首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 11 毫秒
1.
The expression and distribution of S-100 protein and type IV collagen was studied immunohistochemically in sympathetic neuroblasts from the paravertebral region to the adrenal glands in human embryos and fetuses ranging from 7 to 12 weeks gestational age. From 7 weeks gestational age, S-100 protein was detected in round or oval cells mingling with sympathetic neuroblasts, and in spindle-shaped cells forming a continuous layer around them. The latter S-100 protein-positive cells were found in contact with the Schwann cells of nerve fibres entering the groups of sympathetic neuroblasts. Staining for type IV collagen showed that all groups of sympathetic neuroblasts were surrounded by a continuous basement membrane. By examining serial sections stained for type IV collagen and S-100 protein, a continuous basement membrane was found along the distribution pattern of the peripheral S-100 protein-positive spindle cells. The morphology of these cells, and their relationships with Schwann cells and with the basement membrane of the sympathetic neuroblasts, indicated that they were Schwann-like cells probably capable of synthesizing a continuous basement membrane separating the neuroblasts from the adjacent tissues. In contrast, the round or oval S-100 protein-positive cells, in contact with the sympathetic neuroblasts and not associated with nerve fibres, were considered as sustentacular or sustentacular precursor cells. At week 7 gestational age, the peri-adrenal sympathetic neuroblasts and their sustentacular and Schwann-like cells started to invade the adrenal glands and mingled with the adrenal cortical cells. These findings suggest the extra-adrenal origin of the sustentacular cells in embryonic and fetal adrenal glands.  相似文献   

2.
Phlebotomus duboscqi and P. papatasi are morphologically closely related species. Scanning electron microscopy showed constant differences between pharyngeal teeth of the females.  相似文献   

3.
To assess recall of childhood socioeconomic position for public health research, the authors conducted a cross-sectional study of 352 adult women twin pairs enrolled in Examination II of the Kaiser Permanente Women Twins Study carried out in 1989-1990 in Oakland, California. Among twin pairs, 91% (95% confidence interval (CI) 89-94%) agreed on their father's educational level and 81% (95% CI 77-85%) on their childhood social class. Recall did not differ by adult socioeconomic position, zygosity, race/ethnicity, or age. Thus, epidemiologic studies can validly use retrospective data on childhood socioeconomic position to study its relation to adult health status.  相似文献   

4.
During their autumn migratory phase, thrush nightingales (Luscinia luscinia) previously starved for 2 d were allowed to refuel under three different ambient temperature conditions (-7 degrees, 7 degrees, and 22 degrees C). During the refueling period, as well as during the preceding control and starvation periods, food intake, body mass, and feces production were monitored. In addition, daily energy expenditure was measured during the refueling period. The compilation of the energy balance during the refueling period revealed an energy density of the deposited tissue of 33.6 kJ g-1. Assuming that the deposited tissue consists of fat and protein exclusively, with energy densities of 39.6 and 5.5 kJ g-1 wet mass, respectively, we estimated the deposited tissue to consist of 82% fat and 18% wet protein (6% dry protein and 12% water). Nitrogen balances during control, starvation, and refueling phases and during a period of prolonged and complete starvation indicated that 5% of the nutrient stores consisted of dry protein. Our results support recent findings that nutrient stores for migration often contain protein in addition to fat and consequently are 15%-25% less energy rich than pure fat stores. These proteins might be stored as muscle or other functional tissue and may be required to support the extra mass of the stores and/or reflect an incapacity of the metabolic machinery to catabolize far exclusively. Fuel deposition rate was positively related with ambient temperature, whereas food intake rate was unaffected by temperature. These results indicate that the rate of fuel deposition is limited by a ceiling in food intake rate; when this ceiling is reached, fuel deposition rate is negatively affected by daily energy expenditure rate. To a certain extent, the ceiling in food intake rate varies depending on feeding conditions over the previous days. These variations in food intake capacity probably reflect the building and breakdown of gut tissues and/or gut enzyme systems and might be insensible and not evolutionary adaptive. Significant energetic costs, however, are probably associated with the maintenance of gut tissues. It is therefore feasible that changes in digestive capacity are regulated and are directed at energy economization.  相似文献   

5.
In this study we measured S-100B using a recently developed luminometric immunoassay with a detection limit of 0.02 microg l(-1). By measuring serum S-100B concentrations in 58 apparently healthy individuals a reference value of 0.16 microg l(-1) was found. To assess the sensitivity of the assay we measured levels of S-100B protein in the serum of 251 patients with cutaneous malignant melanoma before the start of treatment. Only one of 179 patients with limited disease had a serum concentration higher than the reference value, whereas elevated levels were seen in 79% of patients with metastasized disease. In the latter group the NSE serum concentration was elevated in 42%. Using a receiver operating characteristic (ROC) curve it is shown that S-100B is a significantly better parameter than neuron-specific enolase (NSE) for distinguishing patients with limited disease from those with extensive melanoma. Pretreatment S-100B values were highly predictive for the period of survival. Patients with limited disease have increased risk for early death with increasing levels of S-100B protein. Within the group of patients with positive lymph nodes and/or with distant metastases, elevated S-100B levels strongly identified high-risk patients. Our study indicates that the measurement of S-100B as a tumour marker in the management of patients with cutaneous malignant melanoma has clinical significance.  相似文献   

6.
Hereford cows with naturally occurring ocular squamous cell carcinoma were treated by injection of BCG cell-wall vaccine into the tumor. Regression or arrest of disease was observed in 71% of treated animals. The disease progressed in all untreated animals and animals treated with improperly compounded vaccine. At autopsy, most animals with progressive disease had lymph node metastases.  相似文献   

7.
Data on physico-chemical properties and functional role of protein S-100 have been generalized. An analysis of literary data permits making a conclusion that the protein interaction with Ca2+ ions plays great part in its action mechanisms. Data are presented on the properties of the family of Ca-binding proteins similar to protein S-100 as to their structure. Peculiar attention is paid to the analysis of this protein function in the cellular nucleus, changing the degree of proteins phosphorylation and RNA synthesis.  相似文献   

8.
Homozygotes of a mouse strain with genetic polydactyly (Pdn) show disrupted cortical lamination and a significant decrease of S-100beta-immunoreactive elements in a particular area of the brain. In order to understand the abnormal cortical formation at the cellular level, the migration of cortical neurons and the development of glial cells were studied using bromodeoxyuridine (BrdU), S-100beta, and glial fibrillary acidic protein (GFAP) immunohistochemistry. Homozygous mice (Pdn/Pdn) displayed a variable pattern of abnormalities. Irregular GFAP-positive radial glial cells and disturbance of neuronal migration were found in a circumscribed area of the caudo-dorsal cortex of newborn Pdn mouse. The number of S-100beta-positive cells was reduced in this area. The present results suggest that abnormal cortical lamination closely correlates with disturbance of neuronal migration and abnormalities of glial cells, especially a significant decrease of S-100beta-immunoreactive cells.  相似文献   

9.
10.
Mutation of the TP53 gene is one of the most common molecular alterations in a variety of tumors, but it occurs infrequently in childhood and adult hematological malignancies. Protein accumulation often results from mutations that lead to inactivation of the p53 protein. Other causes of functional inactivation of the p53 protein include stabilization of p53 via proteins such as MDM2, an oncoprotein capable of forming specific complexes with p53. In the present study, protein expressions of MDM2 and p53 were investigated by immunohistochemistry from bone marrow samples in 23 patients with acute lymphoblastic leukemia aged 1-13 years at diagnosis. p53 protein overexpression was detected in only one case, while overexpression of MDM2 was detected in samples from five patients. All five patients overexpressing MDM2 belonged to a group with unfavorable prognostic signs at diagnosis and three of them relapsed or died within 6 months after diagnosis.  相似文献   

11.
All solid tumors must acquire a vascular stroma to grow beyond a minimal size. Vascular endothelial growth factor (VEGF) is a potent and specific angiogenic growth factor both in vitro and in vivo that may participate in the formation of the vascular tumor stroma. In the present study, we examined the expression of VEGF in the paraffin sections of 20 eyes harboring retinoblastoma or posterior uveal melanoma, but also in corresponding tumor cellines. By using in situ hybridization, we found that all but one of the retinoblastomas expressed VEGF mRNA. Particularly high expression was detected in areas of loosely packed tumor cells with prominent chromatin. By contrast, none of the posterior uveal melanomas expressed significant amounts of VEGF mRNA. Immunostaining with an antibody against VEGF confirmed that retinoblastomas, but not posterior uveal melanomas, also contained detectable VEGF protein. To further study the expression of VEGF in these tumor cells we performed Northern blotting on a retinoblastoma celline, Y79, and on an uveal melanoma celline, OM431. Both of these cellines expressed low levels of VEGF mRNA under normal culture conditions. However, when the cells were cultured under hypoxic conditions, a strong increase in VEGF mRNA could be seen in Y79 cells but not in OM431 cells. By using a bioassay, we also found that hypoxia stimulated the secretion of VEGF protein into the culture medium of Y79 cells. In conclusion, we have shown that VEGF mRNA and protein are expressed in retinoblastomas but not in posterior uveal melanomas. Moreover we have shown that VEGF is hypoxia-inducible in retinoblastoma cells. These results suggest that focal hypoxia may act as a stimulus for VEGF production in retinoblastomas, that in turn may contribute to tumor growth by stimulating the formation of a vascular stroma.  相似文献   

12.
S100 proteins are calcium-binding proteins of the EF-hand superfamily and are involved in the regulation of a number of cellular processes. The present study deals with the immunohistochemical expression of S100A1 and S10100A6 in the rat submandibular and sublingual glands during postnatal development from day 0 to 12 weeks. Expression of S100A1 was particularly concentrated in pillar and transition cells in the granular convoluted tubule (GCT) and in striated duct cells of the submandibular gland age 4 weeks to maturity. None or only weak staining for S100A1 was observed in the duct segment at 0-5 days. On the contrary, immunostaining of S100A6 was present in proacinar cells in undifferentiated submandibular gland at age 3 days to 2 weeks. S100A6 immunoreactivity in rat submandibular gland coexisted with chromogranin reactivity. It is possible that S100A6 regulates secretion of chromogranin in proacinar cells. Secretion of growth factors and biologically active peptides in the GCT are regulated by calcium signals, and S100A1 may be involved in the secretory mechanism of granular cells. S100A1 and S100A6 are potentially of great importance in secretory functions of granular cells and proacinar cells, as well as in rat salivary glands.  相似文献   

13.
The temporospatial distribution of bovine primordial germ cells was studied in 34 embryos (18 to 39 days). For a reliable identification of bovine primordial germ cells in varying localizations and at different developmental stages the alkaline phosphatase reaction combined with the use of selected lectins was applied. The first potential primordial germ cells were identified in an 18-day-old trilaminar embryo in the caudal wall of the proximal yolk sac at a distance of less than 100 microm from the germ disc. These cells are alkaline phosphatase-positive. but do not yet react with lectins. From 18 through 23 days, morphogenetic folding converts the flat trilaminar disc into a cylindrical embryonic body. During this folding process primordial germ cells located in the proximal yolk sac area are incorporated into the embryo when this portion of the yolk sac becomes the hind- and mid-gut. Consequently, in 23- to 25-day-old embryos putative primordial germ cells (alkaline phosphatase- and lectin-positive) are situated predominantly in the axial body region at the level of the mesonephros. When the gonadal ridge develops in this region (about day 27) it contains a certain number of primordial germ cells present from the very beginning. Thus, the assumptions of a long-range chemoattraction of primordial germ cells by the gonadal ridge, of active immigration from an extraembryonic site. or of a passive transportation via the blood stream are not necessary to explain the initial settlement of bovine primordial germ cells in the gonadal ridge. Within the gonadal ridge (days 27-31) and later in the still sexually indifferent gonadal fold (32-39 days) the primordial germ cells are unevenly distributed. Extragonadal potential primordial germ cells (alkaline phosphatase-positive, but with reduced or no lectin staining) are regularly present in large numbers in bovine embryos with indifferent gonads. Such cells occur predominantly in the paraaortal tissue and in the liver, but also in the branchial arches. The different locations of extragonadal primordial germ cells are discussed in the light of recent evidence that germ cells and haematopoietic cells share common ancestors.  相似文献   

14.
We investigated the time course of neuron specific enolase (NSE) and S-100 protein after severe head injury in correlation to outcome. We included 30 patients (GCS < 9), who had been admitted within 5 hours after injury, in a prospective study. Blood samples were taken on admission, 6, 12, and 24 hours and every 24 hours up to the fifth day after injury. The outcome was estimated on discharge using the Glasgow Outcome Scale. 70% reached a good outcome. All concentrations of NSE and 83% of the S-100 samples were elevated concerning the first probe (30.2 micrograms/l NSE mean and 2.6 micrograms/l S-100 mean). Patients with bad outcome had an NSE concentration of 38 micrograms/l (mean) compared with 26.9 micrograms/l (mean) in patients with good outcome. Patients with bad outcome had an S-100 concentration of 4.9 micrograms/l (mean) compared with 1.7 micrograms/l (mean) in patients with good outcome (p < 0.05). The mean values of NSE and S-100 decreased during the first 5 days. Four patients with increasing intracranial pressure showed a quick increasing concentration of NSE, in two patients the S-100 level showed a slower rise. The NSE serum levels did not correlate with intracranial pressure values. Our results show that the first serum concentration of S-100 seems to be predictive for outcome after severe head injury.  相似文献   

15.
We evaluated S-100 levels in paired cerebrospinal fluid (CSF) and serum samples in a group of 135 patients referred to the German Creutzfeldt-Jakob disease (CJD) surveillance unit from June 1993 to May 1995. The patients were seen in a prospective case control study. The diagnosis of probable CJD during life was made in any patient presenting with rapidly progressive dementia of less than 2 years' duration, typical periodic sharp wave complexes (PSWCs) in the EEG and at least two of the following findings: myoclonus, visual/or cerebellar symptoms, pyramidal and/or extrapyramidal signs and/or akinetic mutism. Patients presenting with the above clinical signs and symptoms but without PSWCs were classified as possible, while those with a dementia of a duration exceeding 2 years and without PSWCs were classified as other. S-100 was determined in paired CSF and serum samples by a commercially available enzyme-linked immunosorbent assay. In a group of 76 patients with definite and probable CJD, S-100 concentration (median 25 ng/ml, range 2-117) in CSF was significantly higher (P < 0.0001) than in 32 patients diagnosed as other (median 4 ng/ml, range 1-19). Serum levels of S-100 were below 0.5 ng/ml in all groups. At a cut-off of 8 ng/ml an optimum sensitivity of 84.2% with a specificity of 90.6% for the diagnosis of CJD by the determination of S-100 in CSF is obtained. S-100 levels exceeding 8 ng/ml in CSF support the diagnosis of CJD in any patient presenting with rapidly progressive dementia.  相似文献   

16.
BACKGROUND: A 360 degrees or Nissen fundoplication remains controversial in patients with disordered peristalsis, some surgeons preferring a partial wrap to minimise postoperative dysphagia. AIM: To evaluate symptoms and manometric outcome in patients with disordered peristalsis after Nissen fundoplication. PATIENTS: In an initial series of 345 patients studied prospectively, 31 patients who had undergone a Nissen fundoplication had disordered peristalsis. Using preoperative manometry, patients were classified as: equivocal primary peristalsis (eight patients); abnormal primary peristalsis (four patients); abnormal maximal contraction pressure (13 patients); abnormal primary peristalsis and maximal contraction pressure (six patients). METHODS: Postoperatively, patients underwent a barium meal, oesophageal manometry and standardised clinical review by a blinded scientific officer. RESULTS: Twenty eight (90%) patients had satisfaction scores of at least 8 out of a maximum of 10 and all would undergo surgery again. Whereas 15 (48%) patients had dysphagia scores greater than 4/10 preoperatively, only two (6%) had these scores at one year. Improved peristalsis was seen in 78% of postoperative manometric studies, and mean preoperative lower oesophageal sphincter pressure increased from 6.6 (range 0-21) mm Hg to 19 (4-50) mm Hg. CONCLUSIONS: These results are similar to the overall group of 345 patients and suggest that disordered peristalsis, and possibly even absent peristalsis, is not a contraindication to Nissen fundoplication as performed in these patients.  相似文献   

17.
Somatostatin-14 (S-14) and somatostatin-28 (S-28) are generated by differential processing of a single precursor at a dibasic (R-K) or monobasic (R) proteolytic cleavage site, respectively. To study the pathways of processing of prosomatostatin, we have expressed in AtT20 cells cDNA encoding human prosomatostatin and prosomatostatin mutated in one or the other processing site. Analysis of the peptides present in cell extracts or culture media before and after stimulation of the cells with 8-BrcAMP indicated that prosomatostatin can enter three distinct secretory pathways where it is differently processed: 1) prosomatostatin was secreted through the constitutive pathway; 2) the regulated secretory pathway generated S-14 which was released upon stimulation of the cells with 8-BrcAMP; 3) an alternative pathway, insensitive to 8-BrcAMP produced S-28 and S-14. Moreover, our results suggest that the R-K processing site used to produce S-14 is an important structural feature for targeting the precursor to the regulated secretory pathway.  相似文献   

18.
OBJECTIVE: To establish a reliable, rapid, economical method for detection of pestivirus infection in bovine and ovine fetuses and to examine participation of these viruses in abortions and neonatal mortality. ANIMALS: 213 bovine and 31 ovine fetuses, as well as 36 newborn calves and 25 lambs, which had died within 3 days after birth, were tested for bovine viral diarrhea virus (BVDV) and border disease virus by use of different methods. PROCEDURE: Detection of BVDV in fetuses was performed by immunohistochemical methods, using a panel of monoclonal antibodies against pestivirus antigens on cryostat and paraffin sections and by virus isolation in cell culture; in some instances, an antigencapture ELISA was performed. Results of the various methods were compared. RESULTS: Sensitivity of BVDV detection by immunohistochemical methods and virus isolation in cell culture was equal; however, it decreased in association with autolysis. In autolytic fetuses, use of formalin-fixed, paraffin-embedded brain sections was the most favorable method. Antigen detection by ELISA was less sensitive. CONCLUSIONS: Immunohistochemical analysis of cryostat sections of brain, skin, thyroid gland, abomasum, and placenta is a rapid, sensitive method for detecting pestiviruses in fetuses. In the presence of advanced autolysis, this method used on formalin-fixed, paraffin-embedded brain sections is recommended over the other described methods.  相似文献   

19.
Although myoepithelial cells are detectable in many benign sweat gland tumours, little is known about their role in sweat gland carcinomas. To specifically demonstrate myoepithelial cells, paraffin sections from 46 sweat gland carcinomas were stained, using a standard avidin-biotin-peroxidase complex method, with the monoclonal alpha-smooth muscle actin antibody 1A4. Myoepithelial cells were not found in adenoid cystic eccrine carcinoma (n = 2), malignant nodular hidradenoma (n = 2), porocarcinoma (n = 4), extramammary Paget's disease (n = 12), sclerosing sweat duct carcinoma (n = 4) or in adenosquamous-mucoepidermoid carcinoma (n = 1). In contrast, myoepithelial cells were demonstrated in two of eight apocrine adenocarcinomas, one of six mucinous eccrine carcinomas and two of seven eccrine adenocarcinomas. In all these tumours myoepithelial differentiation was found in peripheral cells of solid tumour islands, or in basal cells of tubular structures. However, in most areas of the tumours, myoepithelial layers were discontinuous. Cells in the centre of solid tumour nodules, and luminal cells of tubular structures, were negative for alpha-smooth muscle actin. In analogy to breast tumours, in which malignancy and invasiveness correlate with scattered or absent myoepithelial cells, we suggest that disrupted myoepithelial layers in sweat gland carcinomas may be interpreted as a loss of the invasion barrier.  相似文献   

20.
Previous studies from this laboratory had indicated that metalloproteolytic activity was present in the interphotoreceptor matrix. This report extends those observations by providing evidence for the presence of multiple forms of metalloproteinase and for their polarized distribution within the interphotoreceptor matrix as determined by zymogram analysis on substrate-loaded gels. Retinal pigment epithelium-associated interphotoreceptor matrix, both unfractionated as well as fractions separated by gel filtration, exhibited bands of proteolytic activity on gelatin-loaded gels at about 70-75 kDa and 90 kDa, possibly due to gelatinases A and B (MMP-2 and MMP-9, respectively). In contrast, no neutral proteolytic activity was seen in retina-associated interphotoreceptor matrix unless it was first fractionated by gel filtration, whereupon a diversity of forms was exhibited, including additional major bands of proteolytic activity at about 150 kDa and 100 kDa, on gelatin-loaded gels, and at about 180 kDa, on casein-loaded gels, along with many minor species. In all cases, all proteinase activity was inhibited by chelating agents. Since these enzymes may be involved in the turnover and remodeling of components present in the interphotoreceptor matrix, many of which are distributed in a compartmentalized fashion, this unequal distribution of metalloproteinases may be correlated with substrate specificity.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号