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 31 毫秒
1.
Mixed sweat-gland tumors were studied on 11 biopsies, of which two showed clear-cut morphological features of malignancy. Stress was laid upon the sudoriferous-duct histogenesis of such tumors. Several peculiarities were carefully investigated, especially epithelial proliferation in sheets, cords, tubes, isolated cells and certain epithelial metaplasias correlated with various mesenchymal stroma changes, such as fibrosis, myxoid, chondroid or even osseous changes. Special emphasis was also laid upon the comparative aspects between benign and malignant mixed sweat-gland tumors and other similar body tumors.  相似文献   

2.
Here we describe gross and microscopic sweat gland tumors found in a transgenic mouse model of breast cancer, which had transforming growth factor α under the control of mouse mammary tumor virus promoter (MMTV-TGFα). Initially, 20% of the mice in the colony were affected. Cystic lesions formed on the phalanges, palmar surfaces of the metacarpals, and plantar surfaces of the metatarsals. The lesions were multifocal and nonulcerated with straw-colored fluid, ranging in size from 1 to 30 mm at the largest dimension. The colony was monitored for 6 mo; during that time, the prevalence of lesions increased to 52% of the mice. Histologically, in most cases the cyst walls were lined by 1 or 2 layers of normal-appearing epithelial cells that resembled basal cells, indicating adenoma. However, 2 cysts from 2 different mice had papillary proliferative projections and extensive disorganized glandular structures that protruded into the cyst cavities, indicating adenocarcinoma. In these 2 cases, the neoplastic cells revealed architectural and cytologic atypia with rare mitoses. Similar findings have previously been observed in sweat gland tumors; however, multiple sweat-gland tumors have not been reported in mice.  相似文献   

3.
4.
Several studies found simian virus 40 (SV40) in 47% to 83% of human mesotheliomas. Mesotheliomas are malignant tumors of the pleura and peritoneum, firmly associated with asbestos exposure. In this issue, Gazdar and colleagues ?Shivapurkar et al., 1999 found that SV40 is present only in the malignant cells and not in the surrounding stromal cells. Using the microdissection technique, they found SV40 in 54% of 93 mesotheliomas of the epithelial type. The surrounding reactive stromal cells, (20 lung cancers and 14 mesotheliomas of the sarcomatoid/fibrous type) did not contain SV40, confirming the specificity of their positive findings. Furthermore, SV40 was found in 14% of 14 non-malignant reactive mesothelial cell proliferations. In 12 cases of mesothelioma a noninvasive (or in situ) component was also identified. In all four cases in which SV40 sequences were present in the invasive component, sequences were also present in the accompanying noninvasive component. These data suggest that the virus resides in the mesothelial cells prior to tumor development. The data address the remaining concerns raised at an International Meeting organized by the NIH, FDA, and CDC in 1997 to definitively associate SV40 with human mesothelioma. It is time now to investigate the pathogenic mechanisms of this association, and if SV40-infected mesothelial cells are more susceptible to other carcinogens, such as asbestos. Furthermore, we must investigate the interaction between the host immune system and SV40-infected mesothelial cells, and study if the immunosuppressive activity of asbestos interferes with tumor rejection. These studies should lead to a better understanding of mesothelioma pathogenesis, and possibly to new therapeutic approaches aimed at interfering with the expression of the SV40 genome and/or at eliciting a strong immune response against SV40 infected mesothelial cells.  相似文献   

5.
Human eccrine sweat-gland recruitment and secretion rates were investigated from the glabrous (volar) and non-glabrous hand surfaces during psychogenic (mental arithmetic) and thermogenic stimuli (mild hyperthermia). It was hypothesised that these treatments would activate glands from both skin surfaces, with the non-thermal stimulus increasing secretion rates primarily by recruiting more sweat glands. Ten healthy men participated in two seated, resting trials in temperate conditions (25–26 °C). Trials commenced under normothermic conditions during which the first psychogenic stress was applied. That was followed by passive heating (0.5 °C mean body temperature elevation) and thermal clamping, with a second cognitive challenge then applied. Sudomotor activity was evaluated from both hands, with colourimetry used to identify activated sweat glands, skin conductance to determine the onset of precursor sweating and ventilated sweat capsules to measure rates of discharged sweating. From glandular activation and sweat rate data, sweat-gland outputs were derived. These psychogenic and thermogenic stimuli activated sweat glands from both the glabrous and non-glabrous skin surfaces, with the former dominating at the glabrous skin and the latter at the non-glabrous surface. Indeed, those stimuli individually accounted for ~90% of the site-specific maximal number of activated sweat glands observed when both stimuli were simultaneously applied. During the normothermic psychological stimulation, sweating from the glabrous surface was elevated via a 185% increase in the number of activated glands within the first 60 s. The hypothetical mechanism for this response may involve the serial activation of additional eccrine sweat glands during the progressive evolution of psychogenic sweating.  相似文献   

6.
Red chili pepper (Capsicum frutescens) is a highly consumed spice throughout the world. Its principal pungent ingredient is the phenol capsaicin (8-methyl-N-vanillyl-6-nonenamide). Capsaicin causes neurogenic inflammation and has analgesic and anti-inflammatory activities. We have observed previously that dendritic cells, a key cell type in immune responses, have the receptor for capsaicin, and engagement of this receptor has powerful immune consequences. In this study, we demonstrate that intratumoral administration of capsaicin into a preexisting tumor results in retarded progression of the injected tumor regardless of whether the tumor is at its early or late stage. Furthermore, it leads to significant inhibition of growth of other, uninjected tumors in the same animal. Capsaicin-elicited immunity is shown to be T cell-mediated and tumor-specific. These results reflect the immunological potency of a neurological ligand in modulating immune response against an established tumor.  相似文献   

7.
BAC is a common pattern in conventional lung adenocarcinoma. In the past, however, there were no well-defined criteria for BAC. As a result, it was difficult to evaluate the prognosis on this type of lung adenocarcinoma. Though the 1999 WHO classification of BAC provides a useful framework, it does not provide detailed enough information to predict prognosis in lung adenocarcinomas with BAC feature. The aim of this study was to address the prognostic value of bronchioloalveolar carcinoma (BAC) component in lung adenocarcinoma. Ninety-one consecutive surgically treated patients with adenocarcinoma exhibiting various degrees of BAC features and complete follow-up records were retrospectively studied. According to the percentage of BAC component designed as less than 50%, 50%-79%, 80%-99%, and 100%, tumors were classified as type I, type II, type III, and type IV respectively. The overall 5-year survival rate was 64.84%. Multivariate analysis revealed that the four classified types are independent prognostic factors (P=0.0008), as is tumor stage (P=0.0000). The 5-year survival rates were 39.29%, 58.82%, 81.25%, 85.71% for the four classified types respectively, and were 88.89% for stage I, 46.15% for stage II, and 23.81% for stage III. However, the size of tumor (>2 cm) was significant only in the univariate analysis (P=0.0275). In the patients with tumor size exceeding 2 cm in diameter, the BAC component was also significant to predict prognosis (p=0.0008). In lung adenocarcinoma, the BAC component may prove to be useful to predict the outcome of the patients, and the percentage of BAC pattern and pathological stage appear to be two independent prognostic factors.  相似文献   

8.
A gradual increase in the level of 2',5'-oligoadenylate synthetase takes place in Friend erythroleukemia cells after a shiftdown in the rate of cell growth. The increase is about 5-fold after entry of cells into the stationary phase of growth, but much higher (25-fold) when reduction in growth accompanies cell differentiation. In the latter case, the enzyme increase is similar to that which can be induced in these cells by exogenous interferon (IFN). The increase in 2',5'-oligoadenylate synthetase was shown to be due to a spontaneous secretion of IFN by the cells themselves: it is completely abolished if antiserum to murine type I IFN is added to the culture medium. In attempts to isolate some of this spontaneously secreted IFN, we show that it is stable at pH 2, not neutralized by antiserum to type II IFN, and that it also differs from the known IFN species induced by Sendai virus in Friend cells. The major component of this spontaneously secreted IFN is 20,000 M(r) and differs from the corresponding virus-induced 20,000-M(r) IFN by its lower affinity for antiserum to type I IFN and its antigenic characterization as beta-murine IFN. The major component of the spontaneous IFN also exhibits a higher ratio of antigrowth to antiviral activity than the Sendai-induced IFNs. We suggest that Friend cells produce this specific type of IFN for the regulation of their growth and differentiation.  相似文献   

9.
From the results obtained in the present work it is concluded that gamma globulin of the 7 S type (γG) which represents the main immunoglobulin component of pig colostrum, differs from serum γG globulin by the presence of another type of polypeptide chain, designed L2; the latter was detected after S-sulfonation in starch gel electrophoresis as the fastest moving component and its immunoelectrophoretic pattern shows the presence of two precipitating components. Preparation of soluble heavy and light chains enabled us to study them imunochemically. The heavy chain is represented by two zones; the fainter one was not detected in comparative analysis of the heavy chain of serum γG globulin. The L1 chain of colostral gamma globulin and the light chain of serum gamma globulin seem to contain three precipitating components, one of which appears due to aging of the chain solution in the presence of glycine. The material from colostrum seems to contain a larger amount of this component than serum. Further it was shown that the component arising in this way is antigenically closely related to the heavy chain.  相似文献   

10.
MRI findings of 13 patients with soft tissue tumors (STT) are presented. There are were abnormalities, such as primary STTs of the hip in 5 patients, the back in 1, and the neck in 1, STT relapses of the hip in 2 and those of the back in 1. Two patients had chronic hip STT hematomas and 1 had hip STT metastatic melanoma. The diagnosis was verified in 11 cases (in 10 cases at surgery and 1 at needle biopsy). MRI makes it possible to define the accurate sizes of the tumor, its structure and relationship to its adjacent tissues, which is important in choosing at treatment policy, the type and scope of a surgical interventions.  相似文献   

11.
Carney complex (CNC) is a multiple neoplasia syndrome that consists of endocrine (thyroid, pituitary, adrenocortical and gonadal), non-endocrine (myxomas, nevi and other cutaneous pigmented lesions), and neural (schwannomas) tumors. Primary pigmented nodular adrenocortical disease (PPNAD) is the most common endocrine manifestation of CNC and the only inherited form of Cushing syndrome known to date. In the search of genes responsible for CNC, two chromosomal loci were identified; one (17q22-24) harbored the gene encoding the type I-alpha regulatory subunit (RIalpha) of protein kinase A (PKA), PRKAR1A, a critical component of the cAMP signaling pathway. Here we review CNC and the implications of this discovery for the cAMP and/or PKA's involvement in human tumorigenesis.  相似文献   

12.
Proteoglycans (PGs) were isolated from yolk sac tumor and chondroitin sulfate large PG (core molecule with a molecular weight congruent to 200,000) and small PG (core molecule with a molecular weight congruent to 50,000) were detected. Immunohistochemical localization of PGs in three yolk sac tumors was investigated using monoclonal antibodies raised against both small and large PGs, which were purified from human ovarian fibroma capsule and a yolk sac tumor, respectively. The localization of large PG was observed to be distinct from that of small PG. A markedly positive reaction for antibody against large PG was observed in myxomatous areas, perivascular and perivesicular portions; hyaline globules were the most intensely reactive. In the areas showing a polyvesicular vitelline tumor pattern, the compact connective tissue stroma consisted of small PGs. It is conceivable that large PGs are synthesized by immature mesenchymal cells and also by epithelial-like cells as a basement membrane component, whereas small PGs are synthesized by mature fibroblastic cells synthesizing collagen. Immunohistochemical localization of other extracellular matrix components (laminin, fibronectin, type I-IV collagen) was also studied in relation to PG localization.  相似文献   

13.
We have reviewed the experimental results which indicate that endogenous type I interferon (IFN) present either constitutively or possibly induced by the tumor plays an important role in limiting the development of transplantable tumors in mice. Thus, treatment with potent polyclonal neutralizing antibodies to IFN alpha/beta markedly enhanced the subcutaneous growth, invasiveness and metastases of xenogeneic tumor cells (uninfected or infected with RNA or DNA viruses) in athymic nude mice; enhanced the intraperitoneal transplantability of six different syngeneic murine tumors in three strains of immunocompetent mice; and completely abrogated the resistance of allogeneic C57Bl/6 (H-2(b)) or C3H (H-2(k)) mice to the multiplication of Friend erythroleukemia cells (H-2(d)) in the liver and spleen resulting in the death of most mice. The mechanisms by which mice respond to the injection of relatively few tumor cells appear to be multiple, to depend on the site of tumor growth, to occur early and prior to an immunologic response. Endogenous type I IFN appears to constitute an essential component of these defense mechanisms enabling the host to restrict tumor growth.  相似文献   

14.
In ECL cell tumors developed in the setting of hypergastrinemic conditions (ECL cell carcinoids type 1 and 2), hypergastrinemia is the dominant agent acting as a promoter in all steps (hyperplasia-dysplasia-neoplasia) of the tumorigenic sequence. In contrast, it apparently lacks transforming properties as shown by the absence of ECL cell carcinoids in patients exposed to hypergastrinemia alone, i.e., those with sporadic Zollinger-Ellison syndrome. The potential transforming factors include: the allelic loss of the MEN-1 suppressor gene in the genetically predisposed MEN-1 patients, an alteration that may induce ECL cell tumors even in the absence of hypergastrinemia; the still unknown factor(s) associated with atrophic corporal gastritis; agents whose role in the induction of human ECL cell tumors is still unclarified, such as basic Fibroblast Growth Factor, human Chorionic Gonadotropin-alpha and Transforming Growth Factor-alpha; and agents having a favoring role on the ECL exposure to mitogens such as BCL-2. No information is currently available on the pathogenesis of gastrin-independent, sporadic ECL cell carcinoids (type 3) or of gastric neuroendocrine carcinomas.  相似文献   

15.
A stochastic analog to a deterministic model describing subpopulation emergence in heterogeneous tumors is developed. The resulting system is described by the Fokker-Planck or forward Kolmogorov equation. A finite element approach for the numerical solution to this equation is described. Four biological and clinical scenarios are simulated (emergence of heterogeneity, exclusion of a subpopulation, and induction of drug resistance in both pure and heterogeneous tumors). The results of the simulations show that the stochastic model describes the same basic dynamics as its deterministic counterpart via a convective component, but that for each simulation a distribution of tumor sizes and mixes can also be derived from a diffusive component in the model. These distributions yield estimates for subpopulation extinction probabilities. The biological and clinical relevance of these results are discussed. Research support provided in part by ACS Grant IN45-Z and ACS PDT 243 B. Research support provided in part by the National Science Foundation under NSF Grant MCS-8504316, and by the Air Force Office of Scientific Research under Contract F49620-86-C-0111.  相似文献   

16.
After human rhinovirus type 2 (HRV-2) attaches to HeLa cells, two types of subviral particles are formed which closely resemble particles produced in vitro by acid or heat. One type of particle contains RNA whereas the second sediments as an empty capsid and is RNA-deficient. Sodium dodecyl sulfate (SDS) at 10(-4) M inhibits the cell-mediated formation of these particles from HRV-2 virions and the ability of HRV-2 to form plaques, but it does not inhibit the formation of plaques by human rhinovirus 14 (HRV-14). SDS also stabilizes HRV-2 against inactivation by acid or heat to a much greater extent than it does HRV-14. In a similar manner, SDS protects against the acid inactivation of the subpopulation of HRV-2 natural top component particles which attach to virus-specific cellular receptors. This suggests that the loss of native properties of natural top component particles and of virion are related processes. The basis for this alteration and also its role in infection are discussed.  相似文献   

17.
Nitric oxide (NO) is involved in retinal signal processing, but its cellular actions are only partly understood. An established source of retinal NO are NOACs, a group of nNOS-expressing amacrine cells which signal onto bipolar, other amacrine and ganglion cells in the inner plexiform layer. Here, we report that NO regulates glutamate responses in morphologically and electrophysiologically identified type 4 OFF cone bipolar cells through activation of the soluble guanylyl cyclase-cGMP-PKG pathway. The glutamate response of these cells consists of two components, a fast phasic current sensitive to kainate receptor agonists, and a secondary component with slow kinetics, inhibited by AMPA receptor antagonists. NO shortened the duration of the AMPA receptor-dependent component of the glutamate response, while the kainate receptor-dependent component remained unchanged. Application of 8-Br-cGMP mimicked this effect, while inhibition of soluble guanylate cyclase or protein kinase G prevented it, supporting a mechanism involving a cGMP signaling pathway. Notably, perfusion with a NOS-inhibitor prolonged the duration of the glutamate response, while the NO precursor L-arginine shortened it, in agreement with a modulation by endogenous NO. Furthermore, NO accelerated the response recovery during repeated stimulation of type 4 cone bipolar cells, suggesting that the temporal response properties of this OFF bipolar cell type are regulated by NO. These results reveal a novel cellular mechanism of NO signaling in the retina, and represent the first functional evidence of NO modulating OFF cone bipolar cells.  相似文献   

18.
Gastric neuroendocrine tumors were originally thought to have a low incidence (three percent). Since endoscopic diagnostic procedures have become clinical routine, they are now found more frequently (relative incidence up to 41 percent). In recent years, classifications have been developed that attempt to consider the biological relevance of these tumors. Four types of gastric neuroendocrine tumor may be distinguished: Type 1 gastric neuroendocrine tumor is most common. It is associated with chronic atrophic fundus gastritis, hypergastrinemia and often with pernicious anemia. Usually it is multicentric and smaller than one cm, does not produce any symptoms and has an excellent prognosis. Type 2 gastric neuroendocrine tumor is second in frequency. It has no association with other diseases, is solitary and has no predilection for a particular localization. It may be larger than 1 cm, produce a carcinoid syndrome or Zollinger-Ellison syndrome and have a metastasis rate of up to 30 percent. Type 3 gastric neuroendocrine tumor is rare and always associated with Zollinger-Ellison syndrome and multiple endocrine neoplasia type I. It occurs as multiple lesions in the gastric body fundus and has a lower metastatic rate than type 2 gastric neuroendocrine tumor. Type 4 gastric neuroendocrine tumor corresponds to a small-cell carcinoma.  相似文献   

19.
Collagen type XI is a component of hyaline cartilage consisting of alpha 1(XI), alpha 2(XI), and alpha 3(XI) chains; with 5-10% of the total collagen content, it is a minor but significant component next to type II collagen, but its function and precise localization in cartilaginous tissues is still unclear. Owing to the homology of the alpha 3(XI) and alpha 1(II) collagen chains, attempts to prepare specific antibodies to native type XI collagen have been unsuccessful in the past. In this study, we report on the preparation and use for immunohistochemistry of a polyclonal antibody specific for alpha 2(XI) denatured collagen chains. The antibody was prepared by immunization with the isolated alpha 2(XI) chain and reacts neither with native type XI collagen nor type I, II, V, or IX by ELISA or immunoblotting, nor with alpha 1(XI) or alpha 3(XI), but with alpha 2(XI) chains. Using this antibody, it was possible to specifically localize alpha 2(XI) in cartilage by pretreating tissue sections with 6 M urea. In double immunofluorescence staining experiments, the distribution of alpha 2(XI) as indicative for type XI collagen in fetal bovine and human cartilage was compared with that of type II collagen, using a monoclonal antibody to alpha 1(II). Type XI collagen was found throughout the matrix of hyaline cartilage. However, owing to cross-reactivity of the monoclonal anti-alpha 1(II) with alpha 3(XI), both antibodies produced the same staining pattern. Cellular heterogeneity was, however, detected in monolayer cultures of human chondrocytes.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

20.
The experiment was conducted to investigate, by using kinematic parameters, the influence of the type of prehension on the transportation component in reaching-grasping movements. The main question was whether the transportation component is influenced by the type of prehension besides the distance of the object. The experiment was carried out on eight subjects who performed reaching-grasping movements toward objects located at different distances. Two types of prehension were examined: whole hand prehension and precision grip. The following kinematic parameters of the transportation component (wrist movement) were studied: movement times, profiles of velocity and accelerations. Our results have shown that the transportation component is affected by the two factors. However the kinematic parameters were influenced differently by the distance and the type of prehension. Our conclusion is that, although distance and type of prehension affect the transportation component, they are computed separately in programming this component.  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