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101.
Loss of mammalian Sprouty2 leads to enteric neuronal hyperplasia and esophageal achalasia 总被引:3,自引:0,他引:3
Taketomi T Yoshiga D Taniguchi K Kobayashi T Nonami A Kato R Sasaki M Sasaki A Ishibashi H Moriyama M Nakamura K Nishimura J Yoshimura A 《Nature neuroscience》2005,8(7):855-857
We report here that loss of the Sprouty2 gene (also known as Spry2) in mice resulted in enteric nerve hyperplasia, which led to esophageal achalasia and intestinal pseudo-obstruction. Glial cell line-derived neurotrophic factor (GDNF) induced hyperactivation of ERK and Akt in enteric nerve cells. Anti-GDNF antibody administration corrected nerve hyperplasia in Sprouty2-deficient mice. We show Sprouty2 to be a negative regulator of GDNF for the neonatal development or survival of enteric nerve cells. 相似文献
102.
Committing embryonic stem cells to early endocrine pancreas in vitro 总被引:12,自引:0,他引:12
Ku HT Zhang N Kubo A O'Connor R Mao M Keller G Bromberg JS 《Stem cells (Dayton, Ohio)》2004,22(7):1205-1217
A panel of genetic markers was used to assess the in vitro commitment of murine embryonic stem (ES) cells toward the endoderm-derived pancreas and to distinguish insulin-expressing cells of this lineage from other lineages such as neuron, liver, and yolk sac. There are two nonallelic insulin genes in mice. Neuronal cells express only insulin II, whereas the pancreas expresses both insulin I and II. Yolk sac and fetal liver express predominately insulin II, small amounts of insulin I, and no glucagon. We found that ES-derived embryoid bodies cultured in the presence of stage-specific concentrations of monothio-glycerol and 15% fetal calf serum, followed by serum-free conditions, give rise to a population that expresses insulin I, insulin II, pdx-1 (a pancreas marker), and Sox17 (an endoderm marker). Immunohistochemical staining shows intracellular insulin particles, and its de novo production was confirmed by staining for C-peptide. Most, but not all, of the insulin+ or C-peptide+ cells coexpress glucagon, demonstrating a differentiation pathway to pancreas rather than yolk sac or fetal liver. Addition of beta-cell specification and differentiation factors activin beta B, nicotinamide, and exendin-4 to later-stage culture increased insulin-positive cells to 2.73% of the total population, compared with the control culture, which gave rise to less than 1% insulin-staining cells. These findings suggest that stepwise culture manipulations can direct ES cells to become early endocrine pancreas. 相似文献
103.
Kawano Y Fukuda J Itoh H Takai N Nasu K Miyakawa I 《American journal of reproductive immunology (New York, N.Y. : 1989)》2004,52(2):124-128
PROBLEM: In order to investigate the role of macrophage colony-stimulating factor (M-CSF) and monocyte chemoattractant protein -1 (MCP-1) in human ovulation, we studied the regulation of M-CSF and MCP-1 in cultured human granulosa cells. METHOD OF STUDY: Immortalized granulosa cells (GC1a) were cultured in serum-free medium, and incubated with interleukin (IL)-1alpha, IL-1 receptor antagonist (ra) and tumor necrosis factor (TNF)-alpha. The supernatants were collected, and M-CSF and MCP-1 were measured by ELISA. RESULTS: The levels of M-CSF and MCP-1 were increased after treatment with IL-1alpha (1 nm) and TNF-alpha (1 nm) in a time-dependent manner. The levels of M-CSF and MCP-1 were significantly increased after treatment with IL-1alpha and TNF-alpha in a dose-dependent manner. However, the levels of M-CSF and MCP-1 were significantly decreased by treatment with IL-1alpha (1 nm) and/or increasing concentrations of IL-1 ra. CONCLUSIONS: Our data indicated that M-CSF and MCP-1 were regulated by IL-1alpha and TNF-alpha. It was suggested that M-CSF and MCP-1 may play an important role in human preovulatory processes. 相似文献
104.
Kawano F Wang XD Lan YB Yoneshima H Ishihara A Igarashi M Ohira Y 《The Japanese journal of physiology》2004,54(3):229-242
Effects of 9-week hindlimb suspension and 8-week recovery on air-righting reaction in response to drop from a supine position were studied in adult rats. The righting time in rats at the end of suspension (approximately 220 ms) was longer than the age-matched controls (approximately 120 ms, p <0.05). The unloading-related change in righting time was accompanied by lowered activities of electromyogram (EMG) and altered recruitment of both neck and back muscles at a specific stage of drop. After 8 weeks of reambulation, righting time recovered toward the control level (approximately 153 ms, p <0.05), but the EMG activity of back muscle was still less than controls. In contrast, the EMG of neck muscle during fall was even increased. The differences in the characteristics of the muscle fibers between two groups were minor. It is suggested that inhibition of recruitment, rather than the changes in the fiber characteristics, of neck and back muscles is one of the major causes of the slow air-righting. 相似文献
105.
Our previous study showed that the saliency of a target increases the gain of smooth pursuit initiation. In this study, we examined the interocular transfer of this effect in five humans. A square red frame surrounding the target was used as a cue to indicate the initial target position. In the cue condition, the responses were similar, irrespective of the eye to which the cue was presented, and were significantly larger than in the no-cue condition. The result suggests that central pathways that receive input from both eyes mediate the effect of saliency on smooth pursuit initiation. 相似文献
106.
The pre-B cell receptor (preBCR) plays critical roles in early B cell differentiation. It has been shown that not all muH chains are capable of pairing with surrogate light (SL) chains to form preBCR. Here, we established a novel system to differentially identify two types of early pre-B cell populations in bone marrow and fetal liver of mice, one producing SL-pairing muH chains and the other producing SL-non-pairing muH chains. The former population accounted for 80% of all the early pre-B cells in adult bone marrow, while it accounted for only 20% of those in fetal liver. Comparison of the two types of pre-B cell populations in fetal liver revealed the structural difference between SL-pairing and -non-pairing muH chains encoded by the V(H)81X segment that was most frequently utilized in fetal liver pre-B cells but rarely expressed by B cells generated in adults. PreBCR played an important role in the positive selection of V(H)81X-muH chains carrying the characteristic sequences of the complementarity-determining region 3 with little or no nibbling or N nucleotide addition, leading to their predominance in neonatal splenic B cells. These fetal-type V(H)81X-muH chains were also detected in adult spleen, but almost exclusively in marginal zone (MZ) B cells in contrast to the adult-type V(H)81X-muH chains. This strongly suggests that neonatally generated and selected B cells expressing the stereotyped V(H)81X-muH chains are maintained in the adult MZ and could function as innate-like lymphocytes. 相似文献
107.
Abe Y Chinzei T Isoyama T Kobayashi S Ono T Saito I Iwasaki K Ishimaru M Baba A Kouno A Ozeki T Tohyama T Imachi K 《ASAIO journal (American Society for Artificial Internal Organs : 1992)》2003,49(3):325-332
The undulation pump total artificial heart (UPTAH) is a unique, implantable, total artificial heart (TAH) that uses undulation pumps. To achieve long-term survival in animals with physiologic hemodynamic conditions, a control method based on conductance and arterial pressure was applied to UPTAH. With this control method, called 1/R control, survival periods of 50 days (No. 0016, 49.6 kg) and 54 days (No. 0030, 42.5 kg) were obtained in adult female goats. In No. 0016, 1/R control was applied to the left pump, whereas in No. 0030, it was applied to the right pump. Another pump was used for left-right balance control. The control stability was better in No. 0030 than in No. 0016. The sucking effect of the left atrium was remarkable in No. 0016, possibly because of a time delay when left-right balance control was performed with the right pump. In No. 0016, the cause of death was probably a thrombus flown from a panus in the left atrium. It is possible that the left atrial suction effect influenced the thrombus and panus formation in the left atrium. In No. 0030, the cause of death was a small rupture of the membrane in the right pump. The rupture may have been caused by excessive negative pressure inside the pump. This pressure resulted from suction of the right atrium because of an unexpected control excursion, which was probably caused by a software bug. It will be necessary to redesign the undulation pump and improve the software to achieve longer survival periods for animals with physiologic hemodynamic conditions. 相似文献
108.
Nozawa-Inoue K Ohshima H Kawano Y Yamamoto H Takagi R Maeda T 《Archives of histology and cytology》1999,62(5):483-491
The expression of heat shock protein 25 (Hsp 25) was investigated in the rat temporomandibular joint by immunocytochemistry combined with confocal and electron microscopy. Immunostaining with an antibody to Hsp25 was able to demonstrate various cellular elements in the synovial membrane of the joint. Intense immunoreaction for Hsp25 was recognized in certain cells comprising the synovial lining layer. Confocal microscopic observation revealed two characteristic profiles of the Hsp25-positive cells with cytoplasmic processes: one extended thick and long processes towards the articular cavity, and the other prejected horizontally slender processes which covered the synovial membrane. Under the electron microscope, the immunoreactive synovial lining cells were characterized by a well-developed rough endoplasmic reticulum and secretory granules, suggesting that they can be categorized as fibroblastic type B cells. The covering by the cytoplasmic extensions was confirmed by immuno-electron microscopic observations. This cytoplasmic covering presumably performs a barrier function and expedites the effective secretion/resorption of synovial fluids. Since it has been proposed that Hsp 25 is associated with an estrogen receptor, the immunopositive synovial lining cells were considered estrogen-target cells. Immunoreactivity for Hsp25 was also observed in the chondrocytes of the maturative and hypertrophic cell layers as well as in the cells of the articular disk. A suggestion was made that Hsp25 might be involved in the inhibition of apoptosis of those cells. 相似文献
109.
Atsushi Kikkawa Toshikazu Takata Takeshi Endo 《Macromolecular chemistry and physics.》1991,192(3):655-662
Cationic polymerization of styrene in the presence of 1-(p-methoxybenzyl)tetrahydrothiophenium hexafluoroantimonate ( 3 ) as an efficient cationic initiator was investigated. 3 was synthesized in an excellent yield by the reaction of p-methoxybenzyl bromide with tetrahydrothiophene and the subsequent exchange of bromide ions for hexafluoroantimonate ions. In the polymerization of styrene, 3 acted as a potent thermally latent initiator which initiates the polymerization at a slightly higher temperature than room temperature, although no polymerization occurs at room temperature for 30 min. 3 is a much more active initiator than the previously reported benzylsulfonium salt 1 . The enhanced activity of 3 was also confirmed in the polymerization of glycidylb phenyl ether. 相似文献
110.
Prospective clinical evaluation of the serologic tuberculous glycolipid test in combination with the nucleic acid amplification test 总被引:4,自引:0,他引:4
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Maekura R Kohno H Hirotani A Okuda Y Ito M Ogura T Yano I 《Journal of clinical microbiology》2003,41(3):1322-1325
We have conducted a prospective controlled multicenter study to evaluate differences in the levels of clinical utility of the tuberculous glycolipid (TBGL) serodiagnostic test and the nucleic acid amplification test in patients with smear-negative active pulmonary tuberculosis (TB). The TBGL test and the PCR test were individually not so useful for the rapid diagnosis of smear-negative active pulmonary TB. However, clinical utility was considerably improved by using the TBGL test and the PCR test in combination, especially in patients with smear-negative and culture-negative active pulmonary TB and in patients with minimally advanced lesions. 相似文献