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61.
Fifty-nine Fischer rat tumors and eleven Hooded rat tumors induced by intramuscular injection of Ni3S2 were examined and their histopathologic and cytologic characteristics studied. Nine out of eleven Hooded rat tumors metastasized whereas 15 out of 59 Fischer rat tumors metastasized within 30 days. Histopathological characterization of the Ni3S2-induced tumors was made according to their preponderant cellular constitution. They were grouped into six types: well-differentiated rhabdomyosarcomas, poorly-differentiated rhabdomyosarcomas, embryonal rhabdomyosarcomas, mesenchymal tumors, leiomyosarcoma-like tumors and fibrosarcoma-like tumors. Forty-seven of total of 70 were rhabdomyosarcomas. Tumors with shorter latent periods in Fischer rats and tumors with fleshy and soft texture demonstrated a higher incidence of metastases. 相似文献
62.
HM Agrama JM Blackwood CS Brown GW Machiedo BF Rush 《Canadian Metallurgical Quarterly》1976,132(3):418-421
Various types of drains were inserted into the peritoneal cavity of twenty-eight dogs. After one to seven days, all drains failed to show the presence of 200 cc of colored fluid injected intraperitoneally. On autopsy, all tubes were surrounded and occluded by omentum. 相似文献
63.
A histopathologic study of macular cysts and holes 总被引:1,自引:0,他引:1
Forty-four eyes from 39 patients with either lamellar macular holes (17 eyes), full-thickness macular holes (18 eyes), and/or macular cysts (9 eyes) were studied histopathologically. Lamellar and full-thickness holes were frequently found in eyes with a history of trauma or ocular surgery. Diabetes mellitus was the most common condition associated with macular cysts. Four lamellar holes and four full-thickness holes occurred in eyes with senile macular degeneration. Six lamellar holes, eight full-thickness holes, and one macular cyst developed on an idiopathic basis. Residual cystoid macular edema was the most prevalent accompanying pathologic feature. Cystoid macular edema was also noted in the opposite eye in seven cases of lamellar and full-thickness holes. A preretinal glial membrane, thought to be a secondary change, was found at or near the edges of the lamellar or full-thickness holes or over the macular cyst in the majority of cases. Wrinkling of the internal limiting membrane (ILM) was present in five cases. Vitreous traction, with or without an operculum, was infrequently associated with these entities. 相似文献
64.
The nature of cysteine and cystine uptake from the cerebral capillary lumen was studied in the rat using the carotid injection technique, [35S]-Cysteine uptake was readily inhibited by the synthetic amino acid 2-aminobicyclo(2,2,1)heptane-2-carboxylic acid (BCH), the defining substrate for the leucine-preferring (L) system in the Ehrlich ascites cell. The addition of nonradioactive alanine or serine, representatives of the alanine, serine, and cysteine-preferring (ASC) system, produced no significant decrease in the uptake of cysteine after cysteine transport by the L system was blocked with BCH. This indicated that the major component of cysteine's transport from the brain capillary lumen was by the L system with no detectable uptake of cysteine by the ASC system. No carrier-mediated transport of cystine, the disulfide form of the amino acid, was detected, nor was there any inhibition by cystine of the transport of the neutral amino acid methionine or the basic amino acid arginine. These results suggest that the ASC system, if present, is not quantitatively important for the transport of neutral amino acids from the brain capillary lumen. 相似文献
65.
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67.
Stahl's ear is a congenital malformation of the auricle, which is uncommon in non-Oriental societies. A number of different treatment modalities have been suggested, many of which yield unpredictable results. We review current treatment modalities from the English literature and describe a novel, simple surgical method of repair. First, a helical rim incision is made to expose the abnormal third crus and upper pole of the ear. The third crus is excised as a narrow wedge of cartilage and posterior skin, and the defect is closed primarily. The free third crus cartilage is then grafted onto the scaphal cartilage in an anatomically correct position to form a superior crus. The anterior skin flap is redraped and bolstered over this graft. Only a very small scar on the helical rim remains visible anteriorly. 相似文献
68.
Structural studies on an inhibitory antibody against Thermus aquaticus DNA polymerase suggest mode of inhibition 总被引:1,自引:0,他引:1
Murali R; Helmer-Citterich M; Sharkey DJ; Scalice ER; Daiss JL; Sullivan MA; Krishna Murthy HM 《Protein engineering, design & selection : PEDS》1998,11(2):79-86
TP7, an antibody against Thermus aquaticus DNA polymerase I (TaqP), is used
as a thermolabile switch in 'hot start' variations of PCR to minimize
non-specific amplification events. Earlier studies have established that
TP7 binds to the polymerase domain of TaqP, competes with primer template
complex for binding and is a potent inhibitor of the polymerase activity of
TaqP. We report crystallographic determination of the structure of an Fab
fragment of TP7 and computational docking of the structure with the known
three-dimensional structure of the enzyme. Our observations strongly
suggest that the origin of inhibitory ability of TP7 is its binding to
enzyme residues involved in DNA binding and polymerization mechanism.
Although criteria unbiased by extant biochemical data have been used in
identification of a putative solution, the resulting complex offers an
eminently plausible structural explanation of biochemical observations. The
results presented are of general significance for interpretation of docking
experiments and in design of small molecular inhibitors of TaqP, that are
not structurally similar to substrates, for use in PCR. Structural and
functional similarities noted among DNA polymerases, and the fact that
several DNA polymerases are pharmacological targets, make discovery of
non-substrate based inhibitors of additional importance.
相似文献
69.
HM Cox 《Canadian Metallurgical Quarterly》1997,3(4):218-223
This paper describes one aspect of a study into the experiences in long-term healing of a community following the 1983 Ash Wednesday bushfire. Forty participants were interviewed, of whom 26 were residents and 14 disaster relief workers. The paper concentrates on the experiences of the latter, describing how they came to understand the bushfire affected the community and how they managed disaster work. For novices it was a profoundly difficult experience, for which they received little help and had to manage with whatever skill they drew on in their 'normal' working lives, mixed with a good deal of intuition. The paper suggests that health workers in vulnerable areas require preparation for a likely disaster; that 'outsiders' need to deal through existing community groups and individuals to gain access to those in need of their skills, and that they also require preparation for helping 'insiders' who are themselves victims of the catastrophe. 相似文献
70.
HM Sansbury AE Wisehart-Johnson C Qi S Fulwood KE Meier 《Canadian Metallurgical Quarterly》1997,18(9):1817-1824
Phorbol ester-sensitive EL4 murine thymoma cells respond to phorbol 12-myristate 13-acetate with activation of ERK mitogen-activated protein kinases, synthesis of interleukin-2, and death, whereas phorbol ester-resistant variants of this cell line do not exhibit these responses. Additional aspects of the resistant phenotype were examined, using a newly-established resistant cell line. Phorbol ester induced morphological changes, ERK activation, calcium-dependent activation of the c-Jun N-terminal kinase (JNK), interleukin-2 synthesis, and growth inhibition in sensitive but not resistant cells. A series of protein kinase C activators caused membrane translocation of protein kinase C's (PKCs) alpha, eta, and theta in both cell lines. While PKC eta was expressed at higher levels in sensitive than in resistant cells, overexpression of PKC eta did not restore phorbol ester-induced ERK activation to resistant cells. In sensitive cells, PKC activators had similar effects on cell viability and ERK activation, but differed in their abilities to induce JNK activation and interleukin-2 synthesis. PD 098059, an inhibitor of the mitogen activated protein (MAP)/ERK kinase kinase MEK, partially inhibited ERK activation and completely blocked phorbol ester-induced cell death in sensitive cells. Thus MEK and/or ERK activation, but not JNK activation or interleukin-2 synthesis, appears to be required for phorbol ester-induced toxicity. Alterations in phorbol ester response pathways, rather than altered expression of PKC isoforms, appear to confer phorbol ester resistance to EL4 cells. 相似文献