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Biomedical subjects

M Ostrowski

Publications and source records attributed to M Ostrowski.

At least 19 recordsLinked to original sources
PubMed2006

Circulating adhesion molecules during kidney allograft reperfusion.

Adhesion molecule expression is an important event during early transplant failure. The aim of the present study was to examine the release of adhesion molecules during the first minutes of kidney allograft reperfusion in relation to delayed graft function and acute graft rejection. We enrolled 49 renal transplant recipients, including 13 cases of delayed graft function (DGF) and 11 cases of acute graft rejection (AR). Plasma concentrations of E-selectin, VCAM-1 and ICAM-1 after 3 min of reperfusion were significantly higher than in the iliac vein before reperfusion. There was no statistically significant difference between patients with and without DGF as regards E-selectin, VCAM-1 and ICAM-1 concentrations in the iliac vein before and in the renal vein after 3 min of reperfusion. Concentrations of adhesion molecules in the iliac vein before reperfusion and in the renal vein after 3 min of reperfusion did not differ significantly between patients with and without AR except for ICAM-1 iliac vein concentration which was significantly increased in AR patients. Plasma levels of E-selectin, ICAM-1 and VCAM-1 were increased after kidney allograft reperfusion. Moreover, elevated serum levels of ICAM-1 before transplantation correlated with subsequent acute kidney allograft rejection. The results suggest that elevated ICAM-1 levels may be implicated in acute graft rejection.

Cell Adhesion Molecules↗
PubMed2006

A suppression subtractive hybridization approach reveals niche-specific genes that may be involved in predator avoidance in marine Synechococcus isolates.

Picocyanobacteria of the genus Synechococcus are important contributors to marine primary production and are ubiquitous in the world's oceans. This genus is genetically diverse, and at least 10 discrete lineages or clades have been identified phylogenetically. However, little if anything is known about the genetic attributes which characterize particular lineages or are unique to specific strains. Here, we used a suppression subtractive hybridization (SSH) approach to identify strain- and clade-specific genes in two well-characterized laboratory strains, Synechococcus sp. strain WH8103 (clade III) and Synechococcus sp. strain WH7803 (clade V). Among the genes that were identified as potentially unique to each strain were genes encoding proteins that may be involved in specific predator avoidance, including a glycosyltransferase in strain WH8103 and a permease component of an ABC-type polysaccharide/polyol phosphate export system in WH7803. During this work the genome of one of these strains, WH7803, became available. This allowed assessment of the number of false-positive sequences (i.e., sequences present in the tester genome) present among the SSH-enriched sequences. We found that approximately 9% of the WH8103 sequences were potential false-positive sequences, which demonstrated that caution should be used when this technology is used to assess genomic differences in genetically similar bacterial strains.

Bacterial Proteins↗
PubMed2005

Pretransplant nephrectomy in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most common inherited kidney disease and a frequent cause of end-stage renal failure. Transplantation in patients with ADPKD is associated with specific cyst-related problems, especially urinary tract infections (UTI). Although pretransplant nephrectomy has been applied in this group of patients, evidence of the benefits of this strategy is lacking. Therefore, we compared the outcomes and posttransplant complications among patients with or without pretransplant nephrectomy. PATIENTS AND METHODS: ADPKD patients (73) transplanted from cadaveric donors were reviewed retrospectively with regard to posttransplant complications and outcomes. The groups either underwent pretransplant unilateral nephrectomy (n = 30) or were transplanted with native kidneys intact (n = 43). RESULTS: Two patients underwent simultaneous bilateral nephrectomy due to a large size of the polycystic kidneys interfering with the transplant operation. Overall postransplant complications were more frequent in the group without nephrectomy (34% vs 20%); however, the difference was not statistically significant. Most complications were related to cyst infections with 3 deaths (12%) due to lethal septicemia in the group without nephrectomy. No infection-related deaths were noted in the group with pretransplant nephrectomy. CONCLUSIONS: Graft and patient outcomes as well postransplant complications were similar in both groups, independent of previous nephrectomy. It seems that pretransplant unilateral nephrectomy should not be routine and has no advantage over transplantation with both native kidneys intact, although this conclusion is limited by the small number of patients. An Individualized approach should be applied especially when there has been a history of cyst-related infection.

Cadaver↗
PubMed2005

The evaluation of apoptosis and reactive oxygen species in hematopoietic cells derived from heparinized cadaveric organ donors stored short-term at 4 degrees C.

Heparinized cadaveric organ donors are an important source of human organs and potentially of hematopoietic cells for transplantation purposes. The aim of this study was to evaluate the kinetics of programmed cell death in the hematopoietic cells harvested from these individuals and stored short-term at 4 degrees C. We also attempted to assess hematopoietic cell oxidation by measuring reactive oxygen species (ROS) generated by the mitochondria of stored cells. We found that these bone marrow cells harvested and stored at 4 degrees C for 7 days did not display a significant increase in programmed cell death. However, prolonged storage resulted in lower ROS production, indirectly giving evidence of activation of intracellular signaling proteins.

Adult↗
PubMed2005

Experiences in kidney transplantation with duplicated ureters.

INTRODUCTION: The purpose of this study was to evaluate the complications of duplicated ureters in renal transplant recipients. METHODS: Between 1983 and 2004, 12 patients (median age 34 years) received renal transplants from donors with duplicated ureters. In four patients the ureter to bladder anastomoses were performed separately according to the method described by MacKinnon, including two cases transplanted with ureteral catheters because of narrow widths. In the following cases of eight duplicated ureters an anastomosis was performed between the distal part of each ureter to form a common ureteral ostium, which was connected to the urinary bladder. A ureteral catheter was used to the splint ureterovesical anastomosis. RESULTS: No graft loss to ureteral complications was observed. There was no ureteral necrosis in the postoperative period. No clinical symptoms of ureteral junction obstruction were revealed after removing the ureteral catheter. By ultrasound examination four patients showed a slight temporary pyelocaliectasis was observed and four patients developed temporary urinary fistulas. CONCLUSION: Our ureterocystoneostomy procedures with duplicated ureters were safe and useful in kidney transplantation.

Adult↗
PubMed2003

Life under nutrient limitation in oligotrophic marine environments: an eco/physiological perspective of Sphingopyxis alaskensis (formerly Sphingomonas alaskensis).

The oceans of the world are nutrient-limited environments that support a dynamic diversity of microbial life. Heterotrophic prokaryotes proliferate in oligotrophic regions and affect nutrient transformation and remineralization thereby impacting directly on the all marine biota. An important challenge in studying the microbial ecology of oligotrophic environments has been the isolation of ecologically important species. This goal has been recognized not only for its relevance in defining the dynamics of community composition, but for enabling physiological studies of competitive species and inferring their impact on the microbial food web. This review describes the successful isolation attempts of the ultramicrobacterium, Sphingopyxis alaskensis (formerly described as Sphingomonas alaskensis) using extinction dilution culturing methods. It then provides a comprehensive perspective of the unique physiological and genetic properties that have been identified that distinguish it from typical copiotrophic species. These properties are described through studies of the growth phase and growth rate control of macromolecular synthesis, stress resistance and global gene expression (proteomics). We also discuss the importance of integrating ecological and physiological approaches for studying microorganisms in marine environments.

Alaska↗
PubMed2003

An optimization of isolation of early hematopoietic cells from heparinized cadaveric organ donors.

Heparinized cadaveric organ donors are a potential source of hematopoietic cells for transplantation purposes. The aim of this study was to optimize the harvest of early hematopoietic cells from cadaver donors. Accordingly, we noticed that bone marrow cells harvested from cadaver donors should be resuspended in RPMI or Iscove's medium supplemented with heparin or ACD. Bags with harvested marrow should contain 20% atmosphere air during short-term storage/transportation. Finally, we noticed that BMMNC survive short-term storage better if the collected marrow is not depleted of erythrocytes.

Adult↗
PubMed2003

Factors that impact on immediate graft function in patients after renal transplantation.

Kidney transplantation has become therapy of choice for patients with end-stage renal failure. However, many factors may cause graft rejection or delayed graft function, both of which decrease the prognosis for graft survival. For transplantologists the most important endeavor is to eliminate factors responsible for shortening graft function and to find those predictive of immediate graft function. The aim of the study was to investigate which factors influence early graft function. We retrospectively reviewed 442 renal transplant patients performed between 1990 and 1995 in two Szezecin units. All patients received an identical immunosuppressive drug schedule. Three hundred twelve patients who displayed immediate graft function were included in the study group to analyze donor and recipient age and sex, etiology of ESRD, HLA compatibility AB0 and Rh compatibility cold ischemia time, warm ischemia time, antileukocytes antibodies (PRA), and period of dialysis therapy before transplantation. We observed statistical significance for HLA and AB0 compatibility, younger donor age, and shorter cold ischemia time as the most important factors predictive of early graft function and an improved prognosis for graft survival.

ABO Blood-Group System↗
PubMed2003

Variations in temperature of the donor kidney during cold ischemia time and subsequent assessment of reperfusion using the application of thermovision camera.

Cold ischemia time (CIT) and graft reperfusion events are important nonimmunological factors that influence kidney graft function. The optimal temperature for the organs during CIT ranges from 4 degrees C to 8 degrees C. However, preservation of the designated temperature is usually not controlled during standard storage procedures. Aspects of initial graft reperfusion are usually assessed indirectly. Better evaluation of the effectiveness of the early blood supply may improve the surgical outcome. The aim of the study was to monitor the temperature during CIT in the kidney and surrounding area and subsequently to assess graft reperfusion using thermography. Temperature values of the area surrounding the kidney were registered during 8 organ procurements. We observed that the area surrounding the kidney displayed the optimal temperature range only during the first 5 minutes of CIT; later the temperature oscillated between 1 degrees C and 3.5 degrees C. The study proved that the temperature of the preservation fluid is frequently below prescribed. Analysis of the thermograms of 40 transplanted kidneys with the use of a thermovision camera ThermaCAM SC500 showed usefulness of this method to assess reperfusion and blood distribution in the transplanted kidney.

Cold Temperature↗
PubMed2003

Postoperative adaptation of urinary bladder to variable volume of urine in the initial period following kidney transplantation.

OBJECTIVES: Postoperative adaptation of urinary bladder is a process involving all patients after kidney transplantation that is facilitated by improve surgical techniques and new perioperative protocols. METHODS: The study enrolled 102 kidney transplant recipients whose transplantations were performed between 2000 and 2002. The function of urinary bladder was examined: on the day of operation and 2, 4, 8, 12, 16, and 24 weeks following operation. Patients were assessed with respect to bladder adaptation in relation to the period of dialysis. RESULTS: In patients undergoing dialysis up to 24 months, the maximum speed of flow increased from the 2nd week postoperation and regained normal values after 12 weeks. Volume of micturition, cystometric volume, and compliance regained proper values after 24 weeks of observation. CONCLUSION: The findings confirm that adaptation of the bladder is faster among patients who have had dialysis for longer than 12 months. The most useful, economical, and noninvasive assessment of bladder function was obtained with uroflowmetry in combination with daily bladder diary.

Diuresis↗
PubMed2003

Impact of selected factors on early graft function in patients after renal transplantation.

Transplantation is the best treatment for end-stage renal diseases. For transplantologists, it is most important to know the factors that worsen graft survival prognosis. The aim of the study was to investigate factors predictive of graft loss and shortened graft survival. We retrospectively reviewed 442 renal transplant patients between 1990 and 1995 in two Szczecin units, all of whom received a triple-drug immunosuppressive regimen. One hundred thirty patients showed graft disorders such as delayed graft function or primary nonfunction. The occurrence of these disorders was examined as a function of donor and recipient age and sex, cause of ESRD, HLA compatibility, ABO and Rh compatibility, cold ischemia time, warm ischemia time, antileukocyte antibody level (PRA), and period of dialysis therapy before transplantation. The study showed that a high maximal PRA level, incompatibility for ABO group, and a longer warm ischemia time increase the probability of early graft function disorders.

ABO Blood-Group System↗
PubMed2003

B-cell epitopes in the immunodominant p34 antigen of mycobacterium avium ssp. paratuberculosis recognized by antibodies from infected cattle.

Mycobacterium avium ssp. paratuberculosis (M. paratuberculosis) causes Johne's disease, a chronic and fatal enteritis in ruminants. In the last stage of the disease, antibody titres rise and levels of interferon-gamma decrease, suggesting that the host-immune response is switching from a T helper 1 (Th1) to a Th2 profile. In infected cattle, the membrane protein p34 elicits the predominant humoral response against M. paratuberculosis. To map the B-cell epitopes of this antigen, affinity-purified bovine antibodies against the carboxy-terminal region of p34 were used to screen a 12-mer phage display library. Several phage clones carrying peptides resembling fragments of p34 were affinity selected. Based on the predicted amino acid sequence, peptides were chemically synthesized, which demonstrated reactivity with serum from naturally infected and p34-vaccinated cattle. Immunization of mice with these peptides elicited an anti-p34 antibody response. Two B-cell epitopes were identified and characterized. Based on the reactivity and the type of immune response elicited, epitope A was determined to be conformational, whereas epitope B was demonstrated to be sequential. Both epitopes were shown to be present in p34 proteins from M. avium ssp. avium or M. paratuberculosis but absent from M. intracellulare, the other member of the M. avium complex. Furthermore, both epitopes were mapped to regions of p34 that display high variability when compared to homologous proteins from other mycobacterial species of public and animal health importance. We hypothesize that these variable regions of p34 may play a role in the immunobiology of M. paratuberculosis infections.

Amino Acid Sequence↗
PubMed2002

Identification of neutralizing and nonneutralizing epitopes in the porcine reproductive and respiratory syndrome virus GP5 ectodomain.

After infection of swine with porcine reproductive and respiratory syndrome virus (PRRSV), there is a rapid rise of PRRSV-specific nonneutralizing antibodies (NNA), while neutralizing antibodies (NA) are detectable not sooner than 3 weeks later. To characterize neutralizing epitopes, we selected phages from a 12-mer phage display library using anti-PRRSV neutralizing monoclonal antibody (MAb) ISU25-C1. In addition, phages carrying peptides recognized by swine antibodies with high seroneutralizing titer were isolated after subtracting from the library those clones binding to swine anti-PRRSV serum with no neutralizing activity. Two epitopes located in the ectodomain of PRRSV GP5 were identified. One of these epitopes, which we named epitope B, was recognized both by neutralizing MAb ISU25-C1 and swine neutralizing serum (NS) but not by swine nonneutralizing serum (NNS), indicating that it is a neutralizing epitope. Epitope B is sequential, conserved among isolates, and not immunodominant. Antibodies directed against it are detected in serum late after infection. In contrast, the other epitope, which we named epitope A, is hypervariable and immunodominant. Antibodies against it appear early after infection with PRRSV. This epitope is recognized by swine NNA but is not recognized by either neutralizing MAb ISU25-C1 or swine NA, indicating that it is not involved in PRRSV neutralization. During infection with PRRSV, epitope A may act as a decoy, eliciting most of the antibodies directed to GP5 and delaying the induction of NA against epitope B for at least 3 weeks. These results are relevant to the design of vaccines against PRRSV.

Amino Acid Sequence↗
PubMed2002

Freedom from rejection and stable kidney function are excellent criteria for steroid withdrawal in tacrolimus-treated kidney transplant recipients.

OBJECTIVES: This prospective, randomized, multicentre study investigated the efficacy and safety of two tacrolimus-based regimens and their potential to withdraw steroids. METHODS: In total 489 patients were randomised to receive either tacrolimus and MMF (n = 243) or tacrolimus and azathioprine (n = 246) concomitantly with steroids in both treatment groups. The initial oral dose of tacrolimus was 0.2 mg/kg/day, MMF dose was 1 g/day, azathioprine was administered at 1-2 mg/day. Steroids were tapered from 20 mg/day to 5 mg/day. From month 3 onwards, steroids were withdrawn in patients who were free from steroid-resistant rejection and who had serum creatinine concentrations < 160 mumol/L. Study duration was 6 months. RESULTS: Patient survival at month 6 was 98.3% (Tac/MMF/S) and 98.4% (Tac/Aza/S), graft survival at 6 month was 95.0% (Tac/MMF/S) and 93.5% (Tac/Aza/S). The 6-month incidences of biopsy-proven acute rejection were 18.9% (Tac/MMF/S) compared with 26.8% (Tac/Aza/S), p = 0.038. The 6-month incidences of steroid-resistant acute rejection were 2.1% (Tac/MMF/S) and 4.9% (Tac/Aza/S), p = ns. At the end of month 3, steroid withdrawal was performed in 60.5% (Tac/MMF/S) and 48.8% (Tac/Aza/S) of patients, p < 0.01. During months 4-6, 2.7% of patients in the Tac/MMF group had a biopsy-confirmed acute rejection compared with 0.8% of patients in the Tac/Aza group. In patients who continued to receive steroids, the incidences of biopsy-proven acute rejections during months 4-6 were 3.5% (Tac/MMF/S) and 7.1% (Tac/Aza/S). At study end, the steroid-free patients had an excellent kidney function, the median serum creatinine concentration was 119.5 mumol/L (Tac/MMF) and 115.1 mumol/L (Tac/Aza); the median serum creatinine of the total study group was 130.5 mumol/L (Tac/MMF/S) and 132.8 mumol/L (Tac/Aza/S). CONCLUSION: Both tacrolimus regimens are efficacious and safe. The combination of Tacrolimus and MMF achieved a lower rejection rate and permitted a higher proportion of steroid-free patients. The overall incidence of acute rejection was low and kidney function was good.

Adult↗
PubMed2002

Factors influencing low incidence of living donors for renal transplantation in Poland.

PURPOSE OF THE STUDY: To answer the question: "Why are only 3.8% of kidney transplantations in Poland from living donors?" MATERIAL AND METHODS: The research was conducted using data from anonymous polls addressed to family members of dialyzed patients (potential donors). RESULTS: Almost everybody (98%) had heard about the possibility of treating renal insufficiency by kidney transplantation, but only 77% knew about the possibility of giving their own kidney to a related person. Merely 36% had been informed about this treatment method by a doctor. The most common fears within respondents were those of: health worsening after donating a kidney--45%, and the operation itself (taking an organ)--39%.

Adult↗
PubMed2002

Organ procurements in West Pomerania in years 2000-2001.

Year by year the actual number of transplanted organs has been growing in Poland. In the event of the Województwo Zachodniopomorskie (Western Pomeranian Province) the primary activities were focused on informing medical personnel at hospital departments about approaching donors through trainings for such medical personnel. Such activities resulted in both acceptance and support, especially by medical personnel of medium as well as lower ranks. Since 1983 two transplant units have been functioning in the Province: SPSK-2 and S. P. W. S. Z. in Szczecin, and since 2000 two co-ordination offices, too. Main result of our activities can be seen in the number of organs procured for transplantation. In 2000 we had 27.7 procurements per million (ppm), in 2001 there were 39.9 ppm.

Humans↗
PubMed2001

Heparinized cadaveric organ donors (HCOD)--a potential source of hematopoietic cells for transplantation and gene therapy.

BACKGROUND: Hematopoietic stem cells (HSC) from unrelated HLA-matched heparinized cadaveric organ donors (HCOD) are a new potential source of cells for transplantation and gene therapy. In addition, these cells could also be used as adjuvant therapy to increase microchimerism and graft tolerance after transplantations of various solid organs. Our purpose was to develop an efficient method for harvesting hematopoietic cells from HCODs, METHODS: Bone marrow cells were harvested from pelvic bones and/or vertebral bodies from 50 adult HCODs before or up to 3 hr after disconnecting the donor from the respirator. Subsequently, we evaluated the hematological and gasometric parameters of aspirated marrow samples as well as the proliferative potential, viability, and expression of CD34 and AC133 antigens on these cells. RESULTS: We noticed that up to 2-3 hr after disconnecting the donor from the respirator bone marrow cavities do not clot and remain uninfected and that it is possible to aspirate bone marrow mononuclear cells in quantities sufficient to perform allotransplantation. Nevertheless, due to the developing hypoxia and acidosis of the hematopoietic microenvironment the number and proliferative potential of CD34+ and AC133+ cells gradually decreases. Hence, to obtain viable early hematopoietic cells, bone marrow should be aspirated without delay; optimally before HCOD is disconnected from the respirator or at the very latest 2 hr after organ harvest. CONCLUSIONS: Collectively, our results show that early hemopoietic cells may be efficiently harvested from HCOD in large quantities and used for research and/or transplantation purposes. We postulate to create an international network of banks in which hemopoietic stem cells from HCODs could be preserved for therapeutic purposes.

AC133 Antigen↗