Determinants of aggression, and adaptive and maladaptive behaviour in older people with Down's syndrome with and without dementia

In a cross-sectional study of aggression, and adaptive and maladaptive behaviour in 128 subjects with Down's syndrome (DS), 29 of whom had dementia, the current authors found that the presence of dementia was not predictive of aggression or maladaptive behaviour. However, the level of adaptive behaviour was shown to be lower in subjects with dementia, and in those with lower levels of cognitive functioning, as measured on a rating instrument, the Test for Severe Impairment. Although the presence of aggressive behaviours is not higher in subjects with dementia and DS on cross-sectional review, it remains to be seen whether aggression will increase in individual cases with the onset or progression of dementia. The decline in adaptive behaviour shown in the present study confirms the findings of previous studies and indicates a direction for service development for persons with the dual diagnosis of dementia and DS.

Pseudoautosomal gene: possible association with bipolar males but not with schizophrenia

The phenomenon of anticipation has been demonstrated in several neuropsychiatric disorders and suggested for schizophrenia and bipolar affective disorder. Many conditions exhibiting anticipation have been shown to be caused by trinucleotide repeat (CAG/CTG) expansions. Some evidence suggests that these expansions also exist in individuals with schizophrenia and bipolar affective disorder. In this investigation, we analysed a polymorphic CAG repeat in the interleukin receptor gene (IL9R), mapped to the pseudoautosomal region Xq28 and Yq21 (a candidate region for schizophrenia and affective disorder). Two common alleles, differing by one repeat unit and two rare alleles were found in cases and controls. Allele frequencies of this repeat were investigated in Irish schizophrenic, bipolar disorder and ethnically matched control samples. We found no evidence of an increased frequency of larger CAG repeats in either the schizophrenic or bipolar affective disorder samples as a whole when compared to the controls. However, dividing the samples by sex demonstrated a significant association between bipolar affective disorder males and the larger allele (allele 2) (patients 54.8% vs controls 40.1%, chi2 = 6.7, P = 0.009). In addition, a decreased frequency of this allele has been observed in the female patients, but did not attain statistical significance (patients 37% vs controls 46%, chi2 = 2.1, P = 0.14). This provides preliminary evidence that this locus or a closely mapped DNA variant (in linkage disequilibrium with the CAG repeat) may be involved in the genetic susceptibility to bipolar affective disorder in males.

New xanthorin glycosides from a Dermocybe species

A mixture of the 8-O-beta-D-glucopyranoside of omega-hydroxyxanthorin 1-O-methyl ether (3) and the 8-O-beta-D-gentiobioside of xanthorin 1-O-methyl ether (4) was isolated from the water-soluble extractives of the Australian toadstool Dermocybe sp. WAT 22963. Compounds 3 and 4 were identified by characterization of their respective peracetyl derivatives 5 and 6.

No evidence to support the association of the potassium channel gene hSKCa3 CAG repeat with schizophrenia or bipolar disorder in the Irish population

Anticipation has attracted much interest and has been demonstrated in several neuropsychiatric disorders. For some disorders, this phenomenon has been found to correlate with the repeat number in large and unstable repeats (CAG/CTG). In addition, case control studies have suggested an increase in triplet repeat size in the psychoses. Recently, it was reported that the larger alleles (longer than 19 repeats) of the second potassium channel gene hSKCa3 are associated with schizophrenia in European and American samples. A similar trend, though not statistically significant, was also seen in bipolar disorder samples. This was further supported by an independent UK study.1 In this investigation, we have examined Irish familial schizophrenic patients, bipolar affective disorder patients and ethnically matched controls in an effort to replicate these findings. No significant differences between the patients and the control groups were observed. In addition, linkage analyses in the multiplex schizophrenic families showed no evidence for linkage or linkage disequilibrium. We concluded that the polymorphism of the second CAG repeat of the hSKCa3 gene is not a risk factor in schizophrenia or bipolar disorder, at least in the Irish population.

Schizophrenia and HLA: No association with PCR-SSOP typed classical loci in a large Irish familial sample

Susceptibility to autoimmunity is strongly influence by genes clustered in the MHC region, particularly class I and class II antigens. It has been proposed that there is an immune component in the aetiology of schizophrenia, and the distribution of human leukocyte antigens (HLA) in schizophrenic patients and controls has been investigated in numerous studies. Positive associations have been reported between schizophrenia and the HLA-A1, A2, A9, B5, Cw4, and DR8 and negative associations with HLA-DR4 and HLA-DQbeta*0602. Small sample size, variable diagnostic methodology, unreliable laboratory and statistical procedures, and possible mismatching of cases and controls may have contributed to a lack of consistency of results to date. Therefore, in this investigation we used a large and carefully diagnosed homogeneous Irish familial schizophrenic sample compared with ethnically matched controls. All alleles were determined using polymerase chain reaction amplification followed by short specific oligoprobes. We found no evidence of association with 80 HLA alleles (some previously not examined) from 4 genes. Our data therefore do not support the involvement of these classical HLA loci in the aetiology of schizophrenia at least in these Irish families. The remaining classical HLA loci (HLA-B and HLA-C) should be typed when reliable DNA-based methods become available.

HLA and schizophrenia: refutation of reported associations with A9 (A23/A24), DR4, and DQbeta1*0602

The aim of this study was to test previous hypotheses of association between schizophrenia and human leukocyte antigen (HLA) specificities A9 (A23/24), DR4, and allele DQbeta1*0602. Using sequence-specific oligonucleotide probes, 256 familial schizophrenic patients and 261 unrelated controls were genotyped at polymorphisms for HLA-A, DRbeta1, and DQbeta1 loci. No significant (p < 0.05) differences in the allele frequencies between schizophrenics and controls were found, either when examining the sample as a whole or when subdivided by clinical subtype or gender. The present data do not support association between these HLA specificities and schizophrenia, and our review of previous studies suggests that reported associations may well be false positive results.

Psychosocial implications of spinal cord injury

Spinal cord injury (SCI) is a devastating event that has not only physical but also social and psychological ramifications for both the injured person and the family. Within one brief moment, a person's world will be changed forever. Like a ripple on the water, one injured family member affects the entire family system. This article will identify the social and psychological forces that impact the injured person's quality of life along with that of his or her family and the interventions that can be instituted by acute care personnel.

Autosome search for schizophrenia susceptibility genes in multiply affected families

We have analysed 298 polymorphic markers in 13 families multiply affected with schizophrenia and related disorders using a combination of radiolabelled and fluorescent-based methodologies. The markers were distributed throughout the autosomes at an average spacing of 12.8 cM. The data were analysed with two-point linkage analysis (MLINK) and heterogeneity testing (HOMOG). Several genetic models were used ranging from near dominant to fully recessive. Multi-point analysis was performed for 27 regions demonstrating either contiguously positive lod scores in two or more consecutive markers, and in regions with two-point lod score(s) of 1.0 or above in a single marker. A proportion of the multi-point regions have been implicated in previous studies, thereby decreasing risk of false-positive results. However neither our two-point, nor multi-point scores reached the threshold value for significance of 3. 6. Nevertheless three regions were suggestive of linkage.

Outcomes of universal antenatal screening for haemoglobinopathies

OBJECTIVE

To evaluate universal antenatal screening for haemoglobinopathies.

SETTING

District general hospital serving a London borough with 45% ethnic minorities.

METHODS

Retrospective cohort study of 1444 women referred in 1688 pregnancies and 95 tertiary referrals during 101 pregnancies.

RESULTS

Unselected women at risk for sickle cell disease booked 2.7 weeks (95% confidence interval (CI) 0.14 to 5.1) later in gestation than those at risk for beta thalassaemia were less likely to attend counselling (83% v 93%, relative risk (RR) 0.89; 95% CI 0.85 to 0.94), their partners were less likely to be tested (77% v 95%, RR 0.81; 0.77 to 0.83), and they were less likely to accept prenatal diagnosis (22% v 90%, RR 0.37; 0.24 to 0.57). Over 99% of tertiary referrals attended counselling and had their partners tested. There were no significant differences in acceptance of prenatal diagnosis between those at risk of sickle cell disease and beta thalassaemia (55% v 67%). Unselected women at risk of sickle cell disease were significantly less likely to have their partner tested or to accept prenatal diagnosis than tertiary referrals, but not those at risk of beta thalassaemia. 80% of beta thalassaemia and 16% of SS births were prevented.

CONCLUSIONS

Uptake of prenatal diagnosis among unselected women at risk of beta thalassaemia is similar to that reported by tertiary centres. It is considerably lower for sickle cell disease but could increase considerably if screening occurred earlier in gestation. Acceptance of counselling is universally high, suggesting that informed choices are made, and indicating a need to measure these outcomes for cost effectiveness studies.

Meat production in developing countries

Developing countries have very diverse food consumption patterns and agricultural production systems. The proportion of meat in national diets varies from negligible in some countries in central Africa to 30-40% in some countries in Latin America and Mongolia. However, the demand for meat in developing countries is increasing rapidly (53%/year from 1982 to 1993), as the result of population growth and the trend for people to move to the cities. Growth rates in consumption are greatest in Asia, with China dominating the statistics, in view of the size of its population. Theoretically, livestock production can be increased to meet this demand, but the multiple roles of livestock in developing countries must be recognized if this is to be achieved in a sustainable manner. Resource-poor farmers who keep livestock may value more highly their contribution to livelihoods and to crop production, through provision of draught power and improvements in soil fertility through the recycling of manure, than the production of more meat. Recognition of the goals of the farmer and the wishes of the consumer regarding meat quality need to be reflected in the way in which opportunities for increasing meat production are identified and communicated to farmers. The impact of the global economy on cereal prices, for example, will also influence which interventions will be economically viable. Interpretation of information in an integral manner, using geographical information systems, mathematical models and/or simple spreadsheet models will be an important ingredient in turning scientific knowledge into increased meat production in developing countries.

Serotonin syndrome in a child after a single dose of fluvoxamine

Serotonin syndrome, a potentially fatal iatrogenic complication of psychopharmacologic therapy, is most commonly reported with combinations of serotonergic medications. Serotonin syndrome is characterized by alterations in cognition, behavior, autonomic, and central nervous system function as a result of increased postsynaptic serotonin receptor agonism. We present the first reported case of serotonin syndrome after a single dose of fluvoxamine in a pediatric patient after ingestion of a single supratherapeutic dose of fluvoxamine.

Insulin-like growth factor I, IGF binding protein 3, and IGFBP protease activity: relation to anthropometric indices in solid tumours or leukaemia

OBJECTIVES

To measure the serum concentrations of insulin-like growth factor I (IGF-I) and IGF binding protein 3 (IGFBP-3), and the level of IGFBP-3 protease activity in 38 children presenting with malignancies, and to assess their relation with auxological parameters and nutritional status.

METHODS

Height, weight, skinfold thickness, and mid-upper arm circumference (MUAC) were recorded using standard techniques. IGF-I and IGFBP-3 were measured using specific radioimmunoassays. Serum IGFBPs were also visualised on western ligand blot. IGFBP-3 protease activity was assessed by the extent of fragmentation of recombinant [125I]-IGFBP-3, compared with that induced by pregnancy serum. Anthropometric and radioimmunoassay data were expressed as standard deviation scores (SDS).

RESULTS

The median (range) IGF-I SDS was significantly reduced in all patients (-1.1 (-5.1 to 1.2)) and lower in children who were malnourished (-2.5 (-3.9 to 0.1)). IGFBP-3 SDS was within the normal range for 31 of 38 patients but IGFBP-3 protease activity was raised in all patients. Neither IGFBP-3 concentration nor protease activity was affected by nutritional status. IGF-I correlated with MUAC (r = 0.41) and subscapular skinfold thickness SDS (r = 0.38), but not with weight, height, weight for height, or triceps skinfold thickness.

CONCLUSIONS

IGF-I is low in children with malignancies, and even lower in those who are malnourished. IGFBP-3 concentrations were normal in most patients but interpretation is complicated by the presence of raised IGFBP-3 protease activity, which could lead to overestimating concentrations of intact peptide. IGF-I appears to relate to arm anthropometry as an index of nutritional status but not height, weight, or weight for height, as would be expected in normal children.

Mapping susceptibility loci in attention deficit hyperactivity disorder: preferential transmission of parental alleles at DAT1, DBH and DRD5 to affected children

Attention deficit hyperactivity disorder (ADHD) is a common disorder of childhood characterized by inattention, excessive motor activity, impulsivity, and distractibility. It is associated with serious disability in children, adolescents and adults. The etiology of the disorder is unknown, but it has a strong genetic component. Pharmacological and biochemical studies have suggested that dopaminergic and noradrenergic systems are involved. Using a sample of affected children and their parents we have found preferential transmission of alleles at polymorphisms at the dopamine transporter (DAT1), RR=1.2 (1.05-1.37), P=0.006, re-confirming and extending our previous findings for DAT1 (new sample one-tailed P=0.039); dopamine-beta-hydroxylase (DBH), RR=1.31 (1.09-1.56), P=0.0027; and the dopamine D5 receptor (DRD5), RR=1.67 (1.29-2.15), P=0.00005. Transmission of the 'associated' alleles at DAT1 and DBH is stronger in familial cases, RR(DAT1)=1.29 (1.04-1.59), RR(DBH)=1.49 (1.10-2.00), but for DRD5, transmission is stronger in non-familial cases, RR=1.59 (1.05-2.42). TDT analysis of complete trios supports the HHRR analysis, with P<0.05, for DAT1 P<0.005 and DBH and P<0.01 for DRD5. Attributable fractions for DAT1, DBH and DRD5 are calculated at 0.08, 0.12 and 0.20 respectively.

No linkage or linkage disequilibrium between brain-derived neurotrophic factor (BDNF) dinucleotide repeat polymorphism and schizophrenia in Irish families

There is increasing evidence that a neurodevelopmental process is accountable for at least a proportion of schizophrenic cases. Brain-derived neurotrophic factor (BDNF), a member of a group of proteins that includes neurotrophin-3/4/5 and nerve growth factor (NGF), is an attractive candidate gene. We have performed a case control association study using the BDNF dinucleotide repeat polymorphism in a sample of familial schizophrenic individuals and in healthy, ethnically matched control subjects. We also performed a linkage analysis on 265 multiplex families using the same marker. We found no differences in allele frequencies between the patient and control groups nor any evidence for transmission disequilibrium or linkage with the multiply affected families. We conclude that DNA variation at or near the BDNF gene is unlikely to contribute to the genetic predisposition to schizophrenia.

Linkage analysis between bipolar affective disorder and markers on chromosome X

Since 1969, several classical linkage studies suggested an X-chromosome locus for bipolar affective disorder. However, methods using highly polymorphic DNA markers have provided conflicting evidence for linkage, and an X-chromosomal locus for bipolar disorder remains controversial. More recently, Pekkarinen et al. (1995) found a maximum LOD score of 3.54 at the marker DXS994 in a large bipolar Finnish kindred. In the present study, we attempted to replicate this finding using 43 families multiply affected by bipolar affective disorder. These families were selected for the absence of male-to-male transmission of the disease, and were genotyped for two microsatellte markers, DXS1227 and DXS1062 (which is about 2 cM telomeric to DXS994). Linkage to this region was excluded either using a two-point lod score method with two plausible genetic models, or by a model-free lod score analysis which does not require specification of a particular mode of transmission. We conclude that there is no evidence of a common major gene for bipolar affective disorder at Xq25-q27 in our set of families.

Cognitive decline in Down syndrome: a validity/reliability study of the test for severe impairment

The utility of the Test for Severe Impairment was studied with 60 older persons who had Down syndrome. Construct validity, test-retest reliability, and interrater reliability were established for the full study group and for subgroups based on degree of mental retardation and dementia status. There was no difference in scores by gender. There were some interesting findings for the group with moderate mental retardation and dementia and the group with severe mental retardation without dementia that may signal specific applications and limitations of the test for use with individuals who have Down syndrome. The internal consistency of the instrument was satisfactory. Results suggest that this test is a useful performance-based task for persons with Down syndrome.

Motor activity effects in female Fischer 344 rats exposed to isopropanol for 90 days

In a previous subchronic neurotoxicity study, increases in motor activity were observed for female rats after 9 and 13 weeks of exposure to 5000 ppm of isopropanol vapor. The present study was conducted to evaluate the reproducibility of these effects and, if reproducible, to assess the potential for reversibility following cessation of exposure. Two groups, each containing 30 female Fischer 344 rats, were exposed to concentrations of zero (control) and 5000 ppm of isopropanol vapor for 6 h per day, 5 days per week. Fifteen of the animals in the control and 5000 ppm groups were exposed for 9 weeks (designated as the 9-week subgroup), while the other 15 animals in each group were exposed for 13 weeks (designated as the 13-week subgroup). Motor activity was assessed for both subgroups prior to exposure and following 4, 7 and 9 weeks of exposure. Motor activity was also measured for rats in the 13-week subgroup following 11 and 13 weeks of exposure. These motor activity measurements were made 18-20 h following the end of the last exposure for that week. In addition, to evaluate the reversibility of motor activity effects, measurements were made on three occasions during the week following the final exposure for rats in both the 9-week and 13-week subgroups and weekly thereafter for five additional weeks for rats in the 13-week subgroup. Increases in cumulative test session motor activity counts were observed following 4, 7 and 9 weeks of exposure for rats in the 9-week subgroup. Increases in cumulative test session motor activity counts were also observed following 4, 7, 9, 11 and 13 weeks of exposure for rats in the 13-week subgroup. Reversibility of this effect was observed for rats in the 9-week subgroup within 2 days following the last exposure. Reversibility was also noted for rats in the 13-week subgroup but not until Study Week 15 (2 weeks following the last exposure). Minor changes were observed in the shape of the motor activity habituation curves for isopropanol-exposed animals in the 9-week and 13-week subgroups at ca. 50% of the measurement intervals beginning at Study Week 4. While most of these statistical changes were observed in conjunction with increases in cumulative test session motor activity, some were observed following time points where recovery of the cumulative test session motor activity counts had occurred. No change in the shape of the motor activity habituation curve was observed at 42 days following the last exposure, indicating that complete recovery of motor activity effects had occurred. Thus, repeated exposure of female rats to 5000 ppm of isopropanol produced reversible increases in motor activity.

A transmission/disequilibrium study of the DRB1*04 gene locus on chromosome 6p21.3 with schizophrenia

Patients with schizophrenia rarely develop rheumatoid arthritis, an autoimmune disease that exhibits genetic association with the HLA DRB1*04 gene. We previously investigated the hypothesis that schizophrenia is negatively associated with DRB1*04, and found that only half the expected number of schizophrenic patients had this gene when compared with controls. We now report the results of DRB1*04 genotyping in pedigrees multiply affected with schizophrenia. Polymerase chain reaction amplification and sequence-specific oligonucleotide probes were used to determine the DRB1 genotypes of the 187 members of 23 pedigrees multiply affected with RDC schizophrenia. DQA1, DQB1 and DPB1 genotypes were similarly determined. We analysed data using the extended transmission/disequilibrium test and found a trend for the preferential non-transmission of DRB1*04 alleles from heterozygous parents to their schizophrenic offspring (16 of 23 alleles not transmitted, chi 2 = 3.5, p = 0.06). We found no evidence for a gene of major effect using GENEHUNTER for parametric and non-parametric linkage analysis. The results from this small sample need to be interpreted with caution, but they are in keeping with previous reports and suggest that HLA DRB1*04 alleles may be associated with a reduced risk of schizophrenia.

Do general practitioners know when living wills are legal?

BACKGROUND

There is growing public awareness of living wills or advance directives. Patients who wish to make advance directives may approach general practitioners (GPs) for advice. However, many GPs are unaware of the correct legal status of living wills.

METHODS

Questionnaires were sent to 270 GPs in London and Winchester, asking seven questions about the current legal status of living wills.

RESULTS

Of the 214 GPs (79%) who returned questionnaires, only 104 (49%) were aware that some types of advance directives could carry legal force. Many of the GPs who did know that living wills could be legally binding were unable correctly to answer further questions on the practicalities of the law; for example, 26% were wrong in believing that a lawyer had to draw up a living will, and 13% incorrectly believed that a doctor was legally required to give any treatment requested by a patient in a living will.

CONCLUSIONS

Half of the GPs surveyed were unaware that living wills currently have legal force and most of the rest were unaware of important details of the law. More attention needs to be given to the education of doctors in this area.