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1.
In this study, we showed that feeding rats the organic extract of scallop shells (scallop shell extract) caused a decrease in the weights of white adipose tissues in rats fed a high-fat diet. In addition, the cholesterol concentration in the serum of rats that received a diet containing scallop shell extract was significantly lower than that in the serum of rats on the control diet. Feeding this scallop shell extract to rats increased the fecal weight as well as the fecal excretion of bile acids. The amino acid composition of the feces from rats fed the scallop shell extract was different from that of feces from rats fed the control diet, and treatment of the extract with pepsin and pancreatin identified a protein with a molecular weight of 90 kDa (90-kDa protein) as one of the indigestible proteins. Interestingly the 90-kDa protein was found to be identical to a free radical-scavenging protein we previously identified and showed the ability to bind bile acids. These results suggest that indigestible proteins (resistant proteins) in the scallop shell extract, including the 90-kDa protein, inhibit the absorption of bile acid by binding to it and cause increased excretion of fecal bile acid, which subsequently may decrease the serum cholesterol level.  相似文献   
2.
冰藏鲢的鲜度变化对其鱼糜凝胶作用的影响   总被引:13,自引:0,他引:13  
通过比较不同冰藏时间的鲢所制鱼糜在各种加热温度下的凝胶化和凝胶劣化的特性,考察了鲢的鲜度变化与鱼糜凝胶作用能力的关系。实验结果表明:冰藏0 ̄9天鲢鱼糜,在30℃低温一段加热时凝胶的形成与链鲜度关系不大;85℃一段加热时,凝胶化能力随鲜度下降而降低;30 ̄85℃二段加热与30℃一段加热相比,两者凝胶破断强度之间的差值随鲢鲜度的下降而减小;60℃加热条件下,凝胶劣化程度随原料鲜度下降而明显加剧。据此可见:鲜度对鲢鱼糜凝胶作用能力的影响主要表现在凝胶劣化方面。85℃高温一段加热和30 ̄85℃二段加热的凝胶强度之所以受鲜度下降而影响,都是由于加热时经过了易劣化的60℃温度区所致。从总体上看,鲢肉蛋白质在冰藏条件下较为稳定,保持较强的凝胶化能力。  相似文献   
3.
We performed a pathologic examination of the brains of three dogs in an epileptic beagle colony. Histologically, all the cases had diffuse astrocytosis in the cerebral cortex and basal ganglia as well as the hippocampus, whereas they showed acute nerve cell change in the hippocampus and some other areas of the cerebrum. One of these animals showed laminar myelin pallor associated with the presence of many vacuoles in the IV to VI layers of the bilateral motor cortices. Most of the vacuoles contained fine granules stained with luxol-fast-blue stain. Ultrastructural examination revealed that some oligodendrocytes and perineuronal satellite oligodendrocytes in the bilateral cerebral motor cortices of the two affected dogs had many vacuoles surrounded by myelin-like lamellar structures. These findings suggest a possibility that astrocytosis in the cerebrum and vacuolar degeneration of oligodendrocytes in the cerebral motor cortex may be, at least in part, related to the occurrence or development of seizures.  相似文献   
4.
Isolation and culture of rabbit primordial germ cells   总被引:2,自引:0,他引:2  
Primordial germ cells (PGCs) are embryonic precursors of the gametes of adult animals and are considered stem cells of the germline. Since their proliferation in vitro correlates well with the schedule of developmental changes in vivo, they might be interesting research tools for genomic imprinting, germ-cell tumors and fertility. Furthermore, once primordial germ cells are separated and placed on a feeder layer with cytokines, they become cultured pluripotent cell lines called embryonic germ (EG) cells. EG cells share several important characteristics with embryonic stem (ES) cells as they can also contribute to the germ line of chimeras. To investigate the characteristics of PGCs and establish rabbit EG (rEG) cells, we cultured rabbit PGCs (rPGCs) in vitro with various combinations of leukemia inhibitory factor (LIF), basic fibroblast growth factor (bFGF) and forskolin on inactivated mouse embryonic fibroblast (MEF) feeder layers. The present study found PGC proliferation in early cultures and induction of rEG-like colonies. These cells expressed pluripotent markers, such as alkaline phosphatase activity, OCT-4, Sox-2 and SSEA-1, in the undifferentiated state; however, the cells did not develop into a teratoma when injected into the kidney capsules of SCID mice, although the restricted differentiation potentials to neural cells were determined via embryoid body formation. From these characteristics and further characterization of the germ stem cell markers Vasa, SCP-1 and SCP-3, we suggested that these were hybrid cells with characteristics somewhere between PGC and EG cells.  相似文献   
5.
To assess whether the antigenic properties of H5 hemagglutinin (HA) change over time due to antigenic drift, we produced a panel of monoclonal antibodies (mAbs) against the HA of the index H5N1 human influenza A virus, A/Hong Kong/156/97. By immunizing mice with a plasmid expressing this HA and boosting the initial immunization with cell lysates transfected with the plasmid, a total of six hybridomas producing HA-specific mAbs were established: four to the HA1 subunit with hemadsorption-inhibiting activity and two to the HA2 subunit. None of the mAbs to HA1 could bind to the HA of a recent human isolate, A/Hong Kong/213/2003, indicating that there are substantial antigenic differences between the H5N1 human influenza virus isolated in 1997 and that isolated in 2003.  相似文献   
6.
Ghrelin, a novel 28-amino acid peptide with an n-octanoyl modification at Ser3, has been isolated from rat and human stomach as an endogenous ligand for the growth hormone secretagogue receptor. Here, we purified feline ghrelin and examined its possible physiological role in cats. The major active form of feline ghrelin is a 28-amino acid peptide octanoylated (C8:0) at Ser3; except for one amino acid residue replacement, this structure is identical to those of rat and human ghrelins. However, much structural divergence in peptide length and fatty acid modification was observed in feline ghrelin: peptides consisting of 27 or 26 amino acids lacking Gln14 and/or Arg28 were found, and the third serine residue was modified by octanoic acid (C8:0), decanoic acid (10:0), or unsaturated fatty acids (C8:1, C10:1 and C10:2). In agreement with the structural divergence, two kinds of cDNA with different lengths were isolated. Administration of synthetic rat ghrelin increased plasma growth hormone levels in cats, with a potency similar to that in rat or human. Plasma levels of ghrelin in cats increased approximately 2.5-fold after fasting. The present study indicates the existence of structural divergence in feline ghrelin and suggests that, as in other animals, ghrelin may play important roles in GH release and feeding in cats.  相似文献   
7.
SUMMARY: Two trypsins, designated as trypsin A and trypsin B, have been purified from the hepatopancreas of carp. The purification procedures consisted of ammonium sulfate fractionation, and chromatographies on DEAE-Sephacel, Ultrogel AcA54 and Q-Sepharose. Trypsin A was purified to homogeneity with the molecular mass of approximately 28 kDa, while trypsin B gave two close bands of 28.5 kDa and 28 kDa on sodium dodecylsulfate polyacrylamide gel electrophoresis both under reducing and non-reducing conditions. On native-PAGE, both trypsin A and trypsin B showed a single band. Trypsin A and trypsin B revealed optimum temperature of 40°C and 45°C, respectively, and shared the same optimum pH 9.0 using Boc-Phe-Ser-Arg-MCA as substrate. Both enzymes were effectively inhibited by trypsin inhibitors and their susceptibilities were similar. The NH2-terminal amino acid sequences of trypsin A and trypsin B were determined to 37th and 40th amino acid residue, respectively. Their sequences were very homologous, but not identical to that of a trypsin-type serine proteinase from carp muscle and these of other trypsins. Immunoblotting test using the antibody raised against trypsin A cross-reacted with trypsin B positively.  相似文献   
8.
Age-related changes in bone mineral density (BMD), cross-sectional area and strength strain index (SSI) of the long bones in the limbs and first lumbar vertebra of male Wistar rats were measured by a peripheral quantitative computed tomography (pQCT) method. One hundred and ten rats aged 2-30 months were used. The results indicate that the total (cortical + trabecular), cortical and trabecular BMD values of the metaphysis and cortical BMD values of the diaphysis in the long bones varied for each bone and differed from those of the first lumbar vertebra. The total BMD of long bones showed high values at 6-21 months and then decreased, but these did not always coincide with cortical and trabecular BMD. The values of SSI in the long bones varied. The values of total and cortical BMD and SSI of lumbar vertebra increased for 6-12 months and then decreased, but the trabecular BMD increased after 12 months. The total area in both the long bones and the first lumbar vertebra increased with the decrease in cortical area and the increase in the trabecular area with increasing age. It was concluded that age-related changes in bones, similar to those observed in humans, could be observed in some bones and parameters, although the age in rats when the so-called peak bone mass appears in the whole skeleton could not be clearly determined.  相似文献   
9.
The correlation between the serum hydroxyproline concentration and serum activity levels of TRAP and BALP was examined in 41 cows. The correlated coefficient (r) was 0.6391 for TRAP and 0.3147 for BALP, respectively. Judging from the significant correlation to the serum hydroxyproline concentration, serum TRAP activity is an index for bone metabolism in cows. Serum TRAP activity was therefore measured in 205 healthy cows (2-9 years old) in order to observe the changes in bone resorption with aging and milk production. TRAP levels differed slightly between group A (< or =4 yrs) and B (5 yrs< or =) at the same stage of lactation. The activity levels rose slightly at the height of lactation stage and during the dry stage.  相似文献   
10.
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