Preparation of the myristoylated and nonmyristoylated form of recombinant recoverin in E. coli cells and comparison of their functional activity]

Numerous data strongly suggest the involvement of cytokines and the matrix metalloproteinase collagenase (MMP-1) in the pathogenesis of periodontitis. Recently, we have demonstrated that, upon culturing under the influence of IL-1 alpha + EGF, a large amount of inactive procollagenase (MMP-1) is stored in the extracellular matrix of periosteal tissue. We now show that this endogenous reservoir of proenzyme can be operative after activation with plasmin and is able to induce a rapid and almost complete breakdown of the collagenous extracellular matrix. The level of collagen degradation following activation showed a strong correlation with the amount of proenzyme that was incorporated in the tissue. The highest level of degradation (70% of the total amount of collagenous proteins) was found with the IL-1 alpha + EGF-treated explants, followed by those treated with IL-1 alpha alone (35%). Explants cultured with EGF or in the absence of cytokines, containing only small amounts of procollagenase, showed little collagen breakdown following plasmin activation (7%). Inhibition of metalloproteinases by EDTA, or blockage of plasmin by PMSF, prevented the degradation in all explants irrespective of the amount of proenzyme present in the tissue. Our findings demonstrate that endogenous proenzyme stored in a native connective tissue matrix can be activated at a later time interval which results in a massive breakdown of the tissue. This study shows a possible pathway of collagenase-induced breakdown without recent de novo synthesis of the enzyme. Such a sequence may be operative in chronic inflammatory diseases, such as periodontitis, where production of procollagenase under the influence of cytokines spans a longer time period, whereas breakdown is often characterized by a cyclic behaviour.     

Molecular mechanisms in the control of limb regeneration: the role of homeobox genes

The Ca2+ sensitivity of cardiac myofibrillar force production can be decreased by acidosis or inorganic phosphate (P(i)) and increased by caffeine. To investigate whether the source of tissue influences the potency of these agents, we compared the actions of acidosis (change of pH from 7.0 to 6.2), P(i) and caffeine (both 20 mM) on force production of skinned cardiac muscles from adult ventricle, adult atrium and neonate ventricle of the rat. Maximum Ca(2+)-activated force was reduced by all three interventions and the responses of the different muscle types to a given intervention were similar. Acidosis reduced myofibrillar Ca2+ sensitivity by 1.09 and 1.04 pCa units in adult ventricle and atrium, respectively, and P(i) reduced it by 0.19 and 0.22 pCa units. However, each effect was only one-third as great in the neonate ventricle, which showed falls of 0.33 pCa units for acidosis and 0.06 for P(i). In contrast, caffeine raised the Ca2+ sensitivity by the same amount (approximately 0.4 pCa units) in all three muscle types. The differential effect between adult and neonate seen with both acidosis and P(i) suggests some similarity in the mechanisms by which these factors decrease Ca2+ sensitivity. In contrast, the equal effects of caffeine on neonate and adult suggests that caffeine acts by a completely different mechanism. The lower pH- and P(i)-sensitivity of the neonatal ventricle can help to explain why neonatal and adult myocardium exhibit differential force responses to ischaemia (or hypoxia alone).     

An oxazine reagent for derivatization of carboxylic acid analytes suitable for liquid chromatographic detection using visible diode laser-induced fluorescence

This study reports the use of Nile Blue, an oxazine dye, as a derivatization reagent that fluoresces in the far-red spectral region and is suitable for derivatization with carboxylic-acid-containing analytes. Model carboxylic acid analytes such as benzoic acid, acetic acid, phenylacetic acid and hexanoic acid have been reacted as acid chlorides to form Nile Blue derivatives. The synthesis product of the Nile Blue benzoic acid derivative was confirmed using electrospray-mass spectrometry, infrared spectrometry, 1H and 13C nuclear magnetic resonance, reversed phase liquid chromatography (RP-HPLC), normal phase-thin layer chromatography, and spectral characterization. The synthesized Nile Blue derivatives, separated from reaction by-products with RP-HPLC, all demonstrated an approximately 10-fold drop in molar absorptivity and relative quantum yield. In addition, a 40 nm increase in Stokes shift was observed. A portion of the fluorescence was regained through post-column ionization of the Nile Blue benzoic acid derivative at pH 12. A RP-HPLC limit of detection of 88.25 fmol on column has been reported with conventional fluorescence detection-post-column ionization of the Nile Blue benzoic acid derivative. A limit of detection of 1.99 fmol on column (3.98 x 10(-11) M) has been demonstrated for the Nile Blue benzoic acid derivative with the use of a laboratory-constructed visible diode laser fluorescence detector.     

HLA class-I and class-II antigen association in rheumatoid arthritis at Varanasi, India

We examined the localization of phosphotyrosine (p-Tyr)-modified proteins in the normal corneal epithelium using affinity-purified rabbit anti-p-Tyr antibody. Normal rat cornea was fixed and semi-thin and ultra-thin frozen sections were prepared. Immunofluorescence microscopy showed that p-Tyr was distributed along the cell membrane of the corneal epithelium. Immunogold electron microscopy revealed that the labeling is exclusively localized in the desmosomes and hemidesmosomes. A fraction enriched with desmosomes was extracted from the bovine corneal epithelium and examined by Western blotting. Immunoblotting for p-Tyr showed eight prominent bands (290, 200, 190, 115, 85, 62, 50, and 47 kD) in the desmosomal fraction. The enrichment of p-Tyr in desmosomes and hemidesmosomes of the corneal epithelium suggests that these cell-to-cell and cell-to-substrate junctions are involved in signal transduction.     

The interaction of peripheral blood leukocytes with alpha1-acid glycoprotein, its carbohydrate chains and neoglycoconjugates

The interaction of human peripheral blood leukocytes with alpha 1-acid glycoprotein (AGP), its glycoforms as well as neoglyco-conjugates representing carbohydrate chains of AGP or its fragments was studied by flow cytometry. It was shown that the main target cells for AGP as well as for conjugates of its carbohydrate chains with polyacrylamide (PAA) are monocytes and polymorphonuclear leukocytes but not lymphocytes. The interaction of AGP with monocytes and granulocytes are mediated by its carbohydrate chains: the binding of AGP with cells was inhibited by AGP, AGP oligosaccharides as well as conjugates of oligosaccharides and its fragments with PAA. The data obtained show the existence of monocyte (and granulocyte) receptors which interact with complex type sialooligosaccharides of AGP.     

The intra-aortic antibacterial therapy of wounded patients with gunshot meningoencephalitis

The original decision of permanent introduction of antibacterial means to tissues of brain at gunshot meningoencephalitis is offered. For antibacterial therapy the intra-aortal catheter with diameter of 2,5 mm (through a.femoralis) was introduced. After washing the catheter by solution of crystalloid with heparin the various combinations of preparations in 5% solution of glucose were introduced: cephalosporin--8 g/day; hentamicin and brumacilin--240 mg/day accordingly, amicacin--1500 mg/day. Speed of introduction--20-50 mg/h, total volume--500 ml. The catheter was in aorta not more than 10 days, maximum--14 days. A described technique was applied in Burdenko Main Military Clinical Hospital on 34 wounded in head. At computer tomography of brain of all wounded intracranially the splinters and bullets were revealed, clinically--meningoencephalitis. Foreign bodies have been extracted after cupping of clinical and laboratory signs of meningoencephalitis. The authors consider, that the technique is effective not only at wounds of brain, but also at suppurative meningoencephalitis of other etiology.     

Enterosorption in ulcerative lesions of the gastrointestinal tract with concomitant intestinal dysbacteriosis

Adjuvant use of enterosorbents in combined therapy of gastroduodenal ulcers (158 patients), nonspecific ulcerative colitis with intestinal dysbacteriosis was assessed. Enterosorption in combined therapy of gastrointestinal diseases with dysbacteriosis potentiated positive effect. The highest benefit of enterosorption occurs in intestinal affections (nonspecific ulcerative colitis, irritable bowel-syndrome, chronic enteritis, colitis). In gastroduodenal ulcer lignin sorbent (polyfepan) is preferable. Polyfepan acted positively on intestinal dysbacteriosis through eliminating Escherichia with hemolyzing properties and enterococci, by reducing lack of bifidobacteria.     

Isolation of a novel Helicobacter species, Helicobacter cholecystus sp. nov., from the gallbladders of Syrian hamsters with cholangiofibrosis and centrilobular pancreatitis

A filamentous, gram-negative, motile bacterium with a single polar sheathed flagellum was isolated from gallbladders of hamsters with cholangiofibrosis and centrilobular pancreatitis. Bacteria grew under microaerophilic conditions at 37 and 42 degrees C, were oxidase, catalase, arginine aminopeptidase, and L-arginine arylamidase positive, reduced nitrate to nitrite, were resistant to cephalothin, and exhibited intermediate susceptibility to nalidixic acid. Sequence analysis of the 16S rRNA gene indicated that the bacterium was a novel member of the Helicobacter genus, most closely related to Helicobacter pametensis. We propose to name this bacterium Helicobacter cholecystus. In epidemiologic studies, isolation of H. cholecystus correlated strongly with the presence of cholangiofibrosis and centrilobular pancreatitis; however, further studies are needed to define the role of this bacterium in pathogenesis.