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Biomedical subjects

M Ball

Publications and source records attributed to M Ball.

At least 109 records · Page 6Linked to original sources
PubMed1982

Normal computed tomograms in acute head injury: correlation of intracranial pressure, ventricular size, and outcome.

To assess the predictive value of a normal computed tomographic (CT) scan obtained shortly after head injury, we reviewed all cases of patients with acute closed injury seen at the North Carolina Baptist Hospital over a 42-month period for whom initial CT scanning and continuous intracranial pressure (ICP) monitoring had been done. Of 160 patients meeting those criteria, the initial CT scan was interpreted as normal in 17 patients, all of whom had a Glasgow coma scale score of 9 or less. Of those 17 patients, 7 had elevated ICP (higher than 25 mm Hg) and required mannitol. Six of the 7 had a major pulmonary injury. From the 27 CT scans of the 17 patients, we calculated an inverse cella media index and compared it to previously published standards in an attempt to delineate more quantitatively the "slit ventricles" often seen in cases of head injury. Two patients died of extracranial injuries; I had severe disability and 2 had moderate disability - all related to extracranial factors. The remaining 12 made good recoveries. From these findings, we conclude that a normal initial CT scan in patients with closed head injury and pulmonary injury does not preclude increased ICP (and thus should not preclude ICP monitoring) and that patients with closed head injury and a normal initial CT scan in the absence of associated extracranial injuries should make a good recovery.

Adolescent↗
PubMed1979

The trapped temporal horn: a trap in neuroradiological diagnosis.

Although the advent of computerized cranial tomography (CT) has decreased the number of pneumoencephalograms performed for the diagnosis of hydrocephalus and lesions of the posterior fossa, brain stem, and ventricles, there are some patients in whom pneumoencephalography should still be done because it adds valuable information to that obtained with CT. When the temporal horn becomes obstructed, the choroid plexus and ependymal surface "upstream" from the obstructing mass continue to produce cerebrospinal fluid (CSF). The temporal horn can thus enlarge enough to appear as a mass on CT because of its reduced x-ray attenuation coefficient. Pneumoencephalography is effective in this situation because air will flow past a mass that obstructs CSF and because the ventricular system dilates during pneumoencephalography. When pneumoencephalography is used in a patient with a trapped temporal horn, the partially trapped horn may enlarge approximately 24 hours later. With that precaution in mind, the neurosurgeon should find pneumoencephalography to be a useful adjunct to CT in delineating the cause of a trapped temporal horn. In the three patients reported here CT had indicated a unilateral trapped temporal horn; pneumoencephalography confirmed that finding and demonstrated both the location and the nature of the lesion. One patient had a Grade II astrocytoma fungating into the atrium of the right lateral ventricle, one had a mass extending into the right ventricle from the medial and superior ventricular wall with nodular encroachment on the ventricle, and one had a meningioma in the atrium of the right lateral ventricle.

Aged↗
PubMed1979

A dosage response curve for the one rad range: adult risks from diagnostic radiation.

Most exposure to low-level ionizing radiation, both diagnostic x-rays and nuclear radiation, occur in the range between 100 milirads and 10 rads--the "one rad range". In the past, the estimates of hazards in this range have been obtained by linear extrapolation from data on persons who were exposed to much higher dosages, generally in the centirad range used in radiotherapy of non-malignant disease. This article presents the first dosage response curve for the one rad range ever to be developed directly from data on men exposed to ordinary diagnostic radiation. The findings are based on approximately 220 men with non-lymphatic leukemia and more than 270 random-sample controls from the Tri-State Survey. The new findings suggest that the estimates previously obtained by extrapolation from high dosage levels to low dose levels underestimate the actual hazards by an order of magnitude. The new dosage response curves indicate that linear extrapolation fails because it disregards the subgroups in the general population that are particularly vulnerable to x-ray. There are immediate implications concerning the use of medical x-rays in screening or for routine purposes. The past risk-benefit calculations are based on extrapolative estimates and require drastic revision. Uses of x-ray which were previously marginal are now clearly counterindicated.

Adolescent↗
PubMed1978

Preliminary report on radiation and heart disease.

Using data from the Tri-State and a mathematical model, the hypothesis that low levels of diagnostic radiation can produce both leukemia and heart disease has been tested. The range of radiation considered is within a factor of 10 of 5 rads (0.5-50 rads). Even at the lowest levels, an estimated 5% of the persons exposed suffer damage to the DNA which is subsequently expressed as heart disease or leukemia. The risk of heart disease in an affected group is roughly tripled and there is a 10-fold increase in the risk of leukemia according to preliminary estimates.

Aged↗
PubMed1977

Interrelationship in the regulation of pyruvate dehydrogenase and adenine-nucleotide translocase by palmitoyl-CoA in isolated mitochondria.

Full activation of rat liver pyruvate dehydrogenase in vitro by ADP was prevented by palmitoyl-CoA at a concentration sufficiently low to preclude substrate effects secondary to its oxidation by mitochondria. Activation of pyruvate dehydrogenase by ADP in livers of fat-fed rats was less than in the control animal. The results are consistent with the experiments demonstrating an inhibition of adenine nucleotide translocase and on increased intramitochondrial ATP/ADP ratio by palmitoyl-CoA which could account for the effect on pyruvate dehydrogenase. Inactivation of brain pyruvate dehydrogenase by ATP was also diminished by palmitoyl-CoA indicating that the effect was at the level of the adenine nucleotides rather than at either the pyruvate dehydrogenase kinase or phosphatase enzymes.

Adenosine Diphosphate↗