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71.
Porcine follicular fluid (PFF) contains a factor (inhibin or folliculostatin) which is reported to selectively inhibit the secretion of follicle-stimulating hormone (FSH) from the anterior pituitary gland. Chronic treatment of hemicastrate immature rats with PFF is able to partially inhibit the FSH-mediated hypertrophy of the remaining testis. However, the pituitaries from PFF-treated rats are paradoxically very sensitive to stimulation with gonadotrophin-releasing hormone (GnRH) and secrete significantly more FSH than control glands. Furthermore, this increased sensitivity results in a large increase in luteinizing hormone (LH) secretion. These observations suggest that under certain circumstances PFF is not selective for FSH and that it surprisingly stimulates rather than inhibits gonadotrophin secretion.  相似文献   
72.
About 650 zooplankton samples were collected from Lake Inarijärvi in 1977–1979 from the littoral and pelagial zones of the lake. One hundred and twenty-three zooplankton taxa were found and most of them can be considered euplanktonic.The most important species were Holopedium gibberum, Daphnia cristata, Cyclops spp. and Eudiaptomus spp. Mean pelagial zooplankton biomass was 0.29 g m–3 in the 0–5 m depth zone, 0.17 g m–3 in 5–10 m and 0.11 g m–3 in 10–20 m.The zooplankton biomass at a sandy shore was about 0.09 g m–3, at a stony shore 0.05 g m–3 and at a vegetated shore 0.76 g m–3. About 70% of the whole zooplankton production consisted of crustaceans.The sum of herbivore and carnivore zooplankton production in the pelagial area during the summer was 210–330 kg ha–1 × 3 months.  相似文献   
73.
Peng Y  Ang M  Foo S  Lee WS  Ma Z  Venkatraman SS  Wong TT 《PloS one》2011,6(7):e22507
Sustained ocular drug delivery is difficult to achieve. Most drugs have poor penetration due to the multiple physiological barriers of the eye and are rapidly cleared if applied topically. Biodegradable subconjunctival implants with controlled drug release may circumvent these two problems. In our study, two microfilms (poly [d,l-lactide-co-glycolide] PLGA and poly[d,l-lactide-co-caprolactone] PLC were developed and evaluated for their degradation behavior in vitro and in vivo. We also evaluated the biocompatibility of both microfilms. Eighteen eyes (9 rabbits) were surgically implanted with one type of microfilm in each eye. Serial anterior-segment optical coherence tomography (AS-OCT) scans together with serial slit-lamp microscopy allowed us to measure thickness and cross-sectional area of the microfilms. In vitro studies revealed bulk degradation kinetics for both microfilms, while in vivo studies demonstrated surface erosion kinetics. Serial slit-lamp microscopy revealed no significant inflammation or vascularization in both types of implants (mean increase in vascularity grade PLGA50/50 12±0.5% vs. PLC70/30 15±0.6%; P?=?0.91) over a period of 6 months. Histology, immunohistochemistry and immuno-fluorescence also revealed no significant inflammatory reaction from either of the microfilms, which confirmed that both microfilms are biocompatible. The duration of the drug delivery can be tailored by selecting the materials, which have different degradation kinetics, to suit the desired clinical therapeutic application.  相似文献   
74.
Infections with the bacteria Burkholderia cepacia complex (Bcc) are very difficult to eradicate in cystic fibrosis patients due the intrinsic resistance of Bcc to most available antibiotics and the emergence of multiple antibiotic resistant strains during antibiotic treatment. In this work, we used a whole-cell based assay to screen a diverse collection of small molecules for growth inhibitors of a relevant strain of Bcc, B. cenocepacia K56-2. The primary screen used bacterial growth in 96-well plate format and identified 206 primary actives among 30,259 compounds. From 100 compounds with no previous record of antibacterial activity secondary screening and data mining selected a total of Bce bioactives that were further analyzed. An experimental pipeline, evaluating in vitro antibacterial and antibiofilm activity, toxicity and in vivo antibacterial activity using C. elegans was used for prioritizing compounds with better chances to be further investigated as potential Bcc antibacterial drugs. This high throughput screen, along with the in vitro and in vivo analysis highlights the utility of this experimental method to quickly identify bioactives as a starting point of antibacterial drug discovery.  相似文献   
75.
The features of ontogenetic variation in the shell shape of the bivalve Mytilus trossulus were studied based on material that was collected from different biotopes in the Vostok Bay of the Sea of Japan in 2011. It was revealed that the mollusks had different shell shapes in rock populations and in foulings of artificial substrates but all the developmental changes fall within formerly recorded peculiarities. It is shown that significant deviations from the typical form of the shell are characteristic to mollusks from the fouling of thalli of the brown algae Sargassum pallidum that inhabit shallow water at surf-exposed rocky headlands. The mollusks from this biotope were characterized by numerous traces of deformations of the shell, an atypically skewed growth of the rear edge, and a significant excess (20–25%) of the width over the shell height. It was revealed that the recorded features of shell morphology are apparently associated with features of mussel habitation in an environment with active hydrodynamics.  相似文献   
76.
Molecular Biology Reports - Analysis of the reactive oxygen species (ROS)-detoxifying biomarkers may elucidate the mitochondrial dysfunction in glaucoma pathogenesis. Therefore, we purposed to...  相似文献   
77.
The distribution and growth of the bivalve mollusk Protothaca euglypta in Peter the Great Bay and at the northern boundary of its area were investigated. It is shown that in some biotopes P. euglypta biomass reaches 1–2 kg/m2, which exceeds the estimated values of abundance obtained for most associated species of mollusks. It has been established that local variability of P. euglypta growth rates can be compared with latitudinal variability, and the life span increases from the southern part of the area towards its northern boundary. It has been concluded that P. euglypta occupies a more prominent position in the malacofauna of shallow waters in its abundance, than it was considered earlier.  相似文献   
78.
79.
Memory T cells cross-reactive with epitopes encoded by related or even unrelated viruses may alter the immune response and pathogenesis of infection by a process known as heterologous immunity. Because a challenge virus epitope may react with only a subset of the T cell repertoire in a cross-reactive epitope-specific memory pool, the vigorous cross-reactive response may be narrowly focused, or oligoclonal. We show in this article, by examining human T cell cross-reactivity between the HLA-A2-restricted influenza A virus-encoded M1(58-66) epitope (GILGFVFTL) and the dissimilar Epstein-Barr virus-encoded BMLF1(280-288) epitope (GLCTLVAML), that, under some conditions, heterologous immunity can lead to a significant broadening, rather than a narrowing, of the TCR repertoire. We suggest that dissimilar cross-reactive epitopes might generate a broad, rather than a narrow, T cell repertoire if there is a lack of dominant high-affinity clones; this hypothesis is supported by computer simulation.  相似文献   
80.
The investigation into the potential usefulness of phytoestrogens in the treatment of menopausal symptoms requires large-scale clinical trials that involve rapid, validated assays for the characterization and quantification of the phytoestrogenic precursors and their metabolites in biological matrices, as large interindividual differences in metabolism and bioavailability have been reported. Consequently, a new sensitive high-performance liquid chromatography-mass spectrometry method (HPLC–MS) for the quantitative determination of thirteen phytoestrogens including their most important gut microbial metabolites (genistein, daidzein, equol, dihydrodaidzein, O-desmethylangolensin, coumestrol, secoisolariciresinol, matairesinol, enterodiol, enterolactone, isoxanthohumol, xanthohumol and 8-prenylnaringenin) in human urine and serum within one single analytical run was developed. The method uses a simple sample preparation procedure consisting of enzymatic deconjugation followed by liquid–liquid extraction (LLE) or solid-phase extraction (SPE) for urine or serum, respectively. The phytoestrogens and their metabolites are detected with a single quadrupole mass spectrometer using atmospheric pressure chemical ionization (APCI), operating both in the positive and the negative mode. This bioanalytical method has been fully validated and proved to allow an accurate and precise quantification of the targeted phytoestrogens and their metabolites covering the lower parts-per-billion range for the measurement of relevant urine and serum levels following ingestion of phytoestrogen-rich dietary supplements.  相似文献   
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