Biomedical subjects
Publications and source records attributed to A C Peters.
We report an instance of progressive multifocal leukoencephalopathy in which cytarabine administration was successful as demonstrated by clinical course and follow-up computerized tomography studies. In this case, simian virus 40 (SV40) antigen was demonstrated in CSF cells by the indirect immunofluorescence technique.
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In nine out of 11 patients with herpes zoster and neurological symptoms varicella-zoster antigen was demonstrated in CSF cells by indirect immunofluorescent staining. Cerebrospinal fluid cytology was in most cases highly suggestive of viral infection. This study demonstrates the value of both immunofluorescent staining on CSF cells and CSF cytology, as corroboration of an otherwise exclusively serologically based virological diagnosis.
ECHO virus 25 focal encephalitis was documented for the first time in a 5-year-old boy with unequivocal hemichorea. Hemichorea caused by enterovirus CNS disease has never been reported. ECHO virus antigen in cerebrospinal fluid (CSF) cells was demonstrated by the indirect immunofluorescent technique and typed by a significant rise in neutralizing antibodies against ECHO virus 25. Sequential computerized tomographic (CT) studies with digital analysis demonstrated the evolution of a focal process in the head of the left caudate nucleus, ultimately leading to replacement of tissue by a CSF-containing cyst. In the unclarified pathogenesis of cerebral disease in enterovirus infection, this case suggests a focal inflammatory process rather than vasculitis, occlusion, and infarction. Finally, the near-complete recovery of our patient demonstrated that the mere loss of neostriatal tissue was not decisive in itself, because the tissue loss was permanent and the symptoms were transient.
In two cases of varicella-associated cerebellar ataxia, varicella-zoster antigens in CSF cells were shown by an indirect immunofluorescent technique. Direct viral invasion in CNS disease complicating varicella plays an important part in pathogenesis and rules out a single immune-mediated mechanism.
Among 162 children referred with head injury (in a 3-year period) a viral meningoencephalitis was proven to be present in seven cases. Only one patient showed symptoms of infection before the accident. On admission classical signs of viral meningoencephalitis were absent or mixed with the complications of head injury. A diagnosis of viral meningitis/meningoencephalitis was documented by immunofluorescent demonstration of viral antigens in CSF cells and/or pattern of CSF cytology and/or conventional serological methods. Whether the trauma and the infection are coincidental or causally related can not be decided definitively. A hypothesis is presented suggesting diminished alertness in subclinical viral meningoencephalitis, leading to accident proneness.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The minimum bacterial detection limits and operator reproducibility of the Biotrace Clean-Tracetrade mark Rapid Cleanliness Test and traditional hygiene swabbing were determined. Areas (100 cm2) of food grade stainless steel were separately inoculated with known levels of Staphylococcus aureus (NCTC 6571) and Escherichia coli (ATCC 25922). Surfaces were sampled either immediately after inoculation while still wet, or after 60 min when completely dry. For both organisms the minimum detection limit of the ATP Clean-Tracetrade mark Rapid Cleanliness Test was 10(4) cfu/100 cm2 (p < 0.05) and was the same for wet and dry surfaces. Both organism type and surface status (i.e. wet or dry) influenced the minimum detection limits of hygiene swabbing, which ranged from 10(2) cfu/100 cm2 to >10(7) cfu/100 cm2. Hygiene swabbing percentage recovery rates for both organisms were less than 0.1% for dried surfaces but ranged from 0.33% to 8.8% for wet surfaces. When assessed by six technically qualified operators, the Biotrace Clean-Tracetrade mark Rapid Cleanliness Test gave superior reproducibility for both clean and inoculated surfaces, giving mean coefficients of variation of 24% and 32%, respectively. Hygiene swabbing of inoculated surfaces gave a mean CV of 130%. The results are discussed in the context of hygiene monitoring within the food industry.
Six Salmonella strains were grown on two-dimensional sodium chloride-pH and temperature-pH gradient plates. Using image analysis the results were expressed in the form of three-dimensional wire frame graphs. On the temperature-pH gradient plates the optimum growth range was 20-30 degrees C and the minimum pH for visible growth was ca. pH 4, except for strain S. typhimurium CRA63 which grew over a narrower temperature and pH range. On the NaCl-pH gradient plates (whose NaCl gradient began at 2.75% (w/v) NaCl) the maximum concentration of salt at which growth was visible varied from 3.9% to 6.0%, and the minimum pH at which growth was observed varied from pH 4.7 to 5.4 according to the strain used. The incorporation of 0.02% (w/v) sodium nitrite reduced the maximum salt concentration and increased the minimum pH at which the strains could grow. The strains were combined and used in a mixed inoculum on NaCl-pH gradient plates containing 6 different concentrations of NaNO2 incubated at 6 different temperatures. Comparison of the data from the mixed inoculum with data from individual strains showed that, apart from one case, the mixed inoculum represented the extremes of the growth domains of the individual strains. The effect of NaNO2 on the ability of the strains to grow at different pH, NaCl concentrations and temperatures, was more clearly shown by subtracting the data of plates containing NaNO2 from the data of plates without NaNO2.
Errors and corrections made by 64 mildly epileptic children of at least average intelligence who were attending ordinary elementary schools when writing in response to dictation (writing-to-dictation) were assigned to one of 28 descriptive error categories. Numbers and types of errors were compared with those obtained in 630 form-matched, healthy control subjects (Wilcoxon's two-sample test, less than or equal to 0.01). Epileptic children made significantly more errors than control subjects. Separate error categories had no diagnostic power. The groups could not be distinguished on the basis of skill-related errors. However, performance errors (erroneous deviations from the intended product), were found to be made more frequently by epileptic children. Epileptic children made more corrections and also left more errors uncorrected than control children. No relationship could be established with illness variables. Deficient problem-solving strategies, probably resulting from emotional concomitants of epilepsy, may explain the results.
To compare the effects on attention and vigilance of conventional carbamazepine (CBZ) and CBZ controlled release (CBZ-CR), 15 schoolchildren with epilepsy and normal intelligence receiving CBZ were switched to CBZ-CR. Psychological examination was performed on the day before (day A) and 1 month after substitution (day B). Measurements of attention and vigilance were repeated throughout the day at 2-h intervals. Both on days A and B, CBZ plasma levels were monitored during a 12-h period. Fifteen matched healthy controls were submitted to identical test programs, allowing comparisons within subjects as well as between patients and control children. Variability of performance over sessions was neither increased nor decreased with CBZ-CR. Consistent differences over sessions did not exist between patients and controls with either drug. No relation was noted between reaction time and CBZ plasma level. The pharmacologic data confirm results of earlier studies in children. We noted a reduction in intradose fluctuations of CBZ level with CBZ-CR as compared with conventional CBZ. The neuropsychological results do not show a difference between the drugs. Neither were differences noted with respect to antiepileptic efficacy and side effects. At the end of the study, all but one of the children (and their parents) opted to receive CBZ-CR for ease of dosage administration and overall satisfaction.
Although the child behavior checklist (CBCL) and the teacher's report form (TRF) were not designed for diagnosing psychopathology in children with chronic illnesses, they have become extensively used research tools to assess behavioural problems in paediatric populations, including children with epilepsy. When applied to children with epilepsy, items like "staring blankly" or "twitching" can be rated on the basis of seizure features rather than behaviour and, hence, render behavioural scores ambiguous. The aims were detection, and evaluation of the impact, of CBCL and TRF items eliciting ambiguity when applied to children with "epilepsy only" (idiopathic or cryptogenic epilepsy, attending normal schools). Experts identified items that give rise to interpretational ambiguity of the ratings in epilepsy. By treating ratings on these items as missing values, their effect was evaluated in CBCL and TRF scores of 59 schoolchildren with "epilepsy only" and age and gender matched healthy classmates. Seven items of the CBCL gave rise to ambiguity of which items 5 co-occur on the TRF. Rescoring reduced psychopathology scores in children with "epilepsy only", but not in those of healthy children: the percentage of patients trespassing the clinical cut off score, on at least one of the subscales, reduced from 46 to 23% on the CBCL and from 18 to 15% on the TRF. Parents and teachers run the risk of confusing behaviour and seizure features when filling out the CBCL and TRF. In "epilepsy only", prevalence estimates of psychopathology based on the CBCL and TRF, should be considered with some reserve.