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921.
5'-Deoxy-5'-fluoro-O4-methylthymidine was synthesized by the reaction of the corresponding 5'-O-tosylate with KF in the presence of Kryptofix [222] and coupled to a 5'-phosphoramidite-activated CPG-bound oligodeoxynucleotide. The sequence of reactions and purifications were accomplished within 4 h, a necessary condition of the development of radiofluorinated antisense oligodeoxynucleotide probe for use with PET.  相似文献   
922.
Comparison of the binding properties of non-glycosylated, glycosylated human leukemia inhibitory factor (LIF) and monoclonal antibodies (mAbs) directed at gp190/LIF-receptor beta subunit showed that most of the low affinity (nanomolar) receptors expressed by a variety of cell lines are not due to gp190. These receptors bind glycosylated LIF produced in Chinese hamster ovary cells (CHO LIF) (Kd = 6.9 nM) but not Escherichia coli-derived LIF or CHO LIF treated with endoglycosidase F. CHO LIF binding to these receptors is neither affected by anti-gp190 mAbs nor by anti-gp130 mAbs and is specifically inhibited by low concentrations of mannose 6-phosphate (Man-6-P) (IC50 = 40 microM), suggesting that they could be related to Man-6-P receptors. The identity of this LIF binding component with the Man-6-P/insulin-like growth factor-II receptor (Man-6-P/IGFII-R) was supported by several findings. (i) It has a molecular mass very similar to that of the Man-6-P/IGFII-R (270 kDa); (ii) the complex of LIF cross-linked to this receptor is immunoprecipitated by a polyclonal anti-Man-6-P/IGFII-R antibody; (iii) this antibody inhibits LIF and IGFII binding to the receptor with comparable efficiencies; (iv) soluble Man-6-P/IGFII-R purified from serum binds glycosylated LIF (Kd = 4.3 nM) but not E. coli LIF. The potential role of Man-6-P/IGFII-R in LIF processing and biological activity is discussed.  相似文献   
923.
An enantioselective synthesis of the (1'S,2'R)-dimethylheptyl cannabinoid side chain has been developed and employed in the synthesis of 11-hydroxy-(1'S,2'R)-dimethylheptyl-delta 8-THC (3). Pharmacology, in vivo and in vitro, indicate (3) to be one of the most potent traditional cannabinoids known.  相似文献   
924.
This paper describes a rapid, specific and sensitive multiresidue method for the routine analysis of several classes of pesticides used for the treatment of apples and pears, involving a rapid extraction procedure at pH 4.5 with a mixture of acetone-dichloromethane-hexane (50:20:30, v/v/v) and gas chromatography coupled to mass-selective detection, in order to achieve quantitative analysis down to their respective maximum residue limit. Extraction recoveries were between 55 and 98%. Limits of detection and limits of quantitation ranged respectively, from 0.01 to 0.05 mg/kg and from 0.02 to 0.1 mg/kg. Intra-assay relative standard deviation was less than 19% for all compounds. An excellent linearity was observed from these LOQs up to 500 mg/kg. Intermediate (inter-assay) precision and accuracy were satisfactory. The method has been applied to many fruit samples intended for commercialisation.  相似文献   
925.
INTRODUCTION: The technologic improvement of surface coils in MRI has allowed better visualization of the skin and thus permitted the clinical use of this technique in dermatology. MRI allows to assess the depth and extent of skin tumors and to detect any malignant transformation. The MR differentiation between benign and malignant skin lesions relies on morphological criteria which however do not have an absolute diagnostic value. We investigated the role of paramagnetic contrast agents in the differentiation between benign and malignant skin lesions. MATERIAL AND METHODS: Forty-one patients, 33 with benign and 8 with malignant skin tumors, were submitted to MRI. All the examinations were performed with a 1.5 T superconductive unit, with a 2.5 cm surface coil. Axial T1- and T2-weighted SE images were acquired with 2 mm slice thickness. Paramagnetic contrast material was administered to all patients. The signal intensity of the skin lesions was calculated before and after paramagnetic contrast agent administration positioning a region of interest. A percentage ratio of contrast enhancement was calculated to quantify contrast agent uptake and the relative values were compared between benign and malignant lesions. A qualitative analysis was also performed rating the contrast enhancement of each lesion as high, intermediate, or absent. RESULTS: The quantitative analysis showed a statistically significant difference (p < .5) between the contrast enhancement values of benign and malignant lesions. In particular, malignancies had values ranging 117.3 (+/- 28.7) to 125 (+/- 32.4), while benign lesions had -20.6 to 99.8 (+/- 21.1). Conversely, no difference in contrast enhancement was found at qualitative analysis. CONCLUSIONS: MRI is a promising tool for characterizing skin tumors. Our preliminary results should be confirmed on larger series of patients with the use of high temporal resolution imaging sequences.  相似文献   
926.
This study examined the effects of weight loss and nutritional status on the cognitive performance of patients with anorexia nervosa. The intellectual, memory, attentional, verbal fluency and visuospatial abilities of 34 females with anorexia were compared to that of 31 normal weight-for-height females. Group differences in anxiety and depression were found but neither variable was related to the cognitive performance of patients with anorexia. Moreover, nutritional status and weight loss bore little relationship to the cognitive scores of the patient group. Overall, patients with anorexia were found to be deficient in their ability to recall meaningful prose and visuospatial information. The failure to find many cognitive deficits in this sample may reflect the fact that few patients with anorexia exhibited frank nutritional deficiencies.  相似文献   
927.
Androgens are required for the development and function of the prostate. In a normal human prostate, androgens control the synthesis of proteins such as prostate-specific antigen and human glandular kallikrein. The prostate secretes these proteins as well as a number of other compounds to form the prostatic fluid. Using differential display PCR to detect novel androgen-regulated genes, clathrin heavy chain expression was identified as potentially being up-regulated by androgens in the prostate cancer cell line LNCaP. We report here that the clathrin heavy chain and light chain genes are regulated by androgens. Clathrin heavy chain messenger RNA was up-regulated by androgens in a concentration- and time-specific manner in the LNCaP cell line. Translation of clathrin heavy chain messenger RNA was stimulated by androgens. Steady state levels of clathrin light chains a and b were up-regulated in the presence of androgen in LNCaP cells. Clathrin gene expression was examined in normal rat prostates, and similar results were found. Clathrin heavy chain protein levels in the rat prostate are also affected by the androgen status of the animal. We hypothesize that clathrin may be involved in the exocytosis of androgen-regulated secretory proteins such as prostate-specific antigen and human glandular kallikrein.  相似文献   
928.
Analysis of two human familial cancer syndromes, hereditary nonpolyposis colorectal cancer and familial adenomatous polyposis, indicates that mutations in either one of four DNA mismatch repair gene homologues or the adenomatous polyposis coli (APC) gene, respectively, are important for the development of colorectal cancer. To further investigate the role of DNA mismatch repair in intestinal tumorigenesis, we generated mice with mutations in both Apc and the DNA mismatch repair gene, Pms2. Whereas Pms2-deficient mice do not develop intestinal tumors, mice deficient in Pms2 and heterozygous for Min, an allele of Apc, develop approximately three times the number of small intestinal adenomas and four times the number of colon adenomas relative to Min and Pms2+/-;Min mice. Although Pms2 deficiency clearly increases adenoma formation in the Min background, histological analysis indicated no clear evidence for progression to carcinoma.  相似文献   
929.
Neuronal migration disorders have been involved in various pathologies, including epilepsy, but the properties of the neural networks underlying disorders have not been determined. In the present study, patch clamp recordings were made from intrahippocampal heterotopic as well as from neocortical and hippocampal neurons from brain slices of rats with prenatally methylazoxymethanol-induced cortical malformation. We report that heterotopic neurons have morphometrical parameters and cellular properties of neocortical supragranular neurons and are integrated in both neocortical and hippocampal networks. Thus, stimulation of the white matter induces both antidromic and orthodromic response in heterotopic and neocortical neurons. Stimulation of hippocampal afferents evokes a monosynaptic response in the majority of heterotopic neurons and a polysynaptic all-or-none epileptiform burst in the presence of bicuculline to block gamma-aminobutyric acid type A inhibition. Furthermore, hippocampal paroxysmal activity generated by bath application of bicuculline can spread directly to the neocortex via the heterotopia in methylazoxymethanol-treated but not in naive rats. We conclude that heterotopias form a functional bridge between the limbic system and the neocortex, providing a substrate for pathological conditions.  相似文献   
930.
OBJECTIVE: To examine the effect of treatment with an inactivated, gp120-depleted, HIV-1 immunogen (Remune) in 30 Thai subjects infected with HIV-1 subtype E. DESIGN: Sixty-week open-label study. METHODS: Thirty HIV-positive volunteers with CD4 cell counts > or = 300 x 10(6)/l were given intramuscular injections of Remune into the triceps muscle on day 1 and then at weeks 4, 8, 12, 24, 36, 48 and 60. RESULTS: Treatment with Remune was well-tolerated and augmented HIV-1-specific immune responses. Furthermore, subjects had a significant increase in CD4 cell count (P < 0.0001), CD4 cell percentage (P < 0.0001), CD8 cell percentage (P < 0.0001), and body weight (P < 0.0001) compared with pretreatment levels. Fourteen subjects with detectable viral load at day 1 showed a decrease at week 60 (P=0.04). Retrospective Western blot analysis showed 23 subjects with increased intensity of antibody bands and 15 patients showed development of new reactivities to HIV proteins, especially towards p17 and p15. CONCLUSION: These results indicate that HIV-specific immune-based therapeutic approaches such as Remune should be further examined in countries with different clades of HIV-1 and where access to antiviral drug therapies is limited.  相似文献   
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