Osseous lipoma: CT appearance

Characteristic radiographic and computed-tomographic (CT) features of seven cases of osseous lipoma are reported: six with medullary and one with parosteal locations. Radiological diagnosis of this lesion is discussed, with emphasis on potential pitfalls in interpretation of CT scans. Although the presence of fat-equivalent density on scans is highly suggestive of osseous lipoma, comparable attenuation is documented in cases of chronic osteomyelitis and postnecrotic subchondral excavation.     

Ulcerative and granulomatous colitis in children. Comparison of double- and single-contrast studies

The authors reviewed 49 double-contrast and 27 single-contrast barium-enema examinations (BE) in 71 children with suspected inflammatory bowel disease. The diagnosis was proved in 41 patients, of whom 36 underwent proctoscopy and 5 had advanced disease which was treated surgically within 3 to 30 days after BE; the other 30 children served as controls. BE and proctoscopy were compared with regard to sensitivity (detection of disease) and accuracy (categorization as ulcerative or granulomatous colitis). Sensitivity was 93% for double-contrast and 82% for single-contrast BE. Both detected all cases of advanced disease; in early disease, double-contrast BE detected 91% of cases and single-contrast BE 70%. Colitis was correctly categorized as ulcerative or granulomatous in 93% with double-contrast BE and 86% with single-contrast BE. Specificity within the control group was 100% with both techniques. The authors conclude that both types of BE exhibit similar sensitivity in advanced disease, but the double-contrast technique is more accurate in detecting early disease.     

The infant hip: real-time US assessment of acetabular development

Until recently, radiography was the only available means of assessing acetabular development in infants with congenital hip dysplasia. Now that real-time ultrasonography (US) is successfully employed to determine hip position in infancy, it also offers an alternative method for evaluating acetabular development. In a review of 377 US studies of infant hips, the coronal-flexion images, which show a coronal section of the acetabulum with the hip in flexion, were measured to determine the percentage of the femoral head that was covered. Radiographs were measured to determine the acetabular index (angle). Acetabuli with indices exceeding the normal range for the subject's age showed head coverage of less than 33%. The 51 sonograms in this category were all associated with clinical abnormalities, whereas the 107 with coverage greater than 58% were associated with no clinical abnormalities and with consistently normal acetabular indices. The use of US in assessing acetabular development warrants continued investigation.     

Trimethoprim alone compared to co-trimoxazole in lower respiratory infections: pharmacokinetics and clinical effectiveness

24 patients, admitted to hospital with lower respiratory tract infection, were treated with either co-trimoxazole (800 mg sulphamethoxazole + 160 mg trimethoprim) or trimethoprim (200 mg) orally twice daily. All showed a clinical improvement and with one exception respiratory pathogens were eliminated. Pharmacokinetics in blood, sputum and saliva were studied in 11 patients taking trimethoprim and 9 taking co-trimoxazole. No sulphamethoxazole was detected in either the sputum or saliva. Trimethoprim was found in higher concentrations in the sputum than in the blood, although there were wide and significant variations in individual patient's sputum pharmacokinetic profiles. Trimethoprim penetrates into the sputum at therapeutic concentrations in patients with chronic respiratory infections.     

HTLV-I-induced lymphoma mimicking Hodgkin's disease. Diagnosis by polymerase chain reaction amplification of specific HTLV-I sequences in tumor DNA

A patient with a localized HTLV-I-associated lymphoproliferative disease that was misdiagnosed as Hodgkin's disease is presented. The patient's serum was negative for HTLV-I antibodies by enzyme-linked immunosorbent assay (ELISA), Western blot, and radioimmunoprecipitation. Tumor tissue DNA was negative for HTLV-I by Southern blotting but was positive for distinct HTLV-I sequences when subjected to DNA amplification using the polymerase chain reaction. We conclude that the clinical and pathologic diagnosis of HTLV-I-related lymphoma can be difficult and can be confused with Hodgkin's disease. Extremely sensitive molecular biological techniques may be required to establish a diagnosis of HTLV-I-induced lymphoma.     

Chronic exposure to tumor necrosis factor in vivo preferentially inhibits erythropoiesis in nude mice

The anemia of chronic disease (ACD) is associated with conditions in which macrophage activation occurs. Activated marrow macrophages suppress erythropoiesis in vitro and produce tumor necrosis factor (TNF). Therefore, we tested the effects of chronic in vivo exposure to TNF to determine if it was a candidate for a mediator of ACD. Nude mice were inoculated with Chinese hamster ovary (CHO) cells expressing the human TNF gene or with control cells containing the transfection vector alone. The TNF mice promptly became reticulocytopenic, and after 3 weeks their corrected reticulocytes were 2.6% +/- 0.7% as compared with 7.3% +/- 4% in control mice. The hematocrit at 3 weeks was 28.4% +/- 1.7% in TNF mice as compared with 46% +/- 0.8% in control mice. This anemia was also associated with low serum iron and normal iron stores and increased erythropoietin (Epo) levels. The TNF mice showed an absolute monocytosis with twice the number of circulating monocytes as control mice and had M-colony-stimulating factor (CSF) activity in their serum. The TNF mice also became mildly thrombocytopenic. Marrow CFU-E and BFU-E were profoundly decreased (1.2 +/- 0.2 x 10(3) v 8.6 +/- 0.2 x 10(4) CFU-E per femur, and 6.5 +/- 1 x 10(2) v 8.5 +/- 0.2 x 10(4) BFU-E per femur). Splenic CFU-E and BFU-E were similarly depressed. In contrast, marrow CFU-GM and CFU-GEMM were not affected. The residual BFU-E in TNF mice were relatively resistant to TNF as compared with control mice. These data demonstrate that TNF preferentially inhibits erythropoiesis in vivo and may be important in the pathogenesis of ACD.