ABSTRACT
The anterior descending coronary artery was obtained from each of 160 subjects aged 2 to 30 years who died suddenly. The arteries were examined for early atheromatous changes and the mothers were asked about the way the children had been fed during early infancy. No evidence was found for the hypothesis that breast feeding confers protection against coronary artery disease. The mothers' smoking history at the time of the birth bore no relationship to the pathological findings in the arteries. It therefore seems unlikely that the type of feeding in infancy, or maternal smoking during pregnancy, are factors influencing the risk of coronary disease.
Subject(s)
Arteriosclerosis/etiology , Breast Feeding , Smoking , Adolescent , Adult , Arteriosclerosis/pathology , Arteriosclerosis/prevention & control , Child , Child, Preschool , Coronary Vessels/pathology , Female , Humans , Male , Maternal-Fetal Exchange , PregnancyABSTRACT
A study of myocardial Mg, based on 1236 samples obtained at post-mortem examinations, is reported. There was a lower Mg level in samples from subjects certified to have died from IHD causes, by about 13%, than in samples from other deaths. There were lower levels, by about 5% where death had been lingering, compared to sudden, and there was a large range, equivalent to +/- 12%, in the mean Mg levels in samples from different areas. Various possible sources of bias are briefly considered.
Subject(s)
Coronary Disease/metabolism , Magnesium/analysis , Myocardium/analysis , HumansABSTRACT
In a study of myocardial magnesium and calcium levels in 1236 samples of heart muscle taken at necropsy in 28 centres in England and Wales, samples from patients who died from ischaemic heart disease had a mean Mg level 23 microgram/g lower and a mean Ca level 4 microgram/g higher than the mean for the total series after allowance had been made for a number of relevant factors. Mg levels were slightly higher and Ca levels slightly lower in sudden than in lingering deaths. There was no evidence of any association between the tissue levels and the levels of Mg or Ca in domestic tap-water, but there was a weak association between mean tissue Mg level and IHD mortality rates in the various towns.
Subject(s)
Calcium/analysis , Coronary Disease/metabolism , Death, Sudden , Magnesium/analysis , Myocardium/analysis , Adult , Aged , Coronary Disease/mortality , Coronary Disease/pathology , Humans , Middle Aged , Myocardium/pathologyABSTRACT
A lightning flash that struck the 150-meter weather tower at Kennedy Space Center was studied by several research groups using varioul techniques. The flash had unusually large peak currents and a stepped leader of relatively short duration. The charged regions neutralized by the three return strokes were located within a horizontal layer between heights of about 6 and 8 kilometers, where environmental temperatures were about -10 degrees to -20 degrees C. The charge source for the first return stroke coincided with a vertical shaft of precipitation inferred to have been graupel or hail. Charge sources for subsequent strokes were near the edge of the detectable precipitation echo. The overall channel length was about 10 kilometers. A Vertically oriented intracloud discharge occurred after the three return strokes.
ABSTRACT
The effects of lead, iron, copper, and zinc ions on delta-aminolevulinic acid dehydratase from red blood cell haemolysates in humans, both in the absence and presence of plasma proteins, have been investigated. delta-aminolevulinic acid dehydratase (ALAD) was not found to be a specific indicator of blood lead concentrations since it was also inhibited by copper and activated by zinc. Plasma protein protected the enzyme from both inhibition and activation. ALAD activity was found to be an indicator of the total metal ion concentration in the blood and was therefore considered to be of doubtful value in screening large populations for increased lead absorption.
Subject(s)
Copper/pharmacology , Hydro-Lyases/antagonists & inhibitors , Iron/pharmacology , Lead/pharmacology , Porphobilinogen Synthase/antagonists & inhibitors , Zinc/pharmacology , Blood Proteins/metabolism , Humans , Lead/blood , Lead Poisoning/enzymology , Porphobilinogen Synthase/bloodABSTRACT
In a study of the blood lead levels of 626 healthy blood donors no differences were found between men and women, but there was a significant increase with age. Resident donors had a higher blood lead than students, and the level in residents increased with living in the Aberystwyth area up to about 20 years. The levels in the students did not increase with residence in Aberystwyth. No differences were found in the blood lead of donors living in different wards of Aberystwyth and none between the blood lead of donors living in the rural area and those in the town. Almost half of the local resident donors had a level above the "normal" range.
