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Biomedical subjects

A Płucienniczak

Publications and source records attributed to A Płucienniczak.

At least 19 recordsLinked to original sources
PubMed2004

Trichinella spiralis thymidylate synthase: cDNA cloning and sequencing, and developmental pattern of mRNA expression.

The persistent expression of thymidylate synthase activity has previously been demonstrated not only in adult forms, but also in non-developing muscle larvae of Trichinella spiralis and T. pseudospiralis, pointing to an unusual pattern of cell cycle regulation, and prompting further studies on the developmental pattern of T. spiralis thymidylate synthase gene expression. The enzyme cDNA was cloned and sequenced, allowing the characterization of a single open reading frame of 307 amino acids coding for a putative protein of 35,582 Da molecular weight. The amino acid sequence of the parasite enzyme was analysed, the consensus phylogenetic tree built and its stability assessed. The aa sequence identity with thymidylate synthase was confirmed by the enzymatic activity of the recombinant protein expressed in E. coli. As compared with the enzyme purified from muscle larvae, it showed apparently similar Vmax value, but higher Km(app) values desscribing interactions with dUMP (28.8 microM vs. 3.9 microM) and (6RS,alphaS)-N(5,10)-methylenetetrahydrofolate (383 microM vs. 54.7 microM). With the coding region used as a probe, thymidylate synthase mRNA levels, relative to 18S rRNA, were found to be similar in muscle larvae, adult forms and newborn larvae, in agreement with muscle larvae cells being arrested in the cell cycle.

Amino Acid Sequence↗
PubMed2003

The immune response of rats to vaccination with the cDNA or protein forms of the cysteine proteinase of Fasciola hepatica.

Our previous experiments have shown that intramuscular injection of Sprague-Dawley rats with a pcDNA 3.1 vector carrying cDNA encoding for a cysteine proteinase (CP) of F. hepatica may induce a high level of protection against subsequent infection with F. hepatica metacercariae (mc). The aim of the present study is to compare the immune response of Sprague-Dawley rats vaccinated intranasally with plasmid containing cDNA of CP of the fluke and intramuscularly or intraperitoneally with the recombinated enzyme protein to challenge with fluke metacercariae. In addition, protection following intranasal DNA vaccination was evaluated. Two experiments were carried out. In the first experiment rats were vaccinated twice with 50microg of cDNA containing plasmid or with 100microg protein of recombinated CP. Three weeks after the second vaccination rats were challenged orally with 25 mc. On days 0, 21, 42 and 63 after the challenge blood samples were collected for the evaluation of white blood cell, eosinophil and specific antibody responses. During the second experiment groups of five male and female rats were vaccinated twice intranasally with CPcDNA then challenged with 30 mc and dissected 5 weeks later. Results obtained in the experiments suggested that intranasal immunisation of rats with CPcDNA seems to favour a Th2 regulated antibody response. Intramuscular or intraperitoneal injections of CP protein stimulate both Th1 and Th2-dependent antibodies. Mean worm burdens found in rats vaccinated intranasally 5 or 10 weeks after the challenge were reduced by 61-75% in comparison with the challenge controls which suggests that intranasal vaccination with CPcDNA may protect hosts against F. hepatica infection.

Animals↗
PubMed2003

Characterization of changes in the short unique segment of pseudorabies virus BUK-TK900 (Suivac A) vaccine strain.

Mutant strains of pseudorabies virus (PRV) of reduced virulence, such as Bartha or BUK-TK900, have been used for vaccination purposes for many years. In contrast to the Bartha strain, BUK-TK900 has not been well characterised at the molecular level. The detailed analysis of this vaccine strain was urged by the fact of the isolation in Poland of field strains which were suspected to originate from BUK-TK900. We characterised changes in the U(S) region of this strain, focusing our attention on gE and gI genes. The only deletion, about 300 bp, found in BamHI 7 fragment (covering most of the U(S) region) was located in the 28 K (US2) gene. BUK-TK 900 produced small plaques on all cell lines tested in our laboratory (SK6, Vero, MDBK, 3T3). The plaque size was restored to about 70% of wild type virus plaque size when growing BUK-TK900 virus on 3T3 complementing cell line expressing PRV gE and up to 100% when cell line producing gE and gI was used. Both gE and gI genes from BUK-TK900 and from some derivative field isolates have been amplified by PCR reaction but no deletions in these genes have been found. Molecular weight of gene products differed from wild type proteins: gE was bigger than wild type gE while gI was smaller. Both proteins were correctly recognised by all tested polyclonal and monoclonal antibodies. Radioimmunoprecipitation study showed that BUK-TK900 gE and gI interact forming a complex. The whole ORF of BUK-TK900 gE was sequenced and only few point mutations were found; only two of them led to changes of amino acids in the polypeptide chain. These were: methionine at position 124 replaced by threonine and glutamine at position 162 replaced by arginine. The introduction of first of these mutations (Met to Thr) to PRV wild type strain NIA-3 resulted in 22% reduction of plaque size. This result confirms the importance of this domain of gE for its function; it was found previously by others that deletion of amino acids 125 and 126 reduced virulence and neurotropism of PRV. More changes were found in BUK-TK900 gI sequence. Over 80% of these changes were located in the terminal 1/3rd of the sequence. Some of these mutations may have significant effect on the secondary structure of gI glycoprotein. The change of the secondary structure may be responsible for the decrease of gI stability and the observed reduction of gI molecular mass.

Animals↗
PubMed2001

The quantitative PCR technique resolves ambiguities concerning a small rearrangement of human chromosome 6q12-13.

Karyotype analysis, performed on the basis of chromosome banding pattern, is a standard method used for identification of chromosomal aberrations, both numerical and structural. The application of classic cytogenetic techniques fails, however, to solve all diagnostic problems in certain types of chromosome aberrations. In this study, quantitative polymerase chain reaction technique (Q-PCR) application was applied to verify a cytogenetic diagnosis, which assumed that a difference observed in the banding pattern of homologous chromosome 6q12-13 region of a foetus had resulted from an inversion and/or duplication of the region in question. The obtained results indicate a possibility to use the Q-PCR method in the diagnostics of unbalanced chromosomal aberrations.

Journal Article↗
PubMed1999

Fragments of LINE-1 retrotransposons flanked by inverted telomeric repeats are present in the bovine genome. Homology with human LINE-1 elements.

In the bovine genome we found two intrachromosomal DNA fragments flanked by inverted telomeric repeats (GenBank Accession Nos. AF136741 and AF136742). The internal parts of the fragments are homologous exclusively to the human sequences and to the consensus sequence of the L1MC4 subfamily of LINE-1 retrotransposons which are widespread among mammalian genomes. We found that distribution of homologous human sequences within our fragments is not random, reflecting a complicated pattern of insertion mechanisms of and maintenance of retrotransposons in mammalian genomes. One of the possible explanations of the origin of LINE-1 truncated elements flanked by inverted telomeric repeats in the bovine genome is that extrachromosomal DNA fragments may be modified by telomerase and subsequently, transferred into chromosomal DNA.

Animals↗
PubMed1997

Isolation and characterization of a ColE1-like plasmid from Enterobacter agglomerans with a novel variant of rom gene.

Complete nucleotide sequence of a plasmid isolated from Enterobacter agglomerans has been determined. The plasmid, called pPIGDM1, consists of 2495 base pairs. The analysis of its nucleotide sequence suggested that pPIGDM1 may be a ColE1-like replicon. We confirmed this hypothesis by constructing a pPIGDM1-derived plasmid harboring the cat gene (pBW4), which could be introduced into Escherichia coli cells, and demonstrating that pBW4 cannot replicate in the absence of the polA function and that its copy number is significantly decreased in the pcnB mutant. Like some other ColE1-type replicons (e.g., pBR322), pPIGDM1-derived plasmids can be amplified both by chloramphenicol method and in isoleucine-starved relA mutants but not in relA+ bacteria. Inactivation of the putative rom gene by insertion of an amplicillin-resistance gene resulted in significant increase in pPIGDM1-derived plasmid copy number in E. coli-despite the fact that amino acid sequence of the putative RNA 1 modulator (Rom) protein is only 55.7% identical to the ColE1 analog. The pPIGDM1-derived rom-like coding sequence is also homologous to the rom-like gene present in the Proteus vulgaris plasmid pPvul. We suggest to group all these gene products into a new family called ROMS (RNA one modulators). Since a pPIGDM1-derived plasmid is compatible with other ColE1-like replicons (pMB1-, p15A, RSF1030-, and CloDF13-derived) in E. coli, one may consider pPIGDM1 as a progenitor of new cloning vehicles compatible with most (if not all) of currently used plasmid vectors. Moreover, this plasmid may serve as a source of the new rom-like gene coding for a protein useful in investigation of RNA-protein interactions. A role for the pPIGDM1 plasmid in the host strain is not known.

Amino Acid Sequence↗
PubMed1996

[Etiology of chronic hepatitis as evaluated by liver biopsy and serum samples submitted to the Department of Immunopathology of the National Institute of Hygiene in 1993-1995].

The purpose of this study was to assess the relative incidence of chronic hepatitis in a population of patients with chronic liver disease and to determine the etiological spectrum of this syndrome with special reference to its defined histopathological forms. Histopathology aided by immunohistochemistry, and serology aided by the PCR method were employed in studies of liver biopsy specimens and serum samples, respectively. Out of 1150 patients with chronic liver disease examined, chronic hepatitis was diagnosed in 685 (60% of all cases examined). In this group, there were 308 males aged 18-74 yrs (mean 32 yrs), 153 females aged 18-71 yrs (mean 43 yrs), and 213 children aged 1-17 yrs (mean 8 yrs). Viral infections documented in these patients included HBV (50.4%), HCV (36.2%), HBV/HCV (7.2%) and HBV/HDV (0.7%); cryptogenic and autoimmune hepatitis (AIH) accounted for 2.9% and 2.6% all cases, respectively. In the group of minimal hepatitis (16.1%), HBV infection was documented in 66.4% of cases, HCV-in 29.1%, HBV/HCV-in 3.6% (one case of AIH was included into this group). In the group of mild hepatitis (44.2%), HBV infection accounted for 47.3% of cases, HCV-for 41.9%, HBV/HCV-for 9.9%, and 0.9% was diagnosed as cryptogenic. In the group of moderate hepatitis (19.6%), HBV infection accounted for 50% of cases, HCV-for 37.3%, and HBV/HCV-for 4.5%; cases of cryptogenic and AIH accounted for 3.7% and 4.5%, respectively. In the group of severe hepatitis (20.1%), HBV etiology was found in 44.9% of cases, HCV-in 28.3%, HBV/HCV-in 6.5% and HBV/HDV-in 3.6%; cryptogenic and AIH accounted for 6.5% and 8.0% of cases, respectively. There was a high incidence of low-titer autoantibodies (SMA, ANA and LKM) ranging from 75% in cryptogenic hepatitis and 51% in each HBV and HBV/HCV hepatitis to 46.3% in HCV hepatitis.

Adolescent↗
PubMed1995

Bovine Alu-like sequences mediate transposition of a new site-specific retroelement.

We describe a new family of 3.1-kb repetitive sequences which is present in the bovine genome. The 5' and 3' ends of the unit are flanked with sequences homologous to the 5' and 3' halves of the bovine Alu-like monomer (BM), respectively. Distribution of the 5' ends of the family members in the genome is not random. They are close to the truncated bovine Alu-like dimer (BD) which, in some cases, is followed by 40-bp repeated sequences containing block A of the RNA polymerase III promoter. The ORFs found within the unit code for peptides homologous to amino-acid sequences characteristic for reverse transcriptases (RT). The family members may be considered as mutant mobile elements whose propagation in the genomes was accomplished by means of a process including site-specific recognition with BD. Because of this, we call this family the bovine dimer-driven family (BDDF).

Amino Acid Sequence↗
PubMed1995

Expression and characterization of the multiplied, recombinant preS1 antigen of hepatitis B virus.

The amino acid sequence encoded by the preS1 region of hepatitis B virus genome is expressed on the surface of virions and subviral particles. The preS1 region is involved in the recognition of specific receptors responsible for the attachment of HBV to the host cell. The cell receptor binding site was assigned to the preS1 (20-47 aa) fragment. In order to obtain a large quantity of preS1 binding domains of HBV the expression vector pWX4 was constructed. It contains four tandemly joined DNA sequences, each coding for preS1 (20-49 aa), fused with the 3' end of a DNA fragment coding for 450 aa of beta-galactosidase. E. coli cells transformed with this vector produce fusion protein beta-gal-preSlx4 in the form of inclusion bodies. Owing to the specific trypsin digestion, the preSlx4 domain was cleaved from the fusion protein. The resulting product, a 16 kDa protein, was isolated and purified by anion exchange chromatography. The presence of four Asp-Pro bonds in this sequence and the primary structure of the first 28 N-terminal amino acids were determined. Following the confirmation of the antigenic properties, the recombinant preS1 protein was used for detection of the anti-preS1 response in sera from HBV infected patients.

Amino Acid Sequence↗
PubMed1994

Modulation of antigen-presenting capacity of human monocytes by HIV-1 GP120 molecule fragments.

The two fragments of HIV-1 gp120 molecule were synthesized to study their interaction with human monocytes. Previous observations indicated that recombinant gp120 fragment (aa residues 410-511) encompassing CD4 binding region (rp120cd) induced tumour necrosis factor alpha (TNF) production in monocytes, while a similar fragment (rp120) not containing the CD4 binding sequence (aa 446-511) was inactive. This paper shows that rp120cd depressed monocyte ability to present antigen (PPD) to autologous T lymphocytes while rp120 was noninhibitory. The rp120cd interacted with monocytes but not T lymphocytes. Anti-TNF receptor type A antibody (utr-1) prevented the depression of antigen presentation caused by rp120cd, which suggested a role for TNF and its receptor. The depression of antigen presentation was seen only when monocytes were treated with rp120cd before, but not after, pulse with antigen. Parallel changes were observed in PPD-induced IL-6 production. Thus, induction of TNF by gp120 may be associated with impairment of antigen-presenting capacity of monocytes seen in AIDS patients.

Antigen Presentation↗
PubMed1994

The epidermal growth factor-like domain from tissue plasminogen activator. Cloning in E. coli, purification and ESR studies of its interaction with human blood platelets.

To examine whether the epidermal growth factor (EGF)-like domain Pro47-Asp87 is involved in the interaction of tissue plasminogen activator (t-PA) with platelets, we have expressed this domain in E. coli. The peptide fragment was produced from a plasmid expression vector as a fusion protein with beta-galactosidase Met1-Val444 at high yield in eight clones of E. coli. The fusion protein was purified and subjected to mild acid hydrolysis with formic acid, then the peptide Pro47-Asp87, identified by immunoblotting using specific antibodies to t-PA, was isolated by HPLC. After incubation with blood platelets spin labelled with 16-doxylstearic acid or 5-doxylstearic acid, the Pro47-Asp87 peptide fragment reduced fluidity of the membrane lipid bilayer to the same extent as did intact t-PA as indicated by ESR measurements. Our data suggest that the EGF-like domain of t-PA can directly interact with blood platelets and thus it seems to contain those sites of the t-PA molecule that bind the platelet membrane components.

Base Sequence↗
PubMed1992

Synthesis of a gene encoding bovine substance P precursors and its expression in Escherichia coli.

Using an efficient Escherichia coli expression system, we have been able to obtain the precursor of substance P, alpha-preprotachykinin (alpha PPT). The alpha PPT protein is produced in E. coli as a fusion to beta-galactosidase, and accumulates in the cytoplasm as insoluble inclusion bodies. We also produced protachykinin (alpha PT), i.e., alpha PPT without a signal peptide. Further purification and characterization of the alpha PPT and alpha PT polypeptides strongly suggest that fully purified products can be obtained using our procedures.

Amino Acid Sequence↗
PubMed1992

Effect of Pre-S1 protein on the long-term cultures of human lymphocytes after hepatitis B immunization.

Long-term cultured T-cells, reactive to Pre-S1 protein, were developed from peripheral blood mononuclear cells (PBMC) of individuals after recovery from hepatitis B infection and of vaccine recipients by in vitro Pre-S1 protein stimulation in the presence of IL-2. The proliferative responses to Pre-S1 protein and functional activities of cultured T-cells were characterized.

Cells, Cultured↗