DNA is packaged as chromatin in the interphase nucleus. During mitosis, chromatin fibers are highly condensed to form metaphase chromosomes, which ensure equal segregation of replicated chromosomal DNA into the daughter cells. Despite >1 century of research on metaphase chromosomes, information regarding the higher order structure of metaphase chromosomes is limited, and it is still not clear which proteins are involved in further folding of the chromatin fiber into metaphase chromosomes. To obtain a global view of the chromosomal proteins, we performed proteome analyses on three types of isolated human metaphase chromosomes. We first show the results from comparative proteome analyses of two types of isolated human metaphase chromosomes that have been frequently used in biochemical and morphological analyses. 209 proteins were quantitatively identified and classified into six groups on the basis of their known interphase localization. Furthermore, a list of 107 proteins was obtained from the proteome analyses of highly purified metaphase chromosomes, the majority of which are essential for chromosome structure and function. Based on the information obtained on these proteins and on their localizations during mitosis as assessed by immunostaining, we present a four-layer model of metaphase chromosomes. According to this model, the chromosomal proteins have been newly classified into each of four groups: chromosome coating proteins, chromosome peripheral proteins, chromosome structural proteins, and chromosome fibrous proteins. This analysis represents the first compositional view of human metaphase chromosomes and provides a protein framework for future research on this topic.
ABSTRACT-Supplemental doses of antithrombin (AT) are widely used to treat sepsis-induced disseminated intravascular coagulation (DIC) in Japan. However, evidence on the benefits of ATsupplementation for DIC is insufficient. This multicenter retrospective observational study aimed to clarify the effect of AT supplementation on sepsis-induced DIC using propensity score analyses. Data from 3,195 consecutive adult patients admitted to 42 intensive care units for severe sepsis treatment were retrospectively analyzed; 1,784 patients were diagnosed with DIC (n ¼ 715, AT group; n ¼ 1,069, control group). Inverse probability of treatment-weighted propensity score analysis indicated a statistically significant association between AT supplementation and lower in-hospital all-cause mortality (n ¼ 1,784, odds ratio [95% confidence intervals]: 0.748 [0.572-0.978], P ¼ 0.034). However, quintile-stratified propensity score analysis (n ¼ 1,784, odds ratio: 0.823 [0.646-1.050], P ¼ 0.117) and propensity score matching analysis (461 matching pairs, odds ratio: 0.855 [0.649-1.125], P ¼ 0.263) did not show this association. In the early days after intensive care unit admission, the survival rate was statistically higher in the propensity score-matched AT group than in the propensity score-matched control group (P ¼ 0.007). In DIC patients without concomitant heparin administration, similar results were observed. In conclusion, AT supplementation may be associated with reduced in-hospital all-cause mortality in patients with sepsis-induced DIC. However, the statistical robustness of this connection was not strong. In addition, although the number of transfusions needed in patients with AT supplementation increased, severe bleeding complications did not.
Severe sepsis is a major concern in the intensive care unit (ICU), although there is very little epidemiological information regarding severe sepsis in Japan. This study evaluated 3195 patients with severe sepsis in 42 ICUs throughout Japan. The patients with severe sepsis had a mean age of 70 ± 15 years and a mean Acute Physiology and Chronic Health Evaluation II score of 23 ± 9. The estimated survival rates at 28 and 90 days after ICU admission were 73.6 and 56.3 %, respectively.Electronic supplementary materialThe online version of this article (doi:10.1186/s40560-016-0169-9) contains supplementary material, which is available to authorized users.
The human cell cycle was synchronized and the chromosomes were isolated by a centrifugation method using two representative solutions for chromosome isolation (a polyamine buffer, PAB and citric acid solution, CAS) and fixatives. The centrifugation method yielded sufficient amounts of human metaphase chromosomes. Observation of the isolated chromosomes by scanning electron microscopy (SEM) revealed two types of surface structure which have been repeatedly reported to date: the human chromosomes in the PAB were relatively smooth but covered irregularly with scaly structures, while the surface of the chromosomes in the CAS exhibited a dense fibrous structure with a uniform diameter of 50-70 nm. Comparison of proteins extracted from chromosomes isolated with the PAB and CAS clearly indicated the removal of linker histones, H1, from chromosomes isolated with the CAS. These findings imply that the two different images of human chromosomes frequently observed by SEM are due to the removal of peripheral chromosomal materials including linker histones and/or the depletion of linker histones which prevent the surface chromatin fibers from scattering.
In higher eukaryotic cells, DNA molecules are present as chromatin fibers, complexes of DNA with various types of proteins; chromatin fibers are highly condensed in metaphase chromosomes during mitosis. Although the formation of the metaphase chromosome structure is essential for the equal segregation of replicated chromosomal DNA into the daughter cells, the mechanism involved in the organization of metaphase chromosomes is poorly understood. To identify proteins involved in the formation and/or maintenance of metaphase chromosomes, we examined proteins that dissociated from isolated human metaphase chromosomes by 0.4 M NaCl treatment; this treatment led to significant chromosome decondensation, but the structure retained the core histones. One of the proteins identified, HP1-BP74 (heterochromatin protein 1-binding protein 74), composed of 553 amino acid residues, was further characterized. HP1-BP74 middle region (BP74Md), composed of 178 amino acid residues (Lys 97 -Lys 274 ), formed a chromatosome-like structure with reconstituted mononucleosomes and protected the linker DNA from micrococcal nuclease digestion by ϳ25 bp. The solution structure determined by NMR revealed that the globular domain (Met 153 -Thr 237 ) located within BP74Md possesses a structure similar to that of the globular domain of linker histones, which underlies its nucleosome binding properties. Moreover, we confirmed that BP74Md and fulllength HP1-BP74 directly binds to HP1 (heterochromatin protein 1) and identified the exact sites responsible for this interaction. Thus, we discovered that HP1-BP74 directly binds to HP1, and its middle region associates with linker DNA at the entry/exit site of nucleosomal DNA in vitro.
BackgroundAn emergency department encounters a variety of cases, including rare cases of the strangulation of a mesenteric lipoma by the greater omentum band.Case presentationA 67-year-old Japanese man presented with nausea, vomiting, and upper abdominal pain. There were no abnormalities detected by routine blood tests other than a slight rise in his white cell count. A contrast-enhanced computed tomography scan of his abdomen revealed a dilated intestine, a small intestine volvulus, and a well-capsulated homogeneous mass. He was suspected of having a small intestine volvulus that was affected by a mesenteric lipoma; therefore, single-port laparoscopic surgery was performed. Laparoscopy revealed a small intestine volvulus secondary to the strangulation of a mesenteric lipoma. The band and tumor were removed. He had no postoperative complications and was discharged on postoperative day 6.ConclusionsAlthough this case was an emergency, it showed that single-port laparoscopic surgery can be a safe, useful, and efficacious procedure.
BackgroundThe administration of low-dose intravenous immunoglobulin G (IVIgG) (5 g/day for 3 days; approximate total 0.3 g/kg) is widely used as an adjunctive treatment for patients with sepsis in Japan, but its efficacy in the reduction of mortality has not been evaluated. We investigated whether the administration of low-dose IVIgG is associated with clinically important outcomes including intensive care unit (ICU) and in-hospital mortality.MethodsThis is a post-hoc subgroup analysis of data from a retrospective cohort study, the Japan Septic Disseminated Intravascular Coagulation (JSEPTIC DIC) study. The JSEPTIC DIC study was conducted in 42 ICUs in 40 institutions throughout Japan, and it investigated associations between sepsis-related coagulopathy, anticoagulation therapies, and clinical outcomes of 3195 adult patients with sepsis and septic shock admitted to ICUs from January 2011 through December 2013. To investigate associations between low-dose IVIgG administration and mortalities, propensity score-based matching analysis was used.ResultsIVIgG was administered to 960 patients (30.8%). Patients who received IVIgG were more severely ill than those who did not (Acute Physiology and Chronic Health Evaluation (APACHE) II score 24.2 ± 8.8 vs 22.6 ± 8.7, p < 0.001). They had higher ICU mortality (22.8% vs 17.4%, p < 0.001), but similar in-hospital mortality (34.4% vs 31.0%, p = 0.066). In propensity score-matched analysis, 653 pairs were created. Both ICU mortality and in-hospital mortality were similar between the two groups (21.0% vs 18.1%, p = 0.185, and 32.9% vs 28.6%, p = 0.093, respectively) using generalized estimating equations fitted with logistic regression models adjusted for other therapeutic interventions. The administration of IVIgG was not associated with ICU or in-hospital mortality (odds ratio (OR) 0.883; 95% confidence interval (CI) 0.655–1.192, p = 0.417, and OR 0.957, 95% CI, 0.724–1.265, p = 0.758, respectively).ConclusionsIn this analysis of a large cohort of patients with sepsis and septic shock, the administration of low-dose IVIgG as an adjunctive therapy was not associated with a decrease in ICU or in-hospital mortality.Trial registrationUniversity Hospital Medical Information Network Individual Clinical Trials Registry, UMIN-CTR000012543. Registered on 10 December 2013.Electronic supplementary materialThe online version of this article (doi:10.1186/s13054-017-1764-4) contains supplementary material, which is available to authorized users.
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