Evaluation of clinical thermometers for accuracy and reliability

The purpose of this study was to examine the accuracy and reliability of a wide range of clinical thermometry instruments and technologies. In a historical sense, the purpose of this study was to determine if the improvements in speed, ease of use, and safety realized in the last 100 years have been offset by a loss of accuracy and/or reliability. In view of current events, the purpose was to determine if the new generation of electronic, digital clinical thermometers could be used to replace the traditional glass/mercury thermometers. Nine clinical thermometers representing electronic, digital oral, and predictive oral; electronic, digital infrared tympanic; and liquid crystal urinary technologies were evaluated. Accuracy was determined by comparing the temperatures obtained from these test instruments with those of the reference, glass/mercury oral thermometer. Reliability was determined by test-retest evaluation. All of the thermometers evaluated were significantly less accurate when compared with the reference thermometer in this study. All of the test instruments significantly underestimated higher temperatures and overestimated lower temperatures. This study indicated that the improvements in safety, speed, and ease of use of the newer clinical thermometers have been offset by a loss in accuracy and reliability. It also indicated that the current generation of electronic, digital clinical thermometers, in general, may not be sufficiently accurate or reliable to replace the traditional glass/mercury thermometers.     

Factors Associated with Change in Sexual Transmission Risk Behavior over 3 Years among HIV-Infected Patients in Tanzania

Background

The reduction of HIV transmission risk behaviors among those infected with HIV remains a major global health priority. Psychosocial characteristics have proven to be important correlates of sexual transmission risk behaviors in high-income countries, but little attention has focused on the influence of psychosocial and psychological factors on sexual transmission risk behaviors in African cohorts.

Methodology and Principal Findings

The CHAT Study enrolled a representative sample of 499 HIV-infected patients in established HIV care and 267 newly diagnosed HIV-infected individuals from the Kilimanjaro Region of Tanzania. Participants completed in-person interviews every 6 months for 3 years. Using logistic random effects models to account for repeated observations, we assessed sociodemographic, physical health, and psychosocial predictors of self-reported unprotected sexual intercourse. Among established patients, the proportion reporting any recent unprotected sex was stable, ranging between 6–13% over 3 years. Among newly diagnosed patients, the proportion reporting any unprotected sex dropped from 43% at baseline to 11–21% at 6–36 months. In multivariable models, higher odds of reported unprotected sex was associated with female gender, younger age, being married, better physical health, and greater post-traumatic stress symptoms. In addition, within-individual changes in post-traumatic stress over time coincided with increases in unprotected sex.

Conclusions and Significance

Changes in post-traumatic stress symptomatology were associated with changes in sexual transmission risk behaviors in this sample of HIV-infected adults in Tanzania, suggesting the importance of investing in appropriate mental health screening and intervention services for HIV-infected patients, both to improve mental health and to support secondary prevention efforts.     

Denitrification and nitrate-reducing bacterial populations in abandoned and reclaimed minesoils

Abstract Microbial populations, nitrogen mineralization potentials, and denitrification enzyme activities were examined in two abandoned carbolithic minesoils. Numbers and activities of bacteria and fungi were lower in nonamended than in lime and/or fly ash amended sites. Rates of aerobic NO₃⁻ production (3 to 38 μg-N kg⁻¹ h⁻¹) and anaerobic NO₃⁻ reduction to N₂O (5 to 68 μg-N kg⁻¹ h⁻¹) were measured. Organisms capable of N₂O production under anaerobic soil conditions were present in low numbers, and their activity was restricted in part by low soil pH. Nondenitrifying nitrate-reducing bacteria were more diverse and in greater numbers than respiratory denitrifiers and may have been responsible for N₂O production in assays measuring denitrification enzyme activity.     

An allosteric potentiator of M4 mAChR modulates hippocampal synaptic transmission

Muscarinic acetylcholine receptors (mAChRs) provide viable targets for the treatment of multiple central nervous system disorders. We have used cheminformatics and medicinal chemistry to develop new, highly selective M4 allosteric potentiators. VU10010, the lead compound, potentiates the M4 response to acetylcholine 47-fold while having no activity at other mAChR subtypes. This compound binds to an allosteric site on the receptor and increases affinity for acetylcholine and coupling to G proteins. Whole-cell patch clamp recordings revealed that selective potentiation of M4 with VU10010 increases carbachol-induced depression of transmission at excitatory but not inhibitory synapses in the hippocampus. The effect was not mimicked by an inactive analog of VU10010 and was absent in M4 knockout mice. Selective regulation of excitatory transmission by M4 suggests that targeting of individual mAChR subtypes could be used to differentially regulate specific aspects of mAChR modulation of function in this important forebrain structure.     

Macrophage proinflammatory response to Francisella tularensis live vaccine strain requires coordination of multiple signaling pathways

The macrophage proinflammatory response to Francisella tularensis (Ft) live vaccine strain (LVS) was shown previously to be TLR2 dependent. The observation that intracellular Ft LVS colocalizes with TLR2 and MyD88 inside macrophages suggested that Ft LVS might signal from within the phagosome. Macrophages infected with LVSDeltaiglC, a Ft LVS mutant that fails to escape from the phagosome, displayed greatly increased expression of a subset of TLR2-dependent, proinflammatory genes (e.g., Tnf) but decreased expression of others (e.g., Ifnb1). This latter subset was similarly mitigated in IFN-beta(-/-) macrophages indicating that while Ft LVS-induced TLR2 signaling is necessary, cytosolic sensing of Ft to induce IFN-beta is required for full induction of the macrophage proinflammatory response. Although LVSDeltaiglC greatly increased IL-1beta mRNA in wild-type macrophages, protein secretion was not observed. IL-1beta secretion was also diminished in Ft LVS-infected IFN-beta(-/-) macrophages. rIFN-beta failed to restore IL-1beta secretion in LVSDeltaiglC-infected macrophages, suggesting that signals in addition to IFN-beta are required for assembly of the inflammasome and activation of caspase-1. IFN-beta plays a central role in controlling the macrophage bacterial burden: bacterial recovery was greater in IFN-beta(-/-) than in wild-type macrophages and treatment of Ft LVS-infected macrophages with rIFN-beta or 5,6-dimethylxanthenone-4-acetic acid, a potent IFN-beta inducer, greatly decreased the intracellular Ft LVS burden. In toto, these observations support the hypothesis that the host inflammatory response to Ft LVS is complex and requires engagement of multiple signaling pathways downstream of TLR2 including production of IFN-beta via an unknown cytosolic sensor and activation of the inflammasome.     

Detection of Acinetobacter spp. in rural drinking water supplies.

A bacteriological survey was conducted of untreated, individual groundwater supplies in Preston County, W.Va. Nearly 60% of the water supplies contained total coliforms in excess of the U.S. Environmental Protection Agency maximum contaminant level of 1 CFU/100 ml. Approximately one-third of the water systems contained fecal coliforms and/or fecal streptococci. Acinetobacter spp. were detected in 38% of the groundwater supplies at an arithmetic mean density of 8 CFU/100 ml and were present in 16% of the water supplies in the absence of total coliforms, posing some concern about the usefulness of total coliforms as indicators of the presence of this opportunistic pathogen. Slime production, a virulence factor for A. calcoaceticus, was not significantly different between well water isolates and clinical strains, suggesting some degree of pathogenic potential for strains isolated from groundwater. In addition, several Acinetobacter isolates were able to interfere with sheen production by some coliform bacteria on M-Endo medium, adding further to the possible significance of Acinetobacter spp. in groundwater supplies.     

Formaldehyde degradation by catalytic oxidation.

Formaldehyde used for the disinfection of a laminar-flow biological safety cabinet was oxidatively degraded by using a catalyst. This technique reduced the formaldehyde concentration in the cabinet from about 5,000 to about 45 mg/m3 in 8 h. This technique should prove useful in other applications.     

Detection and identification of groundwater bacteria capable of escaping entrapment on 0.45-micron-pore-size membrane filters.

Rural drinking water systems supplied by untreated groundwater were examined to determine whether coliform or heterotrophic plate count bacteria are capable of escaping entrapment on standard porosity (0.45-micron-pore-size) membrane filters. Filterable bacteria were present in 42% of the 24 groundwater sources examined by using nonselective media (R2A, full strength m-HPC, and 0.1x m-HPC agars). Pseudomonads were the most frequently identified group of filterable bacteria detected. Flavobacterium, Alcaligenes, Acinetobacter, and Achromobacter isolates were also identified. Total coliforms were not recovered from any of the 24 groundwater samples following filtration through 0.45-micron-pore-size membrane filters by using selective M-Endo LES agar or mT7 agar. In addition, none of the isolates identified from nonselective media were coliforms. Similarly, neither total coliforms nor specifically Escherichia coli were detected in these filtrates when Colilert P/A medium was used.