Catecholaminergic innervation of GRF-containing neurons in the rat hypothalamus revealed by electron-microscopic cytochemistry

Summary The Catecholaminergic innervation of neurons containing growth hormone-releasing factor (GRF) was examined by use of a method which combined either 5-hydroxydopamine (5-OHDA) uptake or autoradiography after intraventricular injection of ³H-noradrenaline with immunocytochemistry for GRF in the same tissue sections at the electron-microscopic level. In the ventrolateral part of the arcuate nucleus of the rat hypothalamus a large number of immunonegative axon terminals were found to make synaptic contact with GRF-like immunoreactive (GRF-LI) cell bodies and processes. ³H-noradrenaline autoradiography or 5-OHDA-labeling combined with GRF immunocytochemistry revealed that axon terminals labeled with ³H-noradrenaline or 5-OHDA make synaptic contact with the GRF-LI nerve cell bodies and processes. These findings indicate that catecholamine-containing neurons innervate GRF neurons to regulate GRF secretion via synapses in the rat arcuate nucleus.     

Extraction and quantitation of astaxanthin from Phaffia rhodozyma

Summary The rapid, quantitative release of astaxanthin and other carotenoids from the yeast Phaffia rhodozyma is described. Hashed cells are ruptured with dimethylsulfoxide (DMSO) and carotenoids extracted into an organic solvent. Extraction and spectrophotometric quantitation of total carotenoids is rapid, reproducible and only small volumes (0.1–2 ml) of culture are required. HPLC analysis in normal phase silica gel column indicates that astaxanthin comprises 65–95% of the total pigmented carotenoids of P. rhodozyma.     

Distribution of Leu 7 (HNK-1) antigen in human digestive organs: an immunohistochemical study with monoclonal antibody

Summary Leu 7 immunoreactivity was demonstrated with the indirect peroxidase-labelled antibody method on frozen and paraffin-embedded tissue sections of human digestive organs. Anti-Leu 7 monoclonal antibody, which allegedly detects mononuclear cells with natural killer or killer activity, recognized lymphoid cells among intestinal epithelial cells and in the germinal centres of solitary lymphoid follicles of small and large intestine, and a few in gallbladder, liver and the lamina propria of the intestine. In addition, peripheral nerve fibres, endocrine cells in the gut and pancreas and carcinoid and islet cell tumours were also positively stained. At the ultrastructural level, Leu 7 antigen was localized on the plasma membrane of granulated lymphoid cells in the gut mucosa and on the secretory granules of intestinal endocrine cells. In normal pancreas, Leu 7 immunoreactivity was demonstrated in most cells containing pancreatic polypeptide and in many cells containing somatostatin or glicentin. Insulin-containing cells, however, lacked Leu 7 immunoreactant. These findings were obtained in both frozen sections and paraffin-embedded sections. The possible cross-reactivities of monoclonal antibodies are discussed as they raise an important caveat in immunohistochemical studies using these antibodies.     

Use of the Stereoisomers of Isoleucine by Lactobacillus fermenti

The use of four stereoisomers of isoleucine by Lactobacillus fermenti strain 36 was studied in detail. All four isoleucine isomers were used for growth in the presence of vitamin B(6) compounds, but only l-isoleucine was active in the absence of these vitamins. Of the vitamin B(6) compounds, pyridoxal and pyridoxamine were equally more effective than pyridoxine for the utilization of these isomers. Lowering the initial pH, decreasing the amounts of leucine and valine, and adapting the organism to d-alloisoleucine medium accelerated the use of isoleucine isomers. Thus, the conditions were established under which respective isomers gave the same growth response, and these findings were applied to the separate microbiological assay of l-isoleucine and total isoleucine isomers.     

Nucleosomelike structures associated with chromosomes of the archaebacterium Halobacterium salinarium.

Chromosomes of the halophilic archaebacterium Halobacterium salinarium were examined by electron microscopy after being spread onto water. The major part of the chromosomal DNA was associated with protein particles with diameter of 9.4 nm, arranged tandemly along the DNA fibers. Thus, the primary structure of the chromosome resembles that of eucaryote chromosomes.     

Age-dependent aluminum accumulation in the human aorta and cerebral artery

The purpose of this study was to determine the extent of aluminum (Al) accumulation in the human aorta and cerebral arteries. The Al contents in the aortae and in the cerebral arteries from 23 human subjects was determined by inductively coupled plasma atomic emission spectrophotometry (ICP-AES). The subjects' age range was 45–99-yr-old; 15 of the subjects were males and 8 were females. Al was detected in twelve aortae and in six cerebral arteries, when the entire specimen was analyzed. Two specimens where Al was found in the cerebral arteries contained no Al in the aorta. No relationship to the subject's sex was found. When related to age, two groups were established. Group L (45–75 yr old) and group H (>75 yr old), which exhibited aortal Al concentrations of 33.3 and 72.7%, respectively. When the aortic wall was dissected into the tunica intima, media, and adventitia, Al was found mainly in the tunica media. In the aorta, significant relationships were found between Al and phosphorus (P) levels (r=0.801,p<0.01) and between Al and calcium (Ca) (r=0.661,p<0.05). We have concluded that Al accumulation is age-dependent and that it occurs both in the aorta and in the cerebral artery. In the aorta, accumulation occurs mainly in the tunica media. Both P and Ca appear to enhance aortal Al accumulation.     

Phosphorylation of a Protein (pp56) is Related to the Regeneration of Rice Cultured Suspension Cells

Short-term cultured suspension cells of rice (Oryza sativa L.)are capable of regeneration, but not in long-term culture. Forclarification of the mechanism of regeneration, protein phosphorylationin short-term and long-term cultured suspension cells was comparedby two dimensional- polyacrylamide gel electrophoresis. A 56kDa protein having an isoelectric point of 4.5 was phosphorylatedin vitro in short-term cultured suspension cells, but was notphosphorylated after regeneration. This protein in longtermcultured suspension cells remained phosphorylated after transferto the regeneration medium. However, using an antibody raisedagainst this protein from short-term cultured suspension cells,it was always detected in long-term and short-term culturedsuspension cells after transfer to the regeneration medium.The partial amino acid sequence of the HPLC-purified proteinshowed homology to a calcium-binding protein from maize. Thephosphorylation of the 56 kDa protein (pp56) appears to be associatedwith the regeneration of cultured rice cells. (Received December 11, 1995; Accepted June 3, 1996)     

Antithrombotic effect of topically applied 3-Oxa-Methano-prostaglandin I1 in the microcirculation and antiplatelet functions of its active form

The antithrombotic effect of topical application of the 3-oxamethano-prostaglandin (PG) I₁ analog, SM-10902 in the microcirculation and in vitro antiplatelet functions of its active form SM-10906 were estimated in comparison with PGI₂ and PGE₁. In rat platelets, SM-10906 evoked accumulation of intracellular cyclic adenosine 3′,5′-monophosphate, and exhibited antiaggregatory and disaggregatory activities, which were all enhanced by the phosphodiesterase inhibitor theophylline. Additionally, SM-10906 was shown to inhibit platelet adhesion to collagen in human platelet-rich plasma. PGI₂ and PGE₁ also showed in vitro antiplatelet effects in the order of PGI₂ > SM-10906 ≥ PGE₁. SM-10902 exhibited a dose-dependent antithrombotic effect in the guinea pig mesenteric arteriole by a topical application, and this activity might be exerted by the antiplatelet functions of SM-10906. Although SM-10906, PGI₂ and PGE₁ also showed the antithrombotic effects, SM-10902 was the most potent. In conclusion, the present studies indicate that an external topical preparation of SM-10902 may be useful for the therapy of peripheral circulatory insufficiency.