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31.
Administration of morphine to ten suckled and nine zero-weaned (piglets removed immediately after farrowing) sows was used to investigate the apparent absence of opioid regulation of LH and prolactin secretion in early lactation. Blood samples were collected at 10 min intervals at 24-30, 48-54, 72-78 h post partum, and for a 12 h period from 08:00 to 20:00 on day 10 after farrowing. Morphine (0.1 mg kg-1) was administered as three i.v. bolus injections at intervals of 1 h during the last 3 h of each of the 6 h sampling periods, and at 6, 7 and 8 h after the beginning of sampling on day 10. There were significant (P < 0.001) group (zero-weaned versus suckled), time and morphine effects on LH secretion. Plasma LH concentrations increased (P < 0.001) within 48 h of farrowing in zero-weaned sows. Long-term trends of an increase in mean plasma LH in the sampling periods before treatment were attenuated in both groups by morphine treatment. Morphine also significantly inhibited (P < 0.05) prolactin secretion in suckled sows. In zero-weaned sows, plasma prolactin was already low at the start of sampling and did not change with time or in response to morphine treatment. Therefore, the inability to demonstrate an opioidergic involvement in the suckling-induced inhibition of LH secretion during the early post-partum period in sows is not due to a lack of opioid receptors. Furthermore, in suckled sows, morphine is stimulatory to systems that have an inhibitory effect on prolactin secretion.  相似文献   
32.
Sarcoptic mange is a cause of pruritic skin disease in domestic dogs and a wide range of wildlife species. We describe sarcoptic mange in free-ranging raccoons (Procyon lotor). Three adult raccoons from upper Wayne County, Michigan (USA), were captured, killed, and submitted for diagnostic evaluation. The animals were intensely pruritic, and two had advanced alopecic and crusting lesions over their dorsum and hind limbs. Skin scrapings and skin biopsies revealed crusting and hyperkeratotic dermatitis with high numbers of Sarcoptes scabiei adults, larvae, nymphs, and eggs. These raccoons were not otherwise debilitated, with minimal internal parasites, good body condition, and no evidence of infectious bacterial or viral diseases. Because sarcoptic mange is highly contagious and affects many species, including humans, transiently, it is important that wildlife biologists and rehabilitators include sarcoptic mange in their differential list for raccoons exhibiting pruritus and alopecia.  相似文献   
33.
Halieutopsis bathyoreos Bradbury, 1988 (Lophiiformes: Ogcocephalidae), previously described only on the basis of the holotype (62.6mm in standard length) from the central North Pacific, is redescribed on the basis of the holotype and six additional specimens (41.2–68.7mm in standard length) collected from the western South Pacific, off Papua New Guinea, and the western North Pacific, including the Japanese Archipelago. Halieutopsis bathyoreos is distinguished from its congeners by having a shelflike rostrum extending anteriorly well beyond the mouth, a dorsal escal lobe slightly bisected ventrally, an illicial cavity square in outline and completely visible in ventral view, and lacking tubercles on the ventral surface of the disk. The following characters are newly added to the diagnoses of this species: rostrum width 21–29% of head length, tubercles on the dorsal surface of the disk about half the diameter of those on the lateral margin, and 13–15 large lateral-line scales on the tail.  相似文献   
34.
The purpose of this research was to improve the solubility and therefore dissolution and bioavailability of triamterene, a poorly water soluble diuretic, by complexation with β-cyclodextrin. Triamterene has been reported to show low bioavailability after oral administration, with wide intersubject variation. This study presents the formulation of solid dispersions of triamterene with β-cyclodextrin—by cogrinding, kneading, and coevaporation, using low pH conditions—and their characterizations, evaluation of improvement in dissolution profiles, and in vivo advantage. Phase solubility studies indicated complex with possible stoichiometry of 1∶1 and a stability constant of 167.67M−1. The solid dispersions were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance, x-ray diffraction, and differential scanning calorimetry studies. The characterization studies confirmed inclusion of the phenyl ring of triamterene within the nonpolar cavity of β-cyclodextrin in the coevaporate. Remarkable improvement in in vitro drug release profiles in 0.1 N HCl and pH 6.8 phosphate buffer was observed with all dispersions, especially the coevaporate. The coevaporate, when administered orally in rats, also exhibited improved in vivo activity, as measured by net sodium ion excretion, as compared with triamterene powder. Thus, coevaporation of the drug and β-cyclodextrin from acidified alcohol provide the optimum condition for inclusion complexation to give a binary system with remarkable improvement in in vitro drug release profile and in vivo performance.  相似文献   
35.
There are about 2.5 million glomeruli in the kidneys each consisting of a barrel of glomerular basement membrane surrounded by glomerular endothelial cells on the inside and glomerular epithelial cells with established foot processes (podocytes) on the outside. Defects in this filtration apparatus lead to glomerular vascular leak or proteinuria. The role of vascular endothelial growth factor (VEGF) in the regulation of glomerular vascular permeability is still unclear. Recent studies indicate that patients receiving anti-VEGF antibody therapy may have an increased incidence of proteinuria. In a different setting, pregnancies complicated by preeclampsia are associated with elevated soluble VEGF receptor 1 protein (sFlt-1), endothelial cell dysfunction and proteinuria. These studies suggest that neutralization of physiologic levels of VEGF, a key endothelial survival factor, may lead to proteinuria. In the present study, we evaluated the potential of anti-VEGF neutralizing antibodies and sFlt-1 in the induction of proteinuria. Our studies demonstrate that anti-VEGF antibodies and sFlt-1 cause rapid glomerular endothelial cell detachment and hypertrophy, in association with down-regulation of nephrin, a key epithelial protein in the glomerular filtration apparatus. These studies suggest that down-regulation or neutralization of circulating VEGF may play an important role in the induction of proteinuria in various kidney diseases, some forms of cancer therapy and also in women with preeclampsia.  相似文献   
36.
The role of Asp-177 in the His-Asp catalytic dyad of glucose 6-phosphate dehydrogenase from Leuconostoc mesenteroides has been investigated by a structural and functional characterization of the D177N mutant enzyme. Its three-dimensional structure has been determined by X-ray cryocrystallography in the presence of NAD(+) and in the presence of glucose 6-phosphate plus NADPH. The structure of a glucose 6-phosphate complex of a mutant (Q365C) with normal enzyme activity has also been determined and substrate binding compared. To understand the effect of Asp-177 on the ionization properties of the catalytic base His-240, the pH dependence of kinetic parameters has been determined for the D177N mutant and compared to that of the wild-type enzyme. The structures give details of glucose 6-phosphate binding and show that replacement of the Asp-177 of the catalytic dyad with asparagine does not affect the overall structure of glucose 6-phosphate dehydrogenase. Additionally, the evidence suggests that the productive tautomer of His-240 in the D177N mutant enzyme is stabilized by a hydrogen bond with Asn-177; hence, the mutation does not affect tautomer stabilization. We conclude, therefore, that the absence of a negatively charged aspartate at 177 accounts for the decrease in catalytic activity at pH 7.8. Structural analysis suggests that the pH dependence of the kinetic parameters of D177N glucose 6-phosphate dehydrogenase results from an ionized water molecule replacing the missing negative charge of the mutated Asp-177 at high pH. Glucose 6-phosphate binding orders and orients His-178 in the D177N-glucose 6-phosphate-NADPH ternary complex and appears to be necessary to form this water-binding site.  相似文献   
37.
Zhu J  Xu X  Cosgrove JR  Foxeroft GR 《Theriogenology》2000,54(9):1443-1452
We applied IVM/IVF techniques to investigate effects of preincubation of sperm with different fractions of semen plasma harvested from fresh ejaculates on in vitro penetration and fertilization of in vitro matured oocytes. Three fractions of semen plasma were separated from the complete ejaculate of three Landrace boars and used to coincubate sperm obtained from the first sperm-rich fraction of the same ejaculates. After 14 to 16 h coincubation at room temperature, sperm were preincubated in capacitation medium and then inseminated into fertilization medium containing porcine oocytes matured in vitro. The semen plasma used for coincubation affected penetration rate (P < 0.001); Sperm coincubated with Fraction 1 semen plasma had a higher penetration rate compared with sperm coincubated with Fraction 2 (P < 0.05), but not with Fraction 3. Boar affected male pronucleus formation rates after insemination (P < 0.05), but no difference among boars was found in monospermy rate, average number of sperm penetrating into each fertilized oocyte, or the average number of sperm attached. No boar by fraction interaction was found for any parameters studied.  相似文献   
38.
Type IV collagen includes six genetically distinct polypeptides named alpha1(IV) through alpha6(IV). These isoforms are speculated to organize themselves into unique networks providing mammalian basement membranes specificity and inequality. Recent studies using bovine and human glomerular and testis basement membranes have shown that unique networks of collagen comprising either alpha1 and alpha2 chains or alpha3, alpha4, and alpha5 chains can be identified. These studies have suggested that assembly of alpha5 chain into type IV collagen network is dependent on alpha3 expression where both chains are normally present in the tissue. In the present study, we show that in the lens and inner ear of normal mice, expression of alpha1, alpha2, alpha3, alpha4, and alpha5 chains of type IV collagen can be detected using alpha chain-specific antibodies. In the alpha3(IV) collagen-deficient mice, only the expression of alpha1, alpha2, and alpha5 chains of type IV collagen was detectable. The non-collagenous 1 domain of alpha5 chain was associated with alpha1 in the non-collagenous 1 domain hexamer structure, suggesting that network incorporation of alpha5 is possible in the absence of the alpha3 chain in these tissues. The present study proves that expression of alpha5 is not dependent on the expression of alpha3 chain in these tissues and that alpha5 chain can assemble into basement membranes in the absence of alpha3 chain. These findings support the notion that type IV collagen assembly may be regulated by tissue-specific factors.  相似文献   
39.

Background

The majority of colorectal cancer (CRC) cases are preventable by early detection and removal of precancerous polyps. Even though CRC is the second most common internal cancer in Australia, only 30 per cent of the population considered to have risk factors participate in stool-based test screening programs. Evidence indicates a robust, blood-based, diagnostic assay would increase screening compliance. A number of potential diagnostic blood-based protein biomarkers for CRC have been reported, but all lack sensitivity or specificity for use as a stand-alone diagnostic. The aim of this study was to identify and validate a panel of protein-based biomarkers in independent cohorts that could be translated to a reliable, non-invasive blood-based screening test.

Principal Findings

In two independent cohorts (n = 145 and n = 197), we evaluated seven single biomarkers in serum of CRC patients and age/gender matched controls that showed a significant difference between controls and CRC, but individually lack the sensitivity for diagnostic application. Using logistic regression strategies, we identified a panel of three biomarkers that discriminated between controls and CRC with 73% sensitivity at 95% specificity, when applied to either of the two cohorts. This panel comprised of Insulin like growth factor binding protein 2 (IGFBP2), Dickkopf-3 (DKK3), and Pyruvate kinase M2(PKM2).

Conclusions

Due to the heterogeneous nature of CRC, a single biomarker is unlikely to have sufficient sensitivity or specificity for use as a stand-alone diagnostic screening test and a panel of markers may be more effective. We have identified a 3 biomarker panel that has higher sensitivity and specificity for early stage (Stage I and -II) disease than the faecal occult blood test, raising the possibility for its use as a non-invasive blood diagnostic or screening test.  相似文献   
40.
Soil fungal communities involved in the biodegradation of polyester polyurethane (PU) were investigated. PU coupons were buried in two sandy loam soils with different levels of organic carbon: one was acidic (pH 5.5), and the other was more neutral (pH 6.7). After 5 months of burial, the fungal communities on the surface of the PU were compared with the native soil communities using culture-based and molecular techniques. Putative PU-degrading fungi were common in both soils, as <45% of the fungal colonies cleared the colloidal PU dispersion Impranil on solid medium. Denaturing gradient gel electrophoresis showed that fungal communities on the PU were less diverse than in the soil, and only a few species in the PU communities were detectable in the soil, indicating that only a small subset of the soil fungal communities colonized the PU. Soil type influenced the composition of the PU fungal communities. Geomyces pannorum and a Phoma sp. were the dominant species recovered by culturing from the PU buried in the acidic and neutral soils, respectively. Both fungi degraded Impranil and represented >80% of cultivable colonies from each plastic. However, PU was highly susceptible to degradation in both soils, losing up to 95% of its tensile strength. Therefore, different fungi are associated with PU degradation in different soils but the physical process is independent of soil type.  相似文献   
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