Patellofemoral joint: kinematic MR imaging to assess tracking abnormalities

The patellofemoral joint was imaged with magnetic resonance (MR) in the axial plane while the knee was positioned from 0 degrees to 32 degrees of flexion (nine positions). These multiple sequential images obtained within the early phases of flexion of the knee were viewed in a "cine-loop" format, producing a kinematic study that clearly demonstrated the relationship of the patella to the trochlear groove. Four healthy subjects and one patient with known bilateral subluxing patellae were studied. The preliminary results suggest that kinematic MR imaging of the patellofemoral joint is potentially useful for the evaluation of patellar tracking abnormalities.     

Influence of iron on in vivo proliferation and lethality of L1210 cells

The ability of iron to stimulate the growth of L1210 cells both in DBA-2 mice and in cell culture is evaluated. Although in vitro stimulation is absent, in vivo studies clearly indicate higher numbers of tumor cells in the presence of supplemental iron. When mice were given iron i.p., at levels comparable to clinical doses for humans (24 mg/kg body weight), the tumor load recovered from their peritoneum was substantially greater than from controls without iron supplements. Furthermore, at higher levels of supplemental iron (250 mg Fe/kg body weight), the pretreated animals inoculated with L1210 cells died in 9.7 d whereas controls died in 12.2 d (i.e., 25% faster). As expected, the lower iron dose (24 mg/kg) also resulted in shorter life spans, although the effects were less striking. It is the belief of these authors that these data support the opinion that "anemia of chronic disease" associated with leukemia and possibly other malignancies may represent a host defense mechanism as has been postulated by others (1, 8).     

Marrow regeneration after mechanical depletion

The origin of marrow regeneration after mechanical depletion was reinvestigated in mouse chimeras. The results were compatible with the local origin of stem cells from remnants of incompletely removed marrow, but not with their origin from a common precursor of both bone and hemopoietic cell lines. In transplanted femurs depleted by a modified technique of in vivo evacuation of marrow, hemopoietic regeneration failed to occur. The presence of hemopoietic stem cells in the Haversian canals was thus excluded. The demonstration of ample hemopoiesis with minimal bone formation in nondepleted controls in which bone marrow initially became necrotic provided new evidence that osteogenesis was not a prerequisite of hemopoietic regeneration.     

Severe malabsorption in autoimmune polyendocrinopathy-candidosis-ectodermal dystrophy syndrome successfully treated with immunosuppression

A 15 year old boy with autoimmune polyendocrinopathy-candidosis-ectodermal dystrophy syndrome suffered recurrent episodes of severe intractable diarrhoea, steatorrhoea, and hypocalcaemia. The only treatment modality, which controlled the malabsorption syndrome, was immunosuppression with intravenous high dose methylprednisolone and oral methotrexate maintenance therapy.