Search PubMed⌕ Search

Biomedical subjects

A C Peters

Publications and source records attributed to A C Peters.

At least 37 records · Page 2Linked to original sources
PubMed1998

The first unprovoked, untreated seizure in childhood: a hospital based study of the accuracy of the diagnosis, rate of recurrence, and long term outcome after recurrence. Dutch study of epilepsy in childhood.

OBJECTIVE: To assess the accuracy of the diagnosis of a first unprovoked seizure in childhood, the recurrence rate within two years, the risk factors for recurrence, and the long term outcome two years after recurrence. METHODS: One hundred and fifty six children aged 1 month to 16 years after a first seizure, and 51 children with a single disputable event were followed up. The diagnosis of a seizure was confirmed by a panel of three child neurologists on the basis of predescribed diagnostic criteria. None of the children was treated after the first episode. RESULTS: Five children with a disputable event developed epileptic seizures during follow up. The diagnosis did not have to be revised in any of the 156 children with a first seizure. The overall recurrence rate after two years was 54%. Significant risk factors were an epileptiform EEG (recurrence rate 71%) and remote symptomatic aetiology and/or mental retardation (recurrence rate 74%). For the 85 children with one or more recurrences, terminal remission irrespective of treatment two years after the first recurrence was >12 months in 50 (59%), <six months in 22 (26%), and six to 12 months in 11 (13%) and unknown in two (2%). Taking the no recurrence and recurrence groups together, a terminal remission of at least 12 months was present in 121 out of the 156 children (78%). CONCLUSIONS: The diagnosis of a first seizure can be made accurately with the help of strict diagnostic criteria. The use of these criteria may have contributed to the rather high risk of recurrence in this series. However, the overall prognosis for a child presenting with a single seizure is excellent, even if treatment with antiepileptic drugs is not immediately instituted.

Adolescent↗
PubMed1998

Randomized prospective study of early discontinuation of antiepileptic drugs in children with epilepsy.

We studied recurrence rate, risk factors for recurrence, and outcome after recurrence in children after early withdrawal of antiepileptic drugs (AEDs). One hundred sixty-one children with newly diagnosed epilepsy who had become seizure free within 2 months after starting treatment and remained so for 6 months were randomly assigned to immediate withdrawal of AEDs (n = 78) or continuation of treatment for another 6 months followed by withdrawal (n = 83). The probability of remaining seizure free at 24 months after randomization was 51% (95% CI, 40 to 62) in Group A and 52% (41 to 63) in Group B. Significant predictive factors for relapse were partial epilepsy, seizure onset at 12 years or older, defined etiology, and epileptiform EEG before randomization. At the end of follow-up (median, 41.9 months), 129 children (80.6%) had a terminal remission of at least 1 year, 88 without AEDs and 41 with AEDs. No significant difference in outcome was found between Groups A and B. In children with epilepsy and an early response to therapy, AED withdrawal after 6 or 12 months of treatment leads to seizure recurrence in approximately half of all patients regardless of the duration of therapy. More than 60% of those with one or more recurrences reach a terminal remission of at least 1 year after long-term follow-up with or without AEDs.

Adolescent↗
PubMed1997

The growth of Salmonella typhimurium on irradiated, raw, skinless chicken breast.

Salmonella typhimurium was inoculated onto 1 g cubed samples of irradiated, raw, skinless chicken breast, which were then incubated at 30 degrees C under humid conditions. Kinetic growth data was obtained by means of viable counts performed on triplicate samples over a 24 h period. In addition, the spatial arrangement of cells on samples taken 6, 12 and 24 h after inoculation was observed by scanning electron microscopy. The population entered exponential growth approximately 3 h after inoculation, and maintained a constant rate of growth for approximately 13 h before entering a stationary phase. A generation time of 0.74 h was recorded. Scanning electron microscopy observations revealed colonial development from loose clusters of cells at 6 h to discrete, compact microcolonies (approximately 40 microns in diameter) by 12 h. By 24 h colonies were well-developed (approximately 600-700 microns in diameter) with a well-defined colony periphery. The results of this study give insight into the growth and development of bacteria on meat tissue, and serve to highlight that the nature of such growth is quite different from that in dispersed liquid culture systems, i.e. those traditionally used to model such growth.

Animals↗
PubMed1997

Clinical course of untreated tonic-clonic seizures in childhood: prospective, hospital based study.

OBJECTIVE: To assess decleration and acceleration in the disease process in the initial phase of epilepsy in children with new onset tonic-clonic seizures. STUDY DESIGN: Hospital based follow up study. SETTING: Two university hospitals, a general hospital, and a children's hospital in the Netherlands. PATIENTS: 204 children aged 1 month to 16 years with idiopathic or remote symptomatic, newly diagnosed, tonic-clonic seizures, of whom 123 were enrolled at time of their first ever seizure; all children were followed until the start of drug treatment (78 children), the occurrence of the fourth untreated seizure (41 children), or the end of the follow up period of two years (85 untreated children). MAIN OUTCOME MEASURES: Analysis of disease pattern from first ever seizure. The pattern was categorised as decelerating if the child became free of seizures despite treatment being withheld. In cases with four seizures, the pattern was categorised as decelerating if successive intervals increased or as accelerating if intervals decreased. Patterns in the remaining children were classified as uncertain. RESULTS: A decelerating pattern was found in 83 of 85 children who became free of seizures without treatment. Three of the 41 children with four or more untreated seizures showed a decelerating pattern and eight an accelerating pattern. In 110 children the disease process could not be classified, mostly because drug treatment was started after the first, second, or third seizure. The proportion of children with a decelerating pattern (42%, 95% confidence interval 35% to 49%) may be a minimum estimate because of the large number of patients with an uncertain disease pattern. CONCLUSIONS: Though untreated epilepsy is commonly considered to be a progressive disorder with decreasing intervals between seizures, a large proportion of children with newly diagnosed, unprovoked tonic-clonic seizures have a decelerating disease process. The fear that tonic-clonic seizures commonly evolve into a progressive disease should not be used as an argument in favour of early drug treatment in children with epilepsy.

Adolescent↗
PubMed1997

Growth inhibitory effects of liposome-associated 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphocholine.

The growth inhibitory effects of 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphocholine (ET-18-OCH3) and various liposome compositions of ET-18-OCH3 were compared in a standardized growth inhibition assay utilizing a diverse tumor cell line panel including cell lines expressing multidrug resistance. ET-18-OCH3 and ELL-12 (4:3:1:2, dioleoylphosphatidylcholine/ cholesterol/dioleoylphosphatidylethanolamine-glutaric acid/ET-18-OCH3), an optimal liposomal ET-18-OCH3 formulation, inhibited growth in the micromolar range in drug-sensitive and -resistant cells. In general, ET-18-OCH3-liposomes were about twofold less growth inhibitory than ET-18-OCH3. However, the known hemolytic effects of ET-18-OCH3 were greatly reduced, up to 20 or more times, by liposome association. The effects of ET-18-OCH3 and ELL-12 were compared in intracellular [Ca2+] modulation and DNA fragmentation assays. ET-18-OCH3 elicited both concentration- and serum-dependent transient and permanent increases in intracellular [Ca2+]. In contrast, ELL-12 did not modulate intracellular [Ca2+]. ET-18-OCH3 and ELL-12 similarly affected DNA fragmentation, which may be indicative of apoptosis. The results suggest that, although the specific growth inhibitory effects of ET-18-OCH3 and ELL-12 are similar, associating ET-18-OCH3 with stable well-characterized liposomes eliminates nonspecific cell membrane-associated lytic effects.

Animals↗
PubMed1997

Disability due to restrictions in childhood epilepsy.

Parents and doctors impose restrictions on children with epilepsy to avoid seizure-related injuries. We intended to quantify disability due to such restrictions by using a newly developed parent-completed 10-item scale (The Hague Restrictions in Childhood Epilepsy Scale, HARCES). Parents reported disability on at least one item of the HARCES in 83% of 122 children with epilepsy and a remission from seizures for less than 1 year. Psychometric analysis of the scale's reliability demonstrated good internal consistency and retest stability. Its validity was supported by the association between HARCES scores and the physicians' advice imposing restrictions. We found no substantial association with such variables as seizure type, short-term remission, or seizure activity. These findings suggest that in children with recurrent seizures, restrictions were probably not optimally adapted to seizure-related risks. A repeat test after 1 year showed that a seizure remission of more than 1 year substantially reduced restrictions, which is probably associated with an improvement in quality of life.

Adolescent↗
PubMed1997

Seizure severity in children with epilepsy: a parent-completed scale compared with clinical data.

PURPOSE: We wished to compare a parent-completed scale quantifying seizure severity (SS) in children with various seizure types with the clinicians' impression of SS and other clinical data. METHODS: The parents of 117 children with recurrent seizures completed a 13-item, subjective scale (The Hague Seizure Severity Scale, HASS). Eight treating neurologists quantified SS on a 10-point Visual Analog Scale (VAS) and supplied other clinical data. RESULTS: Both the HASS and the VAS assessments of SS showed considerable variation within one seizure type. Significant differences were noted between groups with (a) absences and simple partial seizures (SPS), (b) complex partial seizures (CPS), and (c) generalized tonic-clonic seizures (GTCS). The correlation coefficient between the neurologists' and the parents' scores was 0.45 but did not exceed 0.26 after stratification for seizure type. The parents' score was not substantially influenced by various other clinical variables. The neurologists' score was correlated with resistance to treatment and presence of mental retardation. CONCLUSIONS: The SS ratings of the parents and the neurologists were not substantially correlated. The consideration that parents, as eyewitnesses to the seizures, are probably better judges of SS than clinicians may favor the use of a parent-completed scale to quantify SS. The HASS is a valid and reliable measure of parent-perceived SS that can be useful as an outcome measure in childhood epilepsy.

Age Factors↗
PubMed1997

The diagnostic yield of a second EEG after partial sleep deprivation: a prospective study in children with newly diagnosed seizures.

PURPOSE: To assess the diagnostic yield of a repeated EEG (REPEEG) after partial sleep deprivation (SD) in children and adolescents with one or more seizures who previously had had a standard EEG (STDEEG) without epileptiform abnormalities (EAs). In the literature, 32-75% of such REPEEGs after SD were reported to show EA. METHODS: In a prospective, multicentred study, we selected children aged 1 month to 16 years with one or more idiopathic or remote symptomatic newly diagnosed seizures. A REPEEG was recorded in children without EAs in their STDEEG. RESULTS: Of 552 children and adolescents who entered the study, 243 (44%) had a STDEEG without EAs. In 177 (73% of eligible children), REPEEGs were recorded after SD. We found EAs in 61 (34.5%) REPEEGs and new nonepileptiform abnormalities in five (1%). In 552 children in the total cohort, the REPEEG thus added 11% with EAs to the 56% with EAs in the STDEEG. Of REPEEGs, 81% included sleep compared with 20% of STDEEGs. In about half the REPEEGs, EAs occurred during sleep only. One child had tonic-clonic seizures probably related to the SD. CONCLUSIONS: One third of REPEEGs yielded new diagnostic information. Partial, age-dependent SD was highly effective in inducing sleep, which is important because in many cases EAs were found only during EEG recording in sleep. The procedure was safe and convenient.

Adolescent↗
PubMed1996

Parent-completed scales for measuring seizure severity and severity of side-effects of antiepileptic drugs in childhood epilepsy: development and psychometric analysis.

We have developed two outcome measures for childhood epilepsy: a seizure severity (SS) scale and a side-effects (SE) scale. Both scales have been designed for completion by parents. The scales were tested in two pilot phases and the results of this stepwise analysis are described here. The final scales' psychometric properties were assessed in a group of 80 children with active epilepsy, representative of the population at whom the scales were aimed: children with chronic epilepsy, aged 4-16 years, including all seizure types and epilepsies, as well as children with neurological comorbidity. The SS scale and SE scale showed good internal consistency and test-retest stability. Although there was a significant positive correlation between the SS scale and the SE scale, this was low, indicating that the scales measure a different clinical trait. The SE scale consisted of two subscales: a Toxic subscale, measuring the severity of dose-related side-effects, and a Chronic subscale, measuring the severity of long-term behavioural and cognitive side-effects. These subscales for side-effects showed a high correlation and can be used as a joint scale. These scales have the potential to improve outcome assessment in childhood epilepsy and they can be used to assess important aspects of quality of life in this population.

Adolescent↗
PubMed1996

The outcome of absence epilepsy: a meta-analysis.

We performed a meta-analysis of studies on absence epilepsy (AE) to ascertain whether the outcome of this well-defined type of epilepsy can be stated unequivocally. Using the Index Medicus and Medline CD+, we identified 1,619 publications. After applying the criteria of the International League against Epilepsy (ILAE) for AE, 26 publications on 23 study cohorts with a total of 2,303 patients were included. Remission rates ranged from 0.21 to 0.89; they differed substantially due to heterogeneity between the studies in inclusion criteria, methods, follow-up length, and outcome definitions. One half of the patients developed generalized tonic-clonic seizures (TCS) in the course of the disease. The proportion seizure free was 0.78 for patients with absence seizures (AS) only, and 0.35 for those who developed TCS. The outcome of AE may be worse than previously stated due to the considerable proportion of patients developing TCS in the course of their disease. Early prediction of outcome in patients who present with AS cannot be provided with certainty.

Adolescent↗
PubMed1995

The effect of sodium chloride concentration and pH on the growth of Salmonella typhimurium colonies on solid medium.

The growth of Salmonella typhimurium colonies on a model food system (agar solidified culture medium) was followed. Colony radius, determined using computer image analysis (IA) techniques, and viable cell number per colony were measured as indices of colony growth, and the effect of [NaCl] (0.5-3.5% (w/v)) and pH (7.0-5.0) on colony growth at 30 degrees C was observed; colonies were point inoculated from serial dilutions. Colony growth (between 13 and 26 h after inoculation) was linear when expressed in terms of radius, and exponential when expressed in terms of viable cell number per colony. Overall, both increasing the [NaCl] and decreasing the pH had little effect on colony growth, other than to delay the onset of linear radial growth. Initial specific growth rate (mu) ranged from 0.73 to 0.87 h-1. Thin films of agar medium on microscope slides allowed the growth of microcolonies to be observed after just 4 h incubation. A greater understanding of the growth kinetics of bacterial colonies, and the effects of environment on such data, may enable better control of foodborne bacterial pathogens, and consequently an improvement in food product safety.

Agar↗
PubMed1995

Paroxysmal phenomena in the first two years of life.

The prevalence of paroxysmal phenomena in the first two years of life was assessed in 1854 children of Dutch-speaking mothers of a population-based birth cohort. At each visit to the Child Health Clinic (CHC), mothers were asked whether they had noted sudden change of consciousness, involuntary movements, deviation of the eyes or apnoea, and if so, whether these appeared to be related to feeding. Paroxysmal episodes occurred in a quarter of the children: in 8 per cent only in relation to feeding, in 19 per cent also not related to feeding. The latter children were more frequently admitted to hospital and had more disabilities at age two years. No connection with epilepsy in the family or with congenital anomalies could be demonstrated. Special attention should be paid by the CHC team to children with paroxysmal phenomena not associated with feeding.

Birth Weight↗
PubMed1995

The syndrome of autosomal recessive pontocerebellar hypoplasia, microcephaly, and extrapyramidal dyskinesia (pontocerebellar hypoplasia type 2): compiled data from 10 pedigrees.

The syndrome of autosomal recessive pontocerebellar hypoplasia, microcephaly, severely impaired mental and motor development, and extrapyramidal dyskinesia is a distinct system degeneration, previously designated pontocerebellar hypoplasia type 2 (PCH-2). To further characterize its clinical and neuroimaging features, we compiled data from 10 nonrelated pedigrees. Six pedigrees were Dutch, two Swedish, and two German. All 16 patients showed an identical profile of virtually absent developmental milestones, early-onset severe chorea, and microcephaly together with pontocerebellar hypoplasia. Family distribution supports autosomal recessive transmission. The present data support the PCH-2 phenotype as a distinct neurogenetic entity.

Adolescent↗
PubMed1994

[The significance of convulsion-like signs in the first 2 years of life].

OBJECTIVE: Assessment of the prevalence of convulsion-like symptoms in 1854 children of Dutch-speaking mothers of a population-based birth cohort. METHOD: At each child health clinic (CHC) visit mothers were asked whether they had noted any of the following signs: loss of consciousness, involuntary movements, eye rotation movements and apnoea, and if so, whether these appeared to be related to feeding. Registration was done by the CHC physician during eight consultations. RESULTS: Convulsion-like symptoms occurred in a quarter of the children: in 8% exclusively in relation to feeding, almost without exception in the first three months of life, in 19% also without relation to feeding, continuing until the second birthday. The latter children were more frequently admitted into hospital, even for non-neurological problems, than the former or than children without any such signs. They also have more disabilities at the age of two years. No connection with epilepsy in the family or with congenital anomalies could be demonstrated. CONCLUSION: Convulsion-like symptoms were observed in a quarter of children up to the age of two years. Special attention should be paid by the CHC team to children with signs not connected with feeding.

Child, Preschool↗
PubMed1993

[Neurological conversion disorders in older children].

BACKGROUND: Conversion symptoms with a neurological character are not unusual in children. Little is known about prognosis. This study aimed to determine the outcome in a group of children with conversion. PATIENTS AND METHODS: Over the period 1979-1989 35 children from 6 to 16 who met DSM-III-R criteria for conversion were selected from the case-records of the Child Neurology department of the University Hospital in Leiden. Case histories were analysed and 20 patients were interviewed at home and a standard questionnaire was used additionally. RESULTS: Conversion symptoms disappeared with time in 15 patients. In comparison with the control group, patients with conversion scored higher on nervousness. CONCLUSION: Conversion disorder runs a favourable course. The place of child psychiatric treatment should be analysed prospectively.

Adolescent↗
PubMed1992

Spread of herpes simplex virus to the cerebrospinal fluid and the meninges in experimental mouse encephalitis.

The development of the inflammatory response within the brain, meninges and cerebrospinal fluid (CSF) compartment has been studied for the first time simultaneously in experimental herpes simplex virus (HSV) encephalitis after inoculation via the cornea. Two major viral pathways were found from the eye to the brain: one through the trigeminal nerve to the brain stem and one through the nasolacrimal duct to the olfactory system. Viral antigen was found to be present in the CNS before there were clinical signs or cellular infiltration of brain tissue. Subsequently, the virus spread to all parts of the trigeminal brain stem complex. This phenomenon was accompanied by severe inflammation of the meninges covering the trigeminal root near its entry into the brain stem. The meninges near the entry of the olfactory fila also contained antigen. However, HSV-1 did not spread along meningeal rami of the trigeminal nerve and, consequently, is--at least in this experimental model--not a route to reach the inferior frontal and temporal lobes. The development of CSF changes followed the histopathological development of meningitis and encephalitis closely. HSV-DNA could be detected in the CSF from day 4 post inoculation (p.i.) and HSV-1-specific immunofluorescence in CSF cells was convincingly present on day 5 p.i.; on the same days (4 and 5 p.i.) inflammatory cells were found in apposition to infected cells in the brain. We postulate that HSV is carried to the CSF by infected leukocytes rather than a direct spread to the CSF by simple extension of the encephalitic process to the meningeal surface.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗