Visceral anomalies in the Meckel syndrome

The visceral abnormalities of 32 autopsied Meckel's syndrome cases were analysed macroscopically and histologically in order to observe the distribution and spectrum of internal abnormalities in this hereditary malformation syndrome. All cases showed the classical triad of central nervous system anomaly, postaxial polydactyly, and cystic kidneys. Five cases were midterm fetuses and 27 cases were perinatal deaths. The kidneys were grossly enlarged in almost all of the cases (29) and showed a uniform histological pattern of fibrocystic proliferation, which is considered characteristic of MS. Fibrosis and proliferation of the bile ducts in the hepatic portal tracts were found in each case. Severe hypoplasia of the male genitalia associated with cryptorchidism was the third consistent anomaly. Derivatives of the müllerian ducts were present in four males, and the initial sex determination of the male infants was sometimes difficult. Epididymal cysts (39%) and ductal dilatation as well as fibrosis of the pancreas (31%) were further common anomalies. This series showed that a number of gross and microscopic abnormalities are consistently present in MS and that histological investigation is invaluable in defining the syndrome in doubtful cases.     

Plant colonization of a bare peat surface: population changes and spatial patterns

Abstract. Changes in size and spatial arrangement of plant populations established on an initially bare peat surface were described over a period of 5 yr by following plant individuals on a 1-cm grid in an area of 10 m x 25 m. The spatial pattern of populations and association between species was analyzed statistically. The study site was very slowly colonized by 14 perennial plant species. The early successional stage was dominated by Carex rostrata, with a clumped spatial distribution, and the homogeneously distributed Eriophorum vaginatum and Pinus sylvestris. Both the growth in size of populations and changes in their spatial distribution were interpreted as a result of species dispersal ability, tolerance to severity of the substrate and pattern of reproduction.     

Effects of artificial plant cover on plant colonization of a bare peat surface

Abstract. This paper describes the effect of artificial plant cover on plant colonization of a bare peat surface, resulting from peat harvesting. Plant species colonization was compared on plots supplied with plastic models simulating Vaccinium vitis-idaea plants and plots without this artificial cover. After two growing seasons, species composition and total biomass of the established plant cover were similar in the two plot types. However, the number of established seedlings in the plots with artificial cover was significantly higher than that in the plots without cover. Out of 13 species observed four differed significantly in their performance on the two plot types. Betula spec. had both higher seedling numbers and higher biomass on the test plots; Deschampsia cespitosa had a higher biomass, whereas the seedlings were too numerous to be counted; Salix phylicifolia had higher seedling numbers. On the contrary, the number of seedlings of Epilobium angustifoliwn was lower on plots with artificial cover. It is suggested that colonization by Betula, D. cespitosa and S. phylicifolia was facilitated mainly by the improved microclimatic and soil moisture conditions under the artificial plant cover. On the other hand, germination of E. angustifolium may be negatively influenced by the increased shade on the test plots.     

Socioeconomic conditions in childhood and ischaemic heart disease during middle age.

OBJECTIVE--To examine the association between socioeconomic conditions in childhood and ischaemic heart disease in middle aged men, including the role of physiological and behavioural risk factors. DESIGN--Prevalence study with extensive examination and testing and with recall of childhood conditions. SETTING--Population based study in Kuopio, Finland. SUBJECTS--Representative sample of 2679 men aged 42, 48, 54, and 60. MAIN OUTCOME MEASURES--Ischaemic findings on progressive maximal exercise test. RESULTS--Low socioeconomic style in childhood was associated with significantly higher prevalence of findings indicating ischaemias. Compared with those in the highest tertile of childhood socioeconomic conditions, the age adjusted odds ratio for subjects in the lowest tertile was 1.44 and for those in the middle tertile 1.35. Adjustment for years of cigarette smoking times the average number of cigarettes smoked, ratio of high density lipoprotein to low density lipoprotein cholesterol, fibrinogen and serum selenium concentrations, and adult height did not appreciably weaken the association. Adjustment for adult socioeconomic state resulted in a 16% decline in the association. The association was reduced to non-significance by adjustment for measures of prevalent cardiovascular illness. CONCLUSIONS--Socioeconomic state in childhood was significantly associated with ischaemic heart disease in middle aged men. Levels of risk factors measured at middle age did not account for this association, nor did adult height. Because childhood socioeconomic conditions precede the development of ischaemic heart disease the substantial impact of prevalent illness on the observed association suggests that ischaemic heart disease develops earlier in those with lower socioeconomic state during childhood.