PubMed Health⌕ Search

Biomedical subjects

D Bartosik

Publications and source records attributed to D Bartosik.

At least 19 recordsLinked to original sources
PubMed2001

Characterization and sequence analysis of the replicator region of the novel plasmid pALC1 from Paracoccus alcaliphilus.

The replicator region of a low-copy-number plasmid, pALC1, of Paracoccus alcaliphilus JCM 7364 was cloned in a form of the minireplicon pALC100 (3.6 kb). The host range of the minireplicon embraces several species of genus Paracoccus, as well as Agrobacterium tumefaciens, Rhizobium leguminosarum, and Rhodobacter sphaeroides (all belonging to alpha-Proteobacteria), but not Escherichia coli. The complete nucleotide sequence of the replicator region (2276 bp) revealed the presence of one complete open reading frame coding for the 28.4-kDa protein (RepA) with similarity to replication proteins of plasmid pSW500 of Erwinia stewartii and pVS1 of Pseudomonas fluorescens. The iteron-like region was identified upstream of the repA gene and consisted of two clusters of repeated sequences (17 bp long) separated by a putative DnaA box. Analysis of the predicted amino acid sequence of two adjacent incomplete ORFs suggests the localization of repA between genes involved in conjugation (traG) and partitioning (parA) within the pALC1 genome.

Amino Acid Sequence↗
PubMed2001

Identification of the partitioning site within the repABC-type replicon of the composite Paracoccus versutus plasmid pTAV1.

The replicator region of composite plasmid pTAV1 of Paracoccus versutus (included in mini-replicon pTAV320) belongs to the family of repABC replicons commonly found in plasmids harbored by Agrobacterium and Rhizobium spp. The repABC replicons encode three genes clustered in an operon, which are involved in partitioning (repA and repB) and replication (repC). In order to localize the partitioning site of pTAV320, the two identified incompatibility determinants of this mini-replicon (inc1, located in the intergenic sequence between repB and repC; and inc2, situated downstream of the repC gene) were PCR amplified and used together with purified RepB fusion protein (homologous to the type B partitioning proteins binding to the partitioning sites) in an electrophoretic mobility shift assay. The protein bound only inc2, forming two complexes in a protein concentration-dependent manner. The inc2 region contains two long (14-bp) repeated sequences (R1 and R2). Disruption of these sequences completely eliminates RepB binding ability. R1 and R2 have sequence similarities with analogous repeats of another repABC replicon of plasmid pPAN1 of Paracoccus pantotrophus DSM 82.5 and with centromeric sequences of the Bacillus subtilis chromosome. Excess RepB protein resulted in destabilization of the inc2-containing plasmid in Escherichia coli. On the other hand, the inc2 region could stabilize another unstable replicon in P. versutus when RepA and RepB were delivered in trans, proving that this region has centromere-like activity. Thus, it was demonstrated that repA, repB, and inc2 constitute a functional system for active partitioning of pTAV320.

Bacterial Proteins↗
PubMed2000

Plasmid occurrence and diversity in the genus Paracoccus.

The results of screening for the occurrence of plasmids in several strains representing 11 out of 13 species of the genus Paracoccus are presented. We show that plasmids (ranging in size from 2.7 to above 450 kb) are widely distributed in this genus. Only one tested strain (P. alkenifer) appears to be plasmid-free. The majority of the strains harbour at least two plasmids, one of which usually fits into the class of megaplasmids.

Paracoccus↗
PubMed1997

Complete nucleotide sequence of the replicator region of Paracoccus (Thiobacillus) versutus pTAV1 plasmid and its correlation to several plasmids of Agrobacterium and Rhizobium species.

The complete nucleotide sequence of the replicator region of pTAV1, a cryptic, low copy number plasmid of Paracoccus versutus, was determined. The minimal replicon sequence (3149 bp) included in pTAV203/18 contains two open reading frames with coding capabilities for putative polypeptides of 23.8 (RepX) and 46 kDa (RepC'). The two genes have the same transcriptional polarity and both seem to be essential for replication of pTAV203. The predicted amino acid sequence of RepC' shows significant homology with the major replication-associated proteins of several Agrobacterium and Rhizobium plasmids. A probable origin of replication (oriV) was proposed to be localized at the 3' terminal end of the repC' gene.

Amino Acid Sequence↗
PubMed1997

Construction of mobilizable cloning vectors derived from pBGS18 and their application for analysis of replicator region of a pTAV202 mini-derivative of Paracoccus versutus pTAV1 plasmid.

Two mobilizable cloning vectors, designated pABW1 and pAWB2, were constructed basing on the E. coli vector pBGS18 and oriT originating from RK2. In pABW2 the kanamycin resistance gene was replaced by a novel tetracycline resistance cassette derived from Tn1721. Both vectors, specific for E. coli, allow to perform the cloning steps in E. coli and then to efficiently transfer the constructs by conjugation to the host of choice. A vector which cannot propagate in the given host can be applied for identification of the host specific plasmid replicator regions. With the use of pABW2 we defined the minimal replicator region of pTAV202-a mini-derivative of the large pTAV1 plasmid of P. versutus. We also proved that RepC' encoded on this fragment is the principal initiator replication protein and that oriV is located along its coding sequence.

Cloning, Molecular↗
PubMed1987

Immunoproteins in the endometrium: clinical correlates of the presence of complement fractions C3 and C4.

The presence of complement fractions C3 and C4 in endometrial tissue was studied in a consecutive series of patients undergoing diagnostic laparoscopy, to determine their specific association with endometriosis. The incidence of complement in eutopic endometrium of patients grouped according to four diagnoses was: endometriosis, 66% positive (23 of 35); active pelvic inflammatory disease, 85% positive (11 of 13); combined endometriosis with pelvic inflammatory disease, 25% positive (one of four); laparoscopically normal pelvis, 67% positive (10 of 15). These differences were not statistically significant. Complement was equally likely to be found in proliferative, secretory, menstrual, or inflammatory endometrium. Endometrial complement was found less frequently in patients with severe endometriosis as compared with those with the mild form. Among patients with endometriosis and infertility, complement was much more likely to be found in patients with primary infertility than in those with secondary infertility (p less than 0.007). In short-term follow-up of these patients, the absence of complement in the eutopic endometrium appeared to be a good predictor of subsequent pregnancies.

Complement C3↗
PubMed1986

Endometrial tissue in peritoneal fluid.

Peritoneal fluid (PF) was studied for the presence of endometrial tissue in a consecutive series of 67 women (with documented tubal patency) undergoing diagnostic laparoscopy, tubal lavage, and hysteroscopy. PF was completely aspirated from the cul-de-sac both before and after uterine irrigation. The PF was then analyzed for the presence of endometrial tissue. In native PF no significant difference in the incidence of endometrial tissue between patients with (19%) and without (11%) endometriosis (P = 0.6) was observed. Refluxed PF, obtained after uterine irrigation, showed a significantly higher incidence of endometrial tissue in women with endometriosis (76%) as compared to controls (42%) (P = 0.03). We propose two models to explain the development of endometriosis. These are not mutually exclusive, may be independent of each other, and may represent two distinct pathophysiologic disease processes.

Adolescent↗
PubMed1975

Rhythms of progesterone and corticosterone in the pms-treated rat: relationship to ovulation.

Precocious ovulation was induced in 26-day-old rats by means of 25 IU pregnant mare's serum gonadotrophin (PMS). Rats were given injections at either 09.00 or 16.00 in order to determine whether the course of pubertal changes in corticosterone (B), progesterone (P) or time of ovulation would be dependent upon the time of injection. Blood samples were collected by decapitation at 4-h intervals on the day of expected ovulation (day 28). In saline-treated controls at 28 days of age there was a demonstrable daily variation in both serum B and P with maximum values at 16.00 and minimum values at 08.00. In rats given PMS at 09.00, there was a peak of P and B at 16.00 on day 28 but the values were higher than in controls. Ovulation took place at 24.00 on day 28-29. In rats given PMS at 16.00 the pattern of P and B was different, with continual high values from 16.00 to 04.00 at 28 days of age; ovulation took place later in this group (between 02.00-08.00 on day 28). It can be concluded that there is a daily rhythm of P a few days before puberty and that the induction of precocious ovulation with PMS is associated with a different pattern of B and P and a different time of ovulation depending upon when PMS is administered.

Adrenal Glands↗
PubMed1975

Precocious puberty: the effect of adrenalectomy on PMS-induced ovulation and progesterone secretion.

Female Sprague-Dawley derived rats were received at 21 days of age and either sham-operated or adrenalectomized on that day. Half of the animals received either 25 IU pregnant mare's serum gonadotrophin (PMS) or 0.9 saline at 9 AM on the next day; the other half were injected at 26 days of age. On the day of expected ovulation (days 24-25 and days 28-29) the rats were killed at 4-hr intervals and the incidence of ovulation determined. Serum progesterone and corticosterone were measured with the intent of comparing the pattern of these steroids with the timing and incidence of ovulation. Twenty-two-day-old rats given PMS ovulated later (at 0400 on day 25) than did the 26-day-old rats (at 2400 on day 28). Adrenalectomized ADRX rats ovulated later than intact controls at both ages (ovulation complete at 1600 on days 25 and 29, respectively). There was a reduced ovarian weight response to PMS in ADRX rats but uterine weights were not consistently different from intact PMS-treated rats. Associated with the different timing of ovulation and organ weight response in the ADRX rats there was a lower serum progesterone response on days 24-25. In intact PMS-treated rats, the rhythm of the serum corticosterone was different in the two age groups. It is concluded that adrenalectomy alters the normal response to PMS resulting in a delay in the time of ovulation. It is possible that the adrenal normally participates in the induction of ovulation after PMS, possibly by acting as an internal priming agent to facilitate gonadotrophin release in the young rat.

Adrenal Glands↗
PubMed1975

Endometrial dating correlated with progesterone levels.

The aim of this work was to document the validity and usefulness of progesterone determination instead of endometrial biopsies as evidence for ovulation within a menstrual cycle. The presence of progesterone in amounts greater than 2 ng/ml of plasma was always associated with a secretory endometrium, ie, the endometrium was matured beyond cycle day 14 as diagnosed by classical histologic dating. The remarkable simplicity of quantitating luteal phase progesterone levels by this radioimmunoassay warrants their extended use for evaluating the physiology and the pathology of the corpus luteum.

Biopsy↗