phosphorus-radioisotopes and Brain-Injuries

This paper further characterizes the response to axotomy of mouse transcallosal cortical neurons, a population of neurons that seems to be particularly refractory to regeneration. Mouse transcallosal cortical neurons did not upregulate mRNA for the growth-associated protein alpha 1-tubulin following axotomy, even when the axonal distance from injury to cell body was only 100-300 microns. Previous experiments had found no upregulation of another growth-associated protein, GAP-43, by transcallosal neurons following axotomy 1-2 mm from the cell body. These latest results establish that this population of neurons fails to respond to axotomy even when it is extremely proximal and that this failure is not a peculiarity specific to one growth-associated protein but is indicative of a generally poor regenerative response.

Topics: Animals; Axotomy; Brain Injuries; Cerebral Cortex; Corpus Callosum; Fluorescent Dyes; In Situ Hybridization; Mice; Mice, Inbred Strains; Nerve Regeneration; Oligonucleotides; Phosphorus Radioisotopes; Pyramidal Cells; Tubulin

Irreversible tissue injury following central nervous system trauma is believed to result from both mechanical disruption at the time of primary insult, and more delayed "autodestructive" processes. These delayed events are associated with various biochemical changes, including alterations in phosphate energy metabolism and intracellular pH. Using 31P NMR, we have monitored the changes in phosphorus energy metabolism and intracellular pH in a single hemisphere of the rat brain over an 8-h period following graded, traumatic, fluid percussion-induced brain injury. Following trauma the ratio of phosphocreatine to inorganic phosphate (PCr/Pi) declined in each injury group. This decline was transitory with low injury (1.0 +/- 0.5 atm), biphasic with moderate (2.1 +/- 0.4 atm) and high (3.9 +/- 0.9 atm) injury, and sustained following severe injury (5.9 +/- 0.7 atm). The initial PCr/Pi decline in the moderate and high injury groups was associated with intracellular acidosis; however, the second decline occurred in the absence of any pH changes. Alterations in ATP occurred only in severely injured animals and such changes were associated with marked acidosis and 100% mortality rate. After 4h, the posttraumatic PCr/Pi ratio correlated linearly with the severity of injury. We suggest that a reduced posttraumatic PCr/Pi ratio may be indicative of altered mitochondrial energy production and may predict a reduced capacity of the cell to recover from traumatic injury.

Topics: Animals; Blood Gas Analysis; Blood Pressure; Brain Injuries; Energy Metabolism; Hydrogen-Ion Concentration; Magnetic Resonance Spectroscopy; Male; Nervous System; Phosphates; Phosphorus Radioisotopes; Rats; Rats, Inbred Strains

Cerebrospinal fluid (CSF) contains two groups of proteins that bind tightly to DNA and to polyriboguanylic acid, respectively. In certain diseases the amounts of a given nucleic acid bound by a constant volume of CSF may increase, while in others the amount of such proteins may be reduced. Binding of polyriboguanylic acid increased in CSF samples from patients with brain tumors, stroke, multiple sclerosis, and communicating hydrocephalus, but it significantly decreased in CSF samples from patients with obstructive hydrocephalus. These increases may or may not be proportional to the rise in total CSF proteins characteristic for these diseases. Elevated binding of DNA was observed in samples from patients with hydrocephalus, epilepsy, and cortical atrophy. The technique described may be applicable to the diagnosis of a variety of diseases of the central nervous system.

Topics: Alcoholism; Astrocytoma; Brain Diseases; Brain Injuries; Brain Neoplasms; Carcinoma; Cerebrospinal Fluid Proteins; Cerebrovascular Disorders; Child, Preschool; DNA; Epilepsy; Female; Guanine Nucleotides; Headache; Humans; Hydrocephalus; Meningioma; Middle Aged; Multiple Sclerosis; Neurilemmoma; Phosphorus Radioisotopes; Polynucleotides; Protein Binding; Schizophrenia; Tritium

Topics: Biological Transport; Blood-Brain Barrier; Brain Injuries; Infarction; Phosphorus; Phosphorus Radioisotopes; Phosphorus, Dietary; Radioactivity