899 research outputs found
SOMATIC CELL HYBRIDS BETWEEN MOUSE PERITONEAL MACROPHAGES AND SV40-TRANSFORMED HUMAN CELLS : I. Positive Control of the Transformed Phenotype by the Human Chromosome 7 Carrying the SV40 Genome
Fusion of mouse peritoneal macrophages with SV40-transformed human cells, deficient in hypoxanthine guanine phosphoribosyltransferase, resulted in the formation of transformed somatic cell hybrids which contained, without exception, the human chromosome 7 carrying the SV40 genome. It is postulated that the hybridization of mouse nondividing cells with human cancer cells could permit the identification of the human "oncogenic" chromosome(s) present in human cancer cells, since such chromosome(s) should be retained by the totality of the mouse-human hybrid cells
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Clonal analysis of a human antibody response. Quantitation of precursors of antibody-producing cells and generation and characterization of monoclonal IgM, IgG, and IgA to rabies virus.
We quantitated and characterized the changes in the human B cell repertoire, at the clonal level, before and after immunization with rabies virus. Moreover, we generated 10 monoclonal cell lines producing IgM, IgG, and IgA antibodies to the virus. We found that in healthy subjects, not previously exposed to the virus, nearly 2% of the circulating B lymphocytes were committed to the production of antibodies that bound the virus. These B cells expressed the surface CD5 molecule. The antibodies they produced were polyreactive IgM that displayed a relatively low affinity for the virus components (Kd, 1.0-2.4 x 10(-6) g/microliters). After immunization, different anti-virus (IgG and IgA) antibody-producing cells consistently appeared in the circulation and increased from less than 0.005% to greater than 10% of the total B cells committed to the production of IgG and IgA, respectively. Most of such B cells do not express CD5 and produce monoreactive antibodies of high affinity for rabies virus (Kd, 6.5 x 10(-9) to 1.2 x 10(-10) g/microliters). One of these IgG mAbs efficiently neutralized rabies virus in vitro and in vivo, as detailed elsewhere (Dietzschold, B., P. Casali, Y. Ueki, M. Gore, C. E. Rupprecht, A. L. Notkins, and H. Koprowski, manuscript submitted for publication). Hybridization experiments using probes specific for the different human V gene segment families revealed that cell precursors producing low affinity IgM binding to rabies virus utilized a restricted number of VH gene segments (i.e., only members of the VHIIIb subfamily), whereas cell precursors producing high affinity IgG and IgA to rabies virus utilized an assortment of different VH gene segments (i.e., members of the VHI, VHIII, VHIV, and VHVI families and VHIIIb subfamily). In conclusion, our studies show that EBV transformation in conjunction with limiting dilution technology and somatic cell hybridization techniques are useful methods for quantitating, at the B cell clonal level, the human antibody response to foreign Ags and for generating human mAbs of predetermined specificity and high affinity
Automatic method of analysis of OCT images in assessing the severity degree of glaucoma and the visual field loss
Introduction: In many practical aspects of ophthalmology, it is necessary to assess
the severity degree of glaucoma in cases where, for various reasons, it is impossible
to perform a visual field test - static perimetry. These are cases in which the visual
field test result is not reliable, e.g. advanced AMD (Age-related Macular Degeneration).
In these cases, there is a need to determine the severity of glaucoma, mainly on the
basis of optic nerve head (ONH) and retinal nerve fibre layer (RNFL) structure. OCT is
one of the diagnostic methods capable of analysing changes in both, ONH and RNFL
in glaucoma.
Material and method: OCT images of the eye fundus of 55 patients (110 eyes) were
obtained from the SOCT Copernicus (Optopol Tech. SA, Zawiercie, Poland). The authors
proposed a new method for automatic determination of the RNFL (retinal nerve fibre
layer) and other parameters using: mathematical morphology and profiled segmentation
based on morphometric information of the eye fundus. A quantitative ratio of the
quality of the optic disk and RNFL – BGA (biomorphological glaucoma advancement)
was also proposed. The obtained results were compared with the results obtained from
a static perimeter.
Results: Correlations between the known parameters of the optic disk as well as those
suggested by the authors and the results obtained from static perimetry were calculated.
The result of correlation with the static perimetry was 0.78 for the existing methods of
image analysis and 0.86 for the proposed method. Practical usefulness of the proposed
ratio BGA and the impact of the three most important features on the result were
assessed. The following results of correlation for the three proposed classes were
obtained: cup/disk diameter 0.84, disk diameter 0.97 and the RNFL 1.0. Thus, analysis of
the supposed visual field result in the case of glaucoma is possible based only on OCT
images of the eye fundus.
Conclusions: The calculations and analyses performed with the proposed algorithm and
BGA ratio confirm that it is possible to calculate supposed mean defect (MD) of the
visual field test based on OCT images of the eye fundus
Product structures for Legendrian contact homology
Legendrian contact homology (LCH) is a powerful non-classical invariant of Legendrian
knots. Linearization makes the LCH computationally tractable at the expense of discarding
nonlinear (and non-commutative) information. To recover some of the nonlinear information
while preserving computability, we introduce invariant cup and Massey products – and,
more generally, an A∞ structure – on the linearized LCH. We apply the products and A∞ structure in three ways: to find infinite families of Legendrian knots that are not isotopic to
their Legendrian mirrors, to reinterpret the duality theorem of the fourth author in terms of
the cup product, and to recover higher-order linearizations of the LCH
First uses of HAART 300 rings for aortic valve repair in Poland – 4 case studies
Introduction: Aortic valve reconstructions using geometric an- nuloplasty rings HAART 300/200 open new era in aortic valve surgery. The HAART technology resizes, reshapes, stabilizes and simplifies aortic valve repair. The HAART aortic repair rings are designed to be implanted directly into aortic annulus (un- der aortic valve leaflets).
Aim: We present first in Poland 4 cases of aortic valve recon- structions using geometric annuloplasty rings HAART 300. Material and methods: Two patients had type IA aortic insuf- ficiency (due to El-Khoury classification) – they were treated by HAART 300 ring insertion and ascending aorta prosthesis implantation. Third patient, Marfan with type IB aortic insuf- ficiency was repaired by HAART 300 ring implantation followed by remodeling (Yacoub) procedure. Fourth patient with type II aortic insufficiency (due to RCC prolapse) was repaired by HAART 300 implantation and cusp plication.
Results: All patients shows good results on 6 months postop- erative 3D TTE examinations. Conclusions: Presented technique is reproducible and simplify aortic valve reconstructions
Trichloroethylene Exposure during Cardiac Valvuloseptal Morphogenesis Alters Cushion Formation and Cardiac Hemodynamics in the Avian Embryo
It is controversial whether trichloroethylene (TCE) is a cardiac teratogen. We exposed chick embryos to 0, 0.4, 8, or 400 ppb TCE/egg during the period of cardiac valvuloseptal morphogenesis (2–3.3 days’ incubation). Embryo survival, valvuloseptal cellularity, and cardiac hemodynamics were evaluated at times thereafter. TCE at 8 and 400 ppb/egg reduced embryo survival to day 6.25 incubation by 40–50%. At day 4.25, increased proliferation and hypercellularity were observed within the atrioventricular and outflow tract primordia after 8 and 400 ppb TCE. Doppler ultrasound revealed that the dorsal aortic and atrioventricular blood flows were reduced by 23% and 30%, respectively, after exposure to 8 ppb TCE. Equimolar trichloroacetic acid (TCA) was more potent than TCE with respect to increasing mortality and causing valvuloseptal hypercellularity. These results independently confirm that TCE disrupts cardiac development of the chick embryo and identifies valvuloseptal development as a period of sensitivity. The hypercellular valvuloseptal profile is consistent with valvuloseptal heart defects associated with TCE exposure. This is the first report that TCA is a cardioteratogen for the chick and the first report that TCE exposure depresses cardiac function. Valvuloseptal hypercellularity may narrow the cardiac orifices, which reduces blood flow through the heart, thereby compromising cardiac output and contributing to increased mortality. The altered valvuloseptal formation and reduced hemodynamics seen here are consistent with such an outcome. Notably, these effects were observed at a TCE exposure (8 ppb) that is only slightly higher than the U.S. Environmental Protection Agency maximum containment level for drinking water (5 ppb)
Immunological assessment of plant-derived avian flu H5/HA1 variants.
Polypeptide variants of the HA1 antigenic domain of the H5N1 avian influenza virus hemagglutinin (HA) molecule were produced in plants using transient and stable expression systems and fused with His/c-myc tags or with mouse or human Fc antibody fragments. The resulting peptides were purified and used for intramuscular immunization of mice. While the recombinant HA1 variants induced a significant serum humoral immune response in the mice, none of the HA1 preparations induced virus-neutralizing antibodies. Fusion with the Fc fragment improved overall yield of the constructs and allowed purification requiring only a single step, but led to no detectable fusion-related enhancement of immunogenicity or quality of immune response
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