Search for gluinos and squarks using like-sign dileptons in pp macro collisions at square root of s = 1.8 TeV

We present results of the first search for like-sign dilepton ( e(+/-)e(+/-), e(+/-)mu(+/-), mu(+/-)mu(+/-)) events associated with multijets and large missing energy using 106 pb(-1) of data in pp macro collisions at square root of s = 1.8 TeV collected during 1992-1995 by the CDF experiment. Finding no events that pass our selection, we examine pair production of gluinos (tilde g) and squarks (tilde q) in a constrained framework of the minimal supersymmetric standard model. At tan beta = 2 and mu = -800 GeV/c(2), we set 95% confidence level limits of M(tilde g)>221 GeV/c(2) for M(tilde g) approximately M(tilde q), and M(tilde q)>168 GeV/c(2) for M(tilde q)>>M(tilde g), both with small variation as a function of mu.

Observation of diffractive J/psi production at the Fermilab Tevatron

We report the first observation of diffractive J/psi(--> mu+mu-) production in pp collisions at root square[s] = 1.8 TeV. Diffractive events are identified by their rapidity gap signature. In a sample of events with two muons of transverse momentum p(mu)T>2 GeV/c within the pseudorapidity region /eta/ < 1.0, the ratio of diffractive to total J/psi production rates is found to be R(J/psi) = [1.45 +/- 0.25]%. The ratio R(J/psi)(x) is presented as a function of x-Bjorken. By combining it with our previously measured corresponding ratio R(jj)(x) for diffractive dijet production, we extract a value of 0.59 +/- 0.15 for the gluon fraction of the diffractive structure function of the proton.

Search for quark-lepton compositeness and a heavy W' Boson using the enu channel in p p macro collisions at square root of [s] = 1.8 TeV

We present searches for quark-lepton compositeness and a heavy W' boson at high electron-neutrino transverse mass. We use approximately 110 pb(-1) of data collected in p p macro collisions at square root of [s] = 1.8 TeV by the CDF Collaboration during 1992-1995. The data are consistent with standard model expectations. Limits are set on the quark-lepton compositeness scale Lambda, the ratio of partial cross sections sigma(W'-->enu)/sigma(W-->enu), and the mass of a W' boson with standard model couplings. We exclude Lambda<2.81 TeV and a W' boson with mass below 754 GeV/c(2) at the 95% confidence level. Combining with our previously published limit obtained using the muon channel, we exclude a W' boson with mass below 786 GeV/c(2) at the 95% confidence level.

Charged-particle multiplicity pp collisions at square root of (s) = 1.8 TeV

We report on a measurement of the mean charged-particle multiplicity of jets in dijet events with dijet masses in the range 80-630 GeV/c(2), produced at the Tevatron in pp collisions with square root (s) = 1.8 TeV and recorded by the Collider Detector at Fermilab. The data are fit to perturbative-QCD calculations carried out in the framework of the modified leading log approximation and the hypothesis of local parton-hadron duality. The fit yields values for two parameters in that framework: the ratio of parton multiplicities in gluon and quark jets, r identical withN(g-jet)(partons)/N(q-jet)(partons) = 1.7+/-0.3, and the ratio of the number of charged hadrons to the number of partons in a jet, K(charged)(LPHD) identical with N(charged)(hadrons)/N(partons) = 0.57+/-0.11.

Double diffraction dissociation at the Fermilab Tevatron collider

We present results from a measurement of double diffraction dissociation in pp collisions at the Fermilab Tevatron collider. The production cross section for events with a central pseudorapidity gap of width Deltaeta(0)>3 (overlapping eta = 0) is found to be 4.43+/-0.02(stat)+/-1.18(syst) mb [ 3.42+/-0.01(stat)+/-1.09(syst) mb] at square root of (s) = 1800[630] GeV. Our results are compared with previous measurements and with predictions based on Regge theory and factorization.

Measurement of d sigma/dM and forward-backward charge asymmetry for high-mass Drell-Yan e(+)e(-) pairs from pp macro collisions at square root of s = 1.8 TeV

We report on a measurement of the mass dependence of the forward-backward charge asymmetry, A(FB), and production cross section d sigma/dM for e(+)e(-) pairs with mass M(ee)>40 GeV/c(2). The data sample consists of 108 pb(-1) of pp macro collisions at square root of s = 1.8 TeV taken by the Collider Detector at Fermilab during 1992-1995. The measured asymmetry and d sigma/dM are compared with the predictions of the standard model and a model with an extra Z' gauge boson.

Measurement of the top quark p(T) distribution

We have measured the p(T) distribution of top quarks that are pair produced in pp collisions at sqrt[s] = 1.8 TeV using a sample of tt decays in which we observe a single high- p(T) charged lepton, a neutrino, and four or more jets. We use a likelihood technique that corrects for the experimental bias introduced due to event reconstruction and detector resolution effects. The observed distribution is consistent with the standard model prediction. We use these data to place limits on the production of high- p(T) top quarks suggested in some models of anomalous top quark pair production.

Changes in the haemagglutinin and the neuraminidase genes prior to the emergence of highly pathogenic H7N1 avian influenza viruses in Italy

Outbreaks of avian influenza due to an H7N1 virus of low pathogenicity occurred in domestic poultry in northern Italy from March 1999 until December 1999 when a highly pathogenic avian influenza (HPAI) virus emerged. Nucleotide sequences were determined for the HA1 and the stalk region of the neuraminidase (NA) for viruses from the outbreaks. The HPAI viruses have an unusual multibasic haemagglutinin (HA) cleavage site motif, PEIPKGSRVRRGLF. Phylogenetic analysis showed that the HPAI viruses arose from low pathogenicity viruses and that they are most closely related to a wild bird isolate, A/teal/Taiwan/98. Additional glycosylation sites were present at amino acid position 149 of the HA for two separate lineages, and at position 123 for all HPAI and some low pathogenicity viruses. Other viruses had no additional glycosylation sites. All viruses examined from the Italian outbreaks had a 22 amino acid deletion in the NA stalk that is not present in the N1 genes of the wild bird viruses examined. We conclude that the Italian HPAI viruses arose from low pathogenicity strains, and that a deletion in the NA stalk followed by the acquisition of additional glycosylation near the receptor binding site of HA1 may be an adaptation of H7 viruses to a new host species i.e. domestic poultry.

Search for neutral supersymmetric Higgs bosons in pp collisions at sqrt[s] = 1.8TeV

We present the results of a search for neutral Higgs bosons produced in association with b quarks in pp-->bb(phi)-->bbb final states with 91+/-7 pb(-1) of pp collisions at sqrt[s] = 1.8 TeV recorded by the Collider Detector at Fermilab. We find no evidence of such a signal and the data are interpreted in the context of the neutral Higgs sector of the minimal supersymmetric extension of the standard model. With basic parameter choices for the supersymmetric scale and the stop-quark mixing, we derive 95% C.L. lower mass limits for neutral Higgs bosons for tan(beta) values in excess of 35.

Production of chi(c1) and chi(c2) in pp collisions at sqrt[S] = 1.8 TeV

We have measured the ratio of prompt production rates of the charmonium states chi(c1) and chi(c2) in 110 pb(-1) of pp collisions at sqrt[s] = 1.8 TeV. The photon from their decay into J/psi(gamma) is reconstructed through conversion into e+e- pairs. The energy resolution this technique provides makes the resolution of the two states possible. We find the ratio of production cross sections sigma(chi(c2))/sigma(chi(c1)) = 0.96+/-0.27(stat)+/-0.11(syst) for events with pT(J/psi) > 4.0 GeV/c, /eta(J/psi)/ < 0.6, and pT(gamma) > 1.0 GeV/c.

First measurement of the ratio B(t --> Wb)/B(t --> Wq) and associated limit on the Cabibbo-Kobayashi-Maskawa element /V(tb)/

We present the first measurement of the ratio of branching fractions R identical withB(t-->Wb)/B(t-->Wq) from p_p collisions at sqrt[s] = 1.8 TeV. The data set corresponds to 109 pb(-1) of data recorded by the Collider Detector at Fermilab during the 1992-95 Tevatron run. We measure R = 0.94(+0.31)(-0.24)(stat+syst) or R>0.61 (0.56) at 90% (95)% C.L., in agreement with the standard model predictions. This measurement yields a limit on the Cabibbo-Kobayashi-Maskawa quark mixing matrix element /V(tb)/ under the assumption of three generations and unitarity.

Natural-resistance-associated macrophage protein 1 is an H+/bivalent cation antiporter

In mammals, natural-resistance-associated macrophage protein 1 (Nramp1) regulates macrophage activation and is associated with infectious and autoimmune diseases. Nramp2 is associated with anaemia. Both belong to a highly conserved eukaryote/prokaryote protein family. We used Xenopus oocytes to demonstrate that, like Nramp2, Nramp1 is a bivalent cation (Fe2+, Zn2+ and Mn2+) transporter. Strikingly, however, where Nramp2 is a symporter of H+ and metal ions, Nramp1 is a highly pH-dependent antiporter that fluxes metal ions in either direction against a proton gradient. At pH 9.0, oocytes injected with cRNA from wild-type murine Nramp1 with a glycine residue at position 169 (Nramp1(G169); P=3.22x10(-6)) and human NRAMP1 (P=3.87x10(-5)) showed significantly enhanced uptake of radiolabelled Zn2+ compared with water-injected controls. At pH 5.5, Nramp1(G169) (P=1.34x10(-13)) and NRAMP1 (P=1.09x10(-6)) oocytes showed significant efflux of Zn2+. Zn2+ transport was abolished when the proton gradient was dissipated using carbonyl cyanide p-trifluoromethoxyphenylhydrazone. Using pre-acidified oocytes, currents of 130+/-57 nA were evoked by 100 microM Zn2+ at pH 7.5, and 139+/-47 nA by 100 microM Fe2+ at pH 7.0, in Nramp1(G169) oocytes; currents of 254+/-49 nA and 242+/-26 nA were evoked, respectively, in NRAMP1 oocytes. Steady-state currents evoked by increasing concentrations of Zn2+ were saturable, with apparent affinity constants of approx. 614 nM for Nramp1(G169) and approx. 562 nM for NRAMP1 oocytes, and a curvilinear voltage dependence of transporter activity (i.e. the data points approximate to a curve that approaches a linear asymptote). In the present study we propose a new model for metal ion homoeostasis in macrophages. Under normal physiological conditions, Nramp2, localized to early endosomal membranes, delivers extracellularly acquired bivalent cations into the cytosol. Nramp1, localized to late endosomal/lysosomal membranes, delivers bivalent cations from the cytosol into this acidic compartment where they may directly affect antimicrobial activity.

Alternate splicing at the 3'-end of the human pancreatic tumor-associated mucin MUC4 cDNA

MUC4 is a membrane-bound mucin and is considered as the human homologue of the rat sialomucin complex (SMC). The deduced structural organization of the wild type-MUC4 cDNA (WT-MUC4) sequence revealed two subunits: a large amino mucin type subunit (MUC4alpha) and a transmembrane subunit (MUC4beta). MUC4beta is a membrane-bound growth factor like subunit and contains three EGF-like domains. The MUC4 gene is expressed in several normal tissues like trachea, lung, and testis. It is not expressed in a normal human pancreas; however, its dysregulation results in high levels of expression in pancreatic tumors and tumor cell lines. Recently, we have demonstrated the presence of alternative splice events in the 3'-end of the MUC4 cDNA that generated new putative variants (sv1-sv10) in normal human testis and in a pancreatic tumor cell line (HPAF). In search of MUC4 variant(s) that are specific to pancreatic adenocarcinoma, we investigated the splicing phenomena in the MUC4 cDNA sequence by using a large panel of pancreatic tumor cell lines. We have identified ten alternative splice events located downstream to the central large tandem repeat domain. These splice events generated 12 variant species (sv4, sv9, sv10-18, and sv21) of MUC4 cDNAs. The deduced amino acid sequence of these variant MUC4 cDNAs revealed two distinct types: a family of secreted and a membrane-associated variant form. Among the members of MUC4 secreted variant family, three (sv4, sv12, and sv13) of ten showed a short 144 residue COOH-terminus compared to 1154 residues in WT-MUC4. The variants with this short COOH-terminus (144 residues) was found in 37% (4/11) of the tumor lines. The putative membrane-bound variant sv10 was detected in 37% (4/11) pancreatic tumor cell lines but not in any normal human tissues. In conclusion, we have identified novel splice variant(s) of MUC4 in pancreatic adenocarcinoma.

Comparison of generic and proprietary sodium stibogluconate for the treatment of visceral leishmaniasis in Kenya

OBJECTIVE

To compare the use of generic and proprietary sodium stibogluconate for the treatment of visceral leishmaniasis (kala-azar).

METHODS

A total of 102 patients with confirmed kala-azar were treated in a mission hospital in West Pokot region, Kenya, with sodium stibogluconate (20 mg/kg/day for 30 days)--either as Pentostam (PSM) or generic sodium stibogluconate (SSG); 51 patients were allocated alternately to each treatment group.

FINDINGS

There were no significant differences in baseline demographic characteristics or disease severity, or in events during treatment. There were 3 deaths in the PSM group and 1 in the SSG group; 2 patients defaulted in each group. Only 1 out of 80 test-of-cure splenic aspirates was positive for Leishmania spp.; this patient was in the SSG group. Follow-up after > or = 6 months showed that 6 out of 58 patients had relapsed, 5 in the SSG group and 1 in the PSM group. No outcome variable was significantly different between the two groups.

CONCLUSION

The availability of cheaper generic sodium stibogluconate, subject to rigid quality controls, now makes it possible for the health authorities in kala-azar endemic areas to provide treatment to many more patients in Africa.

Direct compression tablets containing a series of four beta-cyclodextrin complexes formed by neutralizing an acidic drug

A series of four beta-cyclodextrin complexes (called products) was formed by neutralizing an acidic drug to study the effect of drug solubility on complex formation and the dissolution performance from direct compression tablets. Four solid products were prepared by neutralizing the drug in 0.05, 0.10, 0.20, and 0.30 M tromethamine solutions with a constant 0.09 M beta-cyclodextrin concentration, filtering the solutions, and removing the water through evaporation with heat and vacuum. The four products contained drug and water in a distinct relationship, thus suggesting a complex formation that was dependent on the tromethamine concentration. Infrared, powder X-ray diffraction, differential scanning calorimetry (DSC), phase solubility, and scanning electron microscopy (SEM) techniques revealed distinct differences among the four products, suggesting three of the four products were complexes, and one product was either a weak complex or a physical mixture. Ultraviolet (UV) analysis showed no evidence of complex formation. Phase solubility results showed one product had a slight increase in drug solubility, and three products had no increase in drug solubility with increasing beta-cyclodextrin concentration. The lack of a solubility increase suggests insoluble complex formation. Drug dissolution in water was improved significantly in all tablets containing either a product or a physical mixture when compared to the pure drug. The products prepared with the two highest concentrations of tromethamine showed a dissolution performance that was superior to all other formulations. Enthalpy measurements by DSC were a good indicator of dissolution performance for tablets containing the four products. Drug dissolution through salt formation in the absence of beta-cyclodextrin showed the drug-salt dissolution varied from better to worse when compared to the dissolution profiles of the four products. The varying dissolution performance was attributed to the formation of distinct beta-cyclodextrin complexes with varing solubilities.

Transforming growth factor-beta is an autocrine mitogen for a novel androgen-responsive murine prostatic smooth muscle cell line, PSMC1

A prostatic smooth muscle cell line (PSMC1) was established from the dorsolateral prostate of p53 null mice. The cell line is nontumorigenic when inoculated subcutaneously, under the renal capsule or intraprostatically in syngeneic mice. These cells express alpha-smooth muscle actin (alpha-SMA), indicating their smooth muscle origin, and TGF-beta significantly enhances expression of alpha-SMA. The cells express both androgen receptor (AR) mRNA and protein, and respond mitogenically to physiological concentrations of androgens. PSMC1 cells produce significant amounts of TGF-beta, which stimulates growth by an autocrine mechanism. Dihydrotestosterone (DHT) increases proliferation of PSMC1 cells by promoting TGF-beta secretion. Considering the significant inhibitory effect of TGF-beta on prostatic epithelial cells and its stimulatory effect on the PSMC1 cells, we postulate that TGF-beta produced by prostatic smooth muscle cells may have a paracrine effect on the prostatic epithelium. We also postulate that TGF-beta may be involved in the etiology of benign prostatic hyperplasia (BPH) by stimulating excessive stromal proliferation. Line PSMC1 is the first reported androgen-responsive murine smooth muscle cell line. It will be useful for in vivo and in vitro experiments to study the mechanisms of androgen action on prostatic stroma and for delineating the interactions that occur between prostatic smooth muscle and epithelium that may lead to prostatic diseases such as BPH.

Measurement of J/psi and psi(2S) polarization in pp collisions at sqrt[s] = 1.8 TeV

We have measured the polarization of J/psi and psi(2S) mesons produced in pp collisions at sqrt[s] = 1.8 TeV, using data collected at the Collider Detector at Fermilab during 1992-1995. The polarization of promptly produced J/psi [psi(2S)] mesons is isolated from those produced in B-hadron decay, and measured over the kinematic range 4 [5.5]<P(T)<20 GeV/c and |y|<0.6. For P(T) greater than or approximately equal 12 GeV/c we do not observe significant polarization in the prompt component.

Fas ligand-deficient gld mice are more susceptible to graft-versus-host-disease

BACKGROUND

The Fas/Fas ligand (FasL) pathway plays an important role in a number of apoptotic processes that could be important for the development of graft-versus-host disease (GVHD) after bone marrow transplantation (BMT), such as cytolysis of target cells by cytotoxic T cells, regulation of inflammatory responses, peripheral deletion of autoimmune cells, costimulation of T cells, and activation-induced cell death.

METHODS

To study the role of the Fas/FasL pathway in the complex pathophysiology of graft versus host disease (GVHD), we used FasL-deficient B6.gld mice as recipients in a Major Histocompatibility Antigen Complex-matched minor Histocompatibility Antigen-mismatched murine model for GVHD after allogeneic BMT (C3H.SW-->B6).

RESULTS

We found a significantly higher morbidity and mortality from GVHD compared to control B6 recipients. Histopathological analysis of the GVHD target organs demonstrated that B6.gld recipients developed significantly more thymic and intestinal GVHD. B6gld recipients with GVHD demonstrated an increased expansion of donor T cells and monocytes/ macrophages compared to control B6 recipients, whereas serum TNF-alpha levels were equivalent in B6.gld recipients and control B6 recipients.

CONCLUSION

This study demonstrates that the expression of FasL in the BMT recipient is important for the host's ability to control GVHD.

Generation of active TGF-beta by prostatic cell cocultures using novel basal and luminal prostatic epithelial cell lines

Two prostatic epithelial lines, one of basal origin and one of luminal origin, were established from the dorsolateral prostates of p53 null mice. The cell lines are nontumorigenic when inoculated subcutaneously under the renal capsule or intraprostatically in syngeneic mice. The luminal cell line (PE-L-1) expresses cytokeratins 8 and 18 and the basal cell line (PE-B-1) expresses cytokeratins 5 and 14. The basal cells require serum for growth, whereas the luminal cells grow only in serum-free medium. Both cell lines require the presence of growth factors for optimal growth in culture, with EGF and FGF-2 having the greatest effect on the growth rate. Both lines express androgen receptor (AR) mRNA and protein. Androgen stimulates growth of the basal cell line, indicating that the ARs are functional, whereas growth of the luminal cells is unaffected by androgens. The luminal line is significantly inhibited by exogenous TGF-beta and produces low levels of endogenous TGF-beta. In contrast, the basal cell line produces significant amounts of TGF-beta and its growth is not influenced by this cytokine. Coculture of luminal cells with prostatic smooth muscle cells results in the generation of increased levels of biologically active TGF-beta, indicating a paracrine mechanism of TGF-beta activation that may be involved in the maintenance of normal prostatic function. To our knowledge this is the first report describing both basal and luminal prostatic cell lines from a single inbred animal species and the first indication that prostatic epithelial and stromal cells interact to generate the biologically active form of TGF-beta. These lines will provide an important model for determining basal/luminal interactions in both in vitro and in vivo assays.

Search for scalar top and scalar bottom quarks in pp collisions at square root s=1.8 TeV

We have searched for direct pair production of scalar top and scalar bottom quarks in 88 pb-1 of pp collisions at sqrt[s]=1.8 TeV with the CDF detector. We looked for events with a pair of heavy flavor jets and missing energy, consistent with scalar top (bottom) quark decays to a charm (bottom) quark and a neutralino. The numbers of events that pass our selections show no significant deviation from standard model expectations. We compare our results to the next-to-leading order scalar quark production cross sections to exclude regions in scalar quark-neutralino mass parameter space.

Search for a W' boson via the decay mode W'-->munumu in 1.8 TeV pp collisions

We report the results of a search for a W' boson produced in pp collisions at a center-of-mass energy of 1.8 TeV using a 107 pb-1 data sample recorded by the Collider Detector at Fermilab. We consider the decay channel W'-->&munumu and search for anomalous production of high transverse mass munumu lepton pairs. We observe no excess of events above background and set limits on the rate of W' boson production and decay relative to standard model W boson production and decay using a fit of the transverse mass distribution observed. If we assume standard model strength couplings of the W' boson to quark and lepton pairs, we exclude a W' boson with invariant mass less than 660 GeV/c2 at 95% confidence level.

In vitro activity of four fluoroquinolones against clinical isolates of Pseudomonas aeruginosa determined by the E test

Ciprofloxacin, levofloxacin, ofloxacin, and trovafloxacin were tested by the E-test against 100 clinical isolates of Pseudomonas aeruginosa. Ciprofloxacin was the most active of the tested agents with 82% of isolates having a MIC </=1 mg/l (range: 0.094->8). Levofloxacin and trovafloxacin had nearly identical potency: 75% and 76% of the isolates were inhibited by </=2 mg/l of these agents, respectively (range: 0.125->8 for levofloxacin; 0.19->8 for trovafloxacin). Ofloxacin was the least active of the four quinolones, with 43% of the isolates having a MIC >2 mg/l. All isolates resistant to ciprofloxacin were also resistant to the other agents, i.e. resistance to ciprofloxacin predicted resistance to all the quinolones tested in every case. This data demonstrates that fluoroquinolones are active agents against P. aeruginosa. In vitro susceptibility testing, however, is crucial to assess the resistance pattern in any specific location and for each individual agent.

Effects of radiation on a model of malignant glioma invasion

We sought to characterize the effects of radiation alone and in combination with BCNU and dexamethasone on malignant glioma invasion. A model of malignant glioma invasion into a gel matrix of collagen type I was used to characterize response to radiation treatment for four malignant glioma cell lines (C6, U251, U373, A172) and nine primary human glioblastoma explants. A radiation dose dependent inhibition of invasion was noted for the C6 astrocytoma cell line but not the other cell lines or explants. Addition of BCNU and dexamethasone to radiation produced additional inhibition of invasion among the cell lines and explants but could not suppress invasion entirely.

The effects of pregnancy and smooth muscle contractility on cervical distensibility in the rat

OBJECTIVE

We sought to compare distensibility of the isolated rat cervix from nonpregnant rats (n = 6), rats at midgestation (n = 5), and rats at term gestation (n = 4).

STUDY DESIGN

The cervix was excised, and one cervical channel was cannulated from both ends and positioned in the organ chamber for perfusion-superfusion by a peristaltic pump at an intraluminal pressure of 30 mm Hg for 30 minutes. After the equilibration period, perfusion was stopped, the outlet was closed, and the cervix was inflated with a syringe pump. The volume was increased at a rate of 3.33 microL/s until intraluminal pressure reached approximately 120 mm Hg. The outlet was then opened, and the cervix was perfused at 30 mm Hg of intraluminal pressure for another 30 minutes. The volume-pressure relationships were obtained 3 times without any agent present and in the presence of 60-mmol/L potassium chloride or 10(-4)-mol/L 3-morpholinosydnonimine hydrochloride (also known as SIN-1).

RESULTS

The volume-pressure relationship was shifted to the right during progression of pregnancy, demonstrating increased compliance of the cervix. The nonspecific depolarizing agent potassium chloride or the nitric oxide donor 3-morpholinosydnonimine did not affect volume-pressure relationships in cervices from nonpregnant rats, rats at midgestation, or rats at term gestation.

CONCLUSION

The volume-pressure relationship in the isolated cannulated rat cervix reflects the resistance of the organ to increased intraluminal pressure. The compliance of the cervix is increased as pregnancy progresses, demonstrating decreased resistance to stretch. Activation or inhibition of cervical smooth muscle does not contribute to the physical properties of the cervix, which controls compliance-resistance.

Graft-versus-host-disease-associated thymic damage results in the appearance of T cell clones with anti-host reactivity

BACKGROUND

We studied whether T-cell clones, which appear in the periphery as a result of the failure of thymic negative selection during graft-versus-host disease (GVHD), have any in vivo anti-host reactivity and can cause GVHD in an adoptive transfer model.

METHODS

We performed our studies in a murine model (B10.BR into CBA/J) for allogeneic bone marrow transplantation with major histocompatibility complex-matched and minor histocompatibility antigen-mismatched unrelated donors and unique Vbeta T-cell deletion patterns in donors and recipients.

RESULTS

GVHD resulted in the appearance of Vbeta6+ T cells as a result of a loss of negative selection. We found that Vbeta6+ T cells from normal donors proliferated in vitro and in vivo. Depletion of Vbeta6+ T cells from the donor T-cell inoculum resulted in less GVHD morbidity and a decrease in the loss of thymic cellularity. To test the anti-host reactivity of de novo generated Vbeta6+ T cells in animals with GVHD, we developed an adoptive transfer model of splenic T cells from CBA/J host animals with GVHD into sublethally irradiated CBA/J recipients Depletion of Vbeta6+ T cells from the splenic T cells before adoptive transfer could significantly decrease the transient GVHD morbidity in the sublethally irradiated hosts.

CONCLUSIONS

Our data indicate that GVHD-associated thymic damage results in a loss of thymic negative selection, which leads to the appearance of T-cell clones with anti-host reactivity in vitro and in vivo.

Fas-deficient lpr mice are more susceptible to graft-versus-host disease

The Fas/Fas ligand (FasL) pathway is involved in a variety of regulatory mechanisms that could be important for the development of graft-vs-host disease (GVHD) after bone marrow transplantation (BMT), such as cytolysis of target cells by cytotoxic T cells, regulation of inflammatory responses, peripheral deletion of autoimmune cells, costimulation of T cells, and activation-induced cell death. To further evaluate the role of Fas/FasL in the complex pathophysiology of GVHD, we used Fas-deficient B6.lpr mice as recipients in a MHC-matched minor histocompatibility Ag-mismatched murine model for GVHD after allogeneic BMT (C3H.SW-->B6). We found a significantly higher morbidity and mortality from GVHD compared with control B6 recipients. In contrast, B6.lpr recipients had very little hepatic GVHD, although all other specific GVHD target organs (skin, intestines, and thymus) were more severely affected than in the control B6 recipients. B6.lpr recipients with GVHD demonstrated intact donor lymphoid engraftment and an increase in expansion of donor T cells and monocytes/macrophages compared with control B6 recipients. Serum levels of IFN-gamma and TNF-alpha were higher in B6.lpr recipients than in control B6 recipients, and monocytes/macrophages in B6.lpr recipients appeared more sensitized. B6.lpr recipients had more residual peritoneal macrophages after BMT, and peritoneal macrophages from B6.lpr mice could induce a greater proliferative response from C3H.SW splenocytes. This study demonstrates that the expression of Fas in the recipient is required for GVHD of the liver, but shows unexpected consequences when host tissues lack the expression of Fas for the development of GVHD in other organs and systemic GVHD.

Brain insulin receptors and spatial memory. Correlated changes in gene expression, tyrosine phosphorylation, and signaling molecules in the hippocampus of water maze trained rats

Evidence accumulated from clinical and basic research has indirectly implicated the insulin receptor (IR) in brain cognitive functions, including learning and memory (Wickelgren, I. (1998) Science 280, 517-519). The present study investigates correlative changes in IR expression, phosphorylation, and associated signaling molecules in the rat hippocampus following water maze training. Although the distribution of IR protein matched that of IR mRNA in most forebrain regions, a dissociation of the IR mRNA and protein expression patterns was found in the cerebellar cortex. After training, IR mRNA in the CA1 and dentate gyrus of the hippocampus was up-regulated, and there was increased accumulation of IR protein in the hippocampal crude synaptic membrane fraction. In the CA1 pyramidal neurons, changes in the distribution pattern of IR in particular cellular compartments, such as the nucleus and dendritic regions, was observed only in trained animals. Although IR showed a low level of in vivo tyrosine phosphorylation, an insulin-stimulated increase of in vitro Tyr phosphorylation of IR was detected in trained animals, suggesting that learning may induce IR functional changes, such as enhanced receptor sensitivity. Furthermore, a training-induced co-immunoprecipitation of IR with Shc-66 was detected, along with changes in in vivo Tyr phosphorylation of Shc and mitogen-activated protein kinase, as well as accumulation of Shc-66, Shc-52, and Grb-2 in hippocampal synaptic membrane fractions following training. These findings suggest that IR may participate in memory processing through activation of its receptor Tyr kinase activity, and they suggest possible engagement of Shc/Grb-2/Ras/mitogen-activated protein kinase cascades.

Characterization and radiation resistance of new isolates of Rubrobacter radiotolerans and Rubrobacter xylanophilus

In this study we characterized new strains of the slightly thermophilic species Rubrobacter radiotolerans and the thermophilic species Rubrobacter xylanophilus, both of which were previously represented only by the type strains isolated, respectively, from Japan and the United Kingdom. The new isolates were recovered from two hot springs in central Portugal after gamma irradiation of water and biofilm samples. We assessed biochemical characteristics, performed DNA-DNA hybridization, and carried out 16S rDNA sequence analysis to demonstrate that the new Rubrobacter isolates belong to the species R. radiotolerans and R. xylanophilus. We also show for the first time that the strains of R. xylanophilus and other strains of R. radiotolerans are extremely gamma radiation resistant.

The measurement of expressed emotion in relationships between staff and service users: the use of short speech samples

OBJECTIVES

Research on expressed emotion (EE) has demonstrated a remarkable consistency across cultures and over time; the psychosocial climate in relationships is important in determining the course of problems in mental health. The rating of EE might be described as the least accessible aspect of this literature to those who have not undertaken a training course. The purpose of this study was twofold: first, to obtain EE ratings for staff-patient relationships via interview and speech sample methods, in order to estimate the validity of the shorter method (the Five-Minute-Speech-Sample, FMSS); second, to examine the generalizability of the FMSS rating method to raters who were not previously trained to rate EE.

DESIGN AND METHOD

Staff (N = 15) working in a day hospital service for people with enduring mental health problems were interviewed about their work with at least one patient (N = 32), and also asked to provide an FMSS on each relationship. Ratings of FMSS-EE were subsequently compared with the Camberwell Family Interview-EE ratings. Following an hour-long training period, the FMSS-EE ratings of five postgraduate students were then compared with those of a criterion rater.

RESULTS

Correspondence between the two measures of EE was found to be good, with overall agreement achieved in 89.7% of cases. Raters with very limited training in the concept and rating of EE were accurate in identifying the overall rating of the relationship in question, but less accurate in identifying specific critical comments.

CONCLUSION

The FMSS technique can be used reliably to identify negative relationships even by raters given very limited training. Clinical and research applications are suggested.

Artefact on MRA following aneurysm clipping: an in vitro study and prospective comparison with conventional angiography

Using both an experimental model and clinical cases, we looked at the artefact produced by Aesculap titanium-alloy aneurysm clips on MRA. Experimentally, the volume affected by artefact was 50 % less when the clip was imaged lying parallel to the main ferromagnetic field than when lying perpendicular to it. Clinically, MRA was prospectively compared with digital subtraction angiography (DSA) in nine patients who had undergone aneurysm clipping. One patient with a non-diagnostic MRA due to movement artefact was excluded. In all other cases there was an area of signal loss surrounding the clips, obscuring the immediately adjacent vessel segments. There was good demonstration of the adjacent bifurcations in five cases and the contralateral circulation was seen well in all patients. In three cases in which the adjacent bifurcations were not seen, considerable vasospasm was suggested by MRA and confirmed with DSA. In one patient an unclipped contralateral ophthalmic artery aneurysm was identified using both modalities. In this series there were no adverse events relating to clips in either static or time-varying magnetic fields.

Effects of radiation on a three-dimensional model of malignant glioma invasion

An experimental model of malignant glioma growth involving implantation of spheroids into a gel matrix of collagen type I has been developed. This model has been used to characterize changes in glioma cell invasion in response to single dose and fractionated radiation treatment. Suspensions of C6 astrocytoma cells were grown in spinner culture flasks to yield spheroids of varying size (300-1000 microm). Implantation of spheroids into a gel matrix of collagen type I was associated with measurable invasion of the surrounding gel by individual tumor cells. Changes in the distance of invasion in response to single dose and fractionated radiation were measured. Changes in apoptosis and proliferative indices in different regions of the spheroids in response to radiation were also assessed. In unirradiated gels, maximum depth of invasion, 1300-1750 microm, was achieved by 5 days after implantation. A radiation dose-dependent inhibition of invasion was noted and was most profound for larger spheroids. Fractionation of the radiation dose was associated with a partial recovery of invasion. Changes in apoptotic and proliferative indices in response to radiation depended on the region of the spheroid examined. Increases in apoptosis were noted for cells at the surface of the spheroid and invading cells while cells at the centre of the spheroid demonstrated virtually no increase in apoptosis. Likewise, a dose-dependent decrease in proliferative indices following radiation was noted among the invading cells and cells at the surface of the spheroid but not at the centre of the spheroid. We have described a model of malignant glioma invasion which possesses many of the qualities of in vivo malignant gliomas. Within this model, invasion appeared to be inhibited by radiation in a dose- and fractionation-dependent fashion. Measurement of apoptotic and cell proliferation indices favour a direct cytotoxic effect on the invading cells as the most likely mechanism for this phenomenon.

Quality control for functional magnetic resonance imaging using automated data analysis and Shewhart charting

A data acquisition and analysis protocol for quality control (QC) of functional magnetic resonance imaging studies is presented. Two sets of data are acquired, single-timepoint data for measurement of signal-to-ghost and signal-to-noise ratios, and multiple-timepoint data for measurement of short-term drift. Since manual data analysis can be time consuming and an impediment to regular QC, an automated data processing scheme is presented. The use of automated Shewhart charting is proposed to identify significant changes in each parameter over the long term. The protocol has successfully identified system faults and deteriorations undetected by conventional QC.

Systemic sclerosis (scleroderma) in two iron ore mines

Six males with systemic sclerosis were observed in the work forces of two iron ore mines. The usual spectrum of clinical features encountered in systemic sclerosis patients were present. Histologic examination of pulmonary tissue was performed on three of the cases and showed features of both silicosis and scleroderma but to different degrees and stages of development. Exposure to high levels of silica-containing dusts had occurred in all six cases.

Widespread chromosomal abnormalities in high-grade ductal carcinoma in situ of the breast. Comparative genomic hybridization study of pure high-grade DCIS

For a variety of technical reasons it is rarely possible to study cytogenetic abnormalities in ductal carcinoma in situ (DCIS) using traditional techniques. However, by combining molecular biology and computerized image analysis it is possible to carry out cytogenetic analyses on formalin-fixed, paraffin-embedded tissue, using comparative genomic hybridization (CGH). The purpose of this study was to identify the prevalence of chromosomal amplifications and deletions in high-grade DCIS and to look specifically for unique or consistent abnormalities in this pre-invasive cancer. Twenty-three cases of asymptomatic, non-palpable, screen-detected, high-grade DCIS were examined using CGH on tumour cells obtained from histology slides. All cases showed chromosomal abnormalities. A wide variety of amplifications and deletions were spread across the genome. The most frequent changes were gains of chromosomes 17 (13 of 23), 16p (13 of 23), and 20q (9 of 23) and amplifications of 11q13 (22 of 23), 12q 24.1-24.2 (12 of 23), 6p21.3 (11 of 23), and 1q31-qter (6 of 23). The most frequent deletions were on 13q 21.3-q33 (7 of 23), 9p21 (4 of 23), and 6q16.1 (4 of 23). These findings indicate that high-grade DCIS is, from a cytogenetic viewpoint, an advanced lesion. There was no absolutely consistent finding in every case, but amplification of 11q13 was found in 22 of the 23 cases. The precise significance of this is unknown at present. This region of chromosome 11q harbours a number of known oncogenes, including cyclin D1 andINT2. It is likely that many of these findings are the result of accumulated chromosomal abnormalities, reflecting an unstable genome in established malignancy.

3-nitroadipate, a metabolic intermediate for mineralization of 2, 4-dinitrophenol by a new strain of a Rhodococcus species

The bacterial strain RB1 has been isolated by enrichment cultivation with 2,4-dinitrophenol as the sole nitrogen, carbon, and energy source and characterized, on the basis of 16S rRNA gene sequence comparison, as a Rhodococcus species closely related to Rhodococcus opacus. Rhodococcus sp. strain RB1 degrades 2,4-dinitrophenol, releasing the two nitro groups from the compound as nitrite. The release of nitro groups from 2,4-dinitrophenol occurs in two steps. First, the 2-nitro group is removed as nitrite, with the production of an aliphatic nitro compound identified by 1H nuclear magnetic resonance and mass spectrometry as 3-nitroadipate. Then, this metabolic derivative is further metabolized, releasing its nitro group as nitrite. Full nitrite assimilation upon reduction to ammonia requires that an additional carbon source be supplied to the medium.

A comparison of calcaneus ultrasound and dual X-ray absorptiometry in healthy North American youths and young adults

Quantitative ultrasound is the newest noninvasive method to be accepted for assessing bone mineral in adults. Heel ultrasound measurements correlate with bone density measurements by dual X-ray absorptiometry (DXA) and predict fracture risk in adults. Far less is known about the value of calcaneus ultrasound (CUS) in children. We determine spine, femoral neck, and whole-body bone mineral by DXA and heel bone mass by CUS in 125 youths (69 females, 56 males) ages 9-25 yr. CUS and DXA measurements of bone mass increased with age and pubertal development during adolescence in a parallel fashion. Among females, Tanner stage was a stronger predictor than age for all CUS and DXA measurements, and among males, pubertal stage was a stronger predictor for spine bone mineral apparent density (BMAD) and femoral bone mineral density (BMD). CUS measurements correlated moderately well with DXA measurements of the spine, femoral neck, and whole-body BMD and spine BMAD (r = 0.23-0.58, p < 0. 008). CUS warrants further study as a tool for assessing bone mineral acquisition in children.

Quantitative detection of Sphingomonas chlorophenolica in soil via competitive polymerase chain reaction

The 16S ribosomal RNA gene sequence of the pentachlorophenol degrader Sphingomonas chlorophenolica strain RA2 was used to generate specific polymerase chain reaction (PCR) primers for the detection of this strain in soil, whereas a region internal to the two primers was used to provide an S. chlorophenolica strain RA2-specific oligonucleotide probe. The PCR detection system resulted in a 727 bp product detectable via gel electrophoresis and hybridization. It was specific for strain RA2 and its close relative, S. chlorophenolica ATCC 39723, as evidenced by PCR amplifications of a range of bacterial genomic DNAs. Tests of total microbial community DNA obtained from five uninoculated and two RA2-inoculated soils confirmed this specificity for introduced S. chlorophenolica RA2. Strain RA2 could be detected in soil down to a level of 10(3) cfu g-1 soil. Two strategies were followed to generate internal standard DNA for competitive PCR. First, a 479 bp MIMICS fragment was obtained based on a previously constructed gene cassette; however, this standard did not reliably quantify RA2 targets. Low stringency PCR performed with a range of bacterial genomic DNAs resulted in the generation of an amplicon with a Paenibacillus azotofixans strain that was slightly smaller than the RA2-derived product. Both products were easily separable via conventional gel electrophoresis. The use of this competitor in a threefold dilution scheme applied to the target DNA allowed for the quantitative detection of RA2-specific target DNA molecules from pure culture and from soil. The fate of strain RA2 in pentachlorophenol-contaminated soil was described using this competitive PCR approach, and the organism was shown to persist at two inoculum levels over prolonged periods of time.

Gastrostomy buttons for nutritional support on chronic dialysis

RATIONALE

Nutritional support for children on chronic dialysis often involves the use of nasogastric tubes or gastrostomy feeding. We report our experience using gastrostomy buttons (GB) over a 6.6-year period to document their success/failure, the feeding regimens employed and the impact on growth.

DESIGN

In 339 patient months of prospective observation, 22 children (14 male) commenced gastrostomy feeding at a median age of 2.3 years (range 0.2-10.3 years). Sixteen patients had an initial gastrostomy catheter inserted at the same time as a chronic dialysis catheter. Eighteen patients were established on continuous cycling peritoneal dialysis (CCPD) and four on haemodialysis (HD).

RESULTS

The mean duration of combined gastrostomy feeding and chronic dialysis was 14.5 months (range 2.4 56 months). In 20 of the children followed for 6 months on combined GB feeding and dialysis, the mean protein and energy intakes were 2.5 g/kg bodyweight/day (range 1.7-3.4 g) and 108 kcal/kg bodyweight/day (range 72-129 kcal). The mean energy intake achieved was 116% (range 98-155%) of the estimated average requirement (EAR) for energy. The mean percentage of total energy and protein intakes delivered via the GB during the study period was 61% (33-95%) and 61% (23-98%) respectively. Mean height standard deviation score (SDS) was -2.22 prior to GB feeding and -2.06 at the end of the study period (P = 0.005) and mean weight SDS was -2.22 and -1.16 (P = 0.001) respectively. The mean life of the GB was 7.7 months (range 2.6 14 months) with most button changes due to leakage problems. Two episodes of peritonitis were attributable to the GB with one requiring peritoneal dialysis catheter removal due to candida infection. The GB was removed at a mean of 2.8 months (range 0.8-8.3 months) after renal transplantation in 13 children.

CONCLUSION

The gastrostomy button provides a valuable and aesthetically appealing route for nutritional support with few complications.

Evidence for genetic linkage to alcohol dependence on chromosomes 4 and 11 from an autosome-wide scan in an American Indian population

To identify specific genes affecting vulnerability or resistance, we performed a whole-autosomal genome scan for genetic linkage to alcohol dependence in a Southwestern American Indian tribe. Genotypes at 517 autosomal microsatellite loci and clinical evaluations were available for 152 subjects belonging to extended pedigrees and forming 172 sib-pairs. Highly suggestive evidence for linkage emerged for two genomic regions using two- and multipoint sib-pair regression methods; both regions harbored neurogenetic candidate genes. The best evidence is seen with D11S1984 (nominal P = 0.00007, lod approximately equal to 3.1) on chromosome 11p, in close proximity to the DRD4 dopamine receptor and tyrosine hydroxylase (TH) genes. Good evidence is seen with D4S3242 (nominal P = 0.0002, lod approximately equal to 2.8) on chromosome 4p, near the beta1 GABA receptor gene. Interestingly, three loci in the alcohol dehydrogenase gene cluster on chromosome 4q showed evidence for linkage with two-point analyses, but not multipoint analysis.