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To improve the reliability of electrical machines and equipment, it is necessary to change over to operating them based on their actual condition. This article examines the evaluation of the insulation of the windings of an electric drive and describes a method of determining the thermophysical characteristics of the insulation.

Some aspects of modeling of overtravel that is observed in rotor-type electric machine units are examined. Methods are proposed for determining the physical and engineering parameters of those units. The maximum effect from the results of the work could be obtained by using them to supplement the traditional methods of using products under actual conditions.

Postmortem brain tissue was used to measure expression of serotonin transporter mRNA in the left frontal and left temporal cortex from schizophrenics (n = 24) and from normal control individuals with no history of psychiatric illness (n = 10). There was an approximately four-fold increase of serotonin transporter mRNA in Brodmann's area 9 and a two-fold decrease in Brodmann's areas 21 and 22. The changes in serotonin transporter mRNA were more prominent in schizophrenics who had received neuroleptic drugs within 1 week prior to death than in schizophrenics who were neuroleptic-free for more than 2 weeks prior to death, suggesting that the changes may be related to neuroleptic treatment. There was no correlation between serotonin transporter mRNA levels and the sex or age of schizophrenic and control cases or the postmortem delay intervals. These results support the hypothesis that region-specific changes in serotonin transporter expression occur in brains of some schizophrenics. Future studies are necessary to determine whether the changes in serotonin transporter expression are drug-related or are associated with the illness itself.

Cells from transgenic mice expressing a human mini-gene for collagen I were used as markers to follow the fate of mesenchymal precursor cells from marrow that were partially enriched by adherence to plastic, expanded in culture, and then injected into irradiated mice. Sensitive PCR assays for the marker collagen I gene indicated that few of the donor cells were present in the recipient mice after 1 week, but 1-5 months later, the donor cells accounted for 1.5-12% of the cells in bone, cartilage, and lung in addition to marrow and spleen. A PCR in situ assay on lung indicated that the donor cells diffusely populated the parenchyma, and reverse transcription-PCR assays indicated that the marker collagen I gene was expressed in a tissue-specific manner. The results, therefore, demonstrated that mesenchymal precursor cells from marrow that are expanded in culture can serve as long-lasting precursors for mesenchymal cells in bone, cartilage, and lung. They suggest that cells may be particularly attractive targets for gene therapy ex vivo.

Phenotype variability and incomplete penetrance are frequently observed in human monogenic diseases such as osteogenesis imperfecta. Here an inbred strain of transgenic mice expressing an internally deleted gene for the pro alpha 1(I) chain of type I procollagen (COL1A1) was bred to wild type mice of the same strain so that the inheritance of a fracture phenotype could be examined in a homogeneous genetic background. To minimize the effects of environmental factors, the phenotype was evaluated in embryos that were removed from impregnated females 1 d before term. Examination of stained skeletons from 51 transgenic embryos from 11 separate litters demonstrated that approximately 22% had a severe phenotype with extensive fractures of both long bones and ribs, approximately 51% had a mild phenotype with fractures of ribs only, and approximately 27% had no fractures. The ratio of steady-state levels of the mRNA from the transgene to the level of mRNA from the endogenous gene was the same in all transgenic embryos. The results demonstrated that the phenotypic variability and incomplete penetrance were not explained by variations in genetic background or levels in gene expression. Instead, they suggested that phenotypic variation is an inherent feature of expression of a mutated collagen gene.

We have previously reported that the expression of the ColCAT3.6 transgene containing 3.5 kilobases (kb) of alpha 1(I) collagen (COL1A1) promoter sequence fused to the chloramphenicol acetyltransferase (CAT) reporter gene paralleled the expression of the endogenous gene in several connective tissues. We report here that the activity of the reporter gene in aorta from 7-day-old transgenic mice is 10-64-fold lower than in tendon or bone, whereas the endogenous gene is highly expressed in all three tissues. In contrast, the COL1A1 minigene containing 2.3 kb of upstream sequence, the first five exon/intron units, the last six exon/intron units, and 2 kb of 3'-flanking sequence showed high CAT activity in aorta. These results suggest that cis sequences found in ColCAT3.6 mediate high levels of COL1A1 expression in bone and tendon, but not in vascular smooth muscle cells (VSMC), whereas sequences located within the minigene, but not found in ColCAT3.6, mediate VSMC-specific expression. Analysis of promoter activity in cultured cells derived from transgenic tissues further suggests the presence of VSMC-specific regulatory domains. Transient transfection studies, however, failed to shows differential regulation. These differences stress the importance of not relying exclusively on transient transfection data when mapping tissue-specific regulatory domains.

Major depressive disorder is one of the most common and devastating psychiatric disorders. To identify candidate mechanisms for major depressive disorder, we compared gene expression in the temporal cortex from 12 patients with major depressive disorder and 14 matched controls using Affymetrix HgU95A microarrays. Significant expression changes were revealed in families of genes involved in neurodevelopment, signal transduction and cell communication. Among these, the expression of 17 genes related to oligodendrocyte function was significantly (P0.05, fold change1.4) decreased in patients with major depressive disorder. Eight of these 17 genes encode structural components of myelin (CNP, MAG, MAL, MOG, MOBP, PMP22, PLLP, PLP1). Five other genes encode enzymes involved in the synthesis of myelin constituents (ASPA, UGT8), or are essential in regulation of myelin formation (ENPP2, EDG2, TF, KLK6). One gene, that is, SOX10, encodes a transcription factor regulating other myelination-related genes. OLIG2 is a transcription factor present exclusively in oligodendrocytes and oligodendrocyte precursors. Another gene, ERBB3, is involved in oligodendrocyte differentiation. In addition to myelination-related genes, there were significant changes in multiple genes involved in axonal growth/synaptic function. These findings suggest that major depressive disorder may be associated with changes in cell communication and signal transduction mechanisms that contribute to abnormalities in oligodendroglia and synaptic function. Taken together with other studies, these findings indicate that major depressive disorder may share common oligodendroglial abnormalities with schizophrenia and bipolar disorder.

Alterations in the 5-HT2A receptor gene expression in the prefrontal cortex have been suggested to play a role in the pathophysiology and pharmacotherapy of schizophrenia. This study measured mRNA encoding 5-HT2A receptor in the left superior frontal gyrus from chronic elderly schizophrenics (n = 21) with varying neuroleptic-free intervals before death (72 hr to more than 5 years), and normal drug-free elderly controls (n = 14). Levels of 5-HT2A mRNA in schizophrenics correlated significantly and inversely with neuroleptic-free interval before death (r = -0.77; P0.0001). In schizophrenics who had been receiving neuroleptic until time of death, levels of 5-HT2A mRNA were similar to controls or greater. In schizophrenics who had been free of neuroleptic for more than six months levels of 5-HT2A mRNA were significantly lower than in controls. These results confirm previous findings of decreased expression of the 5-HT2A receptor gene in the frontal cortex of some schizophrenics and suggest that regulation of this gene may be involved in the therapeutic actions of typical neuroleptics.

Synaptic abnormalities have been implicated in schizophrenia. In order to investigate synaptic pathology in schizophrenia, we examined levels of mRNAs encoding synaptophysin, synapsin 1A and synapsin 1B in the left temporal cortex from schizophrenics (n = 24) and from normal control individuals with no history of psychiatric illness (n = 10). Levels of synaptic mRNAs in the left superior temporal and left middle temporal gyrus declined significantly with age in schizophrenics, but not in controls. Dividing the diagnostic groups according to age (below and above 75 years), the data revealed that in "young" schizophrenics (age75 years) levels of the three synaptic mRNAs in the left superior and left middle temporal gyri were approximately two times higher than in the age-matched controls. In the "old" schizophrenics (age75 years) the levels of synaptic mRNAs in temporal cortex did not differ from age-matched controls. These findings further support the hypothesis that developmental synaptic abnormalities may be involved in the pathophysiology of schizophrenia.

Inconsistent data have been reported on the size of the promoter that is necessary for high levels of tissue-specific expression of the COL1A1 gene for type I procollagen. Some of the inconsistencies may be traced to the use of reporter gene constructs. Therefore, we prepared transgenic mice with modifications of the intact gene engineered so that the level of expression of the transgene could be assayed both as mRNA and protein that were similar to the products from the endogenous COL1A1 gene. The results with a mini-COL1A1 gene lacking 41 internal exons and introns indicated that the first intron and 90% of the 3'-untranslated region were not essential for tissue-specific expression. In a hybrid COL1A1/COL2A1 construct, a 1.9-kilobase 5'-fragment from the COL1A1 gene that contained only 476 of the promoter was linked to a promoterless 29.5-kilobase fragment of the human COL2A1 gene for type II procollagen. The hybrid COL1A1/COL2A1 construct was expressed as both mRNA and protein in tissues that normally synthesize type I procollagen but not type II procollagen. Apparently, 476 base pairs of the promoter are sufficient to drive tissue-specific expression of the COL1A1 gene and totally inappropriate expression of the COL2A1 gene.

We have previously reported that the expression of the ColCAT3.6 transgene containing 3.5 kilobases (kb) of alpha 1(I) collagen (COL1A1) promoter sequence fused to the chloramphenicol acetyltransferase (CAT) reporter gene paralleled the expression of the endogenous gene in several connective tissues. We report here that the activity of the reporter gene in aorta from 7-day-old transgenic mice is 10-64-fold lower than in tendon or bone, whereas the endogenous gene is highly expressed in all three tissues. In contrast, the COL1A1 minigene containing 2.3 kb of upstream sequence, the first five exon/intron units, the last six exon/intron units, and 2 kb of 3'-flanking sequence showed high CAT activity in aorta. These results suggest that cis sequences found in ColCAT3.6 mediate high levels of COL1A1 expression in bone and tendon, but not in vascular smooth muscle cells (VSMC), whereas sequences located within the minigene, but not found in ColCAT3.6, mediate VSMC-specific expression. Analysis of promoter activity in cultured cells derived from transgenic tissues further suggests the presence of VSMC-specific regulatory domains. Transient transfection studies, however, failed to shows differential regulation. These differences stress the importance of not relying exclusively on transient transfection data when mapping tissue-specific regulatory domains.

Collagens were analyzed in skin and rib cartilage of 9 patients with Ehlers-Danlos syndrome of the II type. Electrophoresis and CNBr-peptide mapping showed that extended inserts and deletions as well as rough impairments of post-translation processing were not detected in collagens of the I, II and III types from these patients. In the patients with Ehlers-Danlos syndrome of the II type distinct increase was observed both in the total ratio of collagens III/I (P = 0.95) and in the ratio of intact collagens III/I free of cross-links. A decrease in content of dimers beta 11 and beta 12 was found in two patients. The data obtained suggest that the Ehlers-Danlos syndrome of the II type involved deteriorations in the structure of collagens I responsible for decrease in stability and sometimes for impairments in cross-link formation. Increase in content of collagen II fraction, predisposed to proteolytic hydrolysis of terminal sites, as well as elevated sensitivity of collagen II to pepsin hydrolysis were found in collagens of rib cartilage from patients with the syndrome and with funnel chest deformation. This suggests the lowered stability of collagen II from rib cartilage in funnel chest deformation.

Structural analysis of hyaline cartilage extracellular matrix components from the ribs and knee joint of a stillborn female with type II achondrogenesis was carried out. The absence of type II collagen, a decrease in the amount of proteoglycans (PG), and structural changes in PG, namely, increased electrophoretic mobility of PG, lower relative content of chondroitin 4-sulfate (Ch4-S), lower molecular weight and decreased total chondroitin sulfate (ChS) sulfation, were detected. Increased amounts of type I and type III collagens, atypical for hyaline cartilage, were revealed. Among the link proteins (LPs), a large protein with a mol. wt. of 48 kDa was predominant. Molecular and cellular mechanisms of the pathogenesis of achondrogenesis ("chondrogenesis imperfecta") are discussed. The data obtained suggest that the primary defect in type II achondrogenesis involves ChS or type II collagen synthesis.

A method of testing glass-reinforced plastic shells under external hydrostatic pressure is described together with a procedure for determining the elastic properties of the material of which the shell is composed. Test data on the strength and stability of shells subjected to external hydrostatic pressure are presented.

Peptide mapping was used for comparative analysis of nonstructural proteins (NS1) of 21 strains of human and animal influenza A viruses. At least 4 groups of NS1 proteins could be distinguished by the analysis of the peptide maps; we designated these groups as 0, 1, 2, and 3. Group O includes NS1 proteins of human influenza virus serotype HON1, group 1 - NS1 proteins of viruses of serotypes H1N1 and H2N2, group 2 - NS1 proteins of viruses of serotype H3N2. NS1 proteins of avian influenza viruses A/duck Czechoslovakia/63, A/turkey Massachusetts/65, A/petrel Australia/1/71, A/duck Ukraine/63, and A/turkey Ontario/68 have been included into group 3.

The method of oligopeptide mapping has shown the presence of similar oligopeptides in nucleocapsid proteins of various influenza viruses, and at the same time diverse oligopeptides in different viruses. This indicates shifts in the sequences of aminoacid residues in various influenza viruses. Various oligopeptide composition of nucleoprotein is marked not only in the viruses with shift hemagglutinin differences (H1 and H3), but also in the drift-variants of viruses (H0-H1).

Influence of various procedures for detection of collagen chains after electrophoresis in polyacrylamide gel on efficiency of their subsequent electroelution from the gel slices into gel of the second direction was studied. Staining of the gels with Coumassy R-250 under mild conditions or radioautography of the gels dried after electrophoresis decreased only slightly the electroelution efficiency as compared with the untreated gels. This observation suggests that direct procedures, which simplified distinctly the experiments, might be used for detection of the polypeptides in initial gel when peptide mapping was carried out using degradation of collagens by means of cyanogen bromide immediately in the gel slices. The procedures were developed, which enabled to perform mapping of collagen individual chains both labelled with 14C-amino acids and unlabelled fractions after their electrophoresis in polyacrylamide gel and the direct detection of polypeptides.

Oligopeptide maps of M proteins of "wild" fowl plague virus (FPV) and a temperature-sensitive mutant of FPV were compared with respect of gene. In maps of M proteins labeled with 14C-chlorella hydrolysate and 35S-methionine the mutant virus was found to lack one of oligopeptides present in maps of M proteins of the "wild" virus. The electrophoretic mobility of M proteins of ts 303 and FPV in 25% polyacrylamide gel was similar.

A comparative study of influenza A virus NP proteins was carried out using peptide mapping. Thirty-five strains of all main serotypes of human and animal viruses were tested. The greatest diversity was found in NP proteins of human influenza viruses belonging to different serotypes, while within serotypes the variability is less pronounced. Four main groups of NP proteins were distinguished and designated NP0, NP1, NP2, and NP3. The NP0 group includes proteins of viruses of HON1 serotype, NP proteins of all avian viruses with the exception of A/shearwater/Australia/1/71 (Hav6Nav5), NP proteins of A/horse/Prague/56 (Heq1Neq1), A/swine/Iowa/1/30 (Hsw1N1), and A/whale/Pacific/76 (HONav2). The NP1 group comprises NP proteins of viruses of HIN1 serotype (with the exception of A/California/78), A/Singapore/57 (H2N2) and NP protein of A/New Jersey/76 (Hsw1N2) virus. The NP2 group includes NP proteins of H3N2 virus serotype and NP protein of A/California/78 (H1N1) virus. NP proteins of A/horse/Miami/63 (Heq2Neq2) and A/shearwater/Australia/1/71 viruses comprise NP3 group.

Tryptic mapping of radioactive methionine-labeled NP proteins of 15 species of human influenzae A viruses and 11 animal viruses was performed. On the basis of similarities and differences of peptide maps, NP proteins were divided into 4 groups designated A, B, C, and D. Group A included viruses A/WS/33 and A/PR/8/34; Group B viruses H1N1 (apart from those isolated after 1977 and WSN virus), H2N2, H3N2, and 8 species of animal influenza viruses, Group C 4 species of H1N1 viruses isolated in 1977-1979 (A/USSR/90/77, A/USSR/086/79, A/USSR/093/79, A/Brazil/79); Group D three species of animal influenza viruses (A/swine/Iowa/30, A/horse/Praha/56, A/duck/England/56).

Study of the effects of pepsin treatment on soluble collagens type I of the skin and collagens type II of the costal cartilage of healthy subjects revealed the presence of two classes of molecules differing in the stability of their three-helical structure. In collagen molecules possessing a low stability (their number may amount to 20-30%) within the temperature range of 4-30 degrees C pepsin causes a split-off of N-terminal sites with the formation of short chains, i.e., alpha 1(I), alpha 2(II), and alpha 1(II), whereas at higher temperatures (33 degrees C for collagens type I and 37 degrees C for collagens type II) a complete degradation of these molecules takes place. It was found that collagens types I and II molecules contain a high number of three-helical sites with a high susceptibility to pepsin. The putative functional role of structural heterogeneity of collagen molecules is discussed.

The electrophoretical analysis and CNBr-peptide mapping of the collagens, isolated from the costal cartilage of 30 patients with non-classified and syndromal forms of pex excavatum (funnel chest) (27 patients) and pex carinatum (3 patients) was carried out. In case of one patient with the nonclassified form of funnel chest the electrophoretical mobility of CB 9.7-peptide was found to be decreased. The electrophoretical mobilities of other peptides are not markedly changed. The data obtained allow one to suggest the mutation causing the defect in the region about 160 amino acid residues distant from the C-end of alpha 1 (II) chain of type II collagen of the patient.

Oligopeptide mapping showed the viruses H1N1 and H3N2 isolated from animals, unlike the majority of animal viruses with "animal" subtypes of the surface antigens, to have NP proteins typical of human H1N1 and H3N2 viruses which confirms their origin from human viruses.

Comparative studies of nonstructural (NS) protein, nucleoprotein protein (NP) and membrane protein (M) of some influenza virus strains were performed by peptide mapping. The greatest differences were found in peptide maps of NS and NP proteins of influenza viruses whereas tryptic 35S-methionine maps of membrane proteins were much less variable. No correlation between the oligopeptide composition of NP, M, and NS proteins and the natural host range of the influenza A viruses under study was found.

The simple technique for isolation of high-molecular eucaryotic DNA has been proposed. It includes cell or nuclei lysates by sodium dodecylsulfate in the presence of pronase, proteins precipitation by potassium acetate, DNA precipitation by ethanol. The DNA isolated by this technique is easily cleaved by restriction endonucleases and can be used for analysis of the unique genes by blot-hybridization. The yield of DNA is similar or somewhat higher than that in case of using the standard methods including phenol extraction or phenol-chloroform extraction.

Oligopeptide mapping of 35S-methionine labeled non-structural (NS1) proteins of 23 influenza. A virus strains showed the presence of both common and variable oligopeptides. Analysis of the oligopeptide maps revealed at least four groups of NS1 proteins. The first group includes NS1 proteins of several human H1N1 influenza viruses (that were designated as H0N1 according to the old classification). The second group is composed of NS1 proteins of H1N1 and H2N2 viruses. The third group includes NS1 proteins of H3N2 human influenza viruses. The fourth group is composed of NS1 proteins of five avian influenza viruses and an equine (H3N8) influenza virus. Two animal influenza viruses A/equi/Prague/56 (H7N7) and A/duck/England/56 (H11N6) contain NS1 proteins that belong to the second group.

Oligopeptide mapping and immunological methods were used to study influenza viruses of the evolutionary series Hsw1-H0-H1 isolated from man and animals. Among the animal viruses some possess hemagglutinins similar to those observed in the viruses isolated from man, while some viruses differ from them. These are assumed to be precursors of the viruses of "Spanish" influenza retained in animals. Variability of the nucleoprotein protein in the viruses under study was observed.

Two highly efficient methods of CNBr-peptide mapping of polypeptides divided by polyacrylamide gel electrophoresis are described. The first is elaborated on the basis of peptide mapping of collagen proposed by G. Barsh et al. The following three modifications diminish wasting the material essential for the method. 1. CNBr treatment takes place in the absence of CNBr solution outside the gel, excluding the peptides elution from the gel fragments in the process of mapping. 2. After CNBr treatment the solution of CNBr is substituted by the samples buffer before electrophoresis by means of drying and subsequent addition of minimal volumes of the buffer. The latter procedures substitute the gel washing out by the buffer solution. 3. The step of washing the gel fragments by the 70% strong solution of formic acid before CNBr treatment is excluded. The second method of CNBr-peptide mapping is notable for extracting peptides from the gel fragments in the process of CNBr-treatment and permits obtaining of the high quality peptide electrophoregrams.

Three classes of NP-proteins were detected by 7% polyacrylamide gel electrophoresis of virion proteins of influenza A various strains. Peptide maps of these proteins vary. The pattern of the discrepancies indicates the presence of two types of influenza A virus NP-protein. Incubation during 30 h at 37 degrees C of the preparations of intact viral particles and particles destroyed by nonion detergent NP-40 does not result in changes of the NP, NP2 and NP3 proteins ratio, that is an evidence of their intracellular origin.

Variants of influenza A virus: A/PR8/34 Pm-, nonpathogenic for mice and A/PR8/34 Pm+, pathogenic for mice, obtained after 5 passages in mice, were studied. Both variants showed close similarities in the antigenic specificity, high reproductive activity at optimal temperature and reduced activity at low and high temperatures, similar plaque-producing activity in chick fibroblast cell cultures. Differences in their polypeptide composition were found. The A/PR8/34 Pm+ variant had no HAO and a lower molecular weight of HA1. In the mapping of HA1 and NP proteins, differences in the oligopeptide compositions were observed.

A comparative study of protein of nucleoproteins (NP-protein) of influenza A viruses by peptide mapping shows its variability to be small within one drifting series and quite marked in strains belonging to different sero-types. In oligopeptide maps of NP-proteins of viruses of the Hong Kong (H3N2) series there is a typical group of spots differing them from oligopeptide maps of NP-proteins of viruses of other serotypes, particularly of the preceeding serotype H2N2 and the viruses related by hemagglutinin: A/duck/Ukraine/63 (Hav7Neq2) and A/horse/Miami/63 (Heq2Neq2). NP-proteins of the old A/swine/Iowa/30 and new A/New Jersey/76 strains of swine influenza viruses belonging to the same serotype Hsw1N1 differ from each other but are similar to NP-proteins of viruses of H0N1 and H1N1 serotypes, respectively.

The electrophoretic mobilities of the collagen and procollagen type I and III chains synthesized by the fibroblasts isolated from patients with type I Ehlers-Danlos syndrome as well as a set of peptides obtained by splitting of pro alpha 1(I) and pro alpha 2(I) type I procollagens by cyanbromide are not different from the normal ones. The fact demonstrates the absence of long insertions or deletions, or the sufficient defects in intracellular chain modifications. The changes were also nor registered for the ratio of type I and III collagens from the digested by pepsin preparations of protein accumulating in the culture media of the cultured skin fibroblasts from patients. The studied strains of cultured fibroblasts from patients suffering the Ehlers-Danlos syndrome have the trend to increased accumulation of partially processed chains of proc alpha 1(I) and proc alpha 2(I) type I procollagen and to the increased ratio of pro alpha 1(I) to pro alpha 2(I).

Summary Oligopeptide mapping of nucleoproteins (NP proteins) of 54 strains of influenza A virus showed the presence of both common and individual oligopeptides. Using the distribution of variable oligopeptides as the criterion, NP proteins were subdivided into four groups (NP0, NP1, NP2 and NP3). The NP0 group is composed of H0N1 influenza viruses and the majority of animal influenza viruses. The NP1 group contains H1N1 (except A/California/78) and H2N2 influenza viruses isolated from man as well as H1N1 influenza viruses recently isolated from animals. A/New Jersey/76 (Hsw1N1) influenza virus also belongs to the NP1 group. The NP2 group consists of H3N2 influenza viruses isolated from man and animals. A/California/78 (H1N1) influenza virus also falls into the NP2 group. The NP3 group contains NP proteins of four animal influenza viruses with the antigenic formulas Hsw1N2, Hsw1Nav2, Hav6Nav5 and Heq2Neq2.

Investigation of influenza viruses isolated from man and animals and having hemagglutinin of the H3 subtype according to the new nomenclature (H3, Heq2 and Hav7 according to the old nomenclature) by serological methods (including the use of monoclonal antibody) and oligopeptide mapping showed that many animal isolates reflected an antigenic drift of the Hong Kong virus series which has been going on since 1968 until now. At the same time a number of isolates represent precursors of viruses of the Hong Kong series circulating among the human population. It is suggested that this is not the first time that viruses of the Hong Kong series have been introduced into the human population.

Skin and rib cartilage collagens were studied in patient 1.I.K. with isolated form of pigeon chest as well as in a group of children without any impairments of connective tissue. Distinct decrease in stability of collagen I, an increase in the ration of alpha 1 (I)/alpha 2(I) chains and impairment in formation of beta 12 dimers were detected in the patient with pigeon chest. In the patient skin total ratio between collagens I and III, calculated from a content of BrCN-peptides, was similar to normal level, whereas the proportion was markedly increased between intact molecules of collagens III and I free of cross-links, which was calculated from the ratio of alpha 1(III)/alpha 2(I) chains. Presence of cross-links between alpha 1 (III) and alpha 2 (I) chains as well as between alpha 1 (III) and alpha 2 (I) chains was detected after peptide mapping of polypeptides arranged in the region of beta 11 and beta 12 dimers. All the collagen I preparation, extracted from skin of the patient 1.I.K., contained molecules with unstabilized N-terminal sites. These results suggest that mutation occurred in the N-terminal region of alpha 1(I) chain. Analysis of collagen from the patient 1.I.K. rib cartilage demonstrated a slight decrease in total stability of collagen II as well as elevated concentration of collagen II molecules containing unstabilized N-terminals. Mechanisms responsible for formation of cross-links between polypeptide chains of collagens I and III detected in human skin are discussed.