Transmission electron microscopy of early microbial colonization of human enamel and root surfaces in vivo

Abstract – This study describes the early microbial colomization of teeth by the use of light-and transmission electron microscopy. Six dental students carried a total of 60 test pieces of unerupted enamel and root surface in intraoral acrylic appliances for 4, 8, 12, 24 and 48 h, during which periods oral hygiene was abandoned. Pronounced variations were recorded in structure and thickness of the pellicle across the individual surfaces of both dental tissues. Bacterial single-cell colonization increased the electron density of the adjoining pellicle. Micro-colonies of bacteria were observed in relation to enamel surface irregularities such as perikymata, while the distribution on root surfaces appeared incidental. Root surfaces were generally colonized by thicker deposits than homologous enamel surfaces although the structural composition of the microbiota was similar. Gram-positive bacteria with thick cell walls appeared in coccoid or rod-shaped configurations depending on the age of the bacterial deposit. These bacteria were further characterized by selective invasion between collagen fibers. After 48 h the complexity of the microbiota was increased by the establishment of new bacterial species in the superficial layer. It is concluded that the pattern and composition of the early microbiota on teeth is more complex and variable than hitherto assumed.     

Sibling sex ratio of individuals diagnosed with autism spectrum disorder as children

Aim To study the sex ratio (proportion of males) in siblings of individuals diagnosed with autism spectrum disorders (ASDs) as children. Method In the current study, we extended previous studies dealing with the androgen theory of autism and examined sex ratios in the siblings of 326 individuals with ASD (245 males, 81 females) who had been consecutively assessed at two Danish university clinics of child psychiatry during the 25‐year period from 1960 to 1985. Results Among the 513 siblings, 300 were males and 213 females. This yields a sex ratio of 0.585, which is significantly higher than the Danish live‐birth sex ratio over the same period (0.514, p=0.001). The sibling sex ratio was not associated with the IQ in the autistic probands. Interpretation Our findings suggest a potential indirect confirmation of the androgen theory of autism.     

HOW TO EVALUATE CLINICAL PARAMETERS AT A GLANCE

Schiøtz, P.O., Beck, B. and Pedersen, M. (Paediatric Department TG, Rigshospitalet, Copenhagen, Denmark). How to evaluate clinical parameters at a glance. Acta Paediatr Scand 1982; suppl 301: 121-124. — A brief introduction is given to the practical approach in cystic fibrosis patient care, which is used at the Danish Cystic Fibrosis centre employing Dr. Flensborg's flowsheets.     

Social characteristics of urban cafe guests in Norway

Which factors may influence the number of hours spent per week in cafes, and the amount of alcohol consumed in licensed premises, by urban cafe guests in Norway? In 1991 a comprehensive questionnaire survey was undertaken among 1053 visitors to 41 licensed cafes in Oslo, Norway. The five most important predictors of time spent in cafes were: household situation (β=0.20), occupation (β= 0.18), personal economic resources and sex (both β= 0.15) and age (β= 0.11). These factors were also significant predictors of the number of days during the past 4 weeks the respondents had drunk jour glasses or more of alcohol in cafes. Men, people living with others, people with poor economic resources and people not engaged in paid employment or education were the ones who reported spending the most hours per week and the most episodes of “heavy” drinking in cafes during a 4-week period. Visiting and drinking in cafes may be a way of structuring everyday life.     

GROWTH, BODY WEIGHT AND INSULIN REQUIREMENT IN DIABETIC CHILDREN

ABSTRACT. The weight and height development of 51 boys and 48 girls who had developed diabetes prior to the age of 15 years was followed for a minimum of 3 years, mean 8.3 years, up to the age of 18 for the girls and 20 for the boys. In addition, the insulin requirements were recorded. Weight and height proved to be within the normal range, and height at onset of diabetes was normal. After a long duration of diabetes, however, there occurred a reduction of height increment of about 1/2 cm/year. This reduction was greater in children who rarely attended as compared with those who frequently attended a sub-specialized clinic. The daily dose of insulin increased with age, the greatest increase coinciding with the growth spurt. During the first 4 years of diabetes the 24-hour dose/kg body weight increased, indicating a decreasing endogenous insulin production. Later it was constant at around 0.9 i.u./kg. Modern management of diabetic children leads to normal adult stature.     

Data on the HL-A linkage group

Lod scores from a study in 229 families of the linkage relations of HL-A-PGM3 to 19 marker loci and cystic fibrosis are reported. The data exclude that ADA belongs to this linkage group while they give weak support for the inclusion of P. There is weak evidence for linkage of cystic fibrosis to PGM3, but none for linkage to HL-A. No new suggestive linkages appeared.