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1.
Two cases of squamous cell carcinoma of the prepuce arising on balanitis xerotica obliterans are described. This event is unusual and not well known. The surgical treatment was a wide circumcision in which the prepuce and part of the shaft skin were removed, performing as well a decortication of the glans base. This technique seemed to be satisfactory in removing the carcinoma and obtaining a definite improvement in the clinical picture of balanitis xerotica obliterans as well.  相似文献   
2.
The structure of the hernoglobin α-chain of Rose-ringed Parakeet was determined by sequence degradations of the intact subunit, the CNBr fragments, and peptides obtained by digestion with staphylococcal Glu-specific protease and trypsin. Using this analysis, the complete α-chain structure of 21 avian species is known, permitting comparisons of the protein structure and of avian relationships. The structure exhibits differences from previously established avian α-chains at a total of 61 positions, five of which have residues unique to those of the parakeet (Ser-12, Gly-65, Ser-67, Ala-121, and Leu-134). The analysis defines hemoglobin variation within an additional avian order (Psittaciformes), demonstrates distant patterns for evaluation of relationships within other avian orders, and lends support to taxonomic conclusions from molecular data.  相似文献   
3.
A survey of the occurrence of strains of Erwinia amylovora resistant to streptomycin in certain Egyptian pear orchards was earned out during April and May 1988. Twenty-two isolates out of 604 isolates collected from 11 orchards showed resistance to streptomycin. All the streptomycin resistant (Strr) strains isolated in the present work were resistant to high levels of streptomycin with minimal inhibitory concentrations ranging from 1000 to 3000 μg/ml. The occurrence of Strr strains in Egypt is still limited and the population of resistant strains was at relatively low level. However, such occurrence of E. amylovora with resistance to streptomycin is a potentially serious situation.  相似文献   
4.
Iron deprivation of Erwinia amylovora CFBP1430, a species causing fire blight on Pomoïdeae, was shown to induce the production of siderophores of the desferrioxamine (dfo) family and two outer membrane polypeptides with apparent molecular weight of about 70 and 80 kDa, respectively. Cyclic dfo E was characterized as the major metabolite. Phage MudIIpR13 insertional mutagenesis and screening on CAS-agar medium yielded three dfo non-producing and one overproducing clones. These clones failed to grow in the presence of the Fe(III) chelator EDDHA and were determined further as dfo and ferrioxamine transport negative mutants, respectively. The transport mutant which appeared to lack the 70 kDa polypeptide in the outer membrane allowed the purification of dfo E. Growth under iron limitation of dfo negative mutants was stimulated with ferrioxamine E and B but not with other ferrisiderophores tested. The host DNA sequence flanking the left terminal part of the MudIIpR13 prophage responsible for the transport mutation was cloned and used to probe a parental gene library by DNA-DNA hybridization. Two recombinant cosmids restoring the transport mutation to normal were identified. Both cosmids also conferred the ability to utilize ferrioxamine B and E as iron sources on a FhuE1 mutant of Escherichia coli. This correlated with the production of an additional polypeptide of 70 kDa in the outer membrane of E. coli transconjugants, thus confirming that this protein serves the ferrioxamine receptor function (FoxR) in E. amylovora.R. Kachadourian and A. Dellagi have contributed equally to this work.  相似文献   
5.
Glycinebetaine is one of the compatible solutes that accumulate in the chloroplasts of certain halotolerant plants when these plants are exposed to salt or cold stress. The codA gene for choline oxidase, the enzyme that converts choline into glycinebetaine, has previously been cloned from a soil bacterium, Arthrobacter globiformis. Transformation of Arabidopsis thaliana with the cloned codA gene under the control of the 35S promoter of cauliflower mosaic virus enabled the plant to accumulate glycinebetaine and enhanced its tolerance to salt and cold stress. At 300 mM NaCl, considerable proportions of seeds of transformed plants germinated well, whereas seeds of wild-type plants failed to germinate. At 100 mM NaCl, transformed plants grew well whereas wild-type plants did not do so. The transformed plants tolerated 200 mM NaCl, which was lethal to wild-type plants. After plants had been incubated with 400 mM NaCl for two days, the photosystem II activity of wild-type plants had almost completely disappeared, whereas that of transformed plants remained at more than 50% of the original level. When exposed to a low temperature in the light, leaves of wild-type plants exhibited symptoms of chlorosis, whereas those of transformed plants did not. These observations demonstrate that the genetic modification of Arabidopsis thaliana that allowed it to accumulate glycinebetaine enhanced its ability to tolerate salt and cold stress.  相似文献   
6.
Summary Recombinational repair is the means by which DNA double-strand breaks (DSBs) are repaired in yeast. DNA divergence between chromosomes was shown previously to inhibit repair in diploid G1 cells, resulting in chromosome loss at low nonlethal doses of ionizing radiation. Furthermore, 15–20% divergence prevents meiotic recombination between individual pairs of Saccharomyces cerevisiae and S. carlsbergensis chromosomes in an otherwise S. cerevisiae background. Based on analysis of the efficiency of DSB-induced chromosome loss and direct genetic detection of intragenic recombination, we conclude that limited DSB recombinational repair can occur between homoeologous chromosomes. There is no difference in loss between a repair-proficient Pms+ strain and a mismatch repair mutant, pms1. Since DSB recombinational repair is tolerant of diverged DNAs, this type of repair could lead to novel genes and altered chromosomes. The sensitivity to DSB-induced loss of 11 individual yeast artificial chromosomes (YACs) containing mouse or human (chromosome 21 or HeLa) DNA was determined. Recombinational repair between a pair of homologous HeLa YACs appears as efficient as that between homologous yeast chromosomes in that there is no loss at low radiation doses. Single YACs exhibited considerable variation in response, although the response for individual YACs was highly reproducible. Based on the results with the yeast homoeologous chromosomes, we propose that the potential exists for intra- YAC recombinational repair between diverged repeat DNA and that the extent of repair is dependent upon the amount of repeat DNA and the degree of divergence. The sensitivity of YACs containing mammalian DNA to ionizing radiation-induced loss may thus be an indicator of the extent of repeat DNA.  相似文献   
7.
Proliferating cell nuclear antigen is required for DNA excision repair.   总被引:95,自引:0,他引:95  
K K Shivji  M K Kenny  R D Wood 《Cell》1992,69(2):367-374
Fractionation of extracts from human cell lines allows nucleotide excision repair of damaged DNA to be resolved into discrete incision and polymerization stages. Generation of incised intermediates depends on the XP-A protein, a polypeptide that recognizes sites of damaged DNA, and on the human single-stranded DNA-binding protein HSSB. The proliferating cell nuclear antigen (PCNA) is required for the DNA synthesis that converts the nicked intermediates to completed repair events. This need for PCNA implies that repair synthesis is carried out by DNA polymerase delta or epsilon. The ability to visualize repair intermediates in the absence of PCNA facilitates dissection of the multiprotein reaction that leads to incision of damaged DNA in a major pathway of cellular defense against mutagens.  相似文献   
8.
This work investigated the polar (PC: protein, amino acid and metabolite) and non‐polar (NPC: fatty acid) compounds and bioactivity characteristics of the EBN harvested from the state of Johor in Malaysia. The electrophoretic gels exhibited 15 protein bands (16–173 kD) with unique protein profile. Amino acids analysis by AccQ?Tag method revealed 18 types of amino acids in EBN. Metabolite profiling was performed using High‐Performance Liquid Chromatography coupled with Quadrupole Time‐of‐Flight Mass Spectrometer (HPLC‐QTOF/MS) technique and a total of 54 compounds belonging to different groups were detected and identified. These findings help to uncover the relation of therapeutic activity of EBN. The EBN was further extracted with AcOEt and BuOH. The AcOEt extract was fractionated into three fractions (F1?F3), and the high triglyceride content in F2 was verified by gC‐FID. The three groups of fatty acids discovered in EBN are 48.43 % of poly‐unsaturated (PUFA), 25.35 % of saturated fatty acids (SFA) and 24.74 % of mono‐unsaturated fat (MUFA). This is the first time to report results ofEBN, BuOH, and AcOEt extracts and of fraction F2 (TEBN) on their analysis for their antioxidant activities by DPPH, ABTS and catalase assay and for their paraoxonase and anti‐tyrosinase activities. The results showed that TEBN exhibited the significant bioactivity in all assays. These findings suggest that TEBN is a good source for natural bioactive compounds in promoting body vigor. Current work widened the content of EBN especially on the triglyceride and also marked the content of specific location (Johor, Malaysia) of EBN origin.  相似文献   
9.

Background

The Centers for Disease Control and Prevention recommends nontargeted opt-out HIV screening in healthcare settings. Cost effectiveness is critical when considering potential screening methods. Our goal was to compare programmatic costs of nontargeted opt-out rapid HIV screening with physician-directed diagnostic rapid HIV testing in an urban emergency department (ED) as part of the Denver ED HIV Opt-Out Trial.

Methods

This was a prospective cohort study nested in a larger quasi-experiment. Over 16 months, nontargeted rapid HIV screening (intervention) and diagnostic rapid HIV testing (control) were alternated in 4-month time blocks. During the intervention phase, patients were offered HIV testing using an opt-out approach during registration; during the control phase, physicians used a diagnostic approach to offer HIV testing to patients. Each method was fully integrated into ED operations. Direct program costs were determined using the perspective of the ED. Time-motion methodology was used to estimate personnel activity costs. Costs per patient newly-diagnosed with HIV infection by intervention phase, and incremental cost effectiveness ratios were calculated.

Results

During the intervention phase, 28,043 eligible patients were included, 6,933 (25%) completed testing, and 15 (0.2%, 95% CI: 0.1%–0.4%) were newly-diagnosed with HIV infection. During the control phase, 29,925 eligible patients were included, 243 (0.8%) completed testing, and 4 (1.7%, 95% CI: 0.4%–4.2%) were newly-diagnosed with HIV infection. Total annualized costs for nontargeted screening were $148,997, whereas total annualized costs for diagnostic HIV testing were $31,355. The average costs per HIV diagnosis were $9,932 and $7,839, respectively. Nontargeted HIV screening identified 11 more HIV infections at an incremental cost of $10,693 per additional infection.

Conclusions

Compared to diagnostic testing, nontargeted HIV screening was more costly but identified more HIV infections. More effective and less costly testing strategies may be required to improve the identification of patients with undiagnosed HIV infection in the ED.  相似文献   
10.
The solid-state photo-CIDNP (photochemically induced dynamic nuclear polarization) effect is studied in photosynthetic reaction centers of Heliobacillus mobilis at different magnetic fields by 13C MAS (magic-angle spinning) NMR spectroscopy. Two active states of heliobacterial reaction centers are probed: an anaerobic preparation of heliochromatophores (“Braunstoff”, German for “brown substance”) as well as a preparation of cells after exposure to oxygen (“Grünstoff”, “green substance”). Braunstoff shows significant increase of enhanced absorptive (positive) signals toward lower magnetic fields, which is interpreted in terms of an enhanced differential relaxation (DR) mechanism. In Grünstoff, the signals remain emissive (negative) at two fields, confirming that the influence of the DR mechanism is comparably low.  相似文献   
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