Jennifer A Smith — Page 2

PubMed2003

Block in development at the pre-B-II to immature B cell stage in mice without Ig kappa and Ig lambda light chain.

Silencing individual C (constant region) lambda genes in a kappa(-/-) background reduces mature B cell levels, and L chain-deficient (lambda(-/-)kappa(-/-)) mice attain a complete block in B cell development at the stage when L chain rearrangement, resulting in surface IgM expression, should be completed. L chain deficiency prevents B cell receptor association, and L chain function cannot be substituted (e.g., by surrogate L chain). Nevertheless, precursor cell levels, controlled by developmental progression and checkpoint apoptosis, are maintained, and B cell development in the bone marrow is fully retained up to the immature stage. L chain deficiency allows H chain retention in the cytoplasm, but prevents H chain release from the cell, and as a result secondary lymphoid organs are B cell depleted while T cell levels remain normal.

Animals↗

PubMed2002

Lead-in phase to randomized trial of motexafin gadolinium and whole-brain radiation for patients with brain metastases: centralized assessment of magnetic resonance imaging, neurocognitive, and neurologic end points.

PURPOSE: Motexafin gadolinium is a redox mediator that selectively targets tumor cells, is detectable by magnetic resonance imaging (MRI), and enhances the effect of radiation therapy. This lead-in phase to a randomized trial served to evaluate radiologic, neurocognitive, and neurologic progression end points and to evaluate the safety and radiologic response of motexafin gadolinium administered concurrently with 30 Gy in 10-fraction whole-brain radiation therapy for the treatment of brain metastases. PATIENTS AND METHODS: Motexafin gadolinium (5.0 mg/kg/d for 10 days) was administered before each radiation treatment in this prospective international trial. Patients were evaluated by MRI, neurologic examinations, and neurocognitive tests. Prospective criteria and centralized review procedures were established for radiologic, neurocognitive, and neurologic progression end points. RESULTS: Twenty-five patients with brain metastases from lung (52%) and breast (24%) cancer, recursive partitioning analysis class 2 (96%), and an average of 11 brain metastases were enrolled. Neurocognitive function was highly impaired at presentation. Motexafin gadolinium was well tolerated. Freedom from neurologic progression was 77% at 1 year. Median survival was 5.0 months. In 29% of patients, the cause of death was brain metastasis progression. The radiologic response rate was 68%. Motexafin gadolinium's tumor selectivity was established with MRI. CONCLUSION: (1) Centralized neurologic progression scoring that incorporated neurocognitive tests was implemented successfully. (2) Motexafin gadolinium was well tolerated. (3) Local control, measured by radiologic response rate, neurologic progression, and death caused by progression of brain metastasis, seemed to be improved compared with historical results. A randomized phase III trial using these methods for evaluation of efficacy has just been completed.

Adult↗