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The intracarotid amobarbital test (IAT) is used to lateralize language function and assess hemispheric memory. In this study 23 non-lesional epileptic patients were evaluated. The magnitude of the difference in IAT scores between the two hemispheres was significantly greater in the patients whose seizures lateralized on scalp or intracranial EEG than in patients with bihemispheric seizure onset. This suggests that the IAT is useful not only in predicting lateralized seizure focus, but bihemispheric onset as well.

CD28/B7 interactions have been demonstrated to provide a co-stimulatory signal for the generation of CD8+ cytotoxic T lymphocytes in the absence of CD4+ T helper cells. The CD28 signals required for induction of cytotoxicity have yet to be described. To investigate further the biochemical signaling pathways associated with CD28-dependent cytotoxicity, we have studied the human thymic leukemia cell line, YT. YT cells kill B7+ targets in a non-major histocompatibility complex (MHC)-restricted, CD28-dependent manner. CD28 ligation on the surface of YT cells caused a rapid increase in the tyrosine phosphorylation of four major cellular substrates with masses estimated to be 110, 95, 85, and 44 kDa. The 110 and 85 kDa substrates were identified as the catalytic and regulatory subunits, respectively, of phosphatidylinositol 3-kinase (PI3-K). Engagement of CD28 caused the rapid receptor association and activation of PI3-K but did not activate phospholipase C gamma. CD28-induced tyrosine phosphorylation and PI3-K activation was independent of p56lck protein tyrosine kinase (PTK) activity (previously reported to be associated with CD28) and was insensitive to inhibition by the PTK inhibitor herbimycin A. Two structurally and mechanistically dissimilar inhibitors of PI3-K, wortmannin and 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002) also failed to block CD28-dependent tyrosine phosphorylation events or the association of PI3-K with the CD28 receptor. However, both drugs inhibited CD28-dependent cytotoxicity and CD28 receptor associated PI3-K activity with IC50 values similar to the reported IC50 values for PI3-K inhibition. Although herbimycin A did not significantly block the observed CD28-dependent tyrosine phosphorylation or PI3-K activation, herbimycin did block CD28-dependent cytotoxicity in a dose-dependent manner. These data support a role for PI3-K activation in the CD28-dependent initiation of cytotoxic effector function and suggest that a herbimycin sensitive step(s) is either CD28-independent, resides within a PI3-K-independent CD28 signaling pathway, or is downstream of CD28-dependent PI3-K activation.

Extracellular adenine nucleotides are inhibitors of the human natural killer cell line NK3.3 natural cytotoxicity activity. Natural cytotoxicity was inhibited approximately 26% by 1 m M ATP and 21% by 1 m M ADP. 5′-Adenylyl imidodiphosphate, a nonhydrolyzable ATP analog, inhibited natural cytotoxicity by 41% at a concentration of 1 m M and > 97% at a concentration of 10 m M . In contrast, AMP was not inhibitory. Adenosine was a weak inhibitor of natural cytotoxicity and may represent an alternate regulatory pathway. Removal of the nucleotides resulted in the restoration of control levels of natural cytotoxicity activity. The affinity label 5′- p -(fluorosulfonyl)benzoyladenosine (5′-FSBA) is a synthetic analog of ATP or ADP containing an electrophilic fluorosulfonyl group capable of covalently modifying proteins at adenine di- and triphosphate nucleotide-binding sites. Natural cytotoxicity was irreversibly inhibited by modification of the extracellular membrane of NK3.3 cells by 5′-FSBA. This inhibition was concentration dependent with an I 50 ∼ 100 μ M and complete inhibition at 1 m M . Modification of NK3.3 by 5′-FSBA did not affect the formation of effector—target cell conjugates; however, granule release was inhibited. This targets the site of inhibition by 5′-FSBA modification to a pathway preceding granule release. Irreversible, covalent modification of surface adenine nucleotide-binding proteins by 5′-FSBA provides a probe to study the role of specific adenine nucleotide-binding proteins in the extracellular regulation of natural killer cytolytic activity by adenine nucleotides.

The interaction of CD28 with its counter-receptor, B7, induces a cosignal in T cells required to prevent clonal anergy and to promote antigen-dependent interleukin-2 production. The molecular basis of the CD28 cosignal is not well understood but involves the activation of protein tyrosine kinase(s) (PTK). In this report we demonstrate that CD28 cross-linking on Jurkat T leukemic cells causes the activation of at least two PTK pathways. A CD28-induced, p56lck kinase-independent pathway causes tyrosine-phosphorylation of a 110-kDa substrate while recruitment of p56lck kinase activity is apparently required for CD28-induced tyrosine-phosphorylation of 97- and 68-kDa substrates as well as CD28-induced increases in intracellular calcium. The tyrosine phosphorylation of p110, but not p97 or p68, correlated with CD28 calcium-independent costimulatory activity. The pp110 molecule was tentatively identified as the catalytic subunit of phosphoinositide (PI)-3 kinase based upon its coimmunoprecipitation with the p85 regulatory subunit of PI-3 kinase. PI-3 kinase protein and catalytic activity were found complexed with the CD28 receptor if the receptor was "activated" by cross-linking on the surface of intact cells prior to detergent solubilization. The kinetics of association of PI-3 kinase with the "activated" CD28 receptor was rapid, occurring within 30 s of receptor cross-linking and was stable for at least 30 min. Analysis of the CD28 cytoplasmic peptide sequence revealed a putative PI-3 kinase src homology 2 binding motif and CD28 tyrosine phosphorylation site, DYMNM. Tyrosine phosphorylation of CD28 was detected in pervanadate-treated Jurkat B2.7 cells, but not untreated cells. Pervanadate-induced tyrosine phosphorylation of CD28 correlated with receptor association of PI-3 kinase in the absence of CD28 cross-linking, suggesting that CD28 association with PI-3 kinase uses a tyrosine phosphorylation-dependent mechanism. These data provide a model for CD28 signal transduction and support a role for PI-3 kinase in mediating the CD28 calcium-independent, cyclosporin A-insensitive costimulatory signal.

Four episodes of serious Hemophilus influenzae type b infection occurred in three children attending a day-care center. This was 100 times the expected annual total. The pharyngeal carriage rate of Hib was 60% for siblings of patients, 20% for adult household contacts, and 5% for well children at the center. No carriers were found in control populations. Escherichia coli K100, which cross-reacts serologically with Hib, was found in rectal swabs of 20% of family contacts of patients and 3.5% of well children at the center. It was recovered from two of seven persons who carried Hib in the pharynx and two of 75 who did not ( P =0.035), suggesting that carriage of one organism may facilitate carriage of the other. In a randomized prospective trial with 85 patient contact, Hib carriage was eradicated in all of four carriers given ampicillin and in all of three given rifampin. There were no statistically significant differences in the rate of adverse reactions in the two treatment groups. No further cases were reported.

Despite widespread evidence that autoimmune mechanisms may contribute to the beta cell necrosis associated with type I insulin-dependent diabetes mellitus (IDDM), it has not heretofore been demonstrated that islet cell antibodies (ICAs), directed primarily against cytoplasmic antigens, are capable of specific lysis of beta cells. We utilized a readily accessible source of mouse pancreatic islets [CBA/J mice lacking exocrine pancreas (exocrine pancreatic insufficiency syndrome)] to experimentally induce ICAs inbred mice. Homogenates of these islets were injected weekly for four weeks into syngeneic (CBA/J) and allogeneic (A/J, C57BL/6J, C57BL/KsJ) recipients. Only C57BL/KsJ inbred mice showed the induction of a high titer (greater than or equal to 160) antiserum cytotoxic to 51Cr-labeled CBA/J lymph node target cells. Neither the immunized C57BL/sJ mice with circulating ICAs nor any of the other immunized strains showed any decrease in glucose tolerance as compared with vehicle controls. Moreover, no morphologic evidence of islet necrosis or atrophy was apparent. Thus the ICAs induced were reactive with alloantigenic determinants of the donor and unreactive with antigenic determinants of the recipient strain. The C57BL/KsJ antiserum was further screened for anti-islet cell cytotoxic activity using both a 51Cr release assay from CBA/J islet cell monolayer cultures, and immunocytochemical staining of sections of Bouin's fixed, paraffin-embedded pancreas. This antiserum was cytotoxic to CBA/J beta cells in monolayer culture, but not the other non-beta islet cell types. Immune lysis of the beta cell required rabbit complement. At a concentration of 1% antiserum and 4% complement, beta cell lysis was evident between 3 and 4 h at 37 degrees C. Ultrastructural examination of beta cells exhibiting cytopathic changes revealed cytoplasmic disarray rather than any obvious lytic events at the plasma membrane. Grossly distended, rough, endoplasmic reticulum containing intracisternal type A retrovirus was the most prominent feature distinguishing antiserum and control serum-treated beta cells. This model system suggests that ICAs which recognize beta cell cytoplasmic antigens are capable of specifically lysing beta cells via a complement-dependent mechanism. Immunocytochemical staining revealed that, in addition to islet beta-cells,, the antiserum (1/500 dilution) stained a macrophage-like cell in the spleen and lymph nodes, as well as an epithelial-like cell in the thymus. The possibility is discussed that this multiple specificity may have been due to passenger leukocytes present in the islet homogenates used to immunize.

Sequential case-control studies were used to monitor changes in the clinical protection induced by group A meningococcal polysaccharide vaccine over a 3-year period. Overall, vaccine efficacy declined from 87% 1 year after vaccination to 70% and 54% at 2 and 3 years, respectively. When stratified by age at time of vaccination the data showed that, although vaccine efficacy remained high in children greater than or equal to 4 years of age (vaccine efficacy 85%, 74%, and 67% at 1, 2, and 3 years after vaccination, respectively), it declined dramatically in those less than 4 years of age at time of vaccination (vaccine efficacy 100%, 52%, and 8%, respectively, at 1, 2, and 3 years after vaccination). Thus, a single dose of group A meningococcal vaccine does not yield lasting clinical protection in children less than 4 years of age.

We have recently cloned a cDNA from the human T-cell leukemia, JURKAT, having homology with the src-like family of protein-tyrosine kinases. We have made rabbit polyclonal antibodies against the synthetic peptide CKERPEDRPTFDYLRSVLEDFFTATEGQYQPQP (cys-33-pro) deduced from the carboxy-terminal amino acid sequence predicted by the JURKAT cDNA. In this report, we demonstrate that these antibodies immunoprecipitate the protein-tyrosine kinase activity from solubilized membrane extracts from JURKAT T-leukemia cells and from human peripheral blood T-lymphocytes from normal donors. A 58 kd protein, exhibiting protein-tyrosine kinase activity, was specifically immunoprecipitated in both cases. The antibodies failed to crossreact with pp60c-src from human platelets, but did crossreact with the murine T-lymphocyte protein-tyrosine kinase, pp56T-cell.

families of patients with meningococcal disease in Sio Paulo, Brazil. The rate of meningococcal infection two weeks after treatment of carriers with sulfadiazine (49%) was greater than the rates after treatment with minocycline (17%), rifampin (9%), or the combination of minocycline and rifampin (0%). While persistence of carriage was not statistically different in the groups receiving minocycline or rifampin, seven of 69 persons (10%) receiving rifampin alone were subsequently found to carry rifampin-resistant meningococci. No minocyclineresistant meningococci were found. The most effective regimen tested for eradicating meningococcal carriage was the combination of minocycline and rifampin, but unpleasant side effects were experienced by 33% of the persons who received this combination.

Background The causes of female infertility are multifactorial and necessitate comprehensive evaluation including physical examination, hormonal testing, and imaging. Given the associated psychological and financial stress that imaging can cause, infertility patients benefit from a structured and streamlined evaluation. The goal of such a work up is to evaluate the uterus, endometrium, and fallopian tubes for anomalies or abnormalities potentially preventing normal conception. To date, the standard method for assessing these structures typically involves some combination of transvaginal sonography (TVS), hysterosalpingography (HSG), and hysteroscopy (HSC). The goal of this review is to compare the diagnostic accuracy of TVS, HSG, and HSC for diagnosing abnormalities in infertility patients to determine if all studies are necessary for pre-treatment evaluation. Results We identified infertility patients prior to initiation of assisted reproductive technology who had baseline TVS, HSG, and HSC within 180 days of each other. From medical record review, we compared frequencies of each finding between modalities. Of the 1274 patients who received a baseline TVS over 2 years, 327 had TVS and HSG within 180 days and 55 patients had TVS, HSG and HSC. Of the 327, TVS detected fibroids more often than HSG (74 vs. 5, p

Extract Sir:- We have recently encountered a case of brodifacoum poisoning in a farm dog which had access to Talon WB* rodenticide. Brodifacoum, a new warmfarin-related anticoagulant, acts by depressing the production of factors II, VII, IX, and X in the coagulation cascade. The compound is reported to be less toxic to birds and domestic animals than it is to rats and mice.(4) Few cases ofaccidental toxicity have been documented in the dog.(2) (3) We wish to draw to the attention of practitioners the possibility of accidental brodifacoum poisoning, despite the relatively high median lethal dose of 24 g of bait per kg of bodyweight for the dog.