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1.
2.
Effects of cigarette smoke dose and time after smoke exposure on uptake of asbestos fibers by rat tracheal epithelial cells 总被引:3,自引:0,他引:3
A Churg J Hobson J Wright 《American journal of respiratory cell and molecular biology》1990,3(3):265-269
We have previously shown that exposure of excised rat tracheal segments to cigarette smoke followed by exposure to a solution of amosite asbestos increases uptake of asbestos fibers compared to exposure to air followed by asbestos. To learn more about the mechanism of smoke-enhanced fiber uptake, we evaluated the effects of amount of smoke and time delay between smoke exposure and asbestos exposure on fiber penetration into the epithelium. To determine whether amount of smoke exposure affected this process, we exposed tracheal segments to 1, 3, or 6 puffs of smoke and subsequently to 5 mg/ml amosite asbestos for 1 h. The segments were then maintained in organ culture for up to 7 d. Asbestos uptake was evaluated by counting fibers in the epithelium by light microscopy. Exposure to increasing numbers of puffs of smoke produced a dose-related increase in fiber uptake at 1 d, 3 d, and 7 d after exposure. To determine whether asbestos exposure needed to occur immediately after smoke exposure for enhanced uptake of fibers to occur, we exposed tracheal segments to 6 puffs of smoke and then delayed exposure to asbestos for 0 (immediate exposure), 3, 18, or 48 h. Tracheas were again maintained in organ culture for up to 7 d after asbestos exposure. Delayed exposure to asbestos after 6 puffs of smoke produced an increase in fiber uptake, even with an interval as long as 48 h between smoke and asbestos exposure; however, the absolute magnitude of fiber uptake was less than that seen with immediate postsmoke asbestos exposure. If catalase was added to the asbestos solution, the smoke-enhanced uptake was abolished, no matter what the time delay.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
3.
Fibrillary renal deposits and nephritis. 总被引:3,自引:1,他引:3
J. L. Duffy E. Khurana M. Susin G. Gomez-Leon J. Churg 《The American journal of pathology》1983,113(3):279-290
Fibrillary renal deposits and nephritis. The authors have studied 8 patients whose glomeruli contain abundant fibrils in their mesangial matrix and basement membranes. Although the location of these fibrils is very similar to that of amyloid, they are about twice the size of amyloid fibrils, averaging 20 nm in width, and fail to react as amyloid does with special stains. Immunofluorescence-microscopic studies are usually positive with antiserums to IgG, often IgM, and in some cases IgA, and also kappa and lambda light chains, C3, and C4. The fibrils are associated with diffuse mesangial widening and increased mesangial matrix strands. Although peripheral glomerular capillary walls appear to be spared initially, their eventual involvement leads to glomerular capillary collapse and glomerular obsolescence. Crescent formation occurred in 5 cases, focally in 3 and diffusely in 2. Tubular basement membrane involvement was seen in 1 case. These patients exhibit hematuria, and proteinuria, and often hypertension and renal insufficiency. Proteinuria was in the nephrotic range in 3 patients in whom involvement of glomerular capillary basement membranes was extensive. Unless electron microscopy is applied to renal biopsies, these cases may be considered to represent mesangiocapillary or rapidly progressive glomerulonephritis, or amyloidosis. The nature of these fibrils is as yet not determined. It is likely that they have been called "atypical amyloidosis" in the past. 相似文献
4.
Histochemical Distribution of Carbonic Anhydrase After Ligation of the Pancreatic Duct 总被引:2,自引:0,他引:2
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The distribution of carbonic anhydrase in the exocrine pancreas of the rat has been examined during the first 3 weeks after duct ligation. The normal pattern of positive reaction in ducts, centroacinar cells and capillaries changed, by the end of the first week, to one in which all the cells in the dilated ducts showed the enzyme. This situation persisted through the third week. By electron microscopy, the enzyme was found on the apical membranes of ductular, centroacinar and acinar cells, as well as on the surface membranes of the modified cells seen at 1 week. The significance of these findings with respect to function and cell origin is discussed. 相似文献
5.
Hydrosalpinges adversely affect markers of endometrial receptivity 总被引:22,自引:10,他引:22
Meyer WR; Castelbaum AJ; Somkuti S; Sagoskin AW; Doyle M; Harris JE; Lessey BA 《Human reproduction (Oxford, England)》1997,12(7):1393-1398
While in-vitro fertilization (IVF) was initially developed in women with
tubal factor infertility, recent clinical studies have suggested that the
presence of hydrosalpinges lowers implantation and pregnancy rates. We
postulated that these hydrosalpinges cause impaired endometrial
receptivity. A total of 103 women with hydrosalpinges were prospectively
evaluated, and compared with 55 infertile and 44 fertile controls. All
women had endometrial biopsies during the window of implantation, analysed
by conventional histological criteria, and also stained for three integrin
markers of endometrial receptivity (alpha1beta1, alpha4beta1 and alpha
vbeta3). Women with hydrosalpinges (cases) expressed significantly less of
the alpha vbeta3 integrin compared with controls. There was no difference
in expression of alpha1beta1 or alpha4beta1 among groups. A significantly
greater number of cases had out of phase histology and missing alpha vbeta3
(type I defects) and absent integrin expression despite normal histological
maturation (type II) defects, compared with controls. Of 20 women with
impaired endometrial receptivity who were also biopsied after hydrosalpinx
surgery, 70% demonstrated increased alpha vbeta3 expression. Seventy-seven
percent of type I and 57% of type II defects were corrected
postoperatively. Using markers of endometrial receptivity, this study
demonstrates that inflammatory hydrosalpinges have an adverse effect on
endometrial receptivity, which in some cases may be overcome by surgical
treatment of the hydrosalpinx.
相似文献
6.
A case of infantile digital fibromatosis was studied by light and electron microscopic histochemistry. Using two different acidic solutions of phosphotungstic acid at varying pHs, the round inclusions characteristic of this tumor were shown to have a high protein content with little or no carbohydrate. The histochemical reactivity of the inclusions was similar to that of the cytoplasmic microfibrils in the tumors cells and consistent with the idea that both the inclusions and the microfibrils represent actin. There is, however, no definite proof that the tumor cells are myofibroblasts. At the present time, this tumor should be viewed as a peculiar expression of deranged assembly or metabolism of filamentous proteins or both. 相似文献
7.
bcl-2 transgene expression promotes survival and reduces proliferation of CD3-CD4-CD8- T cell progenitors 总被引:16,自引:0,他引:16
Proliferative expansion and apoptotic cell death play prominent roles in T
cell development. The molecular control of cell cycle progression and
apoptosis appear to be inter-connected since the Bcl-2 protein can inhibit
apoptosis and slow cell cycle progression in cortical thymocytes and mature
T cells, particularly during the transition from the quiescent state into
the cell cycle. Here the impact of bcl-2 transgene expression on
CD3-CD4-CD8- T cell progenitors was assessed. Bcl-2 enhanced the survival
of these progenitors at all of the four major differentiation stages, CD25-
CD44+ (pro-T1), CD25 + CD44+ (pro- T2), CD25 + CD44- (pro-T3) and
CD25-CD44- (pro-T4). However, it reduced cell cycling and slowed turnover
only in the pro-T4 subset. From an analysis of bcl-2 transgenic mice
expressing a TCR transgene or bearing a mutation in the scid or rag-1 gene
we conclude that Bcl-2 inhibits proliferation only of T cell progenitors
that are activated via the pre- TCR, not those stimulated via c-Kit and the
IL-7 receptor.
相似文献
8.
Mutations in the Ca(2+)-sensing receptor gene cause autosomal dominant and sporadic hypoparathyroidism 总被引:3,自引:0,他引:3
Baron J; Winer KK; Yanovski JA; Cunningham AW; Laue L; Zimmerman D; Cutler GB Jr 《Human molecular genetics》1996,5(5):601-606
Parathyroid hormone secretion is negatively regulated by a 7- transmembrane
domain, G-protein coupled Ca(2+)-sensing receptor. We hypothesized that
activating mutations in this receptor might cause autosomal dominant
hypoparathyroidism (ADHP). Consistent with this hypothesis, we identified,
in two families with ADHP, heterozygous missense mutations in the
Ca(2+)-sensing receptor gene that cosegregated with the disorder. None of
50 normal controls had either mutation. We also identified a de novo,
missense Ca(2+)-sensing receptor mutation in a child with severe sporadic
hypoparathyroidism. The amino acid substitution in one ADHP family affected
the N-terminal, extracellular domain of the receptor. The other mutations
involved the transmembrane region. Unlike patients with acquired
hypoparathyroidism, patients with these mutations had hypercalciuria even
at low serum calcium concentrations. Their greater hypercalciuria
presumably reflected activation of Ca(2+)-sensing receptors in kidney
cells, where the receptor negatively regulates calcium reabsorption. This
augmented hypercalciuria increases the risk of renal complications and thus
has implications for the choice of therapy.
相似文献
9.
Idiopathic and secondary vasculitis: a review 总被引:5,自引:0,他引:5
10.
Carcinoembryonic antigen and milk-fat globule protein staining of malignant mesothelioma and adenocarcinoma of the lung 总被引:2,自引:0,他引:2
Immunohistologic markers have been of considerable value in differentiating malignant mesothelioma from adenocarcinoma. Recently, staining for milk-fat globule (MFG) protein has been suggested as a useful diagnostic test for this separation, but subsequent reports have been conflicting, with some authors finding clearcut differences, while others showed similar marking of both tumor types. To examine this technique further, we studied lung carcinomas and mesotheliomas with commercially available anti-MFG, and compared these results with those obtained with anticarcinoembryonic antigen (CEA), a commonly used immunomarker of carcinoma. We found that carcinomas showed strong cytoplasmic staining for MFG and CEA; however, a greater percentage of carcinomas were more strongly positive for CEA than for MFG. Mesotheliomas did not, for the most part, stain strongly with either antibody. In addition, carcinomas from different hospitals stained differently for MFG, but not for CEA. We conclude that although strong cytoplasmic staining for MFG is a reasonably reliable indicator of carcinoma, CEA staining provides a better separation and is considerably easier to interpret in lung cancer specimens. 相似文献