Persistence of bacterial pathogens as a physiological phenomenon

The complex ecosystem of humans and microbes has been presented as an associative symbiosis based on a mutual support of symbionts with different consequences for them. Conditions for the persistence of bacteria have been defined: their resistance to environmental factors, antagonism in biocenosis, and stability to withstand host defense mechanisms. The key role of bacterial peptidoglycan has been defined for their survival in an infected organism, and the classification for persistent mechanisms of pathogens has been given. The group of bacterial secreted protease providing microbial resistance to defense factors of the organism has been described. Host colonizing resistance has been presented as a physiological regulatory system controlling bacterial penetration into an organism. Regulatory mechanisms for bacterial persistence have been discussed.     

Linked Cross Sectional Schemes for Estimating Growth of Children

For estimation of growth, the efficiency of linked cross sectional scheme has been compared with pure longitudinal and cross sectional schemes. The relevant estimation theory has been developed and the expressions for the optimum estimators alongwith their variances have been derived. It has been observed that for estimation of growth, the linked cross-sectional scheme has been observed to be less efficient as compared to pure longitudinal scheme but more efficient than pure cross-sectional scheme.     

Sampling Schemes for Studying Growth of Children

Efficiency of linked cross-sectional scheme has been compared with pure longitudinal schemes for generalised estimation of norm relaxing the condition of constancy of variances. The relevant theory of estimation has been developed and the expression for the optimum estimators alongwith their variances have been derived. The percentage gain in efficiency has been calculated. It has been observed that for higher values of Q, percentage gain in efficiency of proposed scheme over cross-sectional is very high.     

Photomyoclonic seizures in the baboon, Papio papio.

The inborn seizure response of Papio papio to intermittent light stimulation has been reviewed as a model of human epilepsy. The electrographic and clinical features have been described and useful methodology has been outlined. A diurnal cyclicity in seizure responsiveness has been described with greatest seizure severity at 8 AM in parallel with a rise in urinary output of cortisol. Hormonal influences on the seizure response have been described for ethinyl estradiol, thyroxin, and triiodothyronine. Evidence regarding neurotransmitter involvement has been reviewed. Data regarding use of the animal for anticonvulsant testing in single and chronic doses has been discussed. Particular advantages of the model for study of age-related drug effects and the assessment of the effects of chronically administered anticonvulsant agents on learning and memory have been described.     

Elaboration of PCR MP diagnostic kit for genetic typing of bacterial strains

The rules of diagnostic kit elaboration for genetic typing of microorganisms, designed for epidemiological studies, have been shown in this paper. PCR MP method has been used for diagnostic kit elaboration. Well defined epidemiologically Enterococcus faecium strains have been applied as a research model. The optimisation of the method has been carried out using different amount of reagents and time of the particular stages. Critical parameters, which have significant influence on the quality of obtained results, have been assigned. Optimalised procedure, named PCR MP unique, has been validated for genetic typing of different species of microorganisms and its potential application for routine epidemiological studies. The PCR MP method has been successfully used for elaboration of diagnostic PCR MP unique-KIT, which allows intra-species differentiation of bacterial strains. The PCR MP unique-KIT enables fast, easy and cheap analysis of strains, using elementary laboratory equipment--gradient thermocycler.     

Oligonucleotide derivatives in the nucleic acid hybridization analysis. II. Isothermal signal amplification in process of DNA analysis by minisequencing

The isothermal amplification of reporter signal via limited probe extension (minisequencing) upon hybridization of nucleic acids has been studied. The intensity of reporter signal has been shown to increase due to enzymatic labeling of multiple probes upon consecutive hybridization with one DNA template both in homophase and heterophase assays using various kinds of detection signal: radioisotope label, fluorescent label, and enzyme-linked assay. The kinetic scheme of the process has been proposed and kinetic parameters for each step have been determined. The signal intensity has been shown to correlate with physicochemical characteristics of both complexes: probe/DNA and product/DNA. The maximum intensity has been observed at minimal difference between the thermodynamic stability of these complexes, provided the reaction temperature has been adjusted near their melting temperature values; rising or lowering the reaction temperature reduces the amount of reporting product. The signal intensity has been shown to decrease significantly upon hybridization with the DNA template containing single-nucleotide mismatches. Limited probe extension assay is useful not only for detection of DNA template but also for its quantitative characterization.     

Ancient lakes as evolutionary reservoirs: evidence from the thalassoid gastropods of Lake Tanganyika

Ancient lakes are often collectively viewed as evolutionary hot spots of diversification. East Africa's Lake Tanganyika has long been the subject of scientific interest owing to dramatic levels of endemism in species as diverse as cichlid fishes, paludomid gastropods, decapod and ostracod crustaceans and poriferans. It is the largest and deepest of the African rift lakes, and its endemic fauna has been presented with a stable inland environment for over 10 Myr, offering unique opportunities for within-lake diversification. Although astonishing diversification has been documented in the endemic cichlid fauna of the lake, similar patterns of rapid diversification have long been assumed for other groups. In contrast to this hypothesis of rapid speciation, we show here that there has been no acceleration in the rate of speciation in the thalassoid gastropods of the lake following lake colonization. While limited within-lake speciation has occurred, the dramatic conchological diversity of gastropods presently found within the lake has evolved from at least four major lineages that pre-date its formation by as much as 40 Myr. At the same time, a widespread group of African gastropods appears to have evolved from taxa presently found in the lake. While Lake Tanganyika has been a cradle of speciation for cichlid fishes, it has also been an important evolutionary reservoir of gastropod lineages that have been extirpated outside the basin.     

Morphological measurements on filamentous microorganisms by fully automatic image analysis

Characterization of mycelial morphology is important for physiological and engineering studies of filamentous fermentations, and in the design and operation of such fermentations. Image analysis has been developed as a method for this characterization, and has been shown to be faster and generally more accurate than previous methods. A fully automatic system has been developed, in which speed is gained, but with loss of accuracy in some cases. The method has been tested on Streptomyces clavuligerus and Penicillium chrysogenum P1 batch fermentations. It has also been tested on a fed-batch Penicillium chrysogenum P2 fermentation, in which the medium contained solid ingredients. Fully automatic image analysis for morphological characterization of filamentous microorganisms is an important development which will make practical many engineering and physiological studies of such fermentations that have so far not been completely satisfactory.     

ISOLATION AND PROPERTIES OF LIVER CELL NUCLEOLI

1. The significance of the term nucleolus has been discussed. 2. A detailed method for the isolation of nucleoli from already isolated rat or cat liver nuclei has been presented. 3. The presence of DNA in isolated liver cell nucleoli has been indicated by histochemical methods. 4. The percentages of DNA and RNA in the isolated nucleoli have been determined by chemical analysis. 5. The specific activities of aldolase, arginase, and catalase have been determined for two subnuclear fractions and for the isolated nucleoli of rat and cat liver, and the relative amounts of these enzymes in the same subnuclear fractions and nucleoli of rat liver have been measured. 6. The significance of the above findings has been discussed and consideration has been given to what types of isolated nuclei might best serve as starting material for the isolation of nucleoli. 7. A new hypothesis has been presented that nucleoli of the liver cell type may function primarily in furnishing (directly or indirectly) templates for the synthesis of the particular enzymes that must govern the chemistry of mitosis.     

Cytosolic and non-cytosolic carbonic anhydrase enzymes from bovine leukocytes.

In this study, carbonic anhydrase (CA) enzyme has been purified and separately characterized according to bound form in 4 steps as outer peripheral, cytosolic, inner peripheral, and integral from bovine leukocyte. Affinity chromatography has also been used for purification of the enzyme in four steps. CA has been found for each step. Measurment of enzyme activity has been done by CO2 hydratase activity and esterase activity methods. Optimum pH and optimum temperature have been defined for each step of purified enzyme. The behaviors of CA with specific inhibitors, such as KSCN and NaN3 have been investigated. In each step, molecular weight and purity have been determined by gel filtration and SDS-PAGE electrophoresis. In addition, enzyme K(M) and Vmax values have been determined with the method of Lineweaver-Burk.     

NASDA aquatic animal experiment facilities for Space Shuttle.

National Space Development Agency of Japan (NASDA) has been developed aquatic animal experiment facilities for space experiments using NASA Space Shuttle. Vestibular Function Experiment Unit (VFEU) has been firstly designed and developed for Spacelab-J mission (STS-47), and 8 days space experiment with carp has been performed. Following, the VFEU, Aquatic Animal Experiment Unit (AAEU) has been developed to accommodate small aquatic animals second International Microgravity Laboratory mission (IML-2, STS-65). Four kinds of space experiments with goldfish, medaka, newt, and newt eggs have been performed for 15 days mission duration. Then, VFEU has been improved to accommodate marine fish under low temperature condition for Neurolab (STS-90) and STS-95 missions. 17 days (STS-90) and 9 days (STS-95) experiments with oyster toadfish have been performed by using the VFEU. This report summarizes the outline of these aquatic animal experiment facilities.     

Mapping of phase response properties of monopolar ECG voltages

In the present investigation an attempt has been made to study the phase response properties of monopolar chest lead ECG voltages. Using a generator model of the heart an equivalent circuit of ECG network has been developed. The equivalent impedance between WCT and probe electrode has been determined by reduction techniques. From this equivalent impedance the phasor characteristics of monopolar ECG voltages have been analysed for change in probe electrode locations. The source of the generated voltage, i.e., the heart, will develop a different voltage for its different condition. There will also be a change in impedances. Thus for the normal subject the distribution of the phasor of the ECG voltages will be different from that of the abnormal one. A software tool has been developed to evaluate the relative phase response of ECG voltages. The data acquisition of monopolar ECG records of chest leads V1 to V6 from chart recorder has been done with the help of AutoCAD application package. The harmonic constituents of ECG voltages have been evaluated at each harmonic plane and the phase characteristics have been studied in polar coordinate for normal subjects as well as for a typical case. An interesting result has been observed in typical cases which are indicated in the paper.     

Restriction endonucleases: the detection of new producer strains and the isolation of enzyme preparations]

The method for analysis of microorganisms for the presence of the modification-restriction systems has been developed. The method has permitted to detect more than 10 new producing strains of restrictases including microorganisms of Rhizobium genus. Some of them are promising for practical use. It has been shown that using selection of clones the strain productivity can be increased. The purification process for the majority of restrictases has been proposed. Some physical and catalytic properties of new enzymes have been studied.     

The Slide-Sealing Compound "Glyceel"

"Glyceel" has been considered for many years to be the best sealant for whole mounts of soil, plant-parasitic, freshwater, and marine nematodes. However, "Glyceel" has not been available since the mid 1980s when its production was halted. Currently available substitutes are inadequate. The original formula for "Glyceel" has been found in the literature and is given here with a method of preparation. "Glyceel" prepared in this way by the author has been used and appears to function well.     

Sugar beet (Beta vulgaris L.) morphogenesis in vitro: Effects of phytohormone type and concentration in the culture medium, type of explants, and plant genotype on shoot regeneration frequency

In vitro regeneration techniques have been optimized for seven strains and cultivars of sugar beet (Beta vulgaris L.) bred in Russia. The frequency of shoot regeneration from somatic cells and tissues of sugar beet varies from 10 to 97% depending on the explant type, culture-medium composition, and genotype. The in vitro regeneration potential has been estimated in plants with different genotypes. The effect of medium composition (phytohormones and carbohydrates) on the frequency of the formation of a morphogenic callus competent for plant regeneration has been determined. The effect of the types and concentrations of various cytokines (zeatin, kinetin, and 6-benzylaminopurine) on direct shoot regeneration from cotyledon nodes has been estimated. The culture-medium composition has been optimized for direct shoot regeneration from petioles. The effects of different concentrations of abscisic acid on the frequency of shoot regeneration from a morphogenic callus has been studied. Micropropagation has been used to obtain petiole explants and reproduce the shoots obtained by direct regeneration from cotyledonnodes, petioles, and calluses. Improved shoot-regeneration methods can be used for both agrobacterial and bioballistic genetic transformation of the sugar beet genotypes studied.     

Melanocyte-directed enzyme prodrug therapy (MDEPT): development of a targeted treatment for malignant melanoma.

A novel prodrug rationally designed to function as a tyrosinase substrate has been synthesised to allow targeted treatment of malignant melanoma. This agent has been evaluated for tyrosinase-mediated drug release, and has been shown to act in the desired manner. Furthermore, differential cytotoxicity has been demonstrated in cell lines which express tyrosinase and those which do not.     

5'-methylthioadenosine phosphorylase from the human prostate. 1. Purification and partial characterization]

5'-Methylthioadenosine phosphorylase has been purified approximately 340-fold in 20% yield from human prostate: the use of affinity chromatography by Sepharose-Hg has been found particularly advantageous. The enzyme has been partially characterized and an apparent Km of 2.5 x 10(-5) M has been calculated for 5'-methylthioadenosine. The reaction is activated by thiols and shows an absolute requirement for phosphate ions.     

A novel property of DNA - as a bioflotation reagent in mineral processing

Environmental concerns regarding the use of certain chemicals in the froth flotation of minerals have led investigators to explore biological entities as potential substitutes for the reagents in vogue. Despite the fact that several microorganisms have been used for the separation of a variety of mineral systems, a detailed characterization of the biochemical molecules involved therein has not been reported so far. In this investigation, the selective flotation of sphalerite from a sphalerite-galena mineral mixture has been achieved using the cellular components of Bacillus species. The key constituent primarily responsible for the flotation of sphalerite has been identified as DNA, which functions as a bio-collector. Furthermore, using reconstitution studies, the obligatory need for the presence of non-DNA components as bio-depressants for galena has been demonstrated. A probable model involving these entities in the selective flotation of sphalerite from the mineral mixture has been discussed.     

Molecular-genetic organization of plasmid R89S of the incompatibility group Q

A new IncQ plasmid R89S has been analysed by molecular-genetic methods. A restriction map of this plasmid has been constructed and regions of homology with the plasmid RSF1010 have been identified. A genetic map of the plasmid R89S has been prepared based on the deletion and insertion plasmid derivatives. The phenotypic analysis of the derivatives has identified the location of genes coding for replication, incompatibility, mobilization for genetic transfer and resistance to streptomycin in the genome of R89S.