[Neonatal lupus syndrome. Association with complete congenital atrioventricular block]. / Neonatal lupus-syndrom. Association til kongenit totalt atrioventrikulaert blok.

Neonatal lupus erythematosus (NLE) is characterized by persistent congenital complete heart block, often without any other structural heart defects. Lupus-like dermatitis is seen transiently, more rarely hepatitis and thrombocytopenia occurs. Recent investigations have shown a close relation between NLE and maternal anti-Ro/La antibodies. These antibodies seem responsible for the destruction of the bundle of His and the AV node in the foetus. Total AV block is seen in 1:15.-22,000 of liveborn children, 70-90% of them are caused by NLE. It is difficult to identify the pregnancies at risk since at delivery most of the mothers (up to 66%) are without symptoms. If the mother has anti-Ro/La antibodies the risk for having a child with NLE is probably less than 5%. However, new investigations have shown that mothers who in addition have anti-DNA antibodies have significantly lower risk of bearing a child with NLE. In most cases foetal complete AV block is found accidentally during pregnancy. Slow foetal heart rate with the demonstration of AV dissociation should not, unless the foetus shows sign of incompensation, lead to acute delivery, but pregnancy should be monitored carefully by serial echocardiography. More than half of the children with congenital heart block need pacemaker therapy shortly after birth. The other children should be followed closely for signs of incompensation and may need pacemaker therapy later on.

Influence of growth conditions on the value of crisphead lettuce. 4. Quality changes during storage.

Crisphead lettuce (Lactuca sativa L. var capitata cvs. Marius and Saladin) were grown with a nitrogen supply from 50 to 200 kg N/hectare. Heads were stored for one or two weeks at 1 degree C in cold storage or ice bank cooling. Samples were taken for measurement of dry matter, sugars, vitamin C and nitrate. The content of dry matter, sugars (glucose, fructose) and vitamin C decreased with increasing level of nitrogen, and the content of nitrate increased. Except for nitrate the contents of the other quality attributes decreased at all nitrogen supply levels during storage. No differences were found between the storage systems, and beside fructose no significant differences were found between the two cultivars. The content of dry matter, vitamin C, and nitrate decreased from the outer to the inner head fraction, while the content of sugars increased. Trimming decreased the content of dry matter, vitamin C and nitrate and increased the content of sugars. To obtain heads from storage with a relatively high content of dry matter, sugars and vitamin C, and a relatively low content of nitrate the nitrogen supply must be as low as possible. Except for nitrate where no distinct results were found in this experiment it must also be recommended to store the heads as short time as possible. Possibly the cv. Saladin has some advantage quality attributes after storage compared with the cv. Marius.

Influence of growth conditions on the value of crisphead lettuce. 1. Marketable and nutritional quality as affected by nitrogen supply, cultivar and plant age.

The marketable and nutritional quality of crisphead lettuce as affected by nitrogen supply, cultivar, and plant age at harvest was investigated in six plantings during 1989 and 1990. The optimum yield of marketable heads was obtained at a total nitrogen supply of 150 kg N per ha although only small differences were observed to the yield at 100 and 200 kg total N per ha. The total nitrogen supply included the amount of mineral nitrogen within the rhizosphere. The incidence of dry tipburn in older leaves was clearly decreased by an increased nitrogen supply, especially at late planting. The content of nitrate was increased and the content of dry matter and vitamin C decreased with increased nitrogen supply. The vitamin C content was higher for the cultivar 'Marius' than for 'Saladin'. As plants got older, the nutritional quality of crisphead lettuce decreased because the content of nutrients, especially vitamin C, decreased with increased plant age at harvest.

Influence on growth conditions on the value of crisphead lettuce. 2. Weight losses during storage as affected by nitrogen, plant age and cooling system.

Storage of crisphead lettuce was carried out at 1 degrees C in an ordinary cold storage room and in an ice bank cooling system. The plants were grown at three plantings at 50, 100, 150 and 200 kg total nitrogen supply per hectare and harvested at two or three different plant ages. The cultivars used were 'Marius' and 'Saladin'. The aim of the experiment was to prolong the storage and to reduce the losses. After 14 days of storage the greatest total weight losses were found at the mid-season planting whereas the least total weight loss was found at the late planting. Ice bank cooling at all plantings reduced the total weight loss in comparison to the cold storage. The effect of nitrogen and cultivar was low. The total weight loss defined as loss due to transpiration and trimming was neither related to the head weight nor the surface area of the heads. A reduced loss with increasing plant age was not a question of increased transpiration due to surface to volume ratio changes, but may be related to other factors. A lower average total weight loss was found in the ice bank cooling system compared to the cold storage. The explanation of this might be the existence of a high relative humidity in the ice bank storage. To reduce the total weight loss harvest must take place at the right plant age. No definite growth stage was defined here, but the plants must have reached marketable quality as the young plants are more susceptible to weight loss during storage. It seems likely that some unknown internal factors in the plant were involved in reduction of the total weight loss.

[Knowledge about asthma among Danish primary school teachers. Results of a questionnaire study]. / Danske folkeskolelaereres viden om astma. Resultat af en spørgeskemaundersøgelse.

An anonymous questionnaire inquiry performed among 324 school teachers in the Randers area with the purpose of elucidating teachers' knowledge about asthma is presented. To a series of statements about asthma, the teachers should answer yes, no or don't know. A limited knowledge about asthma in children was found. The knowledge about medicamental treatment was particularly limited. Only 57 per cent knew that wheezing after physical exertion is a strong indicator of asthma. Only five per cent had received proper instruction. This latter group had a significantly better knowledge of medical treatment (p < 0.0001-0.05). It is recommended that instruction in children's diseases, especially asthma should be reintroduced in teachers' training colleges.

[Accidental strangulation in a perambulator--again]. / Accidentel strangulation i barnevogn--igen.

Three cases of accidental strangulation of children in prams are described. One of the cases has been described previously. The reason for the strangulation lies in the construction of the pram, so that the actual lower frame is collapsible, and when this occurs, the handle is folded over the collapsed frame. In the cases described, the security mechanisms were insufficient and the children were strangled between the handle and the bassinet. This construction is considered unsuitable and prams with different constructions are recommended.

Child care and children's illness.

This paper uses nationally representative data from the Child Health Supplement of the 1981 National Health Interview Survey to test the hypothesis that the larger the groups in which children receive care, the more days per year they spend in bed due to illness. We estimate a model of annual bed days for children ages six months to two and one-half years old, and separately for children two and one-half to five years old. Our results show significantly higher numbers of bed days for children in day care centers than for children at home for both age groups, controlling for confounding factors. Children in family day care have significantly more bed days than those at home, but only among the younger sample. The negative effect of family day care is less than that of child care centers. Although the relative effect of group care is to increase annual bed days by 30 to 19 per cent, the absolute effect is modest with children in group care having 1.3 to .6 more bed days per year.

Solid-phase radioimmunoassay of immunoglobulins G, A and M: applicability in analysis of sucrose gradients.

A simple and sensitive solid-phase radioimmunoassay for the detection of immunoglobulins G, A and M in sucrose gradients is described. The solid-phase consisted of immunoglobulins adsorbed to polystyrene tubes. Using buffers without detergent and 125I-labeled sheep anti-rabbit IgG as radioligand, the assay was able to detect 0.8 ng per tube in the IgG assay and 1.6 ng per tube in the IgA and IgM assays. Standard curves with antigen dissolved in 10% and 32% sucrose were superimposable and did not deviate from standard curves with antigen dissolved in buffer without sucrose. Using these techniques on ultracentrifugation samples from patients with systemic lupus erythematosus, Schönlein-Henoch nephritis and IgA glorulonephritis it was possible to detect both immunoglobulin fragments and immunoglobulin aggregates at the same time without prior dialysis of the samples.

Anti-IgG antibodies during immunotherapy with purified grass pollen extracts.

In a double blind study 40 patients were allocated specific immunotherapy (hyposensitization) with partially purified timothy extract or two timothy major allergens 19, 25. All patients had typical grass pollen hay fever, in 27% associated with grass pollen asthma and in 13% with birch pollen allergy. Serum IgG anti-IgG antibodies were determined after dithiothreitol treatment. Before hyposensitization, IgG anti-IgG titres greater than or equal to 9 were demonstrated in 45% of the patients. During hyposensitization IgG anti-IgG titres showed a slight initial increase followed by a decrease below pretreatment level. Neither increase nor decrease was statistically significant. Reactions to rabbit IgG F(ab')2 fractions were only obtained during hyposensitization. The occurrence of anti-IgG antibodies did no correlate with symptoms, side effects, or the level of allergen-specific IgG. In a previous study it was demonstrated that patients with multiallergy hyposensitized with combined allergen extracts showed a statistically significant increase in IgG anti-IgG titres during treatment. The increase failed to appear in the present patients allergic only to pollen and treated with purified allergen extracts. It is therefore suggested that a multiallergic condition and the combination and/or purification of allergen extracts administered during hyposensitization may influence the production of IgG anti- IgG antibodies.

Solubility properties of IgG immune complexes. Comparison between the effects of low molecular weight solvents and polyethylene glycols.

A systematic study of the influence of organic solvents on the interaction between human IgG and rabbit anti-human IgG IgG++ has been conducted, using difference turbidity and sucrose gradient centrifugation methods. It was found that very small alcohols like methanol and ethanol increased the turbidity signal, whereas larger alcohols (propanol, isopropanol, propanediol and ethylene glycol) had no influence on the signal. Sucrose, dioxane, dimethylformamide and dimethylsulphoxide decreased the difference turbidity signal. Sucrose gradient centrifugation did not show any influence. Polyethylene glycols were investigated with regard to molecular weights as well as concentrations. In contrast to the low molecular weight solvents, polyethylene glycols with molecular weights from 600 up to 20,000 gave a clearly expressed increase in the development of turbidity as well as in the size of the final turbidity signal. By sucrose gradient centrifugation, it was found that polyethylene glycols of molecular weights from 1000 to 10,000 had a profound effect on the solubility of immune complexes. The influence depended on the molecular weight as well as on the concentration. By use of [14C]-labelled polyethylene glycol it was found that polyethylene glycols did not form stable complexes with immune complexes. Furthermore, it was found that the zoning phenomenon was retained in the presence of small concentrations of polyethylene glycols, but higher concentrations of polyethylene glycols caused even antigen-excess complexes to show turbidity.

Biochemical aspects of immune complex formation and immune complex diseases.

Formation of immune complexes is a normal part of the immune defence against soluble antigens. Immune complexes may nevertheless play a pathogenic role of their own. The present review discusses antigen antibody interactions with special regard to immune complex formation. A new classification of antigen antibody interactions is proposed, based on the antigenic valence. Oligovalent antigens and bivalent antibodies form genuine immune complexes. Experimental observations and theoretical considerations indicate that although a vast variety of complexes is possible genuine immune complex formation is a self-limiting process, so it is typical that the smallest possible complexes are formed in the largest amounts. Formation of immune complexes differs in mechanism from most other biological ligand binding reactions, and the extent to which immune complex formation follows its own laws is discussed. To explain the mechanism of precipitin reactions, a two-stage model is proposed. The outcome of antigen antibody interactions is further complicated because antibody preparations are typically heterogeneous, and the impact of antibody heterogeneity is also discussed.

On the composition of IgG anti-IgG immune complexes.

The formation of different immune complexes of IgG was followed in a system comprising human IgG as antigen and rabbit IgG directed against the Fc portion of human IgG as antibody. Soluble IgG complexes were analyzed by analytical zonal centrifugation. In antigen excess, 16S complexes predominated. 16S complexes are oligomers of IgG, mainly trimers and tetramers. In decreasing antigen excess larger and larger complexes were formed. It was, however, found consistently that oligomers were always formed in the largest amounts. The largest complexes detectable by this method consisted of about twenty IgG molecules. The solubility of different complexes in polyethylene glycol was also studied. Low concentrations of polyethylene glycol preferentially precipitate large complexes. Four and six per cent polyethylene glycol precipitated all types of IgG complexes although not completely. Polyethylene glycol was seemingly not bound directly to soluble immune complexes, but caued otherwise soluble complexes to precipitate by an indirect mechanism.

Ergophthalmological studies in the electronic industry.

162 employees, the majority women, in an electronic industry were examined in a joint study involving several ergonomic aspects. Some results concerning visual skills are here extracted from a more comprehensive report. No natural selection of fitted workers could be demonstrated. The visual function was found to be only one component of a multifactorial system, which determines the psychological and physical well-being and productivity of industrial workers. The lack of a sufficient number of abnormal persons and comparable working conditions made it difficult to define limiting visual standards for job performance. Ordinary tests for visual acuity, near vision, heterophoria and stereopsis revealed few facts of importance. More intersting results were obtained when spectacles were evaluated as suitable for the job. 43% of the spectacles were considered insufficient. The use of bifocals did not seem to be related to the need of head movements, and 68% of all the spectacles had tinted glasses, in spite of the fact that the majority of persons wearing them considered the working illumination inadequate. An analysis of the working posture and the visual capacity of the worker should precede the prescription of spectacles for industrial workers.