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Biomedical subjects

G Ritter

Publications and source records attributed to G Ritter.

269 records · Page 15Linked to original sources
PubMedDate not supplied

Electrophoretic analysis of the novel antigen for the gastrointestinal-specific monoclonal antibody, A33.

The murine monoclonal antibody A33 (mAbA33) recognises a human cell membrane-associated antigen selectively expressed in epithelial cells of the lower gastrointestinal tract and > 90% of colonic cancers, but is not detected in a wide range of other normal tissues by immunohistochemical analysis. In phase I/II clinical triasl, mAbA33 has been shown to target advanced colon cancers and the humanized version is currently being evaluated in therapy studies. Although the mAbA33 has been well characterised by immunohistochemical and clinical studies, until recently, the target antigen has remained poorly defined. This was largely attributable to the antigenic determinant recognised by mAbA33 being dependent on the native spatial conformation of the A33 antigen which impeded its identification by conventional two-dimensional electrophoresis (2-DE) and immunoblot analysis. We have developed an immunoblot method, based on nonreducing/non-urea precast 2-DE gels, that has facilitated the purification of the detergent (0.3% Triton X-100) solubilised A33 antigen from the human colon cancer cell lines LIM1215 and SW1222. Under these 2-DE conditions, the A33 antigen electrophoreses with an apparent M(r) approximately 41000 and pI 5.0-6.0. Attempts to isolate the A33 antigen from 2-DE gels for direct structural analysis were unsuccessful, due to its co-electrophoresis with actin and cytokeratin proteins. However, using Western blot and biosensor detection the A33 antigen has been purified chromatographically and N-terminal sequence analysis was possible. Using polyclonal antibodies raised against a synthetic peptide corresponding to the N-terminal region of the A33 antigen we have used Western blot analysis to localise the molecule in our master 2-DE protein database for normal human colon crypts and several colon carcinoma cell lines (URL address: http:(/)/www.ludwig.edu.au). Under reducing 2-DE conditions, the A33 antigen electrophoresis as 6 differentially charged isoforms (pI 4.6-4.8) with a single molecular weight species at M(r) approximately 55000.

3T3 Cells↗
PubMedDate not supplied

[Aseptic bone necroses as a late complication following successful treatment of leukemias and severe aplastic anemia].

Aseptic bone necrosis is a well known complication after corticosteroid treatment in adults and several hundred cases have been reported. Alterations in fat metabolism with vascular occlusion due to fat embolization, as well as microtraumata and osteoporosis are discussed as etiologic factors. In contrast, aseptic bone necrosis in relation to corticosteroid treatment is rare in children and adolescents. We therefore report 3 patients, aged from 10 to 18 years, suffering from severe aplastic anemia, meningeal relapse after acute lymphocytic leukemia and acute myelocytic leukemia respectively, who developed aseptic bone necrosis 6, 11, and 20 months following the onset of corticoid therapy. The patients survive from 28+ to 50+ months after diagnosis of their initial hematologic disease, as it can be expected today for increasing numbers of patients. We therefore believe, that aseptic bone necrosis may represent a serious therapy related complication and suggest that, diagnostic examination in patients with suspicious complaints of the hip, shoulder or knee should also exclude the possibility of a bone necrosis after leucemic relapse has been ruled out. Since radiological changes only develop several weeks to months after the onset of the clinical symptoms and because of the disabling consequences for patients, misdiagnosed at the beginning, a 99 technetium bone scan should be done as early as possible. Corticosteroids, despite their serious side effects are still being considered as a important part of hematologic therapy and are not being omitted in the near future, so that the earliest possible diagnosis of bone necrosis will remain of great importance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMedDate not supplied

[Intramedullary bundle nailing for stabilization of pathologic humerus fractures in malignant tumors].

Pathological fractures of the humerus are mostly due to skeletal metastases or to malignant bone tumours. In most of the cases fracture stabilization as a palliative measurement is the only possible therapy. Our own collective during 1980 through 1987 includes 77 pathological fractures of the long bones, 23 of them located in the humerus. In eight of 15 fractures of the humeral shaft intramedullary nailing was performed, in two cases bone cement was used in addition.

Bone Neoplasms↗
PubMedDate not supplied

[Post-traumatic femur head necrosis following trochanter fracture].

Avascular necrosis of the femoral head after fractures of the major or minor trochanter have not been published yet. We are able to present such a casereport of a 12 years old girl. We discuss the different reasons for femoral head necrosis by this case.

Adolescent↗
PubMedDate not supplied

[Perthes' disease in scintigraphy - early diagnosis, course and therapeutic consequences].

A four year study on radionuclide imaging in Perthes's disease is reported. The results reveal that radionuclide imaging facilitates the earliest diagnosis possible as well as the differentiation against other affections of the hip. In eleven cases (diagnoses ascertained by X-ray follow up or biopsy) the duration of the course of Perthes' disease was shortened and the ultimate outcome was improved because of the early onset of therapy. Follow up examinations with radionuclide imaging and quantification of uptake reveal the extent of revascularisation of the necrosis of the femoral head and the epiphyseal plate at any point in time during the course of the disease. This leads to prognostic and therapeutic consequences, particularly in view of expected head at risk signs in the development of Perthes' disease.

Adolescent↗
PubMedDate not supplied

A comparison of predictive outcomes of APACHE II and SAPS II in a surgical intensive care unit.

The Acute Physiologic Score and Chronic Health Evaluation (APACHE) II and the Simplified Acute Physiologic Scale (SAPS) II are two of the more commonly employed predictors of outcome and performance in the intensive care unit setting. However, controversy persists about whether the scores generated by these systems have similar predictive value. This study compared the predicted mortalities derived from APACHE II and SAPS II and contrasted them to the actual mortality in a surgical intensive care unit (SICU). Data for 1665 patients admitted to the SICU between July 1994 and August 1997 were entered into an SICU computerized database. From recorded demographic, hemodynamic, and laboratory data, APACHE II and SAPS II scores were obtained with corresponding predicted mortalities. Patients were stratified by age into categories of less than and greater than 65 years old. Predicted mortalities by APACHE II and SAPS II were compared for each group. An additional analysis included a comparison of survivors and nonsurvivors. There was no significant difference in predicted mortality between APACHE II and SAPS II in any of the groups. Actual mortality was 30 of 486 (6.2%) in patients less than 65 years of age and 73 of 1179 (6.2%) in patients 65 years of age or greater. The APACHE II and SAPS II predicted mortalities (mean +/- SD) for patients less than 65 years of age were 10.5% +/- 10.6% and 10.9% +/- 13.3%, respectively (P > .05). The APACHE II and SAPS II predicted mortalities in patients 65 years of age or greater were 19.1% +/- 17.8% and 18.7% +/- 21.0%, respectively (P > .05). Similarly, when patients were stratified by survival status, no significant difference was present between groups. However, in individual patients, a difference between APACHE II and SAPS II scores was often present. We conclude that although disparities between APACHE II and SAPS II predicted mortalities in individual patients may be significant, APACHE II and SAPS II have similar predictive value in a large SICU patient population. However, both APACHE II and SAPS II systems overestimate mortality in SICU patients. Based on our results, we conclude that either system can be used to measure quality of care in the SICU; however, neither system can be reliably applied to a single patient.

APACHE↗
PubMedDate not supplied

Growth in prescription drug spending among insured elders.

We examine growth in prescription drug use and spending in a well-insured elderly population in 1997 and 2000. We describe the high-cost segment of this population, identifying how it differs from the rest of the elderly regarding use and types of medications, and how stable this group is over time. Drug spending by the insured elderly rose more than 18 percent annually between 1997 and 2000. High-cost elders use more brand-name drugs, treat more conditions, and use more medications per condition. Once an insured elder becomes a high-cost user of prescription drugs, that person is likely to remain so. Our study suggests that a growing population of elderly is using many medications and may require considerable drug management.

Age Factors↗