Visible near infrared reflectance molecular chemical imaging of human ex vivo carcinomas and murine in vivo carcinomas.

SIGNIFICANCE: A key risk faced by oncological surgeons continues to be complete removal of tumor. Currently, there is no intraoperative imaging device to detect kidney tumors during excision. AIM: We are evaluating molecular chemical imaging (MCI) as a technology for real-time tumor detection and margin assessment during tumor removal surgeries. APPROACH: In exploratory studies, we evaluate visible near infrared (Vis-NIR) MCI for differentiating tumor from adjacent tissue in ex vivo human kidney specimens, and in anaesthetized mice with breast or lung tumor xenografts. Differentiation of tumor from nontumor tissues is made possible with diffuse reflectance spectroscopic signatures and hyperspectral imaging technology. Tumor detection is achieved by score image generation to localize the tumor, followed by application of computer vision algorithms to define tumor border. RESULTS: Performance of a partial least squares discriminant analysis (PLS-DA) model for kidney tumor in a 22-patient study is 0.96 for area under the receiver operating characteristic curve. A PLS-DA model for in vivo breast and lung tumor xenografts performs with 100% sensitivity, 83% specificity, and 89% accuracy. CONCLUSION: Detection of cancer in surgically resected human kidney tissues is demonstrated ex vivo with Vis-NIR MCI, and in vivo on mice with breast or lung xenografts.

New methods for the detection of orthopedic and other biofilm infections.

The detection and identification of bacteria present in natural and industrial ecosystems is now entirely based on molecular systems that detect microbial RNA or DNA. Culture methods were abandoned, in the 1980s, because direct observations showed that <1% of the bacteria in these systems grew on laboratory media. Culture methods comprise the backbone of the Food and Drug Administration-approved diagnostic systems used in hospital laboratories, with some molecular methods being approved for the detection of specific pathogens that are difficult to grow in vitro. In several medical specialties, the reaction to negative cultures in cases in which overt signs of infection clearly exist has produced a spreading skepticism concerning the sensitivity and accuracy of traditional culture methods. We summarize evidence from the field of orthopedic surgery, and from other medical specialties, that support the contention that culture techniques are especially insensitive and inaccurate in the detection of chronic biofilm infections. We examine the plethora of molecular techniques that could replace cultures in the diagnosis of bacterial diseases, and we identify the new Ibis technique that is based on base ratios (not base sequences), as the molecular system most likely to fulfill the requirements of routine diagnosis in orthopedic surgery.

An electronic hand hygiene surveillance device: a pilot study exploring surrogate markers for hand hygiene compliance.

OBJECTIVE: To evaluate the feasibility of using an electronic hand hygiene surveillance and feedback monitoring device. DESIGN: A 2-phase pilot study included initial direct observation of hand hygiene practices as part of routine hospital quality assurance (phase I) and subsequent monitoring using an electronic hand hygiene surveillance device (phase II). SETTING: A 700-bed tertiary care teaching hospital. PARTICIPANTS: Phase I included a convenience sample of healthcare workers. Phase II included 7 medical interns and 7 registered nurses recruited through email and at work-related meetings. METHODS: During phase I, healthcare workers were directly observed at patient room entry and exit during the period April through November 2008. During phase II, hand hygiene data were gathered through indirect observation using the electronic device during a 4-week period in August 2009. Twenty patient rooms were fitted with electronic trigger devices that signaled a reader unit worn by participants when they entered the room, and 70 dispensers for liquid soap or hand sanitizer were fitted with triggers that signaled the reader unit when the dispenser was used. The accuracy of the devices was checked by the principal investigator, who manually recorded his room entries and exits and dispenser use while wearing a reader unit. RESULTS: During phase I, hand hygiene occurred before room entry for 95 (25.1%) and after room exit for 149 (39.4%) of 378 directly observed patient room visits, for a cumulative composite compliance rate of 32.3%. Among the 378 room visits, 347 (91.8%) involved contact with the patient and/or environment. During phase II, electronic monitoring revealed a cumulative composite compliance rate of 25.5%. The electronic device captured 61 (98%) of 62 manually recorded room entries and 133 (95%) of 140 manually recorded dispensing events. CONCLUSIONS: The electronic hand hygiene surveillance device seems to be a practical method for routinely monitoring hand hygiene compliance in healthcare workers.

Gene expression differences in infected and noninfected middle ear complementary DNA libraries.

OBJECTIVES: To investigate genetic differences in middle ear mucosa (MEM) with nontypeable Haemophilus influenzae (NTHi) infection. Genetic upregulation and downregulation occurs in MEM during otitis media (OM) pathogenesis. A comprehensive assessment of these genetic differences using the techniques of complementary DNA (cDNA) library creation has not been performed. DESIGN: The cDNA libraries were constructed from NTHi-infected and noninfected chinchilla MEM. Random clones were picked, sequenced bidirectionally, and submitted to the National Center for Biotechnology Information (NCBI) Expressed Sequence Tags database, where they were assigned accession numbers. These numbers were used with the basic local alignment search tool (BLAST) to align clones against the nonredundant nucleotide database at NCBI. RESULTS: Analysis with the Web-based statistical program FatiGO identified several biological processes with significant differences in numbers of represented genes. Processes involved in immune, stress, and wound responses were more prevalent in the NTHi-infected library. S100 calcium-binding protein A9 (S100A9); secretory leukoprotease inhibitor (SLPI); beta(2)-microglobulin (B2M); ferritin, heavy-chain polypeptide 1 (FTH1); and S100 calcium-binding protein A8 (S100A8) were expressed at significantly higher levels in the NTHi-infected library. Calcium-binding proteins S100A9 and S100A8 serve as markers for inflammation and have antibacterial effects. Secretory leukoprotease inhibitor is an antibacterial protein that inhibits stimuli-induced MUC1, MUC2, and MUC5AC production. CONCLUSIONS: A number of genes demonstrate changes during the pathogenesis of OM, including SLPI, which has an impact on mucin gene expression; this expression is known to be an important regulator in OM. The techniques described herein provide a framework for future investigations to more thoroughly understand molecular changes in the middle ear, which will likely be important in developing new therapeutic and intervention strategies.