Search PubMed⌕ Search

Biomedical subjects

J L Story

Publications and source records attributed to J L Story.

At least 37 records · Page 2Linked to original sources
PubMed1980

Stepping by chronic spinal cats.

We investigated the consequences of spinal cord transection in adult cat. All became capable of stepping upon a treadmill. Two of six animals stepped in the first postoperative testing session, 1 week after surgery. It took up to 6 weeks for the others to start stepping. None of the cats became capable of hindquarter support within 2 months after surgery. There was permanent loss of fore-hindlimb coordination and increased variability in the duration of each step cycle and its components. Coordination between the hindlimbs was also impaired, as signaled by increased variability in the time between foot contacts with the belt. These changes may be due to the loss of timing signals coming down from supraspinal levels to the segmental step generators or - alternatively - to decreased excitability of segmental motoneurons leading to less precise execution of stepping commands from the hypothetical pattern generators.

Animals↗
PubMed1980

Intermittent appearance of a ruptured cerebral aneurysm on sequential angiograms. Case report.

The change in size of a ruptured anterior cerebral artery aneurysm was recorded in a series of angiograms. The aneurysm did not appear on the initial angiogram, but was seen on the second study. Incomplete filling was seen on the third angiogram, and the aneurysm appeared to have thrombosed on the fourth angiogram. On the fifth angiogram, done 5 weeks after the first, the aneurysm filled completely. It was subsequently clipped.

Cerebral Angiography↗
PubMed1979

Subclavian steal syndrome. Part 1: Proximal vertebral to common carotid artery transposition in three patients, and historical review.

Three patients with central nervous system symptoms due to subclavian steal syndrome were treated with proximal vertebral to common carotid artery transposition. Neurological symptoms were relieved or improved in all three, with no decrease in blood pressure or pulse in the ipsilateral upper extremity. The colorful history of this syndrome is reviewed, and the various surgical approaches to its treatment are discussed. Although the literature suggests that the commonly used carotid to subclavian artery bypass graft and other similar extrathoracic procedures are generally safe and effective for relief of symptoms of the steal, there is also evidence that these bypasses may fail to restore antegrade flow in the vertebral artery, and, in fact, may steal from the carotid artery. Thus, the blood flow provided to the brain by these procedure may be hardly more than that provided by vertebral artery ligation, whereas the principal effect is to restore blood flow into the upper extremity. Vertebral artery ligation alone has been used in 20 patients, with neurological improvement in all cases and production of persistent intermittent brachial claudication in only one. These considerations and our patient experience suggest that a relatively simple operation, proximal vertebral to common carotid artery transposition, which emphasizes restoration of flow to the brain rather than to the upper extremity, may be preferable for most patients with neurological symptoms of subclavian steal syndrome.

Adult↗
PubMed1979

Subclavian steal syndrome. Part 2: Intraoperative vertebral artery blood flow measurement.

Intraoperative vertebral artery blood flow was measured in two patients with symptomatic subclavian steal syndrome, before and after proximal end-to-side vertebral to common carotid artery transposition. This confirmed retrograde flow in the vertebral artery before transposition, and antegrade flow after transposition. The measured flow rates were compared to values in other series involving different operative procedures for correction of symptomatic subclavian steal. The greatest mean antegrade flow rates in the vertebral artery were restored by proximal end-to-side vertebral to common carotid artery transposition.

Collateral Circulation↗
PubMed1976

Chronic measurement of epidural pressure with an induction-powered oscillator transducer.

An induction-powered oscillator transducer (IPOT) was designed for the chronic measurement of epidural pressure. The transducer was completely implantable so all pressure measurements were made through the intact skin. The IPOT had a linear pressure range from -50 to +200 cm H2O, was sensitive to 1 mm H2O and had a zero drift of less than 1 mm H2O/day under full load. Zero drift was minimized by using a hermetically-sealed metal bellows transducing element which was chemically treated to prevent corrosion and creep. The correlation between epidural pressure and intraventricular pressure was determined during the first 24 hours after implantation in six dogs. Epidural pressure was found to be a linear function of intraventricular fluid pressure. Epidural pressure and intraventricular pressure were essential equal provided the epidural wedge pressure was minimized by proper insertion of the transducer. The correlation between epidural pressure and intraventricular pressure was determined after chronic implantation in five dogs. Epidural pressure was a linear function of intraventricular pressure in the chronically implanted dogs, but epidural pressure was not equal to intraventricular pressure. After chronic implantation, the epidural pressure transducer was not responsive to changes in intraventricular pressure because of mechanical changes in the dura. The dura became stiff and non-compliant. Maximum correlation between epidural pressure and intraventricular fluid pressure in chronic implantations will depend on judicious material selection and mechanical design at the transducer-dura interface.

Animals↗