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661.
We describe a transgenic mouse line carrying the cre transgene under the control of the adenovirus EIIa promoter that targets expression of the Cre recombinase to the early mouse embryo. To assess the ability of this recombinase to excise loxP-flanked DNA sequences at early stages of development, we bred EIIa-cre transgenic mice to two different mouse lines carrying loxP-flanked target sequences: (i) a strain with a single gene-targeted neomycin resistance gene flanked by 1oxP sites and (ii) a transgenic line carrying multiple transgene copies with internal loxP sites. Mating either of these loxP-carrying mouse lines to EIIa-cre mice resulted in first generation progeny in which the loxP-flanked sequences had been efficiently deleted from all tissues tested, including the germ cells. Interbreeding of these first generation progeny resulted in efficient germ-line transmission of the deletion to subsequent generations. These results demonstrate a method by which loxP-flanked DNA sequences can be efficiently deleted in the early mouse embryo. Potential applications of this approach are discussed, including reduction of multicopy transgene loci to produce single-copy transgenic lines and introduction of a variety of subtle mutations into the line.  相似文献   
662.
OBJECTIVE: To assess the role of circulating adhesion molecules and chemotactic cytokines within different settings of major trauma. DESIGN: Retrospective study. SETTING: Teaching hospitals, USA and Germany. SUBJECTS: Two groups of patients with multiple injuries (group I n = 155 and group II n = 12) with mean (SEM) injury severity scores (ISS) of 35 (4) and 32 (4) points, respectively, and 18 burned patients with a mean of ISS 38 (9) points. INTERVENTIONS: Serum samples were collected at the site of the accident and on admission to the (Group I) as well as during the post-trauma course in the hospital (Group II: days 1, 3, 5, 7, 10; Group III; weekly, up to week 10). MAIN OUTCOME MEASURES: Measurement of concentrations of soluble (s) adhesion molecules (sE-selectin, sP-selectin), and chemotactic cytokines (interleukin-8 [IL-8], epithelial cell derived neutrophil activating peptide 78 [ENA-78]) in serum after major mechanical trauma and burns. RESULTS: High concentrations of ENA-78 and sP-selectin were already present at the site of accident as well as one hour after injury. During recovery from the injuries, persistently high concentrations of IL-8, ENA-78, and sP-selectin were found, but sE-selectin was increased only during the first week after major trauma. CONCLUSION: Massive tissue trauma causes immediate activation of selected chemokines and adhesion molecules within minutes of the injury which will then persist depending on the type and severity of the injury for a substantial length of time. There was, however, no correlation between serum concentrations of the mediators investigated and susceptibility to complications or outcome.  相似文献   
663.
The androgen receptor (AR) was measured by an immunoblot assay in adult tissues of both male and female rats. Relatively high levels of AR were detected in tissues of the male urogenital tract and in the adrenal glands and gonads of both sexes. Another group of tissues, including the male levator ani/bulbocavernosus muscles, preputial gland, scrotal skin, and vagina, had low, but detectable, levels of AR. In a third group of tissues, including the uterus, kidney, spleen, liver, gut, heart, lung, pituitary, and hypothalamus, AR was undetectable. In some androgen target tissues, such as the penis, androgens cause an apparent disappearance of AR from the tissue, and in other tissues, such as the ventral prostate, androgen therapy increases the amount of detectable AR. We compared the effect of androgen on AR levels in the adrenal gland and ventral prostate, tissues that differ markedly in their trophic responses to androgen. Castration appeared to have no effect on the amount of detectable AR in the adrenal gland, whereas it caused a profound decrease in AR levels in the ventral prostate. By contrast, 7 days after hypophysectomy, AR levels declined in both the adrenal gland and the ventral prostate. The effects of hypophysectomy plus castration were similar to those of hypophysectomy alone. Administration of ACTH to hypophysectomized rats for 7 days did not reverse the effects of hypophysectomy on adrenal AR, nor did treatment with levothyroxine, dexamethasone, rat GH, or rat PRL. Treatment of hypophysectomized rats with 5alpha-dihydrotestosterone for 7 days caused a dramatic increase in the amount of detectable AR in both the ventral prostate and the adrenal gland, but had a trophic effect only in the ventral prostate. These findings suggest that the amount of immunoreactive AR detected in both the adrenal gland and the ventral prostate is enhanced by androgens: testicular androgens in the case of the ventral prostate and adrenal androgen in the case of the adrenal glands.  相似文献   
664.
A phylogenetic analysis was performed on two previously uncharacterized Gram-positive, catalase-negative bacteria from clinical sources. 16S rRNA sequencing studies revealed the isolates represent a new line of descent within the lactic acid group of bacteria. On the basis of the phylogenetic findings and phenotypic distinctiveness of the organisms, it is proposed that they be classified in a new genus Dolosigranulum, as Dolosigranulum pigrum sp. nov. The type strain of Dolosigranulum pigrum is NCFB 2975.  相似文献   
665.
OBJECTIVE: To determine the significance of an atypical squamous cells of undetermined significance (ASCUS) diagnosis in patients 18 years or younger. STUDY DESIGN: From June 1994 to June 1995, 630 cervicovaginal smears were performed on patients 18 years or younger (mean age 16.4, range 14-18) at University Hospitals of Cleveland. Of these patients, 69 (10.9%) were diagnosed with ASCUS or ASCUS with a qualifying statement. Follow-up cervicovaginal smears, biopsies and charts were reviewed for a 12-18-month period following the initial diagnosis of ASCUS. RESULTS: The study population was sexually active: 63% were gravid, 21% were multigravid, 68% had a history of sexually transmitted diseases (STDs), and 32% had multiple STDs. Follow-up cervicovaginal smears or biopsies were obtained on 46 patients (32 cervicovaginal smears and 14 biopsies/endocervical curettage cases). Mild to moderate dysplasia was identified in 21.6% of patients (10.8% on cervicovaginal smears and 10.8% on biopsies), and a repeat diagnosis of ASCUS was given in 37%. In patients with a repeat diagnosis of ASCUS, a follow-up cervicovaginal smear or biopsy revealed dysplasia in an additional 13%. The overall rate of dysplasia was 34.7%. CONCLUSION: Regardless of age, the diagnosis of ASCUS in a sexually active patient population has significant implications. Furthermore, we recommend that these patients be managed the same way as high-risk adult patients.  相似文献   
666.
CheY is a signal transduction protein of the bacterial chemotaxis system that acts as a molecular switch to alter the swimming behavior of the bacterium. When CheY becomes phosphorylated at Asp57, CheY-Pi interacts with flagellar motor proteins, including FliM, to increase the likelihood that the flagellar motor will change its sense of rotation, increasing the frequency of tumbling. The structure of CheY in its dephosphorylated (inactive) state has been intensively investigated. The short lifetime ( approximately 20 s) of the aspartyl phosphate has precluded the complete structural determination of CheY-Pi. We have synthesized an analogue of CheY-Pi by alkylating an aspartate-to-cysteine mutant at position 57 of CheY to add a phosphonomethyl group at Cys57. This analogue, phosphono-CheY, is stable for months. Phosphono-CheY binds to two of the targets of CheY-Pi, FliM and CheZ, in a manner similar to that of CheY-Pi and much better than either unphosphorylated CheY or the unmodified form of D57C CheY. Phosphono-CheY also binds Mg(II) with a dissociation constant of approximately 6 mM at neutral pH and moderate salt level. These observations indicate that phosphono-CheY is a good biochemical analogue of CheY-Pi.  相似文献   
667.
668.
A long-term electrophoretic survey on plasma proteins, which was carried out in several clinical laboratories in Italy, identified 28 different genetic variants of human serum albumin and four cases of analbuminemia. We have previously characterized 16 point mutations, 3 C-terminal mutants, and the genetic defects in two analbuminemic subjects. Here, we report the molecular defects of four alloalbumins that have been characterized by protein structural analysis. Of these, three represent new single-point mutations: albumins Tregasio, Val122-->Glu, Bergamo, Asp314-->Gly, and Maddaloni, Val533-->Met. The fourth, albumin Besana Brianza, has the same Asp494-->Asn mutation that introduces a glycosylation site which has been previously reported in a variant from New Zealand, albumin Casebrook. However, in contrast to albumin Casebrook, albumin Besana Brianza is only partially glycosylated and the oligosaccharide is heterogeneous, consisting of a biantennary complex type N-glycan with either two or one sialic acid residue(s) on the antennae. Both albumin Maddaloni and Besana Brianza represent mutations at hypermutable CpG dinucleotide sites; albumin Maddaloni is a mutant that does not involve a charged amino acid.  相似文献   
669.
A significant percentage of elderly women has been found to have ulnar deviation. As measured at the middle finger, the mean deviation of 73 degrees is small, but nearly 25% of subjects showed a clinically visible deviation of between 11 degrees and 25 degrees. Ulnar deviation has been noted in subjects who are not suffering from the diseases and states commonly regarded as being important to its aetiology. In those it may represent the end-point of the progressive drift considered by some to be a normal ageing process. Whether the aetiology lies here or in one of the other diseases of the locomotor or central nervous systems is uncertain, but caution should be used when interpreting the clinical sign in the elderly.  相似文献   
670.
A rapid, simplified method of checking the calibration of a new motorized pendulum type of tablet hardness tester and the accuracy and precision of three testers were determined. Two force gauges were calibrated, and both gauges were used by two operators to determine the accuracy of the new testers. The calibration method using the force gauge was reliable for checking the accuracy. The results show the various new testers to be in calibration and to give reproducible results.  相似文献   
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