Biomedical subjects

H F Young

Publications and source records attributed to H F Young.

131 records · Page 8Linked to original sources

PubMedDate not supplied

Methylprednisolone treatment in patients with brain tumors.

A study was made in 10 patients with brain tumors of the effect of methylprednisolone sodium succinate (Solu-Medrol) on clinical neurological status, intracranial pressure, and periventricular elastance. Significant clinical improvement and reduction in periventricular elastance both ocurred within 24 hours of starting treatment, whereas intracranaial pressure was not significantly reduced until the 2nd day of therapy.

Adenoma, Chromophobe↗

PubMedDate not supplied

Coma associated with flaccidity produced by fluid-percussion concussion in the cat. I: Is it due to depression of activity within the brainstem reticular formation?

This study is the first attempt to characterize neurological and behavioural consequences of fluid-percussion concussive head injury in the cat. Both animals initially anaesthetized by N2O as well as unanaesthetized, chronically prepared animals were subjected to injury. Injury with a fluid-pressure wave of 1.9-2.5 atm (duration 21-24 ms) produced a brief generalized areflexia. Following this initial response, injury greater than 2.1 atm frequently produced a period associated with hypotonia of postural muscles and suppression of postural motor responses (flaccidity). A close association between flaccidity and other indices of coma such as absence of eye-opening responses was noted. These consequences of injury can occur without fatal apnoae, circulatory collapse or overt intraparenchymal haemorrhages. This result suggests that mechanical stress predominantly restricted to the brain stem in fluid percussion may be sufficient, at least in the cat, to produce coma associated with flaccidity which has been previously documented for acceleration concussion. There was no evidence that fluid percussion produced EEG depression similar to the effects of lesions in the mesencephalic reticular activating system (RAS). Thus, depression of general levels of brain activity including those within the RAS seems not be necessary for production of this form of reversible coma.

Animals↗

PubMedDate not supplied

Coma associated with flaccidity produced by fluid-percussion concussion in the cat. II: Contribution of activity in the pontine inhibitory system.

In the preceding paper we reported that concussive levels of fluid-percussion head injury can produce transient flaccidity of postural muscles associated with other indices of coma. This reversible coma associated with flaccidity follows an initial period of generalized areflexia and occurs in the absence of EEG slow waves. The present study investigated the physiological mechanisms underlying the flaccidity following concussive head injury be recording dorsal and ventral root potentials of the spinal cord. Studies indicated that, during the initial period of generalized areflexia, afferent input transmission was depressed although the excitability of motoneuronal pools was increased. In contrast, during periods of flaccidity, spinal cord somatomotor functions were depressed while transmission of afferent inputs was recovering. Systematic transection of the brain stem showed that activity within structures lying between collicular and midpontine levels is necessary to produce this latter condition. Cholinergic activation of pontine inhibitory areas within this same region of the rostral pons can produce profound descending inhibitory influences on postural somatomotor function in conjunction with other features of coma including suppression of eye-opening responses. Such effects occur without EEG slow waves. Moreover, other data indicate that local rates of glucose utilization within this pontine inhibitory area increase following concussive head injury. Thus, it is possible that a predominance of activity within the pontine inhibitory area could provide at least one neural basis for the reversible comatose state following concussive head injury characterized by close association between flaccidity and other indices of coma. Possible relationships of these data to clinically observed features of concussion are discussed.

Animals↗

PubMedDate not supplied

Substance abuse and crime patterns among persons with traumatic brain injury referred for supported employment.

The present investigation examined the incidence of alcohol use, drug use and criminal behaviour among persons with traumatic brain injury referred for supported employment services. Primary caretakers of 74 consecutive referrals completed the General Health and History Questionnaire, the brief version of the Michigan Alcohol Screening Test, and the Quantity-Frequency-Variability Index. Pre-injury, a fifth of the sample were abstinent from alcohol and 66% were labelled as moderate or heavy drinkers. Post-injury alcohol use declined. Half of the sample were abstinent and 28% were moderate or heavy drinkers. Thirty-six percent reported illicit drug use pre-injury. Reportedly, post-injury drug use declined to an incidence of 4%. Nearly 20% of the sample had been arrested pre-injury and 10% were arrested post-injury. Implications for further research and programme development are discussed.

Activities of Daily Living↗

PubMedDate not supplied

Herpesvirus type 1 serum antibodies and brain tumors in humans.

Sixty-five patients underwent craniotomy for brain tumors; of these 35 had glioblastoma multiforme (GM). The GM cases, as a group, showed significantly higher serum titers for herpesvirus type 1 (HSV-1) neutralizing antibodies (NT) than the non-glioblastoma cases. Both the GM group and the pituitary adenoma group had high levels of HSV-1 serum antibodies with the enzyme-linked immunosorbent assay (ELISA). These data, combined with other evidence, lead us to speculate that HSV-1 infections may be associated with certain brain tumors in humans. However, coincidental causes for these elevated HSV-1 titers must be ruled out.

Adenoma↗