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81.
 The recently identified prostate cancer susceptibility gene ELAC2 (HPC2) harbors two common missense variants, a serine to leucine substitution at residue 217 (Leu217) and an alanine to threonine substitution at residue 541 (Thr541). We genotyped the two variants in a Japanese cohort consisting of 350 prostate cancer patients 242 male population controls, and 114 male low-risk controls. Both missense alleles, Leu217 and Thr541, were carried at higher frequency in Japanese patients than in the controls (Leu217, P = 0.0012; Thr541, P = 0.0145), and the odds ratios associated with carrying these sequence variants were higher in Japanese than in Caucasians. Although the Leu217 and Thr541 variants of ELAC2 are less common in Japanese than in Caucasians, both variants confer significantly increased risk of prostate cancer in Japanese. Carriage of these variants was not associated with age at diagnosis, tumor stage, or tumor grade in these Japanese prostate cancer patients. The allele-specific pattern of risk observed in Japanese and familial Caucasian patients was qualitatively similar; however, the magnitude of that risk was considerably greater in Japanese than in Caucasians. Received: September 3, 2002 / Accepted: October 2, 2002  相似文献   
82.
Reactions of N-carboxy-α-amino acid anhydride (NCA) with dialkylzinc or related organozinc compounds were studied to elucidate the polymerization mechanism of NCA by dialkylzinc as initiator. The first stage of initiation reaction is a hydrogen abstraction reaction of dialkylzinc from NH group of α-amino acid NCA resulting in the formation of an activated NCA. The second stage of initiation is a reaction between two molecules of the activated NCA forming a zinc carbamate group. Propagation reaction is a carbonyl addition of the zinc carbamate group to the activated NCA to form a mixed anhydride which changes into an amide group releasing carbon dioxide. Regeneration of the activated NCA is supposed to be done by the reaction of free α-amino acid NCA with the zinc atom bonded to nitrogen atom at the growing chain end.  相似文献   
83.
84.
The copolymerization of N-carboxy-L(+)-alanine anhydride (L(+)-alanine NCA) with DL-propylene oxide was examined using diethylzinc or triethylaluminum as catalysts. Analytical data, IR and NMR-spectra indicate that dioxane soluble copolymers contain various kinds of linkage such as amide, ester, ether, and urethane in their polymer chains. Optical rotatory dispersion curves of the copolymers measured in benzene or chloroform were analyzed in terms of the one term DRUDE equation and of the MOFFITT-YANG equation. The copolymerization of L(-)-β-phenylallanine NCA with DL-propylene oxide was also examined. The sign of the optical rotation of the copolymer prepared with diethylzinc catalyst was opposite to that of the copolymer prepared with triethylaluminum.  相似文献   
85.
The gene Bcl11b, which encodes zinc finger proteins, and its paralog, Bcl11a, are associated with immune-system malignancies. We have generated Bcl11b-deficient mice that show a block at the CD4-CD8- double-negative stage of thymocyte development without any impairment in cells of B- or gammadelta T cell lineages. The Bcl11b-/- thymocytes showed unsuccessful recombination of V(beta) to D(beta) and lacked the pre-T cell receptor (TCR) complex on the cell surface, owing to the absence of Tcrb mRNA expression. In addition, we saw profound apoptosis in the thymus of neonatal Bcl11b-/- mice. These results suggest that Bcl11b is a key regulator of both differentiation and survival during thymocyte development.  相似文献   
86.
An implantable secondary battery is one of the key components in a total artificial heart system. Because a 2 year cycle life is required, the cycle life of the secondary battery as well as its charge and discharge properties are important parameters for selection of an appropriate battery. We carried out cycle life tests on four kinds of rechargeable batteries (a Ni-MH secondary battery, a Ni-Cd secondary battery, a Li-ion battery with a graphite anode, and a Li-ion battery with a nongraphitizable carbon electrode) to determine their suitability as implanted back-up batteries. Each of the batteries was charge/discharge cycled at 37 degrees C to 39 degrees C using a charge current of 1 C ampere, and they were each fully discharged under either pulsatile discharge loads, which mimicked pulsatile operation, or a nonpulsatile load equivalent to the average of the pulsatile loads. The two Li-ion batteries made by different manufacturers both met the minimum requirement of cycle life of more than 1,500 cycles, considering safety coefficient regardless of the discharge pattern. In addition, the temperature increase of these Li-ion batteries (3 degrees C) was lower than that of Ni-Cd and Ni-MH batteries (15-25 degrees C). Out of these four batteries, the two Li-ion batteries are the most suitable for use in a totally implantable artificial heart system.  相似文献   
87.
Effects of dietary iodine on chemical induction of thyroid carcinoma   总被引:1,自引:0,他引:1  
Effects of dietary iodine on the induction of thyroid carcinoma using N-nitrosobis(2-hydroxypropyl)amine (BHP) were studied. Male Wistar rats were fed with an iodine-adequate diet (IAD group), an iodine-rich diet (IRD group) and an iodine-deficient diet (IDD group), respectively, until the time of sacrifice. From the 2nd experimental month, animals were injected with BHP once a week for 10 weeks. In the IAD and IRD groups, benign nodules and papillary carcinoma were found. The incidence of rats with benign nodules was 100% in both groups and animals with papillary carcinoma in the IAD and IRD groups comprised 33% and 29%, respectively. The area of the thyroid gland occupied by nodular lesions was much narrower in the IRD group than in the IAD group. In the IDD group, the thyroid showed marked enlargement due to multiple nodular proliferation of follicle cells. The incidence of rats with carcinoma was 100%, and not only papillary but also follicular carcinoma and one pulmonary metastasis were found. As the iodine content of the diet decreased, the nodular lesions increased in width and number, and the incidence of carcinoma in rats became higher. These effects of dietary iodine are probably related to the goitrogenic and/or promoting effects of TSH.  相似文献   
88.
We studied seven cases of malignant neoplasms, taken from various sites in the body, that were associated with marked granulocytosis. The seven cases were characterized clinically by marked granulocytosis with mature neutrophils, nonspecific inflammatory signs, and a rapid and progressive fatal course of the disease. The elevation of granulocyte count generally paralleled the increase in tumor size. Postmortem examination revealed no evidence of extensive bone marrow metastases or significant suppuration in any case. The bone marrows showed varying degrees of granulocytic hyperplasia with or without a shift to the left in the maturation series. Erythroid cell hyperplasia was observed in some cases, and in one instance there was an increase in immature eosinophils. The spleen showed various degrees of infiltration by neutrophils, from minimal to extremely marked; some spleens had foci of extramedullary hemopoiesis. Colony-stimulating activity was demonstrated in tumor extracts from three of these cases and from the serum in another case. Thus, it is suggested that marked granulocytosis in these patients was caused, at least in part, by colony-stimulating factor produced by the neoplastic cells.  相似文献   
89.
After left nephrectomy, 3 10-week old NZB/W mice received orthotopic grafts of kidneys from parental NZW mice of the same age. At autopsy conducted at the age of 33-38 weeks, glomerulonephritis of similar extent was noted in the recipients' own and in the grafted kidneys. Also, very similar granular deposits of immunoglobulins and complement were demonstrated in these kidneys. It was concluded that the absence of glomerulonephritis in NZW mice cannot be attributed to the refractoriness of their kidney to this disease.  相似文献   
90.
AIMS: Human chorionic gonadotrophin (hCG) is a useful marker for chorionic proliferative disorders, such as choriocarcinoma. Although hCG synthesis in lung cancers is frequent, primary pulmonary choriocarcinoma (PCC) is rare. To clarify the differences between primary choriocarcinoma and hCG-producing giant cell carcinoma (GCC) of the lung, we compared the clinicopathological and immunohistochemical findings of these tumours. METHODS AND RESULTS: Three patients, one with PCC and two with hCG-producing GCC, were included in this study. They were all middle-aged men and habitual smokers. The growth of these tumours and the progression of the clinical courses were extremely rapid, and the patients all died within 8 months after the pulmonary tumours were found. Haemorrhagic appearance was a common macroscopic feature of the specimens obtained. Microscopically, both types of tumours mainly consisted of atypical polygonal cells. While PCC contained many syncytial trophoblast-like multinucleated cells that had strong immunoreactivity for anti-hCG, such cells were relatively few in hCG-producing GCC. These histological and immunohistochemical findings reflected the serum test result for hCG, which was higher in the case of PCC. CONCLUSIONS: There are a few differences between PCC and hCG-producing GCC, as described above. Reliable distinction between them seems to be difficult for pathologists and worthless for clinicians.  相似文献   
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