Early cerebral blood flow and computerized tomography in predicting ischemia after cerebral aneurysm rupture.

Cerebral blood flow (CBF) was measured during the 1st week of subarachnoid hemorrhage in 46 patients who were in a good clinical grade and had a proven ruptured intracranial aneurysm. The mean initial CBF in patients who developed cerebral ischemia was 42 ml/min-1/100 gm brain-1, which was significantly lower than in patients who did not develop cerebral ischemia (49 ml/min-1/100 gm brain-1). This reduced CBF was not secondary to raised intracranial pressure or angiographic spasm.

Sulfated glycosaminoglycan deposition and processing at the basal epithelial surface in branching and beta-D-xyloside-inhibited embryonic salivary glands.

We investigated whether the inhibition of proteoglycan synthesis and salivary branching morphogenesis by beta-D-xyloside was related to the deposition and processing of newly synthesized glycosaminoglycans at the basal epithelial surface that correlates with normal branching activity. Forty eight-hour cultures of control and 0.5 mM beta-xyloside-treated submandibular rudiments were labeled for 2 hr with [35S]sulfate and fixed and processed for autoradiography, immediately or after 2, 4, 6, or 8 hr of postlabeling chase in nonradioactive medium.

Improvement in injury induced hypocalcia by high-dose naloxone intervention.

Naloxone hydrochloride was used to re-establish normal calcium activities in the extracellular space of the injured spinal cord. The micromolar levels of calcium which occur immediately after injury were improved above control values by 1 h 30 min post-injury; normal activities occurred at 2 h 45 min. Such a restitution of ionic levels after injury may contribute to the beneficial effects of naloxone in traumatic injury.

Cysticercosis of the fourth ventricle. A classic presentation of an old scourge.

The clinical, neuroradiological, and pathological features of cysticercosis of the fourth ventricle, which occurred in a Cambodian immigrant, are reported. Comparisons between this case and Bruns' original description of cysticercosis of the fourth ventricle are made.

Extracellular calcium activity in the injured spinal cord.

The extracellular concentration of calcium ion was measured in canine spinal cord subsequent to spinal injury. In the control animal, we found that calcium activities changed little independent of electrode placement in the spinal cord, were stable during the 3 h necessary to make injury measurements, and were comparable to other estimates of calcium in the interstitial space. After injury, calcium activities decreased to micromolar levels that were incompatible with neural function.

Four neural circuit models and their role in the organization of voluntary movement.

Four neural circuit models and their role in the organization of voluntary movement are presented here. These circuits collectively control a ballistic type biped voluntary movement. The structure of each circuit, and its function is discussed.

O2 tension in the spinal cord of the avian embryo.

A small recessed-tip O2 microelectrode was used to construct frequency distributions of PO2 in the chicken embryonic spinal cord during the last week of development (15-20 days). PO2 was remarkably low and stable at a given spinal locus. Electrode movement led to little change in the absolute level of tissue PO2 for a given day in the development.

Isometric contractile properties and velocity of shortening during avian myogenesis.

Isometric twitch and tetanic contractile properties and velocity of unloaded shortening (V0) of whole avian posterior latissimus dorsi muscle (PLD) were examined between embryonic day 15 and the first 2 wk after hatching. The time to peak twitch force, time to half-relaxation of the twitch response, and time to half-peak tetanic force all change significantly during the final week in ovo but do not change during the first 2 wk ex ovo. Comparisons with previously published reports by others indicate that the twitch half-relaxation time at hatching is approximately the same as that of the adult PLD.

Medical management of patients following a ruptured cerebral aneurysm, with epsilon-aminocaproic acid, kanamycin, and reserpine.

Patients suffering from a subarachnoid hemorrhage who were admitted to the Neurosurgical Unit of the Royal Perth Hospital during the period 1971 to 1979 were assessed with regard to the effectiveness of preoperative treatment with epsilon-aminocaproic acid, kanamycin, and reserpine. Forty-two patients who were treated with epsilon-aminocaproic acid had a rebleed rate of 2.3% compared to 1 9.

Development of contractile properties in avian embryonic skeletal muscle.

The development of the twitch and tetanic responses of the embryonic chick posterior latissimus dorsi muscle has been studied during the last week in ovo. Normalized twitch and tetanic forces increased 3- and 12-fold, respectively, during this period. The changes in the kinetics of the twitch and tetanic responses differed during this developmental period.

Subarachnoid haemorrhage: epidemiology, natural history, and surgical treatment.

We analysed 360 patients who presented with a proven subarachnoid haemorrhage during the period 1971-78. The most common cause was a cerebral aneurysm (75%), with the anterior communicating artery being the most common site for a ruptured aneurysm. Overall mortality rate before surgical intervention was 28%.

Oxygen fields in specific spinal loci of the canine spinal cord.

Oxygen tension (PO2) measurements were made in the dog spinal cord with a small recessed-tip oxygen microelectrode. The use of vibration and specific marking techniques has allowed the elimination of tissue compression artifacts and the mapping of regional PO2 in the thoracic spinal cord. A symmetrical distribution of PO2 values can be shown for the lateral white funiculi; the gray matter and dorsal columns have multimodal distributions.

Compression of the tibial nerve by the tendinous arch of origin of the soleus muscle.

Details of 5 cases of surgically confirmed entrapment of the tibial nerve in the popliteal fossa are presented. In 4 cases the nerve was compressed beneath the tendinous arch of the origin of the soleus muscle. In 1 of these cases, thrombosis of a tributary of the popliteal vein with oedema of structures in the popliteal fossa and secondary compression of the nerve was found.

Acute modification of embryonic spinal cord activity induced by hypoxia.

The effects of acute environmental hypoxia on spinal cord polyneuronal activity throughout the later stages (14, 16 or 19 days) of chick incubation were studied. Bioelectrical activity was recorded in ovo from lumbosacral regions of the spinal cord, and frequency histograms were computed from multiunit (burst) activity during a 5-min control, an altered environment (10% O2) period, and a recovery period following hypoxic episodes. An hypoxic environment inhibited burst activity at 14 and 19 but not at 16 days.

A neurophysiological analysis of the effects of hypercapnia on the embryonic spinal cord.

Progressive hypercapnia in the normal chick embryo late in incubation (14-19 days) is temporally associated with a gradual decline in motor activity and the corresponding frequency of polyneuronal (burst) activity in the spinal cord. We have studied the possible correlation between the increasing hypercapnia and the declining frequency of burst activity seen during these later stages of incubation by systematic manipulation of CO2 levels. Burst frequency was seen to decrease as a result of a 5-min exposure to different carbon dioxide environments at all ages studied.