In situ localisation of beet necrotic yellow vein virus (BNYVV) in rootlets of susceptible and resistant beet plants

Summary Mechanisms of resistance to beet necrotic yellow vein virus (BNYVV) were studied by comparing the multiplication and distribution of BNYVV in root tissue of some beet accessions. Seedlings were infected either by soil containing resting spores ofPolymyxa betae with BNYVV, or by a viruliferous zoospore suspension. With both inoculation methods high virus concentrations were obtained in rootlets of the susceptible cultivar Regina. Using infested soil, low virus concentrations were found in the partially resistant cultivar Rima and in the resistant accessions Holly and WB42. When a zoospore suspension was used, similar virus concentrations occurred in Rima and Holly as in Regina, while a low virus concentration was found in WB42. By in situ localisation studies, using immunogold-silver labelling, virus was detected in Regina after infection by soil or a zoospore suspension, but it could only be detected in the resistant accessions after infection by a zoospore suspension. In rootlets of Regina, Rima and Holly, virus was found in the epidermis, cortex parenchyma, endodermis, and interstitial parenchyma, but in general not inside the vascular tissue. In WB42 the virus, occurring in small aggregates, seemed to be restricted to the epidermis and some cortex parenchyma cells. Comparing both the multiplication and distribution of BNYVV in rootlets of the accessions studied, it is concluded that the virus resistance mechanism in Rima and Holly is different from that in WB42.     

Lichtmikroskopische Untersuchungen über die Entwicklung vonTheileria annulata (Dschunkowsky und Luhs, 1904) inHyalomma anatolicum excavatum (Koch, 1844)

Summary Fully differentiated kinetes, average length 17.6m, appeared in the haemolymph of engorged nymphs usually 17 to 20 days after repletion. Kinetes were observed at first in the salivary glands on day 18 after repletion. The kinetes then transformed into fission bodies of about 10m in diameter, mainly in type III alveoli and less frequently in type II alveoli. The fission bodies grew up to a size of about 20m after several divisions of their nucleus. At this time the ticks moulted and no further development occurred until activation. Shortly before infestation the salivary glands began to proliferate, and rapid growth of the fission bodies was observed, especially in young ticks where development of infective particles (sporozoites) was concluded within two days. Development in feeding adult ticks apparently occurred in four major steps: (1) Division of primary fission bodies (sporonts) into numerous secondary fission bodies (primary sporoblasts), (2) division of secondary fission bodies into tertiary fission bodies (secondary sporoblasts), (3) production of particles (sporozoites) by tertiary fission bodies and release of particles into the saliva, and (4) degeneration of fission bodies and their host cell but further release of particles.The host cell was stimulated to giant growth, thus its diameter increased, on average, from 15 to 110 m. Heavy infections resulting from parasitaemias of >40% caused disease and mortality in the tick population. Development was much retarded by aging. In ticks starved for six months sporozoites did not develop before day five to seven of infestation. Sporozoites may not develop at all in six to nine month old female ticks during the infestation period. The significance of the described developmental stages ofT. annulata was discussed and a sexual generation postulated. The hypothetic development ofT. annulata in its tick vector was illustrated.

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Gefördert von der Deutschen Forschungsgemeinschaft (DFG)     

Oligoclonal interspecific origin of ‘North Indian’ and ‘Chinese’ sugarcanes

Sugarcanes consist of several groups of complex polyploid forms. The origin of North Indian and Chinese sugarcanes (referred to as S. barberi and S. sinense) was investigated using genomic in-situ hybridization (GISH), detection of species-specific repeated sequences and RFLP. GISH proved their interspecific hybrid origin. Together with the distribution of species-specific repeated sequences and earlier RFLP data, the results show that both taxa are derived from interspecific hybridization between S. officinarum and S. spontaneum and that no other genus has been directly involved. RFLP indicates that the clones are clustered into a few groups, each derived from a single interspecific hybrid that has subsequently undergone a few somatic mutations. These groups correspond quite well with those already defined based on morphological characters and chromosome numbers. However, the calculated genetic similarities do not support the existence of two distinct taxa. The North Indian and Chinese sugarcanes represent a set of horticultural groups rather than established species.     

Induced histidine decarboxylase in endotoxic shock: Identification of the enzyme in rat liver and influence of its inhibitors on survival parameters

The hypothesis of a causal relationship between a progressive and unrestrained increase of tissue histamine formation by activation of an inducible histidine decarboxylase (HDC) and lethality in endotoxic shock (Schayer's induced histamine concept) was tested in a standardized rat endotoxic shock model.Initial enzyme identification studies in the rat shock liver (8 hrs after endotoxin challenge) clearly demonstrate that the induced histidine decarboxylase is an acid (specific) HDC. The succeeding randomized, controlled study with appropriate inhibitors of the enzyme, -methyl-histidine (competitive inhibitor) and -fluoromethyl-histidine (irreversible inhibitor) using doses of 2, 20 or 100 mg/kg showedno significant effect on the survival rate of rats in endotoxin shock. The survival rate of the non-treated endotoxin control group (NaCl) was 25%; all methylprednisolone treated rats (50 mg/kg) survived.Thus, the induced histamine isnot a predominant factor (necessary or sufficient determinant) for the lethal outcome in rat endotoxic shock. The protective effect of MP isnot predominantly due to the inhibition of the induced histidine decarboxylase. The use of HDC-inhibitors as the appropriate instruments for evaluation of the significance of this mechanism is discussed.Clinic of General Surgery, City Hospital Sieburg.     

The influence of display characteristics on active pursuit and passively induced eye movements

Summary A series of experiments has been conducted on human subjects to examine the effect of the movement of small targets located in the peripheral visual field on oculomotor response. Subjects were presented with either a single centrally positioned target or a pair of targets displaced at angles of ±5°, ±10° and ±20° from centre. Target movement was in the horizontal plane, the paired targets always moving in unison. The stimulus waveform consisted of either a sinusoidal or random target motion encompassing a frequency range from 0.1 to 4 Hz with an angular displacement of ±3.5°. Subjects made two types of response. First they were instructed to follow the single target or the centre point of the paired targets. In this active pursuit condition the gain of slow-phase eye velocity progressively decreased as the moving targets were moved from the central position to the most peripheral location (±20°). Secondly, subjects were required passively to ignore the target movement by staring blankly ahead. During this passive response nystagmic eye movements were induced for which the slowphase eye velocity also decreased with increasing target eccentricity, but the gains were always less than those induced during active pursuit. The frequency characteristics of the passive response were very similar to those of the active response, breaking down at frequencies beyond 1 Hz. The ability to suppress the passive response was also investigated by the presentation of a tachistoscopically illuminated earth-fixed target. The response was found to decline as the interval between presentations of the fixation target was decreased from 3000 ms to 100 ms. It is suggested that the passive response originates from a basic velocity drive to the oculomotor system resulting from image movement across the retina. This velocity drive may be cancelled with adequate fixation but must be enhanced to accomplish desired eye velocity during active pursuit.     

Characterization of internal DNA-binding and C-terminal dimerization domains of human centromere/kinetochore autoantigen CENP-C in vitro: role of DNA-binding and self-associating activities in kinetochore organization

Human centromere protein C (CENP-C), a chromosomal component of the inner plate of kinetochores, was originally identified as one of the centromere auto-antigens. In a previous study, we showed that it possesses DNA-binding activity in vitro. Recently, centromere-binding activity was suggested at the C-terminal region in vivo. However, little is known about the role of CENP-C in kinetochore organization. Here, to characterize its biochemical properties, three separate antigenic regions of human CENP-C were expressed in Escherichia coli, affinity purified and used in South-western blotting and chemical cross-linking analyses. We found that the internal DNA-binding domain was composed of two kinds of elements: the core and two flanking stabilizing elements that support the activity. When cross-linked with disuccinimidyl suberate (DSS), the N-terminal region produced the ladder bands of dimerand tetramer: the C-terminal region exclusively produced the dimer band, whereas the internal region was not affected at all. Dimer formation at the C-terminus in the native state was also indicated by gel filtration and the presence of conformation-specific autoantibodies in the patient's sera. These results suggest that human CENP-C consists of three functional units required for kinetochore assembly: a putative N-terminal oligomerization domain, an internal DNA-binding domain and a C-terminal dimerization domain.This revised version was published online in November 2005 with corrections to the Cover Date.     

Expression of estrogen receptors-α and -β in primary breast neoplasms and tumors exposed to neoadjuvant hormonal therapy

We studied the content and expression of mRNA for estrogen receptors receptors- and - in breast tumors before and after 3-month neoadjuvant hormone therapy with antiestrogen tamoxifen and/or aromatase inhibitors. Expression of estrogen receptors- and - was most often detected in ER⁺PR⁺ tumors and most significantly decreased in these neoplasms after exemestane therapy. Immunocytochemical and radioligand assays showed that tamoxifen and anastrozole have little effect on the number of estrogen receptors- The number of progesterone receptors in tumors decreased by the end of anastrozole therapy. Estrogen receptors- were immunocytochemically revealed in 50% primary breast tumors. Anastrozole slightly decreased, while tamoxifen increased the incidence of these receptors. Interruption of signaling through estrogen receptors and suppression of estrogen biosynthesis had different effects on the receptor status of neoplasms and distribution of estrogen receptors- and -.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 11, pp. 559–562, November, 2004     

Effect of perftoran on macroglobulin content in the plasma and peritoneal exudate of rats with acute exudative inflammation (peritonitis)

The effect of blood substitute perftoran on the content of ₁- and ₂-macroglobulins in the plasma and exudate was studied in rats with acute exudative inflammation. After intravenous injection of perftoran macroglobulin content increased in the plasma, but remained unchanged in the peritoneal fluid.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 10, pp. 397–399, October, 2004     

Age-related differences in the response of blood stroke volume to stimulation of the sympathetic ganglion in rats with β-adrenoceptor blockade

Blood stroke volume in rats aging 21 and 56 days decreased during -adrenoceptor blockade with propranolol, but increased again by the 15th minute after treatment. Suprathreshold stimulation of the stellate ganglion decreased the stroke volume and increased the heart rate in control animals. Electrical stimulation after -adrenoceptor blockade was followed by a further decrease in stroke volume in young rats. In 100-day-old animals this parameter remained unchanged, while the cardiac output improved.Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 138, No. 10, pp. 393–396, October, 2004     

Responses in human pretibial muscles to sudden stretch and to nerve stimulation

Summary Electromyograms have been recorded from the human tibialis anterior muscle during voluntary contraction. The accessibility of the nerve to this muscle (common peroneal) has permitted a comparison of reflex responses to low threshold electrical stimulation of the nerve with those to stretch of the muscle itself. Nerve stimulation elicited a reflex at monosynaptic latency (V₁ at 28–29 ms) and a second response (V₂ at 50–52 ms). A tendon tap induced two responses (m₁ at 29 ms and M₂ at 50 ms). The responses to a ramp stretch were similar. The homology of V₁ with M₁, and of V₂ with M₂ is discussed. V₂ and M₂ probably correspond to the transcortical reflexes described from other muscles.Neither V₁ V₂, M₁ nor M₂ were influenced by anaesthesia of the foot. m₁ and M₂ were both reduced in amplitude by a selective -efferent block produced by local anaesthetic in the common peroneal nerve. It is concluded, that muscle spindles are the receptors predominantly responsible for M₂ (transcortical) responses.The amplitudes of M₁ and M₂, but not V₁ and V₂ were augmented by prior instruction to resist the stimulus. This is interpreted as evidence for voluntary modulation of -efferent activity at a constant force of contraction.Beit Memorial Research Fellow     

Mechanisms of Hyperpolarizing Effect of GABA on Resting Potential of the <Emphasis Type="Italic">Lumbricus Terrestris</Emphasis> Muscular Wall Somatic Cells

GABA, baclofen, isoguvacine increase, and cis-4-aminocrotonic acid does not modify resting membrane potential of muscle cells. Bicuculline, phaclofen, N-ethylmaleimide, chlorpromazine, verapamil, and removal of Ca²⁺ from bathing solution abolished the effect of baclofen, while U73122 and D609 were ineffective in this respect. The authors conclude that the Lumbricus terrestris muscle cells contain GABAergic structures similar to a- and b-receptors. Activation of GABA receptors induced Cl^- inward current and Ca²⁺ entry with subsequent activation of calmodulin-like proteins, which causes membrane hyperpolarization by increasing the effect of pumping potential on resting membrane potential.__________Translated from Byulleten Eksperimentalnoi Biologii i Meditsiny, Vol. 139, No. 2, pp. 219–222, February, 2005     

An α-mating-type-specific mutation causing specific defect in sexual agglutinability in the yeast Saccharomyces cerevisiae

We have identified a recessive -mating-type-specific gene agl causing agglutinability defect without significant effects on other sexual activities. a cells carrying agl showed sexual agglutination with cells but cells carrying agl showed sexual agglutination with neither cells nor a cells. cells carrying agl produced pheromone and responded to a pheromone just like wild cells. cells carrying agl showed a little decreased but significant mating ability when tested on solid media or membrane filter. The agl mutant is different from any -specific ste mutants found so far in many sexual activities. The agl gene is recessive, and unlinked to the mating type locus. Biological significance of the mating type agglutinability is discussed based on the results obtained with the mutant.     

Epithelial cell cultures from Botryllus schlosseri palleal buds: accomplishments and challenges

This study focuses on recent improvement in epithelial monolayer cultures originating from whole extirpated Botryllus schlosseri (Urochordata) buds. Buds (n = 2,000) were taken at different (A to D) blastogenic stages. We tested the suitability of 35 combinations of various substrates and media on attachment, cell spread, epithelial growth frequencies and on monolayer lifespans. Under favorable conditions, cultured buds at blastogenic stages B to D (but not stage A) started to attach to the substrates following a 3-day transient period that leads to formation of spheres and attached monolayers. Substrate type is important for the attachment and the development of monolayers. Under various culture conditions, some of stages B and C buds develop (3–20 days) one or more large (1 mm diameter) spheres. Stage D buds develop monolayers (up to 20% of buds) without going through a sphere phase. Neither spheres nor attached monolayers of epithelium were observed in stage A bud cultures. Spheres grew at a rate of 60 m in diameter per day using specific medium types and did not attach unless the appropriate substrate was present. When attached, epithelial monolayers expanded at a rate of 200 m in diameter per day, for 3–15 days, and subsequently detached and died. Sixteen types of media were tested. Medium and substrate combinations were found to determine epithelial lifespan. These results revealed significant improvements in the culture of epithelial monolayers from Botryllus palleal buds. However, an early senescence of the developed epithelial sheets (up to two weeks from onset of appearance) may indicate an internal ageing clock that should be taken into consideration in future approaches.     

Factors related to postmenopausal muscle performance: a cross-sectional population-based study

The aim of the present study was to investigate cross-sectionally the association of postmenopausal muscle strength with simple performance tests. A random sample of 1,166 naturally postmenopausal women (born 1932–1941) was selected from the Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) study cohort. Grip and quadriceps strength were measured with strain gauge dynamometers and reported in both absolute values (KPa and kg) and per kilogram of body mass (N cm^–2 kg^–1 and N kg^–1). In addition, two performance tests, ability to stand on one foot and ability to squat down to touch the floor were carried out. A five-category self-assessment of overall health (very good, good, moderate, bad, and very bad) was obtained by postal questionnaire. The women that were able to stand on one foot and able to squat down to touch the floor had greater grip and quadriceps strength than their counterparts (P<0.001 and P<0.03 in ANOVA, respectively). In addition, self-assessed health had a strong positive association with muscle strength in the grip and leg extensor muscles in ANOVA (P<0.001 between very good and moderate or poorer state of health) and regression model (P<0.001). Adjustment for age, duration of menopause, body mass, height, physical activity level, use of HRT, and number of diseases and medications did not change any of the main effects. Also, there were no differences in results between absolute measurement values and values reported per kilogram of body mass. According to the present study, a simple performance test may be useful in the prediction of postmenopausal muscle strength. Furthermore, self-assessed state of health is strongly associated with muscle strength in postmenopausal women.     

Activated charcoal is as effective as fuller's earth or bentonite in paraquat poisoning

Summary In vitro investigations have shown that the adsorption capacity of activated charcoal (Kohle-Compretten, Ultracarbon, E. Merck, Darmstadt, FRG) is just as high as that of Fuller's earth (Surrey powder, Laporte Industries Ltd., Luton, GB) or Bentonite BP W.B. (Steetley Minerals Ltd., Milton Keynes, GB). Fuller's earth (Fullererde) from another manufacturer has had very poor adsorption properties and is thus not suitable for the treatment of paraquat poisoning. Animal experiments have shown that the curative effect of activated charcoal given 0.5, 1, 2, and 3 h after ingestion of 200 and 300 mg paraquat/kg body weight is equally as good or even better than that of Fuller's earth or Bentonite BP W.B.. Activated charcoal is a substitute of equal value to these mineral soils.     

A new approach for evaluation of the in vitro haemolytic potential of a solution of a new medicine

In the process of developing an intravenously injectable drug, its haemolytic potential must be considered. There are no Regulatory Guidelines for this kind of test. Many authors have set up different models, attempting to obtain early information about the behaviour of test compounds when injected into the bloodstream.In the present work, an in vitro static model is presented, which takes into account the injection rate (R _inj.) of the drug, and the blood flow rate (Q _v) of the vein in which the drug must be injected. From the relationship between these two parameters, the C_max, expressed as mg/ml, can be calculated. This latter parameter allows us to calculate the drug concentration which, at any moment during injection, comes into contact with a known aliquot of new' blood passing through the injection site. Furthermore, a dynamic test has been developed, which simulates an injection into the blood flow using a tubing system and infusion pumps set for the same R _ini. and Q _v values used in static test. Two injectable drugs, Valium® and Lanoxin®, and a commonly used vehicle, propylene glycol, have been tested by both the methods. These compounds have also been tested with another in vitro method (Prieur et al. 1973), in which a volumetric blood-to-test solution ratio of 1:1 is adopted for every drug tested, with neither R _inj. nor Q _v being taken into account. Results of the haemolytic potential obtained with the three tests have been compared.A good correlation has been observed between the static and the dynamic tests, whereas Prieur's model, which uses a drug-to-blood ratio which is far higher than in vivo, has been shown to give false positive results.It is concluded that a test for the evaluation of the haemolytic potential of drugs must take into account the pharmacodynamic characteristics of the formulation intended to be injected, and at least the blood flow rate. The proposed static test has been demonstrated to be an easy and reliable method of obtaining a true picture of the in vivo situation.     

Recognition by peptide mapping of three different structural groups of outer membrane protein YOP-1 of Yersinia enterocolitica and Yersinia pseudotuberculosis

The structural relation of YOP-1 of european and american Yersinia enterocolitica serotypes O3, O9, O5, 27, and O8 and O20, respectively, and Y. pseudotuberculosis serotypes I, II, and III was compared by sodium dodecyl sulfate polyacrylamide gel electrophoresis and peptide mapping using Staphylococcus aureus protease V8. Apparent molecular weights of YOP-1 ranged from 206,000 (O3) to approx. 180,000 (O8). According to their respective peptide maps YOP-1 of the european and american Y. enterocolitica serotypes and Y. pseudotuberculosis serotypes could be assigned to three different groups. Evaluation of several isolates of Y. enterocolitica serotypes O3, O9, and O8 by peptide mapping indicated that YOP-1 is conserved within a serotype. However, one serotype O8 isolate differed from the consensus peptide pattern of the other serotype O8 and O20 isolates. The similarity of the peptide patterns of Yersinia serotypes which predominate in certain geographical locations, i. e., european and american Y. enterocolitica serotypes, suggest common evolution of YOP-1 of these serotypes independent of the evolution of the other serotypes.     

The contractile behaviour of EGTA- and detergent-treated heart muscle

Summary Tension responses of rat ventricular trabeculae subjected to successive treatment with EGTA and Triton X-100 are described in order to investigate the effects of chemical skinning techniques. In some preparations the alkaloid saponin was also used before Triton. Ultrastructural evidence is cited that the EGTA-treatment fails to render cells hyperpermeable, i.e. freely permeable to small ions, whereas both saponin and Triton do so. In this paper we show that contractile responses like those described previously for the EGTA-treated tissue can be obtained. However, more detailed examination shows that such behaviour is quantitatively distinct from that of conventionally skinned fibres in a way that is incompatible with the notion of hyperpermeability. The Ca-sensitivity after treatment with either EGTA, saponin or Triton is identical in our hands. However, this is not explained by free access of Ca (and EGTA) to the intracellular space in the EGTA-treated preparation: contractures develop with very different time courses, being fastest after Triton and only marginally slower when first exposed to saponin but a factor of five times slower after EGTA-treatment alone. This applies to contractures evoked direct from Ca²⁺ concentration 10^–9 m to the test Ca²⁺ concentration at constant total buffer concentration.EGTA-treated fibres develop tension when ATP or creatine phosphate (CrP) are removed from the bath. However, responses to ADP and to CrP changes persist with millimolar levels of ATP present, quite unlike the Triton-skinned muscle. Exposure to each of a variety of solutions for 24h produce preparations showing similar behaviour: whatever the explanation for the EGTA-skinning phenomenon it is not dependent upon low bathing Ca²⁺ concentration. On the basis of the functional characteristics described here, and the structural results cited, we conclude that the cell membrane continues to function as a selective permeability barrier after EGTA-treatment: this treatment does not produce a model of a selectively skinned cardiac cell.     

Enterococcus faecium in hospitals

Most of the characteristics that have ensured the success of enterococci as nosocomial pathogens were described early in this century.Enterococcus faecium andEnterococcus faecalis, the enterococci most frequently isolated from clinical material, differ fundamentally. The intrinsic antimicrobial resistance ofEnterococcus faecium, supplemented by acquired resistance mechanisms, can generate a glycopeptide-multiply-resistant nosocomial pathogen that survives on hands and in the environment, and has the potential for intra-hospital and inter-hospital spread. The use of terms such as an enterococcus, faecal streptococci and group D streptococci have hindered, and still hinder, our understanding of a species rapidly emerging as the most problematic of nosocomial pathogens.