Does hypertension or a previous myocardial infarction influence the blood pressure and heart rate responses to changes in body position? Results from a study with serial measurements in the supine and standing positions in 60-year-old men.

An age-related attenuation of the normal increase in diastolic blood pressure and heart rate upon standing has previously been observed in man. Whether this is due to ageing as such, or a consequence of a higher prevalence of cardiovascular disease in older compared to younger subjects, is unclear. This population-based study was conducted to address this question. It was carried out in three groups of 60-year-old men: (i) with hypertension (n = 75), (ii) with a previous myocardial infarction (n = 39), and (iii) without any of these diseases, thus constituting a control group (n = 41). Blood pressure and heart rate were assessed during three 7-min periods (supine-standing-supine), using an unbiased non-invasive method. The cardiovascular responses were both qualitatively and quantitatively similar in all three groups, i.e. the increases in diastolic blood pressure and heart rate upon standing, and decreases upon laying down, were of a similar magnitude. In conclusion, 60-year-old men with hypertension or a previous myocardial infarction had blood pressure and heart rate responses similar to those of men of the same age who did not have these diseases. This indicates that the attenuated response previously reported in older compared to younger people is not explained by the higher prevalence of these cardiovascular diseases in the elderly, but is merely an age-dependent characteristic.

Age-related differences in blood pressure and heart rate responses to changes in body position: results from a study with serial measurements in the supine and standing positions in 30-, 50- and 60-year-old men.

This population-based study presents the blood pressure and heart rate responses to sudden changes in body position in representative groups of men aged 30 (n = 50), 50 (n = 44) and 60 (n = 69) years, using an unbiased method for non-invasive blood pressure measurements. Blood pressure and heart rate were measured every minute during three 7-min periods in the supine, standing and again supine positions. Whereas there was an initial decrease in systolic blood pressure upon standing in men aged 50 and 60 years, an increase was seen in the 30-year-olds. The diastolic blood pressure increased in all age groups, but less in the older compared to the younger men. In all age groups, the changes in systolic blood pressure upon standing were transient, while the changes in the diastolic blood pressure lasted during the entire observation period. The heart rate increased to a similar extent upon standing in all age groups. No symptomatic hypotension was observed. After resuming the supine position, both blood pressure and heart rate returned towards the levels initially recorded. This population-based study confirms previous observations in selected subjects of age-related attenuation in blood pressure response to change in body position. The study also shows that blood pressure and heart rate are rapidly stabilized upon standing up.

Life cycle of the endoparasitic nematophagous fungus Meria coniospora: a light and electron microscopic study.

The obligate endoparasitic fungus Meria coniospora lives its entire vegetative life within infected nematodes. Conidia of M. coniospora infect the nematode Panagrellus redivivus mainly in the mouth region. The infection, starting with adhesion of conidia to the nematode surface, growth of trophic hyphae, production of conidiophores and conidia, was followed using light, scanning and transmission electron microscopy.

The ultrastructure of the cellulolytic bacterium Cellvibrio fulvus.

Thin sections of the cellulolytic bacterium Cellvibrio fulvus were investigated before and after treatment with polymyxin B and Triton X-100. The Gram-negative vibrio appeared to have no separate stained g2 layer between the L and C membranes. Cells lysed after treatment with polymyxin or swelled in the presence of 5% sucrose. Blebs were formed from the L membrane, and the inner structure of the cells changed. Triton X-100 lysed cells even in the presence of 20% sucrose. The flagellum disappeared before lysis; one of the membranes was dissolved; and no organized inner structure could be seen.

Ultrastructure of a thermotolerant basidiomycete possibly suitable for production of food protein.

The imperfect cellulolytic fungus Sporotrichum pulverulentum, which is commonly found growing in wood-chip piles, was grown in submerged culture on wheat shorts and other cereal flours. These substrates were broken down in 1 to 4 days at 30 to 40 C, and the mycelial mass was easily harvested by filtration. Scanning electron micrographs of hyphae in mycelial pellets are presented, and thin sections of conidia and hyphae were studied in a transmission electron microscope. Dolipores in septa of hyphae were observed, and cell walls are shown to be lamellar, which is characteristic of the Basidiomycetes. Actively growing hyphae are full of cytoplasm with numerous mitochondria, whereas old mycelial pellets contain highly vacuolated and almost empty cells.