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Biomedical subjects

R Rogers

Publications and source records attributed to R Rogers.

At least 163 records · Page 9Linked to original sources

The resistance to re-infection of cats repeatedly inoculated with infective larvae of Brugia pahangi.

Seven microfilaraemic and five amicrofilaraemic cats which had been repeatedly infected with Brugia pahangi were challenged along with normal cats 28, 14 and 1 day before autopsy. The lymphatics of the amicrofilaraemic cats contained no female adult worms originating from the repeat infections and only two adult males (both from the same cat). Only 5.2% of the worms in the control cats were recovered from the amicrofilaraemic cats. Most of the challenge worms were killed in the first 24 h. The microfilaraemic cats all contained fertile adult male and female worms derived from the repeated infection but in such low numbers as to indicate considerable resistance to infection. Compared to their controls 26.4% of the challenge worms were recovered. Analysis of the life-cycle stages recovered showed that in both groups there was attrition of all stages and that although a number of worms reached L5 these were all killed later in the amicrofilaraemic cats.

Animals↗

Identification of random responders on MMPI protocols.

In clinical practice, indicators of random or irrelevant responses on MMPI protocols are typically not examined, and, if obtained, assumed to be the result of either gross psychopathology or attempts to malinger. A sample of 40 computer-generated random profiles and 40 profiles of forensic outpatients were compared on validity scales, clinical scales, and scales specially designed to detect randomness (TR index and Carelessness Scale). Results of discriminant analysis indicated differentiating patterns of responses with random profiles generally elevated. Further, the accuracy of several clinical decisions rules were evaluated. The "F greater than 80 and TR greater than 4" rule was found to have the greatest clinical utility at correctly classifying random responders.

Female↗

Scientific inquiry in forensic psychiatry.

Forensic psychiatry and psychology, with an extensive history of clinical practice, is only recently emerging as a new scientific specialty. It is confronted with both general scientific-methodological issues, as well as unique, empirically-based psycholegal applications. Aimed towards a broader, more flexible paradigm for understanding the basis of our scientific inquiry, the paper examines various research and methodological issues. As a model for connecting and understanding these complicated and interrelated issues, Holton's explicit and useful model of scientific structure is provided. The methodology, logical and statistical analysis, and themata are explored with regards to their potential impact on scientific inquiry in forensic psychiatry. This paper argues for several considerations in furthering research. From a methodological basis, the prospective researcher has to consider (1) whether the methodology is, in part, predetermining the results; (2) whether the results are a prediction of the inclusion criteria rather than an independent finding; (3) what balance between specificity and generalizability is designed within the research study; and (4) what is the impact of various methodological artifacts on the results and conclusions of forensic psychiatric research (e.g., demand characteristics, evaluation apprehension, experimenter bias, systems influence). Further, the forensic psychiatric researcher is asked to consider the basis of the "validity" of his research findings in comparison with "objective reality" from the perspective of logical and statistical analysis. Scientists within forensic psychiatry are asked to consider (1) whether to employ "best fit" or complementarity in understanding their results; (2) how to make explicit the steps in data transformation and redefinition within their study; (3) what are the implications of exclusive use of null hypothesis testing in establishing research results; and (4) what is the comparative utility of non-parametric and multivariate statistical procedures in studying and understanding experimental variables. Finally, in acknowledging the non-linear and sometimes self-justifying aspect of science, researchers are invited to examine their basic assumptions, and the self-perpetuating and constraining nature of unacknowledged themata, as well as their impact on forensic psychiatry. This paper is conceptualized as a movement towards articulating both general methodological issues and their unique application to forensic psychiatry. The brief exposition of Holton's model and review of illustrative research in forensic psychiatry constitutes one attempt to strengthen the scientific rigor of forensic psychiatric research.

Forensic Psychiatry↗

A computerized assessment program for forensic science evaluations: a preliminary report.

The development of the innovative use of an on-line, computer-assisted evaluation program is discussed, with a brief review of pertinent literature. The particular applications within a forensic psychiatric center of the Tandem 16 computer system, utilizing both "canned psychological tests" and specialized assessment techniques, are examined and highlighted with a case vignette. A highly relevant problem within forensic psychiatry, malingering or exaggeration of symptoms, is examined in more detail as it relates to computer assessments. The advantages and limitations of a computer-assisted evaluation are described relative to both its clinical and research application.

Adult↗

An empirical approach to insanity evaluations.

Described the development of the Rogers Criminal Responsibility Assessment Scales (RCRAS) as an empirically based testing procedure specifically designed for use in insanity evaluations. A pretest of the RCRAS that employed 10 case vignettes and a preliminary study of 25 patients are reported. Initial results indicated that the RCRAS has satisfactory interrater reliability and successfully discriminated between those patients evaluated as sane and insane. Results of the discriminant analysis, MANOVA, and factor analysis are discussed with reference to the RCRAS' construct validity and the need for further extensive studies.

Diagnosis, Differential↗

Successful vaccination of cats against Brugia pahangi with larvae attenuated by irradiation with 10 krad cobalt 60.

Cats were vaccinated by the inoculation on 10 occasions of approximately 300 larvae of Brugia pahangi which had been irradiated with 10 krad cobalt 60. They were challenged on 3 occasions with normal larvae of either B. pahangior B. patei. The vaccinated cats were resistant to challenge as demonstrated by either longer pre-patent periods or failure to become microfilaraemic and by having fewer third, fourth or adult worms than normal controls. Although the vaccination procedure was unpractically heavy these results lend encouragement to the possibility of developing vaccines against filarial infections.

Animals↗

Studies with Brugia pahangi. 20. An investigation of 23 anthelmintics using different screening techniques.

23 anthelmintics were tested against Brugia pahangi microfilariae and infective larvae in vitro and in Aedes aegypti infected with B. pahagi and jirds (Meriones unguiculatus) infected with a B. pahangi/patei hybrid. There was little correlation between the results obtained in vitro and in infected insects and the results obtained in these tests gave no indication of the activity in jirds. Three of the compounds were macrofilaricidal in jirds and these were tested in cats infected with B. pahangi. One of these--5-benzamido-2(4-thiazolyl)-benzimidazole--was macrofilaricidal in cats and it is suggest that it should be tested in other filarial systems. It is concluded that the insect and in vitro tests are not good primary screens for filaricidal activity.

Aedes↗

Intrauterine development of the microfilariae of Dipetalonema viteae.

The egg shell of Dipetalonema viteae separated from the oolemma and became highly convoluted at an early stage of development. No second oolemma or trilaminate membrane was seen. Channels containing electron dense material (thought to be nutrient material from the uterine wall) were formed between adjacent embryos. Many developing embryos died. Microvilli were formed by the uterine wall and developing embryos were closely apposed to these (again presumably to obtain nutrient). Embryos emerged from the egg in the uterus and were born as unsheathed microfilariae.

Animals↗