[Risk factors for complications of ureterolithotripsy]

AIM

to determine main risk factors for complications of ureterolithotripsy.

MATERIALS AND METHODS

a retrospective analysis of the results of 545 ureteroscopies performed in 506 patients with ureteral stones over the past 7 years at the urological clinic named after M.F. Vladimirsky was carried out. The relationship between preoperative and intraoperative factors and complications of ureterolithotripsy was analyzed.

RESULTS

The overall complication rate was 22.4%. The risk of intraoperative complications was proved to increase (p<0.05) along with the stone size, location in proximal ureter, stone impaction for more than 3 weeks and the degree of hydronephrosis. No preoperative stenting or nephrostomy tube prior to ureteroscopy was associated to an increased risk of intraoperative complications (RR=2.88; p=0.03). Patients with preoperative drainage of upper urinary tract has lower probability of intraoperative complications (OR=0.35; p=0.03). The risk of developing stricture and ureteral obliteration in uncomplicated ureteroscopy was minimal (RR=0.008, p=0.0001). Small ureteral perforation and pronounced mucosal inflammation around the stone have the similar influence on the risk of complications, which was more than 7.5 times (p=0.0001) higher than in uncomplicated ureteroscopy. Large ureteral perforation was associated with the highest risk of stricture formation and ureteral obliteration, which was 64 times (p=0.0001) higher than in uncomplicated ureteroscopy.

CONCLUSION

The rate of complications of ureterolithotripsy directly depends on the following factors: size and location of the stone, the stone impaction, pre- and intraoperative (nephrostomy tube) drainage of the upper urinary tract, the degree of hydronephrosis, level of bacteriuria and intraoperative trauma complications.

[The choice of method of treatment of patients with stones in ureteropelvic junction]

Stones located in the UPJ are accompanied by the most severe violation of the upper urinary tract urodynamics compared to other localizations of stones, which often leads to severe septic complications requiring emergency care. The study has evaluated the results of treatment of 147 patients with UPJ stones using various methods of treatment, and their efficacy in these patients. Extracorporeal shockwave lithotripsy (ESWL) was performed in 55 patients, contact ureterolithotripsy (CULT)--in 23 patients, percutaneous nephroureterolithotripsy and nephroureterolithoextraction (PCNLT and PCNLE)--in 43 patients, and open surgery (ureterolithotomy, pelviolithotomy)--in 26 patients. The best results in all parameters were obtained from patients with stone size up to 1 cm after ESWL, as well as in patients with stone size greater than 1 cm after PCNLT (PCNLE). In these groups, full discharge of stone at 3 months after treatment was achieved in 95 and 97.7% of patients, respectively. Complications in the ESWL group were recorded in 14.6% of patients, in the PCNLT (PCNLE) group--in 9.2% of patients.

[Retrograde nephrolithotripsy in treatment of staghorn nephrolithiasis]

The article presents the results of 42 retrograde nephrolithotripsy (RNLT) performed on 38 patients with staghorn nephrolithiasis. The staghorn cacculi SN-2 were most frequently indication for the intervention. 3 months after surgery, full exemption of the kidney from the fragments was observed in 85,6% of patients. RNLT is an effective and safe treatment for patients with staghorn stones with relatively low need for additional procedures. RNLT allows to reduce postoperative hospital stay and recovery period of patients.

[Transcutaneous nephrolithotripsy in presenile and senile patients]

A total of 323 transcutaneous roentgenoendoscopic operations were made in 212 patients from January 2000 to December 2009 including 96 operations in 81 presenile and senile patients (87 and 9 operations, respectively). Transcutaneous nephrolithotripsy (TCNT) eliminated concrement from the kidney for one session in 59 (72.8%) patients. It proved to be the most sparing treatment in serious clinical situations and provided maximally complete evacuation of the concrement from the kidney. A total complication rate was 14.8%. All the complications were cured with conservative pharmacotherapy. TCNT has the same indications as open surgery, is a method of choice in presenile and senile patients with large, stag-horn and recurrent concrements of the kidney, impacted pelvicoureteral concrements, in impaired renal urodynamics and high bacteriuria. TCNT can be used as a second-line treatment in failure of extracorporeal shock-wave lithotripsy or in combination with it (sandwich-therapy) for complete concrement elimination.

[Choice of treatment in patients with urolithiasis of anomalous kidneys]

We studied efficacy of transcutaneous nephrolithotripsy (TNLT) in patients with urolithiasis and anomalous upper urinary tract. For two years we performed TNLT in 148 patients with complicated forms of urolithiasis and anomalous kidneys (age 18-86, 76 females and 72 males). The examination for urolithiasis has found different anomalies of the urinary tract in these patients: double pelvis and ureter (9 cases--6.1%), lumbar dystopy of the kideney (59 cases--39.9%), horseshoe kidney (12 cases--8.1%), solitary cyst of the kidney (43 cases--29.0%), parapelvic cysts (25 cases--16.9%). Extracorporeal shock-wave lithotripsy (ESWL) was conducted as first-line treatment in the other 139 patients with nephroliths under 1.5-2 cm in size who had the following anomalies of the urinary system: a solitary kidney (n=14), double pelvis and ureter (n=26), anomalous position of the kidney (n=46), anomalous shape of the kidney (n=20), simple and parapelvic cysts (n=33). A total of 154 TNLT were performed in 148 patients. Transcutaneous interventions were most frequent in the treatment of coral (31.3%) and pelvoureteral (14.6%) concrements, one-stage operation was made in 143 patients. Transcutaneous puncture nephrostomy as the first stage was made in 5 patients. The concrements were removed by one operative intervention in 132 (89.2%) out of 148 patients. Exacerbation of pyelonephritis as a postoperative complication was treated conservatively in 12.5% patients. Residual fragments were diagnosed in 16 patients. Of them, 11 patients had multiple and 5 patients had coral concrements. Residual fragments were removed in 14 patients either by renephroscopy or by ESWL. Treatment of 139 patients with concrements less than 1.5-3 cm in size consisted in 197 ESWL sessions. In combination of anomaly and urolithiasis the number of lithotripsy sessions per one patient was 1.8 +/- 0.2. The least number of ESWL sessions per one patient was conducted in patients with lumbar dystopy of the kidney (1.3 +/- 0.45), the greatest number in horseshoe kidney (3.8 +/- 0.8). Evacuation of the concrements after ESWL depended on the type of anomaly and concrement location. It was 61-69% in patients with anomaly of the shape and position of the kidney, in cystic anomalies is was 89-91%. Open surgery was indicated in 7 patients who needed plastic surgery of hydronephrosis (4) and obstructive megaureter (3). Thus, low-invasive operations provide high efficacy of urolith removal in patients with anomalies of the urinary tract and can replace traumatic open operations.

[Low-invasive techniques in the treatment of urolithiasis with application of innovative equipment made in Russia]

A total of 1100 sessions of extracorporeal shock wave lithotripsy (ESWL) were made in 720 patients with urolithiasis in the last decade with application of LGK-Compact lithotripter which generates shock waves electrodynamically and has no focusing lens. Such lithotriptor allows ESWL in patients with a high anesthesiological risk. Fitting the LGK-Compact lithotriptor with an endourological complex ENDO-MIT tooled for low-invasive interventions under X-ray control enabled treatment of 467 patients with urolithiasis aged 30-80 years. Most of the patients (66.04%) were at the productive age of 18-50 years. ESWL on the LGK-Compact lithotriptor was made in 182 patients (mean number of sessions was 2.1). Six and 12 month follow-up examinations registered complete elimination of the fragments in 169 patients. Thirty-four patients with concrements of the intramural ureter were exposed to 1 to 3 sessions. The fragments eliminated for 1-14 days after the session in 25 patients. Three patients developed stone path which evacuated spontaneously in two cases. For 3 years transcutaneous nephrolithotripsy was conducted in 214 patients. The concrements were removed during one operation in 156 (72.9%) patients, 58 (26.1%) patients had residual fragments. Reoperation was made in 34 patients 7-12 days after the first intervention. In the rest 24 cases (11.2%) residual fragments were removed by means of ESWL on LGK-Compact. Thus, ESWL is a leading technique in management of uncomplicated uroliths maximum 2 cm in size. When indications to ESWL are limited or this method is not effective, the role of roentgenoendoscopic interventions, such as transcutaneous nephrolithotripsy and transurethral contact ureterolithotripsy, takes on special significance. Such clinical innovation as endourological complex ENDO-MIT with lithotripter LGK-Compact made in Russia opens new perspectives of the treatment of urolithiasis and other urological diseases due to introduction of novel highly effective domestic technologies leading to a significant reduction in the number of postoperative complications and time of treatment, to 1.5-2 fold reduction in costs of equipment compared to foreign analogues.

[Coprecipitation of the Pseudomonas fluorescens lipase with hydrophobic compounds as an approach to its immobilization for catalysis in nonaqueous media]

The precipitation of N-cetylamine, N-cetylacetamide, hexan-1,2-diol, cetyl alcohol, and poly(butyl metacrylate) in acetone-water media in the presence of the lipase from Pseudomonas fluorescens was found to be accompanied by the coprecipitation of the enzyme. Within the lyophilized coprecipitates, the lipase exhibits a high catalytic activity and enantioselectivity in the reaction of (1RS)-phenylethanol acetylation with vinyl acetate in t-butyl methyl ether. In order of increasing lipase activity, the coprecipitates can be arranged in the series: cetyl alcohol, poly(butyl metacrylate), hexadecane-1,2-diol, N-cetylamine, and N-cetylacetamide, with the activity 2.5- to 19-fold exceeding the activity of the native enzyme. The immobilization of the lipase on solid supports, such as Celite 545 (physical sorption) and Eupergit C250L (covalent binding), in the presence of hexadecane-1,2-diol was found to increase the esterifying activity of the enzyme. The English version of the paper.

Polymer versus monomer as displacer in immobilized metal affinity chromatography

Successful immobilized metal affinity chromatography (IMAC) of proteins on Cu2+-iminodiacetic acid Sepharose has been carried out in a displacement mode using a synthetic copolymer of vinyl imidazole and vinyl caprolactam [poly(VI-VCL)] as a displacer. Vinyl caprolactam renders the co-polymer with the thermosensitivity, e.g., property of the co-polymer to precipitate nearly quantitatively from aqueous solution on increase of the temperature to 48 degrees C. A thermostable lactate dehydrogenase from the thermophilic bacterium Bacillus stearothermophilus modified with a (His)6-tag [(His)6-LDH] has been purified using an IMAC column. For the first time it was clearly demonstrated that a polymeric displacer [poly(VI-VCL)] was more efficient compared to a monomeric displacer (imidazole) of the same chemical nature, probably due to the multipoint interaction of imidazole groups within the same macromolecule with one Cu2+ ion. Complete elution of bound (His)6-LDH has been achieved at 3.7 mM concentration of imidazole units of the co-polymer (5 mg/ml), while this concentration of free imidazole was sufficient to elute only weakly bound proteins. Complete elution of (His)6-LDH by the free imidazole was achieved only at concentrations as high as 160 mM. Thus, it was clearly demonstrated, that the efficiency of low-molecular-mass displacer could be improved significantly by converting it into a polymeric displacer having interacting groups of the same chemical nature.

Thermosensitive copolymers of N-vinylimidazole as displacers of proteins in immobilised metal affinity chromatography

Synthetic copolymers of N-vinylcaprolactam (VCL) and N-vinylimidazole (VI) were studied as thermosensitive, reusable displacers for immobilised metal affinity chromatography (IMAC) of proteins. The copolymer with weight-average molecular mass of 11700 g/mol prepared by free radical polymerisation at a 9:1 monomer molar ratio was separated into several fractions by IMAC and thermal precipitation. The fraction with an average VI content of 8.5% was most efficient as a reusable displacer for IMAC of ovalbumin, lysozyme and other proteins of egg white on Cu2+-IDA-Sepharose. The displacer exhibited a sharp breakthrough curve and binding capacity of 16-20 mg/ml gel, depending on the flow-rate. The recovery of egg white proteins in the course of displacement chromatography was >95%. The displacer could be removed quantitatively from the protein fractions by thermal precipitation at 48 degrees C. Co-precipitation of lysozyme with the displacer was minimal in the presence of 3% (v/v) acetonitrile, while the lysozyme enzymatic activity in the supernatant was completely retained. Addition of free imidazole to the mobile phase increased the rate of protein desorption and allowed better separation of egg white proteins and the displacer in the course of chromatography. The displacement profile of the egg white extract consisted of three zones with different distributions of individual proteins characterised by SDS-PAGE. Regeneration of the column was easily performed with 0.02 M EDTA in 0.15 M sodium chloride, pH 8.0, followed by washing with distilled water and reloading with Cu2+. The displacer could also be regenerated by thermal precipitation at 48 degrees C and subsequent dialysis against dilute hydrochloric acid (pH 2.5).

[The study of hydrolysis of new lipid-like substrates and trilaurin in monolayers catalyzed with the lipase from Pseudomonas fluorescens]

A simple method for determining the enzymic hydrolysis parameters of lipid-like substrates and trilaurin assembled in monolayers at the water-air interface was suggested. At a surface pressure of 10 mN/m, the initial rates of lipolysis were found to be proportional to the decrease in area of the substrate monolayer caused by the enzymic hydrolysis in a single-compartment Langmuir balance. The kinetic parameters for the hydrolysis of trilaurin and three 1,3-dilaurylpseudoglycerides acetylated in position 2 with an amino acid (phenylalanine, leucine, or valine) catalyzed with lipase from Pseudomonas fluorescens were determined. Unlike models of enzymic hydrolysis that neglect the thickness of the substrate monolayer, our method allows the determination of kinetic parameters in standard dimensions. The values of kcat for the synthetic pseudoglycerides were found to be significantly higher than that for trilaurin, while the values of Km(app) were close. This may be due to the presence of positively charged primary amino groups in the molecules of pseudoglycerides.

[Molecular design of polymeric materials for biotechnology and medicine]

This review describes new polymer materials for biomedical applications developed in the Polymers for Biology Laboratory of the Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences. These include composite rigid sorbents for biochromatography, polymer dispersions for immunoassay, polymer hydrogels for immobilization of enzymes and cells, and polymer ultra thin films as biomembrane models and materials for biosensors. Some general and specific properties of these new materials and models as well as examples of their applications are discussed.

[Extracorporeal lithotripsy in combination with endoscopic papillotomy in choledocholithiasis]

Results of treatment of 30 patients of 50 to 90 years of age having choledocholithiasis by the method of extracorporeal lithotripsy (EL) combined with endoscopic operations on the major duodenal papilla are described. The first stage in the treatment was endoscopic papillosphincterotomy. There were 41 sessions of EL (at an average 1,37 procedure for each patient). In 15 patients spontaneous excretion of the fragments from the common bile duct was noted. The endoscopic sanitation of the common bile duct with a removal of fragments with the Dormia basket was fulfilled in 13 patients after EL. The method of choledocholithotomy proved to be ineffective in 2 patients. Sanitation of the common bile duct was performed in all the patients before their discharge from the hospital. Thus the results obtained allow considering the extracorporeal biliary lithotripsy when combined with endoscopic papillosphincterotomy as an effective method for treatment of patients with choledocholithiasis which not only supplements traditional surgical procedures but also may be used as an alternative method of treatment especially for patients with high operative risk.

Characterization of weak hydrophobic composite sorbents and their application to the isolation of bacterial lectin

Composite sorbents based on wide-pore glass and silica coated with N-butyl polyacrylamide (butyl-PA-glass and butyl-PA-silica) were studied. The surface tension of butyl-PA-silica is 50-55 mJ/m2 as evaluated by the sedimentation volume technique. The linear dependences of log k' on ammonium sulphate concentration were determined by isocratic chromatography of the dipetide Trp-Trp and lysozyme on butyl-PA-glass. Both solutes were shown to have a weaker retention on butyl-PA-glass than on butyl-Toyopearl 650C. This weaker retention is beneficial in the purification of sialic acid-binding lectin from Bacillus subtilis.

Recombinant human insulin. V. Optimization of the reversed-phase high-performance liquid chromatographic separation

The applicability of reversed-phase high-performance liquid chromatography (HPLC) to the analysis of the products of recombinant insulin was studied. The influence of several mobile phases in reversed-phase and ion-pair HPLC on selectivity, resolution and sensitivity was investigated. Optimum conditions for the separation of insulin-related proteins on commercial and laboratory-made supports were established by means of three-dimensional optimizations of selectivity and resolution as a function of pH and ionic strength (mu). A mechanism for the separation of proteins with a mobile phase containing a high salt concentration and a pH near the isoelectric point of proteins is proposed. The questions of scaling up are considered. The proposed techniques allow the analysis of the main impurities and ensures a high quality of active insulin production.

[Genetic engineering of human insulin. IV. Development and optimization of an analysis system using reversed phase high pressure liquid chromatography]

The effectiveness of the RP HPLC application for the step-by-step analysis of the recombinant insulin production was studied. Properties of a number of commercial and experimental columns in different chromatographic conditions were considered. A three-dimension optimization of selectivity and resolution versus pH and ion strength was carried out. A mechanism of the resolution and selectivity control is suggested.

[Autoradiographic characteristics and negative effects of radionuclide elimination from the body using sorbents]

It is shown that 210Po in the complex with a sorbent can be fixed in the organs, particularly in the proximal renal tubules. This, in the authors' opinion, can be the cause of various complications of the therapy with the adsorbents including the development of tumours.

Synthesis of polymeric neoglycoconjugates based on N-substituted polyacrylamides

Several types of polymeric glycoconjugates, N-substituted polyacrylamides, have been synthesized by the reaction of activated polymers with omega-aminoalkylglycosides: (i) (carbohydrate-spacer)n-polyacrylamide, 'pseudopolysaccharides'; (ii) (carbohydrate-spacer)n-phosphatidylethanolaminem-polyacrylamide, neoglycolipids, derivatives of phosphatidylethanolamine; (iii) (carbohydrate-spacer)n-biotin-polyacrylamide, biotinylated probes; (iv) (carbohydrate-spacer)n-polyacrylamide-(macroporous glass), affinity sorbents based on macroporous glass, covalently coated with polyacrylamide. An almost quantitative yield in the conjunction reaction makes it possible to insert in the conjugate a predetermined quantity of the ligand(s). Pseudopolysaccharides proved to be a suitable form of antigen for activation of polystyrene and poly(vinyl chloride) plates (ELISA) and nitrocellulose membranes (dot blot), being advantageous over traditional neoglycoproteins. Polyvalent glycolipids insert well in biological membranes: their physical properties, particularly solubility, can be changed in a desired direction. Biotinylated derivatives were used as probes for detection and analysis of lectins.

[Genetically engineered human insulin. 1. HPLC in analyzing products of basic production stages]

Application of some variants of HPLC for the step-by-step analysis of recombinant human insulin production was studied. Chromatographic columns with commercial and specially developed supports for size-exclusion, ion-exchange and reverse phase HPLC were used. Effective combinations of the chromatographic techniques for analysis of products and intermediates at every technological step were found and used for production of insulin. The authenticity of insulin obtained in the Shemyakin Institute of Bio-organic Chemistry by the scheme described in the present paper was confirmed by means of some physical and chemical methods and biological activity analysis.

Favourable biospecific reactivity of blood group B antigenic trisaccharide chemically attached to poly-N-(2-hydroxyethyl)acrylamide-coated porous glass

Blood group B antigenic trisaccharide-beta-aminopropyl glycoside (B-TSAP) covalently attached to poly-N-(2-hydroxyethyl)acrylamide-coated porous glass interacts with anti-B monoclonal antibodies faster than the ligand coupled to CNBr-activated Sepharose 4B and Affi-Gel 10. Rates of hydrophobic adsorption of antibodies on the butyl derivatives of the same supports were measured to evaluate the diffusion input to overall kinetics. The lowest average affinity adsorption time [t1(aff) = 250 s] observed for polymer-coated glass probably arises because of the flexibility of the extended segments of chemisorbed N-substituted polyacrylamide acting as effective spacer arms.

Inorganic supports coated with N-substituted polyacrylamides: application to biospecific chromatography of proteins

Wide porous glass (WPG) chemically coated with a poly-N-(2-hydroxyethyl)acrylamide layer is proposed as a carrier of biospecific ligands in affinity chromatography. The method of WPG chemical modification includes synthesis of the gamma-aminopropyl derivative followed by chemical adsorption of poly(p-nitrophenyl acrylate). Ester groups of the polyacrylate-coated WPG can be used for coupling the ligands bearing primary amino groups. Condensation of esters with ethanolamine yields a poly-N-(2-hydroxyethyl)acrylamide-coated support with non-specific adsorption properties resembling those of Sepharose 4B. Human IgG immobilized on the polyacrylate support was used for isolation of the first complement component from human serum and for its separation into subcomponents C1r, C1s and C1q by a one-step method. An unbound part of serum may be used as the R1 reagent for determining haemolytic C1 activity. The stepwise elution of C1r, C1s and C1q from the column reflects the course of C1 breakdown after its activation on immune complex formation.

[Diagnosis of osteomalacia using dynamic scintigraphy with diphosphonate in terminal renal insufficiency]

In the diagnosis of osteomalacia in patients with terminal renal insufficiency after the method of dynamic scintigraphy with diphosphonate major emphasis should be placed on the coefficient of RP blood elimination (C1). The disease should be diagnosed in C1 below 0.1 min.-1. A relative increase in the coefficient of cumulative RP in the bones (C2) as compared to C1 (greater than 2-fold) should be regarded an accessory sign in the diagnosis of osteomalacia.

[The development of methods for obtaining monospecific ingredients for immunoenzyme analysis]

The methods of the modification of Salmonella O- and H-antigens and the preparation of biologically active sorbents on their basis have been developed. The use of these sorbents has permitted the isolation of affinity antibodies with strictly defined specific activity. The work shows the possibility of the successful use of carriers obtained on the basis of porous glass, chemically modified by acrylic copolymers containing activated carboxylic groups, and intended for the immobilization of antigens of both protein and carbohydrate nature.

[Pathomorphology of the results of chronic irradiation from a gamma-neutron source implanted in the abdominal cavity]

Comparison of the results of morphological investigations of the internal organs of dogs and sheep with gamma-neutron radiation sources, implanted in the abdominal cavity, has shown that the correlation between a degree of severity and type of morphological changes in this case is similar to that of identical irradiation from an external source.

[Morphometric research in determining the absorbed dose in the lungs formed from aspirated radionuclides]

Macro- and microtopography of the distribution of aspirated colloidal 144CeF3 in autographs of rabbit lung total sections were examined with the help of a monitoring-measuring device "Videoplan" and microcomputer. Quantitative assessment of photoemulsion-blackening areas at the site of radionuclide concentration has confirmed that aspirated radionuclides are distributed in the lungs according to the same laws as nonradioactive aerosols: the relation of total microvolumes of actually irradiated pulmonary tissue to the entire lung volume long after radionuclide entry is shown; a possibility to use these data for determination of an actually absorbed dose in microvolumes of pulmonary tissue during aspiration of radionuclides is considered.

[Polymer-modified silica sorbents for molecular sieve chromatography of biopolymers]

N-vinylpyrrolidone-N(2-hydroxy) acrylamide copolymer-modified porous glass was studied as a support for gel permeation chromatography. Influenza, Sendai, fowl plague viruses and rota-viruses were purified by chromatography on the support. As compared with Sepharose 4B the support shows better hydrodynamic properties and yields higher amounts of purified viruses. The support can be also applied to the t-RNA and ribosomes separation.

[Binding and activation of the first component of human complement on artificial matrices]

Artificial sorbents that comprise macroporous glass covered by the copolymer of N-vinylpyrrolidone and N-substituted acrylamide have been synthesized. Aminoethanol is bound to acrylic acid residue in one sorbent (AE-glass), whereas the other sorbent involves immunoglobulin G with the hexamethylenediamine spacer (IgG-glass). C1q binds specifically to IgG-glass with Ka 4,07(+/- 0,32) X 10(7) M-1. Free energy of the C1q binding to IgG-glass is twice higher than that of its binding to monomeric IgG. This evidences that one C1q molecule associates with two IgG molecules of the sorbent. A weak nonspecific sorption of C1q to AE-glass was found. Both specific (on IgG-glass) and nonspecific (on AE-glass) sorption of the first component of complement activate the classical pathway in human serum as manifested in the consumption of the C4, C2, C3 and C5 components. IgG-glass was employed for C1q isolation from human serum by affinity chromatography, whereas unbound part of serum may be used as a reagent R1q. The yield of highly purified C1q after IgG-glass affinity chromatography and gel filtration on Sephacryl S-300 is 63,6%.

[Pathomorphologic changes in the testes of rats fed gamma ray irradiated products]

A study was made of morphological changes in the testes of 120 rats fed for 20 months only food exposed to gamma-rays. Pronounced alterative-dystrophic disorders up to foci of coagulation necrosis and aspermatogenesis as well as compensatory-adaptation processes such as proliferation of Leydig cells were found. A direct correlation was disclosed between the severity of structural alterations in the testes and the dose of gamma-rays to which the products used for animals' feeding had been exposed. A suggestion is made about the autoimmune mechanism of structural alterations discovered.

[pH dependence of tryptophan ethyl ester hydrolysis]

The dependence of the rate of spontaneous hydrolysis of tryptophan ethyl ester within a wide range of pH (4,6-10,3) was studied. This dependence was found to differ from other dependences, i.e. within the pH range of 4,6-7,0 the value of the rate constant is practically independent on pH. In order to describe the dependence obtained a general pattern of hydrolysis was postulated and the kinetic parameters of individual elementary reactions were determined. The rate constants for the hydrolysis of the amino acid with a non-protonated amino group of ester was calculated using the literary values for the rate constants of carboxylic acid hydrolysis. The obtained values of the second order rate constants for the alkaline hydrolysis of non-protonated and protonated forms of tryptophane ester (k4 and k5) are 1,1 and 79 M-1 s-1, respectively; those for the hydrolysis of the protonated form of the substrate (k3) are 1,0.10(-5) M-1 s-1. The role of spontaneous (non-enzymatic) hydrolysis in stereoselective cleavage of amino acid esters is discussed.

[Reconstruction of the tubular epithelium of allotransplanted kidneys of man in late periods following transplantation]

The structure of allotransplanted kidneys (AK) from human cadavers that remained in the recipient's body for a long time (4 months-6 years) has been studied. AK that preserved good function up to the patient's death not consequent on the transplant insufficiency showed a weak immunocellular connective tissue, with the epithelium of proximal canaliculi being cytologically reconstructed. The reconstruction lay in formation of numerous polykaryocytes having a hypertrophied brush-like outline. This phenomenon ("proximal polykaryocytosis") is assessed as a manifestation of regeneratory potencies of the epithelium of AK proximal tubules in late periods after transplantation. Chronic moderate hypoxia of AK was conducive to reconstruction of the epithelium of the nephron proximal part. Inadequate function of AK was related to the development of chronic rejection resistant to the treatment, and AK demonstrated an intensive immunocellular reaction and developed gross sclerosis that produced atrophy of most AK tubular.

[Renal pathomorphology of rats fed irradiated food products over a long period]

Morphological changes were studied in the kidneys of albino rats and their progeny fed only with irradiated food for 20 months. Morphological signs of the autoimmune process in the form of the membraneous-proliferative glomerulonephritis in combination with characteristic disturbances of the blood vessels and extensive lymphoid-histiocyticeosinophilis infiltration of the stroma were revealed.