Alterations in the chromatin packaging, driven by transcriptional activity, revealed by AFM

BACKGROUND

The gene expression differs in the nuclei of normal and malignant mammalian cells, and transcription is a critical initial step, which defines the difference. The mechanical properties of transcriptionally active chromatin are still poorly understood. Recently we have probed transcriptionally active chromatin of the nuclei subjected to mechanical stress, by Atomic Force Microscopy (AFM) [1]. Nonetheless, a systematic study of the phenomenon is needed.

METHODS

Nuclei were deformed and studied by AFM. Non-deformed nuclei were studied by fluorescence confocal microscopy. Their transcriptional activity was studied by RNA electrophoresis.

RESULTS

The malignant nuclei under the study were stable to deformation and assembled of 100-300 nm beads-like units, while normal cell nuclei were prone to deformation. The difference in stability to deformation of the nuclei correlated with DNA supercoiling, and transcription-depended units were responsive to supercoils breakage. The inhibitors of the topoisomerases I and II disrupted supercoiling and made the malignant nucleus prone to deformation. Cell nuclei treatment with histone deacetylase inhibitors (HDACIs) preserved the mechanical stability of deformed malignant nuclei and, at the same time, made it possible to observe chromatin decondensation up to 20-60 nm units. The AFM results were supplemented with confocal microscopy and RNA electrophoresis data.

CONCLUSIONS

Self-assembly of transcriptionally active chromatin and its decondensation, driven by DNA supercoiling-dependent rigidity, was visualized by AFM in the mechanically deformed nuclei.

GENERAL SIGNIFICANCE

We demonstrated that supercoiled DNA defines the transcription mechanics, and hypothesized the nuclear mechanics in vivo should depend on the chromatin architecture.

Bifractal structure of chromatin in rat lymphocyte nuclei

The small-angle neutron scattering (SANS) on the rat lymphocyte nuclei demonstrates the bifractal nature of the chromatin structural organization. The scattering intensity from rat lymphocyte nuclei is described by power law Q^{-D} with fractal dimension approximately 2.3 on smaller scales and 3 on larger scales. The crossover between two fractal structures is detected at momentum transfer near 10^{-1}nm^{-1}. The use of contrast variation (D_{2}O-H_{2}O) in SANS measurements reveals clear similarity in the structural organizations of nucleic acids (NA) and proteins. Both chromatin components show bifractal behavior with logarithmic fractal structure on the large scale and volume fractal with slightly smaller than 2.5 structure on the small scale. Scattering intensities from chromatin, protein component, and NA component demonstrate an extremely extensive range of logarithmic fractal behavior (from 10^{-3} to approximately 10^{-1}nm^{-1}). We compare the fractal arrangement of rat lymphocyte nuclei with that of chicken erythrocytes and the immortal HeLa cell line. We conclude that the bifractal nature of the chromatin arrangement is inherent in the nuclei of all these cells. The details of the fractal arrangement-its range and correlation/interaction between nuclear acids and proteins are specific for different cells and is related to their functionality.

[Left ventricular myocardial hypertrophy after transplantation of the kidney: risk factors and possible regress]

AIM

To study structural-functional changes in left ventricular (LV) myocardium in recipients of renal allograft (RA) after different postoperative period and to specify factors promoting persistence, progression or regression of LV hypertrophy (LVH).

MATERIAL AND METHODS

The study included 240 recipients of primary RA (38% females and 62% males, age 16-69 years, mean age 42 +/- 11 years). A prospective study covered 143 patients.

RESULTS

LVH was diagnosed in 52% patients. LVH incidence after renal transplantation (RT) had a wave-like dynamics: during 9 months after RT LVH presents in more than 50% patients; after 9-24 months after the operation it fell to 30% and after 3-7 years after the operation it affected at least 2/3 patients. After RT LVH risk factors were age, duration of chronic renal failure (CRF) and pretransplantation dialysis, reduced mass of the operating nephrons, arterial hypertension, anemia, functioning of arterio-venous fistula (AVF) and chronic inflammation syndrome. LVH was also associated with factors specific for RT: RA rejection crises, infections complicating massive immunosuppressive therapy. LVH is also associated with proteinuria which may indicate RA damage and can be considered as a marker of generalized endothelial dysfunction. 2-year and longer follow-up after RT confirmed complete LVH regression in 1/3 of the recipients. LVH regression was observed in normal RA function, normal blood pressure, the absence of proteinuria, hypoalbuminemia, anemia, AVF, infectious complications.

CONCLUSION

LVH after RT is multifactorial and can completely regress in a favourable posttransplantation course.

[Replacement renal therapy in complex treatment of severe acute pancreatitis]

The purpose of this study was to retrospectively analyze the efficiency of replacement renal therapy (RRT) in multimodality treatment for severe acute pancreatitis (SAP) concurrent with a systemic inflammatory response and multiple organ failure/dysfunction. The authors analyzed the results of treating 55 patients (14 women and 41 men) aged 22 to 72 years (mean 43.5 +/- 16.4 years) treated at the intensive care units of Moscow City Clinical Hospital Fifty-Two in January 1, 2000, to December 31, 2006. All the patients had multiple organ dysfunctions with the involvement of 2 to 5 organs (median 4 (3; 4) and were on RRT. RRT may be successfully used in multimodality treatment for SAP provided that the dose of dialysis is at least 35 ml/kg/hour. The severe condition rated by the APACHE HII and SAPS II scales and the dialysis dose of less than 35 ml/kg/hour are independent risk factors of death in SAP patients.

[Rapidly progressive glomerulonephritis in ANCA-associated vasculitis: a course, treatment efficacy, prognosis]

AIM

To study efficacy of ANCA-RPGN treatment with corticosteroids and cyclophosphamide or mycophenolic acid drugs.

MATERIAL AND METHODS

We treated 28 patients (17 males and 11 females aged 19-71 years) with morphologically verified ANCA-associated crescentic RPGN (crescentic median 79 (63:88)%. The patients received corticosteroids and cytostatics.

RESULTS

The response to the treatment was registered in 22 (78%) patients in 8-16 weeks: a complete remission was achieved in 8 patients, a partial one--in 14 patients. In partial remission renal functions recovered incompletely (median Pcr 200 (180;255) mcmol/l) in persistence of moderate proteinuria (median 0.7 (0.6;1.3)g/day) and absence of microhematuria. Probability of the treatment success depended on severity of glomerulosclerosis and weakly depended on activity of extracapillary reaction. Severe renal failure was not an absolute predictor of treatment failure.

CONCLUSION

In the absence of advanced nephrosclerosis early treatment with corticosteroid in combination with cytostatics can produce a positive effect in 70-80% patients with ANCA associated RPGN.

What can comparative genomics tell us about species concepts in the genus Aspergillus?

Understanding the nature of species" boundaries is a fundamental question in evolutionary biology. The availability of genomes from several species of the genus Aspergillus allows us for the first time to examine the demarcation of fungal species at the whole-genome level. Here, we examine four case studies, two of which involve intraspecific comparisons, whereas the other two deal with interspecific genomic comparisons between closely related species. These four comparisons reveal significant variation in the nature of species boundaries across Aspergillus. For example, comparisons between A. fumigatus and Neosartorya fischeri (the teleomorph of A. fischerianus) and between A. oryzae and A. flavus suggest that measures of sequence similarity and species-specific genes are significantly higher for the A. fumigatus - N. fischeri pair. Importantly, the values obtained from the comparison between A. oryzae and A. flavus are remarkably similar to those obtained from an intra-specific comparison of A. fumigatus strains, giving support to the proposal that A. oryzae represents a distinct ecotype of A. flavus and not a distinct species. We argue that genomic data can aid Aspergillus taxonomy by serving as a source of novel and unprecedented amounts of comparative data, as a resource for the development of additional diagnostic tools, and finally as a knowledge database about the biological differences between strains and species.

[Risk factors and pathogenetic mechanisms of left ventricular hypertrophy in progressive chronic kidney disease and after transplantation of the kidney]

AIM

To specify the trend in the incidence of left ventricular hypertrophy (LVH) at a predialysis stage of chronic kidney disease (CKD) in the course of its progression from stage III to stage V and after transplantation of the kidney (TK); to study correlations between homeostatic disorders caused by CKD progression and myocardial remodeling; to define the role of some hemodynamic and nonhemodynamic factors in formation of LVH.

MATERIAL AND METHODS

The study enrolled 128 patients (58 males and 70 females, age 18-55 years, mean age 42 +/- 11 years) at a predialysis stage of CKD (group 1) and 225 recipients of renal allotransplant--RRA (group 2, 140 males and 85 females, age 18-69 years, mean age 43 +/- 12 years). General clinical examination, biochemical and immunological blood tests, echocardiography were made.

RESULTS

At a predialysis stage of CKD, LVH was diagnosed in 56% patients. Incidence of LVH was directly related with age of the patients (p = 0.001), blood pressure (p < 0.001), duration of arterial hypertension (p = 0.004), severity of anemia (p = 0.017), the level of C-reactive protein (p = 0.003), blood phosphorus concentration and inversely correlated with glomerular filtration rate--GFR (p = < 0.001), albumin level (p = 0.023) and blood Ca (p < 0.001). LVH was followed up for 12 months in 35 patients with predialysis CKD. Factors of LVH progression and factors hindering its regression were systolic blood pressure, Hb and Ca in the blood. In group 2 of RRA incidence of LVH was 53%. Significant factors of LVH risk after transplantation were age (p = 0.002), hypertension (p = 0.005) and anemia (p = 0.04). Moreover, LVH closely correlated with proteinuria (p < 0.03), transplant dysfunction (p = 0.002) and posttransplantation ischemic heart disease (p < 0.037). Changes in LVH were analysed in 30 RRA. Frequency of LVH decreased for 2 years after transplantation (from 56 to 32%) but 36-60 and more months after transplantation it increased (46 and 64%, respectively). Transplant dysfunction was the leading factor hindering LVH regression after transplantation.

CONCLUSION

The same mechanisms are involved in LVH pathogenesis after transplantation and at a predialysis stage of CKD. The significance of initial renal lesion signs--minimal proteinuria and hypercreatininemia--was higher after renal transplantation than in patients with CKD.

[A renoprotective effect of enalapril in chronic transplantation nephropathy]

AIM

To study safety and efficacy of ACE inhibitor enalapril in chronic transplantation nephropathy (CTN) as well as nephroprotective efficacy of this drug in various clinical variants of CTN.

MATERIAL AND METHODS

A retrospective study covered 220 recipients with CRF. The patients were divided into the study group (n = 103) and the control group (n = 117). The study group was given ACE inhibitor enalapril the efficacy of which was assessed by arterial pressure (systolic, diastolic, mean) dynamics, 24 h proteinuria and the rate of CTN progression. This rate was suggested by probability of plasm creatinin doubling (Kaplan-Meier technique).

RESULTS

Enalapril significantly inhibited CTN progression running with minimal or marked proteinuria, had a pronounced hypotensive effect, promoted stabilization of minimal proteinuria (in CTN with minimal proteinuria) or reduction of protein excretion (in a proteinuric variant of CTN).

CONCLUSION

Use of enalapril in CTN in a daily dose 10 mg maximum is safe and can be used for inhibition of CTN progression.

Sodium ion cycle in bacterial pathogens: evidence from cross-genome comparisons

Analysis of the bacterial genome sequences shows that many human and animal pathogens encode primary membrane Na+ pumps, Na+-transporting dicarboxylate decarboxylases or Na+ translocating NADH:ubiquinone oxidoreductase, and a number of Na+ -dependent permeases. This indicates that these bacteria can utilize Na+ as a coupling ion instead of or in addition to the H+ cycle. This capability to use a Na+ cycle might be an important virulence factor for such pathogens as Vibrio cholerae, Neisseria meningitidis, Salmonella enterica serovar Typhi, and Yersinia pestis. In Treponema pallidum, Chlamydia trachomatis, and Chlamydia pneumoniae, the Na+ gradient may well be the only energy source for secondary transport. A survey of preliminary genome sequences of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, and Treponema denticola indicates that these oral pathogens also rely on the Na+ cycle for at least part of their energy metabolism. The possible roles of the Na+ cycling in the energy metabolism and pathogenicity of these organisms are reviewed. The recent discovery of an effective natural antibiotic, korormicin, targeted against the Na+ -translocating NADH:ubiquinone oxidoreductase, suggests a potential use of Na+ pumps as drug targets and/or vaccine candidates. The antimicrobial potential of other inhibitors of the Na+ cycle, such as monensin, Li+ and Ag+ ions, and amiloride derivatives, is discussed.

The COG database: new developments in phylogenetic classification of proteins from complete genomes

The database of Clusters of Orthologous Groups of proteins (COGs), which represents an attempt on a phylogenetic classification of the proteins encoded in complete genomes, currently consists of 2791 COGs including 45 350 proteins from 30 genomes of bacteria, archaea and the yeast Saccharomyces cerevisiae (http://www.ncbi.nlm.nih. gov/COG). In addition, a supplement to the COGs is available, in which proteins encoded in the genomes of two multicellular eukaryotes, the nematode Caenorhabditis elegans and the fruit fly Drosophila melanogaster, and shared with bacteria and/or archaea were included. The new features added to the COG database include information pages with structural and functional details on each COG and literature references, improvements of the COGNITOR program that is used to fit new proteins into the COGs, and classification of genomes and COGs constructed by using principal component analysis.

Inactivation of Pasteurella (Mannheimia) haemolytica leukotoxin causes partial attenuation of virulence in a calf challenge model

The leukotoxin of Pasteurella (Mannheimia) haemolytica is believed to play a significant role in pathogenesis, causing cell lysis and apoptosis that lead to the lung pathology characteristic of bovine shipping fever. Using a system for Cre-lox recombination, a nonpolar mutation within the lktC transacylase gene of the leukotoxin operon was created. The lktC locus was insertionally inactivated using a loxP-aph3-loxP cassette, and then the aph3 marker was excised from the chromosome by Cre recombinase expressed from a P. haemolytica plasmid. The resulting lktC strain (SH2099) secretes inactive leukotoxin and carries no known antibiotic resistance genes. Strain SH2099 was tested for virulence in a calf challenge model. We inoculated 3 x 10(8) or 3 x 10(9) CFU of wild-type or mutant bacteria into the lungs of healthy, colostrum-deprived calves via transthoracic injection. Animals were observed for clinical signs and for nasal colonization for 4 days, after which they were euthanized and necropsied. The lower inoculum (3 x 10(8) CFU) caused significantly fewer deaths and allowed lung pathology to be scored and compared, while the 3 x 10(9) CFU dose of either the wild-type or mutant was lethal to >/=50% of the calves. The estimated 50% lethal dose of SH2099 was four times higher than that of the wild-type strain. Lung lesion scores were reduced twofold in animals inoculated with the mutant, while clinical scores were nearly equivalent for both strains. The wild-type and mutant strains were equally capable of colonizing the upper respiratory tracts of the calves. In this study, the P. haemolytica lktC mutant was shown to be less virulent than the parent strain.

[Histomorphological tubulointerstitial changes in progression of chronic glomerulonephritis]

The role of histological changes associated with primary types of glomerulonephritides in progression of chronic glomerulonephritis (CGN) is analysed. It is shown that CGN progression acceleration occurs much more frequently if chronic renal failure arises within 7 years since the disease onset, in the presence of concomitant tubulointerstitial changes (TIC)in unfavorable morphological types--mesangiocapillary glomerulonephritis and focal-segmental hyalinosis/ sclerosis. It was found that more frequent occurrence of CGN accelerated progression in unfavorable morphological types and TIC depends on the presence of unfavorable clinical types--active nephritic and nephrotic-hypertensive types (classification of M. Ya. Ratner et al.). In TIC there were primarily unfavorable clinical types which contribute to accelerated progression of CGN. This relationship is explained by involvement of factors belonging to the above clinical types in the mechanism of the morphological changes. In these clinical types CGN accelerated progression takes place irrespectively of the presence of TIC and unfavorable morphological types.

[Prediction of accelerated progression of chronic glomerulonephritis basing on clinical and histomorphological data]

AIM

To find out predictive value of three factors in progression of chronic glomerulonephritis (CGN): unfavorable clinical course, unfavorable morphological type and tubulointerstitial changes.

MATERIALS AND METHODS

150 CGN patients entered the trial. Frequency of onset of chronic renal failure (CRF) within 7 years after the diagnosis was chosen as a criterium of accelerated progression of CGN (AP CGN). Chi-square criterium was used for testing relationships between AP CGN and the parameters under study.

RESULTS

The findings support previously published data on statistically more frequent occurrence of AP CGN in unfavorable clinical types (active nephritic and nephrotically-hypertensive), in unfavorable morphological types (mesangiocapillary CGN and focal-segmental hyalinosis/sclerosis and tubulointerstitial lesions). In unfavorable clinical types there was a significantly more frequent occurrence of AP CGN irrespective of unfavorable morphological changes. In contrast, both in unfavorable and favorable clinical types, frequency of AP CGN in unfavorable morphological types of CGN and tubulointerstitial changes was the same.

CONCLUSION

Clinical type of CGN is a valuable prognostic criterium for AP CGN.

[Implication of clinical and morphological types of chronic glomerulonephritis, tubulointerstitial changes in prognosis of disease progression]

A highly significant relationship has been established between rapid progression of chronic glomerulonephritis and belonging to unfavorable category of clinical types according to classification of M. Ya. Ratner et al. (chi-square = 84.3, p < 0.001), to unfavorable category of morphological types (chi-square = 13.2, p < 0.01) and the presence of tubulointerstitial changes (chi-square = 32, p < 0.0001).

[The importance of a new classification of chronic glomerulonephritis for determining the prognosis of the disease]

Dependence of chronic glomerulonephritis upon its clinical type was studied on the basis of observation in 165 patients of chronic renal failure incidence during 7 years after the beginning of the disease.

[Prognostic factors of chronic glomerulonephritis and chronic non-inflammatory glomerulopathies rapid progression]

AIM

To determine relationships between prognosis of rapid progression of chronic glomerulonephritis (CGN), chronic non-inflammatory glomerulopathies (CNG) with development of chronic renal failure and clinical, morphological types of the disease and tubulointerstitial component (TIC).

MATERIALS AND METHODS

137 CGN and CNG patients were followed up for 7 years. Favorable clinical types were found in 89, unfavorable ones in 48 patients. Favorable and unfavorable morphological types occurred in 87 and 50 patients, respectively. TIC was identified in 56 patients.

RESULTS

Rapid progression of CGN and CNG appeared to associate with the unfavorable clinical type (active nephritic types of CGN and nephrotic-hypertensive type of CNG), the unfavorable morphological type (mesangiocapillary glomerulonephritis and focal segmentary sclerosis/hyalinosis) and TIC.

CONCLUSION

Prognosis of rapid progression of CGN and CNG is most reliable in combination of the above three predictors or of the unfavorable clinical type with TIC.

[The dependence of the progression of chronic glomerulonephritis on the clinical and morphological types of glomerulonephritis and on the tubulointerstitial changes]

Progression of chronic glomerulonephritis (CGN) is strongly associated with morphologic type of the disease, tubulointerstitial changes, some clinical syndromes. The aim of the study was to trace relations between the onset of chronic renal failure within 7 years since the diagnosis (fast progression of CGN--FP CGN), CGN clinical variant according to M. Ia. Ratner et al. classification (1987) and histomorphological changes in the renal biopsy. Unfavorable clinical types (active nephritic types and nephrotic-hypertensive type) proved dominating predictor of FP CGN not only because of close relationship between these type and FP CGN but also due to FP CGN occurrence in morphologically unfavorable morphological types and tubulointerstitial changes in line with concomitant unfavorable clinical types.

[The prognostic significance of the morphological type of chronic glomerulonephritis and of the tubulointerstitial changes depending on the clinical type of the disease]

The review of 200 cases of chronic glomerulonephritis (CG) led the authors to the conclusion that there is a statistically significant relationship between rapid progression (RP) of the disease (onset of chronic renal failure within 7 years since the diagnosis) and its morphological type (chi 2 = 37), tubulointerstitial changes (chi 2 = 34; p < 0.0000), clinical disease types according to M. Ia. Ratner, V. V. Serov et al. (chi 2 = 115; p < 0.0000). In both prognostically favourable and unfavorable morphological types RP occurred more frequently in concurrent unfavorable clinical types (chi 2 = 19; p < 0.0001). In prognostically unfavorable morphological types there were, as a rule, unfavorable clinical types, whereas in favorable ones-favorable clinical types. In the presence of tubulointerstitial changes RP occurred primarily in unfavorable clinical types which are encountered in these morphological changes significantly more frequently than in their absence (chi 2 = 48; p < 0.01). RP of CG in prognostically unfavorable morphological types and tubulointerstitial changes depends mainly on accompanying clinical types of CG.

Generation of targeted nonpolar gene insertions and operon fusions in Pasteurella haemolytica and creation of a strain that produces and secretes inactive leukotoxin

An efficient method for targeted gene inactivation and generation of chromosomal gene fusions in Pasteurella haemolytica has been devised and used to create an lktC::cat operon fusion by allelic exchange at the leukotoxin gene cluster (lktCABD). A copy of the lktC gene was insertionally inactivated by using a nonpolar, promoterless cat cassette and then delivered into P. haemolytica on a shuttle vector. Plasmid incompatibility was used to detect clones where double recombination events had occurred at the chromosomal locus. The insertion in lktC did not affect expression of the downstream genes, and the mutant strain secreted an antigenic proleukotoxin that was neither leukotoxic nor hemolytic. Expression of the lktC gene in trans restored the wild-type phenotype, confirming that LktC is required for activation of the proleukotoxin to the mature leukotoxin. Construction of the lktC::cat operon fusion allowed us to quantitate leukotoxin promoter activity in P. haemolytica and to demonstrate that transcription was maximal during early logarithmic growth phase but was reduced following entry into late logarithmic phase. This allelic exchange system should be useful for future genetic studies in P. haemolytica and could potentially be applied to other members of Haemophilus-Actinobacillus-Pasteurella family, where genetic manipulation is limited.

[The tubulointerstitial changes in different clinical and morphological types of chronic glomerulonephritis]

As shown by the data available on 228 patients with chronic glomerulonephritis, tubulointerstitial alterations (TIA) occur primarily in mesangiocapillary glomerulonephritis, focal-segmental glomerular hyalinosis/sclerosis, diffuse fibroplastic glomerulonephritis as well as in active nephritic and nephrotic-hypertensive types. In 186 patients with chronic glomerulonephritis chronic renal insufficiency evidencing enhanced progression (EP) if arose within 7 years since the disease onset in the presence of TIA was registered significantly more frequently. TIA patients demonstrated EP as a rule in prognostically unfavorable active nephritic and nephrotic-hypertensive types. The relationship between TIA and EP may be explained by their association with unfavourable clinical types suggesting poor prognosis.

Plasmids for heterologous expression in Pasteurella haemolytica

New cloning and expression vectors that replicate both in Pasteurella haemolytica and in Escherichia coli were constructed based on a native sulfonamide (SuR) and streptomycin (SmR) resistant plasmid of P. haemolytica called pYFC1. Each shuttle vector includes an MCS and a selectable antibiotic resistance marker that is expressed in both organisms. Plasmid pNF2176 carries the P. haemolytica ROB-1 beta-lactamase gene (blaP, ApR) and pNF2214 carries the Tn903 aph3 kanamycin resistance (KmR) element. The expression vector, pNF2176, was created by placing the MCS downstream of the sulfonamide gene promoter (PsulII) on pYFC1; this was used to clone and express the promoterless Tn9 chloramphenicol resistance gene (cat, CmR) in P. haemolytica (pNF2200). A promoter-probe vector (pNF2283) was constructed from pNF2200 by deleting PsulII.

Escherichia coli strain for thermoinducible T7 RNA polymerase-driven expression

An Escherichia coli strain for thermoinducible T7Pol-driven transcription has been constructed. The strain was obtained by site-specific integration of the T7 gene 1 coding for T7Pol into the attB site of phage lambda in the E. coli chromosome. The expression of the inserted gene is regulated by cIts857 and major early promoter-operator regions of phage lambda.

[A clinico-morphological analysis of the efficacy of therapy in chronic glomerulonephritis using prednisone, a cytostatic, an anticoagulant and an antiaggregant]

Four-component therapy (chlorbutin 0.2 mg, prednisone [correction of prednisolone] 60 mg, curantyl 400 mg/day per os, i.v. heparin 10,000 U twice a day) was given for 9-36 months to 76 patients with chronic glomerulonephritis (CGN). A statistically significant lowering of proteinuria was achieved irrespective of CGN clinicomorphological variant. As indicated by remission frequency and normalization of urinary osmotic concentration, efficacy of the above treatment is related to a clinical CGN type. Because clinical and morphological CGN types are correlated, the disease morphology and treatment effect are associated. The treatment proved effective in nephrotic mesangioproliferative, mesangiocapillary glomerulonephritis, focal-segmental glomerular sclerosis, active nephritic mesangiocapillary glomerulonephritis and inactive nephritic mesangioproliferative and mesangiocapillary glomerulonephritis. Nephrotic-hypertonic focal-segmental glomerulosclerosis and mesangiocapillary glomerulonephritis were resistant to therapy.

[Cosmid libraries containing DNA from human chromosome 13]

We characterized two cosmid libraries constructed from flow-sorted chromosome 13 at the Imperial Cancer Research Fund (ICRF), UK (13,000 clones) and Los Alamos National Laboratory (LANL), USA (17,000 clones). After storage for two years, clones showed high viability (95%) and structural stability. EcoR I and Hind III restriction patterns were studied in more than 500 ICRF and 200 LANL cosmids. The average size of inserts was shown to be 35-37 kb in both the libraries. Most cosmids (83% and 93% of ICRF and LANL libraries, respectively) exceed the lower size limit of DNA fragments that can be packaged and represent a good source for physical mapping of chromosome 13. Total length of inserts is four and five genome equivalents in the ICRF and LANL libraries, respectively. ICRF cosmids showed hybridization to 22 of 24 unique probes tested, which corresponds to a 90% probability of having any DNA fragment represented in the library. More than 1 Mb of chromosome 13 is overlapped by 90 cosmids of 22 groups revealed. A chromosomal region of more than 150 kb, containing the ATP1AL1 gene for alpha-1 peptide of Na+, K(+)-ATPase, is covered by 12 cosmids forming a contig. The results of restriction and hybridization analyses are stored in a CLONE database. These data and all the cosmids described are publicly available.

[Cloning of the gene for extracellular Bacillus circulans RNAase]

The gene for extracellular low molecular weight ribonuclease of Bacillus circulans BCF 247 was cloned. The strain was isolated from permafrost deposits of the Kolyma lowland. The gene for the ribonuclease from Bacillus intermedius (binase) was used as a specific probe. The cloning succeeded only in the E. coli strain producing the inhibitor of ribonuclease form Bacillus amyloliquefaciens. Selected clones secreted the active ribonuclease into the growth media. Deletion derivatives of the parental recombinant plasmid were constructed. The smallest DNA fragment which enclosed a functional ribonuclease gene in E. coli was determined to be 0.6 kb in length.

[Cloning the asd and lysC genes from Cornyebacterium glutamicum]

Plasmids carrying an asd gene from a mutant. S-(2-aminoaethyl)-L-cysteine resistant strain of Corynebacterium glutamicum were selected from a clonoteque constructed on a plasmid cloning vector pSL5 by complementation of asd mutation in Escherichia coli. Evidence has been obtained that the cloned chromosomal DNA fragment contains also a complete sequence for feed-back-resistant aspartokinase lysC gene.

[Diagnostic value of determining neutral alpha-glucosidase and N-acetyl-beta-D-hexosaminidase activity in the urine in kidney pathology]

As shown in studies of 123 patients with various nephropathies, activities of alpha-glucosidase and N-acetyl-beta-D-hexosaminidase in urine of the patients correlated with severity and stages of these diseases; at the same time, simultaneous estimation of both enzymatic activities in urine was shown to be more informative in diagnostic of kidney impairments. Low values of correlation coefficient (r = 0.35 +/- 0.09) between daily excretion of protein and the activity of neutral alpha-glucosidase in urine showed that the enzyme activity did not depend on proteinuria and was independent test for kidney impairment. Estimation of alpha-glucosidase activity could be used for control of the therapy; the enzymatic activity in urine correlated distinctly with the clinico-laboratory patterns of the patients studied.

[Neutral alpha glucosidase in human urine as a marker of kidney impairment]

Distinct correlation was found between the activity of neutral alpha-glucosidase in urine and the degree of kidney impairment in 76 patients and in 15 healthy persons. In the patients with non-impaired kidney functions the activity of the enzyme in urine varied within the normal limits (from 12 to 39 microM/hr/mmole of creatinine; normal value being 14.6-15.9 microM), in the patients with moderately expressed disfunction of kidney--from 40 to 79 microM/hr/mmole of creatinine. The enzymatic activity, exceeding 80 microM/hr/mmole of creatinine (up to 227 mM), was observed in cases of severe impairment of the kidney functions. High activity of alpha-glucosidase, correlating with the severity of kidney impairment was found in urine of patients with pyelonephritis albeit the content of protein was quite normal. Interrelationship between the activity of alpha-glucosidase in urine and the state of kidney functions enables to conclude that the enzymatic activity depends on the degree of kidney impairment under various pathological conditions and that estimation of the enzyme activity in urine may be important for diagnosis of kidney diseases as well as for the control of treatment efficiency.