Standardized memory tests and the appraisal of everyday memory.

Although ecological validity of traditional tests of memory has been questioned, use of these tests remains the standard in clinical practice. More recently, however, standardized measures with more emphasis on ecological relevance have been developed. One hundred and nineteen adults with diagnosed brain injuries completed traditional instruments of memory assessment, the Luria Nebraska Neuropsychological Battery Memory Scale (LNNB-M) and the Wechsler Memory Scale-Revised (WMS-R). Subjects also completed the Rivermead Behavioural Memory Test (RBMT), an instrument designed to measure everyday memory. Additionally, clinicians rated subjects' day-to-day memory functioning at the rehabilitation facility. Results suggest that RBMT is most accurate in classifying severity of memory impairment as rated by clinicians. The LNNB-M and WMS-R were relatively accurate at classifying severely impaired and unimpaired subjects, but were much less accurate at classifying subjects in the mild and moderate impairment ranges. Implications for interpretation and use of these instruments in rehabilitation settings are discussed.

Neuropsychological testing and functional outcome for individuals with traumatic brain injury.

The relationship between performance on neuropsychological measures and the vocational and independent living functioning of individuals with traumatic brain injury was examined. The Wechsler Adult Intelligence Scale-Revised (WAIS-R) IQ and Stroop Color and Word Test scores differentiated individuals who required no assistance with activities of daily living from those requiring some level of assistance. Only the Stroop Color and Word Test scores differentiated individuals who were competitively employed or engaged in degree-oriented education from those who were unemployed or in sheltered or supported employment. Wechsler Memory Scale-Revised (WMS-R) scores did not differentiate these groups.

Evaluation of a commercial polymerase chain reaction assay for the detection of Chlamydia trachomatis.

Cell culture has traditionally been considered the most sensitive method for detecting Chlamydia trachomatis from clinical specimens, but depends upon the organisms being viable at the time of cell inoculation. Furthermore, cell culture is slow and labor intensive. Even when a special transport medium is used, there is a progressive loss of viability of C. trachomatis during transport. The detection of C. trachomatis by cell culture is more rapid when immunofluorescence is used to detect early antigen, but requires considerable experience to interpret. The Amplicor C. trachomatis system is a commercial polymerase chain reaction (PCR)-based assay combined with nucleic acid hybridization for the direct detection of C. trachomatis in urine and swabs of appropriate sites, with results available within 6 h. All specimens for C. trachomatis received by the Royal Perth Hospital Department of Microbiology during the period 1 July 1994 to 30 June 1995 that were suitable for culture and Amplicor PCR were tested by both methods (2029 specimens). Discordant results were obtained in nine cases and resolved by additional testing. Seventy-one specimens were confirmed as true positives, of these Amplicor PCR correctly detected 67 (sensitivity 94.4%) and culture correctly detected 62 (sensitivity 87.3%). The Amplicor PCR assay was found to be more sensitive and as specific as culture. It had the added advantages of ease of use, rapid availability of results, standardization and was more suited than culture to processing large number of specimens.

Comparative evaluation of microplate enzyme-linked immunosorbent assay versus plaque reduction assay for antiviral susceptibility testing of herpes simplex virus isolates.

We tested the antiviral susceptibilities of 30 clinical isolates of herpes simplex virus using the microplate in situ enzyme-linked immunosorbent assay (MISE) and the plaque reduction assay (PRA). There was concordance for 26 of 30 acyclovir results and all 30 foscarnet results. MISE and PRA results each predicted the response to acyclovir in 12 of 14 instances and the response to foscarnet in 8 instances. MISE is more rapid than PRA, has an objective endpoint, and correlates well with the clinical response to therapy.

A blinded comparison of two methods of viral susceptibility testing: plaque reduction assay versus microplate in situ ELISA.

Viral susceptibility testing has been shown to have a role in the management of patients with herpes simplex infections. In this study, 25 isolates of herpes simplex virus representing a broad spectrum of acyclovir-susceptible and -resistant phenotypes were tested using a microplate in situ enzyme-linked immunosorbent assay (MISE). This method is objective and more rapid than the traditional plaque reduction assay (PRA). The previously derived PRA results were not known at the time of testing with the MISE method. The correlation coefficient between PRA and MISE was 0.85. Agreement on sensitive or resistant was reached for 21 of 25 isolates. The standardised microplate in situ ELISA was found to be an acceptable alternative to the plaque reduction assay.

Standardisation of a microplate in situ ELISA (MISE-test) for the susceptibility testing of herpes simplex virus to acyclovir.

Viral susceptibility testing has been traditionally performed by plaque reduction assay (PRA) which is labour intensive, time consuming and requires subjective input by the reader. An in situ enzyme-linked immunosorbent assay (ELISA) method has been developed with the potential to overcome many of the limitations of PRA, and has been applied to a variety of viruses. Previous reports of ELISA susceptibility assays have shown little standardisation between these methods, or any significant analysis of the variable factors which may influence the outcome of the assay. This study optimised the sensitivity of a microplate in situ ELISA (MISE-test) for the detection of viral growth, manipulated the interaction between cells, virus and acyclovir to determine the effect of their relationship on susceptibility results, and established standard assay conditions based on quality controlled parameters such as assay variability and linear ranges. 33 isolates of HSV-2 were tested for susceptibility to acyclovir by PRA, and the standardised MISE. Factors which were critical to the performance of the MISE included inoculum size, inoculation method, duration of incubation, fixative type, immunoglobulin working strengths and choice of chromogenic substrate. Using the ELISA it was possible to separate sensitive HSV-2 isolates from resistant isolates applying a cutoff ID50 value of 2.0 mg/l. The correlation coefficient between PRA and MISE was 0.65. The standardised microplate in situ ELISA was found to be an acceptable alternative to the plaque reduction assay.

Comparison of the RIM-H rapid identification kit with conventional tests for the identification of Haemophilus spp.

A commercially available system, the RIM-H system (Austin Biological Laboratories, Austin, Tex.), was evaluated for its ability to rapidly and accurately identify various Haemophilus spp. A total of 110 clinical isolates were tested by both the RIM and conventional identification procedures. The RIM agreed with the standard identification for 100% of the Haemophilus influenzae (76 of 76) and 92.0% of the Haemophilus parainfluenzae (23 of 25) isolates tested. The identifications of Haemophilus parahaemolyticus, Haemophilus aphrophilus, and Haemophilus haemolyticus also correlated with those obtained by conventional methods. The RIM was found to be rapid and easy to use and was considered a suitable alternative to conventional identification procedures.