Possible mechanisms underlying effects of N-uronoyl derivatives of amino acids on electrical activity in snail neurons

Using intracellular recording, we studied the effects of N-uronoyl derivatives of an amino acid and peptides (1,2:3,4-di-O-isopropylidene-αa-D-galactopyranuronoyl)-β-alanine (DAGU-Ala), DAGU-glycyl-glycine (DAGU-Gly-Gly), DAGU-glycyl-D,L-glutamic acid (DAGU-Gly-Glu), as well as of 1,2:3,4-di-O-isopropylidene-αa-D-galactopyranosyluronic acid (DAGU itself), β-alanine (β-Ala), D,L-glutamic acid (D,L-Glu), and glycyl-glycine (Gly-Gly), which were added to the extracellular milieu, on the electrical activity of PPa1 and PPa2 neurons and unidentified neurons of Helix albescens Rossm. DAGU-Gly-Gly applied in concentrations of 10⁻⁴ to 10⁻² M hyperpolarized the membrane in a dose-dependent manner and decreased insignificantly the amplitude of action potentials (APs). Applications of DAGU-Ala, β-Ala, DAGU-Gly-Glu, D,L-Glu, and Gly-Gly in the same doses resulted in a shift of the membrane potential toward depolarization and in a drop in the amplitude of APs. Measurements of the first AP derivatives showed that all the above-mentioned substances suppressed in a concentration-dependent manner both inward and outward transmembrane ion currents. In this case, DAGU suppressed both inward and outward currents, while DAGU-Ala, β-Ala, DAGU-Glu, D,L-Glu, and Gly-Gly inhibited predominantly the outward potassium ion current; DAGU-Gly-Gly inhibited inward sodium and potassium ion currents. Results of a comparative analysis of the neurotropic action of the tested amino acids and their N-uronoyl derivatives showed that modification of the molecules of neurotransmitter amino acids leads to a decrease in their neurotoxicity and to an increase in their membranotropic properties. Neirofiziologiya/Neurophysiology, Vol. 38, Nos. 5/6, pp. 416–425, September–December, 2006.     

Two new motile phototrophic consortia: “Chlorochromatium lunatum” and “Pelochromatium selenoides”

Two new phototrophic consortia, “Chlorochromatium lunatum” and “Pelochromatium selenoides”, were observed and collected in the hypolimnion of several dimictic lakes in Wisconsin and Michigan (USA). The two consortia had the same morphology but different pigment composition. The cells of the photosynthetic components of the consortia were half-moon-shaped. This morphology was used to differentiate them from the previously described motile phototrophic consortia “Chlorochromatium aggregatum” and “Pelochromatium roseum”. These phototrophic cells did not resemble any described unicellular green sulfur bacteria. The predominant pigments detected were bacteriochlorophyll d and chlorobactene for the green-colored “Clc. lunatum”, and bacteriochlorophyll e and isorenieratene for the brown-colored “Plc. selenoides”. Their pigment compositions and the presence of chlorosomes attached to the inner face of the cytoplasmic membrane in both kinds of photosynthetic cells confirmed this new half-moon-shaped morphotype as a green sulfur bacterium. Both consortia were found thriving in lakes with low concentrations of sulfide (< 60 μM), below the layers of “Clc. aggregatum” and “Plc. roseum”. The green consortia were observed in lakes where the oxic-anoxic interface was located at shallow depths (2–7 m), while the brown consortia were found at greater depths (8–16 m). The two newly described consortia were never detected together at the same depth in any lake. Received: 30 April 1997 / Accepted: 17 January 1998     

Neuropharmacological profile of a high-affinity ligand of 5-HT1A receptors, 4-phenyl-1-[4-(2-naphtalimido)butyl]-piperazine

The neuropharmacological profile of 4-phenyl-1-[4-(2-naphtalimido)butyl]-piperazine (PNBP), a compound that possesses a high affinity for the serotonin receptors of 1A-type (5-HT_1A) and lacks an anxiolytic action, has been studied. Intracerebral administration of PNBP to rats through implanted cannulae into the hippocampal region resulted in no substantial behavioral changes during “open field” and “conflict situation” tests, as compared with those of control animals. At the same time, the behavioral effects of intraperitoneal administration of 10 mg/kg buspirone were completely abolished if buspirone had been jointly administered with 10 mg/kg PNBP. Moreover, combined application of 0.3 mg/kg PNBP and 0.3 mg/kg 8-OH-DPAT, an agonist of 5-HT_1A receptors, almost completely abolished the components of “serotonin syndrome” (prone position and stamping of the forepaws) in animals under study. These findings allowed us to conclude that PNBP has the properties of a competitive antagonist of buspirone and 8-OH-DPAT.     

The ecological niche of the consortium “Pelochromatium roseum”

A dense accumulation of the phototrophic consortium “Pelochromatium roseum” in a small, eutrophic, freshwater lake (Dagowsee, Brandenburg, Germany) was investigated. Within the chemocline, the number of epibionts of the consortia represented up to 19% of the total number of bacteria. Per “P. roseum” a mean value of 20 epibionts was determined. Similar to other aquatic habitats, consortia in the Dagowsee were found only at low light intensities (< 7 μmol quanta m^–2 s^–1) and low sulfide concentrations (0–100 μM). In dialysis cultures of “P. roseum”, bacterial cells remained in a stable association only when incubated at light intensities between 5 and 10 μmol quanta m^–2 s^–1. Intact consortia from natural samples had a buoyant density of 1046.8 kg m^–3, which was much higher than that of ambient chemocline water (995.8 kg m^–3). Under environmental conditions and without motility, this density difference would result in rapid sedimentation of consortia toward the lake bottom. Our results indicate that (1) consortia are adapted to a very narrow regime of light intensities and sulfide concentrations, (2) motility and tactic responses must be of ecological significance for the colonization of the free water column of lakes, and (3) phototrophic growth of consortia can be explained only by a cycling of sulfur species in the chemocline, possibly within the consortia themselves. Received: 27 May 1997 / Accepted: 16 September 1997     

Contents of <Emphasis Type="Italic">Trans</Emphasis>-resveratrol in Korean Grape Cultivars,including “Kyoho”

Concentrations of trans-resveratrol were analyzed in 36 Korean-grown grape cultivars, including cv. Kyoho. This cultivar has large irregular berries and a deep-black skin and accounts for >15% of all grapevines grown in Korea. The content of trans-resveratrol is an important quality parameter, and its pattern of variability increased gradually until the time of harvest. Its distribution also fluctuated significantly among leaves, seeds, and exocarps, with the highest amount (1,477 μg g⁻¹ dry weight) occurring in the leaves. Among all cultivars evaluated here, trans-resveratrol contents were significantly higher in “Cheongsoo” and “High Bailey,” their levels being 50% above the overall mean (i.e., 2.0-mg g⁻¹ dry weight), whereas 14 cultivars had contents that were 10% less than that mean value     

Voiceprint identification and its application to sociological studies of wild Japanese monkeys (Macaca fuscata yakui)

Japanese monkeys often exchange the particular vocal sound, “coo,” especially when they feed or move as a group. It was considered that the “coo” sound had no positive social meaning, perhaps because the “coo” sound network and its function were hidden behind other behavioral observations. For identification of the vocalizer only from hearing the “coo” sound, three phonetic values, i.e., the “fundamental,” “duration,” and “formants,” plus other characteristics were used as indices of voiceprints. The results indicated that these were effective for identifying the vocalizer in two-thirds of the adults in the study troop which was composed of 12 adults and 16 immature members. The “coo” sound exchange network among the troop members (adults) was drawn on the basis of the voiceprint identification. The network showed three characteristics as follows: (1) matriarchs of the kin-groups frequently exchanged “coo” sounds with each other; (2) the other females exchanged “coo” sounds mostly within their own kin-groups; and (3) males seldom participated in the “coo” sound exchange. This suggests that “coo” sound exchange plays a central role for the matriarch of kin-groups in binding each kin-group and, ultimately, in binding all members together into an organized troop.     

Physiology and tactic response of the phototrophic consortium “Chlorochromatium aggregatum”

The phototrophic consortium “Chlorochromatium aggregatum” was enriched from sediment samples of a eutrophic freshwater lake and was maintained at high numbers in anoxic sulfide-reduced medium. Growth of intact consortia was observed only in the light and in the presence of 2-oxoglutarate as an organic carbon source. Consortia of “C. aggregatum” reached maximum growth rates at light intensities ≥ 5 μmol quanta m^–2 s^–1. Of ten compounds tested, sulfide, thiosulfate, 2-oxoglutarate, and citrate served as a chemoattractant for “C. aggregatum”. When incubated in the presence of sulfide and in the light, epibionts reduced the fluorochrome 5-cyano-2,3-di-4-tolyl-tetrazolium chloride (CTC). Reduction of CTC was not observed in the presence of the uncoupler carbonyl cyanide m-chlorophenylhydrazone (CCCP) or in the dark, indicating that sulfide serves as an electron donor for the phototrophic epibiont. Motile consortia accumulated scotophobically in microcuvettes at a wavelength of 740 nm. Since this wavelength corresponds to the position of the absorption maximum of bacteriochlorophylls c or d, the photosynthetic pigments are most likely the photoreceptors of the scotophobic response. It is concluded that, within the consortia, a rapid interspecies signal transfer occurs between the nonmotile, green-colored epibiont and the motile, colorless central bacterium. Received: 27 May 1997 / Accepted: 5 September 1997     

New species of Pogonophryne (Pisces, Artedidraconidae) from the Bellingshausen Sea, Antarctica

A new species of notothenioid fish, Pogonophryne bellingshausenensis n. sp., is described from the Bellingshausen Sea, Antarctica. The new species belongs to the dorsally-spotted “mentella” group of the genus and is characterized by having a short (about 13% SL) mental barbel with a short (about 16% of barbel length), narrow (barely wider than the stalk), and relatively inconspicuous terminal expansion composed of short, irregular, fingerlike processes. Compared to most other dorsally-spotted species of Pogonophryne (“barsukovi”, “marmorata”, and “mentella” groups), P. bellingshausenensis has a relatively wide (about 7% SL) interorbital region. An unspotted patch on the median dorsal surface of the head, posterior to the posttemporal ridges and anterior to the first dorsal fin, has not been observed previously in any dorsally-spotted species. The holotype was collected at 1,947 m, one of the deepest records for any species of Pogonophryne. A revised key to the ten species of the “mentella” group of Pogonophryne is also provided.     

Lead,copper, zinc,and magnesium levels in hair of children and young people with some disorders of the osteomuscular articular system

The lead, copper, zinc, and magnesium contents of scalp hair taken from 173 children aged 1–15 yr and young people (16–18 yr) with certain disorders of the osteomuscular articular system (osteomuscular pains of unknown origin, once described as “growing pains”) were measured, using the flame atomic absorption spectrometry method, and then compared with those of 108 normal, healthy children. The research showed increased average levels of lead (a statistically significant p<0.05 in both the overall group of children, and in those over 11 yr old), and zinc (increased in the total group, in a statistically significant way at p<0.10 only in adolescents over 15 yr old) and decreased levels of copper (although not significantly) in the hair of children suffering from “rheumatic” diseases, as compared with controls. The magnesium levels for the total group of ill children were admittedly enhanced, but in the youngest children, the levels were reduced. The values of the Mg/Pb and Mg/Zn ratios were lower (in the youngest children, 70% decrease of the Mg/Pb ratio) and Zn/Cu were higher in the group of children suffering from rheumatic diseases than in the healthy children. The difference of Mg/Pb ratio between the total controls and rheumatic subjects was statistically significant at p<0.05 and the Zn/Cu at p<0.10. The Mg/Zn ratio was not statistically significant.     

Effects of modulation of GABA-and noradrenergic transmission on impulse activity of neurons of the cat motor cortex related to realization of an operant reflex to the action of two signals

On unanesthetized cats trained to perform placing movements to the action of two subsequent signals (warning and imperative stimuli), we examined reflex-related impulse activity (IA) of neurons of the motor cortex (field 4) and simultaneous changes in the “slow” cortical potentials (SCP) in the vertex zone. In almost all cases under study, the shift in the SCP toward negativity was associated with a decrease in the frequency of IA within interstimulus intervals; this corresponded to a period of focusing of the animal’s attention on the expected imperative stimulus. Using a microiontophoretic technique, we tried to elucidate the role of GABA-and adrenergic cerebral systems in the genesis of such inhibitory periods. We conclude that, independently of each other but synchronously, both these systems can be involved in the maintenance of processes of active inhibition in the cerebral cortex under conditions of realization of an operant reflex. Neirofiziologiya/Neurophysiology, Vol. 39, No. 1, pp. 62–68, January–February, 2007.     

Two new“Meganthropus” mandibles from Java

There are now eleven known mandibular pieces from the Lower and Middle Pleistocene of Java, all but one being from the Sangiran site. All of these have been assigned toHomo erectus by most authorities, while others have suggested as many as four different hominoid taxa. Two of the mandibles, Sangiran 33 (Mandible H) and“Meganthropus”D (no Sangiran number yet assigned), are described here for the first time. The two new mandibles come from the Upper Pucangan Formation and date approximately 1.2–1.4 Myr. They are morphologically compatible with other“Meganthropus” mandibles described from Java. Despite attempts by numerous authorities to place all the Sangiran hominid mandibles in the species,H. erectus, the range of variation in metric and nonmetric features of the“Meganthropus” hominids is clearly beyond the know variation found inH. erectus. “Meganthropus” could represent a speciation from the well-knownH. erectus.     

Branching dendrites with resonant membrane: a “sum-over-trips” approach

Dendrites form the major components of neurons. They are complex branching structures that receive and process thousands of synaptic inputs from other neurons. It is well known that dendritic morphology plays an important role in the function of dendrites. Another important contribution to the response characteristics of a single neuron comes from the intrinsic resonant properties of dendritic membrane. In this paper we combine the effects of dendritic branching and resonant membrane dynamics by generalising the “sum-over-trips” approach (Abbott et al. in Biol Cybernetics 66, 49–60 1991). To illustrate how this formalism can shed light on the role of architecture and resonances in determining neuronal output we consider dual recording and reconstruction data from a rat CA1 hippocampal pyramidal cell. Specifically we explore the way in which an I _h current contributes to a voltage overshoot at the soma.     

Warburg,me and Hexokinase 2: Multiple discoveries of key molecular events underlying one of cancers’ most common phenotypes,the “Warburg Effect”, i.e., elevated glycolysis in the presence of oxygen

As a new faculty member at The Johns Hopkins University, School of Medicine, the author began research on cancer in 1969 because this frequently fatal disease touched many whom he knew. He was intrigued with its viscous nature, the failure of all who studied it to find a cure, and also fascinated by the pioneering work of Otto Warburg, a biochemical legend and Nobel laureate. Warburg who died 1 year later in 1970 had shown in the 1920s that the most striking biochemical phenotype of cancers is their aberrant energy metabolism. Unlike normal tissues that derive most of their energy (ATP) by metabolizing the sugar glucose to carbon dioxide and water, a process that involves oxygen-dependent organelles called “mitochondria”, Warburg showed that cancers frequently rely less on mitochondria and obtain as much as 50% of their ATP by metabolizing glucose directly to lactic acid, even in the presence of oxygen. This frequent phenotype of cancers became known as the “Warburg effect”, and the author of this review strongly believed its understanding would facilitate the discovery of a cure. Following in the final footsteps of Warburg and caught in the midst of an unpleasant anti-Warburg, anti-metabolic era, the author and his students/collaborators began quietly to identify the key molecular events involved in the “Warburg effect”. Here, the author describes via a series of sequential discoveries touching five decades how despite some impairment in the respiratory capacity of malignant tumors, that hexokinase 2 (HK-2), its mitochondrial receptor (VDAC), and the gene that encodes HK-2 (HK-2 gene) play the most pivotal and direct roles in the “Warburg effect”. They discovered also that like a “Trojan horse” the simple lactic acid analog 3-bromopyruvate selectively enters the cells of cancerous animal tumors that exhibit the “Warburg effect” and quickly dissipates their energy (ATP) production factories (i.e., glycolysis and mitochondria) resulting in tumor destruction without harm to the animals.     

Quantum Information Processing in the Wall of Cytoskeletal Microtubules

Microtubules (MT) are composed of 13 protofilaments, each of which is a series of two-state tubulin dimers. In the MT wall, these dimers can be pictured as “lattice” sites similar to crystal lattices. Based on the pseudo-spin model, two different location states of the mobile electron in each dimer are proposed. Accordingly, the MT wall is described as an anisotropic two-dimensional (2D) pseudo-spin system considering a periodic triangular “lattice”. Because three different “spin-spin” interactions in each cell exist periodically in the whole MT wall, the system may be shown to be an array of three types of two-pseudo-spin-state dimers. For the above-mentioned condition, the processing of quantum information is presented by using the scheme developed by Lloyd.     

Allometric Effects of <Emphasis Type="Italic">Agriophyllum squarrosum</Emphasis> in Response to Soil Nutrients,Water, and Population Density in the Horqin Sandy Land of China

We monitored the allometric effects for greenhouse-grown Agriophyllum squarrosum plants in response to variations in population density and the availability of soil nutrients and water. Biomass allocations were size-dependent. The plasticity of roots, stems, leaves, and reproductive effort was “true” in response to changes in nutrient content. At a low level of soil minerals, plants allocated more resources to the development of roots and reproductive organs than to leaves, but data for stem allocations were consistent for tradeoffs between the effects of nutrients and plant size. The plasticities of leaf allocation and reproductive effort were “true” whereas those of root and stem allocations were “apparent” in response to fluctuations in soil water, being a function of plant size. Decreasing soil water content was associated with higher leaf allocation and lower reproductive effort. Except for this “apparent” plasticity of leaf allocation, none was detected with population density on biomass allocation. Architectural traits were determinants of the latter. For roots, the determining trait was the ratio of plant height to total biomass; for stems and reproduction, plant height; and for leaves, the ratio of branch numbers to plant height.     

Specific detection of green sulfur bacteria by in situ hybridization with a fluorescently labeled oligonucleotide probe

An oligodeoxynucleotide probe (GSB-532) specific for green sulfur bacteria was developed. Highly stringent hybridization conditions were established using whole cells of Chlorobium limicola DSM249 immobilized on glass slides. At a formamide concentration of 10%, the optimum specificity was reached at 47 °C. When a conventional fixation procedure was used, a conspicuous autofluorescence developed within the cells. This autofluorescence was due to the liberation of bacteriochlorophyll by the detergent Triton X-100 and a subsequent conversion to bacteriopheophytin and related compounds. The signal-to-noise ratio could be increased by a final dehydration of the samples with methanol. Finally, the method was adapted to the hybridization of natural samples collected on polycarbonate membrane filters. In situ hybridization of pure cultures, various enrichments, and natural samples from the chemocline of a freshwater lake confirmed that probe GSB-532 hybridized exclusively to cells of green sulfur bacteria. Our protocol allows the highly specific detection of green sulfur bacteria in water samples and a rapid screening of natural bacterial communities. Employing probe GSB-532, the phylogenetic affiliation of the epibionts in “Chlorochromatium aggregatum” and “Pelochromatium roseum” could be demonstrated for the first time. Received: 26 October 1998 / Accepted: 7 January 1999     

Composition of phytobenthos in “lab-lab”, a periphyton-based extensive aquaculture technology for milkfish in brackishwater ponds during dry and wet seasons

The study compared the species composition of phytoperiphyton (“lab-lab”) present in ponds when gradually filled with water weekly to depths of 5, 10, 15 and 30 cm between the wet and dry seasons, for one month before the stocking of fish was studied. This was done during the dry season (March–April, 2003) and wet season (June–July, 2002). Periphyton was allowed to grow on 24 artificial substrates set at equal distances in a 1000 m² pond. “Lab-lab” that colonized the artificial substrates and that on the pond surrounding the substrates were scraped off from a measured surface area. Simultaneously, water was collected for the analysis of physical, chemical and biological parameters. Sampling was done bi-weekly coinciding with 2 and 7 days submergence at a desired depth before adjusting the water level. The major algae consisted of the diatoms (Bacilliarophyta), the blue green algae (Cyanobacteria), and the green algae (Chlorophyta). The diatoms were dominant during the dry season while the cyanobacteria dominated during the wet season. Twenty eight genera were observed during the dry season and 25 genera were noted in the wet season. Variation in genera and density that were observed every sampling period, was influenced by environmental conditions and the incoming water. The total algal density ranged from 100.7 × 10⁸ – 855.1 × 10⁸ and to 24.7 × 10⁸ – 83.9 × 10⁸ organisms.m⁻² during the dry and wet seasons, respectively. Presented at the 6th Meeting of the Asian Pacific Society of Applied Phycology, Manila, Philippines.     

Sangiran 5,(“Pithecanthropus dubius”), homo erectus, “Meganthropus,” orPongo?

There are now eleven known mandibular remains from the Lower and Middle Pleistocene of Java, all but one being from the Sangiran site. All of these have been assigned toHomo erectus by most workers, while others have suggested as many as four different hominoid taxa. The author finds that the jaws cannot be a homogeneous sample. Morphologically, they are a mixture of undoubtedH. erectus, “H. meganthropus,” and possibly a pongid. If the jaws are allH. erectus then they have a sexual dimorphism exceeding that of modern gorillas. The case of“Pithecanthropus dubius” (Sangiran 5) is even less certain; even its hominid status is disputed. If it is indeedHomo it must be placed with the other“H. meganthropus” specimens. Its size and morphology are well beyond the known range anyH. erectus.     

The Taxonomic and Evolutionary History of Fossil and Modern Balaenopteroid Mysticetes

Balaenopteroids (Balaenopteridae + Eschrichtiidae) are a diverse lineage of living mysticetes, with seven to ten species divided between three genera (Megaptera, Balaenoptera and Eschrichtius). Extant members of the Balaenopteridae (Balaenoptera and Megaptera) are characterized by their engulfment feeding behavior, which is associated with a number of unique cranial, mandibular, and soft anatomical characters. The Eschrichtiidae employ suction feeding, which is associated with arched rostra and short, coarse baleen. The recognition of these and other characters in fossil balaenopteroids, when viewed in a phylogenetic framework, provides a means for assessing the evolutionary history of this clade, including its origin and diversification. The earliest fossil balaenopterids include incomplete crania from the early late Miocene (7–10 Ma) of the North Pacific Ocean Basin. Our preliminary phylogenetic results indicate that the basal taxon, “Megaptera” miocaena should be reassigned to a new genus based on its possession of primitive and derived characters. The late late Miocene (5–7 Ma) balaenopterid record, except for Parabalaenoptera baulinensis and Balaenoptera siberi, is largely undescribed and consists of fossil specimens from the North and South Pacific and North Atlantic Ocean basins. The Pliocene record (2–5 Ma) is very diverse and consists of numerous named, but problematic, taxa from Italy and Belgium, as well as unnamed taxa from the North and South Pacific and eastern North Atlantic Ocean basins. For the most part Pliocene balaenopteroids represent extinct species and genera and reveal a greater degree of morphological diversity than at present. The Pleistocene record is very limited and, unfortunately, fails to document the evolutionary details leading to modern balaenopteroid species diversity. It is evident, however, that most extant species evolved during the Pleistocene. Morphological and molecular based phylogenies support two competing hypotheses concerning relationships within the Balaenopteroidea: (1) balaenopterids and eschrichtiids as sister taxa, and (2) eschrichtiids nested within a paraphyletic Balaenopteridae. The addition of fossil taxa (including a new Pliocene species preserving a mosaic of balaenopterid and eschrichtiid characters) in morphological and “total evidence” analyses, offers the potential to resolve the current controversy concerning the possible paraphyly of Balaenopteridae.     

Tank cultivation of <Emphasis Type="Italic">Ulva prolifera</Emphasis> in deep seawater using a new “germling cluster” method

A new “germling cluster” method is proposed for tank cultivation of seaweed in a free-floating form. This method was applied to the tank cultivation of Ulva prolifera using deep seawater (DSW) pumped up from over 300 m depth off the cape of Muroto in southwest Japan. Numerous zoids of U. prolifera were induced by cutting thalli into 1–2 mm long pieces. Three days after fragment production, the zoids were released. The zoid suspension was concentrated to a density of more than 10⁴ zoids per mL medium, and placed in a Petri dish for culture. The dense, germinating zoids began to adhere to each other and form aggregations. The germling aggregations were then removed from the bottom of the dish and torn into a large number of small “germling clusters” using an electric mixer. Each cluster contained 10–100 germlings. Once the germling clusters had attained more than 5 mm diameter in culture, they were transplanted as free-floating forms to a 500 L outdoor tank with continuous aeration, to which DSW was supplied at an exchange rate of 3 volumes per day. As a result, the average daily growth rate (DGR) in the tank throughout the year was 37%, though the DGR fluctuated with seasonal temperature changes.