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S Schuck

Publications and source records attributed to S Schuck.

12 recordsLinked to original sources
PubMed2003

High prevalence of rare dopamine receptor D4 alleles in children diagnosed with attention-deficit hyperactivity disorder.

Associations have been reported of the 7-repeat (7R) allele of the human dopamine receptor D4 (DRD4) gene with both the personality trait of novelty seeking and attention-deficit/hyperactivity disorder (ADHD). The increased prevalence of the 7R allele in ADHD probands is consistent with the common variant-common disorder hypothesis, which proposes that the high frequency of many complex genetic disorders is related to common DNA variants. Recently, based on the unusual DNA sequence organization and strong linkage disequilibrium surrounding the DRD4 7R allele, we proposed that this allele originated as a rare mutational event, which nevertheless increased to high prevalence in human populations by positive selection. We have now determined, by DNA resequencing of 250 DRD4 alleles obtained from 132 ADHD probands, that most ADHD 7R alleles are of the conserved haplotype found in our previous 600 allele worldwide DNA sample. Interestingly, however, half of the 24 haplotypes uncovered in ADHD probands were novel (not one of the 56 haplotypes found in our prior population studies). Over 10 percent of the ADHD probands had these novel haplotypes, most of which were 7R allele derived. The probability that this high incidence of novel alleles occurred by chance in our ADHD sample is much less than 0.0001. These results suggest that allelic heterogeneity at the DRD4 locus may also contribute to the observed association with ADHD.

Amino Acid Sequence↗
PubMed2001

Serum response factor is required for immediate-early gene activation yet is dispensable for proliferation of embryonic stem cells.

Addition of serum to mitogen-starved cells activates the cellular immediate-early gene (IEG) response. Serum response factor (SRF) contributes to such mitogen-stimulated transcriptional induction of many IEGs during the G0-G1 cell cycle transition. SRF is also believed to be essential for cell cycle progression, as impairment of SRF activity by specific antisera or antisense RNA has previously been shown to block mammalian cell proliferation. In contrast, Srf(-/-) mouse embryos grow and develop up to E6.0. Using the embryonic stem (ES) cell system, we demonstrate here that wild-type ES cells do not undergo complete cell cycle arrest upon serum withdrawal but that they can mount an efficient IEG response. This IEG response, however, is severely impaired in Srf(-/-) ES cells, providing the first genetic proof that IEG activation is dependent upon SRF. Also, Srf(-/-) ES cells display altered cellular morphology, reduced cortical actin expression, and an impaired plating efficiency on gelatin. Yet, despite these defects, the proliferation rates of Srf(-/-) ES cells are not substantially altered, demonstrating that SRF function is not required for ES cell cycle progression.

Animals↗
PubMed2000

Attention deficit/hyperactivity disorder children with a 7-repeat allele of the dopamine receptor D4 gene have extreme behavior but normal performance on critical neuropsychological tests of attention.

An association of the dopamine receptor D4 (DRD4) gene located on chromosome 11p15.5 and attention deficit/hyperactivity disorder (ADHD) has been demonstrated and replicated by multiple investigators. A specific allele [the 7-repeat of a 48-bp variable number of tandem repeats (VNTR) in exon 3] has been proposed as an etiological factor in attentional deficits manifested in some children diagnosed with this disorder. In the current study, we evaluated ADHD subgroups defined by the presence or absence of the 7-repeat allele of the DRD4 gene, using neuropsychological tests with reaction time measures designed to probe attentional networks with neuroanatomical foci in D4-rich brain regions. Despite the same severity of symptoms on parent and teacher ratings for the ADHD subgroups, the average reaction times of the 7-present subgroup showed normal speed and variability of response whereas the average reaction times of the 7-absent subgroup showed the expected abnormalities (slow and variable responses). This was opposite the primary prediction of the study. The 7-present subgroup seemed to be free of some of the neuropsychological abnormalities thought to characterize ADHD.

Alleles↗
PubMed2000

Double blind study of tiapride versus haloperidol and placebo in agitation and aggressiveness in elderly patients with cognitive impairment.

OBJECTIVE: The aim of the present study was to compare the efficacy and safety of tiapride versus haloperidol and placebo in the treatment of agitation and aggressiveness in elderly patients with mild or moderate mental impairment. METHOD: This international, multicentre, randomized, double blind, three parallel groups study compared efficacy and safety of a 21 -day regimen of tiapride 100-300 mg/day versus haloperidol 2-6 mg/day and placebo in 306 elderly patients with mild or moderate dementia according to DSM III R and behavioural troubles with the Multidimensional Observation Scale for the Elderly Subjects (MOSES) irritability/aggressiveness subscore ranging from 16 to 30. RESULTS: The percentage of responders (defined as patients with at least a 25% MOSES irritability/aggressiveness subscore decrease between the inclusion and the end of the treatment) was significantly greater in the tiapride (63%, P=0.04) and haloperidol (69%, P=0.004) groups than in the placebo group (49%), with no significant difference between the active drugs. Similar results were observed for the mean MOSES irritability/aggressiveness subscores on D7, D21 and at D(end) which were significantly smaller in the tiapride and haloperidol groups than in the placebo group. The decrease between D0 and D(end) was significantly greater in the tiapride (6.57, P=0.009) and haloperidol groups (6.75, P=0.005) than in the placebo group (4.71). The global improvement CGI was significantly better in the tiapride and haloperidol groups than in the placebo group (P=0.03 and P=0.02). No significant difference was observed between the two active drugs or among the three treatment groups for the Folstein's Mini Mental Status scale (MMS) total score, and there was no notable change during treatment. The number of patients with adverse events, assessed on the Udvalg Kliniske Undersogelser scale (UKU), and the number of UKU symptoms were smaller in the tiapride group (62 patients, 61%, 212 events) than in the haloperidol group (77 patients, 76%, 305 events) and identical to that observed in the placebo group (69 patients, 67%, 234 events). Of interest, the number of patients with at least one extrapyramidal symptom was significantly lower (P=0.003) in the tiapride group (16 patients, 16%) than in the haloperidol group (34 patients, 34%) and similar to that of the placebo group (18 patients, 17%); the difference observed between the haloperidol and placebo groups was significant (P=0.008). CONCLUSION: Tiapride is not different from haloperidol in the treatment of agitation and aggressiveness in elderly patients and better tolerated, in particular with significantly fewer extrapyramidal symptoms.

Aged↗
PubMed2000

Dopamine genes and ADHD.

Family, twin, and adoption studies have documented a strong genetic basis for ADHD/HKD, but these studies do not identify specific genes linked to the disorder. Molecular genetic studies can identify allelic variations of specific genes that are functionally associated with ADHD/HKD, and dopamine genes have been the initial candidates based on the site of action of the stimulants drugs, which for a half century have provided the primary pharmacological treatment for ADHD/HKD. Two candidate dopamine genes have been investigated and reported to be associated with ADHD/HKD: the dopamine transporter (DAT1) gene [Cook et al., American Journal of Human Genetics 1995;56:993-998, Gill et al., Molecular Psychiatry 1997;2:311-313] and the dopamine receptor D4 (DRD4) gene [LaHoste et al., Molecular Psychiatry 1996;1:121-124: Smalley et al., 1998;3:427-430; Swanson et al., Molecular Psychiatry 1998;3:38-41]. Speculative hypotheses [Swanson and Castellanos, NIH Consensus Development Conference: Diagnosis and Treatment of Attention Deficit Hyperactivity Disorder, November 1998. p. 37-42] have suggested that specific alleles of these dopamine genes may alter dopamine transmission in the neural networks implicated in ADHD/HKD (e.g. that the 10-repeat allele of the DAT1 gene may be associated with hyperactive re-uptake of dopamine or that the 7-repeat allele of the DRD4 gene may be associated with a subsensitive postsynaptic receptor). These and other variants of the dopamine hypothesis of ADHD will be discussed.

Alleles↗
PubMed2000

Linkage of the dopamine D4 receptor gene and attention-deficit/hyperactivity disorder.

OBJECTIVE: There is considerable evidence supporting a genetic component in the etiology of attention-deficit/hyperactivity disorder (ADHD). Because stimulant medications act primarily on the dopaminergic system, dopamine system genes are prime candidates for genetic susceptibility factors for ADHD. Previous studies by several groups have observed a significant association of ADHD and an allele with 7 copies of the 48 base pair repeat in the third exon of the dopamine D4 receptor. METHOD: The authors sought to replicate these previous findings by collecting an independent sample of families from Toronto, Ontario, Canada, and confirming this finding in an expanded sample of ADHD families collected from Irvine, California. Using the transmission disequilibrium test (TDT), the authors tested for biased transmission of the 7-repeat allele at the exon III polymorphism of the dopamine D4 receptor locus in these samples of ADHD subjects. RESULTS: Biased transmission of the 7-repeat allele from parents to ADHD probands and their affected siblings was observed in the 2 new samples of families collected in Toronto and Irvine (TDT chi2 = 2.711, 1 df, one-sided p value = .050) and for these samples combined with the 52 families previously reported from Irvine (TDT chi2 = 6.426, 1 df, one-sided p value = .006). CONCLUSIONS: The results of this study further support the possibility of a role of the dopamine D4 receptor locus in ADHD.

Adolescent↗
PubMed1998

[Drugs on the Internet. Hazards of public health].

The development of internet and more generally of telematics has given rise to many practical consequences in medicine. Whatever the context (communication, medias, teaching, imaging or data transmissions), Internet appears as a familiar tool in many medical fields. However some drift with harmful consequences for public health is emerging. This is particularly true for drugs sales via Internet. The absence of any control by health authorities over Internet drug sales raises acute legal problems for jurists, pharmacists, pharmacologists and public health physicians. A debate on the main difficulties is urgently needed.

Drug Therapy↗
PubMed1998

Effect of bromazepam versus placebo on inhibition and waiting capacity in young women with traits of anxiety.

The effect of 3 dosages of bromazepam administered as single oral doses (1.5, 3 and 6 mg) on anxious inhibition phenomena was studied in a population of 16 young women (18-30 years) with anxiety-traits, selected on the criteria of Cattell's anxiety scale supported by two personality inventory (Eysenck's, MMPI). A double-blind, placebo study design was chosen. The main assessment criteria were based on the go/no-go test (Logan's procedure), slow response rate (SRR) and a task of forced or unforced decision (use of the CFF). Attentional processes and declarative memory were analyzed as secondary criteria. None of the three dosages modified inhibition or acting-out. Sustained attention was reduced with 1.5 mg and 6 mg, as was memory performance with 3 and 6 mg, 3.5 h after drug administration. In contradistinction with studies carried out in healthy volunteers or with other benzodiazepine compounds, bromazepam at single low dosages does not modify inhibition capacity in these subjects with traits of anxiety, in this particular procedure.

Administration, Oral↗
PubMed1977

Acinetobacter septicaemia following prolonged intravenous therapy.

A 76-year-old man developed septicaemia during the infusion of stable plasma protein solution (SPPS) which was subsequently shown to be contaminated with Acinetobacter anitratus. Septicaemia persisted for four days despite change of the intravenous cannula and administration of an appropriate antibiotic. Clinical improvement occurred only when the entire intravenous line, (infusion bottle, airway needle, giving set and intravenous cannula), all of which grew Acinetobacter, was replaced. Contamination of the SPPS probably occurred in the ward via a contaminated giving set and airway needle, which had been in use for one week. This case illustrates the importance of following accepted guidelines for infection control in intravenous therapy.

Acinetobacter↗
PubMedDate not supplied

[Validation of the Short Cognitive Battery (B2C). Value in screening for Alzheimer's disease and depressive disorders in psychiatric practice].

UNLABELLED: Alzheimer's disease (AD) is a major healthcare challenge due to the increasing longevity of the population. Clinically prominent neuropsychological and neurological impairments, together with behavioral disorders characterize Alzheimer's disease (AD). In the past, behavioural and emotional disturbances received less attention than cognitive symptoms in studies of dementia. The association between cognitive and behavioural symptoms is complicated by the fact that such association could also occur with different patterns during depressive episode without dementia. Because Alzheimer's disease (AD) tends to be under diagnosed, there is an increasing need for accurate neuropsychological screening tools that are easy to administer by psychiatrists. The aim of the present study was to validate, in French, a sensitive and specific screening battery (B2C) designed to improve the discrimination between patients with AD, patients with depression, and healthy elderly subjects. POPULATION AND METHOD: The B2C was administered to 123 ambulatory subjects (mean age 76.4 2.3 years): divided in three groups of subjects. AD subjects were included (n=49) with a Mini-Mental Status Examination (MMSE) score of between 18 and 26, and a confirmed diagnosis (DSM IV) of mild to moderate AD. Subjects were not included if they were receiving treatment with an acetylcholinesterase inhibitor. The depressive group comprised elderly subjects (n=27) with at least two DSM IV criteria for a major depressive episode including the depressive mood criterion and a score of more than 17 on the Montgomery-Asberg Depression Rating Scale (MADRS). The healthy control group (n=47) comprised age-matched subjects with no neurological or psychiatric pathology. The B2C consists of four individual tasks derived from classical neuropsychological tests. Tasks were presented in the following order: temporal orientation test (knowledge of month, date, year, day of the week and time of day), 5 word test (task is originally derived from the Enhanced Cued Recall test), clock drawing test (In this widely used test, the subject had to draw a clock with all the numbers and then draw the clock hands at twenty minutes to four), and the semantic verbal fluency test (the subject was asked to generate as many words as possible from a given category in a fixed time period of 60 seconds). During the pre-study investigator meeting, the test procedure was adapted to ensure uniformity of practice in all centres. The B2C was administered one week to one month after the study inclusion date by a psychologist blinded to the patient groups and who had not participated in the subject's inclusion. Multivariate analysis was performed using a forced model of all four tests. Due to the nature of the dependent variable (AD vs controls and depressive vs control), the chosen discrimination model was a binary logistical regression model. Explanatory variables were limited to the variables of the test battery, and the dependent variable was the subject's status (AD, depressive or control). RESULTS: The mean results for each test are presented in Table II. The time taken to perform the tests was significantly higher (p=0.0001) for the AD group (11.2 minutes) when compared with both the control (7.6 minutes) and depressive group (8.2 minutes). In each of the four subtests, the AD subjects were significantly more impaired than the two other groups. Multivariate analysis was performed using a forced model of all four tests which provided correct classification of a high percentage of subjects (88.5%). The analysis followed a normal distribution and demonstrated that the AD patients were significantly impaired in all four tests of the B2C compared with controls. Depressive, elderly subjects were only impaired in verbal fluency. Multivariate analysis showed that, compared with controls, patients with mild AD were significantly impaired for all four tests. Response operating characteristics (ROC) analysis of the B2C showed: 93.8% sensitivity and 85% specificity for discriminating AD from control patients (table III), and 63% sensitivity and 96% specificity for discriminating AD from depressive patients (table IV). DISCUSSION: The main objective of this study was to demonstrate that the Short Cognitive Evaluation Battery developed in the French language is able to discriminate between patients suffering from AD and healthy elderly subjects. The results clearly demonstrate that AD patients were significantly impaired in all four tests of the B2C compared with the control group. The present study also supports the use of the screening battery for discriminating between AD and depressive subjects. The SCEB was less discriminatory for AD versus depressive patients than for AD versus controls. This could be due to the limited size of the depressive group. The verbal fluency test was the most sensitive for discriminating between AD and depression but this was at the expense of specificity. Other brief screening tests have already been developed in English speaking countries, In French language, the B2C appears to be a highly sensitive and specific tool for discriminating between patients with mild AD and healthy elderly individuals. Furthermore, in combination with clinical evaluation, the B2C could improve the specificity of the difficult discrimination between mild AD and depression. The next step of the validation process will include concurrent validity study and inclusion of a higher number of subjects with depressive symptoms.

Aged↗