The very early stages of the human B-cell differentiation pathway are poorly understood, primarily because of the lack of appropriate permanent cell lines. Epstein-Barr virus (EBV) is a putative human oncogenic virus which transforms human B cells in vitro into continuously proliferating cells. It has been believed that EBV transforms mature B cells, but recently, transformation of immature pre-B-cell lines has been reported, suggesting that EBV might also transform cells much earlier in the B-cell lineage. We report here the establishment of cell lines transformed by EBV at various stages of the B-cell differentiation pathway. Interestingly, two lines showed the complete absence of immunoglobulin synthesis and the lack of immunoglobulin gene rearrangement despite containing EBV genome and surface markers of B cells. Our results indicate that EBV can infect and transform cells of the B lymphocyte lineage even before immunoglobulin gene rearrangement.

Animals↗

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Molecular cloning of cDNA encoding human interleukin-2 receptor.

The human interleukin-2 (IL-2) receptor was purified by affinity chromatography using the anti-Tac monoclonal antibody, and its N-terminal amino acid sequence was determined. Complementary DNA clones were isolated and sequenced to reveal the primary structure of the IL-2 receptor precursor, which has 272 amino acid residues. The receptor is separated into two domains by a putative 19-residue transmembrane region. Two mRNAs (1.4 and 3.5 kilobases) hybridizing to the cDNA clone were found in human T cells bearing the IL-2 receptor. The cDNA directed synthesis of the IL-2 receptor in COS cells.

Amino Acid Sequence↗

PubMedDate not supplied

Microsatellite variation in Japanese and Asian horses and their phylogenetic relationship using a European horse outgroup.

The genetic relationships of seven Japanese and four mainland-Asian horse populations, as well as two European horse populations, were estimated using data for 20 microsatellite loci. Mongolian horses showed the highest average heterozygosities (0.75-0.77) in all populations. Phylogenetic analysis showed the existence of three distinct clusters supported by high bootstrap values: the European cluster (Anglo-Arab and thoroughbreds), the Hokkaido-Kiso cluster, and the Mongolian cluster. The relationships of these clusters were consistent with their geographical distributions. Basing our assumptions on the phylogenetic tree and the genetic variation of horse populations, we suggest that Japanese horses originated from Mongolian horses migrating through the Korean Peninsula. The genetic relationship of Japanese horses corresponded to their geographical distribution. Microsatellite polymorphism data were shown to be useful for estimating the genetic relationships between Japanese horses and Asian horses.

Alleles↗

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Evaluation of a new heparin bonding process in prolonged extracorporeal membrane oxygenation.

A novel heparin bonding method has been developed for in situ surface modification using ozone oxidation, and evaluated in vitro and in vivo during prolonged extracorporeal membrane oxygenation (ECMO) experiments. The ECMO system consisted of a Capiox hollow fiber membrane oxygenator (MO; Terumo Corp., Tokyo, Japan) with an integral heat exchanger, a Capiox centrifugal pump (CP), and an extracorporeal circuit. The blood contacting surfaces of the system were completely modified using the heparin bonding process, and evaluated in a chronic sheep model for extended period of time, ranging from 96 to 168 hr, under minimal systemic heparinization. The heparin bonded surface was able to maintain high levels of heparin bioactivity, and showed improved blood compatibility in in vitro epifluorescent video microscopy experiments by suppressing platelet adhesion/activation and complement activation. For the ECMO experiments, extracorporeal blood flow was maintained at 3 L/min and the activated clotting time was maintained at 150 sec. There was no significant change in the gas transfer capability or mean pressure drop across the MO over experimental times of up to 168 hr. Platelet count and other coagulation parameters remained stable within the physiologic range throughout the experiment. There were no detectable thrombi in the CP, tubing, or connectors in the test circuit. Local thrombus formation was noted in a stagnant area of the MO, although this did not interfere with its function or lead to any significant embolization. Based on these results, the heparin bonded ECMO system appears to be a safe and effective device for prolonged extracorporeal circulation under minimal systemic heparinization.

Animals↗

PubMedDate not supplied

Isolation of orthomyxoviruses from migrating and domestic ducks in northern Japan in 1976--1977.

Ortho- and parmyxoviruses were isolated at high frequencies from cloacal and tracheal samples of 334 domestic and 161 migrating ducks in Miyagi and Akita Prefectures, Japan, in the winter of 1976--77. Forty-four hemagglutinating agents were isolated from these ducks. The frequency of virus isolation was much higher from the cloacal samples (6.3%) than the tracheal samples (2.6%). However, no significant difference was found in the isolation ratio between the domestic (7.8%) and migrating (6.8%) ducks. Nine strains of the hemagglutinating agents were identified as influenza A viruses and confirmed to be in pure form by complement-fixation (CF) tests and from their polypeptide profiles. The antigenic characterization of the influenza A viruses revealed the presence of several subtypes; Hav5Nav-2-3, Hav6Neq2, Hav6N2, Hav7Neq2 and Hav7N2.

Animals↗

PubMedDate not supplied

Isolation of three different influenza A viruses from an individual after probable double infection with H3N2 and H1N1 viruses.

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Adolescent↗

PubMedDate not supplied

Cardiohemodynamic effect of a novel calcium antagonist, SD-3211, in the dog.

The cardiohemodynamic effects of SD-3211, a calcium antagonist possessing a unique structure, were studied in anesthetized open-chest dogs and in conscious dogs. SD-3211 (10-300 micrograms/kg, i.v.) increased coronary and vertebral artery blood flow dose-dependently while lowering blood pressure, indicating a vasodilatation of these arteries. SD-3211 caused a significant increase in heart rate at 10-100 micrograms/kg, but a significant decrease at 300 micrograms/kg. Left ventricular dp dtmax was dose-dependently decreased at the dose range examined, and the change was significant at 300 micrograms/kg. When compared with the cardiohemodynamic effects of diltiazem (10 300 micrograms/kg, i.v.) and nicardipine (1-30 micrograms/kg, i.v.), the selectivity of SD-3211 with regard to vasodilatation as compared to cardiac depression, manifested by a reduction in heart rate and myocardial contractility, was greater than that of diltiazem, but less than that of nicardipine. Furthermore, a comparative study of the effects of orally administered SD-3211 and diltiazem on blood pressure and atrioventricular conduction in conscious, normotensive dogs, demonstrated that SD-3211 had a more potent and long-lasting hypotensive effect, but a much weaker effect on atrioventricular conduction prolongation than diltiazem. Thus, these in vivo cardiohemodynamic studies show that SD-3211 possesses a tissue-selectivity for vasculature, respectively cardiac tissues, which is intermediate between diltiazem and nicardipine.

Anesthesia↗