Paul T. Turner

Ultrastructure of exogenous peroxidase in cerebral cortex

Abstract Protein uptake and transport and the intercellular spaces were studied electron microscopically in normal rabbit, cat and monkey cerebral cortex using horseradish peroxidase (HRP) as a cytochemical tracer. Extensive endocytosis and accumulation of tracer were seen as a result of delivering high concentrations of HRP into the intercellular space followed by long observation experiments, up to 120 h. Incorporation of HRP into neurons and their processes after a single application was studied by following the progress of neuron organelle labeling; the disappearance of tracer from these structures gave new information on the optimal times when HRP could be seen as a cellular tracer in cortical neurons. Neurons and their processes demonstrated a remarkable facility to take up peroxidase in coated invaginations and vesicles and accumulate it in multivesicular and other lysosomal bodies. The first structures labeled were coated vesicles, synaptic vesicles, sacs and tubules. HRP disappeared from the intercellular space after 24 h, and coated vesicles and synaptic vesicles no longer contained it at this time. Sacs and tubules were free of tracer by 48 h. Multivesicular bodies contained HRP after 30 min and lost all label between 72–96 h. Dense bodies became labeled after 1.5 h, and remained labeled until 96–120 h. Evidence of axon transport of the tracer was added to that extant on this pathway.

Left thalamic hemorrhage with dysphasia: A report of five cases

Abstract A specific type of “thalamic speech” is being recognized with increasing frequency. Paucity of spontaneous speech, fading vocal volume, anomia, perseveration, and neologisms, with intact comprehension and word repetition, characterize the speech disorder associated with thalamic lesions. Nine cases of left thalamic hemorrhage and speech disturbance have been reported previously. This report details the speech, neurological, and neuroradiological findings in five additional cases of thalamic hemorrhage with dysphasia.

A complication of nasogastric intubation: intracranial penetration.

A patient with severe maxillofacial trauma had a nasogastric tube inserted into the intracranial cavity. Two such case reports were found in the literature and in both instances the patients expired. The present patient is believed to be the first who survived intracranial passage of a nasogastric tube.

Effect of pentobarbital on uptake of horseradish peroxidase by rabbit cortical synapses

Abstract The presynaptic membrane response of rabbit cortical synapses to different doses of pentobarbital anesthesia was studied ultrastructurally by measuring the uptake of an extracellular marker, horseradish peroxidase, into presynaptic bouton vesicles. Uptake of peroxidase after a pentobarbital dose of 25 mg/kg was virtually unchanged from uptake observed in the absence of barbiturate anesthesia. After a pentobarbital dose of 40 mg/kg, however, a significant decrease in the number of peroxidase labeled vesicles was observed. Further increment in the barbiturate dose resulted in fewer labeled vesicles and at a dose of 150 mg/kg, no labeled presynaptic organelles were detected. These observations suggest that pentobarbital exerts an inhibitory effect on vesicular membrane transport and synaptic vesicle turnover; thus, one way it may alter synaptic transmission in rabbit cortex is by a direct action on the presynaptic bouton.

Generous craniectomy for Kleeblattschädel anomaly.

In the case presented, Kleeblattschädel, or cloverleaf skull deformity, was treated successfully with a two-staged, generous craniectomy. The pertinent aspects of this rare anomaly are reviewed in light of information from other cases described previously. The present case illustrates that an early surgical approach of subtotal calvariectomy may improve the commonly predicted poor prognosis in patients with Kleeblattschädel anomaly if the clinical severity of the disease is not immediately overwhelming.