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Biomedical subjects

M S Albin

Publications and source records attributed to M S Albin.

At least 109 records · Page 6Linked to original sources
PubMed1965

Brain transplantation: prolonged survival of brain after carotid-jugular interposition.

Six isolated canine brains were successfully transplanted for 6 hours to 2 days to the cervical vasculature of dogs. Viability was shown by electrocortical activity and significant uptakes of oxygen and glucose, with production of carbon dioxide. Cerebral blood flows, temperatures, and pressures of the cerebral homograft were continuously monitored by way of an implantable recording module.

Animals↗
PubMedDate not supplied

Programmed management of acute cervical cord trauma.

Results in ten patients admitted with the diagnosis of complete traumatic quadriplegia and with fracture-dislocation of the cervical spine are reviewed. Emphasis is placed on aggressive emergency surgical treatment of these lesions such as tracheostomy, laminectomy and cord cooling, incorporated into a detailed protocol of overall management.

Accidents, Traffic↗
PubMedDate not supplied

Quantification of cerebral infarct size by creatine kinase BB isoenzyme.

Creatine Kinase BB isoenzyme (CKBB) has been shown to rise in the serum and CSF following acute cerebral injury. To test the hypothesis that brain infarct size could be estimated from the appearance and disappearance of CKBB in the serum and CSF, strokes of varying size were produced in twelve mongrel dogs by silastic emboli. The rate of disappearance, Kd of CKBB (-.00732 +/- 0.001 min-1 mean +/- SE, N = 8) was determined by injecting purified CKBB (25 IU) intravenously then measuring its disappearance. Following the embolic stroke, serum samples were taken hourly for 24 hours and then at intervals for up to 160 hours for measurement of CKBB by radioimmunoassay until the animals were sacrificed. The brains were then removed, fixed in formalin, cut in 2 mm sections and photographed. The area of the infarct was measured using high pad digitizer interfaced with an Apple computer. The infarct size was then calculated from the area and thickness. Using a one-compartment mathematical model, the infarct size was estimated from the amount of CKBB appearing in the serum, the Kd of CKBB, and the amount of CKBB depleted from tissue. The computed infarct size correlated well (r = 0.94) with the measured infarct size. This model may have value in testing therapeutic modalities in the intact animal.

Animals↗
PubMedDate not supplied

Autoregulation of spinal cord blood flow: is the cord a microcosm of the brain?

The autoregulatory capability of regional areas of the brain and spinal cord was demonstrated in 18 rats anesthetized with a continuous infusion of intravenous pentothal. Blood flow was measured by the injection of radioactive microspheres (Co57, Sn113, Ru103, Sc46). Blood flow measurements were made at varying levels of mean arterial pressure (MAP) which was altered by neosynephrine to raise MAP or trimethaphan to lower MAP. Autoregulation of the spinal cord mirrored that of the brain, with an autoregulatory range of 60 to 120 mm Hg for both tissues. Within this range, cerebral blood flow (CBF) was 59.2 +/- 3.2 ml/100 g/min (SEM) and spinal cord blood flow (SCBF) was 61.1 +/- 3.6. There was no significant difference in CBF and SCBF in the autoregulatory range. Autoregulation was also demonstrated regionally in the left cortex, right cortex, brainstem, thalamus, cerebellum, hippocampus and cervical, thoracic and lumbar cord. This data provides a coherent reference point in establishing autoregulatory curves under barbiturate anesthesia. Further investigation of the effects of other anesthetic agents on autoregulation of the spinal cord is needed. It is possible that intraspinal cord compliance, like intracranial compliance, might be adversely affected by the effects of anesthetics on autoregulation.

Anesthesia, Intravenous↗
PubMedDate not supplied

Evoked potential changes during brain retraction in dogs.

Brain retraction and induced hypotension are surgical adjuncts capable of compromising cerebral blood flow. To evaluate their effects upon brain function, cortical evoked potentials, neurological status and cortical histological changes were determined as a function of graded levels of brain retractor and systemic perfusion pressure in the dog. Somatosensory evoked potentials recorded from the site of application of brain retraction showed a decrement as a function of both the amount of retraction pressure and the systemic perfusion pressure. An electrode distant from the retractor site showed similar, though reduced and more variable changes in amplitude. For higher levels of brain retractor pressure, induced hypotension to 50 mm Hg systemic perfusion pressure produced greater reductions in evoked potentials than in normotensive subjects. It was demonstrated that a reduction of 50% of the evoked potential amplitude after sixty minutes brain retraction signaled, with high probability, the occurrence of postoperative sensory and/or motor deficits and cortical histopathology. It was concluded that cortical evoked potentials represent a reliable indicator of the functional effects produced by applied cortical retraction pressure at several levels of systemic perfusion pressure. It was suggested that the recording of evoked potentials would prove most useful during neurosurgical procedures employing induced hypotension and brain retraction.

Animals↗
PubMedDate not supplied

Air embolism during trans-sphenoidal pituitary operations.

Doppler ultrasonic cardiac monitoring of patients undergoing trans-sphenoidal pituitary operations in the semisitting position has revealed the occurrence of venous air embolism in 3 of 31 consecutive cases. One such case is presented. Air may be drawn into the venous system whenever a gradient exists between the site of operation and the right heart. During trans-sphenoidal operations the most likely portals of venous air entry include the intercavernous connections within the sella, venous channels through nonpneumatized bone, inadequately sealed subnasal vessels, and vascularized metastatic tissue in the pituitary. Because the potential for morbidity and mortality from air embolism is so great, rapid diagnosis with the Doppler unit and prompt treatment, including aspiration of air from the right atrial catheter, administration of 100% oxygen, performance of the Valsalva maneuver, saline irrigation of the wound, and hemostasis of open vessels, are essential. Technetium-macroaggregated albumin (TEMAA) lung scans are helpful in postoperative verification of venous air embolism.

Adenoma↗