Auditory evoked potentials as probes of hemispheric differences in cognitive processing

The amplitude of auditory evoked potentials recorded from the cerebral hemispheres to pairs of task-irrelevant tones was related to differential hemispheric engagement in ongoing cognitive activity (for example, verbal versus musical). The hemisphere hypothesized to be most engaged in the ongoing cognitive task, as compared to the unengaged hemisphere, produced a greater potential difference between the temporal and reference electrode to the second of the tone pairs. These findings are related to "fast habituation" and "recovery cycle.".

Effects of dexamethasone and betamethasone on in vitro cultures from human astrocytoma

Cultures of human astrocytoma have been derived by collagenase digestion and are presumed, from their aneuploid karyotypes, to be predominantly neoplastic. Early passage cultures in proliferative phase have been cloned in the presence of dexamethasone and betamethasone, both commonly used in management of patients with brain tumours. These steroids raise both the cloning efficiency and the proliferative capacity of cells within each clone. Inhibition was detected only in very high steroid concentrations (25-50 microng/ml). Since these concentrations are unlikely to be attained in vivo it is concluded that anticipated physiological levels of these steroids enhance cell survival at low densities in culture. The significance of this in vivo is discussed.

Lactic dehydrogenase isoenzymes following head injury

Serial levels of lactic dehydrogenase (LDH) isoenzymes have been measured in 92 neurosurgical patients with damaged brains, including 77 suffering from head injury. Serum LDH isoenzymes 1 and 2 rise in the injured group and generally reflect the degree of parenchymal brain damage. The method has possible diagnostic applications, as well as some prognostic use.

The effect of trans-urethral surgery on penile erections in spinal cord injury patients

The effect of transurethral surgery on penile erections in 62 spinal cord injury patients is reviewed. In a group of 43 patients with preoperative erections, 19 noticed no change in the pattern of erections. Twenty-four of the 43 patients notice either a diminution or total disappearance.

The use of halothane anaesthesia to control autonomic hyperreflexia during trans-urethral surgery in spinal cord injury patients

Forty-five spinal cord injury patients undergoing trans-urethral surgery were anaesthetised using a mixture of nitrous oxide and halothane in oxygen. The use of halothane to control the hypertensive manifestations of surgically induced autonomic hyperreflexia is discussed.

Urodynamic observations following spinal trauma

A method of the urodynamic investigation of paraplegic and quadriplegie patients is described. Serial measurements of the urethral pressure profile in patients with developing reflex micturition demonstrate a rising pressure at the external urethral sphincter with time following spinal trauma. Patterns of micturition with detrusor-sphincteric imbalance are described in patients with both early and well-established reflex micturition.

Congenital pericardio-peritoneal communication with herniation of omentum into the pericardium. A rare cause of cardiomegaly

Images

Concentration-Gradient-Driven Convection: Experiments

Concentration-gradient-driven convection was studied by measurement of the rate of dissolution of the lower face of a KCl single crystal in contact with various solvents. The rate of mass transfer due to convective stirring appeared to follow the Rayleigh number to the one-third power law. A regular pattern of etch pits due to the convective stirring action was observed in the crystal face after exposure to water for 5 minutes. Schlieren photographs of the early stages of dissolution showed a regular pattern of spikes having approximately the same dimensions as the etch pits in the crystals.