The role of the coagulation cascade in brain edema formation after intracerebral hemorrhage

Summary The coagulation cascade has a potential role in brain edema formation due to intracerebral hemorrhage. In this study blood and other solutions were injected stereotactically into the right basal ganglia in rats. Twenty-four hours following injection, brain water and ion contents were measured to determine the amount of brain edema. Intracerebral blood resulted in an increase in brain water content. The amount of brain edema surrounding the intracerebral hematoma was reduced by a thrombin inhibitor Na-(2-Naphthalenesulfonylglycyl)-4-amidino-DL-phenylalaninepiperidide, (-NAPAP) infused into the hematoma after the clot had been allowed to solidify. The inhibitor did not alter the actual size of the clot mass. An artificial clot composed of fibrinogen, thrombin, and styrene microspheres also produced brain edema. A fibrin clot led to edema formation even in the absence of mass effect provided by the microspheres. The single component responsible for production of brain edema in all these models was thrombin. The edema was formed in response to a fibrinogen-independent pathway. These results indicate that the coagulation cascade is involved in brain edema that develops adjacent to an intracerebral hematoma.     

Transpedicular reduction and stabilization for postlaminectomy lumbar instability

Summary This study retrospectively reviewed the outcomes of 17 patients with postlaminectomy lumbar instability treated by transpedicular reduction and stabilization. The criteria of instability were defined strictly by both the clinical symptom of instability catch and the radiological findings that fulfilled Nachemson's criteria. Low back pain and/or sciatica that interfered largely with the patients' work or quality of life were the indications for this treatrment. All the operations were performed by one surgeon with the same spinal instrumentation system — AO internal fixator. The follow-up period was between 16 and 36 months (mean 24 months).Face to face questionnaire revealed that this treatment modality is encouraging. Fourteen patients (82%) had complete or nearly complete relief from all the pre-operative symptoms. Two (12%) had partial relief of the symptoms that required a subsequent discectomy or wider laminectomy. Only one case (6%) with osteoporosis remained unchanged after the operation. On the follow-up radiographs, sixteen patients (94%) showed good alignment and solid arthrodesis of the treated motion segment. These radiological findings correlated quite well with the absence of the clinical symptom of instability catch.A common, but acceptable, complication found in this series was a variable degree of low back stiffness secondary to the instrumentation. Fracture of the screw was found in one patient and pull out of the screw was found in another patient. However, they did not elicit detectable symptoms.Osteoporosis, concomitant disc herniation and persistent spinal stenosis at/or adjacent to the operated level were the three main factors that may contribute to unsatisfactory results secondary to this treatment. These problems remain to be resolved in thp future.     

Analysis of segmental phosphate absorption in intact rats. A compartmental analysis approach.

Available information supports the dominance of the proximal intestine in inorganic phosphate (Pi) absorption. However, there is no strategy for analyzing segmental Pi absorption from a spontaneously propelled meal in an intact animal. We propose a solution using compartmental analysis. After intragastric administration of a 32P-labeled Pi liquid meal containing a nonabsorbable marker, [14C]polyethylene glycol (PEG), rats were killed at 2, 10, 20, 30, 60, 120, and 240 min. The gastrointestinal tract was removed and divided into seven segments, from which 32P and [14C]PEG were recovered. Data was expressed as a percentage of the dose fed, i.e., (32P[in segment] divided by 32P[fed]) and [14C]PEG[in segment] divided by [14C]PEG[fed]), respectively. A compartmental model was constructed and the rate constants for intersegmental transit and segmental absorption were estimated. The "goodness of fit" between the simulated model and the actual data indicates the estimated rate constants reflect in vivo events. The duodenum, with the highest transit and absorption rates, accounted for a third of the total absorption. However, the terminal ileum, with a lower absorption rate but a longer transit time, absorbed an equal amount of Pi. This approach allows the analysis of the mechanism and the regulation of Pi absorption under more authentic in vivo conditions.     

Prevalence of eye disorders among the elderly in Los Angeles

A series of 431 vision screening records of seniors 55 years of age and older were analysed. Patients were examined by the UCLA Mobile Eye Clinic at two senior centers in the Los Angeles area, between the years 1982 and 1990. Sixty-eight percent of patients were females and 32% were males. The mean (+/-S.D.) age was 69 (+/-7.5) years. Common diagnoses were refractive errors (65.2%) and impaired visual acuity (37.0%). The prevalences of refractive errors were: hyperopia, 24.8%; myopia, 10.4%; presbyopia, 54.1%; and astigmatism, 31.8%. In most patients (94.0%), impaired visual acuity was corrected by spectacles. The prevalence of cataract was 29.5% and age-specific prevalences of cataract increased with age. The prevalences of other eye disorders were as follows: glaucoma, 6.3%; diabetic retinopathy, 1.2%; and macular degeneration, 5.1%. This study highlights the degree of ophthalmic disorders identified by vision screenings in the elderly population in senior centers; our results are consistent with previously reported studies of eye diseases in the elderly.     

A case of "voluntary nystagmus" and head tremor.

A 24-year-old woman presented with nystagmus and head tremor. Both were transient and could be executed simultaneously at different frequencies of oscillation. It is unusual for these two movements, which can be voluntary, to occur together. Suspicions of an acquired disease were not confirmed on further investigation using DC-coupled electro-oculography and angular accelerometry, and on an admission by the patient that the nystagmus could be voluntary. Voluntary nystagmus can become semi-automatic and a patient may be able to simulate more than one "involuntary movement" simultaneously yet at different frequencies.     

Group A meningococcal disease in the U.S. Pacific Northwest: epidemiology, clinical features, and effect of a vaccination control program

In 1975 an outbreak of group A meningococcal disease began in Seattle, Washington, and cases subsequently were recognized throughout the Pacific Northwest. Nearly one-half of the affected persons were Native Americans; two-thirds were alcohol abusers and/or habitués of skid road communities. In Seattle, group A meningococci colonized asymptomatic persons only if these individuals had contact with skid road (P = .006). The epidemic strain may have spread from American Indians in Manitoba, Canada. Traditional migration routes connect the two populations; asymptomatic American Indians on reservations in Washington carried group A meningococci. Vaccination programs were undertaken in four cities but only after cases occurred. In Seattle, vaccination reached 80% of the target population and was associated with a significant decrease in incidence of the disease, but cases recurred after the program ended. The social habits of skid road communities, combined with the "case-triggering" approach to, and premature termination of, vaccination programs, may have resulted in 56% of regional cases occurring after the start of the vaccination program in Seattle.     

Modulation of sensitivity to natural killer cell lysis after in vitro explantation of a mouse lymphoma.

On the basis of studies indicating that natural killer (NK) cells of the mouse can selectively kill certain syngenetic, allogeneic, and xenogeneic tumor cells in short-term Cr release assays and that cell lines established in vitro are more sensitive than the corresponding ascites tumor cells passaged in vivo, the kinetics of the modulation to increased sensitivity was studied after in vitro explanation of the A/Sn mouse-derived YAC ascites lymphoma. Sensitivity to NK lysis appeared after 3 weeks of culturing and reached the level of the continuously cultured line after 2 months. With the more sensitive competition assay, a change could be demonstrated as early as 2--24 hours of culture. The expression of the Moloney murine leukemia virus-determined, cell-surface antigen, measured by quantitative absorption with intact cells, increased in parallel with the NK sensitivity. In contrast, the H-2 alloantigen concentration decreased during in vitro culture.