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By reaction with arylhydroximoyl chlorides, 2,3,4,6-tetra- O -acetyl-1-thio-β- d -galactopyranose was converted to the corresponding β- d -galactopyranosyl-thiohydroximates, which gave predominantly (1 S )- d -galactopyranosylidene-spiro-oxathiazoles on illumination in the presence of NBS. Conventional O -deacetylation of both thiohydroximates and oxathiazoles gave weak inhibitors of E. coli d -galactosidase ( K i 1.1–11.1 mM).

Lower extremity inequality is a common problem in everyday orthopaedic practice. The leg discrepancy can lead to variety of other problems, i.e., spinal problems. Surgical intervention is very demanding and requires patient compliance. Wagner’s and Ilizarov’s elongation technique are most commonly used worldwide, but it gives satisfactory results only in a long period of time and as we know there could be several inconvenient outcomes. Our idea aims at shortening this time period, and avoiding some of the inconvenient outcomes. Unfortunately we do not have the opportunity to go further in our investigations, but we hope that someone interested in this field will have an idea which would make continuation possible.

Current literature has increasingly emphasized the problem of derotation in scoliotic deformities. The Cotrel-Dubousset (CD) principle as a means of correcting rotation has been questioned by various authors. This paper aims to draw attention, using algebraic methods, to the importance of the remaining rotational deformities, and to suggest the introduction of the notion 'rotational balance'.

3-Oxagranatane derivatives have been synthesized from dialdehydes obtained by the periodate oxidation of d -glucopyranosides. Reduction of the carbonyl group and removal of the substituents afforded bicyclic iminosugar analogs.

Microfiltration membranes made from polytetrafluorethylene (PTFE) have been successfully used for the separation of oily waste waters by membrane coalescence, but filtration of the oily waste waters with high emulsifier content have not yet been investigated. Our aim was to examine the effect of emulsifier content on membrane coalescence on this type of membrane, and to investigate the effect of surfactant addition on oil retention and filtration parameters. It was found that the oil content of the emulsion can be separated with MF PTFE membranes. Efficiency of the retention depends on the concentration of emulsion: increasing concentrations resulted in an increased retention. The addition of coagulant also affected filtration parameters: higher coagulant concentrations resulted in a significant increase of the flux, while the retention marginally decreased.

The coding sequence of the mature cyanogenic beta-D-glucosidase (beta-D-glucoside glucohydrolase, EC 3.2.1.21) (linamarase) of Manihot esculenta Crantz (cassava) was cloned into the vector pGEX-2T and expressed in Escherichia coli. The bacterial chaperonin GroEL [Braig, Otwinowski, Hedge, Boisvert, Joachimiak, Horwich and Sigler (1994) Nature (London) 371, 578-586] was found to be tightly associated with the fusion protein and co-purified with it. In the presence of excess MgATP, release and folding of the fusion beta-glucosidase were demonstrated by a fast increase in both linamarase and p-nitrophenyl-beta-D-glucopyranosidase activity at a low protein concentration. A slow endogenous folding process was also detected by activity measurements. Michaelis constants (Km) and the ratio between the maximal velocities and efficiency constants (Vmax., Vmax./Km) for the hydrolysis of the natural substrate, linamarin, and p-nitrophenyl beta-D-glucopyranoside (PNP-Glc) by the recombinant protein were found to be almost identical with those of the native glycosylated plant enzyme [Keresztessy, Kiss and Hughes (1994) Arch. Biochem. Biophys. 314, 142-152]. Molecular dissociation constants for the free enzyme (pK(E)1, pK(E)2) obtained with linamarin and PNP-Glc, and the enzyme substrate complexes (pK(ES)1, pK(ES)2) were also in accordance with that of the original protein. The reactive substrate analogue N-bromoacetyl beta-D-glucosylamine inactivated the fusion enzyme according to pseudo-first-order kinetics with first-order rate constant (k1=0.007 min-1) and apparent inhibition constants (k1=20 mM) comparable with those of the plant protein [Keresztessy, Kiss and Hughes (1994) Arch. Biochem. Biophys. 315, 323-330]. In comparison with the native glycosylated plant protein, the recombinant protein was, however, found to be extremely sensitive to proteolysis and misfolding.

Urinary N-acetyl-beta-D-glucosaminidase activity was assayed in fullterm and preterm polycythemic neonates, in preterm infants with hypoxia, and in healthy newborns. There were no significant differences between fullterm and preterm babies or between appropriate for gestational age and small for gestational age neonates in the normal group. N-acetyl-beta-D-glucosaminidase excretion on the first day of life was significantly raised in polycythemic newborns (P less than 0.01). Fourteen days after partial plasma exchange the enzyme activity returned to normal. N-acetyl-beta-D-glucosaminidase activities in preterm babies with respiratory distress syndrome were significantly (P less than 0.01) raised on the 1st, 2nd, 4th days and fell sharply to the 14th day. N-acetyl-beta-D-glucosaminidase isoenzyme studies revealed that urine samples taken from preterm babies with respiratory distress syndrome in the first week after birth contained increased amounts of intermediate and B isoenzyme forms while there was a concomitant reduction in the amount of the A form present.

The influence of the transition metals T = Ti, V, Cr, Mn, Co, Ni, Ru, Os, Pd on the Mossbauer characteristics and corrosion resistance of Fe 80 T 3 B 17 metallic glasses was studied. It was found that the additives improving magnetic properties decrease corrosion resistance and vice versa. The changes of the isomer shift are interpreted in terms of changes of the electronic structure caused by alloying with transition metals.

Although still there are Klebsiella strains which do not harbour plasmids and produce constitutive chromosomal β-lactamases, recently clinical isolates were found in ever increasing numbers carrying mainly TEM-, CARB- and OXA type R-factors. We selected four chromosomal cephalosporinase producing Klebsiella strains to study the p I values of the enzymes and their simultaneous separability from accompanying proteins by chromatofocusing techniques. We compared p I values of the pure and the crude preparations: K. pneumoniae Kl SC 10436: p I pure = 6.4, p I crude = 6.42; K. aerogenes Kl 1082 E: p I pure = 6.5, p I crude = 6.5; K. oxytoca 1082 E: p I pure = 6.42, p I crude = 6.4; K. oxytoca 20: p I pure = 7.62, p I crude = 7.6. Excellent agreement of the p I values among each other, but occasional differences with those obtained by analytical isoelectrofocusing are attributed to methodological diversities and to the presence of satellite enzymes, known to exist in Klebsiella .

A method was developed for determination of the three neomycin components, neomycin A, B and C using silica gel thin-layer chromatography with detection with p-dimethylamino benzaldehydeninhydrine reagent and videodensitometry. The method was used to monitor the composition in different stages of production. The results obrained were compared with that of biological determination.

Hydrolysis of 1,2- O -isopropylidene-3,5-di- O -methyl-α- d -glucofuranose by strong acid yielded 3,5-di- O -methyl- d -glucofuranose ( 6 ) and its 1,6-anhydride ( 10 ). The mechanism of the reaction giving 10 is discussed. On treatment with a catalytic amount of sodium methoxide, 1,2,6-tri- O -acetyl-3,5-di- O -methyl- d -glucofuranose ( 8 ) gives the 6- O -acetyl derivative, whereas complete deacetylation, and subsequent isomerization to the d -fructose derivative 16 , takes place in the presence of 0.1 m sodium methoxide. The structure of 16 was proved both chemically and spectroscopically. Reduction of 6 or 8 with a borohydride afforded 3,5-di- O -methyl- d -glucitol. 2

The role of exposed tyrosine side-chains in enzyme-catalyzed reaction by sweet almond emulsin beta-D-glucosidase (beta-D-glucoside glucohydrolase, EC 3.2.1.21) has been studied using N-acetylimidazole as the specific reagent. The changes in activity, binding affinity and kinetic parameters (Km, V) as a result of acetylation of the phenolic hydroxyl groups have been determined. The acetylation increased the Km values of both beta-glucosidase and beta-galactosidase activities, whereas V remained unchanged. Similarly, the binding affinity for immobilized phenyl beta-D-glucopyranoside decreased appreciably. After the removal of the acetyl groups the enzyme regained 96% of the original activity. It is concluded that the tyrosine moieties, located in the active centre of the enzyme, have both glucoside and galactoside binding functions.

N-Acetyl- d -(−)-penicillamine as a stable second-generation biospecific affinity ligand has previously been suggested for purification of Bacillus cereus 569/H β-lactamase I. A complex spacer arm is coupled with the matrix by using epichlorohydrin and phloroglucinol doubly activated with divinyl sulphone in the meta position. Coupling of d -(−)-penicillamine ligand resulted in an active affigel. However, we found that two affinity ligands in close proximity prevents simultaneous binding of two penicillinase molecules, therefore one ligand is superfluous. Our results show that: (1) shortening the spacer arm by direct activation of the matrix with divinyl sulphone is satisfactory to produce the affinity material with N-acetyl- d -(−)-penicillamine; (2) incorporation of 15 μmol of N-acetyl- d -(−)-penicillamine per ml of wet Sepharose 4B satisfies the maximum binding capacity requirements of the affigel (about half of the originally incorporated amount of ligand); (3) our simplified affinity adsorbent is generally applicable for large-scale purification of penicillinases to homogeneity from various bacterial sources by the convenient batch method without prior concentration of these enzymes; (4) reacetylation for four/five times can regenerate the original binding capacity of the affigel.

Partially purified linamarase from Trifolium repens (genotype Lili acac ) plants was kinetically characterized. Kinetic evidence was found to support the assumption that this cyanogenic β- d -glucosidase has a broad substrate spectrum. p -Nitrophenyl-β- d -xylopyranoside and p -nitrophenyl-α- l -arabinopyranoside substrates bound almost as tightly to the active center of the enzyme as the glucono(1 → 5)lactone transition-state analog inhibitor. Substrate specificity investigation also indicated that positions C-4 and C-6 on the pyranoside ring play an essential role in both substrate orientation and splitting. Recently very similar kinetic characteristics were reported on some mammalian cytosolic β- d -glucosidases and a possible physiological interpretation of this coincidence is discussed. Inhibition studies with glucono(1 → 5)lactone revealed that the carbohydrate moiety of each substrate attached to the same binding site in the active center. Inhibition experiments with 1-thio substrate analogs demonstrated that the aglycon and the angular arrangement around the glycosidic linkage were the major determinants in the observed substrate specificity.

Methods by means of which it can be decided whether the dissolution of a metal via several consecutive charge-transfer steps is a two or a three-step mechanism are surveyed. The information relevant to answer this question is furnished by the rate constants of the second reaction step. These rate constants can be calculated from polarization curves, or form data gathered using a rotating ring-disc electrode in the experiments. Using the methods described, we studied the anodic dissolution of indium in aqueous acidic pechlorate solution. It was found that the anodic dissolution of indium, under the conditions studied, takes place in three consecutive one-electron steps.

Eine Vorrichtung zum Messen der mit Sauerstoffreduktion verbundenen Korrosionsgeschwindigkeit ist beschrieben. Nach dem Grundprinzip des Verfahrens wird der wahrend der Korrosion verbrauchte Sauerstoff durch elektrolytisch hergestellten Sauerstoff ersetzt. Die zur Herstellung des Sauerstoffs benotigte Ladungsmenge ist bequem mesbar und gibt gleichzeitig Aufschlus uber das Fortschreiten der Korrosion. Apparatus for continuous measurement of corrosion rate by oxygen reduction An equipment is described for continuous measurement of corrosion rates by oxygen reduction. The basic principle involves the measurement of quantity of oxygen produced in electrolysis to compensate the quantity consumed during the corrosion. The quantity of electricity consumed for oxygen evolution can be conveniently measured and thus shows the progress of the corrosion process.

1,2:5,6-Di- O -isopropylidene- d -glucitol was converted via its 1,4-dimethanesulfonate into the 1-azido-4-methanesulfonate which, after deprotection and treatment with barium hydroxide, afforded a 9:1 mixture of the corresponding 3,4- and 4,5-anhydro derivatives. Reduction of this mixture by transfer hydrogenation using ammonium formate in methanol and Pd/C as catalyst afforded 1,4-dideoxy-1,4-imino- d -glucitol ( 4 ), the structure of which was proved after acetylation by 1 H-n.m.r. spectroscopy. Compound 4 is a potent α- d -glucosidase inhibitor ( K i 7 × 10 −4 m ) and a less potent β- d -glucosidase inhibitor ( K i 1.25 × 10 −4 m ), and inhibits β- d -galactosidase non-competitively.

1,2:5,6-Di- O -isopropylidene- d -glucitol was converted via its 1,4-dimethanesulfonate into the 1-azido-4-methanesulfonate which, after deprotection and treatment with barium hydroxide, afforded a 9:1 mixture of the corresponding 3,4- and 4,5-anhydro derivatives. Reduction of this mixture by transfer hydrogenation using ammonium formate in methanol and Pd/C as catalyst afforded 1,4-dideoxy-1,4-imino- d -glucitol ( 4 ), the structure of which was proved after acetylation by 1 H-n.m.r. spectroscopy. Compound 4 is a potent α- d -glucosidase inhibitor ( K i 7 × 10 −4 m ) and a less potent β- d -glucosidase inhibitor ( K i 1.25 × 10 −4 m ), and inhibits β- d -galactosidase non-competitively.

An isoenzyme of glucosidase- isolated from sweet almond emulsin - and composed of a β-D-glucosidase, a β-D-galactosidase and a β-D-fucosidase, has been shown to possess β-D-xylosidase activity, as well. On the basis of the following results it has been concluded that the β-D-glucosidase and β-D-galactosidase activities reside in one catalytic site, but there are two kinetically distinst binding sites in the active center: 1./D-Glucono-1,5-lactone is shown to excert competitive inhibition on the hydrolysis of β-D-glucopyranoside and non-competitive inhibition on the hydrolysis of β-D-galactopyranoside. 2./ D-galactono-1,5-lactone competitively inhibits the hydrolysis of β-D-galactopyranoside, but possesses non-competitive inhibition on the hydrolysis of β-D-glucopyranoside. 3./ When the enzyme is incubated with two p-nitrophenyl glycoside substrates at or above their respective Km values, the rate of p-nitrophenol formation is not additive but rather it is equal to the value calculated from the individual Km values and relative maximum rates.

Tanulmányunk első részében a nemzeti karakterrel foglalkozó reformkori kutatások történelmi alapjait, kiváltó okait, előzményeit vizsgáltuk korabeli írások gazdag felhasználásával. Majd szót ejtettünk a kifejezés használata körüli bizonytalanságokról, s végül a téma néhány etnikai/származási/faji vonatkozásáról is. A mostani, második részben először a nemzeti karakter rokon értelmű kifejezéseiről lesz szó, majd a fő komponenseivel kapcsolatos ún. egy- és többtényezős elméletekről. Végül arra az ugyancsak izgalmas kérdésre is választ keresünk, hogy a reformkori „publicisták” a nemzeti karaktert és annak komponenseit állandóaknak, időtállóaknak tekintették-e, vagy ellenkezőleg, az idő múlásával változóaknak, netalántán megszűnőeknek. Ezzel az írással szeretném köszönteni kedves kollégáimat, a most 80 esztendős Kaló Ferencet és Kertész Istvánt.

In carbon-depleted cultures of Penicillium chrysogenum, age-related chitinases were shown to play a crucial role in both autolysis and fragmentation as indicated by in vivo enzyme inhibition experiments using allosamidin. This pseudotrisaccharide even hindered significantly the outgrowth of new hyphal tips from the surviving yeastlike fragments after glucose supplementation. The antifungal effect of allosamidin on autolyzing P. chrysogenum mycelia was fungistatic rather than fungicidal. In growing hyphae, membrane-bound microsomal chitinase zymogen(s) were detected, which may be indicative of some compartmentalization of these hydrolases. Later, during autolysis, no zymogenic chitinase was detected in any enzyme fraction studied, including microsomes. These observations may explain the different sensitivity of growing and autolyzing mycelia to allosamidin. Chitinases taking part in the age-related fragmentation of hyphae and the outgrowth of surviving hyphal fragments seem to be potent targets for future antifungal drug research.