Are There Subgroups within the Autistic Spectrum? A Cluster Analysis of a Group of Children with Autistic Spectrum Disorders

Comprehensive data on the developmental history and current behaviours of a large sample of high-functioning individuals with diagnoses of autism, Asperger's syndrome, or other related disorder were collected via parent interviews. This provided the basis for a taxonomic analysis to search for subgroups. Most participants also completed theory of mind tasks. Three clusters or subgroups were obtained; these differed on theory of mind performance and on verbal abilities. Although subgroups were identified which bore some relationship to clinical differentiation of autistic, Asperger syndrome, and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS) cases, the nature of the differences between them appeared strongly related to ability variables. Examination of the kinds of behaviours that differentiated the groups suggested that a spectrum of autistic disorders on which children differ primarily in term of degrees of social and cognitive impairments could explain the findings.     

Tenofovir, adefovir, and zidovudine susceptibilities of primary human immunodeficiency virus type 1 isolates with non-B subtypes or nucleoside resistance

New antiretroviral drugs with activity against strains of human immunodeficiency virus type 1 (HIV-1) with non-B subtypes and with resistance to current antiretroviral drugs are needed. The activity of two nucleotide analogs, tenofovir and adefovir (PMPA and PMEA, respectively), against non-B subtypes and nucleoside-resistant primary HIV-1 isolates was assessed. Tenofovir and adefovir were fully active against a panel of subtypes A, C, D, E, F, G, and group O primary HIV-1 isolates as compared with their respective activity against subtype B isolates. Moreover, the susceptibility of a panel of 10 primary HIV-1 isolates with >10-fold mean resistance to zidovudine, lamivudine, and abacavir was within 2.2-fold of wild-type tenofovir susceptibility for each isolate. An oral prodrug of tenofovir, tenofovir disoproxil fumarate (DF), is currently in phase III clinical trials for the treatment of HIV-1 infection. These in vitro susceptibility results suggest that tenofovir DF may be active in vivo against HIV-1 with nucleoside resistance as well as against HIV-1 with non-B subtypes.     

Role of nocturnal hypoxaemia in the genesis of systemic hypertension

Two groups of patients with nocturnal arterial oxygen desaturation were compared. The degree of nocturnal oxygen desaturation, as reflected by the percentage of total sleep time spent with an oxygen saturation less than 90 and 80%, was similar in patients with the obstructive sleep apnoea syndrome (OSAS) and in those with nocturnal hypoventilation (NH) secondary to restrictive chest wall disease. Systemic hypertension was present in 16 of the 24 OSAS patients but in only 6 of the 24 with NH (p less than 0.005). Multiple regression analysis demonstrated that this difference remained significant even after adjustment for age, sex, weight and history of smoking. It is likely that factors other than nocturnal hypoxaemia are important in the aetiology of systemic hypertension in patients with sleep-related breathing disorders.     

Familial multiple bilateral pneumothorax associated with Marfan syndrome

Three members of one family, a father and two sons, inflicted with Marfan syndrome, suffered multiple bilateral episodes of spontaneous pneumothorax that required repeated drainage procedures. The youngest patient also had an episode of unilateral expansion pulmonary edema; he underwent sequential pleural abrasions. Familial pneumothorax is very uncommon, and its association with Marfan syndrome is an exception.