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101.
Collision tumour of the oesophagus: a challenge for histological diagnosis. 总被引:2,自引:0,他引:2 下载免费PDF全文
An unusual case of mantle cell lymphoma metastasising to squamous cell carcinoma of the oesophagus, in a 62 year old Chinese man, is reported. A histological diagnosis based on examination of a small endoscopic biopsy specimen, in the absence of detailed clinical information, may be difficult, as the lymphoma component can be mistaken for reactive lymphoid infiltrate which is sometimes present adjacent to squamous cell carcinoma. Correlation with the clinical history, careful assessment of the subtle histological changes, and use of ancillary methods such as immunohistochemistry are most helpful in making the correct diagnosis. This case also illustrates further the possible occurrence of lymphomatous infiltrates surrounding other lesions in patients with a previous or concurrent history of lymphoma. 相似文献
102.
Timothy A. Jennings MD Ng Bernard MD Ann Boguniewicz MD Muzaffar Khan MD Donald Rice MD James Figge MD 《Endocrine pathology》1998,9(4):353-361
Hemorrhagic adrenal pseudocysts are uncommon nonneoplastic lesions that have been reported as secondary to intraparenchymal
hemorrhage or alternatively related to endothelial (vascular) cysts. Ultrastructural and immunohistochemical evidence in support
of the latter has been presented, but the exact nature of hemorrhagic adrenal pseudocysts remains poorly defined. We evaluated
six surgical specimens of hemorrhagic adrenal pseudocysts using immunohistochemical staining for CD31 and CD34, as well as
conventional histochemistry. All six cases had hemorrhagic contents within a wall of variable thickness possessing focal areas
of linear, disrupted elastin, and smooth muscle. Three cases demonstrated extensive thrombosis with organization, including
papillary endothelial hyperplasia, simulating angiosarcoma. In these cases, CD31 and CD34 staining decorated areas of papillary
endothelial hyperplasia as well as foci of the internal cyst lining, whereas the other cases were negative for both antibodies.
Of interest is the history of FNA prior to surgical resection in three cases of hemorrhagic adrenal pseudocysts, two of which
showed papillary endothelial hyperplasia. The presence of papillary endothelial hyperplasia and our immunohistochemical findings
support, the conclusion that adrenal pseudocysts are posthemorrhagic and derive from vascular disruption. Furthermore, FNA
or other interventional studies may be associated with papillary endothelial hyperplasia in hemorrhagic adrenal pseudocysts. 相似文献
103.
Y chromosome microdeletions, in azoospermic or near-azoospermic subjects, are located in the AZFc (DAZ) subregion 总被引:9,自引:2,他引:9
Submicroscopic deletions of the Y chromosome and polymorphisms of the
androgen receptor (AR) gene in the X chromosome have been observed in men
with defective spermatogenesis. To further define the subregions/genes in
the Y chromosome causing male infertility and its relationship to
polymorphisms of the AR polyglutamine tract, we screened the genomic DNA of
202 subfertile males and 101 healthy fertile controls of predominantly
Chinese ethnic origin. Y microdeletions were examined with 16
sequence-tagged site (STS) probes, including the RBM and DAZ genes,
spanning the AZFb and AZFc subregions of Yq11, and related to the size of
trinucleotide repeat encoding the AR polyglutamine tract. Y microdeletions
were detected and confirmed in three out of 44 (6.8%) of azoospermic and
three out of 86 (3.5%) severely oligozoospermic patients. No deletions were
detected in any of the patients with sperm counts of >0.5 x 10(6)/ml,
nor in any of the 101 fertile controls. All six affected patients had
almost contiguous Y microdeletions spanning the entire AZFc region
including the DAZ gene. The AZFb region, containing the RBM1 gene, was
intact in five of the six subjects. Y deletions were not found in those
with long AR polyglutamine tracts. Our study, the first in a Chinese
population, suggest a cause and effect relationship between Y
microdeletions in the AZFc region (possibly DAZ), and azoospermia or
near-azoospermia. Y microdeletions and long AR polyglutamine tracts appear
to be independent contributors to male infertility.
相似文献
104.
Fertility clinics worldwide routinely produce a large volume of 'waste' follicular aspirate, which is potentially an abundant source of immature ovarian follicles. Current attempts to cultivate these further in vitro to yield viable mature oocytes for fertility treatment have not yet achieved much success. Instead, recent lines of evidence have emerged that are suggestive of a potential stem cell niche within such immature ovarian follicles. The recent discovery of follicular renewal and putative germ-line stem cells within the postnatal mammalian ovary shook the foundations of reproductive biology by challenging the established dogma that mammalian females lose the capacity for germ cell renewal during fetal life, such that a fixed reserve of germ cells (oocytes) enclosed within follicles is endowed at birth. More intriguingly, another recent study in the Drosophila model provided compelling evidence that somatic progenies (nurse cells) of germ-line stem cells had the ability to revert back to the stem-cell-like state. This introduces the exciting possibility that within the mammalian ovarian follicle, similar somatic progenies of germ-line stem cells may also possess a greater intrinsic ability to revert back into functional stem cells. If this is the case, then a favored candidate would be the cumulus/granulosa of immature ovarian follicles, since such cells are true homologues of nurse cells found within the Drosophila ovary. The successful elucidation of a human germ-line stem cell niche within immature ovarian follicles is likely to have huge ramifications in stem cell biology and regenerative medicine. 相似文献
105.
BACKGROUND: Impaired implantation in assisted reproduction cycles with high serum estradiol (E(2)) concentrations may be related to suboptimal endometrial perfusion. Endometrial and subendometrial blood flow were compared between excessive responders (serum E(2) on the day of HCG >20 000 pmol/l) and moderate responders (E(2) < or =20 000 pmol/l). METHODS: Three-dimensional (3D) ultrasound examination with power Doppler was performed 2, 4 and 7 days after HCG in 32 patients who did not have embryo transfer in order to measure endometrial thickness, pulsatility index (PI)/resistance index (RI) of uterine vessels, and endometrial volume, vascularization index (VI)/flow index (FI)/vascularization flow index (VFI) of endometrial and subendometrial regions. RESULTS: Excessive responders tended to have lower endometrial and subendometrial VI/VFI on HCG +2 and more absent endometrial/subendometrial blood flow. They had significantly higher endometrial FI and subendometrial VFI than moderate responders on HCG +7. Only in the excessive responder group, uterine PI/RI declined significantly from HCG +2 to HCG +7 and endometrial VI/VFI increased significantly from HCG +4 to HCG +7. CONCLUSION: Changes in uterine Doppler flow indices, and endometrial and subendometrial 3D power Doppler flow indices during the early luteal phase were significantly different between moderate and excessive responders. 相似文献
106.
Multipotent, self-renewing stem and progenitor cells isolated from the mammalian central nervous system (CNS) have been shown to survive as allografts following transplantation to sites throughout the neuraxis. However, studies of this type shed little light upon the immunologic properties of the cells themselves, primarily because little is learned about the intrinsic immunogenic properties of a cell when it is grafted into an immune-privileged site. We have therefore investigated the immunogenic and antigenic properties of CNS progenitor cells by grafting them into a conventional (i.e., non-immune-privileged) site, namely, beneath the kidney capsule. Our results indicate that allogeneic CNS progenitor cells survive at least 4 weeks in a conventional site, during which time they neither sensitize their hosts nor express detectable levels of major histocompatibility complex (MHC) class I or II. These in vivo data are in accord with flow cytometric results showing that CNS progenitor cells do not express MHC class I or class II, either at baseline or upon differentiation in 10% serum. Exposure to interferon gamma, however, reversibly upregulates expression of these key transplantation antigens. Together, these results reveal CNS progenitor cells to possess inherent immune privilege. Since CNS progenitor cell allografts were rejected beneath the kidney capsule following specific sensitization of the host, CNS progenitor cells were able to display alloantigens, albeit not in an immunogenic form. 相似文献
107.
Using an FT 60 schedule, rats on 100% free feeding tested in the dark phase of a 12:12 light-dark cycle were trained to self-administer ethanol intravenously. The effect was dose-dependent with 20% ethanol being the preferred dose as measured by the number of infusions. Daily administration of 1.5 mg/kg melatonin significantly increased ethanol self-injection in the dark but not in the light. The time of day of testing and/or drug administration may be an important variable in studies on self-administration of drugs. Testing in the dark may eliminate the need for reducing body weight when inducing self-administration of ethanol. 相似文献
108.
Various investigators have used the monodomain model to study cardiac propagation behaviour. In many cases, the governing
non-linear parabolic equation is solved using the finite-difference method. An adequate discretisation of cardiac tissue with
realistic dimensions, however, often leads to a large model size that is computationally demanding. Recently, it has been
demonstrated, for a two-dimensional homogeneous monodomain, that the Chebyshev pseudospectral method can offer higher computational
efficiency than the finite-difference technique. Here, an extension of the pseudospectral approach to a three-dimensional
inhomogeneous case with fibre rotation is presented. The unknown transmembrane potential is expanded in terms of Chebyshev
polynomial trial functions, and the monodomain equation is enforced at the Gauss-Lobatto node points. The forward Euler technique
is used to advance the solution in time. Numerical results are presented that demonstrate that the Chebyshev pseudospectral
method offered an even larger improvement in computational performance over the finite-difference method in the three-dimensional
case. Specifically, the pseudospectral method allowed the number of nodes to be reduced by ≈85 times, while the same solution
accuracy was maintained. Depending on the model size, simulations were performed with ≈18–41 times less memory and ≈99–169
times less CPU time. 相似文献
109.
110.