacks. There was no significant increase in the frequency of migraine attacks at weekends in either the total group or in the employed patients. Similarly, the type of migraine made no difference to the results. There was therefore no evidence for a delayed onset of migraine at weekends related to the weekday stress of employment.     

The personality structure of 'normal' volunteers

The personality structure of 65 volunteers for a Phase 1 drug trial was examined using the Eysenck Personality Questionnaire. It revealed a common pattern of high extroversion, low neuroticism and psychoticism. The reasons why the study might attract such people are examined and the structure compared with those that take drugs that might have 'strange or dangerous effects'. The likely forms of bias that this personality structure may bring to the trial are explored.     

Liberation of an interaction domain from the phosphotransfer region of CheA, a signaling kinase of Escherichia coli.

The CheA protein of Escherichia coli is a histidine autokinase that donates its phosphate groups to two target proteins, CheY and CheB, to regulate flagellar rotation and sensory adaptation during chemotactic responses. The amino-terminal third of CheA contains the autophosphorylation site, determinants needed to interact with the catalytic center of the molecule, and determinants needed for specific recognition of its phosphorylation targets. To understand the structural basis for these activities, we examined the domain organization of the CheA phosphotransfer region by using DNA sequence analysis, limited proteolytic digestion, and a genetic technique called domain liberation. Comparison of the functionally interchangeable CheA proteins of E. coli and Salmonella typhimurium revealed two extensively mismatched segments within the phosphotransfer region, 22 and 25 aa long, with sequences characteristic of domain linkers. Both segments were readily susceptible to proteases, implying that they have an extended, flexible structure. In contrast, the intervening segments of the phosphotransfer region, designated P1 and P2 (roughly 140 and 65 aa, respectively), were relatively insensitive, suggesting they correspond to more compactly folded structural domains. Their functional properties were explored by identifying portions of the cheA coding region capable of interfering with chemotactic behavior when "liberated" and expressed as polypeptides. P1 fragments were not inhibitory, but P2 fragments blocked the interaction of CheY with the rotational switch at the flagellar motor, leading to incessant forward swimming. These results suggest that P2 contains CheY-binding determinants which are normally responsible for phosphotransfer specificity. Domain-liberation approaches should prove generally useful for analyzing multidomain proteins and their interaction targets.     

Railways of the nineties

What killed the railways was that they were run by people who really liked choo-choos. This also is the Achilles' heel of hospitals. They are run by people fascinated with big white buildings and all they contain.     

Undifferentiated embryonal sarcoma of the liver: results of clinical management in one center

PURPOSE: This study was undertaken to review the authors' clinical experience with undifferentiated embryonal sarcoma of the liver (UES) in children, focusing on the clinical presentation and results of treatment. METHODS: A retrospective analysis of all children who have undergone treatment for UES during the 15-year period from 1984 through 1998 was performed. RESULTS: Seven patients (4 boys and 3 girls) ranging in age from 20 months to 12 years at the time of diagnosis were identified. All presented with large abdominal masses and normal liver function test results. All underwent complete tumor resection; trisegmentectomy was required in 4 of these cases. All patients received postoperative chemotherapy. Two patients suffered tumor recurrence at 12 and 29 months; both of these patients died of their disease. Another patient died of complications related to chemotherapy. The other 4 patients are alive with no evidence of disease after 19 to 150 months' follow-up. CONCLUSIONS: Undifferentiated embryonal sarcoma of the liver presents as a large hepatic tumor. Operative resection is difficult, but combined with adjuvant chemotherapy offers the best hope for cure.     

Cultured motor neurons possess calcium-permeable AMPA/kainate receptors

We examined the biology of AMPA/kainate-induced motor neuron degeneration using dissociated spinal cord cultures and motor neuron-specific antibodies which enable characterization of individual motor neurons in culture. Cobalt, which is thought to pass through Ca2+-permeable AMPA/kainate receptors following kainate exposure, labeled motor neurons in spinal cord cultures. The analysis of AMPA subunit distribution in dissociated motor neurons revealed a unique pattern of glutamate receptor (GluR) subunits in those cells; the GluR1 subunit was found in all spinal cord neurons, but the GluR2 subunit was not found in identified dissociated motor neurons. These data suggest that selective sensitivity of motor neurons to non-NMDA receptor activation is due, at least in part, to the presence of Ca2+-permeable AMPA/kainate receptors.     

Syncope-related trauma: rationale and yield of diagnostic studies

BACKGROUND: Syncope occasionally occurs in trauma patients. The most appropriate and cost-effective evaluation for such patients is unknown. METHODS: Trauma patients admitted to a Level I trauma center with a diagnosis of syncope or possible syncope between 1988 and 1994 were reviewed. History, physical examination, and past medical history were noted, as were the results of tests done as part of the syncope evaluation. RESULTS: Eighty-eight patients were reviewed; 45% had been injured in falls. Thirteen patients who remembered their entire injury and denied syncope as a cause had negative evaluations. History, physical examination, and admission laboratory values were helpful in diagnosis 59% of the time. Subsequent evaluation provided useful diagnostic information 30% of the time. No patients with normal admission electrocardiograms (EKGs) had cardiac causes for their syncope. CONCLUSIONS: (1) Patients with possible syncope without loss of consciousness require no further evaluation. (2) A cerebrovascular evaluation should be the initial diagnostic approach in patients with signs and symptoms suggestive of stroke or transient ischemic attack. (3) Possible syncope patients with normal admission EKGs should undergo computed tomography of the head and electroencephalography. Those with abnormal EKGs should undergo echocardiography.