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91.
The influence of diabetes on the enzyme hexokinase (HK) was examined in the salivary glands of rats. Diabetes was induced by an intraperitoneal injection of streptozotocin (60 mg/Kg body weight) in overnight fasted rats (180-200 g). The animals were killed 48 hours and 30 days after the induction of diabetes and the submandibular and parotid salivary glands extracted for use. Hyperglycemia was evaluated by determining the blood sugar. The area occupied by each intralobular component, acini, ducts, total parenchyma and stroma was measured, and no differences were observed compared with control. In the soluble fraction of the submandibular gland, no difference in the specific activity of HK was observed, between the diabetic and control animals, however, the activity per gland and per g of tissue showed lower values than control. The specific activity of the bound form was reduced in the diabetic gland. The results obtained for the parotid gland were different from the submandibular. The specific activity of both the soluble and bound forms were increased in the diabetic animals. The DEAE-cellulose column chromatography of the soluble and bound forms of the enzyme from both glands showed a first peak appearing during the washing of the column and two other peaks were eluted by the gradient. Thus, three isoenzymes in the submandibular and parotid salivary glands for the control and diabetic rats have been found. 相似文献
92.
Martinez-Neira R Kekic M Nicolau D dos Remedios CG 《Biosensors & bioelectronics》2005,20(7):1428-1432
We explored the potential of contractile proteins, actin and myosin, as biosensors of solutions containing mercuric ions. We demonstrate that the reaction of HgCl2 with myosin rapidly inhibits actin-activated myosin ATPase activity. Mercuric ions inhibit the in vitro analog of contraction, namely the ATP-initiated superprecipitation of the reconstituted actomyosin complex. Hg reduces both the rate and extent of this reaction. Direct observation of the propulsive movement of actin filaments (10 nm in diameter and 1 microm long) in a motility assay driven by a proteolytic fragment of myosin (heavy meromyosin or HMM) is also inhibited by mercuric ions. Thus, we have demonstrated the biochemical, biophysical and nanotechnological basis of what may prove to be a useful nano-device. 相似文献
93.
Low-Molecular-Weight,Biologically Active Compounds from Marine <Emphasis Type="Italic">Pseudoalteromonas</Emphasis> Species 总被引:2,自引:0,他引:2
Kalinovskaya NI Ivanova EP Alexeeva YV Gorshkova NM Kuznetsova TA Dmitrenok AS Nicolau DV 《Current microbiology》2004,48(6):441-446
We have examined the ability of marine Proteobacteria from the Pseudoalteromonas genus and Alteromonas macleodii to produce low-molecular-weight, biologically active compounds with antimicrobial and surface-active properties. A new marine bacterium, Pseudoalteromonas issachenkonii, exhibited a high level of biological activity and produced antifungal and hemolytic compounds. A detailed spectroscopic investigation based on UV, IR, high-resolution mass spectrometry, and 2D 1H and 13C nuclear magnetic resonance revealed that the former was indole-2,3-dione (isatin). The chemical structure of red-brown pigment (C9H7N3OS3) responsible for hemolytic activity remained unclear. Four of the 15 strains studied (P. luteoviolacea, P. rubra, P. undina, and P. issachenkonii) produced cell-bound, two (P. elaykovii and P. carrageenovora) produced extracellular, and one strain (P. citrea) produced cell-bound and extracellular fatty acids and phospholipids with surface activity. Neither peptides nor glycolipids with surface activity were detected. 相似文献
94.
V?Srinivasan GJM?Maestroni DP?Cardinali AI?Esquifino SR?Pandi?Perumal SC?MillerEmail author 《Immunity & ageing : I & A》2005,2(1):17
Aging is associated with a decline in immune function (immunosenescence), a situation known to correlate with increased incidence
of cancer, infectious and degenerative diseases. Innate, cellular and humoral immunity all exhibit increased deterioration
with age. A decrease in functional competence of individual natural killer (NK) cells is found with advancing age. Macrophages
and granulocytes show functional decline in aging as evidenced by their diminished phagocytic activity and impairment of superoxide
generation. There is also marked shift in cytokine profile as age advances, e.g., CD3+ and CD4+ cells decline in number whereas
CD8+ cells increase in elderly individuals. A decline in organ specific antibodies occurs causing reduced humoral responsiveness.
Circulating melatonin decreases with age and in recent years much interest has been focused on its immunomodulatory effect.
Melatonin stimulates the production of progenitor cells for granulocytes-macrophages. It also stimulates the production of
NK cells and CD4+ cells and inhibits CD8+ cells. The production and release of various cytokines from NK cells and T-helper
lymphocytes also are enhanced by melatonin. Melatonin presumably regulates immune function by acting on the immune-opioid
network, by affecting G protein-cAMP signal pathway and by regulating intracellular glutathione levels. Melatonin has the
potential therapeutic value to enhance immune function in aged individuals and in patients in an immunocompromised state. 相似文献
95.
Complement fixation test has a diagnostic value only when it is positive and specific. In some mycetomas caused byM. apiospermum andC. falciforme the diagnosis could be made a few days earlier before the identification of the causative agent by culture. In cases produced by opportunistic organisms such asA. fumigatus, S. albus, C. falciforme, the specific serological tests together with the repeated isolation of the fungus in culture, constituted the evidence in favor of the validity of the isolate.
Zusammenfassung Die Komplementfixierung hat einen diagnostischen Wert nur in dem Falle, wenn sie positiv und spezifisch ist. In manchen Mycetomen, verursacht durchM. apiospermum undC. falciforme konnte die Diagnose etliche Tage früher gemacht worden vor der Identifizierung des Pilzes durch Kultur. In den durch opportunistische Organismen verursachten Fällen, z. B. durchA. fumigatus, S. albus, C. falciforme lieferte der spezifische serologische Test in Zusammenhang mit der wiederholten Isolierung des Pilzes den Beweis für die Erregernatur des durch Kultur isolierten Pilzes.相似文献
96.
Low‐power laser irradiation decreases lipid droplet accumulation in the parotid glands of diabetic rats
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Juliana R. de Castro Eugen M. N. de Souza Yun‐Jong Park Luana de Campos Seunghee Cha Victor E. Arana‐Chavez José Nicolau Alyne Simões 《Journal of biophotonics》2018,11(4)
Lipid droplet accumulation has been related to salivary gland hypofunction in diabetes. In this study, the effect of laser irradiation on the parotid glands (PGs) of diabetic rats was analyzed with regard to its effect on lipid droplet accumulation, intracellular calcium concentration and calmodulin expression. The animals were distributed into 6 groups: D0, D5, D20 and C0, C5, C20, for diabetic (D) and control animals (C), respectively. Twenty‐nine days following diabetes induction, PGs of groups D5 and C5; D20 and C20 were irradiated with 5 and 20 J/cm2 of a red diode laser at 100 mW, respectively. After 24 hours, PGs were removed for histological, biochemical, and western blotting analysis. The diabetic animals showed lipid droplet accumulation, which was decreased after irradiation. Ultrastructurally, the droplets were nonmembrane bound and appeared irregularly located in the cytoplasm. Moreover, diabetic animals showed an increased intracellular calcium concentration. In contrast, after laser irradiation a progressive decrease in the concentration of this ion was observed, which would be in agreement with the results found in the increased expression of calmodulin in D20. These data are promising for using laser to decrease lipid droplet accumulation in PGs, however, more studies are necessary to better understand its mechanisms. Micrographs showing decreased lipid accumulation after laser irradiation in light micrographs (LM), and morphology of lipid droplet in transmission electron microscopic (TEM). LM: (A) PGs from nondiabetic rats that did not receive Laser irradiation (LI), (B) PGs from nondiabetic rats that received a dose of 20 J/cm2, (C) lipid accumulation (arrows) in the secretory cells from diabetic rats that did not receive irradiation, (D) reduction of lipid accumulation in the secretory cells from diabetic rats that received a dose of 20 J/cm2 and TEM: (E) scale bar = 5 μm, (F) scale bar = 1 μm, and (G) scale bar = 0.5 μm. 相似文献
97.
Evolution of the WANCY region in amniote mitochondrial DNA 总被引:7,自引:1,他引:6
In most vertebrate mitochondrial genomes, the site for initiation of
light-strand replication, OL, is found within a cluster of five transfer
RNA (tRNA) genes (tRNA(Trp), tRNA(Ala), tRNA(Asn), tRNA(Cys), and
tRNA(Tyr)). This region and part of the adjacent cytochrome c oxydase
subunit I (COI) gene were sequenced for two crocodilian, two turtle, and
one snake species and for Sphenodon punctatus; part of the adjacent
nicotinamide adenine dinucleotide dehydrogenase subunit 2 (ND2) gene was
also sequenced for the crocodilian and turtle species. All had the typical
vertebrate gene order. The turtles and the snake have a lengthy noncoding
sequence between the tRNA(Asn) and tRNA(Cys) genes that we assumed to be
homologous to the mammalian OL. The crocodilians and Sphenodon lack such a
sequence, a condition they share with birds. Most proposed phylogenies for
the amniotes require that OL at this position was lost at least twice
during their diversification or was evolved independently more than once.
Within the five tRNA genes, frequencies of substitutions are much higher in
loops than in stems. Many loops vary dramatically in size among the
species; in the most extreme case, the D-arm of the Sphenodon tRNA(Cys) is
a "D-arm replacement" loop of seven nucleotides. Frequency of transitions
in stems is relatively uniform across tRNAs, but frequency of transversions
varies greatly. Mismatches in stems are infrequent, and their relative
frequency in a specific tRNA is unrelated to the frequency of substitution
in the corresponding gene. Several features of mammalian mitochondrial
tRNAs are conserved in WANCY tRNAs throughout amniotes. The inferred
initiation codon for COI is GTG in crocodilians, turtles, and the snake, a
condition they share with fishes, certain amphibians, and birds. TTG
appears to be the initiation codon for COI in Sphenodon; if correct, this
would be a novel initiation codon for vertebrate mitochondrial DNA.
Phylogenetic analyses of the inferred amino acid sequences of ND2 and COI
support the sister-group relationship of birds and crocodilians and suggest
that mammals are an early derived lineage within the amniotes.
相似文献
98.
Mano Mario Cezar Rodrigues Neri-Numa Iramaia Angélica da Silva Juliana Bueno Paulino Bruno Nicolau Pessoa Marina Gabriel Pastore Gláucia Maria 《Applied microbiology and biotechnology》2018,102(1):17-37
Applied Microbiology and Biotechnology - Oligosaccharides are polymers with two to ten monosaccharide residues which have sweetener functions and sensory characteristics, in addition to exerting... 相似文献
99.
Untargeted liposomes (composition: PC-PS-cholesterol) and targeted liposomes (composition: PC-PS-cholesterol-lactosylceramide) having encapsulated concentration-quenched carboxyfluorescein were injected intravenously into mice. 1 h after injection, the mice livers were perfused, excised and the hepatocytes were separated from nonparenchymal cells and analysed in a fluorescence-activated cell sorter analyzer. The result was that hepatocytes took up significantly more liposomes when lactosylceramide was inserted in the liposome bilayers, which was in good agreement with observations made on the in vivo uptake of liposome-encapsulated insulin gene (Soriano, P. et al. (1983) Proc. Natl. Acad. Sci. USA, 80, 7128-7133). Cytofluorimetric analysis of the spleen cells showed that approx. 10% of the splenic lymphocytes take up high amounts of lactosylceramide liposomes, whereas most of the phospholipid liposomes are taken up by the phagocytic cells. The flow cytofluorimetric analysis shows, moreover, the internalization of the liposomes by the target cells and allows a quantitation of this uptake. Thus, in vivo targeting of the liposomes to specific liver and splenic cells, by means of glycolipid insertion in the liposome bilayer, is shown to take place with delivery of the liposomal aqueous space marker to these cells. 相似文献
100.