Koi herpesvirus (KHV) and KHV disease (KHVD) – a recently updated overview

Over the last years, there has been an enormous increase in the knowledge on koi herpesvirus (KHV), koi herpesvirus disease (KHVD), pathogenesis and virus variants. Different KHV lineages have clearly been identified, possible genomic changes during replication in different cell cultures at different temperatures but also in several hosts have been identified, a persistent stage of infection has been specified and it has been shown that infection with KHV is not host specific at all, but KHVD is. Additionally, it has been shown that it is possible to combat KHVD by immunization with inactivated and attenuated live vaccines using different delivery systems but also to benefit from alternative treatments with e.g. exopolysaccharids obtained from Arthrospira platensis.     

VALSA EUGENIAE IN RELATION TO THE SUDDEN-DEATH DISEASE OF THE CLOVE TREE (EUGENIA AROMATICA)

The sudden-death disease of the clove tree is invariably associated with the fungus Valsa eugeniae. The pathogenicity of this fungus has been investigated experimentally, and it has been shown that it is a primary parasite on mature clove trees, that saplings are resistant to it, and that seedlings are immune. It has been experimentally demonstrated that water-borne spores of the fungus can invade the absorbing and the fibrous roots of the clove tree. The slow-decline disease, which affects clove saplings only, is associated with a slow and progressive root-rot over a period of many years. Valsa is also invariably associated with this disease, which occurs only in areas which have been replanted after the previous stand has been killed by sudden death. It is thought that slow decline is the symptom-expression of Valsa attack on young trees when these still retain some measure of juvenile resistance to it.     

The composition and structure of isolated chromosomes

1. The preparation of isolated chromosomes from liver, kidney, and pancreas has been described. 2. It has been shown that there is no gross cytoplasmic contamination in these preparations. 3. In a microscopic study of isolated chromosomes the same chromosomes have been found in different tissues of the same organism. Since individuality is one of the main characteristics of chromosomes, there can be little doubt that the preparations do, in fact, contain isolated chromosomes. 4. A quantitative study of staining with crystal violet shows that this basic dye competes with histone for the phosphoric acid groups of the DNA in chromosomes. The displacement of histone by protamine has been demonstrated. 5. Preparation of histone-free chromosomes has been described. Removal of histone does not affect the microscopic appearance of chromosomes. 6. The non-histone or residual protein has been prepared from histone-free chromosomes. The quantity of residual protein in a preparation of chromosomes is correlated with the amount of cytoplasm in the cells from which the chromosomes were prepared. 7. The microscopic appearance of chromosomes depends upon the association of DNA with residual protein. 8. Evidence has been given that in a chromosome there are two DNA-containing nucleoproteins; in one DNA is combined with histone, and in the other it is combined with residual protein.     

Thrombophilia and pregnancy

Pregnancy is hypercoagulable state. The field of thrombophilia; the tendency to thrombosis, has been developed rapidly and has been linked to many aspects of pregnancy. It is recently that severe pregnancy complications such as severe preeclampsia intrauterine growth retardation abruptio placentae and stillbirth has been shown to be associated with thrombophilia. Recurrent miscarriage and has also been associated with thrombophilia. Finally, thromboembolism in pregnancy as in the non-pregnant state is linked to thrombophilia. In this review all aspects of thrombophilia in pregnancy are discussed, and also all prophylactic and therapeutic implications.     

Familial juvenile hyperuricaemic nephropathy is not such a rare genetic metabolic purine disease in Britain

Renal disease is rare today in classic adult gout, and gout is rare in renal disease--especially in the young. Here we summarise studies in 158 patients from 31 kindreds diagnosed with familial juvenile hyperuricaemic nephropathy FJHN from a total of 230 kindred members studied in Great Britain. Some patients have been followed for up to 30 years, and allopurinol has ameliorated the progression of the renal disease in all 113 surviving members provided: They have been diagnosed and treated sufficiently early. Compliance with allopurinol treatment and diet has been as important as early recognition. Hypertension has been rigorously controlled. The use of oral contraceptives has been avoided, as has pregnancy in any female with a Glomelar Filtration Rate GFR <70 ml/min. The question arising is: Why is FJHN the most prevalent genetic purine disorder diagnosed in Britain? Is it a lack of awareness which needs to be improved Europe-wide?     

Technique and staining optimization leucoconcentration

In cytometric clinical application, it is important to obtain cell suspensions rapidly with as little cytological alteration as possible. A procedure has been achieved to prepare cell suspensions for flow cytometric analysis. The leucoconcentration technique, first described by Herbeuval for cytologic analysis, has been modified to be applied in cytometry. This technique involves Saponin lysis of red cells of peripheral blood or bone marrow samples that have been previously fixed with picric acid alcohol solution. Cells in suspension are not shifted and tinctorial affinity is not modified. Then cells have been stained with Mithramycin. Each parameter defined by Crissman has been analyzed to define the best staining conditions. The availability of Leucoconcentration with Mithramycin-DNA-staining permits determination of cell cycle with a fine resolution.     

Kinetic co-operativity of monomeric mnemonical enzymes. The significance of the kinetic Hill coefficient

The expression of the kinetic Hill coefficient for a two-substrate, two-product mnemonical enzyme has been derived. Its relation with the gamma coefficient, that is the slope of the reciprocal plots for 1/[A]----O, has been established. The variation of this Hill coefficient, as a function of the second substrate and product concentrations, has been studied theoretically. Whereas the gamma coefficient does not vary as a function of the substrate and first product concentrations, the kinetic Hill coefficient does. If the enzyme is positively co-operative, the Hill coefficient increases upon increasing the second substrate concentration and decreases if the first product concentration is increased. The converse is expected to occur if the enzyme displays a negative co-operativity. The last product may either reverse a positive co-operativity into a negative one or, alternatively, strengthen an already negative co-operativity. The co-operativity generated by the mnemonical model has been compared to the kinetic behaviour of a random model. These two models have been shown to be discriminated on the basis of the departure they show with respect to the Michaelis-Menten behaviour. These theoretical considerations have been applied to previously published data, obtained with wheat germ hexokinase LI. This monomeric enzyme has a negative co-operativity with respect to the preferred substrate, glucose. The Hill coefficient decreases with MgATP concentration, increases with MgADP concentration and decreases with glucose-6-phosphate concentration. This is exactly what is to be expected on the basis of the above theory of kinetic co-operativity.     

Interferon therapy in neoplastic diseases

Three types of interferon preparation (alpha, beta and gamma) have been used in the treatment of tumours in vivo. At the time of writing no information is available on IFN-gamma treatment of tumour patients. Treatments with IFN-alpha and IFN-beta have been undertaken at many clinical centres. Both types of preparation can exert side effects. Both types have also been able to cause regression of certain tumours in individual patients. At our hospital, IFN-alpha has been given to tumour patients over the last decade. Antitumour effects have been registered on patients with juvenile laryngeal papillomatosis, Hodgkin's disease, myelomatosis, ovarian carcinoma, hypernephroma and glioblastoma. Further study is needed on how therapy with IFN should best be undertaken and also how such treatment compares with other treatments of various tumour diseases. IFN therapy should also be combined with other such treatments.     

Characterization of cytosine permeation in Saccharomyces cerevisiae.

Cytosine permeation in Saccharomyces cerevisiae has been studied. Cytosine uptake is mediated by a permease which is also responsible for purines transport. The Km for the transport of various substrates of this permease have been determined. By means of appropriate selective techniques, mutants with altered Km and mutants lacking the permease have been selected. Cytosine transport is active and is inhibited by 2,4-dinitrophenol, an uncoupler of oxidative phosphorylation, and by N-ethylmaleimide, a reagent of--SH group. Internal labeled cytosine is chased by addition of unlabeled cytosine in the medium. These results support the hypothesis of a carrier-mediated transport, with reduced internal affinity, allowing the release and accumulation of cytosine in the inner compartment. The efflux of cytosine from cytosine permease-less cells has also been studied and shows first order kinetics. A diffusion coefficient of 5.7 per 10- minus 8 cm per S- minus 1 has been evaluated for this efflux.     

A complete cleavage map of Neurospora crassa mtDNA obtained with endonucleases Eco RI and Bam HI.

A physical map of Neurospora crassa mitochondrial DNA has been constructed using specific fragments obtained with restriction endonucleases. The DNA has 5 cleavage sites for endonuclease Bam HI, 12 for endonuclease Eco RI and more than 30 for endonuclease Hind III. The sequence of the Eco RI and Bam HI fragments has been established by analysis of partial fragments. By digestion of the Eco RI fragments with Bam HI, a complete overlapping map has been constructed. The position of the largest Hind III fragment on this map has also been determined. The map is circular and the added molecular weight of the fragments is 40 - 10(6), which is in good agreement with earlier measurements on intact DNA, using the electron microscope.     

Proteolysis of Liver Plectin by μ-Calpain

Rat liver plectin was found to be mainly associated with plasma membrane fractions enriched in junctional complexes. The membrane-associated plectin has been partially isolated. Plectin co-purifies with a 200 kDa polypeptide which, on the basis of sequence homology, has been identified as a myosin like-protein. The interaction of μ-calpain with liver plectin has been investigated. Plectin is very sensitive to μ-calpain and is digested to give a fragment of 240 kDa.     

The amino acid sequence of myoglobin from skeletal muscles of red deer(Cervus elaphus)

Red deer myoglobin has been fragmented by restricted tryptic digestion and by treatment with cyanogen bromide. The fragments have been separated by gel permeation. The core peptide derived from cyanogen bromide cleavage have been further digested with trypsin and the resulting peptides have been separated on Dowex 1X2. All fragments have been characterized by their amino acid composition, by determination of their N-terminal sequence using automatic Edman degradation and of their C-terminal sequence following the kinetics of amino acid cleavage by carboxypeptidases A and B. The complete sequence has been found to be identical with the already known sequence of sheep myoglobin except for residue 145 which is Gln in red deer globin and Glu in sheep globin. Reinvestigation of the corresponding sequence in sheep globin has shown that residue 145 of sheep globin is also Gln.     

Cardiac effects of cocaine: a review

Over the past 15 years, there has been a dramatic increase in the abuse of purified cocaine preparations throughout the industrialized world. The potential lethality of the drug is now recognized, and a growing series of case reports indicate that cardiotoxicity may be an important factor in the morbidity and mortality associated with the drug. Acute myocardial infarction is a demonstrated risk both in subjects with and without pre-existent coronary artery disease. The arrhythmogenic potential of cocaine is less clear and appears to have been overemphasized, although several documented cases of ventricular arrhythmia following cocaine use have been reported. Cardiomyopathy and myocarditis associated with cocaine have also been described, but an etiologic relationship is presently inferential. Based upon presumed pathophysiologic mechanisms, beta adrenergic blocking agents are recommended for arrhythmias, and calcium channel blocking agents and/or nitrates for ischemic syndromes related to cocaine. It is emphasized that these recommendations are based upon a paucity of relevant clinical studies, and controlled clinical trials to establish their efficacy have not been performed.     

Construction, assembling and application of a trehalase-GOD enzyme electrode system

Trehalose is a disaccharide important in foods, serving as a glucose source in many and also as an additive in the food preparation. Because of its peculiar physico-chemical properties it plays an important role as preservative in drying and deep-freezing treatments. A new biosensor for trehalose determination has been realized by means of a flow system, based on a reactor in which the trehalase enzyme catalyses its hydrolysis into two alpha,d-glucose molecules, and a GOD (glucose oxidase) amperometric biosensor is employed for the glucose determination. The optimum operative conditions have been laid out and a particular attention has been paid to the immobilization procedure of the two enzymes. The electrode used is of the SPE (screen-printed electrode) type and has been activated with the Prussian Blue (PB) and then assembled using GOD immobilized with Nafion. The reactor has been prepared with the trehalase enzyme chemically immobilized on an Immunodyne ABC membrane. As demonstration of its utility, the biosensor has been tested on a real sample of Boletus edulis mushroom.     

Effects of rho-fluorophenylalanine on the growth of Lactobacillus arabinosus

p-Fluorophenylalanine has been found to be inhibitory to Lactobacillus arabinosus 17-5. This inhibition has been shown to be competitive with phenylalanine but not with tyrosine, and is described by a low antibacterial index, which varies over a range of approximately 1–20, dependent upon the temporal stage of the culture for which the data are employed in calculation.The organism has been found also to adapt readily to the inhibitor. Evidence that this adjustment involves a mutation to a type with a selective advantage in media containing the inhibitor is presented.Under limiting conditions, which have been described, the organism is capable of greater growth in the presence of both metabolite and antimetabolite than in the presence of the same amount of metabolite alone.Discussion of the significance of the results has been presented.     

Activity coefficients of counterions in solutions of diethylaminoethyl dextran hydrochloride

Activity coefficients of counterions in solutions of diethylaminoethyl dextran hydrochloride have been determined. It has been observed that they increase with decreasing concentration of the polyelectrolyte. The experimental values have been compared with those calculated using Oosawa's theory of activity coefficients. The calculated values are higher than those observed, which suggests that the rodlike model on which Oosawa's theory is based is inadequate for the present case. Activity coefficients of counterions of some solutions containing NaCl and KC1, respectively, have also been determined. It has been found that the additivity rule for activity of counterions applies for these solutions.     

Novel frameworks as a source of high-affinity ligands

The past year has seen further maturation of the techniques used to display populations of proteins and peptides and to select members with desired properties. Many protein domains have now been displayed on genetic packages, diverse populations have been made, and binders with specific useful properties have been selected. Affinity maturation has been demonstrated so that binding in the low nanomolar to subnanomolar range by non-antibodies is now achievable.     

DTNB对人肌肌酸激酶不可逆抑制作用的研究

本文研究了DTNB对人肌肌酸激酶的不可逆抑制作用.研究结果表明,与兔肌肌酸激酶不同,人肌肌酸激酶分子中有四个可反应SH.用邹承鲁作图法定量处理结果表明,在这四个可反应的SH中,有一个快反应SH,两个慢反应SH且这两个慢反应SH是酶的必需基团,此外还有一个反应很慢的SH.用邹承鲁提出的在抑制剂存在条件下,酶活性不可逆改变动力学方法,测定了一系列动力学常数,并对DTNB的作用机制进行了探讨.     

Electrokinetic energy conversion studies of aqueous solution of urea, glucose and their mixtures across urinary bladder membranes

Electrokinetic studies of aqueous solutions of urea, glucose, urea-glucose mixture (urea concentration increasing and glucose fixed) and glucose-urea mixture (glucose concentration increasing and urea concentration fixed) have been carried out across urinary bladder membranes of goat. Results have been analysed using methodology of non-equilibrium thermodynamics. It has been found that energy conversion maxima and degree of coupling for mixtures is higher than urea and glucose solutions. It has also been found that in the case of urea-glucose mixtures, the value of maxima and degree of coupling first decreases and then increases with increase in concentration while in the case of glucose-urea mixture, the trend is not definite. With urea solutions only, both these values increase with increase in concentration. It has been observed that energy conversion maxima and degree of coupling for urine is much higher as compared to other permeants. It appears that second order phenomenological coefficient L112 is related with degree of coupling (qe) as the trend of two is quite similar.