Shah-Waardenburg syndrome and Dandy-Walker malformation: an autopsy report.

Autopsy reports of individuals with Shah-Waardenburg syndrome are rare, and to the best of our knowledge, have never been reported in association with Dandy-Walker malformation. This report documents the autopsy findings of a 2.5-year-old boy with Shah-Waardenburg syndrome (Type IV Waardenburg syndrome) and a Dandy-Walker malformation. The patient had a past medical history of congenital deafness, skin and hair pigmentary disturbances, Hirschsprun disease and hydrocephalus. At autopsy, multiple patches of dermal and hair hypopigmentation were observed over the face, trunk, eyelashes and eyebrows. The brain had a small, underdeveloped anterior cerebellar vermis, bilateral atrophic cerebelli, a markedly dilated ventricular system and a large incomplete midline cerebellar cyst. The entire colon and much of the small bowel had been previously excised secondary to the Hirschsprung disease. This case expands the spectrum of pathologic findings in Shah-Waardenburg syndrome to include the Dandy-Walker malformation.

Plasmodium chabaudi chabaudi: B-1 cell expansion correlates with semiresistance in BALB/cJ mice.

The largest obstacle impeding the development of an effective malaria vaccine is the incomplete understanding of how the immune response is regulated during infection. B-1a cells, a poorly understood subcategory of B lymphocytes, produce nonpathologic autoantibodies of low affinity which have been shown to have distinct immunoregulatory capabilities. What the exact activity of B-1a cells are during the course of malaria has yet to be determined. By use of flow cytometry, it was observed that B-1a cells significantly expand by day 3 postinfection in the spleen and peritoneum of Plasmodium chabaudi chabaudi semiresistant BALB/cJ mice, but not until day 8 postinfection in the spleen of P. chabaudi chabaudi fully susceptible BALB/cByJ mice. The activation of B-1a cells was also demonstrated by the measurement of natural autoantibody IgM production from the serum and cultured peritoneal B-1a cells. Infected semiresistant BALB/cJ mice generated higher levels of anti-ssDNA IgM antibodies than infected fully susceptible BALB/cByJ mice. The preliminary data presented here suggest a possible roll of B-1 cells in contributing to the successful survival of murine malarial infection.

Tumor necrosis factor alpha acts as an autocrine second signal with gamma interferon to induce nitric oxide in group B streptococcus-treated macrophages.

Nitric oxide production by mouse macrophages treated with group B streptococci and gamma interferon was inhibited by cytochalasin B or by antibody neutralization of macrophage-derived tumor necrosis factor alpha. Phagocytosis-induced tumor necrosis factor alpha is responsible for group B streptococcus-induced nitric oxide production in interferon-treated macrophages.