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J Kaiser

Publications and source records attributed to J Kaiser.

At least 127 records · Page 7Linked to original sources
PubMed1999

Effects of pubertal timing on EEG coherence and P3 latency.

Neurodevelopmental approaches to schizophrenia emphasise the role of late brain maturational events. Abnormalities here may account for both the putative cortico-cortical underconnectivity in schizophrenia and its typical onset in late adolescence. Saugstad hypothesised that maturational rate at puberty may lead to an extension of normal maturational processes such as synaptic pruning. In extreme late maturers pruning was thought to be prolonged, leading to reduced numbers of synapses and an increased risk for schizophrenia. Here we assessed the effects of pubertal timing extremes on EEG coherence and P3 latency as putative measures of brain development in N = 37 healthy adults. During photic stimulation late maturing males showed increased left-hemispheric coherence compared with male early maturers. This was in line with earlier findings (Kaiser, J., Gruzelier, J.H., 1996. Timing of puberty and EEG coherence during photic stimulation. Int. J. Psychophysiol. 21, 135-149). As expected, P3 latency was shorter in late compared with early maturers. However, this was true only for females, whereas there was no difference in males. These results are consistent with the notion of an exaggeration of normal maturational changes in slow maturation, whereby the underlying process appears to be different for males and females.

Adult↗
PubMed1999

Timing of puberty and syndromes of schizotypy: a replication.

The view of schizophrenia as a neurodevelopmental disorder involving an abnormality in the programmed elimination of excitatory synapses during puberty has been supported by recent neuroimaging studies suggesting disordered functional connectivity in schizophrenia. We investigated a model predicting dysfunctionally high or low synaptic density in extreme early or late maturers at puberty, respectively (Saugstad, L.F., 1989. Clin. Genet. 36, 156-167; Saugstad, L.F., 1994. Int. J. Psychophysiol. 18, 189-203). In an earlier study (Gruzelier, J.H., Kaiser, J., 1996. Schizophr. Res. 21, 183-194), we found increased psychosis proneness scores in both extremes of the pubertal timing spectrum in the normal population. Here we present a replication study where N = 100 healthy adults completed a retrospective pubertal timing scale and the 'Personality Syndrome Questionnaire' measuring schizotypy syndromes. The following relationships were replicated: (1) elevated scores on scales of the total Unreality syndrome and the Ideas of Reference subscale in both maturation extremes; and (2) a trend for a positive correlation between the Withdrawal scale and the composite maturation score in males. Cognitive Unreality and Suspiciousness were higher in early than late maturing females. Social Anxiety was elevated in female extreme maturers compared with average maturers, but the opposite was found for males, where average maturers had higher scores than early or late maturers. Active syndrome findings were confined to the male subsample with late maturing males showing higher scores on the Cognitive Failures and Odd Speech subscales than early maturers. As in the previous study, there was no relationship between a global psychosis proneness scale and maturational rate. These findings support a neurodevelopmental model of psychosis-proneness and show the importance of adopting a syndromal view.

Adult↗
PubMed1999

The Adolescence Scale (AS-ICSM): a tool for the retrospective assessment of puberty milestones.

Neurodevelopmental theories of psychosis, and schizophrenia in particular, have led to renewed interest in the relationships between brain maturation, adult personality and timing of puberty. Here we present a brief Adolescence Scale (AS-ICSM) for the retrospective assessment of puberty milestones. The recommended version comprises one item for females, three for males and one common to both. An original version of five items was administered to 318 young adults. We found good internal consistencies of Cronbach's alpha = 0.87 for females and 0.83 for males, having excluded an item assessing timing of growth spurt. These findings show that the AS-ICSM is a reliable and economic tool for research into the concomitants of early and late puberty.

Adolescent↗
PubMed1999

Evoked cardiac response components in cognitive processing: differential effects of amyotrophic lateral sclerosis.

We investigated the mechanism of two evoked cardiac response components associated with different aspects of information processing. Innocuous stimuli presented in an irrelevant condition elicit a simple cardiac deceleration termed ECR1. The same stimuli presented in a relevant condition (such as results from requesting subjects to silently count the stimuli) elicit a complex biphasic response with a large secondary acceleration in heart rate. This difference is attributed to the additional effect of cognitive task performance, resulting in an addition response component, ECR2. This may be realised by subtraction of the two responses. We investigated the mechanisms involved by comparing cardiac response profiles from a neurologically-impaired group with those from a control group amyotrophic lateral sclerosis (ALS) has been associated with a loss of synaptic connections in the frontal lobe. Twelve ALS clinically non-demented patients were age-matched with twelve neurological patients without pathological changes in the brain. Cardiac response profiles for ECR1 and ECR2 were examined as a function of group. ECR1 did not differ between the groups, but ECR2 was significantly impaired in the ALS patients. The results are discussed in terms of different brain regions associated with these two cardiac response components. ECR1 may be associated with automatic preattentive stimulus registration involving, in the case of auditory stimuli, the auditory analyser and associated pathways, while ECR2 appears to be a correlate of controlled executive processing, involving the frontal cortex.

Acoustic Stimulation↗
PubMed1999

Helicobacter pylori increases the risk of peptic ulcer bleeding: a case-control study.

AIM: Aim of the present case-control study was to establish whether Helicobacter pylori increases the risk of ulcer bleeding. PATIENTS AND METHODS: All patients presenting with upper gastrointestinal bleeding between November 1994 and November 1995 were prospectively investigated and compared with hospital controls matched for age, sex, and race. We evaluated the frequency of Helicobacter pylori infection, intake of aspirin or non-steroidal anti-inflammatory drugs, use of alcohol, and smoking habits in patients and controls. RESULTS: Included in the study were 128 patients. In 72 patients, the source of bleeding was a peptic ulcer (duodenal ulcer: n = 33; gastric ulcer: n = 39). Ulcer patients were more frequently infected by Helicobacter pylori than controls (72% vs 42%; p < 0.001) while the incidence of infection was similar in patients with non-ulcer bleeding and controls (52% vs 46%; p = 0.59). Conditional multiple logistic regression analysis showed that Helicobacter pylori infection (odds ratio, 3.3 [Confidence interval, 1.5 to 7.0]; p = 0.002) and regular use of alcohol (odds ratio, 3.1 [Confidence interval, 1.0 to 9.0]; p = 0.041) increased the risk of peptic ulcer bleeding while previous intake of aspirin (> 100 mg) or non-steroidal anti-inflammatory drugs independently increased the risk of bleeding only in the case of gastric ulcer (odds ratio, 8.1 [Confidence interval 1.2 to 56.6]; p = 0.034). CONCLUSIONS: Helicobacter pylori infection increases the risk of peptic ulcer bleeding. Our results suggest that Helicobacter pylori and non-steroidal anti-inflammatory drugs are independent risk factors for peptic ulcer bleeding.

Adult↗
PubMed1998

Blue rubber bleb nevus syndrome.

Blue rubber bleb nevus syndrome is a rare autosomal dominant disorder of multiple venous malformations of the skin and gastrointestinal tract. The fragility of the gastrointestinal lesions may lead to significant occult blood loss and subsequent anemia.

Diagnosis, Differential↗