PubMed Health⌕ Search

Biomedical subjects

W I Manton

Publications and source records attributed to W I Manton.

26 records · Page 2Linked to original sources
PubMed1984

High accuracy (stable isotope dilution) measurements of lead in serum and cerebrospinal fluid.

The concentration of lead in blood, serum, cerebrospinal fluid, and urine was measured in patients with neurological disease and in control subjects including cases of plumbism. A plot of blood lead versus serum lead resembles the familiar curves of blood lead versus either free erythrocyte porphyrin or urinary delta-aminolaevulinic acid in that serum lead is constant up to a blood lead concentration of 40 micrograms/dl (2 mumol/l) and rises steeply thereafter. The serum lead concentrations yield renal clearances in the range 5-22 ml/min in agreement with values obtained with radiolead on man and predicted from animal studies. The lead content of cerebrospinal fluid is consistently less than that of serum, averaging 50% of the serum concentration for blood leads of less than 20 micrograms/dl (1 mumol/l) but rising to 80-90% in cases of plumbism. Patients with motor neurone disease could not be distinguished from those with other neurological diseases on the basis of the lead content of their serum or cerebrospinal fluid.

Humans↗
PubMed1983

Cytoarchitectonic distribution of zinc in the hippocampus of man and the rat.

Zinc was measured in whole hippocampus and in hippocampal sub-regions by stable-isotope dilution mass spectrometry. In both man and the rat, the most zinc (102-145 ppm, dry weight) was found in the hilar region, the least (27-35) in the fimbria. The amount of zinc directly associated with mossy-fiber axons was estimated to be approximately 8% of the total zinc in the hippocampus, and the concentration of mossy-fiber zinc was estimated at 220-300 microM. Methodological and theoretical implications of the quantitative findings were discussed.

Aged↗
PubMed1983

Distribution of lead in body fluids after ingestion of soft solder.

Blood, serum, cerebrospinal fluid, and urine obtained from a patient before and after chelation therapy showed that (1) the ratio of Pb in his cerebrospinal fluid to that in his serum varied from 0.4 to 0.9 and was independent of serum Pb concentration; (2) the fraction of Pb in his serum fell linearly with decreasing blood Pb concentration and changed from 1.6% to 0.33% as his blood Pb concentration changed from 116 micrograms/dl (5.6 mumol/l) to 31 micrograms/dl (1.5 mumol/l); and (3) his renal clearance of Pb from serum varied from 5 ml/min to 36 ml/min. This high value was obtained 11 days after chelation and is attributed to large quantities of Sn in his urine promoting the excretion of Pb. Solder was identified in his stool after discovery of radio-opaque material in his bowel. The Pb isotope ratios of the solder were different from those in his urine when he was first admitted, and showed that he had ingested solder when he had returned home on weekend passes.

Body Fluids↗
PubMed1982

Lead poisoning from retained bullets. Pathogenesis, diagnosis, and management.

Lead intoxication (plumbism) from retained bullets has rarely been reported but may be fatal if unrecognized. Bullets lodged within joint spaces or pseudocysts are more likely to develop this complication, although patients with retained missiles in other locations may also be at risk. Subtle findings such as the occurrence of unexplained anemia, abdominal colic, nephropathy, or neurologic deterioration in patients with retained missiles may suggest consideration of plumbism. An intercurrent metabolic stress such as infection, endocrinopathy, or alcoholism may be a precipitating factor. Among the various diagnostic studies available, mass spectrometric stable isotope dilution analysis may be the most reliable. It is important to employ chelation therapy prior to any operative intervention. This will reduce the mobilization of lead from bone during or following the surgical procedure.

Adult↗
PubMedDate not supplied

Sources of lead in blood. Identification by stable isotopes.

The isotope ratios of lead in the blood of ten subjects resident in Dallas, Texas, were measured from April 1974 to June 1975. During the same period, the ratios in the city's air changed linearly by 6%. One subject gave erratic results, but the remainder yielded ratios that changed systematically--some linearly, others cyclically with turning points occurring in August to October and February to April. Two South African subjects were 6 months out of phase with their U.S.-born wives and the other U.S.-born subjects. Since the South Africans are presumed to have in their skeletons lead that is isotopically distinct from that in the U.S. environment, the cycles are attributed to the mixing of skeletal and dietary lead. The dietary component is inferred to be greatest in August to October, which correlates with the time at which 25-hydroxyvitamin D is reported to have maximum concentration in blood. On the assumption that the isotope ratios of dietary leads remained constant, the proportion of airborne lead in the blood of those subjects whose ratios changed linearly could be calculated, and values between 7 +/- 3% and 41 +/- 3% were obtained.

Adult↗