Immunohistochemical study on the distribution of serotonin fibers in the spinal cord of the dog

Summary Distribution of serotonin fibers in the spinal cord of the dog was investigated by means of a modified PAP method; a rabbit anti-serotonin serum prepared in the laboratory of the authors was used in this study. Serotonin fibers were revealed as PAP-positive dark-brown elements displaying dot-like varicosities (0.5–2.0 m in diameter). In the spinal cord of the dog, the distribution of serotonin fibers is extensive. These fibers occur more densely in more caudal segments and are most prominent at the sacrococcygeal level. From the level of the cervical spinal cord to the upper lumbar region, the descending serotonin fibers are located immediately under the pia mater in the ventrolateral portion of the lateral funiculus. In more caudal segments, serotonin fibers are dispersed throughout the ventral and lateral funiculi. These longitudinal en passage-fibers send numerous transverse collaterals to the gray matter. Serotonin fibers are distributed abundantly in the laminae I and III of the posterior column, while only a few fibers are found in the lamina II (substantia gelatinosa). In the intermediate zone, two descending serotonin pathways, i.e., lateral and medial longitudinal bundles, are observed to coincide topographically with the nucleus intermediolateralis at C8(T1)-L3(L4) and the nucleus intermediomedialis at C1-Co respectively. The former is particularly prominent and communicates with the contralateral bundle via commissural bundles at intervals of 300–500 m. The large motoneurons in the anterior column, especially those in the nucleus myorabdoticus lateralis within the cervical and lumbar enlargements, are closely surrounded by fine networks of serotonin fibers and terminals.Supported by a grant (No. 56440022) from the Ministry of Education, Science and Culture, Japan     

External calcium ions are requisite for fertilization of sea urchin eggs by spermatozoa with reacted acrosomes

That a small amount of external calcium ions is requisite for the fertilization by spermatozoa with reacted acrosomes was found by some simple experiments using jelly-treated sperm of the sea urchin, Hemicentrotus pulcherrimus. When eggs were inseminated with the jelly-treated sperm in artificial seawaters containing calcium at various concentrations, the percentage of fertilization decreased concomitant with the reduction in the amount of external calcium ions, 50% at 40 μM calcium and almost 0% at less than 10 μM. On the other hand, it was observed that both the morphology of the reacted acrosome and the binding capacity of the jelly-treated spermatozoa to eggs were not influenced by the calcium deficiency. These results suggest that external calcium ions are indispensable even for the fertilization processes following sperm binding to eggs after the acrosome reaction, such as penetration of reacted spermatozoa through vitelline layer and/or membrane fusion between egg and spermatozoon.     

Cell development of a green alga,Pleurotaenium nodosum,which was tied by a fiber

Summary Cells of a green alga,Pleurotaenium nodosum, were tied off with thin fibers, after which development of daughter semicells from the small tied mother semicells was examined with a light microscope. Semicells slightly shortened due to tying mostly developed normal sized daughter semicells with four nodes. However, semicells shorter than 1/2 the normal size developed small daughter semicells with fewer nodes. This was interpreted that the daughter semicells of shortened semicells had not enlarged sufficiently to allow formation of four nodes on the cell surface at the initial stage of node formation. The initiation of node formation was recognized as taking place in the contact region between the plasma membrane and the cell wall in plasmolyzed cells. The distance between two neighbouring contact regions was consistent at about 6 m.     

Structural analysis of a Lotus japonicus genome. V. Sequence features and mapping of sixty-four TAC clones which cover the 6.4 mb regions of the genome.

We determined the nucleotide sequences of 64 TAC (transformation-competent artificial chromosome) clones selected from genomic libraries of Lotus japonicus accession Miyakojima MG-20 based on the sequence information of expressed sequence tags (ESTs), cDNAs, genes and DNA markers from L. japonicus and other legumes. The length of the DNA regions sequenced in this study was 6,370,255 bp, and the total length of the L. japonicus genome sequenced so far is 32,537,698 bp together with the nucleotide sequences of 256 TAC clones previously reported. Five hundred forty-eight potential protein-encoding genes with known or predicted functions, 127 gene segments and 224 pseudogenes were assigned to the newly sequenced regions by computer prediction and similarity searches against the sequences in protein and EST databases. Based on the nucleotide sequences of the clones, simple sequence repeat length polymorphism (SSLP) or derived cleaved amplified polymorphic sequence (dCAPS) markers were generated, and each clone was genetically localized onto the linkage map of two accessions of L. japonicus, MG-20 and Gifu B-129. The sequence data, gene information and mapping information are available through the World Wide Web at http://www.kazusa.or.jp/lotus/.     

Structural elucidation of polysaccharide part of glycoconjugate from Treponema medium ATCC 700293.

Glycoconjugates are distributed on the cell surfaces of some small-sized treponemes and have been reported to be completely different from lipopolysaccharides. We separated a glycoconjugate fraction from Treponema medium ATCC 700293, a medium-sized oral spirochete, to assess its immunobiological activities and elucidate the chemical structure of its polysaccharide part using phenol/water extraction, hydrophobic chromatography, and gel filtration. The glycoconjugate showed negligible or weak endotoxic and immunobiological properties. The chemical structure of the polysaccharide part was shown by two-dimensional NMR and MALDI-TOF-MS to be a tetrasaccharide backbone with two amino acids: [-->4)beta-d-GlcpNAc3NAcA(1-->4)beta-d-ManpNAc3NAOrn(1-->3)beta-d-GlcpNAc(1-->3)alpha-D-Fucp4NAsp(1-->] where GlcNAc3NAcA is 2,3-diacetamido-2,3-dideoxyglucuronic acid, ManNAc3NAOrn is Ndelta-(2-acetamido-3-amino-2,3-dideoxymannuronyl)ornithine, and Fuc4NAsp is 4-(alpha-aspartyl)amino-4,6-dideoxygalactose.     

Structural analysis of a Lotus japonicus genome. IV. Sequence features and mapping of seventy-three TAC clones which cover the 7.5 mb regions of the genome.

Using the sequence information of expressed sequences tags (ESTs), cDNAs and genes from Lotus japonicus and other legumes, 73 TAC (transformation-competent artificial chromosomes) clones were selected from a genomic library of L. japonicus accession MG-20, and their nucleotide sequences were determined. The length of the DNA sequenced in this study was 7,455,959 bp, and the total length of the DNA regions sequenced so far is 26,167,443 bp together with the nucleotide sequences of 183 TAC clones previously reported. By similarity searches against the sequences in protein and EST databases and prediction by computer programs, a total of 699 potential protein-encoding genes with known or predicted functions, 163 gene segments and 267 pseudogenes were assigned to the newly sequenced regions. Based oil the nucleotide sequences of the clones, simple sequence repeat length polymorphism (SSLP) or derived cleaved amplified polymorphic sequence (dCAPS) markers were generated, and each clone was located onto the linkage map of two accessions of L. japonicus, Gifu B-129 and Miyakojima MG-20. The sequence data, gene information and mapping information are available through the World Wide Web at http://www.kazusa.or.jp/lotus/.     

Evaluation of respiratory modulation on the pulse wave amplitude in low-birth-weight neonate.

A slow oscillation of sympathetic vasoconstriction (Mayer waves) which is affected by the respiratory movements seems to appear as the fluctuation of pulse wave amplitude (PPG.P-P) in the frequency domain (0.1 Hz). Whether the vasomotor in low frequency has appeared in the pulse wave of the neonate and whether Mayer waves appear as the pulse wave oscillation of the immature low-birth-weight neonate are not fully understood from the point of autonomic nerve regulation mechanism. We therefore analyzed the frequency characteristics of PPG.P-P, respiration wave and its amplitude (RW.P-P) together with the heart rate variability (HRV) to examine the relationships between the frequency spectra.     

High concentration of free trimethyllysine in red blood cells

A high concentration of a basic unidentified amino compound was found in the blood of rats. It was isolated and identified as N epsilon,N epsilon,N epsilon-trimethyllysine by paper chromatography, thin-layer chromatography, high-performance liquid chromatography and amino acid analyzer. It was localized exclusively in red blood cells in the blood of rats. Free trimethyllysine was also determined in the liver, kidney, spleen, brain, muscle, heart and testis of rat. The concentration of free trimethyllysine in red blood cells was more than 10-times as high as that in the other tissues. This compound in red blood cells was found in different species of animals. The relationship between this free trimethyllysine and carnitine was discussed.     

Effects of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) on somatic mutation in a soybean test system.

The mutagenic activity of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) was assayed in heterozygous soybean plants (Y11y11), based on the appearance of mutational spots (yellow, dark green and twin) on the leaves. When soybean seeds were treated with IQ at concentrations of 0.01-0.1 microgram/ml, the frequency of mutational spots per leaf increased significantly in proportion to the concentration of IQ. At higher concentrations IQ was toxic. The mutagenicity of IQ was enhanced by pretreatment with the hepatic S9 fraction from Aroclor-induced rats. The numbers of yellow and dark green spots per leaf increased markedly by the treatment with IQ and S9-activated IQ, but the number of twin spots did not increase.     

Demonstration of the tuberoinfundibular tract of the cat

Summary The distribution of dopaminergic nerve cells in the cat hypothalamus, particularly in the arcuate and periventricular nuclei, and the projections of their axons were studied by fluorescence and electron microscopy after electrothermic coagulation. The majority of these perikarya were located in the arcuate nucleus and the periventricular nucleus dorsocaudal to the optic chiasma. Large lesions caused a wide and diffuse depletion of dopamine fluorescence within the external layer; small lesions caused ipsilateral partial depletion of the dopamine fluorescence. Electron microscopic observations in animals with a lesioned arcuate nucleus revealed that in the external layer degenerating nerve terminals are engulfed by glial processes. In some cases nerve fibers had entirely disappeared and a heavy reactive proliferation of glial processes was observed. Persistence of the form of the median eminence in spite of the extensive degeneration of its nervous elements is considered to depend upon this glial proliferation.Dedicated to Professor W. Bargmann in honour of his 70th birthday