A Novel Piperazine-Based Drug Lead for Cryptosporidiosis from the Medicines for Malaria Venture Open-Access Malaria Box

Cryptosporidiosis causes life-threatening diarrhea in children under the age of 5 years and prolonged diarrhea in immunodeficient people, especially AIDS patients. The standard of care, nitazoxanide, is modestly effective in children and ineffective in immunocompromised individuals. In addition to the need for new drugs, better knowledge of drug properties that drive in vivo efficacy is needed to facilitate drug development. We report the identification of a piperazine-based lead compound for Cryptosporidium drug development, MMV665917, and a new pharmacodynamic method used for its characterization. The identification of MMV665917 from the Medicines for Malaria Venture Malaria Box was followed by dose-response studies, in vitro toxicity studies, and structure-activity relationship studies using commercial analogues. The potency of this compound against Cryptosporidium parvum Iowa and field isolates was comparable to that against Cryptosporidium hominis Furthermore, unlike nitazoxanide, clofazimine, and paromomycin, MMV665917 appeared to be curative in a NOD SCID gamma mouse model of chronic cryptosporidiosis. MMV665917 was also efficacious in a gamma interferon knockout mouse model of acute cryptosporidiosis. To determine if efficacy in this mouse model of chronic infection might relate to whether compounds are parasiticidal or parasitistatic for C. parvum, we developed a novel in vitro parasite persistence assay. This assay suggested that MMV665917 was parasiticidal, unlike nitazoxanide, clofazimine, and paromomycin. The assay also enabled determination of the concentration of the compound required to maximize the rate of parasite elimination. This time-kill assay can be used to prioritize early-stage Cryptosporidium drug leads and may aid in planning in vivo efficacy experiments. Collectively, these results identify MMV665917 as a promising lead and establish a new method for characterizing potential anticryptosporidial agents.

αv integrins on mesenchymal cells regulate skeletal and cardiac muscle fibrosis

Mesenchymal cells expressing platelet-derived growth factor receptor beta (PDGFRβ) are known to be important in fibrosis of organs such as the liver and kidney. Here we show that PDGFRβ+ cells contribute to skeletal muscle and cardiac fibrosis via a mechanism that depends on αv integrins. Mice in which αv integrin is depleted in PDGFRβ+ cells are protected from cardiotoxin and laceration-induced skeletal muscle fibrosis and angiotensin II-induced cardiac fibrosis. In addition, a small-molecule inhibitor of αv integrins attenuates fibrosis, even when pre-established, in both skeletal and cardiac muscle, and improves skeletal muscle function. αv integrin blockade also reduces TGFβ activation in primary human skeletal muscle and cardiac PDGFRβ+ cells, suggesting that αv integrin inhibitors may be effective for the treatment and prevention of a broad range of muscle fibroses.

Higher rates of triple-class virological failure in perinatally HIV-infected teenagers compared with heterosexually infected young adults in Europe

Objectives

The aim of the study was to determine the time to, and risk factors for, triple‐class virological failure (TCVF) across age groups for children and adolescents with perinatally acquired HIV infection and older adolescents and adults with heterosexually acquired HIV infection.

Methods

We analysed individual patient data from cohorts in the Collaboration of Observational HIV Epidemiological Research Europe (COHERE). A total of 5972 participants starting antiretroviral therapy (ART) from 1998, aged < 20 years at the start of ART for those with perinatal infection and 15–29 years for those with heterosexual infection, with ART containing at least two nucleoside reverse transcriptase inhibitors (NRTIs) and a nonnucleoside reverse transcriptase inhibitor (NNRTI) or a boosted protease inhibitor (bPI), were followed from ART initiation until the most recent viral load (VL) measurement. Virological failure of a drug was defined as VL > 500 HIV‐1 RNA copies/mL despite ≥ 4 months of use. TCVF was defined as cumulative failure of two NRTIs, an NNRTI and a bPI.

Results

The median number of weeks between diagnosis and the start of ART was higher in participants with perinatal HIV infection compared with participants with heterosexually acquired HIV infection overall [17 (interquartile range (IQR) 4–111) vs. 8 (IQR 2–38) weeks, respectively], and highest in perinatally infected participants aged 10–14 years [49 (IQR 9–267) weeks]. The cumulative proportion with TCVF 5 years after starting ART was 9.6% [95% confidence interval (CI) 7.0−12.3%] in participants with perinatally acquired infection and 4.7% (95% CI 3.9−5.5%) in participants with heterosexually acquired infection, and highest in perinatally infected participants aged 10–14 years when starting ART (27.7%; 95% CI 13.2−42.1%). Across all participants, significant predictors of TCVF were those with perinatal HIV aged 10–14 years, African origin, pre‐ART AIDS, NNRTI‐based initial regimens, higher pre‐ART viral load and lower pre‐ART CD4.

Conclusions

The results suggest a beneficial effect of starting ART before adolescence, and starting young people on boosted PIs, to maximize treatment response during this transitional stage of development.

Kick the habit: a social marketing campaign by Aboriginal communities in NSW

Tackling smoking is an integral component of efforts to improve health outcomes in Aboriginal communities. Social marketing is an effective strategy for promoting healthy attitudes and influencing behaviours; however, there is little evidence for its success in reducing smoking rates in Aboriginal communities. This paper outlines the development, implementation and evaluation of Kick the Habit Phase 2, an innovative tobacco control social marketing campaign in Aboriginal communities in New South Wales (NSW). The Aboriginal Health & Medical Research Council worked with three Aboriginal communities and a creative agency to develop locally tailored, culturally relevant social marketing campaigns. Each community determined the target audience and main messages, and identified appropriate local champions and marketing tools. Mixed methods were used to evaluate the campaign, including surveys and interviews with community members and Aboriginal Community Controlled Health Service staff. Community survey participants demonstrated high recall of smoking cessation messages, particularly for messages and images specific to the Kick the Habit campaign. Staff participating in interviews reported an increased level of interest from community members in smoking cessation programs, as well as increased confidence and skills in developing further social marketing campaigns. Aboriginal community-driven social marketing campaigns in tobacco control can build capacity, are culturally relevant and lead to high rates of recall in Aboriginal communities.

Abstract 4795: Development of novel, selective, reversible inhibitors equipotent against wild-type and C481S Bruton's tyrosine kinase (BTK)

Redx Oncology has developed novel, differentiated, reversible small molecule inhibitors of BTK, combining current best-in-class potency with improved selectivity profiles, which are suitable for oral, once daily dosing, designed to be equipotent against wild-type and C481S BTK.

BTK is a member of the src-related Tec family of cytoplasmic tyrosine kinases. BTK plays a key role in the BCR signaling pathway, which is required for the development, activation and survival of B-cells. BTK inhibitors have therefore been developed with the aim of treating B-cell malignancies that are dependent on BCR signaling, such as CLL and NHL. Ibrutinib is an irreversible BTK inhibitor that has been approved for the treatment of CLL, MCL and WM.

Irreversible and covalent reversible BTK inhibitors specifically target a cysteine residue C481 within BTK. Following treatment with ibrutinib, cases of secondary resistance have emerged in both CLL and MCL patients. Acquired mutations within BTK such as C481S, C481Y, C481R, C481F have been reported in the literature and clearly interfere with covalent drug binding. It has been predicted that the incidence of observed resistance will increase as clinical use outside clinical trials expands over time. Here, we present our reversible BTK inhibitor series demonstrating subnanomolar binding affinity for WT and C481S forms of BTK, that inhibits formation of pBTK in both WT and C481S BTK expressing cells. In addition, the compound demonstrated significant in vitro potency against a number of lymphoma cell lines including inhibition of BCR signaling and proliferation in OCI-Ly10 cells at nanomolar concentrations. To further investigate the binding nature of these compounds, PBMC wash out studies, measuring CD69 as a marker of B-cell activation, were used to highlight the reversible activity of these compounds.

Some BTK inhibitors also inhibit ITK, which plays a critical role in FcR-stimulated NK cell function that is required for ADCC. ADCC is the mechanism that anti-CD20 antibodies, such as rituximab, are believed to activate, and ibrutinib has been shown to antagonize this mechanism in vitro. As rituximab-combination chemotherapy is today's standard of care in B-cell malignancies, it would be desirable to have a BTK inhibitor with high selectivity for BTK over ITK.

At 1 μM, our lead compound is highly selective when tested against 469 kinase and did not show significant inhibition against other kinases involved in BCR signaling (e.g. Syk, Lyn). Furthermore, the compound has high selectivity versus structurally related cysteine-containing kinases (including EGFR and ITK) both in enzyme and cellular assays.

Our lead compound has a favorable in vitro safety profile and drug-like properties, displaying an improved CYP profile to competitor compounds. In vivo PK demonstrated good oral bioavailability and in vivo efficacy has been demonstrated.

Citation Format: Nicolas E S Guisot, Victoria Walker, Stuart A. Best, Valentina Abet, Rose Chappell, Juliette Emmerich, Kelvin Ho, James R. Kelly, Kristina Lyons, Melanie Müller, Julienne Refuerzo, Louise Sargent, Fatima Talab, Madelene Waldron, Matilda Bingham, Mary-Ann Campbell, Caroline Phillips, Richard Armer. Development of novel, selective, reversible inhibitors equipotent against wild-type and C481S Bruton's tyrosine kinase (BTK). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4795.

Abstract A199: Development of a series of novel, potent and selective inhibitors of cFMS as a potential treatment for CSF1 expressing cancers via the modulation of the tumor microenvironment and the repolarization of macrophages

Redx Oncology has developed novel small molecule inhibitors of Colony Stimulating Factor 1 Receptor (CSF1R or cFMS) which have proven to be efficacious in an in vivo bone erosion model.

cFMS is a key receptor involved in the survival, modulation and maintenance of cells of the monocyte- macrophage lineage (which include osteoclasts in the bone). In bone, osteoclasts express cFMS whilst osteoblasts express CSF1. The CSF1/cFMS axis is involved, along with RANKL, in the dynamics of bone metabolism. Metastatic tumor cells that express cFMS can be recruited into the bone as part of this dynamic metabolism. Moreover, recent literature has shown that cFMS inhibitors are able to ‘re-educate’ pro-tumurogenic M2 macrophages, which are present in the tumor microenvironment in a CSF positive tumor, into the anti-tumurogenic M1 phenotype.

We present here results of the lead optimization of our novel cFMS inhibitor series.

REDX05182 is a lead compound from the series and is a highly selective cFMS inhibitor which shows potent inhibition of cFMS. It also inhibits the related kinases cKIT, PDGFRA and PDGFRB. Interestingly, however, it exhibits good selectivity over related kinases Flt3 and KDR (VEGFR2). It displays low nanomolar binding affinity for cFMS in a biochemical assay (6nM (5 hours)) and displays slow binding kinetics.

In cellular assays, REDX05182 shows nanomolar inhibition of CSF1 driven cell proliferation of the M-NFS-60 cell line (126nM), CSF1 stimulated phosphorylation of CSF1R in THP-1 cells (182nM) and CSF-1 stimulated differentiation of rat primary macrophages into osteoclasts (102nM).

REDX05182 demonstrates good exposure and bioavailability in vivo and has shown efficacy in a rat model of cancer induced bone resorption using MRMT-1 cancer cells. At 30mg/kg BID a statistically significant improvement in the allodynia score is observed. Also at this dose the osteoclast count in the bone is returned to that of normal bone and the osteolysis is reduced.

Interestingly, REDX05182 has also demonstrated the re-polarization of macrophages from the pro-tumurogenic M2 phenotype to the anti-tumurogenic M1 phenotype in human pBMC's.

In summary, REDX05182 is a potent cFMS inhibitor which has shown activity in vivo and in vitro. Work is continuing on the project to further optimize this lead compound to deliver a clinical candidate.

Citation Format: Sachin G. Mahale, Andrew Belfield, Jamie Wright, Mary-Ann Campbell, Matilda Bingham, Richard Armer. Development of a series of novel, potent and selective inhibitors of cFMS as a potential treatment for CSF1 expressing cancers via the modulation of the tumor microenvironment and the repolarization of macrophages. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A199.

Mitochondrial phylogeography of a Beringian relict: the endemic freshwater genus of blackfish Dallia (Esociformes)

Mitochondrial genetic variability among populations of the blackfish genus Dallia (Esociformes) across Beringia was examined. Levels of divergence and patterns of geographic distribution of mitochondrial DNA lineages were characterized using phylogenetic inference, median-joining haplotype networks, Bayesian skyline plots, mismatch analysis and spatial analysis of molecular variance (SAMOVA) to infer genealogical relationships and to assess patterns of phylogeography among extant mitochondrial lineages in populations of species of Dallia. The observed variation includes extensive standing mitochondrial genetic diversity and patterns of distinct spatial segregation corresponding to historical and contemporary barriers with minimal or no mixing of mitochondrial haplotypes between geographic areas. Mitochondrial diversity is highest in the common delta formed by the Yukon and Kuskokwim Rivers where they meet the Bering Sea. Other regions sampled in this study host comparatively low levels of mitochondrial diversity. The observed levels of mitochondrial diversity and the spatial distribution of that diversity are consistent with persistence of mitochondrial lineages in multiple refugia through the last glacial maximum.

Conference Scene: Recent developments in the understanding and treatment of hematological malignancies

The 18th Congress of the European Hematology Association, Stockholm, Sweden, 13–16 June 2013

The European Hematology Association (EHA) is a nonprofit scientific organization created in 1992, whose aim is to provide a forum for European medical professionals to unite and share research, develop education and promote excellence within the clinic. Today, the EHA has over 3000 members from various countries throughout the world, governed by an executive board and councilors elected by members. The multidisciplinary nature of the Annual Congress of the EHA is an opportunity for medical professionals with an interest in hematology to exchange information on various topics from novel therapeutics to best clinical practice, such as the ethical issues involved in biobanking. Here we have outlined some of the research that was of most interest at this meeting.

Abstract 3784: AME-133v, a humanized, Fc-engineered anti-CD20 monoclonal antibody, demonstrates greater B cell depletion than Rituxan in vitro

Purpose The efficacy of AME-133v in depleting B lymphocytes was compared in vitro to that of Rituxan, and the effect of FcαRIII genotype was assessed. Methods Blood samples from 37 healthy donors were collected and genotyped for FcαRIII polymorphism. Varying concentrations of AME-133v or Rituxan were applied to samples and CD19+ peripheral circulating B lymphocytes were measured using fluorescence-activated cell sorting (FACS). B cell depletion was listed as a percentage of baseline level. Results In an in vitro whole blood assay, AME-133v was more effective in depleting B lymphocytes from baseline levels than Rituxan, particularly at increasing concentrations (Table 1). Significant differences were found between treatments averaged over doses, between doses averaged over treatments, and between treatments depending on dose, all with p&lt;0.0001. AME-133v's superior effect in depleting B cells is independent of dose (p&lt;0.001), but caused greater B cell depletion at lower concentrations of antibody. In both AME-133v and Rituxan treatments, VF and FF patients demonstrated less B cell depletion, corroborating previous data citing decreased response to Rituxan among F-carriers and indicating improved pharmacodynamics of AME-133v. Conclusion AME-133v is engineered for a 6-fold more potent effector function in antibody-dependent cell-mediated cytotoxicity (ADCC) compared to Rituxan, which is elucidated through improved B cell depletion, across doses. Depletion in AME-133v-treated patients was also greater across all genotypes, suggesting superior pharmacodynamics of AME-133v in the low-responding F-carrier population. These findings indicate relevant biological activity of the antibody and suggest that AME-133v may provide additional clinical benefit for low-affinity FcαRIII patients. A randomized trial is being planned to compare clinical efficacy of AME-133v vs. Rituxan, targeting low-affinity FcαRIII patients.

Biochemical and structural characterization of lysophosphatidic Acid binding by a humanized monoclonal antibody

Lysophosphatidic acid (LPA) is a common product of glycerophospholipid metabolism and an important mediator of signal transduction. Aberrantly high LPA concentrations accompany multiple disease states. One potential approach for treatment of these diseases, therefore, is the therapeutic application of antibodies that recognize and bind LPA as their antigen. We have determined the X-ray crystal structure of an anti-LPA antibody (LT3015) Fab fragment in its antigen-free form to 2.15 Å resolution and in complex with two LPA isotypes (14:0 and 18:2) to resolutions of 1.98 and 2.51 Å, respectively. The variable CDR (complementarity-determining region) loops at the antigen binding site adopt nearly identical conformations in the free and antigen-bound crystal structures. The crystallographic models reveal that the LT3015 antibody employs both heavy- and light-chain CDR loops to create a network of eight hydrogen bonds with the glycerophosphate head group of its LPA antigen. The head group is almost completely excluded from contact with solvent, while the hydrocarbon tail is partially solvent-exposed. In general, mutation of amino acid residues at the antigen binding site disrupts LPA binding. However, the introduction of particular mutations chosen strategically on the basis of the structures can positively influence LPA binding affinity. Finally, these structures elucidate the exquisite specificity demonstrated by an anti-lipid antibody for binding a structurally simple and seemingly unconstrained target molecule.

Production and characterization of monoclonal anti-sphingosine-1-phosphate antibodies

Sphingosine-1-phosphate (S1P) is a pleiotropic bioactive lipid involved in multiple physiological processes. Importantly, dysregulated S1P levels are associated with several pathologies, including cardiovascular and inflammatory diseases and cancer. This report describes the successful production and characterization of a murine monoclonal antibody, LT1002, directed against S1P, using novel immunization and screening methods applied to bioactive lipids. We also report the successful generation of LT1009, the humanized variant of LT1002, for potential clinical use. Both LT1002 and LT1009 have high affinity and specificity for S1P and do not cross-react with structurally related lipids. Using an in vitro bioassay, LT1002 and LT1009 were effective in blocking S1P-mediated release of the pro-angiogenic and prometastatic cytokine, interleukin-8, from human ovarian carcinoma cells, showing that both antibodies can out-compete S1P receptors in binding to S1P. In vivo anti-angiogenic activity of all antibody variants was demonstrated using the murine choroidal neovascularization model. Importantly, intravenous administration of the antibodies showed a marked effect on lymphocyte trafficking. The resulting lead candidate, LT1009, has been formulated for Phase 1 clinical trials in cancer and age-related macular degeneration. The anti-S1P antibody shows promise as a novel, first-in-class therapeutic acting as a "molecular sponge" to selectively deplete S1P from blood and other compartments where pathological S1P levels have been implicated in disease progression or in disorders where immune modulation may be beneficial.

Direct and indirect hydrological controls on E. coli concentration and loading in midwestern streams

This study investigates hydrological controls on E. coli concentration and loading in two artificially drained agricultural watersheds (58 and 23 km(2)) of the U.S. Midwest. Stream E. coli concentrations are significantly (p < 0.02) lower at base flow than high flow; however, E. coli load is significantly higher at high flow than at low flow (p < 0.001). Although E. coli concentrations are not significantly higher (p = 0.253) in summer/fall (3269 MPN/100 mL) than in the winter/spring (2411 MPN/100 mL), E. coli load is significantly higher (p < 0.05) in winter/spring (346 MPN/day) than in summer/fall season (75 MPN/day). Correlation analysis indicates that discharge and precipitation are the best indicators of E. coli concentration and 7-d antecedent precipitation (7dP), the best indicator of E. coli loading in the watersheds studied regardless of flow conditions and location. However, E. coli concentration and loading best correlate to 7dP and turbidity at base flow. A spatial dependency is also observed at base flow with E. coli concentration and load correlating better to 7dP in the headwaters and to turbidity in the lower reaches of the watersheds studied. For high flow conditions, E. coli concentration and loading are poorly correlated to most variables, except stream water temperature and 7-d antecedent discharge. These results are consistent with those reported in the literature and suggest that, at least during base flow conditions, turbidity and 7dP may be usable in artificially drained landscapes of the Midwest to identify potential hot spots of E. coli contamination.

Anti-CD20 monoclonal antibody with enhanced affinity for CD16 activates NK cells at lower concentrations and more effectively than rituximab

Growing evidence indicates that the affinity of monoclonal antibodies (mAbs) for CD16 (FcgammaRIII) plays a central role in the ability of the mAb to mediate antitumor activity. We evaluated how CD16 polymorphisms, and mAb with modified affinity for target antigen and CD16, affect natural killer (NK) cell phenotype when CD20(+) malignant B cells were also present. The mAb consisted of rituximab (R), anti-CD20 with enhanced affinity for CD20 (AME-B), and anti-CD20 with enhanced affinity for both CD20 and CD16 (AME-D). Higher concentrations of mAb were needed to induce CD16 modulation, CD54 up-regulation, and antibody-dependent cellular cytotoxicity (ADCC) on NK cells from subjects with the lower affinity CD16 polymorphism. The dose of mAb needed to induce NK activation was lower with AME-D irrespective of CD16 polymorphism. At saturating mAb concentrations, peak NK activation was greater for AME-D. Similar results were found with measurement of CD16 modulation, CD54 up-regulation, and ADCC. These data demonstrate that cells coated with mAb with enhanced affinity for CD16 are more effective at activating NK cells at both low and saturating mAb concentrations irrespective of CD16 polymorphism, and they provide further evidence for the clinical development of such mAbs with the goal of improving clinical response to mAb.

Characterization of four rice mutants with alterations in the defence response pathway

SUMMARY A fast-neutron mutagenized population of rice seedlings was screened with Magnaporthe grisea, the causal agent of rice blast disease, to identify mutants with alterations in the defence response. Three mutant lines, ebr1, ebr2 and ebr3 (enhanced blast resistance) were identified that display enhanced resistance to M. grisea. ebr1 and ebr3 also confer enhanced resistance to the bacterial pathogen Xanthomonas oryzae pv. oryzae (Xoo). ebr3 develops a lesion mimic (LM) phenotype upon inoculation with M. grisea, and the phenotype is also induced by a shift in environmental conditions. The fourth mutant line, ncr1 (necrosis in rice), has an LM phenotype under all conditions tested and lacks enhanced resistance to either M. grisea or Xoo. Complementation testing using the mutant lines ebr3 and ncr1 indicates that the ebr3 and ncr1 loci are nonallelic and recessive. ebr1 and ebr2 display no alterations in expression of the rice pathogenesis-related (PR) genes PBZ1 and PR1, compared to wild-type CO39. ebr3 has an elevated expression of PBZ1 and PR1 only in tissue displaying the LM phenotype. ncr1 strongly expresses PBZ1 in tissue displaying the LM phenotype, whereas PR1 expression in this tissue is similar to wild-type CO39.

In vivo characterization of bioconjugate B cell toleragens with specificity for autoantibodies in antiphospholipid syndrome

This study investigated the use of well-defined bioconjugate molecules to suppress antigen-specific B cell responses to domain I (DI) of human beta(2)-glycoprotein I (beta(2)GPI) in rats. DI is the dominant target of pathogenic autoimmune antibodies in patients with antiphospholipid syndrome (APS), a disease characterized by antibody-mediated thromboembolic events. Rats primed with DI conjugated to keyhole limpet hemocyanin (DI-KLH) were rendered tolerant to subsequent antigen challenge by treatment with multivalent conjugates of DI. Antibodies to DI were suppressed 89-96% with intravenous doses of 500 micro g, and reductions were paralleled by decreases in splenic antigen-specific antibody-forming cells (AFC). Suppression was achieved with a variety of conjugates having two to four copies of DI and circulating half-lives of 2.6-8.7 h. Antibodies to KLH were not suppressed, indicating the specificity of the approach. These results establish the basis for further development of therapeutic B cell toleragens to suppress pathogenic antibodies in APS and other autoimmune diseases.

Development of Co-Dominant Amplified Polymorphic Sequence Markers in Rice that Flank the Magnaporthe grisea Resistance Gene Pi7(t) in Recombinant Inbred Line 29

ABSTRACT Pi7(t), a dominant blast resistance gene derived from the rice cultivar Moroberekan, confers complete resistance against the fungal pathogen Magnaporthe grisea. Pi7(t) previously was positioned on chromosome 11 by restriction fragment length polymorphism (RFLP) mapping of a recombinant inbred line population. One derivative of this population, recombinant inbred line (RIL)29, was designated as the representative line for Pi7(t). A segregating F2 population was created from RIL29 in order to determine the location of Pi7(t). The new mapping data indicate a position for Pi7(t) 30 centimorgans distal to the original location. Pi7(t) shares a common position with the previously mapped Pi1 M. grisea resistance gene. RIL29 carries DNA not derived from either parent used to create the RIL population at the newly assigned Pi7(t) locus. RFLP analysis has identified a possible donor source.

Multivalent Poly(ethylene glycol)-Containing Conjugates for In Vivo Antibody Suppression

Poly(ethylene glycol) (PEG) was incorporated into multivalent conjugates of the N-terminal domain of beta(2)GPI (domain 1). PEG was incorporated to reduce the rate of elimination of the conjugates from plasma and to putatively improve their efficacy as toleragens for the suppression of anti-beta(2)GPI antibodies and the treatment of antiphospholipid syndrome (APS). Three structurally distinct types of multivalent platforms were constructed by incorporating PEG into the platform structures in different ways. The amount of PEG incorporated ranged from about 5000 g per mole to about 30000 g per mole. The platforms were functionalized with either four or eight aminooxy groups. The conjugates were prepared by forming oxime linkages between the aminooxy groups and N-terminally glyoxylated domain 1 polypeptide. The plasma half-life of each conjugate, labeled with (125)I, was measured in both mice and rats. The half-lives of the conjugates ranged from less than 10 min to about 1 h in mice, and from less than 3 h to about 19 h in rats. The ability of five tetravalent conjugates to suppress anti-domain 1 antibodies in immunized rats was also measured. Incorporation of PEG in the conjugates significantly reduced the doses required for suppression, and the amount of reduction correlated with the amount of PEG incorporated.

Identification of a peptide that protects the human acetylcholine receptor against antigenic modulation

mAb 192 is a rat monoclonal antibody with very high affinity for the major immunogenic region (MIR) of the human muscle acetylcholine receptor (AChR). An epitope mimic of this antibody was selected from a phage display peptide library screened with mAb 192. The peptide-presenting phage has been shown to specifically bind to solid phase mAb 192 with an equilibrium dissociation constant (K(d)) of 8.45x10(-9) M, as directly measured with surface plasmon resonance. This value represents the avidity of the interaction between selected phage and mAb 192. A synthetic version of this peptide QPSPYNGWRMEI, referred to as MG15, binds to its selecting antibody and blocks the interaction of mAb 192 with human AChR. Peptide MG15 was able to protect acetylcholine receptors on human RD cells from antibody-mediated down-modulation. The negative charge of glutamic acid plays a important role in antibody binding. Replacement of the glutamic acid with an alanine completely abolishes the inhibitory activity.

Bioactive proteinase 3 on the cell surface of human neutrophils: quantification, catalytic activity, and susceptibility to inhibition

Although proteinase 3 (PR3) is known to have the potential to promote inflammation and injure tissues, the biologic forms and function of PR3 in polymorphonuclear neutrophils (PMN) from healthy donors have received little attention. In this paper, we show that PMN contain 3.24 +/- SD 0.24 pg of PR3 per cell, and that the mean concentration of PR3 in azurophil granules of PMN is 13.4 mM. Low levels of PR3 are detectable on the cell surface of unstimulated PMN. Exposure of PMN to cytokines or chemoattractants alone induces modest (1.5- to 2.5-fold) increases in cell surface-bound PR3. In contrast, brief priming of PMN with cytokines, followed by activation with a chemoattractant, induces rapid and persistent, 5- to 6-fold increases in cell surface expression of PR3, while causing minimal free release of PR3. Membrane-bound PR3 on PMN is catalytically active against Boc-Alanine-Alanine-Norvaline-thiobenzyl ester and fibronectin, but in marked contrast to soluble PR3, membrane-bound PR3 is resistant to inhibition by physiologic proteinase inhibitors. PR3 appears to bind to the cell surface of PMN via a charge-dependent mechanism because exposure of fixed, activated PMN to solutions having increasing ionic strength results in elution of PR3, HLE, and CG, and there is a direct relationship between their order of elution and their isoelectric points. These data indicate that rapidly inducible PR3 expressed on the cell surface of PMN is an important bioactive form of the proteinase. If PR3 expression on the cell surface of PMN is dysregulated, it is well equipped to amplify tissue injury directly, and also indirectly via the generation of autoantibodies.

Catabolism of newly synthesized decorin by explant cultures of bovine ligament

The catabolism of newly synthesized decorin by explant cultures of bovine collateral ligament was investigated. The tissue was placed in explant culture for 6 days then incubated with radiolabeled sulfate for 6 h and replaced in culture for 5 days to allow for the loss of the radiolabeled large proteoglycan. The metabolic fate of the remaining radiolabeled decorin present in the matrix of the tissue over the next 9-day period was determined. It was shown that this pool of decorin was lost from ligament explant cultures either directly into the culture medium or taken up and degraded within the cells of the tissue. The intracellular degradation of the radiolabeled pool of decorin by ligament explant cultures was shown to result in the generation of [35S]sulfate. This process required metabolically active cells and involved the lysosomal system since sulfate generation was inhibited when cultures were maintained at 4 degrees C or in the presence of either 10 mM ammonium chloride or 0. 05 mM chloroquine. The inhibition of intracellular processing of decorin resulted in an increase in the rate of loss of this proteoglycan into the medium of the cultures. The inhibition of intracellular degradation of decorin was reversible on incubation of the explant cultures at 37 degrees C or removal of ammonium chloride from the culture medium. After removal of the ammonium chloride from the culture medium the rate of intracellular catabolism was greater than that observed in cultures maintained in medium alone, which suggested that there was an intracellular accumulation of native and/or partially degraded material within the cells.

Decision making in migraine patients taking sumatriptan: an exploratory study

Until recently, much of the medical and psychological literature has examined and conceptualized the taking of medication from the viewpoint of adherence to or compliance with recommendations from health professionals. However, some authors have argued that medication taking is mostly determined by patient decision making. In order to investigate the factors and processes influencing the patient's decision to take or not take abortive therapy for migraines, 20 migraineurs (according to International Headache Society criteria) were asked, using a semistandardized interview, what factors influenced their decision to take or not take sumatriptan when they had a migraine. Qualitative analysis revealed a 2-stage decision-making process. First, the patient collects information from interoceptive and environmental cues (symptom monitoring) to predict whether the headache that is beginning will become a migraine. Then, if the patient decides it is a migraine, he or she weighs various factors to decide whether to take sumatriptan. These results are consistent with the current cognitive psychology literature on decision-making processes and could lead to significant improvements in understanding the process by which patients make decisions about taking sumatriptan and, ultimately, could lead to better patient education and more effective headache control. They also open a whole new field in the empirical investigation of medication-taking behavior.

Non-pharmacologic strategies used by adolescents for the management of menstrual discomfort

BACKGROUND

This study was a retrospective examination of adolescents' use of non-pharmacologic methods to manage menstrual discomfort.

METHODS

A convenience sample of 289 female adolescents (mean age = 16.28 years, SD = 1.00) recruited from a public high school completed a questionnaire designed for this study.

RESULTS

Ninety-eight percent of these adolescents reported using at least one non-pharmacologic method (e.g., heat, distraction) to manage menstrual discomfort. The mean perceived effectiveness of most of these methods was reported by adolescents to be below 40% (range = 3-74%).

CONCLUSION

It is possible that some methods are used because they have a physiologic impact on pain (e.g. heat), whereas others (e.g., distraction) provide a sense of comfort and control. Further research is necessary to examine the determinants of why and when certain management strategies are used by adolescents.

Quantum proteolysis by neutrophils: implications for pulmonary emphysema in alpha 1-antitrypsin deficiency

Traditional enzyme kinetics provide a poor explanation for the increased risk of lung injury in alpha 1-antitrypsin (AAT) deficiency. Millimolar concentrations of leukocyte elastase, when released from single azurophil granules of activated neutrophils, lead to evanescent quantum bursts of proteolytic activity before catalysis is quenched by pericellular inhibitors. Herein, we tested the possibility that quantum proteolytic events are abnormal in AAT deficiency. We incubated neutrophils on opsonized fluoresceinated fibronectin in serum from individuals with various AAT phenotypes, and then measured and modeled quantum proteolytic events. The mean areas of the events in serum from heterozygous individuals (Pi MZ and Pi SZ) were slightly, but significantly, larger than those in serum from normal patients (Pi M). In marked contrast, mean areas of events in serum from AAT-deficient individuals were 10-fold larger than those in serum from normal patients. Diffusion modeling predicted that local elastase concentrations exceed AAT concentrations for less than 20 milliseconds and for more than 80 milliseconds in Pi M and Pi Z individuals, respectively. Thus, quantum proteolytic events are abnormally large and prolonged in AAT deficiency, leading directly to an increased risk of tissue injury in the immediate vicinity of activated neutrophils. These results have potentially important implications for the pathogenesis and prevention of lung disease in AAT deficiency.

Recent changes in residency requirements for pediatrics: who agrees?

The purposes of this study were to determine the opinion of private and academic pediatricians about changes in pediatric residency requirements proposed by the Residency Review Committee (RRC) in October 1994 and to compare the results with the requirements finalized in February 1996 and implemented in February 1997. Surveys were mailed to all Fellows of the American Academy of Pediatrics in South Carolina. Those surveyed were asked to agree or disagree with 57 proposed changes. The level of agreement among all groups of pediatricians was very high; however there were significant differences between groups of pediatricians. Many controversial items were modified or deleted in the final version.

"U" curve association of blood pressure and mortality in hemodialysis patients. Medical Directors of Dialysis Clinic, Inc

BACKGROUND

Hypertension may play an important role in the pathogenesis of the excess cardiovascular and cerebrovascular (CV) morbidity observed in hemodialysis patients (HD). However, the optimal blood pressure (BP) range for HD patients has not been defined. We postulated that there is a "U" curve relationship between BP and CV mortality. To explore this hypothesis we studied 5,433 HD patients in Dialysis Clinic Inc., a large not-for-profit chain, over a five year period.

METHODS

Cox regression, with fixed and time-varying covariates, was used to assess the effect of systolic blood pressure (SBP) and diastolic blood pressure (DBP), pre- and post-dialysis, on CV mortality, while adjusting for age, gender, ethnicity, primary cause of end-stage renal disease, Kt/V, serum albumin, and antihypertensive medications.

RESULTS

The overall impact of BP on CV mortality was modest. Pre-dialysis, neither systolic nor diastolic hypertension were associated with an increase in CV mortality. Post-dialysis, SBP > or = 180 mm Hg (RR = 1.96, P < 0.015) and DBP > or = 90 mm Hg (RR = 1.73, P < 0.05) were associated with increased CV mortality. Low SBP (SBP < 110 mm Hg) was associated with increased CV mortality, pre- and post-dialysis.

CONCLUSIONS

The results suggest the presence of a "U" curve relationship between SBP post-dialysis and CV mortality in HD patients.

Optimal selectin-mediated rolling of leukocytes during inflammation in vivo requires intercellular adhesion molecule-1 expression

Leukocyte interactions with vascular endothelium during inflammation occur through discrete steps involving selectin-mediated leukocyte rolling and subsequent firm adhesion mediated by members of the integrin and Ig families of adhesion molecules. To identify functional synergy between selectin and Ig family members, mice deficient in both L-selectin and intercellular adhesion molecule 1 (ICAM-1) were generated. Leukocyte rolling velocities in cremaster muscle venules were increased significantly in ICAM-1-deficient mice during both trauma- and tumor necrosis factor alpha-induced inflammation, but rolling leukocyte flux was not reduced. Elimination of ICAM-1 expression in L-selectin-deficient mice resulted in a sharp reduction in the flux of rolling leukocytes during tumor necrosis factor alpha-induced inflammation. The observed differences in leukocyte rolling behavior demonstrated that ICAM-1 expression was required for optimal P- and L-selectin-mediated rolling. Increased leukocyte rolling velocities presumably translated into decreased tissue emigration because circulating neutrophil, monocyte, and lymphocyte numbers were increased markedly in L-selectin/ICAM-1-deficient mice. Furthermore, neutrophil emigration during acute peritonitis was reduced by 80% in the double-deficient mice compared with either L-selectin or ICAM-1-deficient mice. Thus, members of the selectin and Ig families function synergistically to mediate optimal leukocyte rolling in vivo, which is essential for the generation of effective inflammatory responses.

Behaviours caregivers use to determine pain in non-verbal, cognitively impaired individuals

To create a checklist of behaviours that caregivers could use to determine pain in non-verbal individuals with mental retardation, primary caregivers were recruited by the Division of Neurology and interviewed using a semistructured interview. Caregivers of 20 individuals were asked to recall two instances of short, sharp pain and two of longer-lasting pain and describe the individual's behaviour. Transcribed interviews were reviewed by two of the authors and sets of non-overlapping items were developed. Average age of the 20 individuals was 14.5 years (range 6 to 29 years) and language level averaged 10 months as scored by the MacArthur Communicative Development Inventory. All had mental retardation and 18 had epilepsy and spastic quadriplegia or hemiparesis. Thirty-one behaviours were extracted from the interviews. The specific behaviours were often different from one child to another but the classes of behaviours (Vocal, Eating/Sleeping, Social/Personality, Facial expression of pain, Activity, Body and limbs, and Physiological) were common to almost all children. Reliability of using the checklist on interviews was very good (kappa=0.77). The checklist has excellent content validity and will be useful for caregivers of cognitively-impaired, non-verbal individuals to report on pain behaviours. Further research is needed to additionally assess its validity and sensitivity.

The P-selectin glycoprotein ligand-1 is important for recruitment of neutrophils into inflamed mouse peritoneum

The P-selectin glycoprotein ligand-1 (PSGL-1) is a high-affinity ligand of P-selectin on myeloid cells and certain subsets of lymphoid cells. We generated the rat monoclonal antibody (MoAb) 2PH1 that recognizes an epitope within the first 19 amino acids at the N-terminus of the processed form of mouse PSGL-1. This antibody blocks attachment of mouse myeloid cells to P-selectin under both static and flow conditions. Intravenous administration of saturating amounts of 2PH1 reduced the number of rolling leukocytes in venules of the acutely exposed mouse cremaster muscle by 79% (+/-5.7%), whereas an anti-P-selectin MoAb reduced it completely. Examining the effect of the MoAb 2PH1 on the recruitment of neutrophils into chemically inflamed mouse peritoneum showed that blocking PSGL-1 inhibited neutrophil accumulation in the peritoneum by 82% (+/-7%) at 2 hours and by 59% (+/-7.9%) at 4 hours after stimulation. A similar effect was seen with the MoAb against P-selectin. Simultaneous administration of both antibodies at the 4-hour time point blocked neutrophil accumulation by 86% (+/-4.2%), arguing for an additional partner molecule for PSGL-1 besides P-selectin. This is the first demonstration of the importance of PSGL-1 in the recruitment of mouse neutrophils into inflamed tissue.

Use of medication by adolescents for the management of menstrual discomfort

OBJECTIVE

To determine how adolescents use medication to manage menstrual discomfort.

DESIGN

Survey.

SETTING

Public high school.

PARTICIPANTS

Convenience sample of 386 adolescent girls (80% return rate: 10 refusals and 8 exclusions). Two hundred and ninety-one cases were used for analyses (16.26+/-1.00 years [mean+/-SD]; range, 14-21 years), distributed equivalently across grades 10 through 12. Parent's socioeconomic status was predominately class III or lower on Hollingshead's Two-Factor Index of Social Status. Eighty-five percent of the subjects were English Canadian.

MAIN OUTCOME MEASURES

The Menstrual Distress Management Questionnaire (designed for our study to measure disability and medication use) and the Symptom Severity Scale.

RESULTS

Ninety-three percent reported menstrual discomfort during the last 3 menstruations and 70% of these had used over-the-counter (OTC) medications to manage the discomfort. Users of OTC medications reported greater symptom severity and disability than non-OTC users. Seventy-five percent of the OTC medication users took within the recommended dose of 1 to 2 pills, but 57% took medication less often than the maximum daily frequency. The size of a single dose of OTC medication was correlated with how often OTC medication was taken (r[s]=0.40, P<.001). Seventeen percent used prescription medication and reported significantly greater symptom severity and disability than nonprescription medication users. Seventy-one percent of the prescription drug users took the prescribed amount, 13% took less, and 16% took more.

CONCLUSIONS

Adolescent girls frequently suffer from menstrual discomfort and use OTC medications to manage the discomfort, but they may not be using OTC medications effectively. There are possible explanations for medicating behavior and future research directions should be considered.

Cytokines regulate membrane-bound leukocyte elastase on neutrophils: a novel mechanism for effector activity

Membrane-bound leukocyte elastase activity on neutrophils may have potent proinflammatory effects. Herein, we report the effects of tumor necrosis factor-alpha (TNF-alpha), platelet-activating factor (PAF), N-formyl-leucyl-methionyl-phenylalanine (fMLP), and interleukin-8 (IL-8) on membrane-bound elastase expression. TNF-alpha or PAF alone induced only approximately two- to threefold increases in membrane-bound elastase but exhibited marked dose- and time-dependent priming effects for subsequent stimulation with fMLP or IL-8 (up to 20-fold increases in membrane-bound human leukocyte elastase compared with unstimulated cells). Optimally PAF-primed and fMLP-stimulated cells expressed 1.105 +/- 0.25 (SD) x 10(-17) mol [6.65 +/- 1.51 (SD) x 10(6) molecules] membrane-bound elastase activity/cell or approximately 12% of the content of unstimulated cells. Elastase binds to the cell surface by a charge-dependent mechanism since 1) incubation of cells with cationic molecules abrogated agonist-induced upregulation of membrane-bound elastase and 2) elastase was progressively eluted from the cell surface by solutions with increasing ionic strength. Thus interactions between proinflammatory mediators strikingly upregulate membrane-bound elastase on neutrophils, which may promote inflammatory responses and/or contribute to tissue injury.

Hepatitis: implications for dialysis personnel

Hepatitis B and C are readily transmitted blood-borne viruses encountered in dialysis settings. The current recommendations for control of these hepatitis viruses are discussed in this article.

Characterization of a large chondroitin sulfate proteoglycan present in bovine collateral ligament

Bovine collateral ligament synthesized a 35S-labeled large proteoglycan species which eluted with a Kav of approximately 0.27 on Sepharose CL-2B and contained only chondroitin sulfate chains with a molecular mass of approximately 32 kDa. Fluorography of the 35S-labeled core proteins derived from the large ligament proteoglycan revealed a broad range of molecular masses above approximately 200 kDa, which was of comparable size to the four major endogenous core protein bands derived from this proteoglycan detected with 5/6/3-B-3, an antibody directed against terminal unsaturated chondroitin-6-sulfate disaccharides. The core proteins derived from the large ligament proteoglycan exhibited immunoreactivity of 12/21/1-C-6, an antibody specific for a peptide epitope common to both the G1 and G2 domains of aggrecan. Four major core protein bands with molecular masses greater than approximately 200 kDa derived from the large ligament proteoglycan, were detected using the antibodies raised against versican from bovine aorta or human fibroblasts. Compared with aggrecan, the 35S-labeled large ligament proteoglycan was distributed over a broader range of buoyant densities in an associative caesium chloride density gradient. This polydispersity may be indicative of differences in the degree of glycosylation as well as heterogeneity in the size of the large ligament proteoglycan core proteins. The 35S-labeled large ligament proteoglycan also demonstrated the ability to form complexes with an aggrecan aggregate preparation, the majority of which could not be dissociated by the presence of HA10-50. These findings indicate that the large chondrotin sulfate proteoglycan synthesized by bovine collateral ligament may be a versican-like proteoglycan which exhibited the potential to form like protein-stabilized complexes.

Catabolism and loss of proteoglycans from cultures of bovine collateral ligament

This paper investigates the kinetics and mechanism of loss of the two major proteoglycan species from cultures of bovine collateral ligament. Following incubation of ligament with [35S]sulfate after 6 days in culture, the rate of loss of the predominant proteoglycan species, decorin, from the matrix was shown to be much slower (t1/2 approximately 18 days) than that of the large chondroitin sulfate proteoglycan (t1/2 approximately 1.4 days). Analysis of 35S-labeled proteoglycans released into the medium between Days 11 and 15 of the culture period on a column of Sepharose CL-4B revealed that these macromolecules constituted mainly decorin of similar hydrodynamic size to that present in the matrix. Furthermore, analysis of core proteins using gel electrophoresis followed by fluorography or immunodetection with LF-94, an antibody directed against the amino-terminal region of decorin, indicated that the core proteins of decorin released into the medium and those remaining in the matrix of ligament cultures had a similar molecular mass (approximately 49 kDa). Analysis of both the 35S-labeled and endogenous macromolecules using 5/6/3-B-3, an antibody directed against terminal unsaturated chondroitin-6-sulfate disaccharides, revealed that three core proteins with molecular masses greater than approximately 200 kDa were present in the matrix. Four additional core proteins (range approximately 80-200 kDa) derived from the large proteoglycan were detected in the medium of ligament cultures. These findings indicate that, unlike decorin, the loss of the large chondroitin sulfate proteoglycan from the matrix of ligament cultures involved proteolytic cleavage of its core protein. No difference in the hydrodynamic size of the 35S-labeled glycosaminoglycan chains derived from either proteoglycan species remaining in the matrix or released into the medium of ligament cultures was observed.

Inducible binding of bioactive cathepsin G to the cell surface of neutrophils. A novel mechanism for mediating extracellular catalytic activity of cathepsin G

Catalytically active cathepsin G that is bound to the cell surface of human neutrophils may play a variety of roles in normal neutrophil biology and in pathobiology associated with inflammation. In this study, we describe expression of neutrophil cell surface-bound cathepsin G in response to TNF-alpha and platelet-activating factor (PAF) under conditions in which minimal free release of cathepsin G is detected. TNF-alpha and PAF alone induced modest (two- to threefold) increases in cell surface-bound cathepsin G, but exhibited a marked dose- and time-dependent priming effect for subsequent chemoattractant-induced responses (up to 15- to 25-fold increases in cell surface expression). When optimally primed (TNF-alpha, 100 U/ml, or PAF, 10(-9) M), neutrophils expressed five- to sixfold more cell surface-bound cathepsin G, in comparison with cells exposed to FMLP alone. Priming responses were more rapid with PAF (15 s to 5 min) than with TNF-alpha (1 to 60 min). Optimally primed and FMLP-stimulated neutrophils express approximately 160 ng of catalytically active cathepsin G per 10(6) cells, which represents approximately 11% of the cellular content of unstimulated cells. Cathepsin G binds to the cell surface by a charge-dependent mechanism since: 1) incubation of cells with highly positively charged molecules abrogated agonist-induced up-regulation of the cell surface expression of cathepsin G and 2) cathepsin G was eluted from the cell surface by high concentrations of NaCl. These data indicate that interactions between biologically relevant pro-inflammatory cytokines and chemoattractants serve to markedly up-regulate cell surface-bound cathepsin G. The focused catalytic activity of cell surface-bound cathepsin G may alter endothelial and epithelial barriers, promote thrombogenesis, injure extracellular matrix, and/or facilitate directed migration of neutrophils during inflammation.

Inducible binding of bioactive cathepsin G to the cell surface of neutrophils. A novel mechanism for mediating extracellular catalytic activity of cathepsin G

Catalytically active cathepsin G that is bound to the cell surface of human neutrophils may play a variety of roles in normal neutrophil biology and in pathobiology associated with inflammation. In this study, we describe expression of neutrophil cell surface-bound cathepsin G in response to TNF-alpha and platelet-activating factor (PAF) under conditions in which minimal free release of cathepsin G is detected. TNF-alpha and PAF alone induced modest (two- to threefold) increases in cell surface-bound cathepsin G, but exhibited a marked dose- and time-dependent priming effect for subsequent chemoattractant-induced responses (up to 15- to 25-fold increases in cell surface expression). When optimally primed (TNF-alpha, 100 U/ml, or PAF, 10(-9) M), neutrophils expressed five- to sixfold more cell surface-bound cathepsin G, in comparison with cells exposed to FMLP alone. Priming responses were more rapid with PAF (15 s to 5 min) than with TNF-alpha (1 to 60 min). Optimally primed and FMLP-stimulated neutrophils express approximately 160 ng of catalytically active cathepsin G per 10(6) cells, which represents approximately 11% of the cellular content of unstimulated cells. Cathepsin G binds to the cell surface by a charge-dependent mechanism since: 1) incubation of cells with highly positively charged molecules abrogated agonist-induced up-regulation of the cell surface expression of cathepsin G and 2) cathepsin G was eluted from the cell surface by high concentrations of NaCl. These data indicate that interactions between biologically relevant pro-inflammatory cytokines and chemoattractants serve to markedly up-regulate cell surface-bound cathepsin G. The focused catalytic activity of cell surface-bound cathepsin G may alter endothelial and epithelial barriers, promote thrombogenesis, injure extracellular matrix, and/or facilitate directed migration of neutrophils during inflammation.

Cell surface-bound elastase and cathepsin G on human neutrophils: a novel, non-oxidative mechanism by which neutrophils focus and preserve catalytic activity of serine proteinases

Serine proteinases of human polymorphonuclear neutrophils play an important role in neutrophil-mediated proteolytic events; however, the non-oxidative mechanisms by which the cells can degrade extracellular matrix in the presence of proteinase inhibitors have not been elucidated. Herein, we provide the first report that human neutrophils express persistently active cell surface-bound human leukocyte elastase and cathepsin G on their cell surface. Unstimulated neutrophils have minimal cell surface expression of these enzymes; however, phorbol ester induces a 30-fold increase. While exposure of neutrophils to chemoattractants (fMLP and C5a) stimulates modest (two- to threefold) increases in cell surface expression of serine proteinases, priming with concentrations of lipopolysaccharide as low as 100 fg/ml leads to striking (up to 10-fold) increase in chemoattractant-induced cell surface expression, even in the presence of serum proteins. LPS-primed and fMLP-stimulated neutrophils have approximately 100 ng of cell surface human leukocyte elastase activity per 10(6) cells. Cell surface-bound human leukocyte elastase is catalytically active, yet is remarkably resistant to inhibition by naturally occurring proteinase inhibitors. These data indicate that binding of serine proteinases to the cell surface focuses and preserves their catalytic activity, even in the presence of proteinase inhibitors. Upregulated expression of persistently active cell surface-bound serine proteinases on activated neutrophils provides a novel mechanism to facilitate their egress from the vasculature, penetration of tissue barriers, and recruitment into sites of inflammation. Dysregulation of the cell surface expression of these enzymes has the potential to cause tissue destruction during inflammation.

Identification of a RAPD marker linked to the pendula gene in Norway spruce (Picea abies (L.) Karst. f. pendula)

The pendula phenotype of Norway spruce [Picea abies (L.) Karst f. pendula] is characterized by narrow crowns and strong apical dominance and is controlled by a single dominant gene (P). This defined genetic control presents one of the few opportunities to map a single gene controlling a morphological trait in a forest tree. We used random amplified polymorphic DNA (RAPD) markers and bulked segregant analysis to identify one locus OPH10_720, linked to the pendula gene. The estimated recombination frequency (r) between OPH10_720 and P was 0.046 (SE r =0.032). Mapping of the pendula gene is an important first step towards the ultimate identification and cloning of this gene.

Catabolism of aggrecan by explant cultures of human articular cartilage in the presence of retinoic acid

The N-terminal amino acid sequence of human aggrecan was determined and it was shown that two sequences were present. The major sequence, AVTVE-, accounted for 60% of the aggrecan and started at alanine residue 17 of the human aggrecan core protein cDNA sequence (K. Doege et al. (1991) J. Biol. Chem. 266, 894-920). The other N-terminal sequence, VETX-, started at valine residue 20. Characterization of aggrecan core protein peptides present in the matrix of adult human articular cartilage showed that at least 11 aggrecan core proteins were present with approximate M(r) between 300,000 and 43,000. All these core proteins were found to have the same N-terminal sequences as that observed in human aggrecan. When articular cartilage was placed in explant culture in medium containing 10(-6) M retinoic acid there was a 3.5-fold increase in the loss of aggrecan into the culture medium compared to tissue maintained in medium alone or medium containing 20% (v/v) newborn calf serum. Analysis of the aggrecan core protein fragments that were released to the culture medium containing 10(-6) M retinoic acid showed the presence of 13 core protein peptides of M(r) between 300,000 and 43,000. The 11 smaller peptides of M(r) 230,000 to 43,000 were shown to have the N-terminal sequence ARGS-. This sequence which starts at residue 393 of the human aggrecan core protein is located within the interglobular region between the G1 and G2 domains and is the site of aggrecan catabolism by the putative protease aggrecanase. The presence of core proteins of varying sizes but with the same N-terminal sequence reflects proteolytic processing from the C-terminal end of the core protein that was also observed in the aggrecan macromolecules extracted from the matrix of human articular cartilage. This proteolytic processing was also evident but to a lesser extent in newly synthesized 35S-labeled aggrecan macromolecules.

Phosphotyrosine-dependent association between CD22 and protein tyrosine phosphatase 1C

CD22 is a B lymphocyte-specific cell surface glycoprotein that becomes tyrosine phosphorylated upon B cell activation. To determine if tyrosine phosphorylated CD22 couples signaling through membrane immunoglobulin (mIg) to down-stream elements, we looked for molecules coprecipitating with CD22 after anti-Ig stimulation. We found that a 60-kDa molecule was stably associated with CD22 following cross-linking of mIg and have identified this molecule as protein tyrosine phosphatase 1C (PTP1C). The association between PTP1C and CD22 is dependent upon tyrosine phosphorylation of CD22, but does not appear to require tyrosine phosphorylation of PTP1C.

Tyrosine phosphorylation of VCP, the mammalian homologue of the Saccharomyces cerevisiae CDC48 protein, is unusually sensitive to stimulation by sodium vanadate and hydrogen peroxide

A mAb produced by immunization of mice with tyrosine-phosphorylated proteins from activated B lymphocytes was found to recognize valosin-containing protein (VCP). VCP is the mammalian homologue of the Saccharomyces cerevisiae CDC48 protein and has localized regions of sequence identity with the yeast Sec18 and Pas1 proteins and the mammalian NSF protein, all of which are important in intracellular vesicular traffic or formation. VCP was found to be constitutively phosphorylated on tyrosine in Rous sarcoma virus-transformed fibroblasts. Phosphorylation of VCP on tyrosine was stimulated only modestly during activation of B lymphocytes by ligation of membrane Ig. In contrast, treatment of B cells with either H2O2 or a combination of H2O2 and Na3VO4 greatly increased tyrosine phosphorylation of VCP. These results may suggest that under normal conditions tyrosine phosphorylation of VCP has a rapid turnover and that it can be detected easily only when dephosphorylation is inhibited by artificial means.

Tyrosine phosphorylation of VCP, the mammalian homologue of the Saccharomyces cerevisiae CDC48 protein, is unusually sensitive to stimulation by sodium vanadate and hydrogen peroxide

A mAb produced by immunization of mice with tyrosine-phosphorylated proteins from activated B lymphocytes was found to recognize valosin-containing protein (VCP). VCP is the mammalian homologue of the Saccharomyces cerevisiae CDC48 protein and has localized regions of sequence identity with the yeast Sec18 and Pas1 proteins and the mammalian NSF protein, all of which are important in intracellular vesicular traffic or formation. VCP was found to be constitutively phosphorylated on tyrosine in Rous sarcoma virus-transformed fibroblasts. Phosphorylation of VCP on tyrosine was stimulated only modestly during activation of B lymphocytes by ligation of membrane Ig. In contrast, treatment of B cells with either H2O2 or a combination of H2O2 and Na3VO4 greatly increased tyrosine phosphorylation of VCP. These results may suggest that under normal conditions tyrosine phosphorylation of VCP has a rapid turnover and that it can be detected easily only when dephosphorylation is inhibited by artificial means.

Cytochemical characteristics of neurons in the trigeminal mesencephalic nucleus of hatchling chicks

The goal of the present study was to identify cytochemical markers characteristic of muscle afferents in hatchling chicks. To this end, we stained neurons in the trigeminal mesencephalic nucleus with a variety of markers that label subsets of neurons in avian dorsal root ganglia. We found that trigeminal mesencephalic neurons are surprisingly heterogeneous in their cytochemical make-up, expressing, to varying degrees, substance P, cholecystokinin, carbonic anhydrase, calbindin D-28k, parvalbumin, and S-100 beta. Calbindin D28k and S-100 beta appeared to be expressed equally in medial and lateral divisions of the trigeminal mesencephalic nucleus. In contrast, substance P- and cholecystokinin-immunoreactive neurons were more abundant in the medial division, whereas carbonic anhydrase activity and parvalbumin immunoreactivity were stronger in the lateral division. We were unable to detect met-enkephalin, neuropeptide Y, calcitonin gene-related peptide, vasoactive intestinal peptide, somatostatin, gamma-aminobutyric acid, or tyrosine hydroxylase in the trigeminal mesencephalic nucleus. Moreover, these neurons did not appear to bind the lectin Dolichos biflorus agglutinin. The heterogeneity of expression of markers among trigeminal mesencephalic nucleus neurons, especially between neurons in the medial and lateral divisions, suggests that these neurons are functionally diverse.

Monocytes recruited to sites of inflammation express a distinctive proinflammatory (P) phenotype

Only a minor proportion of monocytes responds to chemoattractants. To test the possibility that chemoattractant-responsive monocytes have distinctive functional characteristics, we enriched or depleted monocyte preparations for cells having a proinflammatory (P) phenotype and tested their responses to biologically relevant chemoattractants. We prepared monocyte subpopulations by one of three independent techniques to minimize the chances of artifacts: 1) depletion of P monocytes by adherence to fibronectin; 2) enrichment for P monocytes by negative selection for HLA-DR antigen; and 3) flow cytometric sorting. We measured responsiveness of monocyte subpopulations to N-formyl-Met-Leu-Phe, C5a, zymosan-activated serum, and monocyte chemoattractant protein-1 by three parameters: 1) polarization, 2) actin polymerization, and 3) directed migration. With each chemoattractant and each parameter, there was a striking direct relationship between the responsiveness of the monocyte preparations and their content of P monocytes. Our data indicate that the capacity of monocytes to be recruited rapidly from the vasculature into sites of inflammation is a property of a subpopulation of monocytes with a distinctive, neutrophil-like proinflammatory phenotype.

A discrete subpopulation of human monocytes expresses a neutrophil-like proinflammatory (P) phenotype

We have demonstrated that a discrete and naturally occurring subpopulation of human monocytes expresses a neutrophil-like proinflammatory (P) phenotype. P monocytes constitute 20-30% of the circulating monocyte pool and are characterized by 1) avid adherence to extracellular matrix through high-level cell-surface expression of alpha 5-, beta 1-, and beta 2-integrins; 2) high capacity to produce reactive oxygen species; 3) high content of serine proteinases and alpha 1-proteinase inhibitor; and 4) proteolytic activity against a soluble peptide human leukocyte elastase substrate, [3H]elastin, and solid-phase fibronectin, even in the presence of proteinase inhibitors. However, P monocytes express little or no cell-surface HLA-DR antigen, suggesting that they are unable to participate in specific immune responses. In contrast, the remainder of circulating monocytes have a low proinflammatory potential but contain the population of monocytes with high-level expression of HLA-DR antigen. P monocytes can readily be separated from the remainder of monocytes on the basis of 1) their capacity to adhere to fibronectin; and 2) their absent expression of HLA-DR antigen when flow cytometry or immunomagnetic beads are used. Our data indicate that, when recruited to sites of inflammation, P monocytes can either promote resolution of inflammation or contribute to tissue injury.

Personality, stress, coping, and sense of coherence among nephrology nurses in dialysis settings

The goal of this study was to examine the relationships among personality types, personal and work-related stress, coping resources, and sense of coherence (SOC) among nephrology nurses in dialysis settings. Nurses (n = 49) from 13 dialysis units in New Mexico completed a demographic data form, Perceived and Nursing Stress Scales, SOC Scale, Coping Resources Inventory, and the Myers-Briggs Type Indicator (MBTI). The results indicated that there was a positive correlation between perceived personal stress and work-related stress, especially work load. Conversely, there were negative correlations between (a) both personal and work-related stress with SOC, and (b) both coping resources and SOC with burnout. High levels of personal and work-related stress were related to inadequate coping resources. Regression analysis indicated that the main contributing factors to emotional exhaustion (a major component of burnout) were low SOC, lack of staff support, personal stress, and heavy work load. Increased utilization of coping resources may facilitate the nurses' management of personal and work-related stressors.

Characterization of extracellular matrix macromolecules from bovine synovial capsule

Synovial capsule from the metacarpophalangeal joints of cattle was shown to be a highly collagenous tissue, with a hydroxyproline content of 100 +/- 1 micrograms/mg dry weight and a water content of 70 +/- 3.6%. Type-I collagen made up 83% of the collagen present, and the remainder was type III. When incubated in explant culture, synovial capsule incorporated [3H]acetate into both glycoproteins and hyaluronan and [3H]acetate and [35S]sulfate into proteoglycans. The rate of synthesis of proteoglycans by synovial tissue was shown to be similar to that measured for collateral ligament from the same joint. Two populations of proteoglycans were observed to be synthesized by synovial capsule. More than 90% of the 35S-labelled proteoglycans eluted with a K(av) of 0.7 on Sepharose CL-4B, and the remainder of the radiolabelled macromolecules eluted from the column with a K(av) of less than 0.5. Analysis of the major population of proteoglycans showed it to consist of a dermatan sulfate-containing proteoglycan with a core protein of 45,000 Da that had the same N-terminal amino acid sequence as decorin.

The nature of feared outcome representations in children

The present study investigated the way in which feared outcomes are organized in long-term memory in children and adolescents. A list of items relating to threatening outcomes, originally generated by children, was given to an additional 560 children (aged 6 to 16) and rated for the degree to which they worried about each. Factor analysis revealed two interpretable factors of feared outcomes. The first factor centered on concerns about physical harm while the second factor centered on social consequences that children and adolescents worry about. The two factors were consistent across gender, age, and clinical status. A scale involving the maximally discriminating items showed good internal consistency and test-retest reliability.

Work stress, burnout, and sense of coherence among dialysis nurses

The overall goal of this study was to examine the relationship among work stressors, burnout, and sense of coherence (SOC) in dialysis nurses. Two hundred thirty-eight registered nurses from 56 dialysis units completed a demographic data form, the Nursing Stress Scale, the Maslach Burnout Inventory, and Antonovsky's Sense of Coherence Scale. The results indicated that work load was the major contributing factor to both overall stress and burnout. Understanding the stressors that affect responses to the work environment will allow for successful interventions to alter the risk of exhaustion and burnout.