Investigation on the transmission rate of carbapenemase-producing carbapenem-resistant Enterobacterales among exposed persons in a tertiary hospital using whole-genome sequencing.

BACKGROUND: To reduce transmission of carbapenemase-producing carbapenem-resistant Enterobacterales (CP-CRE), screening is recommended for patients sharing rooms with CP-CRE-detected patients and healthcare workers caring for them. AIM: The aim of this study was to investigate the transmission rate of CP-CRE among exposed people in a tertiary hospital using whole-genome sequencing. METHODS: This study was conducted in a 1751-bed tertiary teaching hospital from January 2017 to December 2019. Index patients were defined as those with positive results in CP-CRE tests during hospitalization. When an index patient was detected in a shared room, we performed CRE screening tests for patients whose stay overlapped with an index patient's stay for at least one day. Where a second case was found, healthcare worker contacts were also screened. CP-CRE were confirmed, and the carbapenemase type identified, by PCR. Whole-genome sequencing was used to compare isolates from index and exposed patients. RESULTS: During the study period, 47 index patients were identified, and they had been in contact with 152 patients in shared rooms and 54 healthcare workers. None of the healthcare workers had CRE. Among the 152 exposed patients, four patients had the same type of carbapenemases as their CP-CRE index patients and all of them were KPC. Whole-genome sequencing revealed that three of these four pairs showed genotypic accordance between the index and the exposed. CONCLUSION: The CP-CRE transmission rate among the exposed patients was calculated as 2.0% (= 3/152).

Rubber friction on road surfaces: Experiment and theory for low sliding speeds.

We study rubber friction for tire tread compounds on asphalt road surfaces. The road surface topographies are measured using a stylus instrument and atomic force microscopy, and the surface roughness power spectra are calculated. The rubber viscoelastic modulus mastercurves are obtained from dynamic mechanical analysis measurements and the large-strain effective modulus is obtained from strain sweep data. The rubber friction is measured at different temperatures and sliding velocities, and is compared to the calculated data obtained using the Persson contact mechanics theory. We conclude that in addition to the viscoelastic deformations of the rubber surface by the road asperities, there is an important contribution to the rubber friction from shear processes in the area of contact. The analysis shows that the latter contribution may arise from rubber molecules (or patches of rubber) undergoing bonding-stretching-debonding cycles as discussed in a classic paper by Schallamach.

Detection and characterization of hepatocellular carcinoma: value of dynamic CT during the arterial dominant phase with uniphasic contrast medium injection.

OBJECTIVE: Our goal was to assess the effect of dynamic CT during the arterial dominant phase with uniphasic injection of intravenous contrast material (5 ml/s) in the detection and characterization of hepatocellular carcinomas (HCCs). MATERIALS AND METHODS: Three-phase incremental dynamic CT was performed in 66 patients with 84 HCCs diagnosed by pathologic findings, characteristic angiographic findings, and clinical manifestations. One hundred fifty milliliters of nonionic contrast medium was administered intravenously by using a power injector at a flow rate of 5 ml/s for 30 s, and three-phase images were obtained at 20-45 s (arterial dominant phase), 55-80 s (portal venous phase), and 2-4 min (equilibrium phase) after the start of uniphasic intravenous injection. Three-phase images in 66 patients were compared and assessed for the detectability and enhancement pattern of the tumors. RESULTS: The arterial dominant phase images of dynamic CT showed a moderate to marked hyperattenuation in 73 (87%) of the 84 HCCs, isoattenuation in 6 (7%), and hypoattenuation in 5 (6%). The portal venous phase images showed hyperattenuation in 6 (7%), isoattenuation in 45 (54%), and hypoattenuation in 33 (39%). In the equilibrium phase, CT findings showed hypoattenuation in 67 (80%) and isoattenuation in 17 (20%). The detectability of HCCs in the arterial dominant, portal venous, and equilibrium phase was 93, 46, and 80%, respectively. The detectability of HCCs in the arterial dominant phase was significantly (p < 0.0001) superior to that in both the portal venous phase and the equilibrium phase. CONCLUSION: Dynamic CT during the arterial dominant phase with uniphasic injection of intravenous contrast medium (5 ml/s) is a useful method in the detection and characterization of HCCs.

Effect of red ginseng on natural killer cell activity in mice with lung adenoma induced by urethan and benzo(a)pyrene.

It was previously reported that red ginseng extract inhibited carcinogenesis by urethan, DMBA, and aflatoxin B1 [Yun et al: Cancer Detect Prevent 1983; 6:515-25]. In an attempt to investigate the mechanism of the anticarcinogenic effect of ginseng, the natural killer (NK) activity and the incidence of lung adenoma were followed over a period of 48 weeks postinjection with urethan or benzo(a)pyrene. The NK activity was markedly depressed from 4 weeks to 24 weeks after injection of carcinogens. This decreased NK activity was returned to the level of controls by administration of ginseng. At the same time, a lower incidence of lung adenoma was noted following administration of ginseng to urethan-injected mice. However, the lung adenoma induced by benzo(a)pyrene began to occur at 48 weeks in which NK activity had naturally declined to a level too low to be affected by ginseng, and administration of ginseng did not decrease the incidence. In conclusion, these results suggest that the anticarcinogenic effect of ginseng may be related to the augmentation of NK activity.