Transfer of autoimmune encephalomyelitis with T lymphocytes in strain 13 guinea pigs

Experimental autoimmune encephalomyelitis (EAE) and/or tuberculin sensitivity were transferred to histocompatible recipients with myelin basic protein-stimulated and/or PPD stimulated guinea pig lymph node T cells previously separated by depletion of B cells ("panning") on rabbit anti-guinea pig Ig antibody-coated Petri plates. The depletion was augmented by complement-mediated lysis using mouse anti-guinea pig B-cell monoclonal antibody (31D2), rabbit anti-mouse Ig, and rabbit complement. B cells did not transfer EAE nor provide protection against active immunization with guinea pig spinal cord antigen.     

Cellular receptors for lymphotoxin: correlation of binding and cytotoxicity in sensitive and resistant target cells.

The binding of radioactively labeled lymphotoxin (LT) to both lymphotoxin-sensitive and -resistant cell clones was examined. The sensitive clone had a low- capacity, high-affinity ("specific") binding component, the curve of which closely followed the cytotoxicity curve of the lymphocyte mediator. The capacity of this binding component was calculated to be about 600 molecules of LT/cell. In addition, there was a low-affinity, high-capacity ("nonspecific") binding component. In striking contrast, the high-affinity, low-capacity ("specific") component was absent or greatly diminished from the resistant clone, whereas the low-affinity, high-capacity ("nonspecific") component was present at a similar level as in the sensitive cells.These binding characteristics closely resemble those observed by us and other investigators working with a variety of steroid hormones in steroid-sensitive and- resistant cell lines.     

Chronogenetic control or the continuity of morphological organization during postnatal ontogenesis of man

Chronological peculiarities of genetic regulation of growth processes in morphological structures of postcranial skeleton ("body") and cranium ("head") were studied at different phases of peripubertal stage of boys ontogenesis. The component partitioning of the phenotype variance of individual scores of the structures considered revealed relative autonomy of chronogenetic systems controlling morphogenesis in the "body" and the "head". Succession of morphological organization is ensured by the stable level of correlation between morphological structures analysed. Raise in correlation is registered at the "critical" phase (13-14 years) which is connected with the "switching on" genetic programme of growth processes control in the adolescent period of human postnatal ontogenesis.     

Transport proteins of Plasmodium falciparum: defining the limits of metabolism

In this review we give an account of transport processes occurring at the membrane interface that separates the asexual stage of Plasmodium falciparum from its host, the infected erythrocyte, and also describe proteins whose activities may be important at this location. We explain the potential clinical value of such studies in the light of the current spread of parasite resistance to conventional antimalarial strategies. We discuss the uptake of substrates critical to the survival of the intracellular malaria parasite, and also the parasite's homeostatic and disposal mechanisms. The use of the Xenopus laevis expression system in the characterisation of a hexose transporter ("PfHT1") and a Ca(2+) ATPase ("PfATP4") of the parasite plasma membrane are described in detail.     

Marked Alteration at Midblastula Transition in the Effect of Lithium on Formation of the Larval Body Pattern of Xenopus laevis

Embryos of Xenopus laevis were exposed to 0.4 M LiCl for 5 min at various stages of development. The effect of lithium on the larval body pattern could be detected from the 2-cell to the late gastrula stage, but changed from reduction of posterior structures ("anteriorization") to reduction of anterior structures ("posteriorization") just after the 12th cleavage, the time of midblastula transition (MBT). Temporal coincidence of MBT with alteration of the effect of lithium was observed even with embryos derived from half-egg fragment, in which MBT occurs just after the 11th cleavage. These results suggest the existence of a mechanism for formation of the basic plan of the larval body whose function changes at MBT. Combinations of the pre- and post-MBT exposures to lithium induced marked posteriorization in most larvae, indicating that the basic plan is not irreversibly determined until MBT, but is fixed during post-MBT stages.     

Selection for nonbuoyant morphological mutants of Caulobacter crescentus.

Morphological mutants of Caulobacter crescentus were isolated by selecting for cells that did not possess normal, buoyancy-conferring stalks. The most prevalent phenotype enriched by the selection was structurally deficient stalks (designated "Cds"), observable as crumpled or flattened stalks. The second phenotype ("Abs") was observed as spontaneous shedding of normal-appearing stalks. Third, one mutant ("Ecs") was isolated that sheds not only stalks, but also miniature stalked and nonstalked cells.     

Dissociable influences of auditory object vs. spatial attention on visual system oscillatory activity

Given that both auditory and visual systems have anatomically separate object identification ("what") and spatial ("where") pathways, it is of interest whether attention-driven cross-sensory modulations occur separately within these feature domains. Here, we investigated how auditory "what" vs. "where" attention tasks modulate activity in visual pathways using cortically constrained source estimates of magnetoencephalograpic (MEG) oscillatory activity. In the absence of visual stimuli or tasks, subjects were presented with a sequence of auditory-stimulus pairs and instructed to selectively attend to phonetic ("what") vs. spatial ("where") aspects of these sounds, or to listen passively. To investigate sustained modulatory effects, oscillatory power was estimated from time periods between sound-pair presentations. In comparison to attention to sound locations, phonetic auditory attention was associated with stronger alpha (7-13 Hz) power in several visual areas (primary visual cortex; lingual, fusiform, and inferior temporal gyri, lateral occipital cortex), as well as in higher-order visual/multisensory areas including lateral/medial parietal and retrosplenial cortices. Region-of-interest (ROI) analyses of dynamic changes, from which the sustained effects had been removed, suggested further power increases during Attend Phoneme vs. Location centered at the alpha range 400-600 ms after the onset of second sound of each stimulus pair. These results suggest distinct modulations of visual system oscillatory activity during auditory attention to sound object identity ("what") vs. sound location ("where"). The alpha modulations could be interpreted to reflect enhanced crossmodal inhibition of feature-specific visual pathways and adjacent audiovisual association areas during "what" vs. "where" auditory attention.     

Activation of ryanodine receptors by flash photolysis of caged Ca2+.

Flash photolysis of DM-nitrophen generates an extremely large [Ca2+] transient ("Ca2+ spike") at the start of each Ca2+ "step." The Ca2+ spike greatly increases the speed of activation of the ryanodine receptor channel ("supercharging") and could be responsible for apparent channel adaptation.     

Stability of a melittin pore in a lipid bilayer: a molecular dynamics study

We have investigated the configuration and the stability of a single membrane pore bound by four melittin molecules and embedded in a fully hydrated bilayer lipid membrane. We used molecular dynamics simulations up to 5.8 ns. It is found that the initial tetrameric configuration decays with increasing time into a stable trimer and one monomer. This continuous transformation is accompanied by a lateral expansion of the aqueous pore exhibiting a final size comparable to experimental findings. The expansion-induced formation of an interface between the pore-lining acyl chains of the lipids and the pore water ("hydrophobic pore") is transformed into an energetically more favorable toroidal pore structure where some lipid heads are translocated from the rim to the central part of the interface ("hydrophilic pore"). The expansion of the pore is supported by the electrostatic repulsion among the alpha-helices. It is hypothesized that pore growth, and hence cell lysis, is induced by a melittin-mediated line tension of the pore.     

Costs of parturition and rearing in female sika deer (Cervus nippon)

The costs of parturition and lactation of female sika deer on Kinkazan Island (9.6 km(2) in size), northern Japan, which live at a high density (about 50 deer/km(2)), were evaluated by comparison of body weights of 481 females measured during a 15 year study (1993-2008). Weight data were chosen from only females that did not give birth in the preceding year. The mean body weight of females that did not give birth ("yelds") was significantly lower (P < 0.001) than that of females who gave birth ("milks"); yelds' body weight was 93.1% and 83.5% that of milks in the preceding and parturition years, respectively. The yelds increased in body weight by the following March by 8.2% (P < 0.001), whereas milks did not. Among the milks, those whose fawns survived until the following May ("rearing milks") lost body weight by 14.9% (P < 0.001). Milks who lost fawns within a week after birth ("early fawn-less milks") did not lose body weight (P = 0.583), while those whose fawns died after the first autumn but died before May ("late fawn-less milks") lost body weight by 19.9% (P < 0.001). These results indicate that sika deer females do not enter estrus unless they are heavy enough, and that both parturition and rearing are costly for sika deer mothers living in high-density conditions.     

Studies on nucleoli in rosetting T and B lymphocytes of the human peripheral blood

The incidence of various nucleolar types was studied in human rosetting lymphocytes to provide an information on nucleolar types present in T and B lymphocytes of the peripheral blood. The results clearly demonstrate that both T and B lymphocytes of the peripheral blood mostly contain ring shaped nucleoli ("resting nucleoli") and less frequently other nucleolar types such as nucleoli with nucleolonemata or compact nucleoli ("active nucleoli") and micronucleoli ("inactive nucleoli"). Since all known nucleolar types and particularly micronucleoli may be observed in both T and B lymphocytes, nucleoli in these cells cannot indicate the type or origin of these cells but simply the state of the nucleolar RNA synthesis.     

Structure of peptostreptococcal protein L and identification of a repeated immunoglobulin light chain-binding domain.

The gene for protein L, an immunoglobulin (Ig) light chain-binding protein expressed by some strains of the anaerobic bacterial species Peptostreptococcus magnus, was cloned and sequenced. The gene translates into a protein of 719 amino acid residues. Following a signal sequence of 18 amino acids and a NH2-terminal region ("A") of 79 residues, the molecule contains five homologous "B" repeats of 72-76 amino acids each. Further, toward the COOH terminus, two additional repeats ("C") were found. These are not related to the "B" repeats, but are highly homologous to each other. After the C repeats (52 amino acids each), a hydrophilic, proline-rich putative cell wall-spanning region ("W") was found, followed at the COOH-terminal end by a hydrophobic membrane anchor ("M"). Fragments of the gene were expressed, and the corresponding peptides were analyzed for Ig-binding activity. The B repeats were found to be responsible for the interaction with Ig light chains. An Escherichia coli high level expression system was adapted for the production of large amounts of two Ig-binding protein L fragments comprising one and four B repeats, respectively.     

Salt-induced refolding of myoglobin at acidic pH: molecular properties of a partly folded intermediate.

The molecular properties of the salt-induced partly folded acidic state of apomyoglobin as well as myoglobin were investigated by fluorescence and circular dichroism of the extrinsic fluorophore 1,8-anilinonaphthalenesulfonate. The occurrence of a fluctuating tertiary structure ("molten globule") at acidic pH in the presence of salt was suggested by the disappearance of the dichroic activity of the fluorophore bound to the partly folded protein. Moreover, the structure of the intermediate is not influenced by the presence of heme, thus suggesting that heme is not crucial in the early stage of myoglobin folding.     

Development of Bdellophage VL-1 in Parasitic and Saprophytic Bdellovibrios

Ultrastructure was correlated with growth kinetics of bdellophage VL-1 infecting host-dependent ("parasitic") Bdellovibrio bacteriovorus 109J in its Escherichia coli B host (the three-membered system), as well as in the host-independent ("saprophytic") derivative of the Bdellovibrio. Electron microscope observations showed the arrested growth of the phage-infected bdellovibrios, polar localization of the phage progeny, and stages in their release. Present evidence indicates that bdellophage DNA is derived from both the Bdellovibrio and its host cell.     

Microbiological examination of sebeel water.

Water samples from clay storage jugs ("zeers") located in homes and at public watering stands ("sebeels") at streets, mosques, and schools were examined. Coliforms, fecal coliforms, and fecal streptococci were detected in 100, 69, 88, and 91.56% of the samples, respectively. The general microbiology of the water and some factors affecting microbial load were studied. The predominant bacterial genera of sebeel water were found to be Staphylococcus. Aerococcus, Micrococcus, Streptococcus, Bacillus, Listeria, Lactobacillus, and Arthrobacter. A simple modification of zeer construction was suggested to help improve sanitation.     

Environment- and gene-dependent human ontogenesis, sociogenesis and phylogenesis (eco-geno-onto-socio-phylogenesis)

Prevention of environment- and gene-dependent, teratogenic malfunctions ("Functional Teratogenesis")-- caused by abnormal hormone, neurotransmitter and cytokine concentrations during organization of the neuro-endocrine-immune system (NEIS) should be considered as a global challenge of outstanding relevance. By optimizing the natural and social environment and correcting in time abnormal concentrations of hormones, neurotransmitters and cytokines during the critical perinatal (pre- and early postnatal) organization period of the NEIS ("Neuro-Endocrine-Immune Prophylaxis") human ontogenesis and sociogenesis can be decisively improved ("Primary Prevention of Maldevelopments of Human Beings and their Societies"). Finally, phylogenesis is dependent on incessant sequencies of ontogenesis and sociogenesis ("Onto-Socio-Phylogenesis").     

Morphological aspects of lymphocyte-macrophage interactions in human tumoral effusions "in vivo" and "in vitro"

"In vivo" and "in vitro" morphological analysis of associations of cells ("rosettes") involved in immune response in human tumoral effusions revealed the existence of cell interactions either by simple membrane apposition between the cell projections or by gap-like junctions between two adjacent cells; endocytotic phenomena were also observed. The giant fibroblastic cells seen "in vitro" ("myofibronoblasts") reacting positively to anti-human macrophage Mabs, might be the cells presenting antigen to lymphocytes.     

Continuous production of human leukocyte interferon withEscherichia coli and continuous cell lysis in a two stage chemostat

Summary The continuous production and extrac-tion of human leukocyte interferon (type α2) in a two stage chemostat is described. Interferon con-tainingEscherichia coli cells were produced in the first stage and transferred to the second stage, where the cells were lysed continuously by the ad-dition of ampicillin. The medium used was based on corn steep liquor. Highest interferon titres and the best extraction efficiencies were achieved when running the first and second stages at dilution rates of 0.3 h⁻¹ and 0.1 h⁻¹, and at temperatures of 30° C and 25 °C, respectively. In order to prevent loss of interferon in the second stage, oxygen limitation had to be avoided. For optimal cell lysis there should be excess glucose in the second stage and the ampicillin concentration should be maintained above 100 mg 1⁻¹.     

MHC restriction of the anti-allotypic response of T-lymphocytes in vitro

In vitro MHC restriction of antigen-specific T-cell proliferation to Igk-Ib allotype of Igk chain has been studied in inbred August rats, using polyclonal and monoclonal antibodies to RT-1 molecules. Igk-1b-specific proliferation of immune T cells was completely abrogated by alloantiserum specific for RT-1c (August) molecules. Monoclonal antibodies (MAb) to RT-1B ("1-A-like") molecules inhibited markedly the response (about 70-80% inhibition), while anti-RT-ID ("I-E-like") MAb caused but weak inhibition (about 25%). Thus, the data obtained demonstrate RT-1Bc molecule as a main restriction element of Igk-1b-specific T-cell response.