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Biomedical subjects

M Romanowski

Publications and source records attributed to M Romanowski.

At least 19 recordsLinked to original sources

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↗

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↗

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↗

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↗

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↗

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↗

[Laryngeal mask of gastroesophageal reflux disease].

Gastroesophageal reflux disease has become a serious problem not only for general practitioners but for other specialists as well. It is caused by the fact that its clinical picture and symptomatology are very rich. Beside characteristic symptoms such as: heartburn, eructation, gastric contents reflux, epigastric burning or dysphagia, there may appear extroesophageal symptoms (frequently as single or leading ones). It is generally though that the above symptoms result from the direct effect of gastric contents on throat and larynx and/or through vagus nerve. Direct effect of hydrochloric acid and other gastric juice components on larynx may be the cause of subglottic laryngostenosis, neoplastic transformation and development of squamous cell carcinoma. This, it may be concluded that gastroesophageal reflux disease should be in the sphere of interest of laryngologists as well as gastroenterologists. Cooperation of these specialists is particularly useful as it quickens the choice of proper diagnostic procedure and an introduction of an appropriate therapeutic treatment.

Gastroenterology↗

Interaction of a highly potent dimeric enkephalin analog, biphalin, with model membranes.

Biphalin, (Tyr-D-Ala-Gly-Phe-NH)2, is a highly potent dimeric analog of enkephalin. Its analgesic efficacy is due in part to its ability to permeate the blood-brain barrier. To aid in understanding the mechanism of the transmembrane movement we determined and analyzed the permeability and partition coefficients of biphalin and a series of analogues where F, Cl, I, NO2, or NH2 were placed in the para position of the aromatic rings of Phe4,4'. Liposomes composed of neutral phospholipids and cholesterol were used as the model membrane. The overall good correlation between permeability and water-membrane partition coefficients suggests that the movement of biphalins across the model membrane is controlled by diffusion and depends on the water-membrane partition coefficient. To explain the observed correlation between permeability and the electron withdrawing/donating character of the substituents in the phenylalanine ring, we examined various folding patterns of Leu-enkephalin, an endogenous pentapeptide that exhibits affinities toward the same classes of opioid receptors (delta and mu). The observed permeabilities and partition coefficients of biphalin and analogues, as well as the tyrosine side chain accessibility, are consistent with the presence of the type of folding where the tyrosine and phenylalanine side chains are in a close contact. We propose that the aromatic ring interaction can promote the peptide permeability by stabilizing a more compact structure of biphalin that would minimize the number of hydrogen bonds with water and therefore enhances partitioning into the model membrane.

1,2-Dipalmitoylphosphatidylcholine↗

Lipid membrane permeability of modified c[D-Pen2, D-Pen5]enkephalin peptides.

Permeability coefficients of a series of analogues of a potent opioid peptide, c[D-Pen2, D-Pen5]enkephalin, were measured in a model membrane system. The analogues included hydrophobic amino acid substitutions on position 3. Liposomes of a mixed composition consisting of zwitterionic lipids and cholesterol served as the model membranes. The obtained permeability coefficients range between 0.38 x 10(-12) and 2.9 x 10(-12) cm/s. These data were correlated with the hydrophobicity scale of Nozaki and Tanford (J. Biol. Chem. 246, 1971, 2211-2217) (correlation coefficient = 0.9933) and with determinations of lipid order perturbation by differential scanning calorimetry (correlation coefficient = -0.9779). The reasonably good correlation obtained within the family of analogues substituted on position 3 (Gly, Ala, Leu, Phe) indicates that changes in permeabilities are primarily related to increases in the partition coefficient of the peptide. However, Phe residue added on the N-terminal end of the peptide (position 0) does not appear to follow the observed trend, showing stronger lipid perturbation and lower permeability compared to the Phe3 analog. This observation demonstrates that each class of peptide modifications requires a new basis of permeability analysis and predictions.

Calorimetry, Differential Scanning↗

Structural domains of phytochrome deduced from homologies in amino acid sequences.

A method of semiempirical identification of structural domains is proposed. The procedure is based on the comparison of amino acid sequences in groups of homologous proteins. This approach was tested using 32 known protein sequences from different cytochrome b5, cytochrome c, lysozyme, hemoglobin, and myoglobin proteins. The method presented was able to identify all structural domains of these reference proteins. A consensus secondary structure provided information on structural content of these domains predicting correctly 21 of 23 (91%) of alpha-helices. We applied this method to six homologous phytochrome sequences from Avena, Arabadopsis, Cucurbita, Maize, Oryza, and Pisum. Some of the identified domains can be assigned to the known tertiary structure categories. For example, an alpha/beta domain is localized in the region known to stabilize the phytochrome chromophore in the red light absorbing form (Pr). One alpha-helical and one alpha/beta domains are localized in regions important for the chromophore stabilization in the far-red absorbing form (Pfr). From an analysis of noncovalent interaction patterns in another domain it is proposed that a phytochrome dimer contact involves two segments localized between residues 730 and 821 (using numbering of aligned sequences). Also, a possible antiparallel beta-sheet structure of this region has been suggested. According to this model, the long axis of the interacting structures is perpendicular to a twofold symmetry axis of the phytochrome dimer.

Amino Acid Sequence↗

Use of a filter disc micro-sampling atomic absorption method for blood lead level screening.

The filter-paper disc method using capillary blood was compared with the Delves techniques using venous blood. For routine screening, the filter-paper disc method was found to yield rapid and reasonable results and, in addition, to be relatively inexpensive. The method was used to screen the blood lead level of over 1000 children in pediatric hospitals of four major cities in Canada. Results of the survey are discussed with regard to sampling technique, analytical technique, and the statistical analysis.

Blood Chemical Analysis↗

Laparoscopic removal of renal cysts in patients with ADPKD as an alternative method of treatment and patient preparation for kidney transplantation: preliminary results.

BACKGROUND: The most frequent genetic disease of the kidneys occurring in 1 of 1000 inhabitants is autosomal-dominant polycystic kidney disease (ADPKD). Growing renal cysts compress the kidney resulting in damage to parenchyma and functional disorders. Around 10% of these patients are dialyzed due to terminal renal insufficiency. With the advent of laparoscopic techniques, the idea of laparoscopic excision of cysts seemed a tempting alternative to nephrectomy. We assessed the preliminary results of laparoscopic treatment of polycystic kidneys compared with open nephrectomy for patients with ADPKD. MATERIALS AND METHODS: Thirty ADPKD patients were treated between 2000 and 2004. Eleven procedures in five men and six women of mean age 51 years included laparoscopic cyst excisions. In the remaining 19 patients (six men and 13 women) of mean age 54 years, nephrectomy was done. Indications for surgery included pain due to compression by large cysts and cyst contamination. Patients after nephrectomy were prepared for renal transplantation when necessary. RESULTS: Laparoscopic polycyst removal produced better effects than nephrectomy. Mean operative time was significantly shorter (86 minutes for cyst removal vs 108 minutes for nephrectomy; P < .05). Postoperative pain measured with the VAS scale was reduced in patients after laparoscopy. Hospital stay was shorter (5 vs 9 days), as well as time to recovery. Other benefits of laparoscopic cyst removal included maintained urination in the patient and no need for erythropoietin substitution, as well as reduced risk of cyst contamination. When eligible for renal transplantation, patients after laparoscopic polycyst removal have smaller kidneys that do not interfere with the graft and the risk of infection during immunosuppression seems lower. CONCLUSION: Although larger series of patients are required in patients with ADPKD, laparoscopic polycyst removal seemed superior to early nephrectomy.

Female↗

Hypoxanthine as a graft ischemia marker stimulates catalase activity in the renal vein during reperfusion in humans.

BACKGROUND: The impairment of organ function derived from ischemia-reperfusion injury is still an important problem in solid organ transplantation. Cell alterations induced by ischemia prime the tissue for subsequent damage occurring during the reperfusion phase. Purine nucleotides and oxypurines are products of adenine nucleotide degradation. Reperfusion and reoxygenation are characterized by great production of reactive oxygen species and free radicals. On the contrary, superoxide dismutase, catalase, glutathione, and glutathione peroxidase are involved in protecting against free radicals. The aim of the study was to examine the correlation between concentrations of ischemia markers (hypoxanthine or inosine) and the activity of erythrocyte superoxide dismutase, catalase, or glutathione peroxidase. PATIENTS AND METHODS: The study included 40 renal transplant recipients. Before anastomosis of the kidney vessels with the recipient's iliac vessels, a "0" blood sample was taken from the iliac vein. Then, after anastomosis, the renal vein of the graft was cannulated and blood samples I, II, and III were obtained. The reperfusion of the transplanted kidney was measured with a thermovision camera ThermaCAM SC500. RESULTS: The plasma concentrations of hypoxanthine and inosine increased in statistically significant fashion immediately after total tissue reperfusion (P < .0001). Catalase activity at 4 minutes after total tissue reperfusion correlated positively with hypoxanthine concentrations immediately after total tissue reperfusion (Rs = +0.49), 2 minutes after total tissue reperfusion (Rs = +0.47), and 4 minutes after total tissue reperfusion (Rs = +0.46). There were no statistically significant correlations between hypoxanthine or inosine concentrations or superoxide dismutase or glutathione peroxidase activities. CONCLUSIONS: The results of the present study suggest that catalase activity may correlate with the concentration of hypoxanthine in the graft renal vein and other mediators of oxidative stress.

Adult↗

Impact of presence of HBs antigen and anti-hepatitis C virus and anti-cytomegalovirus antibodies on transplanted kidney survival.

INTRODUCTION: Infections are one of the most common complications after organ transplantation. Viral infections such as hepatitis type B (HBV) and C (HCV) or cytomegalovirus (CMV) infections are among the most serious ones. A high frequency of HBV and HCV infections has been recognized in kidney recipients. Viral infections play a special role in graft recipients because of clinical symptoms influencing graft function and recipient survival. Immunosuppressive treatment to decrease immunological reactions after organ transplantation may increase the risk of viral infections. The aim of this study was to evaluate the impact of the presence of HBs antigen and HCV and CMV antibodies on patient and graft survivals. MATERIAL AND METHODS: Two hundred one enrolled kidney transplantation patients (96 women and 105 men) were treated with the same immunosuppressive regimen. Age, sex, and viral state (HBs antigen, anti-HCV and anti-CMV antibodies) were evaluated in every patient. Statistical analysis was performed with the Gompertz model, Kaplan-Meier curves and Cox proportional hazard tests. RESULTS: The presence of HBs antigen was detected in 161 patients (20.4%), HCV antibodies in 61 recipients (30.3%); and CMV antibodies in 12 patients (5.9%). Eighty-seven recipients (43.4%) were seronegative. Average recipient age was 38.5 years. CONCLUSION: Time of graft function was independent of the presence of HBs antigen or HCV or CMV antibodies.

Adult↗

Early acid-base balance disorders during kidney transplantation.

INTRODUCTION: Reperfusion is a crucial moment in kidney transplantation. Resumption of blood flow is associated with many metabolic changes, which result from the kidney's initial condition and preservation. These biochemical alterations including the acid-base balance are the part of ischemia-reperfusion injury. The study's purpose was to examine acid-base balance during the first 30 minutes after reperfusion of the transplanted kidney. MATERIALS AND METHODS: The 30 recipients (13 men, 17 women) averaged ages of 46 +/- 14 years. Measurements performed nine times (at 0, 1, 3, 5, 10, 15, 20, 25, and 30 minutes after unclamping renal vessels) included: gas analysis, expiratory Pco(2), tidal volume, and respiratory rate. The evaluation of the temporary acid-base balance was performed on the basis of common parameters: pH, Pco(2), [HCO(3)(-)], and base excess (BE). The patients were under general anesthesia with stable external conditions of O(2) saturation, heart rate, blood pressure, and temperature. Blood samples were analyzed using Corning 278 and 248 blood gas analyzer; vital parameters were recorded using Ohmeda 5250 RGM and Dräger Sulla 909V/Julian apparatus. RESULTS: The analysis showed increasing metabolic acidosis with coexisting increase in blood Pco(2), changes that were most intense in the first minute of reperfusion. Decreasing mean pH index did not exceed physiologic limits, but the final mean values of [HCO(3)(-)] and BE were in most of cases below the limit. Increased expiratory air Pco(2) was most intense in the first 3 minutes reaching a maximum at about 15 minutes. CONCLUSIONS: The beginning of reperfusion was the cause of increasing metabolic acidosis, which was partially compensated by blood buffers. Simultaneous increase in expiratory Pco(2), corresponding to the dynamics of acidosis, indicated the existence of respiratory compensation. Sudden increase in acidosis parameters may be the result of lactate accumulation during kidney ischemia. The decreased [HCO(3)(-)] may indicate postreperfusion kidney injury, which must be the subject of further research.

Acid-Base Equilibrium↗