Stimulation of human monocytes by anti-CD3 monoclonal antibody: Induction of inflammatory mediator release via immobilization of Fc receptor by adsorbed immunoglobulin and T-lymphocytes

Human monocytes released superoxide anion, prostaglandin E₂, leukotriene B₄, IL-1, and TNF when exposed to plastic surfaces coated with murine anti-CD3 monoclonal antibody, OKT 3. Stimulation of mediator release by OKT 3 was dependent on the amount of antibody immobilized onto wells of plastic tissue culture plates. Soluble antibody or antibody adsorbed to monocytes and reacted with an aggregating (cross-linking) second antibody failed to induce mediator release. Monocytes armed with OKT 3 formed rosettes with T cells in a fashion indistinguishable from that seen between monocytes and T cells sensitized with OKT 3. Monocytes with adsorbed OKT 3 antibodies released IL-1 and TNF- when exposed to unsensitized T cells, although increased superoxide release could not be detected. OKT 4a, a murine IgG_2a antibody that reacts with a different T cell epitope (CD4), failed to induce cytokine release from monocytes when cross-linked by T cells or a CD4+ T cell line, even in the presence of IL-2 or IFN-. These data indicate that certain antibodies bound to Fc receptors (FcR) of monocytes may trigger monocyte function when reacting with cells bearing the appropriate target antigens. FcR-mediated signaling resulting in mediator release may be involved in initiating or regulating the immune response. Furthermore, systemically administered monoclonal antibodies may induce inflammatory responses and their attendant symptomatologies via their interaction with FcR-bearing inflammatory cells.     

Syndrome of partial aniridia, cerebellar ataxia, and mental retardation--Gillespie syndrome

Here we describe a 5-year-old girl with Gillespie syndrome of cerebellar ataxia, partial aniridia, and mental retardation. The Gillespie syndrome probably is an autosomal recessive trait.     

Amanita virosa induced toxic hepatitis: report of three cases

We report here three cases of Amanita virosa induced toxic hepatitis. Two of the three cases recovered but the other died 10 days after mushroom ingestion. Since the mortality of Amanita mushroom induced toxic hepatitis is very high, prompt diagnosis and aggressive therapeutic measures should be initiated as soon as possible. Our cases showed that the initial serum aminotransferase levels might not predict the clinical outcome of the patient, but that the prothrombin time (PT) seemed to be a more useful prognostic marker. Close monitoring of aminotransferase levels and PT as well as appropriate therapy are recommended. All three cases showed signs of proteinuria and we were able to characterize mixed tubular and glomerular type proteinuria at 3 or 4 days after ingestion in two cases. Among the previously reported Korean cases of suspected Amanita induced toxic hepatitis, most species could not be identified except for four cases of Amanita virosa. No cases of Amanita phalloides induced toxic hepatitis have been identified in Korea so far.     

Mammalian transforming growth factor beta1 activated after ingestion by Anopheles stephensi modulates mosquito immunity

During the process of bloodfeeding by Anopheles stephensi, mammalian latent transforming growth factor beta1 (TGF-beta1) is ingested and activated rapidly in the mosquito midgut. Activation may involve heme and nitric oxide (NO), agents released in the midgut during blood digestion and catalysis of L-arginine oxidation by A. stephensi NO synthase (AsNOS). Active TGF-beta1 persists in the mosquito midgut to extended times postingestion and is recognized by mosquito cells as a cytokine. In a manner analogous to the regulation of vertebrate inducible NO synthase and malaria parasite (Plasmodium) infection in mammals by TGF-beta1, TGF-beta1 regulates AsNOS expression and Plasmodium development in A. stephensi. Together, these observations indicate that, through conserved immunological cross talk, mammalian and mosquito immune systems interface with each other to influence the cycle of Plasmodium development.     

Modulation of large conductance calcium-activated K+ channel by membrane-delimited protein kinase and phosphatase activities

Large conductance Ca²⁺-activated K⁺ channel was identified and studied in excised inside-out membrane patches of freshly dispersed smooth muscle cells from rabbit gastric antrum. The current-voltage relationship of the single channel was linear from -80 to +80 mV of pipette voltage in which single channel conductance was 249±17.8 pS (n=19) in symmetrical concentration of K⁺ (145mM) across the patch. Activity of the channel (NPo) depended not only on cytoplasmic calcium concentration but also on membrane potential. MgATP increased NPo in a dose-dependent manner and Mg²⁺ was prerequisite for the effect. Okadaic acid (l00nM), inhibitor of protein phosphatases, increased NPo further in the presence of MgATP. Therefore, it would be concluded that activity of the calcium-activated K⁺ channel in gastric smooth muscle cells was controlled by phosphorylation state of the channel protein and the state is further modulated by membrane-delimited protein kinase and protein phosphatase activities.     

A case of Klinefelter syndrome with retroperitoneal teratoma

Klinefelter syndrome (KS) is often associated with various neoplasms, especially germ cell tumors. Mediastinum is the most favored site of extragonadal germ cell tumors with KS, which is somewhat different from those without KS. The retroperitoneal germ cell tumor in KS is very rare. A five-month-old boy with an abdominal mass was found to have a retroperitoneal tumor. After surgical removal, he was diagnosed to have mature cystic teratoma. Cytogenetic study of his peripheral lymphocytes revealed that his karyotype was consistent with KS. This case suggests that patients with KS might be at risk of having germ cell tumors in sites other than mediastinum. It also suggests that all cases with these tumors should be screened for the presence of karyotypic abnormalities, and it might help to assess the exact correlation between germ cell tumors and KS, and to treat them accordingly.