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The centromere-kinetochore complexes of Chinese hamster ovary (CHO) cells were detached and separated from the condensed chromatin by treatment with hydroxyurea and caffeine. By labelling the complex for immunoelectron microscopy (immuno-EM) with a mixture of antibodies against centromere proteins (anti-CENP-A,-B, -C) in some cells, we could demonstrate complete detachment of the complexes. No remnants were left at the bulk of condensed chromatin in these cells. In some mitotic cells complex and chromatin were found side by side. It could be shown that the fine structure of the separated material of the complex differs significantly from that of the rest of chromatin. The complex consists of proteins and DNA. This leads us to suppose that the organization of chromatin in the centromere-kinetochore complex is different.  相似文献   
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Gastroesophageal reflux disease (GERD) is the most common disease of the upper gastrointestinal tract. With the introduction of proton pump inhibitors medical treatment of GERD has been significantly improved. However, the development of laparoscopic antireflux surgery resulted in an increasing interest of surgeons in this disease. An interactive meeting was organized in order to develop an agreement between gastoenterologists and surgeons regarding therapeutic decisions and this is the main topic of this paper.  相似文献   
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STUDY OBJECTIVE: The study was performed to evaluate the relative sensitivity of various noninvasive methods to detect and describe the systolic cardiovascular effects of stepwise increasing doses of isoproterenol: two-dimensional left ventricular echocardiography (main variable, ejection fraction), ACVF (attenuation compensated volume flow)--dual-beam Doppler echoaortography (time-averaged mean velocity), electrical impedance cardiography [(dZ/dtmax)/RZ index], and systolic time intervals from mechanocardiography (PEP and QS2c). METHODS: Isoproterenol was administered by constant rate intravenous infusion in consecutive steps of 0.1, 0.2, 0.4, 0.75, and 1.5 micrograms/min (each for 15 minutes). Saline control infusions were given in analog fashion. The treatments (isoproterenol and saline solution) were administered in a period-balanced two-way crossover design with randomly allocated sequences. The subjects, observers, and analysts were blinded to the treatment protocol. Study subjects were 10 healthy male volunteers (age range, 23 to 31 years; mean age, 26.6 years). RESULTS: Compared with saline solution, isoproterenol caused a dose-related increase in ejection fraction, (dz/dt)/RZ index, and time-averaged mean velocity and a dose-related shortening of PEP and QS2c. The responses are congruent with an enhancement of cardiac systolic performance caused by a positive inotropic stimulation and an afterload reduction ("inodilatory" response). The effects on systolic time intervals reached statistical significance (alpha = 0.05) at the first isoproterenol dose step, the effects on the impedance cardiography and the Doppler echoaortography variables reached statistical significance at the second dose step, and the effects on the two-dimensional echocardiography reached statistical significance at the third dose step. CONCLUSIONS: All methods allowed to detect isoproterenol-related changes. Systolic time intervals were the most sensitive, followed by impedance cardiography, ACVF--dual-beam Doppler echoaortography, and two-dimensional echocardiography. The practical convenience and high sensitivity of the systolic time intervals makes them suitable to evaluate investigational systolic inodilatory changes in humans.  相似文献   
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Human beta-defensin 2 (DEFB4, also known as DEFB2 or hBD-2) is a salt-sensitive antimicrobial protein that is expressed in lung epithelia. Previous work has shown that it is encoded in a cluster of beta-defensin genes at 8p23.1, which varies in copy number between 2 and 12 in different individuals. We determined the copy number of this locus in 355 patients with cystic fibrosis (CF), and tested for correlation between beta-defensin cluster genomic copy number and lung disease associated with CF. No significant association was found.  相似文献   
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Thanatophoric dwarfism (TD) is a sporadic lethal skeletal dysplasia with micromelic shortening of the limbs, macrocephaly, platyspondyly and reduced thoracic cavity. In the most common subtype (TD1), femurs are curved, while in TD2, straight femurs are associated with cloverleaf skull. Mutations in the fibroblast growth factor receptor 3 (FGFR3) gene were identified in both subtypes. While TD2 was accounted for by a single recurrent mutation in the tyrosine kinase 2 domain, TD1 resulted from either stop codon mutations or missense mutations in the extracellular domain of the gene. Here, we report the identification of FGFR3 mutations in 25/26 TD cases. Two novel missense mutations (Y373C and G370C) were detected in 8/26 and 1/26 TD1 cases respectively. Both mutations created cysteine residues in the juxta extramembrane domain of the receptor. Sixteen cases carried the previously reported R248C (9/26 cases), S249C (2/26 cases) or stop codon FGFR3 mutations (5/26 cases). Our results suggest that TD1 is a genetically homogeneous condition and give additional support to the view that newly created cysteine residues in the extracellular domain of the protein play a key role in the severity of the disease.   相似文献   
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