Hepatitis B virus proteins expressed by recombinant vaccinia viruses: influence of preS2 sequence on expression surface and nucleocapsid proteins in human diploid cells

Summary Translation of poliovirus RNA is initiated by entry of ribosomes into the nucleotide sequence (internal ribosomal entry site; IRES) within the 5-untranslated region (5-UTR). Efficiency of this translation initiation in rabbit reticulocyte lysates (RRL) was very low and was greatly enhanced by addition of the ribosomal salt-wash fraction (RSW) prepared from HeLa cells. This stimulating activity in the RSW was partially purified by gel-filtration column chromatography and its molecular weight was estimated to be higher than 240 000. Several proteins that bind specifically to the poliovirus IRES were detected in the active fraction. Among those, a 57 kDa protein, recognized by antibodies against polypyrimidide tract-binding protein (PTB), was found. In addition, La protein (52 kDa) which is a human antigen recognized by antibodies from patients with autoimmune disorders was also detected. Further purification on a hydroxylapatite column resulted in considerable loss of the stimulatory activity, accompanied by a reduction of the apparent molecular weight of active component(s). These results suggest that fully active HeLa cell stimulatory factors for the translation initiation on poliovirus RNA function in RRL as a large complex consisted of several components including PTB and La protein.     

Syntheses and ESR spectra of radicals produced in the thermal decomposition of tetraarylsuccinonitriles

Tetraarylsuccinonitriles 2a – e were synthesized via oxidative dimerization of diarylacetonitriles 1a – e in basic media. The thermal decomposition of 2 results in two identical cyanodiarylmethyl radicals 3 . Both ¹H and ¹³C NMR analyses of 1a – e and 2a – e and ESR spectra of 3a – e are presented and discussed. The results of ESR measurements provide a plausible explanation for the different reactivity of cyanodiarylmethyl radicals 3a – e in free radical polymerization.     

Wiedemann‐Rautenstrauch (neonatal progeroid) syndrome: New case with normal telomere length in skin fibroblasts

Wiedemann‐Rautenstrauch (neonatal progeroid) syndrome is an autosomal recessive condition with characteristic appearance of premature aging present at birth (aged face, natal teeth, and wrinkled skin). Other features of the syndrome are generalized lipoatrophy with specific fat accumulation in the lateral suprabuttock region, hypotrichosis, macrocephaly (pseudohydrocephalus), and mental retardation. We report on a new case that demonstrates all typical features of the syndrome. The girl is now 16 years and 10 months old and has had follow‐up from birth. We measured terminal restriction fragment (TRF) length to evaluate whether the patient's premature aging process is accompanied by shortening of telomere length in her cultured fibroblasts. Mean TRF of 13.5 kb found in our patient's fibroblasts is not shortened as compared to that of normal fibroblasts. Our results differ from those observed in Hutchinson‐Gilford progeria. © 2001 Wiley‐Liss, Inc.     

Micropapillary carcinoma of the parotid gland arising in mucinous cystadenoma

We describe a 45-year-old man who had a 2-year history of a slowly enlarging tumor in the left parotid gland. Histologically, the tumor was a mucinous cystadenoma with focal apocrine differentiation, which revealed a widespread invasive micropapillary adenocarcinoma component. A rim of lymphoid tissue surrounded the margins of the micropapillary carcinoma. The invasive micropapillary adenocarcinoma component was morphologically identical with the invasive micropapillary carcinoma of the mammary gland. The tumor is different from so-far recognized salivary gland tumor entities. Received: 25 October 1999 / Accepted: 13 June 2000     

Defects of natural killer cell activity in children with untreated acute lymphocytic leukemia

Summary Natural killer (NK) activity against cells of the K-562 line was significantly depressed in 12 of 18 children (66%) with untreated acute lymphocytic leukemia (ALL). No suppression of allogeneic NK activity was observed with sera of the patients, regardless of the level of NK depression. The ability of peripheral blood lymphocytes (PBLs) to suppress allogeneic NK activity was tested in two ALL patients — one with no detectable NK activity, and one with high NK activity. No NK-suppressive activity was found with PBLs of the areactive patient; PBLs of the reactive patients exhibited some suppressive activity, but only at a particular suppressor-to-effector cell ratio. Leukemic blasts were resistant to killing by autologous NK cells stimulated by IFN, as well as to killing by allogeneic, IFN-stimulated PBLs. Leukemic blasts of an ALL patient inhibited lysis of K-562 cells in an 18-h, but not in a 4-h NK assay. The inhibition could partly be reversed by pretreatment of ALL cells with alpha interferon, suggesting that the blasts might inhibit the lysis of K-562 targets in a competitive manner. Disturbed function and/or regulation of NK cells may influence attempts at NK cell activation by lymphokines.Abbreviations ALL acute lymphocytic leukemia - AML acute myeloid leukemia - CLL chronic lymphocytic leukemia - CML chronic myeloid leukemia - IFN interferon - IL-2 interleukin-2 - LGL large granular lymphocyte - NK cell natural killer cell - PBL peripheral blood lymphocyte - Poly I:C polyinosinic-polycytidylic acid     

Monoclonal antibodies against transferrin. Precipitating mixtures and lack of inter-species cross-reactivity

Five stable hybridoma lines were prepared using the myeloma cell line P3-X63-Ag.653 and spleen cells of mice hyperimmunized by pig transferrin. All hybridomas grew well in mouse peritoneal cavity and produced antibodies of the IgG₁ subclass. Antibody preparations obtained from ascitic fluids tested for their capacity of antigen precipitation. No precipitation was obtained with single antibodies and with pairs of antibodies. Three out of 10 possible triads gave clear and sharp precipitation zones and rings in immunodiffusion tests performed in agar gel. All 5 antibodies were shown by quantitative enzyme-immunoassay to be specific for pig transferrin: no cross-reaction was obtained with mouse, human, horse and sheep transferrins.     

Hydrogels in endovascular embolization. II. Clinical use of spherical particles

In this study we report the results of clinical experiments, obtained with spherical particles made from poly(2-hydroxyethyl methacrylate) used in the embolization of arteriovenous anastomoses, in the suppression of pulmonary haemorrhage and haemoptysis and in the occlusion of some other arteries. So far we have used these particles in the treatment of 187 patients. It must be stressed that the advantage of spherical particles consists in the simplicity of their introduction into the blood vessel through a catheter, while in the blood vessel itself the particle swells in blood still more, when compared with the particle size in saline. This results in an immediate and permanent haemostatic effect. No revascularization occurs.     

Polymerization of lactams, 55. Cyclic dimer of 6-caprolactam and its polymerization

Polymerization of the cyclic dimer of 6-caprolactam was investigated in N-methyl-2-pyrroli-done solution at 260°C under initiation with 6-aminocaproic acid or anhydrous phosphoric acid on the one hand, and in the solid phase at 230, 260, and 280°C in the absence of any other component or under initiation with anhydrous phosphoric acid, on the other. Monomeric 6-caprolactam was formed in all cases already at the beginning of reaction. It has been suggested that, in addition to the direct incorporation of the cyclic dimer into a polymer chain, the dimer is alos incorporated via the monomer, which is formed from the dimer by an intermolecular transamidation reaction.     

Polymers containing enzymatically degradable bonds. VI.Hydrophilic gels cleavable by chymotrypsin

New types of hydrophilic gels based on N-(2-hydroxypropyl)methacrylamide which contain oligopeptide sequences in the crosslinks were prepared. These gels are enzymatically degradable by chymotrypsin. The rate of their degradation may be varied within a broad range by changes in the length and detailestructure of the oligopeptide sequence in the crosslinks and by changing their network density.     

Infrared spectra and sequence length distribution in free radical styrene/methacrolein copolymers

The method of azoisobutyronitrile (AIBN)-initiated bulk copolymerization of styrene (S) and methacrolein (M) was employed to determine the monomer reactivity ratios r_S = 0.15 and r_M = 0.55 (Q_M = 1.50, e_M = 0.78). Quantitative IR spectroscopy in the region of 4000–450 cm^?1 was used to elucidate the structure of copolymers. In addition to methacrolein units containing aldehyde groups, the copolymers may also contain cyclic hemiacetal structures formed by the reaction of the carbonyls of the neighboring methacrolein units. The carbonyl absorption at 1722 cm^?1 showed that, up to 30 mole-% methacrolein in the copolymer, almost all methacrolein units have free aldehyde groups. The number of cyclic structures increases with the concentration of methacrolein in the copolymer. The experimental data are in agreement with the statistical theory on the sequence length distribution. The shift of the styrene band at 540 cm^?1 to higher wavenumber was investigated and related to the shortening of sequence length of the styrene units. The intensity of the styrene band at 760 cm^?1 was related with the distribution of the MSM triads and the copolymer structure.