Autosomal dominant cone-rod dystrophy due to a missense mutation (R838C) in the guanylate cyclase 2D gene (GUCY2D) with preserved rod function in one branch of the family

We present the clinical and molecular genetic features of a large multi-generation Norwegian family with dominant cone-rod dystrophy. Ophthalmological evaluation including electroretinography showed cone dysfunction in younger patients, with rod dysfunction becoming apparent at more advanced stages of the disease. In one branch of the family, cone degeneration remained the only manifestation despite advancing age. Linkage analysis mapped the disease gene in this family to 17p12-p13, a chromosome region previously linked to cone-rod dystrophy in a Swedish family (CORD5). A maximum LOD score of 3.25 (straight theta = 0.00) for marker D17S1844 was obtained. Mutation analysis of the guanylate cyclase 2D gene (GUCY2D, MIM 600179, previously called RETGC1), located at 17p12-p13, showed a missense mutation (R838C) in exon 13, that co-segregated with the eye disease in the family. Our suspicion of the possibility of an interrelationship between the Swedish CORD5 family and the present family, both originating from Northern Scandinavia, initiated the linkage analysis in the Norwegian family. The R838C missense mutation was not, however, detected in the Swedish patients, strongly suggesting no relationship between these two families. The long-term ophthalmological evaluation in this large four-generation family, combined with the identification of the disease-causing mutation, provide critical information for refining the classification, prognosis, and genetic counselling of patients with cone-rod dystrophies.     

Human retinal pigment epithelial cells inhibit proliferation and IL2R expression of activated T cells

The purpose of this study was to characterize the effects of human retinal pigment epithelial (RPE) cells on activated T cells. Activated T cells were cocultured with adult and foetal human RPE cells whereafter apoptosis and proliferation were determined by flow cytometry and (3)H-Thymidine incorporation assay, respectively. T cells and RPE cells were cultured directly together or in a transwell system for determination of the effect of cell contact. The importance of cell surface molecules was examined by application of a panel of blocking antibodies (CD2, CD18, CD40, CD40L, CD54, CD58) in addition to use of TCR negative T cell lines. The expression of IL2R-alpha -beta and -gamma chains of activated T cells was analysed by flow cytometry after incubation of T cells alone or with RPE cells. Human RPE cells were found to inhibit the proliferation of activated T cells by a cell contact-dependent mechanism. The RPE cells inhibitory abilities were not affected by blocking of any of the tested surface molecules. The inhibition of the T cells' proliferation correlates with a decreased expression of IL2R-beta and -gamma chains. The T cells regain their ability to proliferate and increase their IL2R-beta and -gamma chain expression within 24 hr after removal from the coculture. It is concluded that the cultured human adult and foetal RPE cells inhibit the proliferation of activated T cells by a process that does not involve apoptosis. It depends on cell contact but the involved surface molecules were not revealed. The proliferation inhibition correlates with a modulation of the T cells' expression of IL2R, and is reversible.     

Population-based study of acute respiratory infections in children,Greenland

Acute respiratory infections (ARI) are frequent in Inuit children, in terms of incidence and severity. A cohort of 294 children <2 years of age was formed in Sisimiut, a community on the west coast of Greenland, and followed from 1996 to 1998. Data on ARI were collected during weekly visits at home and child-care centers; visits to the community health center were also recorded. The cohort had respiratory symptoms on 41.6% and fever on 4.9% of surveyed days. The incidence of upper and lower respiratory tract infections was 1.6 episodes and 0.9 episodes per 100 days at risk, respectively. Up to 65% of the episodes of ARI caused activity restriction; 40% led to contact with the health center. Compared with studies from other parts of the world, the incidence of ARI appears to be high in Inuit children.     

Pharmacokinetics of rectal paracetamol after repeated dosing in children

Twenty-three children(aged between 9 weeks and 11 yr) were givenparacetamol suppositories 25 mgkg^–1 every 6 h (maximum5 days) after major surgery andserum and saliva concentrationswere measured. There was a good correlation(r=0.91, P<0.05)between saliva andserum concentrations. A one-compartment linearmodel withfirst-order elimination and absorption and lag-timewas fitted tothe data (ADAPT II). At steady state, the mean(SD)concentration was 15.2 (6.8) mg litre^–1. Mean (SD)time to reach 90% of the steady state concentrationwas 11.4(8.6) h. Body weight, age and body surface area were wellcorrelated(P<0.05) with clearance and apparent volume ofdistribution.There was no evidence of accumulation leading tosupratherapeuticconcentrations during this dosing schedule for a mean ofapproximately2–3 days. Br J Anaesth 2000; 85: 512–9 ^* Corresponding author     

Glycopyrrolate treatment of drooling in an adult male patient with cerebral palsy

1. The aim of the study was to assess the effect of glycopyrrolate on drooling in an adult male patient with cerebral palsy. 2. After a thorough medical examination and consent in writing by the responsible guardian, a baseline sum score for frequency and seriousness of drooling was established over a 2 week period in addition to data on shifts of handkerchiefs, urination, defecation and observation of behaviour. Glycopyrrolate (1 mg) tablets were then administered, starting with one tablet daily the third week and increasing the daily dose by one tablet per week until a maximum of four tablets during week six and 4 days of week seven when the daily dose was reduced to two tablets for 3 days. For the four weeks 8-11 three tablets were given daily. In week 12 the dose was reduced to two tablets and for the weeks 13-15 no tablets of glycopyrrolate were given. 3. For as long as the patient received three to four tablets of glycopyrrolate daily, drooling was markedly reduced and handkerchiefs were not necessary on some days. After the tablets were withdrawn drooling increased to approximately the same level as it was before treatment. No adverse medical, psychological, or social effects were observed. 4. For shorter periods, glycopyrrolate can be given in controlled doses provided that an adequate medical assessment has been undertaken.     

Development of oxygen sensitivity in infants of smoking and non-smoking mothers

AIMS: To assess the effect of prenatal cigarette smoke exposure on the postnatal resetting of oxygen sensitivity in term infants. METHODS: 15 healthy term infants of smoking mothers (median 10 cigarettes/day) and 16 controls were studied during quiet sleep 1, 3, and 10 days and 10 weeks postnatally. Strain-gauge respiratory trace was continuously recorded. Repeated 15-s challenges with 100% O2 and 15% O2 were presented in randomised order through a face mask. A median of six hyperoxic and six hypoxic challenges per recording were obtained. Breath-by-breath ventilation in a time-window from 20 s before onset of stimulus to 60 s after was extracted. For each infant at each age, the normalised coherently averaged response to hyperoxia and hypoxia was calculated. Mean ventilation at end of the 15-s stimulus was analysed with ANOVA, as were parameters describing a function fitted to each averaged response. RESULTS: During air breathing, smoke-exposed infants had higher respiratory rates and lower tidal volumes than controls. Nicotine concentration in infant hair, measured by gas chromatography, was positively correlated with maternal level of smoking. A long-term development in oxygen sensitivity was demonstrated in both groups. However, neither the time-course nor the magnitude of O2 responses was affected by maternal smoking. Overall, hyperoxia reduced ventilation by 6.3% at day 1, 13.2% at day 3, 29.6% at day 10, and 40.0% at week 10. Transient hypoxia increased ventilation by 3.5%, 3.2%, 6.4%, and 8.8%, respectively, at the four ages studied.