Trends in the incidence rate of device-associated infections in intensive care units after the establishment of the Korean Nosocomial Infections Surveillance System

BACKGROUND

The effectiveness of continuous nationwide surveillance on healthcare-associated infections should be investigated in each country.

AIM

To assess the rate of device-associated infections (DAIs) in intensive care units (ICUs) since the establishment of the Korean Nosocomial Infections Surveillance System (KONIS).

METHODS

Nationwide data were obtained on the incidence rate of DAI in ICUs reported to KONIS by all participating hospitals. The three major DAIs were studied: ventilator-associated pneumonia (VAP), central line-associated bloodstream infection (CABSI), and catheter-associated urinary tract infection (CAUTI). The pooled and year-wise incidence rates (cases per 1000 device-days) of these DAIs were determined for the period 2006 and 2012. In addition, data from institutions that had participated in KONIS for at least three consecutive years were analysed separately.

FINDINGS

The number of ICUs participating in KONIS gradually increased from 76 in 2006 to 162 in 2012. Between 2006 and 2012, the incidence rate per 1000 device-days for VAP decreased significantly from 3.48 to 1.64 (F = 11, P < 0.01), for CAUTI the rate decreased non-significantly from 1.85 to 1.26 (F = 2.02, P = 0.07), and for CABSI the rate also decreased non-significantly from 3.4 to 2.57 (F = 1.73, P = 0.12). In the 132 ICUs that had participated in KONIS for at least three consecutive years, the VAP rate significantly decreased from the first year to third year (F = 20.57, P < 0.01), but the rates of CAUTI (F = 1.06, P = 0.35) and CABSI (F = 1.39, P = 0.25) did not change significantly.

CONCLUSION

The decreased incidence rate of VAP in ICUs in Korea might be associated with the continuous prospective surveillance provided by KONIS.

The prevalence of bronchiectasis in patients with Marfan syndrome

An association has been suggested between Marfan syndrome (MFS) and the nodular bronchiectatic form of lung disease caused by non-tuberculous mycobacteria (NTM). We evaluated the prevalence of bronchiectasis in 79 adult patients with MFS using computed tomography (CT) imaging. Airway dilation indicative of bronchiectasis (22/79, 28%) and bronchioloectasis (10/79, 13%) were relatively common, although the extent of dilation was not severe and was frequently confined to a single lobe. However, bronchiolitis was evident in only three patients (4%), and no patient was diagnosed with NTM lung disease.

Factors related with metastasis of right retroesophageal lymph nodes in papillary thyroid cancer

AIM

Right retroesophageal lymph nodes (RRLNs) should be involved in central lymph nodes (CLNs) dissection in patients with papillary thyroid cancer (PTC). This study assessed the incidence and factors related to RRLNs metastasis.

METHODS

From January 2008 to March 2010, 129 patients who underwent total thyroidectomy with CLNs dissection including RRLNs were enrolled. The predictive value of RRLNs metastasis was assessed.

RESULTS

Twenty six (20.1%) of 129 patients exhibited nodal metastasis in RRLNs. Metastasis of RRLNs was associated with large tumor size (>1 cm; P<0.01), multiplicity (P=0.03), preoperative LN enlargement (P<0.01), metastasis of non-retroesophageal lateral LN (P<0.01) and large number of CLNs metastases (P<0.01) in univariate analysis. Multivariate analysis revealed that tumor size (>1 cm) and metastasis of non-retroesophageal lateral LN were independent correlates of RRLNs metastases.

CONCLUSION

RRLNs may be removed during operation for PTC, particularly in patients with tumor >1 cm and lateral LN metastases.

Evolution of atomic structure in Al75Cu25 liquid from experimental and ab initio molecular dynamics simulation studies

X-ray diffraction and electrostatic levitation measurements, together with the ab initio molecular dynamics simulation of liquid Al(75)Cu(25) alloy have been performed from 800 to 1600 K. Experimental and ab initio molecular dynamics simulation results match well with each other. No abnormal changes were experimentally detected in the specific heat capacity over total hemispheric emissivity and density curves in the studied temperature range for a bulk liquid Al(75)Cu(25) alloy measured by the electrostatic levitation technique. The structure factors gained by the ab initio molecular dynamics simulation precisely coincide with the experimental data. The atomic structure analyzed by the Honeycutt-Andersen index and Voronoi tessellation methods shows that icosahedral-like atomic clusters prevail in the liquid Al(75)Cu(25) alloy and the atomic clusters evolve continuously. All results obtained here suggest that no liquid-liquid transition appears in the bulk liquid Al(75)Cu(25) alloy in the studied temperature range.

Andrographolide inhibits HMGB1-induced inflammatory responses in human umbilical vein endothelial cells and in murine polymicrobial sepsis

AIM

Nuclear DNA-binding protein high-mobility group box 1 (HMGB1) protein acts as a late mediator of severe vascular inflammatory conditions, such as septic shock, upregulating pro-inflammatory cytokines. Andrographolide (AG) is isolated from the plant of Andrographis paniculata and used as a folk medicine for treatment of viral infection, diarrhoea, dysentery and fever. However, the effect of AG on HMGB1-induced inflammatory response has not been studied.

METHODS

Firstly, we accessed this question by monitoring the effects of post-treatment AG on lipopolysaccharide (LPS) and caecal ligation and puncture (CLP)-mediated release of HMGB1 and HMGB1-mediated regulation of pro-inflammatory responses in human umbilical vein endothelial cells (HUVECs) and septic mice.

RESULTS

Post-treatment AG was found to suppress LPS-mediated release of HMGB1 and HMGB1-mediated cytoskeletal rearrangements. AG also inhibited HMGB1-mediated hyperpermeability and leucocyte migration in septic mice. In addition, AG inhibited production of tumour necrosis factor-α (TNF-α) and activation of AKT, nuclear factor-κB (NF-κB) and extracellular-regulated kinases (ERK) 1/2 by HMGB1 in HUVECs. AG also induced downregulation of CLP-induced release of HMGB1, production of interleukin (IL) 1β/6/8 and mortality.

CONCLUSION

Collectively, these results suggest that AG may be regarded as a candidate therapeutic agent for the treatment of vascular inflammatory diseases via inhibition of the HMGB1 signalling pathway.

The novel miR-9500 regulates the proliferation and migration of human lung cancer cells by targeting Akt1

MicroRNAs have crucial roles in lung cancer cell development. They regulate cell growth, proliferation and migration by mediating the expression of tumor suppressor genes and oncogenes. We identified and characterized the novel miR-9500 in human lung cancer cells. The miR-9500 forms a stem-loop structure and is conserved in other mammals. The expression levels of miR-9500 were reduced in lung cancer cells and lung cancer tissues compared with normal tissues, as verified by TaqMan miRNA assays. It was confirmed that the putative target gene, Akt1, was directly suppressed by miR-9500, as demonstrated by a luciferase reporter assay. The miR-9500 significantly repressed the protein expression levels of Akt1, as demonstrated via western blot, but did not affect the corresponding mRNA levels. Akt1 has an important role in lung carcinogenesis, and depletion of Akt1 has been shown to have antiproliferative and anti-migratory effects in previous studies. In the current study, the overexpression of miR-9500 inhibited cell proliferation and the expression of cell cycle-related proteins. Likewise, the overexpression of miR-9500 impeded cell migration in human lung cancer cells. In an in vivo assay, miR-9500 significantly suppressed Fluc expression compared with NC and ASO-miR-9500, suggesting that cell proliferation was inhibited in nude mice. Likewise, miR-9500 repressed tumorigenesis and metastasis by targeting Akt1. These data indicate that miR-9500 might be applicable for lung cancer therapy.

Endoscopic focal modulation microscopy

We present endoscopic focal modulation microscopy (FMM) for minimally invasive imaging of deep tissue with high contrast, and then compare the results using endoscopic confocal microscopy (CM). Deep tissue imaging is achieved using a needle-like endoscopic probe based on gradient-index (GRIN) lenses. A tissue-like phantom with fluorescent micro-beads and rat kidney tubules were imaged through the endoscopic probe with FMM. FMM effectively rejected the background signals from the out-of-focus plane, thereby enhancing the image contrast and the optical sectioning ability. The combination of the GRIN endoscopic probe and FMM provides deep tissue imaging with better contrast than endoscopic CM.

Electrical characteristics of 2D and 3D microelectrodes for high-resolution retinal prostheses

In order to provide high quality visual information to patients who have implanted retinal prosthetic devices, the number of microelectrode should be large. As the number of microelectrode is increased, the dimension of the microelectrode is decreased, which in turn results in the increased interface impedance of microelectrode and decreased dynamic range of injection current. In addition, the reduced maximum limit of injection current may not be sufficiently large to stimulate the ganglion cells in a retina. In order to improve the trade-off envelope between number of microelectrode and current injection limit, a 3D microelectrode structure can be used as an alternative. From the advancement of microfabrication technology, the fabrication of highly-accurate 3D structures with small dimensions is possible. This paper presents a first comprehensive electrical characterization of 2D and 3D microelectrodes for high-resolution retinal prostheses. Microelectrodes which differ in shapes and diameters are analyzed. Their interface impedances and charge injection limits are quantitatively analyzed. This research can be used to define requirements for further retinal prosthetic device research.

Volumetric response evaluation after intensity modulated radiotherapy in patients with supratentorial gliomas

Radiotherapy is frequently indicated to treat cerebral gliomas. Accurate response evaluation after radiotherapy is essential to determine the efficacy of treatment. We retrospectively analyzed the volumetric tumor response after simultaneous integrated boost-intensity modulated radiotherapy (SIB-IMRT) in patients with gliomas. Thirty-five patients (Grade II, 7 patients; Grade III, 12; and Grade IV, 16) were treated with SIB-IMRT with a median total dose of 55.9 Gy/26 fractions for Grade II and 60 Gy/25 fractions for Grade III-IV tumors. Tumor responses were evaluated for enhancing volume on post-gadolinium T1-weighted images (Vgd) and hyper-intensity volume on T2-weighted FLAIR images (V(fl)) on serial MRIs. With the median follow-up of 24.0 months, overall response rates (RRs) were 57% for V(gd) and 51% for V(fl). Tumor grade was predictive of response favoring the lower grade in Vfl with RRs of 86% for Grade II, 75% for Grade III, and 19% for Grade IV tumors (p = 0.004). Time to 50% or greater volume reduction (T50) in Vgd was 8 months for grade III. The T50 in V(fl) was approximately 24 months both for Grade II and III tumors. Majority of Grade IV tumors continued to progress and never reached the T50 in Vgd or Vfl. Responders survived longer than non-responders for V(gd) and V(fl). Volume response after radiotherapy was dependent upon tumor grade and time. LGGs are very responsive to radiotherapy with the RRs of 86% in V(fl). The response of Vfl is more protracted compared to V(gd). Further investigation is needed to determine the clinical significance of volumetric response evaluation.