RNA virus associated antigen in human placenta.

Using indirect immunofluorescence microscopy, it was demonstrated that human cytotrophoblast of six to ten weeks gestation contains mouse mammary tumor virus associated antigen. This antigen appeared predominantly in the periphery of the cells.

The Ask-Upmark kidney in a premature infant.

A premature infant with segmental hypoplasia of one kidney is reported. Since 1929 when Ask-Upmark first reported this renal anomaly and its association with hypertension, the nature of the lesion has remained in doubt. The question whether it is acquired post-natally or whether it is a developmental mal-formation has not been resolved. The case which we now report clearly documents the prenatal development of the lesion as well as its association with arrested nephrogenesis and the presence of abnormal vasculature. The cause of these changes is not clear, but it is suggested that ureteral reflux was present.

Pheochromocytoma with angiomatous features. A case report and ultrastructural study.

A functional pheochromocytoma of the adrenal gland but with an angiomatous histologic pattern was studied by light and electron microscopy. Although this tumor had typical clinical and gross anatomic features, its light microscopic appearance was unique and, to our knowledge, has not been previously described. Fine structural study provided insight into the intracellular pathways of catecholamine granule formation.

Rat polyvinyl sponge model for the study of infections: initial investigations.

Polyvinyl sponges were implanted subcutaneously on both sides of young female rats. One sponge was infected with 10(8) of either Escherichia coli K-12 F-, Staphylococcus aureus ATCC 25923, or Pseudomonas aeruginosa CDC 7725. P. aeruginosa remained at the inoculum level and S. aureus declined by 1 log, whereas E. coli was reduced 1,000-fold. Only P. aeruginosa was recovered from the blood in 36% of the animals in 24 h and in 20% of the rats in 48 h. The nutrient potential of rat inflammatory fluid was compared to nutrient broth by growth of each bacterium in untreated and heat-inactivated sponge fluids and Trypticase soy broth.

Rat polyvinyl sponge model for the study of infections: host factors and microbial proliferation.

Female rats were treated with several administration regimens of methylprednisolone, cobra venom anti-complementary factor, and cyclophosphamide in conjunction with polyvinyl sponge implantations. The effect of these drugs on host factors active against bacteria was evaluated with Staphylococcus aureus ATCC 25933, Escherichia coli K-12, and Pseudomonas aeruginosa CDC 7725. One of two implants in each animal was infected with 10(8) of one of the three bacteria, and bacterial and granulocyte content was determined in the infected and control sponges after 48 h. The single large dose of methylprednisolone decreased staphylococcal and E. coli clearance while promoting dissemination of P. aeruginosa. A low chronic dose of the steroid inhibited E. coli chemotaxis only. A higher dose of the steroid administered chronically interfered markedly with S. aureus and E. coli curtailment by the host while leading to enhanced dissemination of P. aeruginosa, accompanied by a precipitous decline in granulocytes. Results with cobra factor resembled the higher chronic dose of steroid enhancing, especially the dissemination of the pseudomonad and its anti-granulocytic propensity. Cyclophosphamide depression of granulocytes revealed the rat's ability to curtail the proliferation of particular S. aureus and E.coli strains even in the absence of leukocytes. This treatment resulted in the rapid spread of P. aeruginosa, leading to the death of some experimental animals. These experiments underline the versatility of this animal model in the study of host and microbial factors influential in infectious disease.

Primary osteomyelitis due to an anaerobic microorganism.

Primary osteomyelitis in a teen-aged boy that mimicked Ewing's tumor radiologically showed small Gram-negative rods on the original smear. The organism isolated was an obligately anaerobic bacterium, finally identified as Clostridium sphenoides. This finding underlines the need for microbiologic analysis of orthopedic lesions.