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Patients presenting with ascites associated with peritoneal disease have a wide differential diagnosis including both malignant and non-malignant related causes. We present the unusual case of a patient, clinically deteriorating, whose malignant peritoneal disease was due to an underlying follicular lymphoma. An urgent staging CT scan followed by a peritoneal biopsy allowed the patient to start chemotherapy within days of acute presentation to the hospital. This case emphasises the importance of obtaining tissue diagnosis urgently in these patients to ensure that the correct treatment can be started in a timely manner., (2015 BMJ Publishing Group Ltd.)

Models of the outer epithelia of the human body - namely the skin, the intestine and the lung - have found valid applications in both research and industrial settings as attractive alternatives to animal testing. A variety of approaches to model these barriers are currently employed in such fields, ranging from the utilization of ex vivo tissue to reconstructed in vitro models, and further to chip-based technologies, synthetic membrane systems and, of increasing current interest, in silico modeling approaches. An international group of experts in the field of epithelial barriers was convened from academia, industry and regulatory bodies to present both the current state of the art of non-animal models of the skin, intestinal and pulmonary barriers in their various fields of application, and to discuss research-based, industry-driven and regulatory-relevant future directions for both the development of new models and the refinement of existing test methods. Issues of model relevance and preference, validation and standardization, acceptance, and the need for simplicity versus complexity were focal themes of the discussions. The outcomes of workshop presentations and discussions, in relation to both current status and future directions in the utilization and development of epithelial barrier models, are presented by the attending experts in the current report.

The respiratory route is an important portal for human exposure to a large variety of substances. Consequently, there is an urgent need for realistic in vitro strategies for evaluation of the absorption of airborne substances with regard to safety and efficacy assessment. The present study investigated feasibility of a 3D human airway epithelial model to study respiratory absorption, in particular to differentiate between low and high absorption of substances. Bronchial epithelial models (MucilAir™), cultured at the air-liquid interface, were exposed to eight radiolabeled model substances via the apical epithelial surface. Absorption was evaluated by measuring radioactivity in the apical compartment, the epithelial cells and the basolateral culture medium. Antipyrine, caffeine, naproxen and propranolol were highly transported across the epithelial cell layer (>5%), whereas atenolol, mannitol, PEG-400 and insulin were limitedly transported (<5%). Results indicate that the 3D human airway epithelial model used in this study is able to differentiate between substances with low and high absorption. The intra-experimental reproducibility of the results was considered adequate based on an average coefficient of variation (CV) of 15%. The inter-experimental reproducibility of highly absorbed compounds was in a similar range (CV of 15%), but this value was considerably higher for those compounds that were limitedly absorbed. No statistical significant differences between different donors and experiments were observed. The present study provides a simple method transposable in any lab, which can be used to rank the absorption of chemicals and pharmaceuticals, and is ready for further validation with respect to reproducibility and capacity of the method to predict respiratory transport in humans., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

New molecular diagnostic tools have recently allowed the discovery of human rhinovirus species C (HRV-C) that may be overrepresented in children with lower respiratory tract complications. Unlike HRV-A and HRV-B, HRV-C cannot be propagated in conventional immortalized cell lines and their biological properties have been difficult to study. Recent studies have described the successful amplification of HRV-C15, HRV-C11, and HRV-C41 in sinus mucosal organ cultures and in fully differentiated human airway epithelial cells. Consistent with these studies, we report that a panel of clinical HRV-C specimens including HRV-C2, HRV-C7, HRV-C12, HRV-C15, and HRV-C29 types were all capable of mediating productive infection in reconstituted 3D human primary upper airway epithelial tissues and that the virions enter and exit preferentially through the apical surface. Similar to HRV-A and HRV-B, our data support the acid sensitivity of HRV-C. We observed also that the optimum temperature requirement during HRV-C growth may be type-dependent., (© 2013 Elsevier Ltd. All rights reserved.)

Respiratory sensitizers are considered as substances of higher risk, at the same level as carcinogens, mutagens and toxic chemicals for reproduction. Presently, there is no validated assay for identifying the respiratory sensitizers. Based on a fully differentiated and functional in vitro cell model of the human airway epithelium, MucilAir™, we attempt to develop such assay. To this end, we invented a novel method, using Dextran as carrier, for applying the water insoluble chemicals to the apical surface of the airway epithelia. Using the Dextran carrier method, we successfully tested some reference chemical compounds known to cause respiratory sensitisation in human beings, including MDI, TMA and HCPt. Interestingly, these chemical sensitizers differentially up-regulated the releases of certain cytokines and chemokines involved in allergic responses. We believe that based on MucilAir™ an in vitro assay could be developed for identification and characterization of the respiratory sensitizers., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Background: Previous studies identified CD147 as the chemotactic receptor on inflammatory leukocytes for extracellular cyclophilins (eCyp). However, CD147 is not known to associate with signal transducing molecules, so other transmembrane proteins, such as proteoglycans, integrins, and CD98, were suggested as receptor or co-receptor for eCyp. CD147 is ubiquitously expressed on many cell types, but relationship between the level of CD147 expression and cellular responses to eCyp has never been analyzed. Given the role of eCyp in pathogenesis of many diseases, it is important to know whether cellular responses to eCyp are regulated at the level of CD147 expression., Results: Here, we manipulated CD147 expression levels on HeLa cells using RNAi and investigated the signalling and chemotactic responses to eCypA. Both Erk activation and chemotaxis correlated with the level of CD147 expression, with cells exhibiting low level expression being practically unresponsive to eCypA., Conclusions: Our results provide the first demonstration of a chemotactic response of HeLa cells to eCypA, establish a correlation between the level of CD147 expression and the magnitude of cellular responses to eCypA, and indicate that CD147 may be a limiting factor in the receptor complex determining cyclophilin-induced Erk activation and cell migration.

The analysis of gene expression in Arabidopsis (Arabidopsis thaliana) using cDNA microarrays and reverse transcription-polymerase chain reaction showed that AtOSA1 (A. thaliana oxidative stress-related Abc1-like protein) transcript levels are influenced by Cd2+ treatment. The comparison of protein sequences revealed that AtOSA1 belongs to the family of Abc1 proteins. Up to now, Abc1-like proteins have been identified in prokaryotes and in the mitochondria of eukaryotes. AtOSA1 is the first member of this family to be localized in the chloroplasts. However, despite sharing homology to the mitochondrial ABC1 of Saccharomyces cerevisiae, AtOSA1 was not able to complement yeast strains deleted in the endogenous ABC1 gene, thereby suggesting different function between AtOSA1 and the yeast ABC1. The atosa1-1 and atosa1-2 T-DNA insertion mutants were more affected than wild-type plants by Cd2+ and revealed an increased sensitivity toward oxidative stress (hydrogen peroxide) and high light. The mutants exhibited higher superoxide dismutase activities and differences in the expression of genes involved in the antioxidant pathway. In addition to the conserved Abc1 region in the AtOSA1 protein sequence, putative kinase domains were found. Protein kinase assays in gelo using myelin basic protein as a kinase substrate revealed that chloroplast envelope membrane fractions from the AtOSA1 mutant lacked a 70-kD phosphorylated protein compared to the wild type. Our data suggest that the chloroplast AtOSA1 protein is a new factor playing a role in the balance of oxidative stress.

Pd(II) allyl and Pd(0) olefin complexes containing the configurationally labile ligand 1,2-bis-[4,5-dihydro-3H-dibenzo[c-e]azepino]ethane were studied as models for intermediates in Pd-catalyzed allylic alkylations. According to NMR and DFT studies, the ligand prefers C(s) conformation in both eta3-1,3-diphenylpropenyl and eta3-cyclohexenyl Pd(II) complexes, whereas in Pd(0) olefin complexes it adopts different conformations in complexes derived from the two types of allyl systems in both solution and, as verified by X-ray crystallography, in the solid state. These results demonstrate that the Pd complex is capable of adapting its structure to the reacting substrate. The different structural preferences also provide an explanation for the behavior of 1,3-diphenyl-2-propenyl acetate and 2-cyclohexenyl acetate in Pd-catalyzed allylic alkylations using pseudo-C2 and pseudo-C(s) symmetric ligands.

Mast cell responses are influenced by a diverse array of environmental factors, but little is known about the effect of genetic background. In this study, we report that 129/Sv mice had high levels of circulating IgE, increased expression of the high-affinity receptor for IgE (Fc epsilonRI), and greater sensitivity to anaphylaxis when compared with C57BL/6 mice. Bone marrow-derived mast cells (BMMCs) from 129/Sv mice showed more robust degranulation upon the engagement of Fc epsilonRI. Deficiency of the Src family kinase Lyn enhanced degranulation in 129/Sv BMMCs but inhibited this response in C57BL/6 cells. C57BL/6 lyn(-/-) BMMCs had reduced expression of the Src family kinase Fyn, and increasing its expression markedly enhanced degranulation. In human mast cells the silencing of Lyn or Fyn expression resulted in hyperdegranulation or hypodegranulation, respectively. The findings demonstrate a genetic influence on the extent of a mast cell's response and identify Fyn kinase as a contributory determinant.

Mechanisms of juvenile susceptibility to cancer are not well understood. The immune response in neonates favors nonresponsiveness or T(H)2-dominant responses, raising the question of a role for neonatal immunity in this susceptibility. We have investigated the postulate that the inflammatory response differs in neonatal and adult skin. We found no inflammatory infiltrate into neonatal mouse skin in response to UV irradiation as a function of time, dose, or wavelength, although UV-induced DNA damage was readily detected. In contrast, UV irradiation of adult mice initiated a dose- and time-dependent influx of inflammatory cells, chiefly CD11b(+)Ly6G(+) neutrophils, into the skin, detected by immunohistochemistry and quantitated by FACS analysis. This inflammatory response was initiated by UVB (290-320 nm) but not by UVA (320-400 nm). Further, in neonates, in contrast to adults, neither topical trinitrochlorobenzene (TNCB) nor i.p. thioglycollate initiated an inflammatory infiltrate. Conversely, topical TNCB applied to neonates was tolerogenic, resulting in a subsequent antigen-specific decrease of the contact-hypersensitivity response in adults. Neonatal blood contained abundant neutrophils, which exhibited impaired chemotaxis to the chemokine growth-related oncogene-alpha but efficient chemotaxis to the bacterial product fMLP, concomitant with decreased expression of CXCR2 but normal levels of CD11b. We propose this neonatal deficiency in the inflammatory response is a significant, previously unrecognized factor in neonatal immune tolerance and may contribute to neonatal susceptibility to cancer, including melanoma and other UV-induced cancers.

Tumor-associated eosinophilia has been observed in numerous human cancers and several tumor models in animals; however, the details surrounding this eosinophilia remain largely undefined and anecdotal. We used a B16-F10 melanoma cell injection model to demonstrate that eosinophil infiltration of tumors occurred from the earliest palpable stages with significant accumulations only in the necrotic and capsule regions. Furthermore, the presence of diffuse extracellular matrix staining for eosinophil major basic protein was restricted to the necrotic areas of tumors, indicating that eosinophil degranulation was limited to this region. Antibody-mediated depletion of CD4+ T cells and adoptive transfer of eosinophils suggested, respectively, that the accumulation of eosinophils is not associated with T helper cell type 2-dependent immune responses and that recruitment is a dynamic, ongoing process, occurring throughout tumor growth. Ex vivo migration studies have identified what appears to be a novel chemotactic factor(s) released by stressed/dying melanoma cells, suggesting that the accumulation of eosinophils in tumors occurs, in part, through a unique mechanism dependent on a signal(s) released from areas of necrosis. Collectively, these studies demonstrate that the infiltration of tumors by eosinophils is an early and persistent response that is spatial-restricted. It is more important that these data also show that the mechanism(s) that elicit this host response occur, independent of immune surveillance, suggesting that eosinophils are part of an early inflammatory reaction at the site of tumorigenesis.

CD147 is a widely expressed plasma membrane protein that has been implicated in a variety of physiological and pathological activities. It is best known for its ability to function as extracellular matrix metalloproteinase inducer (hence the other name for this protein, EMMPRIN), but has also been shown to regulate lymphocyte responsiveness, monocarboxylate transporter expression and spermatogenesis. These functions reflect multiple interacting partners of CD147. Recently, interaction of CD147 with proteins of the cyclophilin family has been demonstrated and activity of CD147 as a signalling receptor to extracellular cyclophilins A and B has been shown. Given that extracellular cyclophilins are potent chemotactic agents for various immune cells, further studies of the role of cyclophilin-CD147 interaction in inflammation followed. They demonstrated that agents targeting CD147 or cyclophilin had a significant anti-inflammatory effect in animal models of acute or chronic lung diseases and rheumatoid arthritis. Here, we review the current knowledge about interactions between CD147 and cyclophilins.

Acute increases in the concentration of malonyl-CoA play a pivotal role in mediating the decrease in fatty acid oxidation that occurs in many tissues during refeeding after a fast. In this study, we assess whether such increases in malonyl-CoA in liver could be mediated by malonyl-CoA decarboxylase (MCD), as well as acetyl-CoA carboxylase (ACC). In addition, we examine how changes in the activity of ACC, MCD, and other enzymes that govern fatty acid and glycerolipid synthesis relate temporally to alterations in the activities of the fuel-sensing enzyme AMP-activated protein kinase (AMPK). Rats starved for 48 h and refed a carbohydrate chow diet for 1, 3, 12, and 24 h were studied. Refeeding caused a 40% decrease in the activity of the alpha1-isoform of AMPK within 1 h, with additional decreases in AMPKalpha1 activity and a decrease in AMPKalpha2 occurring between 1 and 24 h. At 1 h, the decrease in AMPK activity was associated with an eightfold increase in the activity of the alpha1-isoform of ACC and a 30% decrease in the activity of MCD, two enzymes thought to be regulated by AMPK. Also, the concentration of malonyl-CoA was increased by 50%. Between 1 and 3 h of refeeding, additional increases in the activity of ACC and decreases in MCD were observed, as was a further twofold increase in malonyl-CoA. Increases in the activity (60%) and abundance (12-fold) of fatty acid synthase occurred predominantly between 3 and 24 h and increases in the activity of mitochondrial sn-glycerol-3-phosphate acyltransferase (GPAT) and acyl-CoA:diaclyglycerol acyltransferase (DGAT) at 12 and 24 h. The results strongly suggest that early changes in the activity of MCD, as well as ACC, contribute to the increase in hepatic malonyl-CoA in the starved-refed rat. They also suggest that the changes in these enzymes, and later occurring increases in enzymes regulating fatty acid and glycerolipid synthesis, could be coordinated by AMPK.

Mannose derived hexacoordinated phosphate--prepared in two steps from methyl-alpha-D-mannopyranoside--is a chiral anionic auxiliary with broad asymmetric efficiency.

Unlabelled: Changes in the concentration of malonyl-CoA in many tissues have been related to alterations in the activity of acetyl-CoA carboxylase (ACC), the rate-limiting enzyme in its formation. In contrast, little is known about the physiological role of malonyl-CoA decarboxylase (MCD), an enzyme responsible for malonyl-CoA catabolism. In this study, we examined the effects of voluntary exercise on MCD activity in rat liver, skeletal muscle, and adipose tissue. In addition, the activity of sn-glycerol-3-phosphate acyltransferase (GPAT), which like MCD and ACC can be regulated by AMP-activated protein kinase (AMPK), was assayed. Thirty min after the completion of a treadmill run, MCD activity was increased approximately 2-fold, malonyl-CoA levels were reduced, and ACC and GPAT activities were diminished by 50% in muscle and liver. These events appeared to be mediated via activation of AMPK since: 1) AMPK activity was concurrently increased by exercise in both tissues; 2) similar findings were observed after the injection of 5-amino 4 imidazole carboxamide, an AMPK activator; 3) changes in the activity of GPAT and ACC paralleled that of MCD; and 4) the increase in MCD activity in muscle was reversed in vitro by incubating immunoprecipitated enzyme from the exercised muscle with protein phosphatase 2A, and it was reproduced by incubating immunopurified MCD from resting muscle with purified AMPK. An unexpected finding was that exercise caused similar changes in the activities of ACC, MCD, GPAT, and AMPK and the concentration of malonyl-CoA in adipose tissue., In Conclusion: MCD, GPAT, and ACC are coordinately regulated by AMPK in liver and adipose tissue in response to exercise, and except for GPAT, also in muscle. The results suggest that AMPK activation plays a major role in regulating lipid metabolism in many cells following exercise. They also suggest that in each of them, it acts to increase fatty acid oxidation and decrease its esterification.

Regulation by transforming growth factor (TGF)-beta plays an important role in immune homeostasis. TGF-beta inhibits T cell functions by blocking both proliferation and differentiation. Here we show that TGF-beta blocks Th1 differentiation by inhibiting the expression of T-bet, the apparent masterregulator of T helper (Th)1 differentiation. Restoration of T-bet expression through retroviral transduction of T-bet into developing Th1 cells abrogated the inhibitory effect of TGF-beta. In addition, we show that, contrary to prior suggestions, downregulation of interleukin 12 receptor beta2 chain is not key to the TGF-beta-mediated effect. Furthermore, we show that the direct inhibitory effect of TGF-beta on T cells is responsible, at least in part, for the inability of BALB/c mice to mount a Leishmania-specific Th1 response and to clear Leishmanial infection.

c-Jun N-terminal kinase (JNK) is a mitogen-activated protein kinase that plays important regulatory roles in helper T cell differentiation. In the current study, we used Jnk1-deficient mice to examine the function of JNK during an in vivo pathogenic infection, leishmaniasis, which is strongly influenced by Th1/Th2 effector mechanisms. The data show that Jnk1-deficient mice, despite their usually genetically resistant background, were unable to resolve Leishmania infections. Jnk1-/- mice displayed reduced delayed-type hypersensitivity in response to the pathogen, which was associated with a T cell defect. We found that, although these mice can direct an apparent Th1-response, there is also simultaneous generation of Leishmania-specific Th2 responses, which possibly down-modulate protective Th1-mediated immune function. These findings demonstrate that the negative regulation of Th2 cytokine production by the JNK1 signaling pathway is essential for generating Th1-polarized immunity against intracellular pathogens, such as Leishmania major.

We show here that maintenance of Leishmania infections with Leishmania mexicana complex parasites (Leishmania amazonensis and Leishmania pifanoi) is impaired in the absence of circulating antibody. In these studies, we used mice genetically altered to contain no circulating antibody, with and without functional B cells. This experimental design allowed us to rule out a critical role for B cell antigen presentation in Leishmania pathogenesis. In addition, we show that mice lacking the common gamma chain of Fc receptors (FcgammaRI, FcepsilonRI, and FcgammaRIII) are similarly refractory to infection with these parasites. These observations establish a critical role for antibody in the pathogenesis associated with infection by members of the L. mexicana complex.

Delivery of foreign antigens to mucosal surfaces, such as the pulmonary airways, has been shown to preferentially induce Th2-mediated responses in humans and in mice. What is not clear from these studies is whether this preferential skewing in responses is the result of the limited types of antigen being administered and/or a bias towards using particular genetic strains of mice, or whether the lung environment in itself provides a favored site for the priming of Th2-type cells. We have addressed this issue using an antigen/mouse strain combination that, under typical conditions of immunization, is strongly biased towards priming for Th1 CD4+ T cells. We show that Leishmania major parasites delivered to C57BL/6 mice via an intranasal route fail to induce the expected Th1-dominated responses and instead preferentially prime for Th2 responses. These included an influx in lymphocytes and eosinophils into alveoli, as well as the induction of Th2-type foci of inflammation around pulmonary blood vessels and airways. Moreover, high levels of Th2-associated cytokines (IL-4 and IL-5) were generated when lung-draining lymph node and tissue cells were restimulated with L. major lysate. These data suggest that the lung environment per se favors Th differentiation towards the Th2 phenotype.

Irreversible photoinactivation of photosystem II (PSII) results in the degradation of the reaction center II D1 protein. In Synechocystis PCC 6714 cells, recovery of PSII activity requires illumination. The rates of photoinactivation and recovery of PSII activity in the light are similar in cells grown in minimal (MM) or glucose-containing medium (GM). Reassembly of PSII with newly synthesized proteins requires degradation of the D1 protein of the photoinactivated PSII. This process may occur in darkness in both types of cells. The degraded D1 protein is, however, only partially replaced by newly synthesized protein in MM cells in darkness while a high level of D1 protein synthesis occurs in darkness in the GM cells. The newly synthesized D1 protein in darkness appears to be assembled with other PSII proteins. However, PSII activity is not recovered in such cells. Illumination of the cells in absence but not in the presence of protein synthesis inhibitors allows recovery of PSII activity.

The contribution of B lymphocytes as APCs for CD4+ T cell priming remains controversial, based on findings that B cells cannot provide the requisite ligating and costimulatory signals for naive T cells to be activated. In the current study, we have examined Ag-specific T:B cell collaboration under circumstances in which B cells take up Ag through Ig receptors in vivo. This results in their activation and an ability to effectively stimulate naive CD4+ T cells both in vitro and in vivo. The aim of this work was to establish some of the key molecular interactions, as well as kinetics, between Ag-specific T and B cells that enable this priming to take place. Our approach was to amplify the starting pools of both Ag-specific T and B cell populations in vivo to track directly the events during initial T:B cell collaborations. We show that the induction of optimal levels of T cell priming to a protein Ag requires the involvement of Ag-specific B cells. The interaction that results between Ag-specific T and B cells prevents the down-modulation of B7 costimulatory molecules usually observed in the absence of appropriate T cells. Moreover, this prevention in down-modulation is independent of CD40:CD40 ligand contact. Finally, we present data suggesting that once Ag-specific T and B cells interact, there is a rapid (1-2-h) down-regulation of antigenic complexes on the surface of the B lymphocytes, possibly to prevent them from engaging other T cells in the vicinity and therefore focus the initial interaction.

To define the role of CD4 in modulating T cell signaling pathways and regulating Th1 and Th2 differentiation, we have examined the activation and differentiation characteristics of naive T cells from CD4 mutant mice. Using peptides with differing affinities for the moth cytochrome c-specific TCR, we test the hypothesis that differences in coreceptor recruitment and signaling explain the qualitatively distinct signaling pathways seen in CD4 T cells following high affinity agonist and low affinity altered peptide ligand (APL) ligation. We find that the absence of CD4 signaling during stimulation with a strong agonist peptide does not qualitatively change the pattern of early TCR-mediated biochemical signaling events into a pattern resembling the response of CD4+ T cells to APLs. In contrast, the response to APL stimulation, by T cells bearing the same TCR, does require a component of CD4 signaling. The proliferative response and calcium signals normally seen following APL stimulation are markedly diminished in the absence of CD4. In addition, we find that naive T cell differentiation into Th2 effector cells is impaired in the absence of CD4. These data suggest that the altered pattern of biochemical signals generated by APLs require CD4 coreceptor function and that some of these signals may be required to initiate Th2 differentiation.

The D1 reaction center protein of the photosystem II complex is very sensitive to light. It is continuously being damaged, degraded and resynthesized. Under high light, photosystem II inactivation is observed. This is because the rate of D1 damage is faster than that of its replacement. This process can be reversed if exposure to high light is not too long. In this work we study the changes that occur in the transcriptional and translational machinery that could lead to irreversible photoinhibition in Synechocystis PCC 6714. In the first minutes of photoinhibition, high light induced an accumulation of psbA mRNA due to an increase in psbA transcription initiation. Although the transcription rate of other photosynthetic genes (e.g. psaE and cpcB-cpcA) declined, the high turnover of the psbA transcript was maintained for a long time. When the light stress was too long, the stability of psbA mRNA increased and the psbA transcription rate appeared to decrease. A high level of psbA mRNA was maintained even though translation no longer occurred and the cells were unable to recover. Experiments to measure newly synthesized D1 incorporation into the thylakoid membranes during recovery in the presence of rifampicin showed that the initiation of transcription was not required for translation of psbA mRNA when photoinhibition was still reversible. Since psbA translation did not depend on the level of psbA transcript or on the initiation of psbA transcription, we propose that damage to the translational machinery also occurred during light stress, leading to the inhibition of D1 synthesis and to irreversible photoinhibition.

T helper lymphocytes can be divided into two distinct subsets of effector cells based on their functional capabilities and the profile of cytokines they produce. The Th1 subset of CD4+ T cells secretes cytokines usually associated with inflammation, such as IFN-gamma and TNF and induces cell-mediated immune responses. The Th2 subset produces cytokines such as IL-4 and IL-5 that help B cells to proliferate and differentiate and is associated with humoral-type immune responses. The selective differentiation of either subset is established during priming and can be significantly influenced by a variety of factors. One of these factors, the cytokine environment, has been put forward as the major variable influencing Th development and is already well reviewed by others. Instead, in the current review, we focus on some of the alternative approaches for skewing Th1/Th2 responses. Specifically, we discuss the effects on Th priming of (a) using altered peptide ligands as antigens, (b) varying the dose of antigen, and (c) altering costimulatory signals. The potential importance of each of these variables to influence immune responses to pathogens in vivo is discussed throughout.

An early consequence of T cell activation is an increase in intracellular calcium concentration. Recent advances in video laser microscopic techniques enable the examination of individual cells over time following stimulation. Such studies have revealed that cells can undergo qualitatively distinct patterns of calcium mobilization, suggesting that different patterns of calcium flux may be associated with different signaling pathways and may differentially affect late events in cell activation. In this report, we identify distinct patterns of calcium mobilization in CD4+ T cells following the antibody-mediated cross-linking of either CD3 or CD4, or following the cross-linking of both CD3 and CD4 simultaneously. These effects can be further modified by the cross-linking of CD45. We find that antibody cross-linking of CD3 alone induces a single spike in the vast majority of cells shortly after the addition of the cross-linking antibody. In contrast, cross-linking CD4 alone induces a delayed pattern of repetitive calcium spikes which are decreased in amplitude compared to CD3 cross-linking. Simultaneous cross-linking of CD3 and CD4 induces a sustained increase in intracellular calcium mobilization which is dependent on the presence of extracellular calcium. This sustained increase in intracellular calcium concentration is also seen following physiologic cross-linking of CD3 and CD4 after T cell interaction with specific antigen and antigen-presenting cells. Finally, the simultaneous cross-linking of CD45, CD3 and CD4 abrogates the sustained increase in calcium seen following CD3 and CD4 cross-linking. These results suggest that the qualitative nature of T cell receptor signaling can be modulated by the molecular association of other signaling molecules, which may be part of the T cell receptor complex or not.

To determine the suitability of a new colostrum substitute derived from goat serum and to determine the amount of colostral IgG needed to achieve serum IgG concentration > 800 mg/dl, twin kids from 14 does were fed colostrum or a colostrum substitute. The volume of colostrum or colostrum substitute fed was calculated so that half the kids in each group received IgG at a low dosage (1.5 g/kg of body weight) and the other half received IgG at a high dosage (3 g/kg). Kids were bottle fed the colostrum or colostrum substitute and then fed pooled goat's milk until 18 hours old, at which time they were allowed to nurse their dams. Does were milked manually every 2 hours after parturition until specific gravity of mammary secretions was < 1.02, the specific gravity of goat's milk. Serum IgG concentration of each kid was determined by means of single radial immunodiffusion at birth and 12, 18, and 24 hours and 7, 21, and 42 days after birth. Kids were weighed at each blood collection and monitored for illness daily. None of the kids had measurable serum IgG concentrations at birth. Mean serum IgG concentration was significantly higher in kids fed colostrum than in kids fed colostrum substitute at all times, except days 7 and 42 (P < 0.05). By 24 hours after birth, serum IgG concentration was > 800 mg/dl in all kids fed colostrum, in 4 of 7 kids fed the substitute at the higher dosage, and in 2 of 7 kids fed the substitute at the lower dosage.(ABSTRACT TRUNCATED AT 250 WORDS)

A bilateral cryptorchid stallion with mild development of mammary glands was identified as an XX male by karyotyping. Necropsy revealed underdeveloped accessory sex organs and hypoplastic, inguinally located testes that were deficient of spermatogonia. Evaluation of routine hormonal profiles (without karyotyping) would have failed to diagnose this syndrome.

Primed and unprimed lymphocytes are usually classified as separate subsets of cells, based on phenotypic and functional distinctions. In the case of CD4+ T lymphocytes, primed cells are thought to proliferate more vigorously, quickly and easily, and to release a different profile of cytokines, than their naive equivalent. However, most of these data were obtained from studies in which populations of lymphocytes were compared before and after antigenic stimulation, and therefore did not distinguish between the effects resulting from the clonal expansion of specific precursor cells within such populations and those due to cell differentiation per se. We have investigated the contribution of precursor cell frequency to some of the functional changes observed in populations of CD4+ T cells following antigenic stimulation, using approaches in which antigen-specific precursor frequencies are high in both primary and secondary stimulations: mixed leukocyte reaction responses and cells from alpha beta T cell receptor transgenic mice. Our data suggest that when equivalent numbers of antigen-specific naive and previously primed CD4+ responder T cells are compared, there is no difference in their potency to proliferate but only the previously activated subset can generate cytokines such as interferon-gamma.

The in vivo cellular responses associated with the induction of specific immunity by attenuated larvae of Schistosoma mansoni in mice have been investigated. Using in vivo 5-bromo-2'-deoxyuridine incorporation, the changes in cell proliferation in the skin- and lung-draining lymph nodes (LN) of vaccinated animals were measured. A marked increase in the number of dividing cells was detected in both groups of LN, with a preferential increase in the proportion of proliferating T, relative to B, lymphocytes. Several dynamic components of cell migration have been examined to assess their relative contribution to the overall changes in the LN of immunized mice. It was determined that a significant part of the observed accumulation of cells is due to the effect of hyperaemia. There was no alteration in the affinity of the LN for T and B lymphocytes, but we concluded that the majority of recruited B cells failed to exit the nodes. The results have highlighted the importance of T cell proliferation within the draining LN for the successful immunization of mice with attenuated parasites.

This study reports on the endocrine abnormalities associated with delayed growth and puberty, observed in 10 children presenting with thalassemia major. Hormonal changes were followed up during treatment with regular transfusions and efficient chelating agents. Recovery of growth and onset of puberty were observed in most cases. When puberty was delayed, an associated substitutive treatment with sexual hormones was useful. In one case only, an isolated gonadotropic deficiency could be proven. In all cases STH, TSH and PRL secretions were normal. Without efficient and early treatment, the main consequence of the disease with respects to growth seems to be the risk of delayed puberty, mainly functional, or rarely hypogonadotropic due to definite LH and FSH deficiency.

The clinical and laboratory criteria which distinguish thalassaemia intermedia (T.I.) from thalassaemia major were analyzed in a series of 30 patients with homozygous beta- thalassaemia, 8 of whom had T.I. The appearance of the first symptoms after the age of 2 years, the moderate spleen enlargement, the haemoglobin levels approaching 8 g/100 ml and the response to moderate transfusions over 1-year observation period were in favour of T.I. Since patients who had transfusions were clinically better than those who had none, it is suggested that T.I. patients should be treated with regular transfusions and iron chelating agents.

A case of resolution of mesenteric angina is reported with percutaneous transluminal angioplasty of a superior mesenteric artery stenosis, using the Grüntzig technique with a balloon catheter. Technical aspects are described. Short-term follow-up reveals symptomatic relief, disappearance of the abdominal bruit, and normalization of d-xylose absorption.