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Biomedical subjects

B Levander

Publications and source records attributed to B Levander.

At least 19 recordsLinked to original sources
PubMed1988

Strength of implanted carbon fibers. Studies of the lumbar spine in goats.

The L3-4 supraspinous and interspinous ligaments in 10 goats were replaced with carbon fibers stabilized with silk-suture seizing. The implants were removed after 3 weeks in 5 animals and after 3 months in the other 5. The maximum traction strength of nonimplanted slings was 157 +/- 9 kg (M +/- SD). After implantation, the strength was reduced to 136 +/- 17 kg, and after 3 months to 107 +/- 9 kg. However, the maximum strength of the spinous processes was 71 +/- 19 kg, which was less than the strength of 3-month implants. We concluded that the carbon fiber sling stabilized with silk sutures could be used for replacement of the interspinous ligament.

Animals↗
PubMed1987

Respiratory gas pressures in the spine. Measurements in goats.

Normal values of pO2, pCO2, pH, and intraosseous pressure were measured in situ in the lumbar spine of goats. In the lumbar bodies and discs no difference existed between values found cranially and caudally. pO2 was lower and pCO2 higher in the nucleus pulposus than in the adjacent lumbar bodies. This emphasizes the nutritional route to the disc via the vertebral end plate. Intraosseous pressures in the cranial and caudal levels of the lumbar spine did not differ, and the pressures were the same as otherwise found in cancellous bone. These are the first combined in situ measurements of several basic metabolic parameters in the normal spine using recordings with continuous mass spectrometry. They may constitute a basis for further investigation of metabolism in the structures of the spine.

Animals↗
PubMed1981

Atlantoaxial instability in Marfan's syndrome. Diagnosis and treatment. A case report.

A case of Marfan's syndrome is described in which progressive neurological signs and symptoms were produced by flexion of the head. Radiological examinations revealed hypermotility between the atlas and axis, as well as compression of the medulla oblongata by the odontoid process on flexion, since low positioned cerebellar tonsils prevented dorsal shift of the oblongata. The signs and symptoms disappeared after occipitocervical internal transfixation.

Adult↗
PubMed1980

Atlantoaxial arthrography. A postmortem study.

The atlantoaxial joints of nine cadavers were examined with Amipaque. A lateral percutaneous approach was elaborated. Interarticular communications and pertinent anatomical features were analyzed.

Atlanto-Occipital Joint↗
PubMed1979

Angiographic findings in subdural hematoma correlated with CT attenuation values.

Twenty-eight subdural hematomas in 24 patients were examined by angiography and computed tomography (CT). The angiographic appearance of the hematomas was classified as either crescentic, lentiform, or transitional. The attenuation value of the hematomas was calculated from the CT scans. The mean attenuation of crescentic hematomas (13.8 EMI units--EU: 500 scale) was considerably lower than those of lentiform (21.7 EU) and transitional (19.8 EU) hematomas. The crescentic and transitional hematomas were either subacute or chronic, the chronic crescentic hematomas having an attenuation value at or around serum level. The lentiform hematomas were all more than 24 days old. The relatively high attenuation in chronic lentiform and transitional hematomas was probably caused by rebleeding, and the shape indicates enlargement of the hematomas after membrane formation has occurred. In the chronic, low attenuation crescentic hematomas, no recent bleed and no enlargement had occurred.

Adolescent↗
PubMed1978

Lumbo-omental shunt for drainage of cerebrospinal fluid in hydrocephalus.

A new cerebrospinal fluid (CSF) shunting procedure is presented. By transposing a pedicle graft of the greater omentum to the lumbar CSF compartment, the CSF absorption capacity of the omentum is utilized. The operation is applicable to the treatment of communicating hydrocephalus. The technical problems and physiological effects of the operation have been studied earlier in dogs. This paper presents the first case of an intended clinical series. The patient was studied for 18 months postoperatively by different examinations, including psychometric tests, cisternography, computer tomography, echo-ventriculography, and carotid angiography with measurement of the cerebral blood flow. A gradual improvement in his clinical state was registered after the operation.

Cerebrospinal Fluid Shunts↗
PubMed1978

Lumbo-omental shunt for drainage of cerebrospinal fluid--an experimental radionuclide study in dogs. II. Evaluation of transport routes from lumbar subarachnoid space to venous blood.

In a series of dogs, the transport routes of intrathecally administered 99Tcm-DTPA from an omental graft to the venous blood were studied by scintillation probes placed over the portal and external jugular veins and by blood samples from the inferior vena cava. It was found early in the course of investigation that a rich revascularization frequently occurred between the transplanted omentum and the surrounding muscles. In all dogs, the omental graft was divided, in its muscle tunnel about 5 cm outside the dural sac, 13--19 months after the implantation. Even after this a rapid transport to the venous system of radionuclide could be demonstrated. The revascularization of the graft was also studied morphologically in two dogs means of microangiography.

Animals↗
PubMed1978

Bulk flow of cerebrospinal fluid through a lumbo-omental pedicle graft in the dog.

Perfusion tests were performed in dogs with a pedicle graft of the greater omentum implanted in the lumbar subarachnoid space to measure its capacity to drain CSF. The CSF pressure was set at different levels in the range 0--50 mmHg and the outflow from a complete CSF space and then from the isolated dural sac was recorded in the same dog with an electronic drop recorder. It was shown that the omental graft could transport as much as 30% of the CSF normally carried by the physiological pathways. The spinal outflow in the controls was virtually non-existent. It is concluded that a bulk flow of CSF occurs through the graft. The results suggest that a lumbo-omental pedicle graft could possibly be used as a biological shunt in the treatment of hydrocephalus.

Animals↗
PubMed1978

Lumbo-omental shunt for drainage of cerebrospinal fluid--an experimental study in dogs. I. The transport of cerebrospinal fluid from the lumbar subarachnoid space, studied by 169Yb-DTPA and a gamma camera.

Studies using an experimental cerebrospinal fluid (CSF) shunting procedure are presented. By transposing a pedicle graft of the greater omentum to the lumbar subarachnoid space, the CSF absorption of the omentum can be utilized. Monitoring the absorption of intrathecally administration of 169Yb-DTPA by gamma camera sequential pictures 1 to 17 months after the shunt procedure, a rapid transport of radionuclide from the lumbo-omental shunt to the systemic venous blood was demonstrated.

Animals↗
PubMed1978

Computer tomography of the brain and spectrophotometry of the CSF in cerebral concussion and contusion.

Computer tomography (CT) and spectrophotometry of CSF were performed in 30 patients with the clinical diagnosis of cerebral concussion or contusion. The patients with concussion all had normal CT-findings. Spectrophotometry of CSF was sometimes positive for cerebral contusion with normal CT-findings, but the two methods were complementary so that the extent of the lesion was determined by CT and spectrophotometry of CSF indicated the cause.

Brain Concussion↗
PubMed1977

Variation with time of the attenuation values of intracranial hematomas.

Fourteen cases of subdural, epidural, and intracerebral hematoma, in which the time of the trauma or bleeding was known, were selected. Attenuation of samples taken at surgery showed good correlation with attenuation values determined by computed tomography (CT). The decrease in the attenuation of the hematoma from the time of trauma or bleeding was studied.

Brain↗