Infantile glaucoma in Down's syndrome (trisomy 21)

We examined five patients with Down's syndrome and bilateral infantile glaucoma. In the first few months of life four patients had large cloudy corneas, breaks in Descemet's membrane, increased intraocular pressure, photophobia, and tearing. In one patient the diagnosis was delayed until 3 1/2 years of age because of concomitant nasolacrimal duct obstruction. Two patients developed cataracts and retinal detachment and have undergone multiple surgical procedures. The clinical course in these two older patients suggests that coexistence of congenital glaucoma, severe myopia, and cataracts in patients with trisomy 21 strongly predisposes for the development of retinal detachment and poor visual outcome.     

Serologic evidence for human ehrlichiosis in Africa

Human ehrlichiosis is a recently recognized rickettsial disease. It is caused byEhrlichia chaffeensis, an intraleucocytic Gram-negative, obligate intracellular bacterium, grouped within the genusEhrlichiae. Most human cases of ehrlichiosis have been diagnosed in the USA. Two cases have been reported outside of the USA, one in Europe and one in Africa. From 1 January to 30 June 1992, 765 sera from blood donors or other asymptomatic subjects in 8 African countries, including Ivory Coast, Burkina Faso, Mali, Central African Republic, Angola, Zimbabwe, Mozambique and Commores Islands, were tested by indirect immunofluorescence for the presence ofE. chaffeensis antibodies. Positive sera were confirmed by Western immunoblotting. Only two of 765 sera tested were positive. One serum obtained from Burkina Faso had an IgG titer of 1:200 and one from Mozambique had an IgG titer of 1:80. Human ehrlichiosis seems to occur infrequently in Africa, although many more sera from additional African countries need to be evaluated.     

Continuous intravenous propofol with nitrous oxide for ocular surgery. A comparison with etomidate, alfentanil, nitrous oxide and isoflurane.

Propofol, administered intravenously for induction and as a continuous maintenance anaesthetic with nitrous oxide, was compared, in a group of elderly patients scheduled for ophthalmic surgery, with an anaesthetic technique (etomidate, alfentanil, nitrous oxide and isoflurane) specifically chosen to be haemodynamically stable and evanescent in action. Both techniques resulted in similar effects on blood pressure after induction, intubation and surgical incision, but propofol did not prevent increases in heart rate as effectively at these times. Furthermore, during maintenance anaesthesia, cardiovascular stability and anaesthetic depth were more easily achieved in the group where etomidate, alfentanil and isoflurane were used. Propofol decreased intra-ocular pressure after intubation, while in both groups recovery was rapid with no significant complications. A subgroup of patients receiving alpha-methyldopa had significantly longer post-anaesthetic recovery times.     

Cataract, hearing loss and hypercholesterolemia

A new syndrome of congenital cataract, hearing loss, hypercholesterolemia, spasticity of the lower extremities, and perhaps mental retardation, is described. Manifestation in two brothers with no other affected family members suggests an autosomal recessive pattern of inheritance. A discussion of the differential diagnosis of oculo-auditory syndromes is presented.     

The hemodynamics of oddball processing during single-tone and two-tone target detection tasks

Event-related potential (ERP) studies have shown that the neural systems engaged during performance of oddball tasks are sensitive to contextual manipulations, such as the number of stimulus classes. Some ERP components (i.e., N1) are modulated by the number of stimulus types, while others (i.e., P3) are not greatly affected. However, little is known about how these contextual manipulations affect the hemodynamics underlying oddball processing. The purpose of this study was to examine the hemodynamic correlates of target stimulus processing in single-tone (targets alone) and two-tone (targets and standard tones) auditory oddball tasks. The primary hypothesis was that processing of salient stimuli in both contextual conditions would engage the same spatially distributed cortical and subcortical networks observed in previous oddball fMRI studies. Results were consistent with this hypothesis and suggest that the brain engages many potentially useful brain regions during salient stimulus processing despite the low probability that said regions are necessary for task performance, which likely reflects a form of “adaptive reflexive processing”. Results were also consistent with ERP data that shows that the N1 is larger for single-tone tasks by showing greater amplitude of hemodynamic response for single-tone targets, relative to two-tone targets, in bilateral temporal cortex and bilateral inferior lateral frontal cortex. The results are discussed as they relate to the understanding of neurocognitive function pertaining to contextual manipulations in general, and orienting processes in particular.     

Comparison of two ELISAs for the determination of Hsp70 in serum

We have compared a previously developed in-house Sandwich-ELISA with a commercial kit for the determination of heat shock protein (Hsp) 70 in serum. Samples from 64 participants were tested and there was a significant correlation between results obtained using the two assays (r = 0.807, p < 0.0001). Additionally, when ranking samples on a categorical scale, the agreement was good (72%). In the commercial test system Hsp70 was detectable in 42 (66%) of the sera, compared with 61 (95%) in the in-house ELISA method. The three samples with undetectable levels of Hsp70 in the in-house ELISA were among the 22 samples with undetectable levels of Hsp70 in the commercial ELISA kit. The apparent serum concentrations detected were different in the two systems. This dissimilarity can be ascribed to differences in the matrix used. We conclude that the in-house ELISA is more economical and performs well when measuring physiologically high, as well as low, concentrations of Hsp70.     

RSV-induced bronchiolitis but not upper respiratory tract infection is accompanied by an increased nasal IL-18 response

The aim of this study was to investigate potential differences in the local nasal immune response between bronchiolitis and upper respiratory tract infection induced by respiratory syncytial virus (RSV). Nasal brush samples were obtained from 14 infants with RSV bronchiolitis and from 8 infants with RSV upper respiratory tract infection. The samples were taken during infection (acute phase) and 2-4 weeks later (convalescent phase). Cytospin preparations were stained immunohistochemically for T cells, macrophages, and eosinophils. Staining also took place for intercellular adhesion molecule-1 (ICAM-1), T-helper 1 (Th1)-like (interleukin-12 [IL-12], interferon-gamma [IFN-gamma]), Th2-like (IL-4, IL-10), and proinflammatory cytokines (IL-6, IL-8, IL-18). During both RSV-induced bronchiolitis and upper respiratory tract infection, cellular inflammation was observed. This was characterised by an increase in the numbers of nasal macrophages, which tended to be higher in bronchiolitis than in upper respiratory tract infection. Numbers of T lymphocytes and ICAM-1 positive cells increased during both bronchiolitis and upper respiratory tract infection. There were no differences between numbers in the groups. Interestingly, a distinct nasal proinflammatory cytokine response was observed in RSV-induced bronchiolitis. This is characterised by an increase in the number of IL-18 positive cells. This increase is specific for bronchiolitis, as a similar increase could not be detected in RSV-induced upper respiratory tract infection. Numbers of IL-6 and IL-12 positive cells were higher in both bronchiolitis and upper respiratory tract infection, and there were no differences between the groups. By contrast, the number of IL-8, IFN-gamma, IL-4, and IL-10-positive cells remained constant. In conclusion, clear differences were found in nasal immune responses of children with RSV-induced upper respiratory tract infection or bronchiolitis. The induction of a strong IL-18 response was typical for bronchiolitis, as this could not be observed in RSV-induced upper respiratory tract infection, and could explain the eosinophilia that is observed frequently during bronchiolitis.