Emotion processing in Alzheimer's disease.

To date, there have been few studies of emotion processing in those suffering from Alzheimer's disease, yet this may have an important effect on the quality of life of both sufferers and their families. This paper describes an investigation of the relative changes in cognition and in recognition and identification of non-verbal communicative signals of emotion in those suffering from Alzheimer's disease, and seeks to address the implications for clinical practice. Twelve adults with a diagnosis of "probable" Alzheimer's disease and 12 matched older adult healthy comparison participants undertook a series of tasks involving face and prosody discrimination. Facial stimuli were presented on cards, and prosodic stimuli on audiotape. Scores were compared with a measure of general cognitive ability. There was a significant difference between the Alzheimer's disease group and healthy older adult group on emotion and cognition tasks respectively. However, the ability to recognize and identify non-verbal affect cues in emotional facial expression and emotional prosody was preserved relative to general cognitive ability in those suffering from Alzheimer's disease. In addition, there were no differences found in the recognition of different emotions (happiness, sadness, anger, fear or neutral). This relative sparing of non-verbal emotional processing skills has implications for provision of assessment and interventions based on the creation of effective forms of communication that are less reliant on cognitive ability.

Lack of correlation of in vitro amphotericin B susceptibility testing with outcome in a murine model of Aspergillus infection.

Amphotericin B has been the standard therapy for invasive aspergillosis since its introduction in 1957. It is only moderately effective. Many susceptibility tests have been used but little variation has been noted between strains. We have studied three strains of Aspergillus fumigatusand one of Aspergillus terreusin a neutropenic mouse model of invasive aspergillosis and attempted to correlate the variable efficacy in vivowith MICs generated by over 30 different susceptibility test formats. One strain of A. fumigatus(AF65) and the strain of A. terreus(AT49) were 'resistant' and the remaining two strains of A. fumigatus(AF210 and AF294) were 'susceptible' in vivo. Only AT49 had elevated MICs of amphotericin (MIC 2 mg/L) by 41 of 54 in vitrotesting systems. With each test format, including Etest, there was no distinction between MICs obtained for AF65, AF210 and AF294 (MICs 0.125-64 mg/L depending on the test). Thus despite extensive efforts we have been unable to correlate susceptible test results with in vivooutcome in A. fumigatusbut we have with A. terreus, with some test formats. This suggests that, at present, amphotericin B susceptibility testing of A. fumigatus is of limited clinical value and further work needs to be done to find testing systems that can identify the 'resistance' documented in vivo.

Molecular epidemiological study of Aspergillus fumigatus in a bone marrow transplantation unit by PCR amplification of ribosomal intergenic spacer sequences.

We have developed a PCR-based method for the subspecific discrimination of Aspergillus fumigatus types by using two primers designed to amplify the intergenic spacer regions between ribosomal DNA transcription units. The method permitted the reproducible discrimination of 11 distinct DNA types among a total of 119 isolates of A. fumigatus collected from patients and from the environment of a bone marrow transplantation (BMT) unit over a three-year period. Ten DNA types of A. fumigatus were isolated from patients in the BMT unit; eight of these types were also found in the hospital environment, and six of these were present in the unit itself. Thirteen BMT patients developed infection with one of three DNA types some months after these had first been found in the environment of the unit. In other instances, the same DNA types of A. fumigatus were isolated from BMT patients that were later recovered from the environment of the unit. Several DNA types of A. fumigatus were found in the hospital environment over an 18-month period. Molecular typing of multiple isolates of A. fumigatus, obtained from postmortem tissue samples, showed that one patient was infected with a single DNA type, but two others had up to three different DNA types. Our findings suggest that A. fumigatus infection in BMT recipients may be nosocomial in origin and underline the need for careful environmental monitoring of units in which high-risk patients are housed.

Correlation between in-vitro susceptibility testing to itraconazole and in-vivo outcome of Aspergillus fumigatus infection.

Given the increased choice of therapeutic agents and the rising incidence of serious invasive disease, it is important that reliable in-vitro methods for detecting antifungal drug resistance in Aspergillus spp. are developed. Six clinical isolates of Aspergillus fumigatus, obtained from patients in whom the clinical outcome was known, were selected for study. Each was used to examine a range of parameters affecting agar dilution and broth microdilution susceptibility test results. The in-vitro results were compared with outcome in a neutropenic mouse model of invasive aspergillosis. Groups of animals were treated with itraconazole at 25 mg/kg and 75 mg/kg and survival rates and organ burdens were determined. Itraconazole was efficacious against four isolates (susceptible) but failed for two (resistant) in the animal model of infection. Both the resistant isolates had been obtained from patients receiving itraconazole treatment with good serum concentrations of the drug. Conditions for the agar dilution test which produced results that correlated best with our in-vivo observations included the use of RPMI agar with L-glutamine buffered to pH 7 with MOPS, inoculated with 10(6)-10(7) conidia/mL and incubated for 48-72 h at 28 or 35 degrees C with a no-growth endpoint. Optimal conditions for the broth microdilution method included the use of RPMI medium with L-glutamine and 2% glucose buffered to pH 7 with MOPS, an inoculum of 2 x 10(5) conidia in 200 microL incubated for 48 h at 35 degrees C with a growth (or trace) endpoint. The MICs for the susceptible isolates were 0.12-1.0 mg/L and > or = 16 mg/L for the resistant isolates. With careful selection and standardization of test conditions it is possible to generate reproducible in-vitro susceptibility data for Aspergillus spp. that will predict clinical outcome.

In vitro studies of activity of voriconazole (UK-109,496), a new triazole antifungal agent, against emerging and less-common mold pathogens.

The in vitro activity of voriconazole was compared with that of itraconazole. Eighty-six isolates of pathogenic molds belonging to 23 species were tested by an agar dilution method in High Resolution medium. Voriconazole was more active than itraconazole against a number of hyaline molds, including several Fusarium spp. and Scedosporium prolificans. Voriconazole and itraconazole showed comparable good activity against several hyaline molds, including Penicillium marneffei and Scedosporium apiospermum, and a number of dematiaceous molds, including Bipolaris australiensis, Cladophialophora bantiana, several Exophiala spp., and several Fonsecaea spp. Our results suggest that voriconazole could be effective against a wide range of mold infections in humans.

The influence of sodium chloride and pH on the growth of Salmonella enteritidis PT4.

Sodium or potassium chlorides at concentrations of ca 2.0% (w/v) stimulated the growth of Salmonella enteritidis PT4 and PT6 but not PT8 in nutrient broth acidified to < or = 5.5 with acetic but not with citric, propionic or hydrochloric acids. Stimulation was noted also with an acidified defined medium. The most pronounced stimulation occurred with incubation at 37 degrees C. Supplementation of acidified nutrient broth with sucrose or glycerol had no effect on the growth of salmonellas.