Potential and limits of Raman spectroscopy for carotenoid detection in microorganisms: implications for astrobiology

In this paper, it is demonstrated how Raman spectroscopy can be used to detect different carotenoids as possible biomarkers in various groups of microorganisms. The question which arose from previous studies concerns the level of unambiguity of discriminating carotenoids using common Raman microspectrometers. A series of laboratory-grown microorganisms of different taxonomic affiliation was investigated, such as halophilic heterotrophic bacteria, cyanobacteria, the anoxygenic phototrophs, the non-halophilic heterotrophs as well as eukaryotes (Ochrophyta, Rhodophyta and Chlorophyta). The data presented show that Raman spectroscopy is a suitable tool to assess the presence of carotenoids of these organisms in cultures. Comparison is made with the high-performance liquid chromatography approach of analysing pigments in extracts. Direct measurements on cultures provide fast and reliable identification of the pigments. Some of the carotenoids studied are proposed as tracers for halophiles, in contrast with others which can be considered as biomarkers of other genera. The limits of application of Raman spectroscopy are discussed for a few cases where the current Raman spectroscopic approach does not allow discriminating structurally very similar carotenoids. The database reported can be used for applications in geobiology and exobiology for the detection of pigment signals in natural settings.

Production of proteolytic enzymes in mast cells, fibroblasts, vascular smooth muscle and endothelial cells cultivated under normoxic or hypoxic conditions

Matrix metalloproteinases (MMPs) is a family of proteolytic enzymes involved in remodeling of extracellular matrix. Although proteolytic enzymes are produced by many cell types, mast cells seem to be more important than other types in remodeling of pulmonary arteries during hypoxia. Therefore, we tested in vitro production of MMPs and serine proteases in four cell types (mast cells, fibroblasts, vascular smooth muscle cells and endothelial cells) cultivated for 48 h under normoxic or hypoxic (3% O2) conditions. MMP-13 was visualized by immunohistochemistry, MMP-2 and MMP-9 were detected by zymography in cell lysates. Enzymatic activities (MMPs, tryptase and chymase) were estimated in the cultivation media. Hypoxia had a minimal effect on total MMP activity in the cultivation media of all types of cells, but immunofluorescence revealed higher intensity of MMP-13 in the cells exposed to hypoxia except of fibroblasts. Tryptase activity was three times higher and chymase activity twice higher in mast cells cultivated in hypoxia than in those cultured in normoxia. Among all cell types studied here, mast cells are the most abundant source of proteolytic enzymes under normoxic and hypoxic conditions. Moreover, in these cells hypoxia increases the production of both specific serine proteases tryptase and chymase, which can act as MMPs activators.

Hypercapnia attenuates hypoxic pulmonary hypertension by inhibiting lung radical injury

Chronic lung hypoxia results in hypoxic pulmonary hypertension. Concomitant chronic hypercapnia partly inhibits the effect of hypoxia on pulmonary vasculature. Adult male rats exposed to 3 weeks hypoxia (Fi(02)=0.1) combined with hypercapnia (Fi(C02)=0.04-0.05) had lower pulmonary arterial blood pressure, increased weight of the right heart ventricle, and less pronounced structural remodeling of the peripheral pulmonary arteries compared with rats exposed only to chronic hypoxia (Fi(02)=0.1). According to our hypothesis, hypoxic pulmonary hypertension is triggered by hypoxic injury to the walls of the peripheral pulmonary arteries. Hypercapnia inhibits release of both oxygen radicals and nitric oxide at the beginning of exposure to the hypoxic environment. The plasma concentration of nitrotyrosine, the marker of peroxynitrite activity, is lower in hypoxic rats exposed to hypercapnia than in those exposed to hypoxia alone. Hypercapnia blunts hypoxia-induced collagenolysis in the walls of prealveolar pulmonary arteries. We conclude that hypercapnia inhibits the development of hypoxic pulmonary hypertension by the inhibition of radical injury to the walls of peripheral pulmonary arteries.

Hybridization analysis and mapping of the celesticetin gene cluster revealed genes shared with lincomycin biosynthesis

The first insight into celesticetin biosynthetic gene cluster of S. caelestis is presented. The genomic DNA of producing strain was digested, digoxigenin-labeled and hybridized with a set of probes designed according to S. lincolnensis gene sequences. Genes with high homology to the lincomycin biosynthetic genes coding for the predicted common parts of the pathway were identified in S. caelestis. Then, genomic DNA of S. caelestis treated by a multiple digestion was hybridized with five digoxigenin-labeled probes to construct a rough restriction map. Two consecutive islands formed by the genes with a putative function in biosynthesis of the shared saccharide moiety revealed an organization similar to the lincomycin biosynthetic gene cluster. The celesticetin cluster was mapped and essential information was obtained for subsequent steps, i.e. isolation and sequence analysis of the cluster.

In vitro hypoxia increases production of matrix metalloproteinases and tryptase in isolated rat lung mast cells

Chronic hypoxia results in hypoxic pulmonary hypertension characterized by fibrotization and muscularization of the walls of peripheral pulmonary arteries. This vessel remodeling is accompanied by an increase in the amount of lung mast cells (LMC) and the presence of small collagen cleavage products in the vessel walls. We hypothesize that hypoxia activates LMC, which release matrix metalloproteinases (MMPs) cleaving collagen and starting increased turnover of connective tissue proteins. This study was designed to determine whether in vitro hypoxia stimulates production of MMPs in rat LMC and increases their collagenolytic activity. The LMC were separated on the Percoll gradient and then were divided into two groups and cultivated for 24 h in 21 % O(2) + 5 % CO(2) or in 10 % O(2) + 5 % CO(2). Presence of the rat interstitial tissue collagenase (MMP-13) in LMC was visualized by immunohistological staining and confirmed by Western blot analysis. Total MMPs activity and tryptase activity were measured in both cultivation media and cellular extracts. Exposure to hypoxia in vitro increased the amount of cells positively labeled by anti-MMP-13 antibody as well as activities of all measured enzymes. The results therefore support the concept that LMC are an important source of increased collagenolytic activity in chronic hypoxia.

Changes of extracellular matrix of rat cornea after exposure to hypoxia

The purpose of the study was to check whether hypoxia of corneal tissue increases the collagenolytic activity due to release of reactive oxygen and nitrogen species. Rats were exposed to hypoxia 10% O(2) for 4, 14, and 21 days. The radical tissue injury was measured by the level of nitrotyrosine and changes in the lipoperoxide-related fluorophores. Collagen protein composition was analyzed by slab gel electrophoresis. The activity of gelatinolytic enzymes was studied using the zymography. The vascularization of the corneas was measured. We found no differences in the corneal tissue in the gel electrophoretic profile of collagenous proteins and gelatinolytic activity between normoxic and hypoxic rats. We did not find any sign of radical tissue injury. There were no changes in the vascularization of corneas after exposition to hypoxia. The environmental 10% hypoxia does not induce radical tissue injury and an increase of collagenolytic activity in the rat cornea.

Possible role of matrix metalloproteinases in reconstruction of peripheral pulmonary arteries induced by hypoxia

Exposure to chronic hypoxia results in hypoxic pulmonary hypertension characterized by structural remodeling of peripheral pulmonary vasculature. An important part of this remodeling is an increase of collagen turnover and deposition of newly formed collagen fibrils in the vascular walls. The activity of collagenolytic metalloproteinases in the lung tissue is notably increased in the first days of exposure to hypoxia. The increased collagenolytic activity results in the appearance of collagen cleavages, which may be implied in the triggering of mesenchymal proliferation in peripheral pulmonary arteries. We hypothesize that radical injury to pulmonary vascular walls is involved in collagenolytic metalloproteinase activation.

Hyperoxia and recovery from hypoxia alter collagen in peripheral pulmonary arteries similarly

Chronic hypoxia causes pulmonary hypertension, the mechanism of which includes altered collagen metabolism in the pulmonary vascular wall. This chronic hypoxic pulmonary hypertension is gradually reversible upon reoxygenation. The return to air after the adjustment to chronic hypoxia resembles in some aspects a hyperoxic stimulus and we hypothesize that the changes of extracellular matrix proteins in peripheral pulmonary arteries may be similar. Therefore, we studied the exposure to moderate chronic hyperoxia (FiO2 = 0.35, 3 weeks) in rats and compared its effects on the rat pulmonary vasculature to the effects of recovery (3 weeks) from chronic hypoxia (FiO2 = 0.1, 3 weeks). Chronically hypoxic rats had pulmonary hypertension (Pap = 26 +/- 3 mm Hg, controls 16 +/- 1 mm Hg) and right ventricular hypertrophy. Pulmonary arterial blood pressure and right ventricle weight normalized after 3 weeks of recovery in air (Pap = 19 +/- 1 mm Hg). The rats exposed to moderate chronic hyperoxia also did not have pulmonary hypertension (Pap = 18 +/- 1 mm Hg, controls 17 +/- 1 mm Hg). Collagenous proteins isolated from the peripheral pulmonary arteries (100-300 microm) were studied using polyacrylamide gel electrophoresis. A dominant low molecular weight peptide (approx. 76 kD) was found in hypoxic rats. The proportion of this peptide decreases significantly in the course of recovery in air. In addition, another larger peptide doublet was found in rats recovering from chronic hypoxia. It was localized in polyacrylamide gels close to the zone of alpha2 chain of collagen type I. It was bound to anticollagen type I antibodies. An identically localized peptide was found in rats exposed to moderate chronic hyperoxia. The apparent molecular weight of this collagen fraction suggests that it is a product of collagen type I cleavage by a rodent-type interstitial collagenase (MMP-13). We conclude that chronic moderate hyperoxia and recovery from chronic hypoxia have a similar effect on collagenous proteins of the peripheral pulmonary arterial wall.

Major proteins related to chlortetracycline biosynthesis in a Streptomyces aureofaciens production strain studied by quantitative proteomics

Changes in synthesis and abundance of proteins associated with chlortetracycline (CTC) production in Streptomyces aureofaciens were investigated by two-dimensional polyacrylamide gel electrophoresis of proteins pulse-labelled in vivo with L-[35S]methionine. Eleven individual protein spots were selected as being related to formation of the antibiotic. Expression of these prominent proteins was not observed in the non-producing mutant; moreover, they were overexpressed in cultures grown in the presence of benzyl thiocyanate, a specific stimulator of CTC biosynthesis used in industrial fermentations. The expression kinetics of the selected proteins was assessed using the technique of computer-assisted image analysis with the EQIAS software and the elongation factor Tu as an internal standard. Interestingly, the kinetic profiles were generally not identical. including those of anhydrotetracycline monooxygenase and the 13-kDa subunit of tetracycline dehydrogenase, two enzymes involved, in the terminal sequential steps of the CTC biosynthetic pathway. The presence of more forms of these enzymes with different charge characteristics was observed. The data presented demonstrated how dramatically the industrial microorganism can change its protein repertoire during the production phase; at least five proteins were nearly comparable in level to the most prominent proteins, exemplified by elongation factor Tu.

Putative lmbI and lmbH genes form a single lmbIH ORF in Streptomyces lincolnensis type strain ATCC 25466

The lincomycin-production gene cluster of the industrial overproduction strain Streptomyces lincolnensis 78-11 has been sequenced (Peschke et al. 1995) and twenty-seven putative open reading frames with biosynthetic or regulatory functions (lmb genes) identified. Two distinct hypothetical genes, lmbI and lmbH, were found downstream of the lmbJ gene, coding for LmbJ protein, which is believed to participate in the last lincomycin biosynthetic step, i.e. conversion of N-demethyllincomycin (NDL) to lincomycin. In the present study, we demonstrate the presence of a single larger open reading frame, called lmbIH, in the lincomycin low-production type strain Streptomyces lincolnensis ATCC 25466, instead of two smaller lmbI and lmbH genes. The product, LmbIH, is a protein of an unknown function and is homologous with the T1dD protein family. Escherichia coli T1dD protein was previously shown to be involved in the control of DNA gyrase by LetD protein. Moreover, our experiments indicate co-regulation of lmbJ and lmbIH expression. This translation coupling probably reflects an eight nucleotide overlap between the lmbJ and lmbIH genes, as well as the lack of a Shine-Dalgarno sequence upstream of the lmbIH gene.

A possible role of the oxidant tissue injury in the development of hypoxic pulmonary hypertension

Chronic sojourn in hypoxic environment results in the structural remodeling of peripheral pulmonary arteries and pulmonary hypertension. We hypothesize that the pathogenesis of changes in pulmonary vascular structure is related to the increase of radical production induced by lung tissue hypoxia. Hypoxia primes alveolar macrophages to produce more hydrogen peroxide. Furthermore, the increased release of oxygen radicals by other hypoxic lung cells cannot be excluded. Several recent reports demonstrate the oxidant damage of lungs exposed to chronic hypoxia. The production of nitric oxide is high in animals with hypoxic pulmonary hypertension and the serum concentration of nitrotyrosine (radical product of nitric oxide and superoxide interaction) is also increased in chronically hypoxic rats. Antioxidants were shown to be effective in the prevention of hypoxia induced pulmonary hypertension. We suppose that the mechanism by which the radicals stimulate of the vascular remodeling is due to their effect on the metabolism of vascular wall matrix proteins. Non-enzymatic protein alterations and/or activation of collagenolytic matrix metalloproteinases may also participate. The presence of low-molecular weight cleavage products of matrix proteins stimulates the mesenchymal proliferation in the wall of distal pulmonary arteries. Thickened and less compliant peripheral pulmonary vasculature is then more resistant to the blood flow and the hypoxic pulmonary hypertension is developed.

In situ fluorescence visualization of bromouridine incorporated into newly transcribed nucleolar RNA

Bromouridine-triphosphate is commonly used for in situ immunocytochemical labeling of newly synthesized RNA in living cells. While extranucleolar transcripts do not require special conditions for visualization, special treatment prior to fixation (e.g. incubation with alpha-amanitine) is necessary for immunofluorescence detection of bromouridine-labeled nucleolar RNA in previous studies. We show in the present investigation that bromouridine-triphosphate is efficiently used by both extranucleolar and nucleolar RNA polymerases in living cultured cells. The failure to detect incorporated bromouridine within nucleoli is entirely due to improper treatment of cells after bromouridine incorporation. When methanol/acetone fixation is used, fluorescence signals within nucleoli can be routinely found.

[Mechanisms of remodeling of pulmonary blood vessels in chronic hypoxia]

Chronic lung hypoxia results in the hypoxic pulmonary hypertension, which is caused by the remodeling of peripheral pulmonary blood vessels. Vascular smooth muscle cells proliferate into the prealveolar arteries, the turnover and deposition of connective tissue proteins is increased. We observed an enhanced collagenolytic activity in the extracts from isolated peripheral lung arteries of hypoxic rats. SDS electrophoresis of collagenous proteins extracted from these vessels showed presence of the low molecular weight cleavages of collagen type I. We hypothesize that the activation of collagenolytic metalloproteinases is related to the release of reactive oxygen species, NO and products of their interaction (peroxynitrite). Collagen cleavages may stimulate mesenchymal proliferation in the vascular wall.

Binding of lead to collagen type I and V and alpha2(I) CNBr (3,5) fragment by a modified Hummel-Dreyer method

Binding of lead (as lead acetate) to collagen type I alpha, and alpha2 chains, collagen type V and a large cyanogen bromide fragment of type I collagen [alpha2(I)CB(3,5)] was investigated by the large-zone Hummel-Dreyer method. It was demonstrated that two categories of binding sites exist in the collagen molecule, the number of which correlates rather well with the available aspartic and glutamic acid residues. Similar results were obtained for all collagen chains (fragments) used. The number of sites thus obtained was compared with the cross-striation pattern (reflecting areas where lead is bound) of the SLS form of collagen type I (alpha1 chain); it is suggested that the number of bands seen in the SLS form reflects primarily the number of available aspartic acid residues in the molecule. The association constants obtained are comparable with the low affinity interactions seen e.g., between Cu and bovine serum albumin.

Accumulation of lead in tissues after its administration in drinking water to laboratory rats

Lead administered to laboratory rats in drinking water (0.1-0.8%) as lead acetate solution tends to accumulate in collagen-rich tissues such as tendons and the skin. The amount of lead deposited (and also zinc present in the tissue without its supplementation) correlates with the blood supply to the tissue investigated. The highest deposits of lead were observed in placenta and chorionic membranes, though here only about 60% are collagen-bound. No differences in the drinking habits of the animals were observed and also at lower concentrations of lead in the drinking water no dose dependence was revealed. However, at 0.8% of lead in drinking water considerable accumulation of lead was observed in all tissues investigated.

[Treatment of multiple myeloma with high-dose chemotherapy and transplantation of autologous hematopoietic stem cells and subsequent maintenance therapy with interferon alfa-2b or interferon alfa 2b and dexamethasone. Report of the ongoing study of the "4W" Czech Myeloma Group]

We report our results with high-dose chemotherapy in previously untreated multiple myeloma patients (4 courses of VAD chemotherapy, collection of PBSC after priming with cyclophosphamide, 5 g/m2, high-dose chemotherapy with melphalan, 200 mg/m2). Second transplantation was indicated only for patients who did not achieve remission after the first high-dose therapy (paraprotein lower than 25% of the pretreatment value). For the second transplantation melphalan (200 mg/m2) with methylprednisolone (1.5 g for 5 days) were used as conditioning regimen. After high-dose therapy all patients were randomized into two arms of maintenance therapy: interferon alpha-2b or sequential maintenance therapy (interferon alpha-2b for 3 months followed after 4 week pause by 40 mg of dexamethasone days 1-4, 10-13 and 20-23. The administration of interferon alpha was resumed four weeks after the last dexamethasone for next three months. The maintenance therapy continued for 48 months or until the progression. Fifty-five patients were enrolled in the study from January 1996 to August 1997. Thirty-five patients have undergone the first transplantation and 57% of them reached complete remission. There were 10% of non-responders after the first high-dose regimen. The mean time to reach white blood cell count above 1 x 10(9)/L after the application of high dose melphalan and platelets more than 50 x 10(9)/L were 12.2 (range 6-16 days) and 12.4 (range 0-25 days), respectively. Grade 4 mucositis according to SWOG classification requiring total parenteral nutrition was presented in 40% of the patients. The mean number of 1 unit of platelets and 2 units of packed red blood cells transfusions were given within the posttransplant period. Early transplant related mortality was 3%. This paper describes the response and tolerance of each particular step of therapy. The follow-up has been too short to evaluate event-free and overall survivals.

Micropreparation of tissue collagenase fragments of type I collagen in the form of surfactant-peptide complexes and their identification by capillary electrophoresis and partial sequencing

Combination of standard approaches like pepsin digestion and slab gel electrophoresis with capillary separations allows a relatively easy identification of in vivo occurring collagen fragments. Capillary electrophoresis can be done either in 25 mM phosphate buffer (pH 2.5) or in a 25 mM phosphate buffer (pH 4.5) made 0.1% with respect to sodium dodecyl sulfate (SDS). While in the first case peptides move to the cathode in a molecular mass dependent manner, in the second case they move towards anode (also in a molecular mass dependent manner). The profiles obtained by the two approaches resemble mirror images with low molecular mass peptides moving first in the acid background electrolyte while they move last in the presence of SDS. It is proposed that in the capillary electrophoretic separation at pH 2.5 the separation mechanism involves the interaction of the individual peptides with the capillary wall while in the second case (pH 4.5) the leading mechanism of separation involves the interaction of the analytes with the micellar phase. For micellar phase separation the system must be run at reversed polarity. Capillary electrophoretic separation in the pH 2.5 buffer is considerably affected by the presence of SDS in the previous steps of peptide preparation. If the peptides are obtained from SDS slab gel electrophoresis, their movement in the capillary electrophoresis step is about three times faster that the movement of corresponding peptides which have not been complexed with SDS.

Exposure to chronic hypoxia induces qualitative changes of collagen in the walls of peripheral pulmonary arteries

Qualitative changes of vascular wall matrix collagens in chronic hypoxic pulmonary hypertension were studied by gel electrophoresis. Male adult rats (n = 12) were exposed to hypoxia (FiO2 = 0.1, 3 wks). Control rats (n = 13) were kept in air. Samples of peripheral pulmonary arteries (PPA, diam. 100-400 microm), main branches of pulmonary artery, and aorta were dissected. Arterial samples were treated with 4M guanidine-HCl to remove noncollagenous moieties and the collagenous stroma was dissolved by limited pepsin digestion at low pH. Low molecular mass peptides (M. W. approx. 76 and 66 kD) were detected in the gel electrophoretic profile of collagen peptides of PPA of the chronically hypoxic animals and in aorta of both hypoxic and normoxic groups. These peptides were absent in the PPA of normoxic rats. Since the 76 kD peptide bound anticollagen type I antibodies, it appears to be of collagenous nature and it may be the result of collagenolytic activity in PPA isolated from hypoxic lungs. This was confirmed by zymography. We conclude that exposure of rats to chronic hypoxia results in the presence of low molecular mass peptides in the wall matrix of PPA which resemble those found in aorta of normoxic animals. Collagenolytic activity in the walls of peripheral pulmonary arteries may participate in the mechanism of lung vascular remodelling in chronic hypoxia.

Oxidized collagen stimulates proliferation of vascular smooth muscle cells

We hypothesize that the vascular smooth muscle proliferation after lung injury results from oxidative damage to the matrix proteins in the walls of pulmonary blood vessels. The smooth muscle cells (SMC) isolated from rat aorta were cultured on the surface coated with oxidized and nonoxidized (control) collagen of type I. Oxidation of collagen was induced by UV irradiation and characterized by fluorescence tridimensional spectral arrays and by gel electrophoresis. From day 1 to 6 of the experiment, SMC proliferated more rapidly on the oxidized collagen than on the control surface. At high SMC population densities (day 9 of experiment) the difference disappeared. After 10 min of trypsinization the cells growing on oxidized collagen rounded and detached completely from the growth surface. The control cells on nonoxidized collagen detached only after 30 min of trypsinization. We conclude that oxidation of collagen of vascular wall matrix may participate in stimulation of SMC proliferation after oxidant tissue injury.

Quantitation of collagen types I, III and V in tissue slices by capillary electrophoresis after cyanogen bromide solubilization

A method for the determination of the proportions of major fiber-forming collagens (types I, III and V) in soft connective tissue was elaborated. The method is based on the release of insoluble collagen by CNBr with subsequent separation of the arising peptides. For routine application the peptides are separated by capillary electrophoresis (50 mM phosphate pH 2.5, 15 kV, 50 degrees C, 70/60 cm x 70 microns I.D. capillary with UV detection at 200 nm). Quantitation of collagen type I can be done either on the basis of spiking the sample with a peptide mixture obtained from a known amount of collagen type I, or by spiking the sample with an equimolar mixture of the two peptides [alpha 1(I)CB2 and alpha 1(I)CB4] (constituting a fused peak) along with alpha 1(III)CB2 and alpha 1(V)CB1. Compared to the previously published methods the procedure is faster and does not require isolation of marker peptides by tedious chromatographic procedures in a preceding preparatory step. Good results are obtained within a wide range of run buffer concentrations and applied voltages; conversely, intensive cleaning of the capillary after every three runs is recommended with a new capillary after 20-30 runs.

Capillary zone electrophoresis of collagen type I CNBr peptides in acid buffers

Collagen type-I CNBr peptides were separated under acidic conditions by capillary electrophoresis. Separation conditions were: 100 mM phosphate buffer pH 2.5, 50 cm x 50 microns capillary (placed in a cartridge), 8 kV, running time 30-45 min, detection by UV at 200 nm. The peptides were separated strictly by their molecular mass and the overall pattern was well comparable to RP-HPLC separations of these analytes. It is proposed that the separation mechanism may involve hydrophobic sorptions to the capillary wall.

[EEG correlates of therapeutic effects of electroconvulsive therapy]

In a group of 52 patients electroconvulsive treatment by means of a Thymatron apparatus was provided under simultaneous EEG control. In addition to parameters of the EEG curve (type of curve according to intensity of the paroxysmal process, duration of electroconvulsion on EEG, type of termination of paroxysm of EEG) also other variables were investigated in relation to the therapeutic effect. The following were identified as significant predictors for marked clinical improvement: type of EEG curve with more marked paroxysmal activity, shorter cumulative duration of electroconvulsions on EEG before first clinical improvement of the patient and a higher CGI entering score. Other variables proved unimportant, e.g. the patient's age, total number of electroconvulsions, total cumulative duration of electroconvulsions on EEG and type of termination of electroconvulsions on EEG.

[Patient satisfaction with treatment at the Psychiatric Hospital in Brno]

The objective of the research was to assess the satisfaction with treatment among patients of the mental sanatorium by an anonymous enquiry. In the enquiry 301 patients with different diagnoses participated, incl. some who had protective treatment. The investigation was made in open and closed wards. The majority of patients, reported a relatively high general satisfaction with treatment and the care provided by health professionals and a low grade of satisfaction as regards information on the drugs they took, on their health status and with opportunities how to spend their leisure time.

Purification and characterization of a novel valine dehydrogenase from Streptomyces aureofaciens

The first valine dehydrogenase of S. aureofaciens had been described (Vancurová, I., Vancura, A., Volc, J., Neuzil, J., Flieger, M., Basarová, G. and Bĕhal, V. (1988) J. Bacteriol. 170, 5192-5196). In the present work, a second valine dehydrogenase was detected and purified by hydrophobic and fast protein liquid chromatographies. The enzyme has a relative molecular mass (M(r)) of 240,000 and is composed of 6 identical subunits, each of M(r) 41,000. In the presence of NAD, the enzyme catalyzes the reversible deamination of several branched- and straight-chain amino acids. The enzyme activities with L-2-aminobutyrate and deamino-NAD+ are markedly higher than those with L-valine and NAD+, respectively. The enzyme synthesis is significantly induced by L-valine but severely repressed by ammonia. Molecular and catalytic properties of the enzyme distinguish it from the other described valine dehydrogenases. The results directly demonstrate the presence of two valine dehydrogenases in a single Streptomyces species.

Protein profiles of Streptomyces aureofaciens producing tetracyclines: reappraisal of the effect of benzyl thiocyanate

Cell protein profiles of submerged cultures of Streptomyces aureofaciens cultivated in the absence or presence of 12 microM benzyl thiocyanate (BT) were analyzed by one-dimensional SDS polyacrylamide gel electrophoresis. Substantial increase in the intensity of the 13, 35, 37, 60, and 100 kDa protein bands was observed in cultures treated with BT. Similar increase in the 35, 37, and 60 kDa bands was found in a mutant blocked in the last chlortetracycline biosynthesis step. Effect of BT on the solid medium-grown cultures was also observed, with a more intensive substrate mycelium pigmentation and alteration in the spore size and shape as the most characteristic features. Earlier studies of BT effect involving those on the stimulation of chlortetracycline biosynthesis are summarized and a possible signal-transducing mechanism is discussed from the point of view of adaptation of S. aureofaciens to the uncoupling of oxidative phosphorylation.

Effect of the tripeptide glycyl-L-histidyl-L-lysine on the proliferation and synthetic activity of chick embryo chondrocytes

Under certain conditions chondrocytes form lattices with cartilage collagens, which may serve as cartilage implants. It is necessary to find the optimal conditions for culturing chondrocytes. Three different supports are compared: (a) plastic; (b) cartilage collagens; and (c) insoluble skin collagen solubilized under denaturing conditions (ISC-40). The effect of culture medium supplementation with the tripeptide (Gly-His-Lys)2.Cu.2H2O.2NaCl (GHK) on chondrocyte proliferation and synthetic activity is studied, with particular attention paid to collagen types I, II and III. The collagen supports stimulated chondrocyte proliferation, but on the ISC-40 support they started to dedifferentiate rather early. In the primary culture, chondrocytes on all three supports synthesized mainly collagen type II, and only small amounts of types I and III. In the first passage the synthesis of these two collagen types increased, relative to collagen type II, at least on the cartilage collagen support. Supplementation of culture medium with GHK stimulated chondrocyte proliferation in the primary structure mostly on the ISC-40 support. On the other two types of supports the stimulatory effect of GHK was expressed mostly in the first passages. The collagen synthetic rate was increased by GHK on both of the collagen supports; on the cartilage collagen support collagen type II was synthesized predominantly and on the ISC-40 support types I and III were mostly formed. It is suggested that supplementation of culture medium with GHK may be useful in the preparation of cartilage implants.

[Experience with the Thymatron DG apparatus in determining the duration of electroconvulsions]

Electroconvulsive therapy was administered, using a Thymatron apparatus DG in a group of 29 female patients with a total number of 150 convulsions. The apparatus makes it possible to take an EEG reading and to evaluate it automatically. Moreover, the paroxysm were evaluated clinically and visually from EEG tracings. The authors proved a significant disagreement as regards evaluation of the length of electroconvulsions assessed by the three methods of evaluation (clinical, automatic EEG analyzer and visual EEG evaluation). They identified moreover in the group, using the automatic EEG analyzer, 11.7% abortive convulsions, by visual EEG evaluation 10.3%, while according to clinical evaluation the rate was as high as 59.2%. Conversely on clinical evaluation no convulsion appeared to be protracted, while according to EEG this was the case in 9.6% (automatic analyzer) and in 10.3% (visual evaluation). On qualitative discrimination of abortive and protracted convulsions and convulsions with a satisfactory duration the automatic and visual EEG evaluation did not differ significantly, and the function of the automatic analyzer seems satisfactory for this basic evaluation of electroconvulsions.

Evidence for the degradation of type XI collagen by bovine intervertebral disc- and articular cartilage extracts

Bovine intervertebral disc- and articular cartilage extracts contain a metalloproteinase system capable of degrading type XI collagen. The collagen-degrading activity is rather low in unmodified extracts but increases considerably on metalloproteinase activation. The similarity between intervertebral disc and articular cartilage in their patterns of (casein-degrading) metalloproteinases and type XI and type II collagen degradation is believed to suggest a similarity in the events underlying the degradative disorders of articular cartilage and intervertebral disc.

Characteristics of Streptomyces globisporus strain 0234A forming endospores in submerged cultures

Thermosensitive submerged endospores formed by Streptomyces globisporus 0234 and its natural variant A resembled those of thermoresistant actinomycetes not only in their morphology ultrastructure, but also in the content of dipicolinic acid. The production of endospores containing this substance is unusual in Streptomyces while other features of the strain indicate relatedness to other streptomycetes. Chemotaxonomic analysis of variant A revealed the cell wall to be of chemotype I and fatty acid content typical of Streptomyces. Most characteristics of surface cultures of variant A coincided with those of the original strain 0234 and its endosporeless variant B. Both the strain 0234 and its variants A and B produced identical antibiotics and pesticidal compounds.

[Prosthesis of ligament by specially treated collagenous tissue.]

Artificial prostheses of ligaments are associated with many problems. At first they take over the function of the ligament, later however their strength declines. Therefore at present collagen autotransplants are prefered. Prosthesis made from processed seem however promising, after their breakdown they should be replaced by the patient's connective tissue with an orientation of fibres resembling the original ligament. The poor results reported in the literature are probably due to inadequate treatment of these ligaments. The authors mention their own method of treatment of collagen and its use as a prosthesis of ligaments in experiments on dogs. These ligaments were investigated by histological methods after an interval of 3 and 6 months following operation. The reported results are promising. Histological examination revealed incorporation of connective tissue into the artificial collagen and the connective tissue fibres were oriented parallel with the implanted ligament. Further investigation call for long-term implantation, but even the present investigation confirms that treatment of collagen in the described manner is a suitable method. Key words: xenograph, arteficial ligament replacement, tendon prosthesis.

[Antibodies to Collagen in the Patients with primary Operation and Reoperation of Endoprosthesis of the Hip Joint.]

Using ELISA method titres were determined of antibodies to collagen of type I, II and III in the serum of the patients who underwent implantation or reoperation of total endoprosthesis of the hip joint. The group of primary operations included mainly patients with osteoarthritis (OA), ankylosing spondyllitistis (AS), rheumatoid arthritis (RA), the group of the reoperated comprised also patients after various traumas of the hip joint. Increased titres were generally found in all patients, however, in the group of reoperated patients the average values were higher than in the patients after primary operations. In the reoperated patients the level of antibodies against all types of collagen monitored was statistically significantly increased in comparison with the control group both prior to and after the surgical operation, mainly in type II. The patients before the primary operation have the levels of antibodies against collagen type II significantly increased in comparison with the controls. The increase found may be caused by the primary articular disease - inflammatory changes, which were found also in decompensated OA. Key words: hip joint replacement, reoperation, collagen, antibodies.

The role of cartilage minor collagens in inducing arthritis

Arthritogenic properties of native types IX, XI, and II collagen were investigated in female Wistar rats. Immunization with native type-XI or -II collagen led to the arthritic reaction in 60% of investigated rats. After boosting, a distinct increase in anticollagen antibodies was observed followed by temperature rise (swelling and redness of affected joints). At the end of the experiment (after 7 weeks) subchondral bone destruction was detectable upon x-ray examination. Histological observation of the affected knee and ankle joints showed progressive destruction of the articular cartilage and subchondral bone accompanied by proliferative synovitis with extensive formation of fibrous tissue found in joints of rats immunized with native type-XI collagen. Immune response to collagen types (determined by ELISA) reached its peak between the 14th and the 21st day. From the acute stage to the chronic stage a decrease of serum anticollagen antibodies was observed to remain constant. Rats immunized with native type IX and denatured type XI collagen did not develop arthritis.

Contribution to the mode of action of univalent gold

Au+ binds to the collagen structure and, therefore, the authors studied the kinetics of the interaction between sodium gold thiosulphate (SGTS) and C1q complement subcomponent, the structure of is partially collagenous. The kinetics was evaluated densitometrically and compared with that of collagen and SGTS. On the basis of those results, the effect of SGTS upon collagen type-II-induced arthritis (CIA) was investigated in Wistar rats. SGTS (20 mg per kg of body weight weekly) was administered i.m. starting i) with the first immunization dose, ii) with the second immunization dose, and iii) after the onset of arthritis. Regardless of the timing of drug administration the manifestation of arthritis was decreased, but the decrease was more expressed in the first two groups. It was concluded that SGTS administration is capable of inhibiting CIA, provided that the drug is applied sufficiently early. Since formation of antibodies to type-II collagen remained unaffected, it is feasible that the mode of action of gold complexes is based mainly on blocking the activation of complement system.

Characterization of an asporogenous mutant of Streptomyces aureofaciens with increased resistance to several aminoglycoside antibiotics

An asporogenous spontaneous mutant of Streptomyces aureofaciens named ASR1 was selected on streptomycin gradient plates. The mutant is very stable and differs in ultrastructure and morphology, it is prototrophic but it lost the ability to grow well on soybean extract medium and produces one-tenth tetracyclines of the parent. The ASR1 mutant has a 3-4-fold increased resistance to streptomycin and is cross-resistant to other aminoglycosides. Comparison of the protein profiles from both strains on SDS gels revealed a very low expression of a 29.5 kDa protein in the ASR1 mutant which is overexpressed in both vegetative cells and spores of the parental strain.

[Possibilities of predicting serum levels of lithium and subsequent correction of its dosage]

The objective of the present work was to evaluate the practicability of several procedures used for prediction of the serum concentration of lithium in a steady state which will make it possible to adjust the dosage in the early period of treatment. The group comprised nine men where prophylactic lithium treatment was indicated on account of maniomelancholy. The authors assessed in each patient the theoretically calculated and actually assessed value of minimal lithium concentrations in a steady state. In all applied predictive methods the predicted values were always higher than the actually assessed lithium concentrations. The least suitable method was that based on individualization of the population average of the velocity constant of elimination. The predictive value of the procedure based on a non-individualized single-point estimate was higher. A statistically significant correlation of predicted and assessed values was provided by the method which, based on two collected samples of lithium serum concentrations, makes it possible to estimate the individual value of the cumulative factor.

[The relation of nucleoli to precancerous conditions of the cervix]

Oestrogens act at the nuclear level. To these steroids also a cancerogenic effect is ascribed. By staining for nuclear structures according to Smetana and Busch the authors proved morphological structures of the nucleolus in vaginal epithelia and in cells from cervical lesions. This applies to solid nucleoli -- which are active, annular nucleoli which are resting and nucleoli which have completed their activity -- micronucleoli. Hyperoestrogenic women have in their vaginal epithelia of the upper third of the vagina more active nucleoli (11.4%) than hypooestrogenic women (2.1%). Women suffering from cervical carcinoma during the menopause have more active nucleoli in the vaginal epithelia (30.8%), as compared with healthy hyperoestrogenic women of productive age. Patients during the menopause with grade III dysplasias have fewer active nucleoli in cervical epithelia than women with cervical cancer (25.0%), however, as compared with hyperoestrogenic women of productive age, much more. A large number of active nucleoli was proved by staining by Smetana's method also in cells taken from cervical lesions carcinoma type and grade III dysplasia in postmenopausal patients. Evaluation of morphological changes of the nucleoli suggests their activity, the activity of the whole nucleolus and is a sensitive indicator of the activity of the whole cell.

Subcellular organization of Streptomyces aureofaciens and overproduction of chlortetracycline

Biosynthesis of chlortetracycline is localized differently under low- and high-production conditions (standard low-production strain and its high-production variant). The experimental evidence was based on the assay of anhydrotetracycline oxygenase in subcellular fractions, ultracytochemical localization and electron-probe X-ray microanalysis of the product in the mycelium. Overproduction of chlortetracycline is closely associated with compartmentation of biosynthetic enzymes and with an efficient export of the antibiotic out of the cell.

A direct-injection reversed-phase liquid chromatographic micromethod for studying the kinetics of terminal reactions of tetracycline biosynthesis

A new micromethod for measuring enzyme-catalyzed reactions was developed. The method involves a number of consecutive direct injections of aliquots of the reaction mixture onto a microbore column and permits the determination of the time dependence of the decrease of substrate or increase of product concentrations. The reactions proceed in a microvial placed in the autosampler, and as the starting volume can be as low as 10 microliters, the requirement for the amount of enzyme is very low. The autosampler backed by the liquid chromatographic software allows automation of the analyses including data processing and easy quantitation of the enzymatic reaction(s). The method was applied to a system of two consecutive terminal reactions of tetracycline biosynthesis in Streptomyces aureofaciens, catalyzed by anhydrotetracycline oxygenase and tetracycline dehydrogenase. The usage of a diode-array detector facilitated the quantification of the reactions as the product and substrate could be monitored at their optimal wavelengths.

[The incidence of antibodies against collagen in patients with juvenile chronic arthritis]

Using the ELISA method, the authors assessed titres of antibodies to collagen type I, II and III in serum of patients with juvenile chronic arthritis (JCA). The results were compared with antibody titres in patients with rheumatoid arthritis (RA). Elevated antibody titres to all collagen types were found, as compared with age-matched controls. The mean titres in patients with RA were higher than in the group with JCA. Investigation of a correlation between the collagen antibody titres and values of the sedimentation rate after one hour revealed a statistical relationship only in collagen type II in patients with RA.

[Experimental models of arthritis induced by various cartilage collagen type]

To laboratory rats of Wistar strain (Ipcv: Wist) native collagenous types of pig cartilage--II, IX and XI and the denatured type XI were administered. The first immunization dose, 0.5 mg collagen per experimental animal, was administered in incomplete Freund adjuvant and the second immunization dose (collagen in solution) followed after 7 days and was administered by the i.p. route. Inflammatory arthritis of the small interphalangeal, metatarsophalangeal and tarsal joints developed between the 11th and 17th day of the experiment in rats immunized with native collagen type II and XI--60% of the animals were affected. The histological findings corresponded to the course of arthritis, however, the articular destructive changes after administration of collagen type XI were more severe than after type II. The changes were evaluated by X-ray and by means of thermovision. The antibody levels against different types of collagen assessed by means of the ELISA test reached peak values between the 13th and 20th day of the experiment. In the group of rats immunized by collagen type IX and the denatured type XI arthritis did not develop. The antibody response in the group of rats immunized with type IX was similar as in the group immunized with types II and XI. Histological examination confirmed some changes in the joints of rats immunized with collagen type IX, while in the joints of rats immunized with denatured collagen type XI no changes were found.

[The effect of a gold complex on experimental arthritis induced by immunization with type II collagen]

Gold complexes are used in the treatment of rheumatoid arthritis for some 60 years by now. The authors used therefore a gold complex, sodium aurothiosulphate (ATSS) to influence the experimental model of arthritis induced by immunization with type II collagen in laboratory rats. To the first group of laboratory rats ATSS was administered concurrently with the first immunization dose, to the second group with the second immunization dose and to the third group in the course of arthritis. ATSS was administered to individual groups every week by the i. m. route, 20 mg/kg body weight. In all three groups a reduction of arthritic symptoms was observed, however, in group three to a much lesser extent than in groups one and two. The results of the experiment indicate clearly that ATSS was able to suppress the development of collagen induced arthritis, if administered not later than with the second immunization dose. As the formation of antibodies against type II collagen was not suppressed, it may be assumed that the activation of the complement system was blocked by the bond of the gold complex with the C1q component. It has been proved already previously that the interaction of C1q with gold complexes is very rapid.

[Comparison of 2 methods for determining antibodies to collagen: the ELISA test and passive hemagglutination]

For the determination of antibodies against collagen in different rheumatic diseases the authors elaborated two serological techniques. It was particularly the passive haemagglutination, which proved to be little sensitive and insufficiently reproducible. Therefore, for the determination of antibodies against collagen the authors introduced the ELISA method as one of the varieties of enzyme immunoanalysis, giving more precise results. Both methods were compared and it has become apparent that the ELISA method is more reliable and more suitable for the determination of antibodies against collagen.

Anticollagen antibodies in patients with juvenile chronic arthritis

Using ELISA antibodies, titres to collagen type I, II and III in sera of patients with juvenile chronic arthritis (JCA) were assayed. Results were compared with titres of patients with rheumatoid arthritis (RA). Increased antibodies titres to all three collagen types were found in comparison with healthy individuals of the same age. Average titres in patients with RA were higher than those of the JCA group. When antibodies titres were correlated with erythrocyte sedimentation rate in 1 hour (ESR/1h) statistical significance was found only in RA group for collagen type II.

Isolation of pure anhydrotetracycline oxygenase from Streptomyces aureofaciens

Anhydrotetracycline oxygenase was purified to homogeneity from Streptomyces aureofaciens, a producer of tetracycline. The enzyme was purified 60-fold in a 40% yield by a two-step procedure using a combination of hydrophobic chromatography and ion-exchange h.p.l.c. Purified anhydrotetracycline oxygenase was homogeneous according to SDS/polyacrylamide-gel electrophoresis, isoelectric focusing, ion-exchange h.p.l.c. on a Mono Q HR 5/5 column and size-exclusion h.p.l.c. on a TSK G 3000 SW column. The enzyme consists of two subunits of Mr 57,500, as determined by SDS/polyacrylamide-gel electrophoresis.

Glucose-6-phosphate dehydrogenase from a tetracycline producing strain of Streptomyces aureofaciens: some properties and regulatory aspects of the enzyme

Glucose-6-phosphate dehydrogenase from Streptomyces aureofaciens exhibited activity with both NAD and NADP, the maximum reaction rate being 1.6 times higher for NAD-linked activity than for the NADP-linked one. The KM values for NAD-linked activity were 2.5 mM for glucose-6-phosphate and 0.27 mM for NAD, and for NADP-linked activity 0.8 mM for glucose-6-phosphate and 0.08 mM for NADP. NAD- and NADP-linked activities were inhibited by both NADH and NADPH. (2'-phospho-)adenosinediphospho-ribose inhibited only NAD-linked activity. The inhibition was competitive with respect to NAD and noncompetitive with respect to glucose-6-phosphate.