Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q9UIJ5 (Rec)
 58,342 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The morphology and development of junctional complexes between blastomeres of the preimplantation rabbit embryo were investigated using several approaches. Electron microscopic examination of embryos stained en bloc with uranyl acetate, and the study of junction permeability using horseradish peroxidase and lanthanum nitrate provided information on structure, intermembrane spacing and permeability of the junctional complexes. In addition, the freeze fracture technique was used with day 5 and day 6 blastocysts, since the large size of these embryos facilitated use of this method. These experiments showed that although rudimentary junctions were present between blastomeres of the early cleavage stages, effective tight junctions were not present until the blastocyst stage. Electron microscopic examination of thin sections revealed apical foci of membrane approximation or "fusion" between trophoblast cells by day 4. Freeze fracturing revealed a lattice of interconnecting ridges (on the A face) and grooves (on the B face) in the apical region between trophoblast cells of the day 5 blastocyst. This lattice formed a continuous band along the apical margin of each cell, and therefore constituted a zonula occludens. The zonula occludens of the day 5 blastocyst averages 2-3 ridges per lattice, while day 6 blastocysts had lattices that averaged 5-6 ridges. Also seen in the freeze fracture replicas from the day 5 and day 6 blastocysts were local accumulations of intramembranous particles on the A face. These particles were often observed in aggregates similar to those of previously described gap junctions. It could not be determined whether these small regions of particles were true gap junctions or a possible primitive form of gap junction because the complementary pitted surfaces (B face pits) were not demonstrated.
Anat Rec 1975 Jan
PMID:Junctional complexes in the preimplantation rabbit embryo. 4 78

Frog retinae, fixed only in buffered glutaraldehyde, were embedded for sectioning in glutaraldehyde polymerized with urea. In suitably thin sections globular substructures were seen in negative contrast after ionic staining with uranyl acetate and lead citrate, or after staining with neutralized phosphotungstic acid. Efforts to extract at least some of the lipid from sections before ionic staining enhanced the visualization of the "globules". Exposure to KMnO4 solution, used as an oxidative section stain, also outlined globular substructure in negative contrast, but with the additional feature that positively stained surface "leaflets" associated with the aqueous compartment were well defined. Staining sections with OSO4 vapor resulted in positively stained membranes, but without any evident substructure. However, when sections which previously had been exposed to OSO4 vapor were secondarily stained with uranyl acetate and/or lead citrate, positively stained globular substructures then were revealed. The globular substructures always were centered in the hydrophobic core region of the disc membranes, and symmetrically spanned the full thickness of this layer. The diameter of individual particles approximated 50-55 A. Reasons are presented for the supposition that the evident globules incorporate at least hydrophobic components of rhodopsin molecules. Findings are discussed in relation to various models of disc membrane organization that have been proposed in recent years.
Anat Rec 1975 May
PMID:Substructure in rod photoreceptor membranes. 5 Jul 51

The ultrastructure and permeability of the apical junctions between epithelial cells of the distal nephron have been studied in rat kidney using a collidal lanthanum tracer and uranyl acetate staining en bloc. The apical intercellular junctions of the macula densa and juxtaglomerular segment of the early distal convoluted tubule measure up to 0.5 mu in length and about 50 A in width. Lanthanum permeates the occluding portion of these junctions in a discontinuous manner, defining a series of closely spaced and parallel lines of fusion that run in a direction perpendicular to the apical-basal axis of the tubular cells. The apical junctions of the remainder of the distal convoluted and cortical collecting tubules are impermeable bolanthanum. This distinctive apical tight junction can account for the greater permeability to ions of the early distal convoluted vs. late distal convoluted and cortical collecting tubules.
Anat Rec 1976 Jun
PMID:Specialized junction in the distal convoluted tubule of rat kidney. 5 70

Intravenous administration of lead acetate to rabbits for 10 weeks at 2 week intervals resulted in significantly elevated blood lead levels, slight anemia with marked microspherocytosis and moderate basophilic stippling, and marked depression of red cell delta-aminolevulinic acid (ALA) dehydratase activity. However the decrease in red cell pyrimidine 5'-nucleotidase (P5N) activity was slight when compared to the red cell P5N activity of comparable reticulocyte-rich blood, and intracellular accumulation of pyrimidine nucleotides could not be demonstrated. In the in vitro inhibition test the same degree of inhibition of red cell P5N activity seen in hereditary red cell P5N deficiency was obtained by using a lead concentration 200--400 times higher than the lead levels detected in human plumbism. Most importantly, there were no differences in the lead-induced inhibition of human and rabbit red cell P5N. From the results of the in vitro inhibition test, lead-induced red cell P5N deficiency appears to be one of several pathogenic mechanisms in chronic lead exposure associated with the accumulation of lead in bone marrow. A decrease in rec cell P5N activity could not be demonstrated despite the marked depression in red cell ALA dehydratase activity, and slight anemia with marked microspherocytosis and moderate basophilic stippling in this experiment. These results suggest that lead affects red cells at multiple metabolic loci.
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PMID:A role of red cell pyrimidine 5'-nucleotidase in experimental lead poisoning. 23 20

Electron microscopic observations and measurements were made on thin-sectioned chromatin fibers and fibrils obtained from nuclei of mature chicken erythrocytes. The nuclei were isolated in low ionic strength gum arabic and octanol then extracted sequentially with (1) 0.14 M NaCl, (2) 0.25 N HCl, (3) buffer saturated phenol, (4) hot 5% SDS and 0.14 M 2-mercaptoethanol and, (5) 0.4 N NaOH. The amount of nuclear protein removed at each of the first four extraction steps was 1, 86, 3 and 11% of the total, respectively. Each extract was characterized by electrophoretic profiles. At each extraction the chromatin was fixed by adding large quantities of a mixture of equal volumes of sodium cacodylate buffered 8% (w/v) glutaraldehyde (pH 6.8) and 2% OsO4 (w/v), directly into (1) an aliquot of the chromatin in extraction fluid, and (2) an aliquot of the chromatin after water washing and swelling. Three size classes of chromatin structure were seen in thin sections prepared for high resolution transmission electron microscopy and stained with uranyl acetate and lead citrate. A thick fiber of about 25 + nm diameter was the predominant large fiber seen in freshly isolated nuclei or in nuclei after salt extraction. This 25 + nm fiber has a substructure consisting of 3.2-5.2 nm diameter fibrils. After water swelling of such freshly isolated or salt extracted nuclei a fiber of about 10 nm diameter was the predominant large fiber instead of the 25 nm diameter fiber. The HCl extraction step which is known to remove histones, caused the disappearance of both the 25 nm and the 10 nm fibers. High magnification (600,000 x) micrographs of the chromatin at all procedural steps, except the last NaOH step, reveal the fibril to be omnipresent. This fibril tends to decrease somewhat in diameter during the protein extraction steps to a 2.5 nm diameter fibril after the hot SDS extraction. A fibril of 2.5 nm diameter is expected of naked double helical DNA stained with a positive stain. The NaOH, which is known to denature DNA, completely destroyed the remaining fibril. We inerpret our results to indicate that the larger chromatin fiber seen in micrographs of thin-sectioned chromatin has a fibrillar substructure which probably represents a double coil of native DNA which may have a thin protein coating of its own. The latter fibril may in turn be wrapped around a hydrophobic histone domain, perhaps reflected in the 10 nm diameter fiber which is seen upon swelling of the chromatin. This 10 nm diameter fiber is thought to be further packaged by folding into the 25 + nm diameter chromatin fiber most frequently reported in thin sections of eukaryotic cell nuclei in situ.
Anat Rec 1979 Aug
PMID:Chromatin substructure: an electron microscopic study of thin-sectioned chromatin subjected to sequential protein extraction and water swelling procedures. 47 16

The relative effectiveness of implanting 300 mg trenbolone acetate alone or in combination with either 15, 30 or 45 mg hexoestrol was studied in three 90-day experiments using 64 Friesian steers. In experiment 1 hexoestrol was shown to improve live-weight gain and efficiency of feed conversion in steers implanted with trenbolone acetate. In experiments 2 and 3 trenbolone acetate in combination with 30 mg hexoestrol gave a better growth response than when combined with either 15 or 45 mg. However, in experiment 3 trenbolone acetate plus 15 mg hexoestrol was shown to improve live-weight gain by about 36 per cent compared with untreated controls. In experiment 2 small differences between treated groups in mean values for plasma urea, serum albumin, plasma glucose and free fatty acids were recorded.
Vet Rec 1979 Sep 22
PMID:Effect of hexoestrol on the response of finishing steers to treatment with trenbolone acetate. 51 14

Twenty British Friesian steers were divided into four uniform groups and either not treated or implanted with hexoestrol, trenbolone acetate, or hexoestrol plus trenbolone acetate. Hexoestrol was given 90 days and trenbolone acetate 70 days, before slaughter. Animals in the treatment groups grew significantly faster, converted food to live-weight gain more effciently faster, converted food to live-weight gain more efficiently and had lower levels of plasma urea and to a lesser extent serum albumin than untreated controls for the final 70 days before slaughter. The combined treatment of hexoestrol plus trenbolone acetate produced more pronounced effects than either compound given alone. Steers treated with hexoestrol had significantly greater levels of serum growth hormone than steers implanted with trenbolone acetate alone or untreated controls, but the treatments had no significant effect on levels of plasma glucose, free fatty acids or serum insulin. Carcase conformation and fat cover assessed subjectively did not differ between treated and control animals but killing out percentage was generally higher in all treatment groups.
Vet Rec 1978 Jul 08
PMID:Performance, blood and carcase characteristics of finishing steers treated with trenbolone acetate and hexoestrol. 68 99

Cell separation techniques and scanning electron microscopy (SEM) were used to characterize the surface morphology of small lymphocytes in mouse bone marrow. Lymphocyte-rich fractions and unfractionated suspensions of bone marrow and spleen cells from 9--10-week-old C3H male mice were glutaraldehyde-fixed, syringed onto gelatin-coated silver membranes, dehydrated in ethanol, infiltrated with amyl acetate, critical point dried, coated with gold-palladium and examined by SEM. High proportions of cells were retained on the membranes. Purified spleen small lymphocytes showed unimodal distribution curves for cell diameter (mode, 3.4 micrometer) and for number of surface microvilli (mode, 55--60). Bone marrow small lymphocytes were identified initially in lymphocyte-rich marrow fractions and in erythroblast-depleted marrow from polycythemic mice as well as in normal whole marrow. The cells resembled spleen small lymphocytes in size distribution and they showed microvilli. However, the number of visible microvilli was lower on small lymphocytes in the bone marrow (mode, 35--40) than in the spleen. While in each small lymphocyte population the total number of microvilli was greater on larger cells than on smaller ones, the density of microvilli per unit area of cell surface tended to decrease with increasing cell size. The results establish that the small lymphocytes in mouse bone marrow, mainly locally-produced immature cells, have villous surfaces, but the number of microvilli per unit cell surface area is less than that on peripheral small lymphocytes, as seen in the spleen. Neither in the bone marrow nor in the spleen are subpopulations of small lymphocytes distinguishable solely by numbers of microvilli. The findings suggest that microvilli on bone marrow small lymphocytes may undergo further development during post-mitotic maturation, surface receptor expression and migration of the cells to peripheral lymphoid tissues.
Anat Rec 1978 Nov
PMID:Surface morphology of bone marrow lymphocytes. I. Scanning electron microscopy of small lymphocytes bone marrow and spleen. 72 27

The octane plasmid (OCT) in Pseudomonas putida strains has been shown to be transferred at low frequency. However, bacteria which had newly received this plasmid showed a transient increase in donor ability. Using Octane+ P. putida as the donor, the transfer of most chromosomal markers was shown to be independent of OCT transfer, whereas the mobilization of the octanoate catabolism genes (octanoic and acetate) was dependent on OCT plasmid transfer. The presence of a fertility factor termed FPo has been postulated to explain these results. Strains carrying only this fertility factor have been obtained from strains carrying both OCT and FPo plasmids. Strains in which the OCT plasmid was transferred at high frequencies have also been isolated, and chromosome mobilization by OCT and FPo has been compared. A different gradient of transmission by OCT and FPo has been observed. It has also been shown that chromosome transfer by OCT was dependent on the bacterial recombination system, whereas the chromosome transfer by FPo was unaffected by the presence of a rec mutation in the donor strain.
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PMID:Fertility factors in Pseudomonas putida: selection and properties of high-frequency transfer and chromosome donors. 76 14

The occurrence of atrophic changes in veterinary animals following the sc administration of cystalline medroxyprogesterone acetate (MPA) is reported. 2 daschunds who had been injected sc with MPA developed thinning of the skin, discoloration of the hair, and mobilization of subcutaneous fat. These changes were probably due to the antiinflammatory nature of the drug. Such effects do not occur with the im administration of MPA.
Vet Rec 1977 Jan 22
PMID:After-effect of injection. 83 19


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