Effects of the acyl chain composition of phosphatidylcholines on the stability of freeze-dried small liposomes in the presence of maltose

The effects of the acyl chain composition of phosphatidylcholines (PCs) on the stability of small unilamellar vesicles during freeze-drying and rehydration in the presence of maltose were studied by monitoring the retention of a trapped marker, calcein, in the internal liposome compartment. In dipalmitoyl PC, beta-oleoyl-gamma-palmitoyl-PC and egg yolk PC liposomes, good or fair retentions (>50%) were observed in the presence of maltose, but maltose was ineffective in preserving retention in the dioleoyl PC (DOPC) liposomes (<10%). The extremely low retention in the DOPC liposome was ascribed to neither a formation of the inverted hexagonal phase of the liposomal membrane nor the fusion/aggregation of the liposomes in the drying-rehydration process. Differential scanning calorimetry measurements suggested that interactions of maltose with PC headgroups were essential to stabilizing the dry liposomes. These interactions were significant in the saturated or mixed chain liposomes but were markedly reduced in the DOPC liposomes.

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.

Resonance energy transfer study of peptide-lipid complexes

Resonance energy transfer involving tryptophan as a donor and anthrylvinyl-labeled phosphatidylcholine (AV-PC), 3-methoxybenzanthrone (MBA) and 8-anilino-1-naphthalene sulfonic acid (ANS) as acceptors has been examined to obtain information on the structure of peptide-lipid systems consisting of 18A or Ac-18A-NH(2) peptides and large unilamellar phosphatidylcholine vesicles. The lower and upper limits for the tryptophan distance from the bilayer midplane have been assessed in terms of the models of energy transfer in two-dimensional systems, taking into account orientational effects. Evidence for the existence of preferential orientations of Ac-18A-NH(2) with respect to the lipid-water interface has been obtained.

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.

Endovascular trapping of giant serpentine aneurysms by using Guglielmi detachable coils: successful reduction of mass effect. Report of two cases

Giant serpentine aneurysms (GSAs) are defined as partially thrombosed giant aneurysms with persistent serpentine vascular channels. Surgical management of these rare lesions is difficult because of their large size, complex structure, and unique hemodynamics. The authors report two cases of patients harboring GSAs with mass effect, which were managed effectively with endovascular treatment. The first patient was a 48-year-old man who presented with left homonymous hemianopsia caused by a GSA involving the terminal portion of the right internal carotid artery. The second patient, a 10-year-old boy, presented with tetraparesis from compression of the cervicomedullary junction by a GSA of the right vertebral artery. In each case, after confirming collateral flow by temporarily occluding the proximal artery, the aneurysm was trapped by placement of Guglielmi detachable coils at the sites at which the serpentine channels entered and exited the aneurysm. The midportion of each channel was isolated completely without packing, to maximize resorption of the devascularized mass. Mass effect and clinical symptoms rapidly improved in both cases, with no associated morbidity. We recommend endovascular trapping as a safe and effective therapeutic option for GSAs.

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.

[Primary renal non-Hodgkin's lymphoma presenting as immune thrombocytopenia]

A 25-year-old man was admitted to our hospital because of hematuria, anemia and thrombocytopenia. Laboratory examinations revealed an increased number of bone marrow megakaryocytes and an increased level of platelet-associated immunoglobulin G, suggesting immune thrombocytopenia. Computed tomography of the abdomen showed enlargement of the bilateral kidneys with multiple low-density areas, although neither lymphadenopathy nor hepatosplenomegaly was evident. After amelioration of the thrombocytopenia by prednisolone therapy, open renal biopsy was performed and a diagnosis of diffuse large B-cell non-Hodgkin's lymphoma was made. The patient achieved complete remission after CHOP therapy. This was thought to be a rare case of primary renal non-Hodgkin's lymphoma initially presenting as immune thrombocytopenia, which was treated successfully by chemotherapy.

Modulation of apolipoprotein E-mediated plasma clearance and cell uptake of emulsion particles by cholesteryl ester

Cholesteryl ester, along with triglyceride (TG), is the major core component of plasma lipoproteins. We investigated the effect of core composition on the physical state and metabolic behavior of lipid emulsions, as model particles of lipoproteins. Fluorescence studies using 1,6-diphenylhexatriene analogs showed that although cholesteryl oleate (CO) significantly decreased core mobility, the surface rigidity of phosphatidylcholine (PC) monolayers was independent of core composition. When intravenously injected into rats, the increased amount of core CO tended to retard TG emulsion removal from plasma, and the initial clearance rate was correlated with the amount of apolipoprotein E (apoE) bound from plasma. In addition, PC liposomes with a similar emulsion particle size showed negligible binding of apoE and were cleared at a slower rate compared to all emulsions. Furthermore, the effect of CO on the binding behavior of apoE to the emulsion surface and the emulsion uptake by hepatocytes was assessed in vitro. Replacing core TG with CO was found to decrease the apoE binding capacity to emulsions markedly without changing the binding affinity and thereby to reduce the cell uptake of emulsion particles by HepG2 cells. These results indicate that the physical state of core lipids, which can be modulated by CO content, plays a role in emulsion metabolism through the alteration in apoE binding.

Efficient shoot regeneration from hairy roots of Antirrhinum majus L. transformed by the rol type MAT vector system

 Eleven independent GUS-positive hairy roots were induced by co-cultivation of leaf explants of Antirrhinum majus L. with Agrobacterium tumefaciens strain GV2260 containing the rol type MAT vector pNPI702. The MAT vector pNPI702 possesses a GUS gene under the 35 S promoter and a removal element in which the 7.6-kb DNA fragments containing the rolA, B, C and D genes and recombinase gene with a 35 S promoter are located between two directly oriented recombination site sequences. A total of 326 adventitious shoots regenerated from 11 independent hairy root lines cultured on 1/2MS medium without plant growth regulators at 25  °C under a 16/8 h (day/night) photoperiod after 8 weeks of stock-culture of hairy roots and 4 weeks of culture of the green segments of hairy roots. Regenerated plants showed either a normal or dwarf morphology. GUS activity was observed in the hairy roots and regenerated shoots. The presence of the GUS gene in the regenerated, morphologically normal plants was confirmed by PCR analysis.

Adjuvant action of Escherichia coli enterotoxin for delayed-type hypersensitivity to Oka vaccine virus on pernasal co-administration in mice

The usefulness of a mutant of Escherichia coli enterotoxin for the induction of cellular immunity to varicella-zoster virus as a mucosal adjuvant is assessed in mice. When a commercially available live varicella vaccine (the Oka strain) and toxin were once administered simultaneously via the nasal route, delayed-type hypersensitivity to Oka vaccine virus was significantly induced and detected by footpad test in mice. Moreover, when spleen cells from mice immunized with the vaccine and toxin were re-stimulated with live vaccine in vitro, they showed more thymidine uptake and produced more IL-2 than those from mice immunized with the vaccine alone. These results suggest that mutant enterotoxin has adjuvant action to induce a specific delayed-type hypersensitivity to Oka vaccine virus on nasal co-administration with live vaccine virus.

Transformation of Antirrhinum majus L. by a rol-type multi-auto-transformation (MAT) vector system

A total of 11 independent beta-glucuronidase (GUS) positive hairy roots were induced following co-cultivation of leaf explants of Antirrhinum majus L. with Agrobacterium tumefaciens strain GV2260 containing rol-type multi-auto-transformation (MAT) vector pNPI702. A total of 326 adventitious shoots were regenerated from the hairy root lines on 1/2 MS medium without plant growth regulators at 25 degrees C under a 16 h/day photoperiod condition 4 months after infection of the A. tumefaciens GV2260. The absence of the rol genes in five plants was verified by polymerase chain reaction (PCR) and Southern blot analysis. Acclimatized transformants exhibited normal phenotypes in height and in the morphology of leaves and flowers. Furthermore, the GUS gene was strongly expressed in the leaves, inflorescence of the transformed plant, and the progeny. This result demonstrates that the rol-type MAT vector can be used to study gene functions controlling the morphogenesis of Antirrhinum majus plants.

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.

Liver involvement in hereditary haemorrhagic telangiectasia: assessment with 99Tcm-phytate radionuclide angiography and 123I-IMP transrectal portal scintigraphy

Abnormal hepatic haemodynamics and function in a 43-year-old woman with hereditary haemorrhagic telangiectasia (HHT) were evaluated using 99Tcm-phytate angiography and iodine-123-iodoamphetamine transrectal portal scintigraphy. Radionuclide angiography demonstrated hyperdynamic perfusion of the liver owing to intrahepatic arteriovenous fistulae (AVF), entry of tracer into the systemic circulation through intrahepatic portosystemic shunts and an increase in recirculating blood flow caused by these vascular disorders. Heterogeneous distribution of tracer also suggested the presence of chronic hepatic injury. Transrectal portal scintigraphy showed large portosystemic shunts. Other imaging techniques confirmed the presence of the AVF but failed to identify the portosystemic shunts. Non-invasive radionuclide studies are helpful in the evaluation of hepatic involvement of HHT.

Radiographic diagnosis of early colorectal cancer, with special reference to the superficial type of invasive carcinoma

The possibility of radiographically diagnosing carcinoma with submucosal involvement (invasive carcinoma) is discussed based on 119 invasive carcinomas of the large bowel that had been treated surgically and colonoscopically over a period of 9 years (1989-1997) at the Cancer Institute Hospital in Tokyo. Of these lesions, 38 were superficial-type invasive carcinoma, accounting for 31.9% (38/119) of all invasive colorectal carcinomas, including 36 lesions (94.7%, 36/38) of types IIa and IIa + IIc and 2 lesions (5.3%, 2/38) of type IIc + IIa. No pure type IIc was seen. The radiographic images obtained were correlated with macroscopic findings and analyzed in terms of visualization of the lesion's contour, central depression, converging folds, and basal indentation. A definitive diagnosis of superficial invasive carcinoma can be made radiographically if a lesion measures 10 mm and reveals moderate to severe basal indentation in a complete or nearly complete profile radiographic image. Attention should be paid to the presence of superficial-type advanced carcinomas measuring 10 mm or less, which is not infrequently experienced in Japan. Polypoid invasive carcinoma can be definitively diagnosed in the same way with much more certainty than can the superficial type because few polypoid advanced carcinomas are less than 20 mm. The size and the radiographic sign of the basal indentation are the most important indicators for the diagnosis of invasive carcinoma.

[CD19-positive acute myeloblastic leukemia developed 12 years after the onset of hypereosinophilic syndrome]

We report a rare case of hypereosinophilic syndrome (HES) that developed to acute myeloblastic leukemia (AML). The patient, a 34-year-old man, presented with eosinophilia of unknown origin (white blood cells 38,200/microliter with 74% eosinophils) and pericardial effusion, and was diagnosed as having HES with a normal karyotype. He received four cycles of combination chemotherapy including cyclophosphamide, cytosine arabinoside and vindesine, and thereafter remained in remission. After 12 years, he was referred to our hospital because of fever and malaise. On admission, CBC showed white blood cells 3,000/microliter with 70% myeloblasts and 3% eosinophils. The bone marrow was hypercellular with 95% blasts, which were negative for myeloperoxidase (MPO) staining. Immunophenotype analysis revealed that the cells were positive for CD13, CD19, CD34, HLA-DR and cytoplasmic MPO. CD19-positive AML was diagnosed. Cytogenetic analysis showed 46, XY, t(6;21)(q13;q22), add(7)(q11) in 19 of 20 metaphase spreads. Rearrangement of the AML1 gene at 21q22 and fusion of the BCR/ABL gene could not be detected by fluorescence in situ hybridization analysis. The patient received combination chemotherapy and achieved a complete remission. Chromosome aberrations involving 7q as well as 21q22 suggested that the initial chemotherapy for HES might have been implicated in the pathogenesis of acute leukemia in this case.

Inhibition of lipoprotein lipase activity by sphingomyelin: role of membrane surface structure

We have recently shown that sphingomyelin (SM) strongly inhibits lipoprotein lipase (LPL)-mediated lipolysis in monolayers and emulsion particles. To further evaluate how SM modulates LPL activity on the emulsion surface, the relationship between membrane surface structure and LPL activity was investigated. We measured fluorescence anisotropy of 1-palmitoyl-2-[3-(diphenylhexatrienyl)propionyl]-sn-3-phosphati dylcho line, probing surface acyl chain fluidity, and fluorescence lifetime of N-(5-dimethylaminonaphthalene-1-sulfonyl)dipalmitoylphosphatidylethan olamine in H(2)O and D(2)O buffer, assessing the degree of hydration in the head group region. The results revealed that incorporation of egg SM into triolein-egg phosphatidylcholine emulsions markedly increased acyl chain order and decreased head group hydration of the surface monolayers. In contrast, cholesterol was shown to increase head group hydration despite a strong increase in acyl chain order. The close correlation between the apparent K(m) values of LPL and the degree of head group hydration indicated that LPL interacts with the head group region rather than with the hydrophobic interior of the surface monolayers. However, apparent V(max) did not show a simple correlation with any surface structure, and the finding in which SM had no effect on apparent V(max) of medium-chain triglyceride emulsions suggested that the hydrophobic interaction between acyl chains of SM and triglyceride at the emulsion surface is important for determining the apparent V(max). These results showed conclusively that SM inhibits LPL activity mainly by changing the emulsion surface structure and not by a specific interaction between SM and LPL.

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.

Low-dose cytarabine and aclarubicin in combination with granulocyte colony-stimulating factor (CAG regimen) for previously treated patients with relapsed or primary resistant acute myelogenous leukemia (AML) and previously untreated elderly patients with AML, secondary AML, and refractory anemia with excess blasts in transformation

We used the CAG regimen (low-dose cytarabine [10 mg/m2 per 12 hours, days 1-14], aclarubicin [14 mg/m2 per day, days 1-4], and granulocyte colony-stimulating factor [200 micrograms/m2 per day, days 1-14]) for the treatment of patients with primary resistant acute myelogenous leukemia (AML) and previously untreated elderly patients with AML, secondary AML, and refractory anemia with excess blasts in transformation (RAEB-T) in addition to relapsed AML. Forty-three of 69 (62%) patients achieved complete remission (CR), including 29 of 35 (83%) patients with relapsed AML, 1 of 8 patients with primary resistant AML, 5 of 8 elderly patients with previously untreated AML, and 8 of 18 patients with previously untreated secondary AML or RAEB-T. Ten of 22 (45%) patients > or = 65 years old achieved CR. The patients who achieved CR received at least 1 course of modified CAG therapy as the first consolidation therapy, followed by various second consolidation and intensification therapies. The median disease-free survival and overall survival were 8 and 15 months, respectively, for relapsed AML; 11 and 8 months for the elderly patients; and 8 and 17 months for secondary AML and RAEB-T. Myelosuppression was mild to moderate, and other than fever, severe nonhematologic toxicity was rare. CAG as the induction therapy seems promising for the treatment of various categories of poor-prognosis AML.

Induction of apoptosis in lymphoid tissues of mice after intramuscular injection of enterotoxigenic Escherichia coli enterotoxin

Although it has been reported that intravenous injection of Escherichia coli enterotoxin induces atrophies of the thymus and spleen by necrosis, the toxin injected intramuscularly to mice induced atrophies of both tissues, which were associated with apoptosis of lymphocytes. Apoptosis predominantly occurred in the thymus and increased in a time-dependent manner up to 26 h and faint ladder band patterns of DNA were observed at 36 h. Although the high dose of toxin also induced in vitro apoptosis in cultured thymocytes, the toxin was not detected in the serum at levels sufficient to cause in vitro apoptosis after intramuscular administration. By flow cytometric analysis, CD4+ CD8+ double-positive T cell and CD45+ positive B cell numbers were found to be mainly decreased in thymus and spleen, respectively, of mice. These results suggest that the atrophies of thymus and spleen by intramuscular administration of the toxin to mice are due to apoptosis of CD4+ CD8+ double-positive T and CD45+ positive B cells, respectively, but the toxin does not reach these cells via the circulation. A different mechanism from that in vitro in cultured cells might be involved in the induction of apoptosis in vivo.

Coalescence of Lipid Emulsions in Floating and Freeze-Thawing Processes: Examination of the Coalescence Transition State Theory

Lipid emulsions, triacylglycerol droplets covered with single surface monolayers of phospholipid in aqueous medium, were prepared by high-pressure emulsification and successive ultracentrifugation. Egg yolk phosphatidylethanolamine did not stabilize triolein (TO) droplets in aqueous medium. Phosphatidylcholine (PC) of various long fatty acyl chains dispersed TO and tricaprylin (TC) well in aqueous medium as emulsion droplets of 110 nm. After ultracentrifugation, however, oil separation was observed in the floating creamy layer of TO/dioleoyl-PC emulsions. Dioleoyl-PC contains two bulky unsaturated fatty acyl chains, as well as oleoyl chains, and it has a lower spontaneous curvature than egg PC. Egg PC and dipalmitoyl-PC gave stably dispersed emulsion droplets of TO even after the freeze-thawing (F-T) procedure. On the other hand, TO/egg PC emulsion droplets containing cholesterol of 83 mol% PC and TC/egg PC emulsion droplets coalesced after the F-T procedure. Cholesterol and a medium chain triacylglycerol, TC, were distributed into the surface PC monolayers and occupied an appreciable fraction of the surface area. These neutral lipids have small polar groups and thus decrease the mean spontaneous curvature of surface lipids. The relationship between the droplet coalescence and the spontaneous curvature was discussed on the basis of the coalescence transition state theory recently developed by Kabalnov et al. in 1996. In addition, effects of maltose on the emulsion coalescence in the freeze state were briefly discussed. Copyright 1999 Academic Press.