Regression discontinuity of blood culture contamination rate after changing of disinfectants: retrospective observational study.

Blood cultures are indispensable for detecting life-threatening bacteremia. Little is known about associations between contamination rates and topical disinfectants for blood collection in adults. We sought to determine whether a change in topical disinfectants was associated with the rates of contaminated blood cultures in the emergency department of a single institution. This single-center, retrospective observational study of consecutive patients aged 20 years or older was conducted in the emergency department (ED) of a university hospital in Japan between August 1, 2018 and September 30, 2020. Pairs of blood samples were collected for aerobic and anaerobic culture from the patients in the ED. Physicians selected topical disinfectants according to their personal preference before September 1, 2019; alcohol/chlorhexidine gluconate (ACHX) was mandatory thereafter, unless the patient was allergic to alcohol. Regression discontinuity analysis was used to detect the effect of the mandatory usage of ACHX on rates of contaminated blood cultures. We collected 2141 blood culture samples from 1097 patients and found 164 (7.7%) potentially contaminated blood cultures. Among these, 445 (20.8%) were true bacteremia and 1532 (71.6%) were true negatives. Puncture site disinfection was performed with ACHX for 1345 (62.8%) cases and with povidone-iodine (PVI) for 767 (35.8%) cases. The regression discontinuity analysis showed that mandatory ACHX usage was significantly associated with lower rates of contaminated blood cultures by 9.6% (95% confidence interval (CI): 5.0%-14.2%, P < 0.001). Rates of contaminated blood cultures were significantly lower when ACHX was used as the topical disinfectant.

Sites of blood collection and topical antiseptics associated with contaminated cultures: prospective observational study.

We aimed to determine whether puncture sites for blood sampling and topical disinfectants are associated with rates of contaminated blood cultures in the emergency department (ED) of a single institution. This single-center, prospective observational study of 249 consecutive patients aged ≥ 20 years proceeded in the ED of a university hospital in Japan during 6 months. Pairs of blood samples were collected for aerobic and anaerobic culture from all patients in the ED. Physicians selected puncture sites and topical disinfectants according to their personal preference. We found 50 (20.1%) patients with potentially contaminated blood cultures. Fifty-six (22.5%) patients were true bacteremia and 143 (57.4%) patients were true negatives. Multivariate analysis associated more frequent contamination when puncture sites were disinfected with povidone-iodine than with alcohol/chlorhexidine (adjusted risk difference, 12.9%; 95% confidence interval [CI] 8.8-16.9; P < 0.001). Sites of blood collection were also associated with contamination. Femoral and central venous with other sites were associated with contamination more frequently than venous sites (adjusted risk difference), 13.1% (95% CI 8.2-17.9; P < 0.001]) vs. 17.3% (95% CI 3.6-31.0; P = 0.013). Rates of contaminated blood cultures were significantly higher when blood was collected from femoral sites and when povidone-iodine was the topical antiseptic.

Xylogranin B: a potent Wnt signal inhibitory limonoid from Xylocarpus granatum.

Xylogranin B (2) was isolated from Xylocarpus granatum (Meliaceae) leaves, by use of a cell-based luciferase screening system targeting a Wnt signaling pathway. Compound 2 inhibited TCF/ß-catenin transcriptional activity (IC50 48.9 nM) and exhibited strong cytotoxicity against colon cancer cell lines. Compound 2 significantly decreased ß-catenin protein levels in nuclei but not in the cytosol. These results indicated that a decrease in ß-catenin levels in nuclei by 2 resulted in the Wnt signal inhibitory effects of 2.

Visualization of mitochondria in living cells with a genetically encoded yellow fluorescent protein originating from a yellow-emitting luminous bacterium.

We have visualized redox and structural changes in the mitochondria of yeast Saccharomyces cerevisiae as a eukaryotic cell model using a genetically encoded yellow fluorescent protein (Y1-Yellow) and conventional fluorescence microscopy. Y1-Yellow originating from a yellow emitting luminous bacterium Aliivibrio sifiae Y1 was fused with a mitochondria-targeted sequence (mt-sequence). Y1-Yellow fluorescence arising only from the mitochondrial site and the color of yellow fluorescence could be easily differentiated from cellular autofluorescence and from that of conventional probes. Y1-Yellow expressing S. cerevisiae made the yellow fluorescence conspicuous at the mitochondrial site in response to reactive oxygen species (ROS) transiently derived in the wake of pretreatment with hydrogen peroxide. Based on our observation with Y1-Yellow fluorescence, we also showed that mitochondria rearrange to form a cluster structure surrounding chromosomal DNA via respiratory inhibition by cyanide, followed by the generation of ROS. In contrast, uptake of an uncoupler of oxidative phosphorylation is not responsible for mitochondrial rearrangement. These results indicate the utility of Y1-Yellow for visualization of mitochondrial vitality and morphology in living cells.

Acute effect of soybean beta-conglycinin hydrolysate ingestion on appetite sensations in healthy humans.

A hydrolysate prepared from soybean beta-conglycinin reduced food intake through cholecystokinin release in rats; however, effects of the hydrolysate on human appetites are unknown. In this study, healthy volunteers ingested 3g of the beta-conglycinin hydrolysate (BconB) and/or a soy protein hydrolysate (HN) contained in a beverage or in a jelly. Appetite profiles (hunger, fullness and prospective consumption) after the ingestion and palatability of test jellies were recorded. Fullness was rated higher, and hunger was rated lower after BconB ingestion as compared to HN ingestion. These results demonstrate that 3g of BconB is effective to enhance fullness and reduce hunger sensations in healthy humans.

2-methoxy-1,4-naphthoquinone isolated from Impatiens balsamina in a screening program for activity to inhibit Wnt signaling.

A screening study using a luciferase assay to identify natural products which inhibit Wnt signaling was carried out. The bioassay-guided fractionation of aerial parts of a plant, Impatiens balsamina, led to the isolation of 2-methoxy-1,4-naphthoquinone (1) as an active compound. Compound 1 inhibited the TCF/ß-catenin (TOP) transcriptional activity (IC(50) 2.9 µM), while it decreased the transcriptional activity of FOP (mutated TCF-binding site)-transfected cells at >5 µM.

Anti-proliferative and apoptosis-inducible activity of Sarcodonin G from Sarcodon scabrosus in HeLa cells.

There is an ongoing search for plant-derived diterpenes, especially for diterpenes with anti-inflammatory activity that also have anti-proliferative effects on human cancer cells. A cyathane-type diterpene, Sarcodonin G (SG), isolated from the mushroom Sarcodon scabrosus and already reported to have anti-inflammatory activity, inhibited proliferation of HeLa cells to the greatest extent among 4 cyathane diterpenes tested. SG showed an IC50 (50% inhibition concentration) of 20 microM, estimated by MTT assay 2 days after culture of cells with the chemical. SG treatment of HeLa cells resulted in dose-dependent generation of apoptotic events such as DNA-laddering (< or =100 microM). Moreover, SG-treated HeLa cells showed activation of caspase-3 and caspase-9 and increase of Bax/Bcl-2 ratios, as analyzed by Western blot analysis. The anti-proliferative effects of SG treatment on HeLa cells were lessened by a caspase inhibitor, Z-VAD-FMK. SG also showed anti-proliferative effects toward 5 other human cancer cell lines with IC50 values of 20-40 microM. Because of these anti-proliferative effects via possible caspase activation, SG holds promise of being a novel anti-proliferative agent deserving further investigation.

[Airway management in tracheal stenosis caused by malignant goiter].

We report a case of malignant goiter with severe tracheal stenosis. The patient was a 61-year-old female, who had orthopnea on admission. Radiological examinations revealed a tracheal stenosis extending from 4.5 cm to 8 cm below the glottis; the smallest caliber being 5 mm. On the seventh day after admission, the patient complained of dyspnea even while sitting. An emergency tracheotomy was scheduled. While the patient was awake in a sitting position, a fiberscope was inserted endotracheally to confirm the intact inner surface of the trachea, and then an armored endotracheal tube (outer diameter 9.2 mm, inner diameter 6.5 mm) was inserted. Unexpectedly, the tube could be advanced through the stenosis without resistance. After induction of general anesthesia, the patient was placed in a supine position, and a tracheotomy was performed. This case demonstrates that, while intubation of the trachea through a stenosis is sometimes dangerous, it may be indicated when the inner surface of the trachea is intact and a tube with an inner diameter greater than 5 mm can then be placed.