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M L Bauer D L Harmon K R McLeod G B Huntington 《Comparative biochemistry and physiology. Part A, Molecular & integrative physiology》2001,129(2-3):577-583
Eight steers and 12 lambs were used in a completely randomized experimental design to determine the effect of partial alpha-amylase starch hydrolysate (SH) on small intestinal sodium-dependent glucose transport activity. Starch hydrolysate was delivered ruminally or abomasally to steers (960 g/day) and sheep (144 g/day) for 7 days. On day 7, the steers were rendered unconscious, exsanguinated and eviscerated. A 1-m section of jejunum was collected starting at the duodenojejunal flexure. Sheep were anaesthetized with pentobarbital and the second meter of small intestine (jejunum) was collected. Brush-border membrane vesicles were prepared and sodium-dependent glucose uptake activity was measured using the rapid uptake/filtration technique. Alkaline phosphatase and maltase activity was enriched by 8.2+/-0.5- and 8.4+/-1.2-fold in the vesicle preparation, respectively, and was not different between treatments. Abomasal SH increased (P=0.03) the Na/glucose co-transport approximately two-fold in both cattle (47.2-114.0+/-31.5 pmol/mgxsec) and sheep (77.4-152.0+/-25.7 pmol mg(-1) s(-1)). We conclude that Na/glucose co-transport activity by enterocytes responds to luminal alpha-linked glucose (from abomasal infusion) in ruminants, compared with controls. Intestinal maltase-specific activity does not respond to alpha-linked glucose in cattle, and decreases slightly in sheep. 相似文献
4.
The human alpha satellite repetitive DNA family is organized as distinct chromosomal subsets located at the centromeric regions of each human chromosome. Here, we describe a subset of the alpha satellite which is localized to human chromosome 11. The principal unit of repetition of this alpha satellite subset is an 850 bp XbaI fragment composed of five tandem diverged alphoid monomers, each 171 bp in length. The pentamer repeat units are themselves tandemly reiterated, present in 500 copies per chromosome 11. In filter hybridization experiments, the Alpha 11 probes are specific for the centromeric alpha satellite sequences of human chromosome 11. The complete nucleotide sequences of two independent copies of the XbaI pentamer reveal a pentameric configuration shared with the alphoid repeats of chromosomes 17 and X, consistent with the existence of an ancestral pentameric repeat common to the centromeric arrays of at least these three human chromosomes. 相似文献
5.
Infection was studied in mice with varying doses of spherule-endospore phase cultures of Coccidioides immitis, administered intraperitoneally, intravenously and intranasally. Stain 46 was compared with strain Silveira. The first of these is relatively avirulent in the mycelial phase, the second, rather virulent. Animals were observed for acute death and for circling. Gross and microscopic pathology was studied in mice sacrificed at appropriate intervals after infection. Numbers of fungi were assayed in spleen, lung, kidney, liver, blood, brain, and ear tissue. Strain 46 endospores administered intraperitoneally in doses from 9 × 106 to 2.5 × 107 produced a high incidence of circling syndrome ataxia attributable to inner ear disease. 相似文献
6.
The effects of the trichothecene mycotoxins (acetyl T-2 toxin, T-2 toxin, HT-2 toxin, palmityl T-2 toxin, diacetoxyscirpenol (DAS), deoxynivalenol (DON), and T-2 tetraol) on bovine platelet function were examined in homologous plasma stimulated with platelet activating factor (PAF). The mycotoxins inhibited platelet function with the following order of potency: acetyl T-2 toxin > palmityl T-2 toxin = DAS > HT-2 toxin = T-2 toxin. While T-2 tetraol was completely ineffective as an inhibitor, DON exhibited minimal inhibitory activity at concentrations above 10×10?4M. The stability of the platelet aggregates formed was significantly reduced in all mycotoxin treated platelets compared to that of the untreated PAF controls. It is suggested that the increased sensitivity of PAF stimulated bovine platelets to the more lipophilic mycotoxins may be related to their more efficient partitioning into the platelet membrane compared to the more hydrophilic compounds. 相似文献
7.
Hrushikesh S. Chaudhari Omkar S. Palkar KM Abha Mishra Kalyan K. Sethi 《Journal of biochemical and molecular toxicology》2023,37(9):e23417
During the period of COVID-19, the occurrences of mucormycosis in immunocompromised patients have increased significantly. Mucormycosis (black fungus) is a rare and rapidly progressing fungal infection associated with high mortality and morbidity in India as well as globally. The causative agents for this infection are collectively called mucoromycetes which are the members of the order Mucorales. The diagnosis of the infection needs to be performed as soon as the occurrence of clinical symptoms which differs with types of Mucorales infection. Imaging techniques magnetic resonance imaging or computed tomography scan, culture testing, and microscopy are the approaches for the diagnosis. After the diagnosis of the infection is confirmed, rapid action is needed for the treatment in the form of antifungal therapy or surgery depending upon the severity of the infection. Delaying in treatment declines the chances of survival. In antifungal therapy, there are two approaches first-line therapy (monotherapy) and combination therapy. Amphotericin B ( 1 ) and isavuconazole ( 2 ) are the drugs of choice for first-line therapy in the treatment of mucormycosis. Salvage therapy with posaconazole ( 3 ) and deferasirox ( 4 ) is another approach for patients who are not responsible for any other therapy. Adjunctive therapy is also used in the treatment of mucormycosis along with first-line therapy, which involves hyperbaric oxygen and cytokine therapy. There are some drugs like VT-1161 ( 5 ) and APX001A ( 6 ), Colistin, SCH 42427, and PC1244 that are under clinical trials. Despite all these approaches, none can be 100% successful in giving results. Therefore, new medications with favorable or little side effects are required for the treatment of mucormycosis. 相似文献
8.
Normal rabbit ear cartilage studied with the light and electron microscope shows chondrocytes in which large lipide spherules, and an abundance of glycogen, a few small mitochondria, and relatively few elements of the endoplasmic reticulum can be identified. The chondrocytes contain, in addition, a material which stains strongly with acid fuchsin and appears in the electron microscope as a relatively dense felt-work. In electron micrographs, the matrix of normal rabbit ear cartilage consists of two components: a uniformly distributed moderately dense substance which appears as a fine meshwork without any particular pattern extending from cartilage cell border to cartilage cell border; and a three-dimensional anastomotic network of more dense material, which is best described as "felt-like" lying between the cells. The similarity between the felt-like material of the matrix and the elastic fibers described in previous electron microscope observations is discussed. 相似文献
9.
Huntington F. Willard 《Chromosoma》1977,61(1):61-73
Regional DNA replication kinetics in human X chromosomes have been analysed using BrdU-33258 Hoechst-Giemsa techniques in five cell types from human females: amniotic fluid cells, fetal and adult skin fibroblasts, and fetal and adult peripheral lymphocytes. In all cell types, the late-replicating X chromosome can be distinguished from its active, earlyreplicating homologue, and both the early and late X exhibit temporally and regionally characteristic internal sequences of DNA replication. The replication pattern of the early X in amniotic fluid cells and skin fibroblasts is similar to that of the early X in lymphocytes, although certain discrete regions are later-replicating in these monolayer tissue culture cells than are the corresponding regions in lymphocytes. However, DNA replication kinetics in late X chromosomes from amniotic fluid cells and skin fibroblasts are strikingly different from those observed in lymphocytes with respect both to the initiation and termination of DNA synthesis. The predominant late X pattern observed in 80–95% of lymphocytes, in which replication terminates in the long arm in bands Xq21 and Xq23, was never seen in amniotic fluid cells or skin fibroblasts. Instead, in these cell types, bands Xq25 and Xq27 are the last to complete DNA synthesis, while bands Xq21 and Xq23 are earlier-replicating; this pattern is similar to the alternative replication sequence observed in 5–20% of lymphocyte late X chromosomes. This replication sequence heterogeneity is consistent with the existence of tissue-specific influences on the control of DNA replication in human X chromosomes. 相似文献
10.
Evolution of alpha satellite 总被引:13,自引:0,他引:13
Huntington F. Willard 《Current opinion in genetics & development》1991,1(4):509-514
Alpha satellite is one of the most thoroughly studied repetitive DNA families and is a paradigm for understanding other satellite DNA and multigene families. Alpha satellite illustrates both intra- and interchromosomal modes of evolution. Recent advances in understanding the structure and evolution of human and other primate alpha satellites are summarized in this review. 相似文献