Abstract P2-01-31: Validation of novel diagnostic kits using the semi-dry dot-blot method for detecting metastatic lymph nodes in breast cancer; distinguishing macrometastases and micrometastases

Background: The semi-dry dot-blot (SDB) method is a diagnostic procedure for detecting lymph node (LN) metastases. Metastases are confirmed by the presence of cytokeratin (CK) in lavage fluid of sectioned LNs that contain anti-pancytokeratin antibody, based on the theory that epithelial components such as CK are not found in normal LNs. We evaluated two novel SDB kits that use the newly developed anti-CK19 antibody for diagnosing LN metastases in breast cancer.

Methods: We obtained 159 LNs dissected from 93 breast cancer patients from July 2013 to December 2015 at Nagasaki University Hospital, including 38 dissected axillary LNs and 121 sentinel LNs, sliced at 2-mm intervals and washed with phosphate-buffered saline. The suspended cells in the lavage fluid of sliced LNs were centrifuged and lysed to extract protein. This extracted protein was used with a low-power and a high-power kit to diagnose LN metastasis. The washed LNs were blindly diagnosed by pathologists using hematoxylin and eosin (H&E) stain. Diagnoses based on the kit were compared with their H&E counterparts.

Results: Of the 159 LNs, 68 were assessed as positive and 91 as negative by permanent pathological examination with H&E. Sensitivity, specificity, and accuracy of the low-power kit for detecting LN metastases was 83.8%, 100%, and 93.1%, respectively. In 11 false-negative cases, there were nine micrometastases, producing a sensitivity of 96.4% for detecting macrometastases. Sensitivity, specificity, and accuracy of the high-power kit for detecting LN metastases was 92.6%, 92.3%, and 92.5%, respectively. Combining the low- and high-power kit results, sensitivity, specificity and accuracy for distinguishing macrometastases from micrometastases was 94.5%, 95.2%, and 95.0%, respectively. Diagnosis was achieved in approximately 20 min using the kits, at a cost of less than 25 USD.

Conclusions: The kits in our study were accurate, quick, and cost-effective in diagnosing LN metastases without the loss of LN tissue. The kits' ability to distinguish macrometastases from micrometastases was excellent, which is important, clinically.

Citation Format: Otsubo R, Hirakawa H, Oikawa M, Inamasu E, Baba M, Matsumoto M, Yano H, Kinoshita N, Abe K, Fukuoka J, Nagayasu T. Validation of novel diagnostic kits using the semi-dry dot-blot method for detecting metastatic lymph nodes in breast cancer; distinguishing macrometastases and micrometastases [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-31.

Abstract P4-21-03: A randomized phase II study of Ki-67 response-guided preoperative chemotherapy for HER2-positive breast cancer

As for the HER2-positive breast cancer, there are many cases to be effective for neoadjuvant chemotherapy in comparison with other intrinsic subtypes. However, pCR is not provided by neoadjuvant chemotherapy in all cases. [Aim] This study evaluated the effectiveness of a therapeutic strategy that switches chemotherapy, based on Ki-67 tumor expression after initial therapy, relative to that of standard chemotherapy in patients with HER2-positive breast cancer. [patients and methods] Patients were randomly assigned to the control arm or the Ki-67 response-guided arm (Ki-67 arm). Primary tumor biopsies were obtained before treatment, and after three once-weekly doses of paclitaxel and trastuzumab to assess the interim Ki-67 index. In the control arm, paclitaxel and trastuzumab was continued for a total of 12 doses, regardless of the interim Ki-67 index. In the Ki-67 arm, subsequent treatment was based on the interim Ki-67 index. Early Ki-67 responders continued to received paclitaxel plus trastuzumab for a total of 12 doses, while early Ki-67 non-responders were switched to epirubicin plus cyclophosphamide every 3 weeks for three cycles with once-weekly trastuzumab for a total of 12 doses. The primary endpoint was the pathological complete response (pCR) rate. [Results] When 237 patients were enrolled, an interim analysis was conducted in 200 patients. There was almost linear correlation between the Ki-67 reduction rate at interim assessment and the pCR rate. The pCR rate in Ki-67 early non-responders in the Ki-67 arm (23.6%; 95% CI, 12.4 to 34.9) was inferior to that in the control arm (44.1%; 31.4 to 56.7; p=0.025). A strong correlation was not found between the Ki-67 reduction rate and the clinical response rate (Spearman's correlation coefficient 0.22).

pCR rate among Ki-67 early non-responders and responders TotalpCR nn%95%CIKi-67 early non responderControl arm59264431.4-56.7 Ki-67 response guided arm55132312.4-34.9Ki-67 early responderControl arm21104726.3-69.0 Ki-67 response guided arm2084018.5-61.5

Conclusions: The pCR rate in the Ki-67 arm was inferior to that in the control arm. A therapeutic strategy that switches chemotherapy, based on Ki-67 tumor expression after initial therapy, was not effective. The standard chemotherapy protocol remains as the recommended strategy for patients with HER2-positive breast cancer.

Citation Format: Takahashi M, Nishiyama Y, Hara F, Naito Y, Baba M, Sasaki M, Sato M, Watanabe K, Uemura Y, Yamaguchi T, Mukai H. A randomized phase II study of Ki-67 response-guided preoperative chemotherapy for HER2-positive breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-03.

Patient-specific glenoid guides provide accuracy and reproducibility in total shoulder arthroplasty

AIMS

Patient-specific glenoid guides (PSGs) claim an improvement in accuracy and reproducibility of the positioning of components in total shoulder arthroplasty (TSA). The results have not yet been confirmed in a prospective clinical trial. Our aim was to assess whether the use of PSGs in patients with osteoarthritis of the shoulder would allow accurate and reliable implantation of the glenoid component.

PATIENTS AND METHODS

A total of 17 patients (three men and 14 women) with a mean age of 71 years (53 to 81) awaiting TSA were enrolled in the study. Pre- and post-operative version and inclination of the glenoid were measured on CT scans, using 3D planning automatic software. During surgery, a congruent 3D-printed PSG was applied onto the glenoid surface, thus determining the entry point and orientation of the central guide wire used for reaming the glenoid and the introduction of the component. Manual segmentation was performed on post-operative CT scans to compare the planned and the actual position of the entry point (mm) and orientation of the component (°).

RESULTS

The mean error in the accuracy of the entry point was -0.1 mm (standard deviation (sd) 1.4) in the horizontal plane, and 0.8 mm (sd 1.3) in the vertical plane. The mean error in the orientation of the glenoid component was 3.4° (sd 5.1°) for version and 1.8° (sd 5.3°) for inclination.

CONCLUSION

Pre-operative planning with automatic software and the use of PSGs provides accurate and reproducible positioning and orientation of the glenoid component in anatomical TSA. Cite this article: Bone Joint J 2016;98-B:1080-5.

Allosteric Inhibitors against HIV-1 Reverse Transcriptase: Design and Synthesis of MKC-442 Analogues Having an Ω-Functionalized Acyclic Structure

Based on X-ray crystallographic analysis of MKC-442/human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT) complex, analogues in which the N1-substituent is replaced with ω-functionalized alkyl groups were designed to improve the affinity for the enzyme. Synthesis of these compounds was carried out starting from MKC-442 by a sequence of reactions (N3-protection, removal of N1-ethoxymethyl group, alkylation, and N3-deprotection). The compounds were evaluated for anti-HIV activity. Structure–activity relationships are discussed in terms of the possible interaction with the enzyme.

Activation cross sections of proton and deuteron induced nuclear reactions on holmium and erbium, related to the production of (161)Er and (160)Er medical isotopes

Experimental excitation functions for long-lived products in proton induced reactions were measured with the activation method in the 37-65MeV energy range on natural holmium. Stacked foil irradiation technique and high resolution gamma spectrometry were used in order to measure cross-section data for the production of (161)Er, (160)Er and (1)(59,157)Dy. For comparison of the production routes of medically related (161)Er and (160)Er radioisotopes new experimental cross section data were deduced for the (162)Er(p,x)(161,160)Er and (162)Er(d,x)(161,160)Er reactions by re-evaluating gamma-ray spectra from earlier measurements. No earlier data were found in the literature for these reactions. The experimental data are compared with results of TALYS theoretical code reported in TENDL-2015.

Theileria annulata seroprevalence among different cattle breeds in Rajshahi Division, Bangladesh

An epidemiological survey of Theileria annulata infection was undertaken in a cattle population in Rajshahi Division, Bangladesh. The local cattle breeds from the area (North Bengal Gray and Deshi) and crosses between the local breeds and Holstein cattle were predominantly screened. In total, 192 cattle serum samples were collected in two areas of Rajshahi Division, the Rajshahi District (n=147) and Natore District (n=45). The samples were screened with an enzyme-linked immunosorbent assay using T. annulata surface protein (TaSP) as the antigen. The seroprevalence was 80.0% (36/45) in Natore and 20.4% (30/147) in Rajshahi. A logistic regression analysis showed that the sampling location was significantly associated with seropositivity, whereas age, sex and breed were not. Although the logistic regression analysis did not show a linear dependence on age, we considered age-specific seroprevalence separately in the two districts. Seroprevalence did not differ significantly among age categories in the Natore District. In contrast, all the cattle <1 year old in the Rajshahi District were seronegative (11/11). Seroprevalence in the 1- and 2-year-old cattle was significantly lower in the Rajshahi District than in the Natore District. In the older age categories (3, 4 and >5 years), seroprevalence did not differ significantly between the Natore and Rajshahi Districts. These results suggest that the cattle in the Rajshahi District were sporadically exposed to T. annulata, whereas most cattle in the Natore District became infected during an early phase of life.

Naphthalenesulphonic Acid Derivatives as Potential anti-HIV-1 Agents. Chemistry, Biology and Molecular Modelling of Their Inhibition of Reverse Transcriptase

Activity against human immunodeficiency virus (HIV) in the naphthalenesulphonic acid series is most pronounced in the disulphonic acid series. In this class of compounds, N-acyl derivatives of 4-amino-5-hydroxy-2,7-naphthalenedisulphonic acid demonstrate significant anti-HIV activity at non-toxic doses. The most potent compounds in this group of agents are bis naphthalenedisulphonic acids. A bis derivative containing a decamethylene spacer demonstrated activity against HIV-1, HIV-2 giant cell formation and reverse transcriptase (RT). This compound also demonstrated an in vitro therapeutic index (ratio of 50% cytotoxic concentration to 50% inhibitory antiviral concentration) of 10.6. Molecular modelling analyses of this agent, suramin, and several suramin analogues were undertaken to explain the potent anti-HIV-1 RT activity. These studies were carried out using the molecular decomposition/recomposition strategy, conformational searching, energy minimization and molecular dynamics (MD) simulation. The bis naphthalenedisulphonic acid derivative compound 1, having a flexible decamethylene spacer, was shown to be able to mimic the helical twist of the B-DNA backbone as a low energy conformer state.

Sulphated Polymers are Potent and Selective Inhibitors of Various Enveloped Viruses, Including Herpes Simplex Virus, Cytomegalovirus, Vesicular Stomatitis Virus, Respiratory Syncytial Virus, and Toga-, Arena- and Retroviruses

The sulphated polymers, such as polyvinylalcohol sulphate (PVAS) and its co-polymer with acrylic acid (PAVAS), have proved to be potent inhibitors for herpes simplex virus, human cytomegalovirus, vesicular stomatitis virus, respiratory syncytial virus, Sindbis virus, Semliki Forest virus, Junin virus, Tacaribe virus, murine sarcoma virus and human immunodeficiency virus. They are not inhibitory to non-enveloped viruses, such as poliovirus and reovirus. The broad-spectrum antiviral effects of these compounds depend on their molecular weight and degree of sulphation. Pharmacokinetic studies in rabbits have indicated that after intravenous bolus injection the serum concentrations of these compounds decay biphasically, with an initial half-life of approximately 90–120 min.

Antiviral Activity of a Sulphated Polysaccharide Extracted from the Marine Pseudomonas and Marine Plant Dinoflagellata against Human Immunodeficiency Viruses and other Enveloped Viruses

A natural sulphated mucopolysaccharide (OKU40), extracted from a marine plant Dinoflagellata, and an artificial sulphated polysaccharide (OKU41), prepared from a marine Pseudomonas, displayed antiviral activities against several enveloped viruses. OKU40 and OKU41 were found to be homogenous in electrophoresis and sedimation velocity and had a molecular weight of 8.0 × 1065.0 × 105respectively. The sulphation rate of OKU40 and OKU41 was 8.9% and 5.4%, respectively. Each OKU40 and OKU41 inhibited the cytopathic effect of human immunodeficiency virus type 1 (HIV-1), type 2 (HIV-2) and zidovudineresistant HIV-1 in MT-4 cells at similar concentrations to those of dextran sulphate (molecular weight: 5000) (50% inhibitory concentrations: 0.86-1.95 μg mL−1), whereas these compounds did not affect the growth and viability of mock-infected MT-4 cells at concentrations up to 500 μg mL−1. These compounds proved inhibitory not only to HIV-1 and HIV-2 but also to other enveloped viruses, i.e. herpes simplex virus type 1, influenza virus A and B, respiratory syncytial virus and measles virus. OKU40 and OKU41 suppressed syncytium formation induced by cocultivation of MOLT-4/IIIb and MOLT-4 cells at concentrations higher than 20 μg mL−1. Although OKU41 inhibited the binding of HIV-1 to the host cells and the binding of anti-gp120 monoclonal antibody to HIV-1 gp120, OKU40 did not inhibit these bindings, suggesting that the mechanism of anti-HIV activity of OKU40 and OKU41 may be primarily due to the inhibition of virus-cell fusion and viral adsorption to the host cells, respectively. Furthermore, these compounds did not inhibit to the blood coagulation process at a concentration that was significantly inhibitory to HIV replication. The compounds appear to have an interesting potential as virucidal agents.

Inhibitory Effect of Pyridobenzoazoles on Orthomyxo-and Paramyxovirus Replication in vitro

Among thirteen newly synthesized pyridobenzoazole derivatives which have been examined for anti-myxovirus and antiherpesvirus activities, three benzimidazoles emerged as potent anti-orthomyxo- or paramyxovirus compounds. 4-Cyano-2-benzamide-1-oxo-1,5-dihydropyrido[1,2a]benzimidazole (CBO-PB) showed broad antiviral activities against paramyxo-and orthomyxoviruses with EC50 of 0.1–2.0 μg ml−1, and 2-cyano-1-amino derivatives of CBO-PB (CCI-PB) were inhibitory to paramyxoviruses at 1.4–8.5 (μg ml−1 by a plaque reduction method. The third compound, 2-ethoxycarbonyl derivatives of CCI-PB was inhibitory only to respiratory syncytial virus (RSV) at 15–28 μg ml−1. Selectivity indexes of these 3 compounds for RSV in HeLa cells were 60, 86, and >13, respectively. All three compounds inhibited syncytium formation of RSV and Parainfluenzavirus (PFLUV) type 3 at comparable concentrations with EC50 for plaque formation. They inhibited antigen production of RSV and PFLUV at the concentrations that were 4 to 20-fold higher than those needed for plaque reduction, but they did not inhibit adsorption of virus to cells at all. All three compounds inhibited the growth of RSV in HeLa cells at 4-fold higher concentrations than their EC50 for plaque reduction.

Potent and Selective Activity of Dextrin Sulphate against Human Immunodeficiency Virus Type 1 in vitro

Several dextrin sulphate derivatives were prepared and investigated for their activity against human immunodeficiency virus type 1 (HIV-1) in vitro. These compounds have proved to be potent and selective inhibitors of HIV-1. One of the compounds, termed FG-752 [molecular weight (MW) 3000], was the most active, and its 50% antiviral effective concentration was 2.1 μg ml−1 (0.7 μm) in MT-4 cells. No toxicity for the cells was observed at a concentration of 500 μg ml−1. The compounds were also inhibitory to HIV-1-induced giant cell (syncytium) formation. These results suggest that dextrin sulphate may be useful for the chemotherapy of HIV-1 infections.

In vitro Antimyxovirus and Anti-Human Immunodeficiency Virus Activities of Polyoxometalates

Polyoxometalates have been shown to inhibit the replication of retro-, toga-, paramyxo- and herpesviruses. The primary mechanism of the anti-human immunodeficiency virus type 1 (HIV-1) action of polyoxometalates seems to be inhibition of binding of virus to cells and inhibition of syncytium formation. Since myxoviruses and HIV-1 are known to interact with the cytoplasmic membrane by adsorption and penetration of virus and by fusion of infected and uninfected cells, 25 polyoxometalates were examined for anti-ortho-, anti-paramyxovirus and anti-HIV-1 activity in vitro. Of the 25 compounds evaluated, 24 showed antiviral effects against influenza virus A, 11 showed activity against respiratory syncytial virus, six showed activity against measles virus, and 23 were considered effective against HIV-1 at a lower concentration than that producing cytotoxicity. Four polyoxotungstates which had potent inhibitory effects were examined for inhibitory effects against additional ortho- and paramyxoviruses, and proved to have a broad spectrum of antimyxoviral activity. HS-058, the Keggin sandwich compound K10Fe4(H2O)2(PW9O34)2·nH2O, was inhibitory against influenza viruses A and B, respiratory syncytial virus, measles virus, and parainfluenza virus 2, with median effective concentrations of 1.4, 21.8, 7.4, 0.8 and 0.32 μ,M, respectively. However, HS-058 had no effect on parainfluenza virus 3 or mumps virus. The median cytotoxic concentration of HS-058 for Madin-Darby canine kidney (MDCK) and HEp-2 cells was more than 200 μM and that for HMV-2 and Vero cells was about 50 μM. When HS-058 was added at different times after influenza A and respiratory syncytial virus infection, it inhibited binding of the latter but not of the former to cells. However, at higher concentrations, HS-054 and HS-058 inhibited haemolysis of chick erythrocytes by influenza virus and syncytium formation involving respiratory syncytial virus-infected cells and uninfected cells. Four times the median effective antiviral concentration of HS-058 completely inhibited the growth of influenza virus A in MDCK cells when compound was added before virus adsorption. Furthermore, when HS-058 was added after virus adsorption, it inhibited the yield of virus in MDCK cells infected at low but not at high multiplicity of infection.

Antiviral Activities of Mizoribine and other Inosine Monophosphate Dehydrogenase Inhibitors against Several Ortho- and Paramyxoviruses

Mizoribine (4-carbamoyl-1-β-D-ribofuranosylimidazo-lelium-5-olate), EICAR (5-ethynyl-1-β-D-ribofuranosylimi-dazole-4-carboxamide), mycophenolic acid and ribavirin are antiviral agents targeted for inosine monophosphate (IMP) dehydrogenase. These compounds have been examined for their activities against orthomyxoviruses [influenza viruses (FluV)] and paramyxoviruses [parainfluenza viruses (PFIuV), mumps virus, measles virus (MLSV) and respiratory syncytial virus (RSV)] in vitro. Mizoribine was 1- to 9-fold more active than ribavirin against RSV, PFIuV and MLSV. EICAR and mycophenolic acid showed higher potency than mizoribine and ribavirin against all myxoviruses examined. None of the four compounds examined proved cytotoxic to stationary host cells (HeLa, Vero and MDCK) at a concentration of 200 μg ml−1 or more. On the other hand, EICAR and mycophenolic acid were toxic to rapidly growing cells at concentrations of 2.2-9 and 0.1-1.1 μg ml−1, respectively. Mizoribine and ribavirin showed cytotoxicity to the growing cells at higher concentrations (12-51 μg ml−1). The antiviral activities of mizoribine against FluV and RSV were reversed by 25-100 μm of each of guanosine and guanosine monophosphate (GMP). The antiviral activity of ribavirin against FluV was reversed by 25 μg of each of guanosine and GMP, while its activity against RSV was reversed by ≥ 100 μm of each of these compounds. Neither xanthosine nor xanthosine monophosphate (XMP) reversed the antiviral effects of mizoribine and ribavirin at concentrations of 300 μM. Concentrations 9 times higher than the median effective doses (EC50) of mizoribine and ribavirin inhibited the growth of RSV in HeLa cells as determined in an assay of infectious virus yield. Mizoribin should be further pursued as a candidate drug for the treatment of ortho- and paramyxovirus infections.

Isolation and Characterization of Human Immunodeficiency Virus Type-1 Mutants Resistant to the Non-Nucleotide Reverse Transcriptase Inhibitor MKC-442

MKC-442, 6-benzy 1-1-ethoxymethyl-5-isopropyIuraciI (l-EBU), is a potent and selective non-nucleoside inhibitor of human immunodeficiency virus type-1 (HIV-1) reverse transcriptase (RT). Nevirapine, another non-nucleoside RT inhibitor (NNRTI), is associated with rapid emergence of drug-resistant variants during in vitro passages of HIV-1. The emergence of resistant viruses to MKC-442 or nevirapine was examined in vitro. MT-4 cells infected with a clinical isolate (HE) of HIV-1 were cultivated in medium containing excess concentrations of these drugs, and the drug susceptibilities of the breakthrough viruses recovered from the medium were measured. Although nevirapine lost its antiviral activity after six passages, a delay in the emergence of fully resistant viruses was observed for MKC-442. Two resistant clones for each drug were isolated and nucleotide sequences within the RT region were analysed. An amino acid substitution at position 181 (Tyr to Cys) was found, with additional substitutions at positions 103 (Lys to Arg) and 108 (Val to lle) in the MKC-442-resistant viruses. These clones showed various susceptibilities to MKC-442, and cross-resistance to other NNRTIs but not to AZT. These results suggest that the major binding site of MKC-442 on the HIV-1 RT is the tyrosine residue common to these NNRTIs, and that drug resistance to NNRTIs is dependent on both the quality and the quantity of mutations within the HIV-1 RT gene.

Inhibition of HIV-1-Induced Cytopathogenicity, Syncytium Formation, and Virus-Cell Binding by Naphthalenedisulphonic Acids through Interaction with the Viral Envelope gp120 Glycoprotein

Bis-naphthalenedisulphonic acid derivatives with a biphenyl spacer, 4,4′-[4,4′-biphenyldiylbis(sulphonyl-amino)]bis(5-hydroxy-2,7-naphthalenedisulphonic acid) and 3,3′-[4,4′-biphenyldiylbis(sulphonyl-amino)]bis(1,5-naphthalenedisulphonic acid), have previously been reported as potent and selective inhibitors of human immunodeficiency virus type 1 (HIV-1) replication in cell culture. These compounds have also proved inhibitory to syncytium formation in cocultures of MOLT-4 cells with HIV-1-infected HUT-78 cells. They also inhibit the binding of HIV-1 virions to MT-4 cells as determined by a flow cytometric (FACS) method. Further studies on their mechanism of action by the FACS have revealed that the compounds inhibit the binding of anti-gp120 monoclonal antibody to the viral envelope glycoprotein gp120. Binding of OKT4A/Leu3a monoclonal antibody to the cellular CD4 receptor is not affected by the compounds. These results suggest that the anti-HIV-1 activity of the naphthalenedisulphonic acid derivatives can be attributed to inhibition of the gp120-CD4 interaction through binding of the compounds to the viral gp120 antigen.

Ingenol Derivatives are Highly Potent and Selective Inhibitors of HIV Replication in Vitro

Ingenol 3,5,20-triacetate has recently been identified as a highly potent and selective inhibitor of HIV replication in vitro. To evaluate the potential of ingenol derivatives as anti-HIV agents, several ingenol derivatives have been synthesized and investigated for their anti-HIV activities, structure-activity relationships, and possible mechanisms of action. Among the ingenol derivatives, 13-hydroxyingenol-3-(2,3-dimethylbutanoate)-13-dodecanoate (RD4-2138) proved to be a highly potent and selective inhibitor of HIV replication. Its 50% effective concentration for viral replication in MT-4 cells was 0.07-0.5 nM depending on viral strains, including HIV-2. This concentration was approximately 105-fold lower than its cytotoxic threshold. RD4-2138 was also inhibitory to the syncytium formation induced by cocultivation of Molt-4 cells with Molt-4/IIIB cells (Molt-4 cells chronically infected with HIV-1). Some correlation was observed with the ingenol derivatives between their inhibitory effects on HTLV-IIIB replication and surface CD4 expression in MT-4 cells, suggesting that the mechanism of inhibition is in part attributed to the inhibition of virus adsorption through down-regulation of CD4 molecules in the host cells. However, such correlation was not identified between the inhibition of HTLV-IIIB and the activation of protein kinase C. Thus, they might have a potential as effective anti-HIV agents when toxicity in vivo could be elucidated.

Activation cross sections of proton induced nuclear reactions on palladium up to 80MeV

Activation cross sections of proton induced nuclear reactions on palladium were measured up to 80MeV by using the stacked foil irradiation technique and gamma ray spectrometry. The beam intensity, the incident energy and the energy degradation were controlled by a method based on flux constancy via normalization to the excitation functions of monitor reactions measured in parallel. Excitation functions for direct and cumulative cross-sections were measured for the production of (104m,104g,105g,106m,110m)Ag, (100,101)Pd, (99m,99g,100,101m,101g,102m,102g,105)Rh and (103,97)Ru radioisotopes. The cross section data were compared with the theoretical predictions of TENDL-2014 and -2015 libraries. For practical applications thick target yields were derived from the measured excitation functions. Application in the field of medical radionuclide production is shortly discussed.

Removal of extracellular Toxoplasma gondii tachyzoites from suspended cell culture

Tachyzoites of Toxoplasma gondii, an obligate intracellular parasite, actively invade a broad spectrum of cell types. T. gondii infects leukocytes and spreads to distant organs such as the brain, lungs and muscles. However, the mechanism of T. gondii transmission from infected leukocytes to peripheral organs is unknown. To show the dynamics of infected leukocytes and intracellular parasites in vivo, previous studies have prepared T. gondii-infected leukocytes and injected them into circulation in experimental animals. However, when the infected leukocytes are prepared in vitro, some extracellular tachyzoites remain in the leukocyte cell culture because it is almost impossible to wash out these extracellular tachyzoites. These extracellular tachyzoites may distort experimental results. In this study, we report a method for removing extracellular tachyzoites from leukocyte culture suspension using antibody-conjugated magnetic beads. Using this method, extracellular tachyzoites in suspension cell culture can be effectively eliminated.

Excitation functions for (d,x) reactions on (133)Cs up to Ed=40MeV

In the frame of a systematic study of excitation functions of deuteron induced reactions the excitation functions of the (133)Cs(d,x)(133m,133mg,131mg)Ba,(134,)(132)Cs and (12)(9m)Xe nuclear reactions were measured up to 40MeV deuteron energies by using the stacked foil irradiation technique and γ-ray spectroscopy of activated samples. The results were compared with calculations performed with the theoretical nuclear reaction codes ALICE-IPPE-D, EMPIRE II-D and TALYS calculation listed in the TENDL-2014 library. A moderate agreement was obtained. Based on the integral yields deduced from our measured cross sections, production of (131)Cs via the (133)Cs(d,4n)(131)Ba→(131)Cs reaction and (133)Ba via (133)Cs(d,2n) reactions is discussed in comparison with other charged particle production routes.

The distribution pattern of α2,3- and α2,6-linked sialic acids affects host cell preference in Toxoplasma gondii

Tachyzoites of Toxoplasma gondii, an obligate intracellular parasite, actively invade almost all types of nucleated cells. However, T. gondii tachyzoites preferentially infect particular types of animal tissue cells. The mechanism underlying the host cell preference of T. gondii is not yet known. In this study, we found that enzymatic removal of α2,3- but not α2,6-linked sialic acids on the surface of Vero cells decreased T. gondii tachyzoite adhesion or invasion to the treated cells. Although Chinese hamster ovary (CHO) cells express only α2,3-linked sialic acid, a genetically modified CHO cell line constructed by transfection with the α2,6-sialiltransferase gene contains subpopulations with a variety of expression patterns of α2,3- and α2,6-linked sialic acids. When T. gondii tachyzoites were added to the modified CHO cells, the tachyzoites preferentially attached to cells belonging to a subpopulation of cells that highly expressed α2,3-linked sialic acids. Additionally, multiple regression analysis performed to analyse the relationship between the amount of α2,3-linked/α2,6-linked sialic acids and parasite-expressed fluorescence intensity suggested that more tachyzoites adhered to individual α2,3-linked sialic acid rich-cells than to α2,3-linked sialic acid-poor/null cells. The results of confocal laser microscopy confirmed this finding. These results indicate that the host cell preference of T. gondii was, at least partially, affected by the distribution pattern of α2,3-, but almost never α2,6-linked sialic acids on host cells.