Effects of morphine, enkephalins and naloxone on postprandial gastric acid secretion, gastric emptying and gastrin release in dogs

The effects of intravenous infusions of morphine, met-enkephalin and leu-enkephalin on gastric acid secretion, gastrin release and gastric emptying were investigated in four dogs with gastric cannulas stimulated by a liquid peptone meal. The actions of a potent opiate antagonist, naloxone, used alone or combined with opiates were also studied. Morphine, met-and leu-enkephalin decreased the fractional gastric emptying rate. Acid secretion was decreased by enkephalins and increased by high doses of morphine. Enkephalins and to a lesser degree morphine inhibited gastrin release during the first hour following the administration of the meal. Only leu-enkephalin decreases significantly the integrated gastrin response. Naloxone at the doses used antagonized partly or totally the effects of opiates on gastric emptying but not those on gastric secretion or gastrin release. Naloxone infused alone had no significant effect on the gastric functions tested. These studies indicate that in dogs stimulated by a liquid test meal, enkephalins inhibit gastric emptying, acid secretion and gastrin release. Morphine inhibits gastric emptying and gastrin release and enhances acid secretion.     

Chloroplast DNA evidence for non-random selection of females in an outcrossed population of soybeans [Glycine max (L.)]

Summary Restriction fragment length polymorphisms (RFLPs) were used to assess chloroplast DNA (cpDNA) variation in a population of soybeans subjected to continuous cycles of forced outcrossing. This population was derived by crossing 39 female lines with four male-sterile (Ms₂ms₂) maintainer lines and advancing each generation by selecting only outcrossed seed borne on male-sterile (ms₂ms₂) plants. Analysis of the original 39 female lines revealed three groups based on cpDNA RFLPs. These three groups had been previously documented in soybeans, and the distribution of these groups among the female parents of this population was similar to that observed in germ plasm surveys of soybean. Thirty-four of the female parents had group I cpDNA, 3 had group II, and 2 had group III. Plants collected from this population after seven cycles of outcrossing were scored for four morphological traits (flower color, pubescence color, seed color, and pubescence type) known to be controlled by alleles at single nuclear loci. The frequencies of the phenotypes observed in this study indicated that the population underwent random mating with respect to flower and pubescence color, but deviated from random mating at the other two loci. Analysis of 158 of these same plants collected from the population after seven cycles of outcrossing revealed no individuals with group II or group III cpDNAs. The fixation of the group I cpDNA marker in this outcrossing population was judged to result primarily from selection against individuals in the population with the rare cpDNAs.Published as Paper no. 9640, Journal Series, Nebraska Agric Res Div Project no. 12-187. This research was supported in part by the University of Nebraska-Lincoln Research Council and NIH Biomedical Research Support Grant # RR-07055     

Effect of culture conditions on the NADH/NAD ratio and total amounts of NAD(H) in chemostat cultures of Enterococcus faecalis NCTC 775

Abstract Enterococcus faecalis was grown in chemostat culture on various energy sources at dilution rates ranging from 0.05 h⁻¹ to 0.5 h⁻¹, under both aerobic and anaerobic conditions. NADH/NAD ratios and total nicotinamide adenine dinucleotide pool size (NAD(H)) were determined. It was found that the NADH/NAD ratio was controlled by the steady state product concentrations rather than by the degree of reduction of the energy source. Highest ratios were observed when NADH was reoxidized via ethanol formation, whereas in aerobic cultures, in which predominantly acetate was produced and oxidation of NADH occurred via the NADH oxidase, ratios were lowest. Addition of ethanol to the medium resulted in an increase of the NADH/NAD ratio, both aerobically and anaerobically. The total amount of NAD(H) was found to be influenced by the culture conditions. Under anaerobic conditions, the NADH oxidation (NAD reduction) rate appeared to correlate with the total amount of nicotinamide nucleotides. In contrast, no effect of the culture conditions on the total amount of NAD(H) was observed in aerobically grown cells.     

Crystal structures of archaemetzincin reveal a moldable substrate-binding site

Background

Archaemetzincins are metalloproteases occurring in archaea and some mammalia. They are distinct from all the other metzincins by their extended active site consensus sequence HEXXHXXGXXHCX₄CXMX₁₇CXXC featuring four conserved cysteine residues. Very little is known about their biological importance and structure-function relationships.

Principal Findings

Here we present three crystal structures of the archaemetzincin AfAmzA (Uniprot {"type":"entrez-protein","attrs":{"text":"O29917","term_id":"74514303","term_text":"O29917"}}O29917) from Archaeoglobus fulgidus, revealing a metzincin architecture featuring a zinc finger-like structural element involving the conserved cysteines of the consensus motif. The active sites in all three structures are occluded to different extents rendering the enzymes proteolytically inactive against a large variety of tested substrates. Owing to the different ligand binding there are significant differences in active site architecture, revealing a large flexibility of the loops covering the active site cleft.

Conclusions

The crystal structures of AfAmzA provide the structural basis for the lack of activity in standard proteolytic assays and imply a triggered activity onset upon opening of the active site cleft.     

Lepadiform and scalpelliform barnacles from the Oligocene and Miocene of the Paratethys sea

Abstract: A review on the Oligocene and Miocene stalked barnacles of the Paratethys Sea is presented. The fauna comprises two lepadiform and eight scalpelliform species. Only two species are known from Oligocene deposits, four are documented from Lower Miocene formations, and another four species occur in the Middle Miocene. Only one Oligocene and one Miocene species occur in two different Paratethyan basins in roughly coeval environments, and only a single Middle Miocene species is also known from the adjacent Mediterranean Sea. This low degree of biogeographical similarity is probably a result from the still low number of publications dealing with this group. Stalked barnacles are often indicating bathyal or at least deep sublittoral environments. Especially, the abundance of the benthic deep‐water lepadiform Poecilasma in evaporitic deposits of the Middle Miocene Badenian Salinity Crisis may serve as new evidence for a deeper marine depositional environment. Scalpellum paratethyianum sp. nov. and Lepas sattmanni sp. nov. are described as new species; Arcoscalpellum renevieri (Mayer and Gümbel in Gümbel, 1861) is introduced as new combination.     

Seed characteristics and fatty acid composition of castor (<i>Ricinus communis</i> L.) varieties in Northeast China

Oil content and fatty acid composition were investigated on 12 castor varieties and strains by using the soxhlet extraction method and capillary gas chromatography. This was made to provide a reference and theoretical basis for castorbean breeding with high oil content, determine variability of seed compounds for breeding purposes, and broaden chemical material choices. Results revealed that crude fat percentage in seeds ranged from 18.91 to 35.84% with an average of 25.91%; the absolute content of ricinoleic acid varied between 171.65 g/kg and 314.03 g/kg with an average of 222.43 g/kg, and kernel crude fat percentage was between 24.28 and 46.97% with an average of 34.30%. All these study variables were highest in the 2129 strain. The percentage of ricinoleic acid in crude fat was between 83.85 to 87.62%, and the highest value was found in the zhebi4 accession. The other fatty acids appeared in small concentrations, and showed small amplitude: 1.12 to 1.61%, 1.21 to 1.61%, 3.53 to 4.80%, 5.35 to 6.38%, 0.52 to 0.79%, 0.05 to 0.08% and 0.43 to 0.55%, for palmitic, stearic, oleic, linolic, linolenic, arachidic, and arachidonic acids, respectively. One hundred seed weight was determined for each accession. One hundred seed weight ranged from 25.7 g to 34.0 g with an average of 29.9 g. There was a significant correlation between seed weight and oil content, but the correlation value was low (r=0.51). Cluster analysis by SSPS based on the content of fatty acid composition revealed that the accessions were divided into three independent clusters. These findings will clearly provide useful information for further research in breeding and utilization of castor oil.     

骨形成蛋白(BMP)-2/4，-5与IA型BMP受体在口腔正常上皮、良性病变及癌变中的表达分析

认识BMP及其受体与口腔正常上皮及其癌变的关系。有助于深入了解口腔上皮癌变的机理。本文用免疫组织化学方法对BMP-2/4,-5与BMPR-IA在口腔颊部粘膜正常上皮,良性病变和癌变中的表达进行观察和半定量分析。标本包括：9例正常上皮（normal buccal muosa,NB)。8例慢性炎症（nonspecific chronic inflammation,NCI),7例过度角化（hyperkeratosis,HK)。5例乳头状瘤（squamous cell papilloma,SCP)。29例鳞癌（squamous cell carcinoma,SCC)。10例癌旁上皮（epithelium immediately adjacent to carcinoma,EAC)以及6例硬腭粘膜上皮（normal mucosa of hard palate,NHP）。结果显示：BMP-2/4,-5与BMPR-IA在口腔粘膜的正常与良性病变上皮中有弱的和不均一的阳性表达,NB与NHP无明显差别,而除3例SCC外,其它SCC几乎均有程度不一的阳性表达,在EAC中的表达接近于SCC,二者明显高于正常与良性组,此外,转移在淋巴结中的癌细胞的BMP-2/4与BMP-5阳性程度略高于原发灶的癌细胞,本文认为;BMP-2/4,5与BMPR-IA可能参与调控口腔上皮的癌变。     

Signals transduced by Ca(2+)/calcineurin and NFATc3/c4 pattern the developing vasculature.

Vascular development requires an orderly exchange of signals between growing vessels and their supporting tissues, but little is known of the intracellular signaling pathways underlying this communication. We find that mice with disruptions of both NFATc4 and the related NFATc3 genes die around E11 with generalized defects in vessel assembly as well as excessive and disorganized growth of vessels into the neural tube and somites. Since calcineurin is thought to control nuclear localization of NFATc proteins, we introduced a mutation into the calcineurin B gene that prevents phosphatase activation by Ca(2+) signals. These CnB mutant mice exhibit vascular developmental abnormalities similar to the NFATc3/c4 null mice. We show that calcineurin function is transiently required between E7.5 and E8.5. Hence, early calcineurin/NFAT signaling initiates the later cross-talk between vessels and surrounding tissues that pattern the vasculature.     

Highly potent and selective alphaVbeta3-receptor antagonists: solid-phase synthesis and SAR of 1-substituted 4-amino-1H-pyrimidin-2-ones

Solid-phase synthesis and SAR of alpha(V)beta(3)-receptor antagonists based on a N(1)-substituted 4-amino-1H-pyrimidin-2-one scaffold are described. The most potent compounds exhibited IC(50) values towards alpha(V)beta(3) in the nano- to subnanomolar range and high selectivity versus related integrins like alpha(IIb)beta(3). For selected examples efficacy in functional cellular assays was demonstrated.