Electron microscopical study of synaptic glomeruli in cerebellum transplanted to the anterior eye chamber

Fetal cerebellar anlage from rat fetuses of 15-16 operational days were grafted into the anterior chamber of the eye of adult female albino rat recipients. Survival time of the transplants--containing both cerebellar cortex and cerebellar nuclei--was 2 to 2 1/2 months. Electron microscopical (EM) studies of the thin, under-developed granular layer of the laminated cerebellar cortex revealed the presence of well differentiated cerebellar glomeruli, surrounded by granule cell perikarya. As in the normal cerebellar cortex, the central profile of the glomerular complex was the large mossy terminal, containing spheroid synaptic vesicles, and forming synaptic contacts with dendrites and dendritic digits of the granule cells. Golgi cell axonal varicosities, containing ovoid or pleomorphic synaptic vesicles were found also on the periphery of the glomeruli. In addition, in several synaptic glomeruli, a third neuronal element was also observed, containing flat, discoidal vesicles and receiving synaptic contacts from mossy and Golgi axons, but being also presynaptic to granule cell dendrites. It is suggested that all mossy terminals in the cerebellar transplant originate from the cerebellar nucleus. Morphological evidence is also provided that the presynaptic dendrite-like processes--never found in normal cerebellar cortex--are also processes of nuclear neurons.     

Histidine decarboxylase. Purification from fetal rat liver, immunologic properties, and histochemical localization in brain and stomach

Histidine decarboxylase from fetal rat liver was purified to near-homogeneity. The purified enzyme has a molecular weight of 210,000, and appears to contain two subunits with molecular weights of 145,000 and 66,000, respectively. The enzyme is inhibited by heavy metals such as Hg2+ and Zn2+ and sulfhydryl-reactive compounds such as 5,5'-dithiobis-2-nitrobenzoic acid. The enzyme is partially dependent on exogenous pyridoxal phosphate. Extensive dialysis results in 50% loss of enzyme activity which can be fully recovered by adding pyridoxal phosphate. Affinity of pyridoxal phosphate for the apoenzyme is 0.1 microM at pH 6.8. Antibody against purified histidine decarboxylase was raised in rabbits. The antibody has been employed in immunohistochemical studies to visualize histidine decarboxylase containing cells and neuronal processes in rat stomach and brain, respectively. Immunologic studies indicate that histidine decarboxylase from brain, gastric mucosa, and fetal rat liver share common antigenic properties.     

Organ-specific crystalline structures of ferritin cores inβ-thalassemia/hemoglobin E

Summary The cores of ferritins isolated from different organs of human subjects with-thalassemia/hemoglobin E (-thal/HbE) disease have different size distributions and crystallinities depending on the source organ. These patients have not been treated by hypertransfusion regimen or iron chelation therapy.-Thal/HbE spleens and livers yield ferritin cores which are less crystalline than those isolated from normal spleens and livers, reflecting the more rapid deposition of iron in the diseased state. Ferritins isolated from the hearts and pancreases of-thal/HbE subjects were found to have larger, more crystalline cores than those from the-thal/HbE livers and spleens, possibly as a consequence of the role of the heart and pancreas as long-term iron deposition sites in this iron overload pathology.     

Hepatic α1 and β adrenergic receptors in various animal species

Summary Plasma membranes were isolated from the livers of various animal species representing the four vertebrate classes: Amphibia, Reptilia, Aves and Mammalia. These liver plasma membranes displayed comparable levels of purity as judged by marker enzyme analysis. The activities of the two marker enzymes, 5-nucleotidase and -glutamyltranspeptidase displayed striking, and quite different, species-dependent differences, with no apparent relationship to phylogeny. ₁ and -adrenergic receptors were characterized in isolated liver plasma membranes by radioligand binding techniques. The hepatic -adrenergic receptor was found to be expressed in all animals studied; the hepatic ₁-adrenergic receptor was absent in Amphibia and Reptilia, co-expressed with the receptor in Aves, and dominant over the receptor in Mammalia. These results suggest that, in liver, the -adrenergic receptor is more primitive while the ₁-adrenergic receptor is of a more recent phylogenetic origin. It is proposed that the latter may have evolved in conjunction with hepatic sympathetic innervation.     

In vitro flower formation from thin epidermal cell layers of a partial somatic hybrid between Petunia hybrida (Hort.) and Nicotiana plumbaginifolia (Viv.)

In vitro flowers have been obtained by culturing thin epidermal cell layers of a partial somatic intergeneric hybrid. The phenotype of these flowers differs from that of flowers formed on seed-grown plants (in situ flowers) and from that of flowers of either parental line. In addition, modifications in the phenotype were observed when cultures were sustained for more than four months. Dimorphic leaves present in juvenile and adult stages of mother plants of Nicotiana plumbaginifolia and the somatic hybrid were formed on different ends of the thin epidermal cell layers. No anomalies were observed during microsporogenesis and in the meiotic and mitotic figures of the somatic hybrid, which resembled those of Nicotiana plumbaginifolia.     

NMR structure of the pseudo-receiver domain of CikA

The circadian input kinase (CikA) is a major element of the pathway that provides environmental information to the circadian clock of the cyanobacterium Synechococcus elongatus. CikA is a polypeptide of 754 residues and has three recognizable domains: GAF, histidine protein kinase, and receiver-like. This latter domain of CikA lacks the conserved phospho-accepting aspartyl residue of bona fide receiver domains and is thus a pseudo-receiver (PsR). Recently, it was shown that the PsR domain (1) attenuates the autokinase activity of CikA, (2) is necessary to localize CikA to the cell pole, and (3) is necessary for the destabilization of CikA in the presence of the quinone analog 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB). The solution structure of the PsR domain of CikA, CikAPsR, is presented here. A model of the interaction between the PsR domain and HPK portion of CikA provides a potential explanation for how the PsR domain attenuates the autokinase activity of CikA. Finally, a likely quinone-binding surface on CikAPsR is shown here.     

Repair of oxidative guanine damage in plasmid DNA by indoles involves proton transfer between complementary bases

We have used the single electron oxidizing agent (SCN)(2)(*)(-) (generated by gamma-irradiation of aqueous thiocyanate) to produce guanyl radicals in plasmid DNA. The stable product(s) formed from these radicals can be detected after conversion with a base excision repair endonuclease to single strand breaks. The yield of enzyme-induced breaks is decreased by the presence during irradiation of indole compounds. Rate constants for the reduction of DNA guanyl radicals by these indoles can be calculated from the concentration dependence of the attenuation in the yield of enzyme sensitive sites. Indoles bearing electron-donating groups (methoxy or methyl) appear to react at the diffusion-controlled rate, but those bearing electron-withdrawing groups (cyano or nitro) are significantly less reactive. At physiological pH values, the reduction of a DNA guanyl radical involves the transfer of a proton as well as an electron. Comparison of the kinetic results with literature thermodynamic data suggests that the source of this proton is the complementary base-paired cytosine.     

Xenin-25 Potentiates Glucose-dependent Insulinotropic Polypeptide Action via a Novel Cholinergic Relay Mechanism

The intestinal peptides GLP-1 and GIP potentiate glucose-mediated insulin release. Agents that increase GLP-1 action are effective therapies in type 2 diabetes mellitus (T2DM). However, GIP action is blunted in T2DM, and GIP-based therapies have not been developed. Thus, it is important to increase our understanding of the mechanisms of GIP action. We developed mice lacking GIP-producing K cells. Like humans with T2DM, “GIP/DT” animals exhibited a normal insulin secretory response to exogenous GLP-1 but a blunted response to GIP. Pharmacologic doses of xenin-25, another peptide produced by K cells, restored the GIP-mediated insulin secretory response and reduced hyperglycemia in GIP/DT mice. Xenin-25 alone had no effect. Studies with islets, insulin-producing cell lines, and perfused pancreata indicated xenin-25 does not enhance GIP-mediated insulin release by acting directly on the β-cell. The in vivo effects of xenin-25 to potentiate insulin release were inhibited by atropine sulfate and atropine methyl bromide but not by hexamethonium. Consistent with this, carbachol potentiated GIP-mediated insulin release from in situ perfused pancreata of GIP/DT mice. In vivo, xenin-25 did not activate c-fos expression in the hind brain or paraventricular nucleus of the hypothalamus indicating that central nervous system activation is not required. These data suggest that xenin-25 potentiates GIP-mediated insulin release by activating non-ganglionic cholinergic neurons that innervate the islets, presumably part of an enteric-neuronal-pancreatic pathway. Xenin-25, or molecules that increase acetylcholine receptor signaling in β-cells, may represent a novel approach to overcome GIP resistance and therefore treat humans with T2DM.     

Regional material flow behaviors of agro‐food processing craft villages in Red River Delta,Vietnam

The economic reform “??i M?i” in 1986 has rapidly increased the number of craft villages in Vietnam, especially in the Red River Delta (RRD) leading to environmental degradation. This article presents an assessment of environmental and resource issues of agro‐Food Processing Craft Villages (FPCVs) in RRD using a refined approach to material flow analysis focusing on consistent quantification of uncertainty with particular attention to secondary and empirical data that are often faced in material flow analyses in transition economies. Material flows of agro‐Food Processing including eight types of production were examined and linked to activities of private Households, Rice Cultivation, and Pig Farming in a model called Red River Delta. Materials investigated were Goods (i.e., total materials), organic carbon (org.C), nitrogen (N), and phosphorus (P). The findings reveal material cycles are almost entirely open, that is, the materials used in FPCVs do not recycle within the region. From ～10.5 million tons/year of imported Goods used for agro‐Food Processing, final products and utilized materials account for minor fractions (～5%, by weight). Conversely, the majority (88%) is directly discharged. Materials accumulated as stocks represent 1% of Goods (100,000 tons/year), 21% of org.C (～34,000 tons/year), 42% of N (～1,300 tons/year), and 57% of P (～300 tons/year), whose substance concentrations vastly exceed natural resilience capacities. Although agro‐Food Processing accounts for negligible material shares in Red River Delta, FPCVs pollution is severe at local levels due to the location of home‐based production. Several options for closing material loops at various system scales are recommended for environmental and resource management of FPCVs. The material flow analysis results provide a database that may be used as a decision support tool for production establishments in craft villages and relevant authorities in setting priorities on environmental planning and resource management. This article met the requirements for a gold – silver JIE data openness badge described at http://jie.click/badges .