A recombinant vaccinia virus expressing hepatitis B virus middle surface protein Restricted expression of HBV antigens in human diploid cells

Summary Several vaccinia virus recombinants inducing the synthesis of the middle surface (M) protein of hepatitis B virus (HBV) were constructed. One of them, denoted vl37, was examined in some detail. The virus replicated nearly to the same extent in various cell lines, viz. human embryo diploid fibroblast LEP and MRC-5 cells, rabbit embryo fibroblast REF cells, TK^– rat RAT-2 cells, and green monkey CV-1 cells. However, the production of M protein was found considerably lower in the human LEP and MRC-5 than in the other cells examined. In addition, the kinetics of M formation were different in these two cell systems, LEP cells lagging significantly behind CV-1 cells. The low-level production of M protein in LEP cells was not increased by repeated vl37 passages in LEP cells, nor by a passage in a laboratory worker accidentally infected with the vl37 virus, nor by shortening the leader sequence preceding the translation initiation codon. The greater part of the M antigen was found to be cell associated, more so in the cells of human than monkey origin. From the major HBV S antigen (HBsAg) isolated from the plasma of chronically infected subjects, the antigen released by cell destruction differed by binding to polymerized human albumin. This property was utilized in ELISA to detect anti-preS2 antibody. Rabbits inoculated intradermally with the vl37 virus developed antibodies reactive in this assay as well as with a synthetic peptide corresponding in the amino acids 14–34 of the NH₂terminus of the HBsAg preS2 region.     

Co-expression of different types of Fc receptors on murine peritoneal macrophages

Simultaneous expression of particular immunoglobulin Fc receptors (FcR) was studied on the plasma membranes of murine peritoneal macrophages. This was facilitated by the use of sheep red blood cells (SRBC) and/or synthetic microspheres coated with monoclonal antibodies of different isotypes. It was concluded that a majority of macrophages bear more than one type of FcR; macrophages bearing at least three types of FcR were present in the peritoneal cavity; macrophages bearing Fc mu R did not bind IgE, IgA or IgG; all macrophages bearing Fc alpha R also expressed Fc gamma 2bR, Fc gamma 3R and Fc epsilon R; all macrophages bearing Fc epsilon R also expressed Fc gamma 2bR and Fc alpha R. Except for Fc alpha R, essentially equivalent numbers of FcR-bearing macrophages were detected when antibody-coated SRBC or polymeric microspheres were used. Simultaneous applications of these reagents permitted the most detailed and direct investigations yet performed of multiple FcR expression on individual cells.     

Infrared spectra and crystallinity of isotactic poly(methyl methacrylate) and of its deuterated analogues

Infrared spectra of partially crystalline and amorphous samples of isotactic poly(methyl methacrylate) (i-PMMA), poly[methyl (α,α,α-²H₃)methacrylate] (i-PMMA-α-CD₃), poly-[(²H₃)methyl methacrylate] (i-PMMA-OCD₃), and poly[(²H₃)methyl (α,α,α,2,2-²H₅)methacrylate] (i-PMMA-D₈) were measured. Infrared spectra of the pure crystalline forms of these substances were obtained by digital separation. It was found that in acetonitrile, CDCl₃, and toluene solutions, i-PMMA has the same conformational structure as in the amorphous state; conformational structures of crystalline i-PMMA are not present in the solutions in measurable amounts.     

Poly(ethylene glycol)s containing enzymatically degradable bonds

The possibility to use poly(ethylene glycol) (PEG) as a synthetic, water-soluble polymeric carrier of biologically active compounds was investigated. The relationship between structure of oligopeptide (amino acid)-PEG conjugates and their hydrolysis catalyzed by chymotrypsin was studied. Two types of derivatives were synthesized: Derivatives of PEG 2000, containing an oligopeptide sequence terminating in p-nitroaniline (drug model) and higher molecular weight derivatives of PEG 2000 containing in the main chain enzymatically and hydrolytically degradable bonds. The rates of chymotrypsin catalyzed release of p-nitroaniline at pH 8,0 and 25°C were determined over a range of substrate concentrations to derive values for k_cat and K_M. The influence of the length and detailed structure of the oligopeptide sequence on the rate of hydrolysis was demonstrated. Comparison with copolymers of N-(2-hydroxypropyl)methacrylamide and poly(maleic anhydride-co-vinylpyrrolidone) showed that the sterical hindrance of the formation of the enzyme-substrate complex is much less pronounced in the PEG-oligopeptide conjugates. The latter conclusion is also valid in the case of cleavage of PEG derivatives which contain enzymatically degradable bonds in the main chain. The incorporation of a single amino acid residue (phenylalanine) into the main PEG chain is sufficient to make the polymer susceptible to chymotrypsin catalyzed hydrolysis.     

Effect of insulin on sex differences in the intake of glucose solutions in rats

Adult male and female Wistar rats maintained on ad lib diet were given a choice between tap water and a solution of glucose in the concentration of either 5 or 12%. Both sexes exhibited a marked preference for glucose solutions. With the 5% solution the volume intake was similar in both sexes and the total calorie intake was normal. With the 12% solution the volume intake was higher in females than in males, while in both sexes the total calorie intake was increased to a similar (maximum acceptable) level. Treatment with Protamine Zinc Insulin (PZI) in a daily dose of 40 U/kg b.w. markedly increased the intake of the 5% solution in both sexes, but significantly more in females than in males, thus revealing sex differences which were not manifest in untreated rats. PZI treatment had little effect on 12% glucose solution intake, presumably because with this solution the total calorie intake was increased to a maximum already in untreated rats.     

Epidemiology of achondroplasia: A population‐based study in Europe

Achondroplasia is a rare genetic disorder resulting in short‐limb skeletal dysplasia. We present the largest European population‐based epidemiological study to date using data provided by the European Surveillance of Congenital Anomalies (EUROCAT) network. All cases of achondroplasia notified to 28 EUROCAT registries (1991–2015) were included in the study. Prevalence, birth outcomes, prenatal diagnosis, associated anomalies, and the impact of paternal and maternal age on de novo achondroplasia were presented. The study population consisted of 434 achondroplasia cases with a prevalence of 3.72 per 100,000 births (95%CIs: 3.14–4.39). There were 350 live births, 82 terminations of pregnancy after prenatal diagnosis, and two fetal deaths. The prenatal detection rate was significantly higher in recent years (71% in 2011–2015 vs. 36% in 1991–1995). Major associated congenital anomalies were present in 10% of cases. About 20% of cases were familial. After adjusting for maternal age, fathers >34 years had a significantly higher risk of having infants with de novo achondroplasia than younger fathers. Prevalence was stable over time, but regional differences were observed. All pregnancy outcomes were included in the prevalence estimate with 80.6% being live born. The study confirmed the increased risk for older fathers of having infants with de novo achondroplasia.     

RPG1: an essential gene of Saccharomyces cerevisiae encoding a 110-kDa protein required for passage through the G1 phase

In Saccharomyces cerevisiae cells a number of genes are required for progression through, or else to pass beyond, the G₁ phase. We characterized a novel gene, RPG1, which is also involved in this phase. RPG1 is an essential gene encoding a 110-kDa evolutionarily conserved protein. Elutriated or α-factor-synchronized cells of the rpg1-1 temperature-sensitive mutant were arrested in the first cell cycle when shifted to a non-permissive temperature. The cells remained unbudded and neither grew nor duplicated DNA. rpg1-1 cells synchronized in S phase completed mitosis and arrested as unseparated G₁ cells after a shift to a non-permissive temperature. Similarly, the asynchronous rpg1-1 cells accumulated in G₁ at the non-permissive temperature, but mother and daughter cells did not separate. A bulk of Calcofluor-stained material was localized in the region adjacent to the cell septum. Our data show that Rpg1p is required for passage through the G₁ phase and may be involved in growth control. Data published recently indicate that Rpg1p exhibits significant sequence similarity to a subunit of the mammalian translation initiation factor 3. Received: 6 October 1997 / 8 November 1997     

Analysis of the renal tissue of a woman chronically exposed to cadmium

Summary In a 61-year-old woman, who had been exposed for 20 years to cadmium in the production of Ni-Cd batteries, nephrectomy of the contracted kidney was performed. The removed kidney was examined histologically and the cadmium concentration was determined in the cortex (44.97 g g^–1) and in the medulla (7.71 g g^–1). The homogenates of the renal cortex and medulla were subjected to gel filtration on Sephadex G-75. In the cortex, as well as the medulla, cadmium was predominantly found in the low-molecular (metallothionein) fraction, but in the cortex, Cd content in this fraction was six times higher than in the medulla. The determination of SH groups and proteins in high- and low-molecular fractions indicates an induction of the metallothionein formation primarily in the renal cortex.     

Damage and repair of the immature rat cerebellum after cis-dichlorodiammineplatinum II (cis-DDP) treatment. An ultrastructural study

Summary The aim of this electron microscopy study was to further investigate the effects of cis-dichlorodiammineplatinum (cis-DDP) on the cerebellum of the immature rat. Ten-day-old animals were treated with cis-DDP subcutaneously and killed after 1, 7, 15 or 21 days. On postinjection day 1, cis-DDP effects were evident mainly in the external granular layer, with nuclear damage in many dividing cells, while their cytoplasm appeared to be less affected. Some binucleate cells were also present. On the contrary, in postmitotic or more differentiated cells, only cytoplasmic alterations were found. At later stages (postinjection day 7), the frequency of damaged cells in the external granular layer decreased, but there was a cellular deficit in the internal granular layer. Many postmitotic neurons underwent coagulative necrosis. Finally (postinjection days 15 and 21), the cellular deficit was partly compensated for by reactive structures, e.g., glial cell fibers, which underwent hypertrophy after initial edema. Moreover, packing densities of Bergmann astrocytes and oligodendrocytes were higher.This study is a part of the scientific exchange program Proliferation and differentiation of normal and tumor cells between the Italian National Research Council and the Czechoslovak Academy of Sciences     

Effect of dihydroergosine (DHESN) on the serotoninergic system and behaviour: Is DHESN a new antidepressive agent?

Acute (50.0 mg/kg) and repeated (0.1–10.0 mg/kg) administration of dihydroergosine (DHESN) to rats over 5 days lowered the concentration of 5-HIAA in the brain. DHESN given acutely increased the brain 5-HT in p-CPA-treated animals and diminished the probenecid-induced increase in brain 5-HIAA. In pargyline-treated rats DHESN enhanced the 5-HT/5-HIAA ratio. DHESN administered to rats repeatedly over 5 days decreased the level of 5-HT in blood platelets, and in vitro at concentrations of 10^-4 M and 10^-3 M inhibited the uptake of [¹⁴C]-5-HT in platelets. DHESN (10.0–100.0 mg/kg) potentiated the 5-HT syndrome produced in rats by pargyline and 5-HTP. This potentiation was blocked with cyproheptadine but not with haloperidol. DHESN (1.0 and 10.0 mg/kg) lowered the locomotor activity of rats and 10.0 mg/kg DHESN also reduced the duration of immobility in rats forced to swim in a restricted space. The results indicate that DHESN, like antidepressants, decreases the turnover of serotonin in the brain and potentiates the 5-HT-mediated behaviour. This might suggest that the drug should be further investigated for its potential antidepressive properties.