Dimensional clinical phenotyping using brain donor medical records: RDoC profiling is associated with Alzheimer's disease neuropathology.

Introduction: Transdiagnostic dimensional phenotypes are essential to investigate the relationship between continuous symptom dimensions and pathological changes. This is a fundamental challenge to work, as assessments of phenotypic concepts need to rely on existing records.

Methods: We adapted well-validated methodologies to compute National Institute of Mental Health Research Domain Criteria (RDoC) scores using natural language processing (NLP) from electronic health records (EHRs) obtained from brain donors and tested whether cognitive domain scores were associated with Alzheimer's disease neuropathological measures.

Dimensional clinical phenotyping using post-mortem brain donor medical records: Association with neuropathology.

Introduction: Transdiagnostic dimensional phenotypes are essential to investigate the relationship between continuous symptom dimensions and pathological changes. This is a fundamental challenge to postmortem work, as assessment of newly developed phenotypic concepts needs to rely on existing records.

Methods: We adapted well-validated methodologies to compute NIMH research domain criteria (RDoC) scores using natural language processing (NLP) from electronic health records (EHRs) obtained from post-mortem brain donors and tested whether RDoC cognitive domain scores were associated with hallmark Alzheimer's disease (AD) neuropathological measures.

Biohazards of investigations on the transmissible spongiform encephalopathies.

There is considerable current interest in the agents that cause the spongiform encephalopathies: scrapie, transmissible mink encephalopathy, kuru, and Creutzfeldt-Jakob disease (CJD). The unusual properties of these agents, their elusiveness, and their pathogenicity for humans (in the cases of kuru and CJD) make these agents interesting subjects of investigation but also make imperative a consideration of their potential biohazards in the laboratory. In view of both the potential pathogenicity of these agents and the potential hazards of many laboratory procedures, a series of physical containment levels, each of which corresponds to a range of composite risk factors, are suggested.

Infection of mice by aerosols of Klebsiella pneumoniae under hyperbaric conditions.

Both the physical behavior of aerosols and survival of airborne Serratia marcescens in hyperbaric chambers with a helium-air mixture at 20 atm of pressure was approximately the same as in the system at ambient pressures. Exposure of mice to aerosols of Klebsiella pneumoniae at 1-, 2-, and 17-atm (ca. 101-, 203-, and 1,722-kPa) pressures of helium-oxygen mixture showed that the number of viable organisms constituting a 50% lethal dose was not significantly affected by the hyperbaric conditions.

Evaluation of a class III biological safety cabinet for enclosure of an ultracentrifuge.

An evaluation of a special safety cabinet housing a high-speed centrifuge was made. The cabinet enclosed both the top access port and the drive and pumping machinery of the centrifuge. A titanium rotor was loaded with tubes containing a bacterial culture, weakened, and driven until rotor rupture occurred.

Evidence for more than one division of bacteria within airborne particles.

When the protocol that we had used to demonstrate a single division of bacterial cells in airborne particles was changed to one that increased the glycerol content of the atomizer fluid from 1 to 5% (vol/vol), thus producing larger particles, more than two (and nearly three) divisions of bacteria occurred within 6 h of aerosol time.

Evidence that bacteria can form new cells in airborne particles.

Serratia marcescens incubated for 8 h at 31 degrees C in a chemically defined medium contained in shake flasks was aerosolized into rotating-drum aerosol chambers at 30 degrees C and saturated humidity. Cells furnished tryptone (Difco) and glycerol just before aerosolization increased (in viable numbers and countable cells) almost twofold within 1 to 2 h after becoming airborne, whereas cells not furnished additional tryptone decreased in viable numbers at a faster rate than the number of particles removed by gravitational settling. Limited tests with a Coulter Counter showed that cell volume changes occurred in growing cells that did not occur in the nongrowing population.

Evidence for incorporation of thymidine into deoxyribonucleic acid in airborne bacterial cells.

As part of an effort to discover whether bacteria might propagate within airborne particles, we studied the incorporation of thymidine into the trichloroacetic acid-insoluble fraction of airborne cells of Serratia marcescens to seek evidence of the possible formation of new DNA. Two aerosols, one of S. marcescens and another of [3H]thymidine ([3H]dT) suspended in growth medium were caused to aggregate in air just prior to directing the aerosols into rotating-drum aerosol storage chambers.

Evidence for propagation of aerobic bacteria in particles suspended in gaseous atmospheres.

One factor involved in the possibility that airborne microbes might contaminate the Jovian atmosphere, is whether microbes have the capacity to propagate in air. Prior to these studies, the evidence was that the airborne state was lethal to microbes. By mixing an aerosol of aerobic bacteria with another containing 14C glucose, we were able to detect the presence of 14CO2, showing that the airborne cells were metabolically active.

Evaluation of Moloney murine sarcoma and leukemia virus complex as a model for airborne oncogenic virus biohazards: survival of airborne virus and exposure of mice.

Aerosols of the Moloney murine sarcoma virus (MuSV-M) and leukemia virus (MuLV-M) complex (MuSV-M/MuLV-M) were generated from refluxing atomizers and then aged in rotating drums at 21 degrees C holding temperature with relative humidities ranging from 25 to 76%. The MuSV-M and MuLV-M aerosolized from the same tumor extract preparation survived almost equally at the four humidity levels. Both viruses remained viable in the airborne state for at least 2 hours after aerosolization.