Children with screening-detected coeliac disease show increased levels of nitric oxide products in urine.

AIM: Increased concentration of nitric oxide (NO) metabolites, nitrite and nitrate, in the urine is a strong indication of ongoing small intestinal inflammation, which is a hallmark of the enteropathy of coeliac disease (CD). It has previously been shown that children with symptomatic, untreated CD have increased levels of NO oxidation products in their urine. The aim of this study was to investigate whether screening-detected, asymptomatic coeliac children display the same urinary nitrite/nitrate pattern. METHODS: In a multicenter screening study, serum samples were collected from 7208 12-year-old children without previously diagnosed CD. Sera were analysed for anti-human tissue transglutaminase (tTG) of isotype IgA. Small bowel biopsy was performed in antibody-positive children, yielding 153 new cases of CD. In the screening-detected individuals, the sum of nitrite and nitrate concentrations in the urine was analysed and used as an indicator of NO production. For comparison, 73 children with untreated, symptomatic CD were studied. RESULTS: The nitrite/nitrate levels in children with screening-detected CD and those with untreated symptomatic CD did not differ significantly. Both groups had significantly increased urinary nitrite/nitrate concentrations compared to the children with normal small bowel biopsy (p < 0.001). CONCLUSION: Children with screening-detected CD have increased production of NO just as children with untreated symptomatic CD. High NO metabolite levels in the urine may indicate a pathogenetic feature of CD and be a marker of major clinical importance.

Evaluation of Gentian cystatin C reagent on Abbott Ci8200 and calculation of glomerular filtration rate expressed in mL/min/1.73 m(2) from the cystatin C values in mg/L.

OBJECTIVE: Estimation of the glomerular filtration rate (GFR) is essential when evaluating patients with kidney disease and treating patients with drugs eliminated from the circulation by the kidneys. Cystatin C has been shown in several studies to be superior to creatinine in the estimation of GFR. At our hospitals, there is an increasing demand for cystatin C and at present we perform approximately 1500 cystatin C analyses a month. We thus need the assay available 24 h/day and to have it on our routine chemistry instrument to minimize handling time per test and time to reported test results. MATERIAL AND METHODS: We have evaluated a new cystatin C immunoassay from Gentian (Gentian, Moss, Norway) on Architect ci8200 (Abbott Laboratories, Abbott Park, Ill., USA). A prerequisite at our hospital is that cystatin C results are reported as a calculated GFR in mL/min/1.73 m(2), so we also made a comparison with iohexol clearance. RESULTS: The Gentian cystatin C assay showed good agreement with the corresponding assay from Dade Behring (Deerfield, Ill., USA) and good inter-laboratory concordance. The assay has very low total imprecision, good linearity and strong correlation with iohexol clearance (R (2) = 0.956). The equation for the correlation curve is: y = 79.901x(-1.4389). CONCLUSIONS: There was low inter-laboratory variation between the three laboratories involved in the cystatin C evaluation, and thus all three laboratories can use the same equation for calculating the estimated GFR.

Small bowel biopsy in Swedish paediatric clinics.

AIM: A correct diagnosis of coeliac disease, one of the most common chronic diseases in Swedish children, demands small bowel biopsy, which can be performed endoscopically or by means of a peroral capsule. Recently there was a debate among Swedish paediatric gastroenterologists, with some advocating the cessation of capsule biopsy in favour of endoscopic biopsies. To gain information on which to base a recommendation for which technique to use, the Swedish Working Group for Childhood Coeliac Disease was commissioned to carry out a national questionnaire study on current small bowel biopsy routines in Swedish paediatric clinics. METHODS: A questionnaire concerning biopsy routines in the year 2000 was sent to all paediatric clinics performing biopsies. A reply was obtained from 39 of 40 clinics, covering 98% of the Swedish population. RESULTS: Some 1400 biopsies were performed, 64% of which were capsule biopsies and 36% endoscopic. Three clinics performed all biopsies endoscopically and 11 clinics all via a capsule. At endoscopy all children were under deep sedation or full anaesthesia, while most children undergoing capsule biopsy were under light or deep sedation. The oxygen saturation was monitored during endoscopy but less often or never during routine capsule biopsy. The presence of the parents during biopsy varied according to the degree of sedation: at 97% of the clinics performing capsule biopsy on children under light sedation, the parents were present during the whole procedure, whereas no parents were present at clinics where the biopsy was performed endoscopically under anaesthesia. CONCLUSION: Compared with the results of a similar questionnaire concerning biopsy routines performed in the early 1990s, children are now more effectively sedated. Furthermore, there is an obvious trend from capsule towards endoscopic biopsy. Both the endoscopic and the capsule biopsy techniques are useful and satisfactory for obtaining small bowel mucosal samples providing that the children are effectively sedated. For practical and economic reasons the capsule biopsy technique will probably continue to be used, although to a lesser extent than today.

Screening of neonatal instability and of developmental dislocation of the hip. A survey of 132,601 living newborn infants between 1956 and 1999.

Between 1956 and 1999, 132,601 living children were born in Malmö, and screened for neonatal instability of the hip. All late diagnosed patients have been followed and re-examined clinically and radiologically. During the first years of screening, less than five per 1,000 living newborn infants were treated. This figure increased to 35 per 1000 in 1980, but later diminished again to about six per 1,000 annually after 1990. The number of referred cases decreased from 45 per 1,000 in 1980 to between 10 to 15 per 1,000 from 1990. During the period of high rates of referral and treatment a larger number of paediatricians were involved in the screening procedure than during the periods with low rates of ferral and treatment. Altogether 21 patients (0.16 per 1,000) with developmental dislocation of the hip were diagnosed late, after one week. At follow-up, 18 were free from symptoms and 15 considered to be diologically normal.

The influence of complexing agents on the solubility and absorption of aluminium in rats exposed to aluminium in water.

The influence of citrate (0-31 mM), fluoride (0 or 2.6 mM) and silicate (0 or 2.6 mM) on the absorption of Al (0-18 mM) was studied in rats. We tested the hypothesis that the solubility and absorption of Al increases in the gastrointestinal (GI) tract in the presence of the complexing agents. Male rats were exposed for 6 or 7 weeks to soluble Al in acidic drinking water (pH 2.5-3.0) with or without the complexing agents. At the end of exposure Al was fractionated in the stomach content, in order to study if the solubility of Al was changed after ingestion. Al absorption was estimated by Al analysis of the right femur bone. Speciation calculations indicated that citrate and fluoride caused formation of soluble Al-citrate (97%) and -fluoride (> 60%) complexes in the water. Silicate did not affect the theoretical speciation. In all cases, a large fraction of soluble Al became insoluble in the stomach after ingestion. The concentration of soluble Al increased only in the presence of citrate or a mixture of fluoride and silicate, but citrate was the only complexing agent that influenced the absorption of Al in the rat. This indicates that the form of Al may be changed in the GI tract when soluble drinking-water Al is ingested, and that the solubility of Al in drinking water and GI tract may not be good predictors of the bioavailability of Al even when chelating agents are present.

A central core structure in an antibody variable domain determines antigen specificity.

Antibody binding sites provide an adaptable surface capable of interacting with essentially any molecular target. Using CDR shuffling, residues important for the assembly of mucin-1 specific paratopes were defined by random recombination of the complementarity determining regions derived from a set of mucin-1 specific clones, previously selected from an antibody fragment library. It was found that positions 33 and 50 in the heavy chain and 32, 34, 90, 91 and 96 in the light chain were conserved in many of the clones. These particular residues seem to be located centrally in the binding site as indicated by a structure model analysis. The importance of several of these conserved residues was supported by their presence in a mouse monoclonal antibody with a known structure and the same epitope specificity. Several of these corresponding residues in the mouse monoclonal antibody are known to interact with the antigen. In conclusion, critical residues important for maintaining a human antigen-specific binding site during the process of in vitro antibody evolution were defined. Furthermore, an explanation for the observed restricted germline gene usage in certain antibody responses against protein epitopes is provided.

Late-diagnosed DDH: a prospective 11-year follow-up of 71 consecutive patients (75 hips).

I have prospectively studied 71 consecutive patients (75 hips) with late-diagnosed DDH (developmental dysplasia of the hip) treated uniformly with special reference to the development of the femoral head and the acetabulum. The age at the start of treatment was 10 (2-64) months. The follow-up time was 11 (6-18) years. After tenotomy and traction, closed reduction failed in 7 hips. These cases were treated by open reduction with or without Salter innominate osteotomy-in 2 hips femoral osteotomy was also done (shortening, varus and derotation). 1 hip subluxated and 1 re-dislocated after closed reduction. Avascular necrosis occurred in 4 hips and additional surgery was required in 12 hips--11 Salter osteotomies, 1 varus femoral osteotomy. In the first year after reduction, the acetabular angle improved rapidly--faster in the younger children. When treatment started between 12 and 22 months, the improvement was slower and the final outcome more unpredictable. The femoral head continued to grow irrespective of the age at reduction and became normal in almost all cases. Salter's innominate osteotomy stabilized hips after open reduction and gave excellent results in cases with an increasing acetabular angle. At the last re-examination, all but 2 patients were asymptomatic. Radiographically, 65 hips were rated Severin group I, 9 group II and 1 group III.

Recombining germline-derived CDR sequences for creating diverse single-framework antibody libraries.

We constructed a single-chain Fv antibody library that permits human complementarity-determining region (CDR) gene fragments of any germline to be incorporated combinatorially into the appropriate positions of the variable-region frameworks VH-DP47 and VL-DPL3. A library of 2 x 109 independent transformants was screened against haptens, peptides, carbohydrates, and proteins, and the selected antibody fragments exhibited dissociation constants in the subnanomolar range. The antibody genes in this library were built on a single master framework into which diverse CDRs were allowed to recombine. These CDRs were sampled from in vivo-processed gene sequences, thus potentially optimizing the levels of correctly folded and functional molecules, and resulting in a molecule exhibiting a lower computed immunogenicity compared to naive immunoglobulins. Using the modularized assembly process to incorporate foreign sequences into an immunoglobulin scaffold, it is possible to vary as many as six CDRs at the same time, creating genetic and functional variation in antibody molecules.

Instability of the hip in neonates. An ethnic and geographical study in 24,101 newborn infants in Malmö.

In a prospective study conducted between 1990 and 1997, 24 101 newborn infants were examined for neonatal instability of the hip and classified by the ethnic origin of their parents. In 63% their mother and father were of Swedish extraction and in 24% they were born in a foreign country. Those of foreign extraction were split into ethnic and geographical subgroups. Although the incidence of treated (dislocatable-unstable) hips was greater in Swedes (7.6/thousand), than in other geographical groups (5.8/thousand) it was not significantly different (p = 0.065). A total of 12.7/thousand were referred from the neonatal ward to the orthopaedic clinic with suspected dislocatable or unstable hips; 6.8/thousand were treated (5.4/thousand dislocatable, 1.4/thousand unstable), but 5.9/thousand were not treated since their ultrasound examination was normal. Two hips were diagnosed late and one case of mild avascular necrosis was found. Examination by dynamic ultrasound decreased the number of treated cases by 5.9/thousand but was not an absolute guarantee of diagnosis.

Epidemic of coeliac disease in Swedish children.

Coeliac disease has emerged as a public health problem. The aim of the present study was to analyse trends in the occurrence of symptomatic coeliac disease in Swedish children from 1973 to 1997, and to explore any temporal relationship to changes in infant dietary patterns. We established a population-based prospective incidence register of coeliac disease in 1991, and, in addition, retrospective data from 1973 were collected. A total of 2151 cases fulfilled the diagnostic criteria. Furthermore. We collected national data on a yearly basis on duration of breastfeeding, intake of gluten-containing cereals and recommendations on when and how to introduce gluten into the diet of infants. From 1985 to 1987 the annual incidence rate in children below 2 y of age increased fourfold to 200-240 cases per 100000 person years, followed from 1995 by a sharp decline to the previous level of 50-60 cases per 100000 person years. This epidemic pattern is quite unique for a chronic disease of immunological pathogenesis, suggesting that prevention could be possible. The ecological observations made in this study are compatible with the epidemic being the result, at least in part, of a change in and an interplay among three factors within the area of infant feeding, i.e. amount of gluten given, age at introduction of gluten, and whether breastfeeding was ongoing or not when gluten was introduced. Other factor(s) may also have contributed, and the search for these should be intensified.

Does aluminium stimulate the immune system in male rats after oral exposure?

The influence of oral aluminium exposure on the immune system was studied in rats. Male rats were exposed to soluble and labile Al in acidic drinking water (0-500 mg Al/l) for 7-9 weeks. The concentration of Al in femur bone was higher in rats exposed to 50 and 500 mg Al/l (mean concentration 277 and 599 ng Al/g) than in control rats (150 ng Al/g). The Al concentration in blood plasma could only be quantified in the 500 mg/l group (mean 2.7 ng/ml), whereas the concentrations in the control and 50 mg/l groups were low (< 2 ng Al/ml). Exposure of 4-13-weeks-old rats to the highest Al concentration caused an increased number of splenocytes, whereas exposure of 9-16-weeks-old rats to 500 mg Al/l caused an increased number of thymocytes. Moreover, the proliferative response of splenocytes to the mitogen Con A (2 micrograms/ml) was increased by exposure of the 9-16-weeks-old rats to 500 mg Al/l as compared with the controls. The results indicate that oral Al exposure caused a slight stimulation of some immune functions in the rat at Al plasma concentrations normally found in the human population (< 10 ng Al/ml).

Concentration-dependent absorption of aluminum in rats exposed to labile aluminum in drinking water.

The hypothesis was tested that the absorption of labile Al in rats will increase when the Al-binding capacity of food components in the stomach is saturated. Male rats were exposed to 0, 10, 50, or 500 mg labile Al/L in acidic drinking water (pH 3) for 9 wk. The results show that labile Al in drinking water is complexed by feed constituents in the stomach of the rat in vivo, thus causing a nondetectable absorption of Al at 10 mg Al/L. An increased absorption of Al at 50 and 500 mg Al/L was associated with a saturation of the Al-binding capacity of feed components in the lumen of the stomach, causing the appearance of labile Al. Thus, the presence of labile Al in drinking water does not necessarily result in a high Al absorption when the water is ingested, since the bioavailability of labile Al is dependent both on the amount and composition of Al-binding components present in the gastrointestinal tract at the time of ingestion of the water. It is thus not possible to predict the body burden of Al in humans just by measuring the Al concentrations in drinking water. Even a further refining of the exposure measurement to include speciation of Al in the water may not markedly improve the prediction of the Al body burden. Future epidemiological studies must therefore be based on actual measurements of Al concentration in tissues or fluids from the study subjects.

Effective Sample Size in Diffuse Reflectance Near-IR Spectrometry.

Two independent methods for determination of the effectively sampled mass per unit area are presented and compared. The first method combines directional-hemispherical transmittance and reflectance measurements. A three-flux approximation of the equation of radiative transfer is used, to separately determine the specific absorption and scattering coefficients of the powder material, which subsequently are used to determine the effective sample size. The second method uses a number of diffuse reflectance measurements on layers of controlled powder thickness in an empirical approach. The two methods are shown to agree well and thus confirm each other. From the determination of the effective sample size at each measured wavelength in the visible-NIR region for two different model powder materials, large differences was found, both between the two analyzed powders and between different wavelengths. As an example, the effective sample size ranges between 15 and 70 mg/cm(2) for microcrystalline cellulose and between 70 and 300 mg/cm(2) for film-coated pellets. However, the contribution to the spectral information obtained from a certain layer decreases rapidly with increasing distance from the powder surface. With both methods, the extent of contribution from various depths of a powder sample to the visible-NIR diffuse reflection signal is characterized. This information is valuable for validation of analytical applications of diffuse reflectance visible-NIR spectrometry.

Cystatin F is a glycosylated human low molecular weight cysteine proteinase inhibitor.

A previously undescribed human member of the cystatin superfamily called cystatin F has been identified by expressed sequence tag sequencing in human cDNA libraries. A full-length cDNA clone was obtained from a library made from mRNA of CD34-depleted cord blood cells. The sequence of the cDNA contained an open reading frame encoding a putative 19-residue signal peptide and a mature protein of 126 amino acids with two disulfide bridges and enzyme-binding motifs homologous to those of Family 2 cystatins. Unlike other human cystatins, cystatin F has 2 additional Cys residues, indicating the presence of an extra disulfide bridge stabilizing the N-terminal region of the molecule. Recombinant cystatin F was produced in a baculovirus expression system and characterized. The mature recombinant protein processed by insect cells had an N-terminal segment 7 residues longer than that of cystatin C and displayed reversible inhibition of papain and cathepsin L (Ki = 1.1 and 0.31 nM, respectively), but not cathepsin B. Like cystatin E/M, cystatin F is a glycoprotein, carrying two N-linked carbohydrate chains at positions 36 and 88. An immunoassay for quantification of cystatin F showed that blood contains low levels of the inhibitor (0.9 ng/ml). Six B cell lines in culture secreted barely detectable amounts of cystatin F, but several T cell lines and especially one myeloid cell line secreted significant amounts of the inhibitor. Northern blot analysis revealed that the cystatin F gene is primarily expressed in peripheral blood cells and spleen. Tissue expression clearly different from that of the ubiquitous inhibitor, cystatin C, was also indicated by a high incidence of cystatin F clones in cDNA libraries from dendritic and T cells, but no clones identified by expressed sequence tag sequencing in several B cell libraries and in >600 libraries from other human tissues and cells.

[Proposed criteria for diagnosis of celiac disease in children]. / Förslag till kriterier för celiakidiagnos hos barn.

At a seminar arranged in September 1997 by the Swedish Paediatric Working Group for Coeliac Disease, a diagnostic protocol proposed by the working group was approved by a majority of the paediatricians present, representing almost all paediatric units in Sweden. Briefly, a small bowel biopsy is called for in all children, both at presentation and as a control during gluten-free dieting. Subsequent gluten challenge and biopsy are mandatory only in cases of atypical presentation or if the diagnosis is questioned at some future date. Serum antigliadin and anti-endomysial antibody tests are complementary tools. Agreement was also reached regarding the institution of a national coeliac disease registry.

Evaluation techniques for two-way data from in situ fourier transform mid-infrared reaction monitoring in aqueous solution.

A model chemical reaction was monitored with in situ Fourier transform mid-infrared spectroscopy using an attenuated total reflectance probe. The evaluation of the IR spectra is complicated by the fact that the reaction runs in nonisothermal aqueous solution with large variations in pH. Despite this, it was possible to extract large amounts of useful information on the reaction after suitable pretreatment of the spectra. Alternating least-squares (ALS) multivariate curve resolution is shown to be a useful technique for obtaining pure component spectra and concentrations if suitable spectral regions are analyzed. Rank mapping methods are used as the basis for this sectioning into smaller regions. Techniques for finding and analyzing selective spectral regions are also shown to be applicable to this type of data. Partial least-squares (PLS) regression models based on spectral data were used to verify the results where possible. The correlation between the concentrations predicted from PLS and ALS is excellent.

Prevalence of coxarthrosis in an urban population during four decades.

In the current study, in a survey of 4121 double contrast radiographs of the colon performed from 1987 through 1995, the hip joints were examined and classified with regard to the presence or absence of primary coxarthrosis. The data collection was performed in precisely the same manner as in two earlier studies undertaken on 3903 radiographs of the colon covering the years 1956 through 1962 and 4027 radiographs of the colon covering the years 1975 through 1982. In the current study the prevalence of coxarthrosis, the gender ratio, and distribution between bilateral and unilateral cases had not changed compared with the data from the two earlier studies. When pooling the three investigations, the age specific prevalence of primary coxarthrosis based on the 12,051 radiographs fits an exponential curve for which the prevalence of primary coxarthrosis increased from below 1% in the age group younger than 55 years to 10% in the age group older than 85 years. In the current study approximately half of the patients (55%) had undergone total hip arthroplasty. This was more than in the study from 1984 (35%). Among the surgically treated patients, lateral coxarthrosis was more common than was medial coxarthrosis.