Blood pressure and heart rate changes in streptozotocin diabetic rats, with special reference to postural hypotension.

Blood pressure and heart rate changes were recorded on supine or prone head-up tilt and on carotid artery occlusion in normal and streptozotocin diabetic rats (65 mg/kg). In general supine tilt induced a larger blood pressure fall, slower blood pressure recovery from the fall and larger heart rate fall than prone tilt, both in normal and diabetic rats. Heart rate recovery from the fall was slightly larger in prone than in supine tilt in normal rats. The blood pressure fall and heart rate fall accompanying the tilt were statistically larger in diabetic than in normal rats. Furthermore, blood pressure recovery from the fall was statistically more rapid and larger in normal than in diabetic rats. The exaggerated blood pressure fall with the tilt of diabetic rats might correspond to postural hypotension. Blood pressure rise and heart rate rise with carotid artery occlusion were smaller in diabetic than in normal rats. Blood pressure changes with cervical sympathetic or vagus stimulation were almost the same in normal and diabetic rats. However, in diabetic rats such cervical autonomic nerve stimulation produced larger heart rate changes than in normal rats.     

Starch, gloves and extradural catheters

We have investigated contamination of extradural catheters during normal handling with starch powdered gloves. In the laboratory, extradural catheters were handled in sterile fields with both powdered and non-powdered gloves, simulating preparation for patient insertion. The catheters together with glove samples were then examined using a Zeiss 940 scanning electron microscope. Microscopy of samples revealed starch contamination of the catheters handled with powdered gloves, especially in the side hole areas. We conclude that extradural catheters may be contaminated easily by starch powder from surgical gloves. This powder may then be deposited into the extradural space. The effect of starch in the extradural space is not known but starch is known to cause inflammatory and granulomatous reactions in other parts of the body as well as being directly allergenic. Powder contamination of catheters may be avoided easily by the use of powder-free gloves and we feel that these should be used whenever possible.      

Middle-ear paraganglioma masquerading as traumatic facial nerve palsy.

We report the case of a 52-year-old female with middle-ear paraganglioma masquerading as a traumatic facial palsy, and describe the diagnostic steps and surgical treatment by the tympanomastoid approach.     

Hazardous chemicals: psychological dimensions of the health sequelae of a community exposure in Texas.

STUDY OBJECTIVE--A chemical spill from an oil refinery exposed the local community to more than 40,000 lb of highly toxic and corrosive hydrofluoric acid. A community based symptom prevalence study found an association between exposure and physical symptoms: the psychological impact of the disaster and its potential effect on the reporting of physical symptoms is examined here. DESIGN--The study used a population based survey design consisting of two phases: phase I, the exposure phase, and, phase II, the symptom prevalence phase. SUBJECTS--In phase I, information indicative of exposure was collected on 10,811 individuals in a door to door survey of a geographically defined area. In phase II, symptom prevalence information was gathered through in-person interviews with 2509 subjects selected from the phase I census in a sampling scheme that balanced across the exposure categories with regard to age, gender, and predisposition. The refusal rate in both phases was < 5%. MEASUREMENT AND MAIN RESULTS--Stepwise logistic regression analyses were used to assess the relative predictive importance of psychological variables and hydrofluoric acid exposure in explaining the reported physical symptoms two years after the disaster. The findings show a linear relationship between the level of hydrofluoric acid exposure and the degree of psychological stress two years after the accident. High exposure had a long term (more than two years) impact on physical health for some self reported symptoms, even after controlling for the psychological impact. Some physical symptom reports, however, were better explained by psychological status than by exposure to hydrofluoric acid. The physical symptoms for which exposure was the major predictor were those for which the biological plausibility of a relationship with hydrofluoric acid exposure was direct. CONCLUSIONS--Measures of psychological status should be included in symptom studies of health sequelae to man-made disasters so that the physical effects of exposure can be more accurately assessed.     

Three-dimensional MR vascular imaging of the spine using gadolinium-DTPA.

To investigate the fine vascular structures in the spinal and paraspinal region, the authors performed three-dimensional GRASS scanning after the administration of contrast material. The scan sequence was sagittal volume scan, TR/TE 100/16, with a flip angle of 45 degrees. First-order gradient moment nulling was employed. Four normal volunteers and 31 patients were studied. Using this technique, longitudinal anterior epidural veins and vertebral arteries were clearly identified. Paraspinal fine vessels of slow to moderate flow, including dilated anterior spinal artery, radiculo-medullary vein, and perimedullary coronal venous plexus, were demonstrated in pathological cases. In addition, with processing of the volume data set, phlebographic projection images of the ladder-shaped anterior epidural venous system could be generated. This method provided more detailed information on epidural and intradural vessels than conventional MR imaging.     

Cerebrovascular reserve capacity in ischemia due to occlusion of a major arterial trunk: studies by Xe-CT and the acetazolamide test.

Classifications based on clinical and radiographic criteria have proved to be inadequate predictors of the course of cerebral ischemia or its response to therapy. In this study the cerebrovascular reserve capacity (CRC) of 46 patients with symptomatic cerebrovascular ischemia was studied by stable xenon-enhanced CT (Xe-CT) combined with the acetazolamide test. Fifteen patients had internal carotid artery (ICA) occlusion, 10 had ICA stenosis, 10 had middle cerebral artery (MCA) occlusion, and 11 had MCA stenosis. In the patients with chronic cerebral ischemia due to occlusive lesions of the ICA and MCA, the CRC was reduced most in those with MCA occlusion, followed, in descending order, by those with ICA stenosis, MCA stenosis, and ICA occlusion. Our results indicate that measurement of the CRC elucidates cerebral hemodynamic factors that cannot be detected by angiography in patients with chronic cerebral ischemia and that Xe-CT combined with the acetazolamide test is useful for this purpose.     

Specific MR imaging of human lymphocytes by monoclonal antibody-guided dextran-magnetite particles.

Human lymphocytes were labeled with biotinylated anti-lymphocyte-directed monoclonal antibodies, to which streptavidin and subsequently biotinylated dextran-magnetite particles were coupled. This labeling resulted in a strong and selective negative contrast enhancement of lymphocyte suspensions at 2.0 T, caused predominantly by the specific increase of R2 with a small but significant specific increase of R1. The R1 was found to decrease with increasing field strength. The immunolabeling procedure described here may be used for the selective signal depletion of target cells in MR imaging.     

Pain-related somatosensory evoked potentials following CO2 laser stimulation in peripheral neuropathies

Pain-related somatosensory evoked potentials (pain SEPs) following CO2 laser stimulation were examined in 30 patients with peripheral neuropathies, and the results were compared with clinical sensory findings. Pain SEP findings showed a significant correlation with the clinical impairment of pain sensation, but not with the impairment of deep sensations. In contrast, conventional electrically-stimulated SEPs (electric SEPs) showed a significant correlation with deep sensations, but not with the impairment of pain sensation. Examinations of both pain SEPs and electric SEPs, therefore, are considered to be very useful to evaluate physiological functions of sensory nerves in patients with peripheral neuropathies.