Adverse Events during Bowel Preparation and Colonoscopy in Patients with Acute Lower Gastrointestinal Bleeding Compared with Elective Non-Gastrointestinal Bleeding

Background

There are limited data on the safety of colonoscopy in patients with lower gastrointestinal bleeding (LGIB). We examined the various adverse events associated with colonoscopy in acute LGIB compared with non-GIB patients.

Methods

Emergency hospitalized LGIB patients (n = 161) and age- and gender-matched non-GIB controls (n = 161) were selected. Primary outcomes were any adverse events during preparation and colonoscopy procedure. Secondary outcomes were five bowel preparation-related adverse events–hypotension, systolic blood pressure <100 mmHg, volume overload, vomiting, aspiration pneumonia and loss of consciousness–and four colonoscopy-related adverse events–including hypotension, perforation, cerebrocardiovascular events and sepsis.

Results

During bowel preparation, 16 (9%) LGIB patients experienced an adverse event. None of the LGIB patients experienced volume overload, aspiration pneumonia or loss of consciousness; however, 12 (7%) had hypotension and 4 (2%) vomited. There were no significant differences in the five bowel preparation-related adverse events between LGIB and non-GIB patients. During colonoscopy, 25 (15%) LGIB patients experienced an adverse event. None LGIB patient had perforation or sepsis; however, 23 (14%) had hypotension and 2 (1%) experienced a cerebrocardiovascular event. There was no significant difference in the four colonoscopy-related adverse events between LGIB and non-GIB patients. In addition, no significant difference in any of the nine adverse events was found among subgroups: patients aged ≥65 years, those with comorbidities, and those with antithrombotic drug use.

Conclusions

Adverse events in bowel preparation and colonoscopy among acute LGIB patients were low. No significant difference was found in adverse events between LGIB and non-GIB patients. These adverse events were also low in elderly LGIB patients, as well as in those with co-morbidities and antithrombotic drug use, suggesting that colonoscopy performed during acute LGIB did not increase adverse events.     

Ultra-High-Throughput Screening of an In Vitro-Synthesized Horseradish Peroxidase Displayed on Microbeads Using Cell Sorter

The C1a isoenzyme of horseradish peroxidase (HRP) is an industrially important heme-containing enzyme that utilizes hydrogen peroxide to oxidize a wide variety of inorganic and organic compounds for practical applications, including synthesis of fine chemicals, medical diagnostics, and bioremediation. To develop a ultra-high-throughput screening system for HRP, we successfully produced active HRP in an Escherichia coli cell-free protein synthesis system, by adding disulfide bond isomerase DsbC and optimizing the concentrations of hemin and calcium ions and the temperature. The biosynthesized HRP was fused with a single-chain Cro (scCro) DNA-binding tag at its N-terminal and C-terminal sites. The addition of the scCro-tag at both ends increased the solubility of the protein. Next, HRP and its fusion proteins were successfully synthesized in a water droplet emulsion by using hexadecane as the oil phase and SunSoft No. 818SK as the surfactant. HRP fusion proteins were displayed on microbeads attached with double-stranded DNA (containing the scCro binding sequence) via scCro-DNA interactions. The activities of the immobilized HRP fusion proteins were detected with a tyramide-based fluorogenic assay using flow cytometry. Moreover, a model microbead library containing wild type hrp (WT) and inactive mutant (MUT) genes was screened using fluorescence-activated cell-sorting, thus efficiently enriching the WT gene from the 1:100 (WT:MUT) library. The technique described here could serve as a novel platform for the ultra-high-throughput discovery of more useful HRP mutants and other heme-containing peroxidases.     

Clarification of the Identity of the Tea Green Leafhopper Based on Morphological Comparison between Chinese and Japanese Specimens

Tea green leafhopper is one of the most dominant pests in major tea production regions of East Asia. This species has been variously identified as Empoasca vitis (Goëthe), Jacobiasca formosana (Paoli) and Empoasca onukii Matsuda in Mainland China, Taiwan and Japan, respectively. Recent study of DNA sequence data suggested that treatment of this pest as different species in these three adjacent regions is incorrect and that they were a single species; but the correct scientific name for the species has remained unclear. Consistent with the prior molecular evidence, morphological study shows that the male genital characters of Chinese specimens are the same as those of specimens from Japan, so the correct scientific name of tea green leafhopper in China is Empoasca (Matsumurasca) onukii Matsuda.     

Optimal Ancient DNA Yields from the Inner Ear Part of the Human Petrous Bone

The invention and development of next or second generation sequencing methods has resulted in a dramatic transformation of ancient DNA research and allowed shotgun sequencing of entire genomes from fossil specimens. However, although there are exceptions, most fossil specimens contain only low (~ 1% or less) percentages of endogenous DNA. The only skeletal element for which a systematically higher endogenous DNA content compared to other skeletal elements has been shown is the petrous part of the temporal bone. In this study we investigate whether (a) different parts of the petrous bone of archaeological human specimens give different percentages of endogenous DNA yields, (b) there are significant differences in average DNA read lengths, damage patterns and total DNA concentration, and (c) it is possible to obtain endogenous ancient DNA from petrous bones from hot environments. We carried out intra-petrous comparisons for ten petrous bones from specimens from Holocene archaeological contexts across Eurasia dated between 10,000-1,800 calibrated years before present (cal. BP). We obtained shotgun DNA sequences from three distinct areas within the petrous: a spongy part of trabecular bone (part A), the dense part of cortical bone encircling the osseous inner ear, or otic capsule (part B), and the dense part within the otic capsule (part C). Our results confirm that dense bone parts of the petrous bone can provide high endogenous aDNA yields and indicate that endogenous DNA fractions for part C can exceed those obtained for part B by up to 65-fold and those from part A by up to 177-fold, while total endogenous DNA concentrations are up to 126-fold and 109-fold higher for these comparisons. Our results also show that while endogenous yields from part C were lower than 1% for samples from hot (both arid and humid) parts, the DNA damage patterns indicate that at least some of the reads originate from ancient DNA molecules, potentially enabling ancient DNA analyses of samples from hot regions that are otherwise not amenable to ancient DNA analyses.     

Isolation and characterization of a novel bacterium, <Emphasis Type="Italic">Sphingomonas bisphenolicum</Emphasis> strain AO1, that degrades bisphenol A

Bisphenol A (2,2-bis(4-hydroxyphenyl) propane, BPA), which is used as a synthetic resin material or a plasticizer, is a pollutant that␣possesses endocrine-disrupting activity. Bioremediation of BPA is used to decrease its polluting effects, and here we report a novel bacterial strain AO1, which is able to degrade BPA. This strain was isolated using enrichment cultivation from a soil sample from a vegetable-growing field; the sample was one of 500 soil samples collected across Japan. Strain AO1 degraded 100 mg/l BPA to an undetectable level within 6 h in MYPG medium (containing malt extract, yeast extract, peptone, and glucose) and within 48 h in minimum medium containing 1% glucose at 30°C. Strain AO1 can utilize BPA as a sole source of carbon and as an energy source under aerobic conditions. The estrogenic activity of BPA in MYPG medium was ultimately reduced by strain AO1, although the activity initially increased. Taxonomical analysis showed that strain␣AO1 is closely related to Sphingomonas chlorophenolicum and S. herbicidovorans, neither of which have a capacity for BPA degradation. DNA–DNA hybridization showed that strain AO1 is a novel species of the Sphingomonas genus, and we designated AO1 as S. bisphenolicum.     

Growth and photosynthetic responses of <Emphasis Type="Italic">Fagus crenata</Emphasis> seedlings to O<Subscript>3 </Subscript>under different nitrogen loads

To obtain the basic data for evaluating the critical level of ozone (O₃) to protect Japanese deciduous broad-leaved forest tree species, the growth and photosynthetic responses of Fagus crenata seedlings to O₃ under different nitrogen (N) loads were investigated. The seedlings were grown in potted andisol supplied with N as NH₄NO₃ solution at 0, 20 or 50 kg ha⁻¹ year⁻¹ and were exposed to charcoal-filtered air or O₃ at 1.0, 1.5 and 2.0 times the ambient concentration for two growing seasons. The interactive effect of O₃ and N load on the whole-plant dry mass of the seedlings at the end of the second growing season was significant. The O₃-induced reduction in the whole-plant dry mass of the seedlings was greater in the relatively high N treatment than that in the low N treatment. This interactive effect was mainly due to the difference in the degree of O₃-induced reduction in net photosynthesis among the N treatments. The degree of O₃-induced reduction in N availability to photosynthesis was greater in the relatively high N treatment than that in the low N treatment. In conclusion, the sensitivity of growth and photosynthetic parameters of F. crenata seedlings to O₃ become high with increasing amounts of N added to the soil. Therefore, N deposition from the atmosphere should be taken into account to evaluate the critical level of O₃ to protect Japanese deciduous broad-leaved forest tree species.     

Structural advantage of dendritic poly(L-lysine) for gene delivery into cells

This study aimed to investigate the relationships between structures of gene carrier molecules and their activities for gene delivery into cells. We compared 2 types of poly(L-lysine) as carriers, that is, dendritic poly(L-lysine) (KG6) and linear poly(L-lysine) (PLL). KG6 formed a neutral DNA complex, and its DNA compaction level was weaker than that of PLL. The amount of DNA binding and uptake into cells mediated by PLL was 4-fold higher than that with KG6. However, KG6-mediated gene expression was 100-fold higher than that by PLL. Since pK(a) values of terminal amines of KG6 were lowered even though small amounts of DNA were internalized into cells, sufficient DNA amounts for effective gene expression escaped to the cytosol due to the proton sponge effect in the endosome. In addition, weakly compacted DNA with KG6 was advantageous in accessing RNA polymerase in the cell nucleus. On the other hand, PLL did not show the proton sponge effect in the endosome and resulted in strong compaction of DNA. Even though large DNA amounts were internalized into cells, most of the DNA would not take part in gene expression systems in the nucleus. Amount of induced cytokine production after intravenous injection of DNA complexes with KG6 and PLL was low, and was similar to the case when DNA was injected alone. Therefore, no significant difference in effects on cytokine production was observed between KG6 and PLL.     

Interleukin-1 is not essential for expression of inducible NOS in hepatocytes induced by lipopolysaccharide in vivo

Interleukin (IL)-1 and tumor necrotic factor alpha (TNFalpha) are pivotal in the pathogenesis of endotoxemia. In spite of the in vitro finding that IL-1beta, but not TNFalpha, can induce iNOS mRNA and NO production as a single stimulus in hepatocytes in primary culture, the involvement of IL-1 in iNOS induction in the liver has been less clear in vivo. To address this, we challenged IL-1alpha/beta double-knockout (IL-1alpha/beta(-/-)) and TNFalpha(-/-) mice with lipopolysaccharide (LPS). As compared with wild-type mice, the increases in the plasma NO level measured as nitrite and nitrate and hepatic iNOS were significantly reduced in IL-1alpha/beta(-/-) and TNFalpha(-/-) mice 8 and 12h after the LPS challenge. In the wild-type mice, iNOS protein was first detected in Kupffer cells around the portal vein 2h after LPS challenge; and then it spread to hepatocytes throughout the intralobular region of the liver by 8h. Although the expression of iNOS protein was detected in Kupffer cells of both IL-1alpha/beta(-/-) and TNFalpha(-/-) mice, its level was moderate in hepatocytes of IL-1alpha/beta(-/-) mice, but negligible in those of TNFalpha(-/-) mice, 8h after LPS challenge. Concomitant with the expression of iNOS protein in the liver, Toll-like receptor 4, the signaling receptor for LPS, was expressed in hepatocytes of wild-type and IL-1alpha/beta(-/-) mice, but not of TNFalpha(-/-) mice. These results demonstrate that the expression of Toll-like receptor 4 is well correlated with that of iNOS protein in hepatocytes in vivo after LPS challenge and that IL-1 is not essential for the induction of iNOS in hepatocytes in vivo.     

A ROCK inhibitor permits survival of dissociated human embryonic stem cells

Poor survival of human embryonic stem (hES) cells after cell dissociation is an obstacle to research, hindering manipulations such as subcloning. Here we show that application of a selective Rho-associated kinase (ROCK) inhibitor, Y-27632, to hES cells markedly diminishes dissociation-induced apoptosis, increases cloning efficiency (from approximately 1% to approximately 27%) and facilitates subcloning after gene transfer. Furthermore, dissociated hES cells treated with Y-27632 are protected from apoptosis even in serum-free suspension (SFEB) culture and form floating aggregates. We demonstrate that the protective ability of Y-27632 enables SFEB-cultured hES cells to survive and differentiate into Bf1(+) cortical and basal telencephalic progenitors, as do SFEB-cultured mouse ES cells.