High-throughput combinatorial cell co-culture using microfluidics.

Co-culture strategies are foundational in cell biology. These systems, which serve as mimics of in vivo tissue niches, are typically poorly defined in terms of cell ratios, local cues and supportive cell-cell interactions. In the stem cell niche, the ability to screen cell-cell interactions and identify local supportive microenvironments has a broad range of applications in transplantation, tissue engineering and wound healing.

Probing dynamic generation of hot-spots in self-assembled chains of gold nanorods by surface-enhanced Raman scattering.

Further progress in the applications of self-assembled nanostructures critically depends on developing a fundamental understanding of the relation between the properties of nanoparticle ensembles and their time-dependent structural characteristics. Following dynamic generation of hot-spots in the self-assembled chains of gold nanorods, we established a direct correlation between ensemble-averaged surface-enhanced Raman scattering and extinction properties of the chains. Experimental results were supported with comprehensive finite-difference time-domain simulations.

A nationwide seroprevalence of total antibody to hepatitis A virus from 2005 to 2009: age and area-adjusted prevalence rates.

Background/aims: Recent outbreak of hepatitis A in Korea is clearly related to the epidemiological shift of hepatitis A virus (HAV). However, nationwide seroprevalence data have been limited. This study estimated the nationwide, age- and area-adjusted anti-HAV prevalence from 2005 to 2009.

Topical prophylaxis for HIV prevention in women: becoming a reality.

Strategies to protect against sexual transmission of HIV include the development of products formulated for topical application, which limit the toxicities associated with systemic oral pre-exposure prophylaxis. Following several clinical trial failures, attention is now focused on antiretroviral (ARV) agents. Highly potent ARV topical formulations provide a female-controlled, targeted, and feasible option for HIV prevention.

Assessment of trending ability of cardiac output monitors by polar plot methodology.

Objectives: To develop a valid statistical method of showing acceptable cardiac output (CO) trending ability when new CO monitors are compared to a reference standard, such as thermodilution, using polar coordinates.

Design: Developing a new statistical analytic method using historic data.

Setting: University Hospital Anesthesia and Intensive Care Department.

A randomized trial to assess anti-HIV activity in female genital tract secretions and soluble mucosal immunity following application of 1% tenofovir gel.

Background: Preclinical and early phase clinical microbicide studies have not consistently predicted the outcome of efficacy trials. To address this gap, candidate biomarkers of microbicide pharmacodynamics and safety were evaluated in a double-blind, placebo-controlled trial of tenofovir gel, the first microbicide to demonstrate significant protection against HIV acquisition.

Methods: 30 women were randomized to apply a single daily dose of tenofovir or placebo gel for 14 consecutive days.

Attitudes towards ethical problems in critical care medicine: the Chinese perspective.

Introduction: Critical care doctors are frequently faced with clinical problems that have important ethical and moral dimensions. While Western attitudes and practice are well documented, little is known of the attitudes or practice of Chinese critical care doctors.

Methods: An anonymous, written, structured questionnaire survey was translated from previously reported ethical surveys used in Europe and Hong Kong.

Adrenergic regulation of AMP-activated protein kinase in brown adipose tissue in vivo.

AMP-activated protein kinase (AMPK), an evolutionarily conserved serine-threonine kinase that senses cellular energy status, is activated by stress and neurohumoral stimuli. We investigated the mechanisms by which adrenergic signaling alters AMPK activation in vivo. Brown adipose tissue (BAT) is highly enriched in sympathetic innervation, which is critical for regulation of energy homeostasis.

FLI-1 distinguishes Ewing sarcoma from small cell osteosarcoma and mesenchymal chondrosarcoma.

Small cell osteosarcoma and mesenchymal chondrosarcoma are 2 primary bone tumors with a small round blue cell component, which can mimic the appearance of Ewing sarcoma. Distinguishing these tumors from each other on biopsy material is important clinically, as optimal therapy differs according to the tumor type. However, separating these entities on morphology alone can be challenging.

A critical review of the ability of continuous cardiac output monitors to measure trends in cardiac output.

Numerous cardiac output (CO) monitors have been produced that provide continuous rather than intermittent readings. Bland and Altman has become the standard method for validating their performance against older standards. However, the Bland and Altman method only assesses precision and does not assess how well a device detects serial changes in CO (trending ability).

The costs and benefits of extending the role of the acute pain service on clinical outcomes after major elective surgery.

Background: Acute pain services have received widespread acceptance and formal support from institutions and organizations, but available evidence on their costs and benefits is scarce. Although there is good agreement on the provision of acute pain services after many major surgical procedures, there are other procedures for which the benefits are unclear. Data are required to justify any expansion of acute pain services.

Evaluation of an immunochromatographic assay for the detection of anti-hepatitis A virus IgM.

Background: Hepatitis A virus (HAV) is a causative agent of acute hepatitis, which is transmitted by person-to-person contact and via the faecal-oral route. Acute HAV infection is usually confirmed by anti-HAV IgM detection. In order to detect anti-HAV IgM in the serum of patients infected with HAV, we developed a rapid assay based on immunochromatography (ICA) and evaluated the sensitivity of this assay by comparing it with a commercial microparticle enzyme immunoassay (MEIA) that is widely used for serological diagnosis.

Determination and comparison of graded dose-response curves for epidural bupivacaine and ropivacaine for analgesia in laboring nulliparous women.

Background: The potencies of bupivacaine and ropivacaine have been compared using up-and-down methodology, but their complete dose-response curves have not been compared. The authors performed a random allocation-graded dose-response study of epidural bupivacaine and ropivacaine given epidurally for labor analgesia.

Methods: Three hundred laboring nulliparous patients were randomly given epidural bupivacaine (5, 10, 15, 20, 30, or 40 mg) or ropivacaine (7, 15, 20, 30, 45, or 60 mg) in 20 ml of saline.

Periodic acid-schiff is superior to hematoxylin and eosin for screening prophylactic gastrectomies from CDH1 mutation carriers.

Hereditary diffuse gastric cancer (HDGC), an autosomal dominant cancer susceptibility syndrome, is largely attributable to germline mutations and deletions in the gene encoding E-cadherin, CDH1. Asymptomatic, mutation-positive individuals often choose prophylactic gastrectomy for cancer risk reduction. Examination of the entire mucosa of prophylactic gastrectomy specimens is essential and shows occult gastric cancers in most cases.

Searching for signaling balance through the identification of genetic interactors of the Rab guanine-nucleotide dissociation inhibitor gdi-1.

Background: The symptoms of numerous diseases result from genetic mutations that disrupt the homeostasis maintained by the appropriate integration of signaling gene activities. The relationships between signaling genes suggest avenues through which homeostasis can be restored and disease symptoms subsequently reduced. Specifically, disease symptoms caused by loss-of-function mutations in a particular gene may be reduced by concomitant perturbations in genes with antagonistic activities.

Using illness scripts to teach clinical reasoning skills to medical students.

Background And Objectives: Most medical students learn clinical reasoning skills informally during clinical rotations that have varying quality of supervision. We conducted a randomized controlled trial to determine if a workshop that uses "illness scripts" could improve students' clinical reasoning skills when making diagnoses of patients portrayed in written scenarios.

Methods: In 2007--2008, 53 fourth-year medical students were randomly assigned to either a family medicine (intervention) or psychiatry (control) clerkship at The Chinese University of Hong Kong.

Reverse genetics in Candida albicans predicts ARF cycling is essential for drug resistance and virulence.

Candida albicans, the major fungal pathogen of humans, causes life-threatening infections in immunocompromised individuals. Due to limited available therapy options, this can frequently lead to therapy failure and emergence of drug resistance. To improve current treatment strategies, we have combined comprehensive chemical-genomic screening in Saccharomyces cerevisiae and validation in C.

[An epidemiological analysis of hepatitis A virus serologic markers during the recent four years in Korea].

Background: To establish effective preventive measures for hepatitis A virus (HAV) infection, a nationwide epidemiologic study on seroprevalence of anti-HAV and the disease prevalence is needed. The aim of this study was to analyze the recent sero-epidemiological changes of hepatitis A markers in Korea.

Methods: The results of 11,068 anti-HAV total and 32,360 anti-HAV IgM tests by electro-chemiluminescence immunoassay (ECLIA) that had been requested in recent four years (2005-2008) to a reference medical laboratory from 1,699 institutions nationwide were retrospectively analyzed according to the distribution of year, sex, and age groups.

Chemogenomic profiling predicts antifungal synergies.

Chemotherapies, HIV infections, and treatments to block organ transplant rejection are creating a population of immunocompromised individuals at serious risk of systemic fungal infections. Since single-agent therapies are susceptible to failure due to either inherent or acquired resistance, alternative therapeutic approaches such as multi-agent therapies are needed. We have developed a bioinformatics-driven approach that efficiently predicts compound synergy for such combinatorial therapies.

A biochemical genomics screen for substrates of Ste20p kinase enables the in silico prediction of novel substrates.

The Ste20/PAK family is involved in many cellular processes, including the regulation of actin-based cytoskeletal dynamics and the activation of MAPK signaling pathways. Despite its numerous roles, few of its substrates have been identified. To better characterize the roles of the yeast Ste20p kinase, we developed an in vitro biochemical genomics screen to identify its substrates.

Design of novel histone-derived antimicrobial peptides.

Previous studies have identified several naturally occurring antimicrobial peptides derived from histone proteins. This research aimed to design novel histone-derived antimicrobial peptides (HDAPs). To this end, three novel peptides (DesHDAP1, DesHDAP2, and DesHDAP3) were designed based on a histone-DNA crystal structure and structural properties of buforin II, the best characterized naturally occurring HDAP.

Pulmonary responses to subacute ozone exposure in obese vs. lean mice.

The purpose of this study was to determine whether obesity affects pulmonary responses following a 3-day ozone exposure. Obese db/db and lean wild-type mice were exposed to ozone (0.3 ppm) for 72 h.

Forecasting emergency department crowding: an external, multicenter evaluation.

Study Objective: We apply a previously described tool to forecast emergency department (ED) crowding at multiple institutions and assess its generalizability for predicting the near-future waiting count, occupancy level, and boarding count.

Methods: The ForecastED tool was validated with historical data from 5 institutions external to the development site. A sliding-window design separated the data for parameter estimation and forecast validation.

Lamellar envelopes of semiconductor nanocrystals.

We report the solution-phase formation of ordered lamellar nanocrystal (NC) arrays. These semiconductor lamellae exhibit structural integrity and temporal stability, without recourse to chemical cross-linking. They are many micrometers in diameter yet only two or three nanocrystal layers in thickness.