Effects of bioaerosol exposure on respiratory health in compost workers: a 13-year follow-up study.

OBJECTIVES: To determine the risk of German compost workers developing chronic respiratory effects from long-term exposure to bioaerosols. METHODS: Respiratory health was determined in 74 currently exposed compost workers and 37 non-exposed controls after 13 years of follow-up. In addition, 42 former compost workers (drop-outs) who left their work during the follow-up period were also examined. Respiratory symptoms and working conditions were assessed using identical questionnaires as at baseline. In addition, lung function was measured using the same spirometer as in the initial study. Sera from both surveys were tested for specific IgE and IgG antibodies to moulds and the risk of work-related symptoms was evaluated using regression approaches for prospective studies with binary data. RESULTS: In the follow-up period, the number of participants reporting cough significantly increased in compost workers and drop-outs compared to the controls. Working as a compost worker for at least 5 years increased the relative risk for cough (RR 1.28; 95% CI 1.2 to 1.4) and for cough with phlegm (RR 1.32; 95% CI 1.2 to 1.5). Current and former compost workers had slightly lower predicted percentage of forced expiratory volume in 1 s and predicted percentage of forced vital capacity than controls, but decrease in lung function during follow-up was not different among the 3 groups. In addition, no significant changes could be detected in antibody concentrations. CONCLUSIONS: Our results suggest that chronic exposure to bioaerosols in composting plants is related to a significantly higher risk for cough with phlegm, indicating chronic bronchitis. However, compost workers showed no higher incidence of deterioration of pulmonary function over the study.

Evaluation of Airway Inflammation in Compost Workers Exposed to Bioaerosols Using Exhaled Breath Condensate and Fractional Exhaled Nitric Oxide.

Occupational bioaerosol exposures are capable to cause respiratory diseases. We studied the relationship between exposure to bioaerosols and biomarkers' concentration in exhaled breath condensate (EBC) and fractional exhaled nitric oxide (FeNO) in 119 bioaerosol-exposed compost workers taking into account atopy and smoking habits. Atopy was classified according to specific IgE concentrations to common inhalant allergens (sx1). Bioaerosol exposure was estimated according to job title, duration of employment, results of ambient monitoring at the workplaces, and shift time worked under protection of filtered air supply. Concentrations of 8-iso-prostaglandin F2α (8-iso-PGF2α), prostaglandin E2 (PGE2), leukotriene B4 (LTB4), and acid-base balance (pH) in EBC and FeNO were assessed in 59 never-smoking (NS) and 60 smoking (S) compost workers. We found that atopic subjects were equally distributed among NS and S (n=16 each). Levels of 8-iso-PGF2α were significantly higher in workers considered highly exposed to bioaerosols than in low exposed workers (86.6 (66.1; 128.8) pg/mL vs. 74.4 (56.3; 96.7) pg/mL, p=0.047). No associations could be observed between exposures and biomarkers concerning compost workers in total, but there were some in atopic workers (duration of employment and FeNO: r=0.376, p=0.041; filtered air supply and FeNO: r=-0.335, p=0.071). Smokers had significantly lower pH values compared to NS (non-atopic, p=0.041; atopic p=0.050). In conclusion, EBC and FeNO might be useful tools for monitoring of inflammation due to bioaerosol exposures, especially in atopic subjects. Besides smoking also atopy should be considered when investigating airway inflammation.

Virtual microscopy: high resolution digital photomicrography as a tool for light microscopy simulation.

Recent advances in microcomputers and high resolution digital video cameras provide pathologists the opportunity to combine precision optics with digital imaging technology and develop new educational and research tools. We review recent advances in virtual microscopy and describe techniques for viewing digital images using a microcomputer-based workstation to simulate light microscopic examination, including scanning at low power to select features of interest and zooming to increase magnification. Hardware and software components necessary to acquire digital images of histological and cytological slides, and closely simulate their examination under a light microscope are discussed. The workstation is composed of a MicroLumina digital scanning camera (Leaf Systems, Southborough, MA), light microscope (Olympus Optical Co., Lake Success, NY), Pentium (Intel Corp., Santa Clara, CA) 166 MHz microcomputer configured with 64 megabytes of random access memory (RAM), a MGA Millenium Powerdesk graphics card (Matrox Graphics, Inc., Montreal, Canada) and Photoshop software (Adobe Systems Inc., San Jose, CA) running in a Windows 95 (Microsoft Corp., Redmond, WA) environment. Images with spatial resolutions of up to 2700 x 3400 pixels in 36-bit color, can be displayed simultaneously as distinct images in a montage, or merged into a single composite image file to highlight significant features of a histological or cytological slide. These image files are saved in Joint Photographers Experts Group (JPEG) format using compression ratios of up to 80:1 without detectable visual degradation. The advantages and technical limitations of various workstation components are addressed and applications of this technology for pathology education, proficiency testing, telepathology, and database development are discussed.

Use of acidic and basic pH and calcium ion addition in the capillary zone electrophoretic characterization of recombinant human deoxyribonuclease, a complex phosphoglycoprotein.

This paper describes the analysis of recombinant human deoxyribonuclease (rhDNAse), an acidic and complex phosphoglycoprotein, by capillary zone electrophoresis (CZE). Separation performance was found to be dramatically improved by the addition of calcium ions to the CZE running buffer, due to the influence of calcium binding on the charge and the electrophoretic behavior of rhDNAse. The pH dependent calcium binding effects on the electrophoretic separation were demonstrated at both acidic and basic pH, resulting in a two-dimensional (pH 4.8 and 8.0) calcium aided analysis that achieved multipeak resolution of the complex, glycosylation based, charge microheterogeneity of rhDNAse. Two-dimensional investigation of neuraminidase- and alkaline phosphatase-digested protein further demonstrated that the acidic pH resolved acidic charge heterogeneity and that the basic pH discriminated neutral heterogeneity. This work demonstrates the resolving power of CZE for the analysis of a complex microheterogeneous glycoprotein, and emphasizes the importance of employing multiple separation conditions in accordance with known structural characteristics of the protein.

Virtual microscopy and public-key cryptography for Internet telepathology.

The Internet is a potentially inexpensive, widely available medium for telepathology, but there are concerns about its reliability and security. Using a digital camera, 41 photomicrographs of transbronchial biopsies, at x 100 optical magnification, were captured and digitized at 2700 x 3400 pixel, 24 bit/pixel resolution. The image files were saved in JPEG format at medium compression, attached to text files with patient information, encrypted for security in the S/MIME format using a digital signature and digital envelope, and transmitted by email. Received email files were decrypted automatically and the images viewed with standard software. Telepathology diagnoses were compared with original interpretations. The images averaged 810 kByte in size. The encryption and decryption did not cause significant delays in overall transmission time and, together with transmission, did not produce noticeable image degradation. The received image files could be viewed in a manner that simulated light microscopy. There was agreement between telepathology and original diagnoses in 92% of the cases. All the discrepancies were due to inadequate area selection because the pathological features of interest were present in histological levels other than those photographed. The use of high-resolution digital photomicrography, the Internet and public-key cryptography offers an effective and relatively inexpensive method of telepathology consultation. The method is best suited for the diagnosis of small biopsy specimens that require the transmission of only a few digital images that represent the majority of the biopsy materials.

Recent advances in DNA sequencing by capillary and microdevice electrophoresis.

A number of significant improvements in the electrophoretic performance and design of DNA sequencing devices have culminated in the introduction of truly industrial grade production scale instruments. These instruments have been the workhorses behind the massive increase in genomic sequencing data available in public and private databases. We highlight the recent progress in aspects of capillary electrophoresis (CE) that has enabled these achievements. In addition, we summarize recent developments in the use of microfabricated devices for DNA sequencing that promise to bring the next leap in productivity.

Automated high-throughput infusion ESI-MS with direct coupling to a microtiter plate.

This paper describes the design and application of instrumentation for automated high-throughput infusion ESI-mass spectrometry. The approach, based on a subatmospheric ESI interface, allows sample introduction from a commercially available microtiter plate without the need for a separate fluid delivery system. The microtiter plate was placed vertically on a three-dimensional translation stage in front of the sampling ESI interface. A single, 7-cm, 20-microm-i.d. fused-silica capillary (total volume, 70 nL), with a tapered tip, served as a combination of sample delivery and spraying capillary. The tapered tip of the capillary was enclosed in a subatmospheric chamber attached in front of the orifice of the mass spectrometer. The sample aspiration rate (flow rate) was regulated by computer-controlled pneumatic valves, which allowed fast switching of the pressure in the subatmospheric ESI chamber. A flow-through wash device was positioned between the microtiter plate and the ESI interface. This design allowed alternate filling of the capillary with (a) sample from the wells and (b) wash solution from the wash device. Sample turnaround times of 10 s/sample, with a 120-nL sample consumption/analysis, and a duty cycle (percentage of total analysis time spent acquiring data) of 40% were achieved. The infusion system was demonstrated in the analysis of preparative HPLC fractions from a small molecule combinatorial library.

Development of multichannel devices with an array of electrospray tips for high-throughput mass spectrometry.

The basic principles of multichannel devices with an array of electrospray tips for high-throughput infusion electrospray ionization mass spectrometry (ESI-MS) have been developed. The prototype plastic devices were fabricated by casting from a solvent-resistant resin. The sample wells on the device were arranged in the format of the standard 96-microtiter well plate, with each sample well connected to an independent electrospray exit port via a microchannel with imbedded electrode. A second plastic plate with distribution microchannels was employed as a cover plate and pressure distributor. Nitrogen gas was used to pressurize individual wells for transport of sample into the electrospray exit port. The design of independent microchannels and electrospray exit ports allowed very high throughput and duty cycle, as well as elimination of any potential sample carryover. The device was placed on a computer-controlled translation stage for precise positioning of the electrospray exit ports in front of the mass spectrometer sampling orifice. High-throughput ESI-MS was demonstrated by analyzing 96 peptide samples in 480 s, corresponding to a potential throughput of 720 samples/h. As a model application, the device was used for the MS determination of inhibition constants of several inhibitors of HIV-1 protease.

"Virtual microscopy" and the internet as telepathology consultation tools: diagnostic accuracy in evaluating melanocytic skin lesions.

The Internet offers a widely available, inexpensive tool for telepathology consultations. It allows the transfer of image and text files through electronic mail (e-mail) or file transfer protocols (FTP), using a variety of microcomputer platforms. We studied the use of the Internet and "virtual microscopy" tools for the diagnosis of 35 skin biopsies, including a variety of benign and malignant melanocytic lesions. Digitized images from these lesions were obtained at 40x and 100x optical magnification, using a high resolution digital camera (Microlumina, Leaf Systems, Southborough, MA), a light microscope with a phototube adapter and a microcomputer with a Pentium 166 MHz microprocessor. Two to four images of each case were arranged on a "canvas" to represent the majority or an entire biopsy level, using Photoshop software (Adobe Systems Inc., San Jose, CA). The images were compressed using Joint Photographers Expert Group (JPEG) format. The images were then viewed on a computer video monitor in a manner that closely resembles light microscopy, including scrolling by using the "hand tool" of Photoshop and changing magnification digitally up to 4 times without visible image degradation. The image files, ranging in size from 700 kilobytes to 2.1 megabytes (average 1.6 megabytes) were attached to e-mail messages that contained clinical information, using standard Multipurpose Internet Mail Extension (MIME) protocols and sent through the Internet, for interpretation by a dermatopathologist. The consultant could open the images from the e-mail message, using Microsoft Outlook Express (Microsoft Corp., Redmond, WA) and Photoshop software, scroll them, change magnification and render a diagnosis in a manner that closely simulates light microscopy. One hundred percent concordance was obtained between the telepathology and traditional hematoxylin and eosin slide diagnoses. The Internet and relatively inexpensive "virtual microscopy" tools offer a novel technology for dermatopathology consultations. Potential applications of this technology to pathology and technical problems posed by the use of an open, widely distributed network to share sensitive medical information are discussed.