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Biomedical subjects

A B Weiss

Publications and source records attributed to A B Weiss.

At least 37 records · Page 2Linked to original sources
PubMed1978

Developmental lumbar spinal stenosis. Pathology and surgical treatment.

The purpose of this presentation is to outline the extent of surgical resection necessary for complete decompression of the neural elements in spinal stenosis and to introduce a system for the evaluation of disability in patients with spinal stenosis. Sixteen patients with the confirmed diagnosis of lumbar spinal stenosis were evaluated by the system. Ten cases were treated surgically. Indications for operative treatment were 1) intolerable pain in average daily living, 2) progressively worsening or significant degree of motor weakness, and 3) sphincter dysfunction. Satisfactory results from operative treatment were expected only after adequate and thorough decompression. The extent of surgical decompression was determined by clinical evaluation, myelographic examination, and by the type of disease process exhibited. The most common cause of unsatisfactory results was inadequate decompression of spinal contents. The extent of adequate decompression is described according to three different variations of pathologic anatomy of spinal stenosis: a) concentric contraction of the spinal canal, b) sagittal flattening of the spinal canal, and c) stenosis caused by anomalous articular process(es). No excellent results were obtained even after thorough and adequate decompression of spinal contents.

Humans↗
PubMed1978

Tumor immunology of experimental osteosarcoma.

A spontaneous AP positive C3H murine OS was used to determine the effects of various treatment modalities. AP served as a useful circulating biomarker of the in vivo tumor growth. In animals whose tumor was amputated, the elevation of the marker indicated the presence of pulmonary metastases. It was used to establish the time of recurrence after a partially effective chemotherapy or combination modality. In this model, when the neoplasm was surgically excised at 10 days posttransplantation, 70--80% of the mice showed presence of lung metastases. Specific immunotherapy with irradiated tumor cells did not alter the course of the disease. Passively transferred immune allogeneic cells to tumor bearing mice at an effector to target cell ratio of 1:1 in vivo were ineffective. The murine OS model is extremely useful to plan and institute different combinations of treatment modalities and optimize the conditions for an effective treatment in a relatively short time.

Alkaline Phosphatase↗
PubMed1978

Osteosarcoma: a review of 50 patients treated at the University of Alabama in Birmingham Medical Center between 1944 and 1975.

Only 12% of 50 patients lived 5 years or longer. Those who survived the longest were those with the tumor in the distal part of the lower extremity, with a well differentiated or chondroblastic tumor, or those who underwent radical surgery. Patients treated with surgery and chemotherapy lived about 1.5 months longer than those treated with sugery alone and about 1.2 months longer than those who had radiation included in the therapy. For a patient with a diagnosis of osteosarcoma, the prognosis was to be grave, no matter which methods of treatment were used.

Adolescent↗
PubMed1977

Posterior fracture dislocation of the hip.

We have reviewed 46 posterior fracture dislocations of the hip treated at the University of Alabama in Birmingham Hospitals and the Birmingham Veterans Administration Hospital from 1963 to 1973. Of the 13 injuries which were followed up for at least one year, there were two good, five fair, and six poor clinical results. One instance of aseptic necrosis was documented. There was no obvious correlation between fracture type or treatment and clinical result in this preliminary series.

Adolescent↗
PubMed1977

Medial displacement osteotomy for unstable intertrochanteric femoral fractures.

The charts and roentgenograms of 86 consecutive patients treated by medial displacement osteotomy between 1970 and 1974 were reviewed. All patients had unstable four-fragment intertrochanteric fractures and were treated by the residents and attending staff of the hospitals served by the University of Alabama Medical Center. Thirty patients had sufficient follow-up to be included in the preliminary retrospective study. There were complications of fixation in 11 patients (37%) and one superficial wound infection (3%). The most significant factors associated with complications of fixation were (1) placement of the nail in a superior and anterior position in the femoral neck and head, and (2) advanced osteoporosis. No correlation was noted with the distance of the tip of the nail from the femoral articular cartilage.

Adult↗
PubMed1977

Supramalleolar fracture of the ankle (Malgaigne's fracture).

A retrospective study of 26 cases of supramalleolar fracture is presented. Types II and III were most common. All but the one had accompanying fibular fracture. The incidence of open fracture was 41.7% (10/24). The most common mechanism of injury was a high energy impacting force in the direction of axial compression. The supramalleolar fracture was subgrouped into four types. Twenty patients were treated by closed reduction and cast immobilization for an average of five months, six by open reduction and internal fixation, and two by skeletal traction in the early course of treatment. Of the 21 patients who were followed for an average of 33 months, only seven were found to have satisfactory results and were free from complications. Fourteen patients were found to have complications.

Adult↗
PubMed1976

Biocompatibility studies on surgical-grade titanium-, cobalt-, and iron-base alloys.

An animal model system for the investigation of the influence of in vivo-produced metallic corrosion products upon tissues has been developed. Externally applied electrical stimulation produces the corrosion over a short period of time, and a poststimulation period is allowed for tissue stabilization. Tissue reaction adjacent to the metallic alloys shows fibrous tissue capsules and metallic corrosion product contamination. These preliminary studies show that this animal model and methodology may provide a technique for investigating long-term tissue biomaterial interactions and the influence of iron (316L), cobalt (Vitallium), and titanium (Tivanium) alloy corrosion products upon the susceptibility of tissues to various biocompatibility challenges.

Animals↗
PubMed1976

Monitoring of murine osteosarcoma by serial alkaline phosphatase determinations.

To establish that alkaline phosphatase (AP) was released by osteosarcoma cells, we measured this enzyme in C3H/HeJ mice with im-implanted osteosarcoma and in in vitro cultures of neoplastic cells subjected to short-term incubation. We found that 10(5) osteosarcoma cells synthesized a significant amount of AP in vitro in 30 minutes at 37 degrees C. A good correlation existed between pulmonary metastatic tumors and the AP values. Serum AP measurements indicated approximate sizes of disseminated and localized tumors, but could not monitor early localized tumors.

Alkaline Phosphatase↗
PubMed1976

Cast bracing for femoral shaft fractures.

The femoral cast-brace offers a new method of treatment for femoral shaft fractures. The cast-brace is especially well suited to fractures below the isthmus, although it can be used to treat those more proximal by giving special attention to detail. The method allows early knee motion without prolonged bed rest. Patients who should not be operated on for any medical reason or whose fracture is not amenable to surgery may be treated with the cast-brace. A series of patients with simple and complicated problems that have been treated with the cast-brace is presented. Comparisons between femoral cast-bracing, intramedullary nailing, and traction treatment are made.

Adolescent↗
PubMed1969

Further observations on overt "mediating" behavior and the discrimination of time.

When the lever-pressing behavior of five rats was maintained by a DRL schedule (reinforcement was scheduled only when a specified waiting time between successive responses was exceeded), collateral behavior developed that apparently served a mediating function. In two cases this behavior did not arise until the experimental environment included pieces of wood that the rats started to nibble. When collateral behavior first appeared, it was always accompanied by an increase in responses spaced far enough apart to earn reinforcement. If collateral behavior was prevented, the number of reinforced responses always decreased. Extinction of lever pressing extinguished the collateral behavior. Adding a limited-hold contingency to the schedule did not extinguish collateral behavior. It appears that the rat can better space its responses appropriately when concurrently performing some overt collateral activity. The amount of this activity apparently comes to serve as a discriminative stimulus. To assume the existence of internal events that serve as discriminative stimuli in temporal discriminations is, at least under some circumstances, unnecessary.

Animals↗
PubMedDate not supplied

Isolated congenital cervical block vertebrae below the axis with neurological symptoms.

A reviews of 13 cases of symptomatic isolated congenital cervical fusion (block vertebrae) below the C2 level is presented. Ten cases were collected from a review of the English literature and three new cases were added. All 13 patients presented neurologic symptoms of radiculopathy and/or myelopathy with either no history of trauma or only minor trauma. Pathogenesis of symptoms is due to degenerative arthritis of the adjacent mobile segments, spinal stenosis, and subluxation of the adjacent mobile segments. The significance of coexisting spinal stenosis and segmental instability is emphasized and is related to the symptoms and treatment of the condition. Symptomatic patients can be treated satisfactorily with adequate decompressive laminectomy and fusion of the unstable segments.

Adult↗
PubMedDate not supplied

Medial collateral ligament replacement with a partially absorbable tissue scaffold.

The medial collateral ligaments and medial capsular structures of canines were resected and replaced with a carbon fiber-polylactic acid polymer tissue scaffold or allowed simply to "scar-in." After 4, 8, 12, and 26 weeks in vivo, the stability of the knees was quantitatively evaluated and the mechanical properties of the regrown structures determined. Histological sections of the regrown structures were examined after 26 weeks in vivo. At all time periods, the knees receiving tissue scaffold ligaments were significantly more stable than those knees allowed to stabilize with scar tissue. Initial strength, rapid ingrowth, and benign tissue reaction suggest this new composite material may be useful in the treatment of joint instability.

Animals↗