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Biomedical subjects

J J Chisolm

Publications and source records attributed to J J Chisolm.

At least 37 records · Page 2Linked to original sources
PubMed1990

Health and environmental outcomes of traditional and modified practices for abatement of residential lead-based paint.

We evaluated traditional and modified practices for abating lead-based paint in homes of children with blood-lead concentrations (PbB) greater than 1.4 mumol/L (greater than 29 micrograms/dl). Traditional abatement resulted in acute increases in: 1) lead contaminated house dust (generally 3 to 6-fold over pre-abatement levels, but at abated sites typically 10 to 100-fold); and 2) the PbBs of nearly half of the occupant children. Modified practices represented modest short-term improvement compared to traditional practices but were also inadequate. By six months, it was clear that neither form of abatement resulted in long-term reductions of PbB or house dust lead levels, leaving children at continued risk of excessive exposure to lead and permanent adverse neurobehavioral effects. Windows were found to be high sources of lead contaminated house dust. Recommendations are made for improved abatement practices including more complete abatement of window units and more effective clean-up to remove lead-bearing dust. Thirteen million US children live in lead-painted dwellings. Research is needed to identify abatement strategies that will be practical and well suited to the current understanding of low-level lead toxicity.

Child↗
PubMed1987

Toxic lead exposure in the urban rock dove.

Thirteen adult urban rock doves (Columba livia), 12 captured alive and one found dead, were studied from the Baltimore zoo. The mean concentration of lead in the blood for the 12 live birds was 184.5 +/- 531.2 (range 10.5-1,870 micrograms/dl). Three of the 13 birds with high measured blood and tissue lead concentrations were found at necropsy with lead shot pellets in their gizzards. Correlations were not found between concentrations of lead in the blood and body weight or hematocrit. Conversely, high correlations were noted between concentrations of lead in the blood and measured liver and kidney concentrations (r = 0.946, P less than 0.01; r = 0.993, P less than 0.01, respectively). Numbers of intranuclear acid-fast inclusions per 10 consecutive fields (100x oil immersion lens) correlated well with measured kidney lead concentrations (r = 0.990, P less than 0.001).

Animals↗
PubMed1986

Lead toxicity masquerading as sickle cell crisis.

We recently saw a 12-year-old black boy with known sickle cell disease who had been seen many times for abdominal pain thought to be secondary to a vasoocclusive crisis. The patient eventually was admitted, after a seizure and the onset of obtundation. The etiology of his acute encephalopathy remained unclear until bone films of his knees fortuitously revealed "lead lines." The patient was treated and did well subsequently. This case emphasizes the importance of considering other diagnoses when a sickle cell patient presents with a crisis.

Anemia, Sickle Cell↗
PubMed1986

Lead exposure in an "urban" peregrine falcon and its avian prey.

Necropsy of a 7-yr-resident peregrine falcon (Falco peregrinis) from Baltimore showed a Pseudomonas infection involving the pharynx as the immediate cause of death. Concentrations of lead in liver and kidney measured 0.74 and 1.40 ppm, respectively. A survey of lead exposure was performed on 40 urban rock doves (Columbia livia). Thirteen additional rock doves were collected from sites removed from lead contamination and served as controls. The mean concentration of lead in the blood of the urban rock doves was 0.96 ppm (range 0.29-17.0 ppm) compared to 0.05 ppm (0.01-0.07 ppm) for control birds. Ninety-eight percent (39/40) of the urban rock doves had elevated concentrations of lead in their blood, while 27% (11/40) had sublethal concentrations. None of the control birds had increased concentrations of lead in their blood. Concentrations of lead in liver and kidney of 13 urban rock doves were 3.48 ppm and 9.53 ppm, respectively, compared to concentrations of 0.43 ppm and 0.50 ppm for four control rock doves. From these data a mean total concentration of lead per rock dove was calculated at 4.60 ppm for urban birds and 0.33 ppm for control birds.

Animals↗
PubMed1985

The relationship between the level of lead absorption in children and the age, type, and condition of housing.

A group of 184 preschool-aged children with pretreatment blood lead concentrations (PbB) greater than or equal to 50 micrograms/dl, who received inpatient chelation therapy, were followed prospectively as outpatients for 12 months after discharge. Of these, 160 were followed for 24-30 months. Serial PbB data were analyzed according to the type of housing to which each child was discharged. Following therapy, PbB stabilized by 3 months. Thereafter, highly significant differences (P less than 0.001) existed between those living in or visiting old houses in which lead-in-paint hazards had been abated according to local ordinances (m PbB = 38.5 micrograms/dl) and those discharged to "lead-free" public housing (m PbB = 28.8 micrograms/dl) or to recently, totally gutted and renovated old housing (m PbB = 28.7 micrograms/dl). During the period of study (1978-1982), no downward trend in PbB within housing groups was found during the first 12 months of follow-up. Of the 152 children discharged to old housing, 75 had 127 recurrences of PbB greater than or equal to 50 micrograms/dl. This emphasizes the need for close and prolonged follow-up in all cases. These data indicate that substantially improved methods of detection, classification, and abatement of lead hazards must replace traditional methods if lead exposure for young children in old housing is to be reduced to an acceptable level.

Child↗
PubMed1985

Erythrocyte porphobilinogen synthase activity as an indicator of lead exposure in children.

The European standardized method for measuring porphobilinogen synthase (PBGS, EC 4.2.1.24) activity in peripheral erythrocytes is widely used in epidemiological studies of low-level Pb absorption. We have modified it to include activation with dithiothreitol (DTT). In children with concentrations of Pb in whole blood ranging from 0.29 to 1.93 mumol/L, we found the following statistically significant correlations (r): blood Pb vs nonactivated PBGS activity = -0.773 (p less than 0.005); blood Pb vs DTT-activated PBGS activity = -0.265 (p less than 0.005); blood Pb vs the ratio of DTT-activated/nonactivated PBGS activity = +0.818 (p less than 0.005). At a DTT-activated/nonactivated PBGS activity ratio of 1, which indicates no Pb-dependent inhibition of PBGS, a corresponding blood Pb concentration of 0.24 mumol/L (50 micrograms/L) would be predicted. In individuals with hematological disorders, the DTT-activated/nonactivated ratio better predicted blood concentration of Pb than did the nonactivated PBGS activity, and largely compensated for the high variability in PBGS activity. We also describe techniques to minimize contamination by Zn and Pb and to stabilize enzyme activity during collection, transport, storage, and analysis of samples.

Adolescent↗
PubMed1985

Use of 2,3-dimercaptopropane-1-sulfonate in treatment of lead poisoning in children.

2,3-Dimercaptopropane-1-sulfonate (DMPS) is a water-soluble metal complexing agent. Administration to lead-poisoned children of 5-day courses of 200 or 400 mg of DMPS per m2 surface area per day given p.o. in divided doses resulted in a significant decline in the concentration of lead in blood. DMPS treatment did not significantly alter the concentrations of zinc or copper in plasma. Urinary excretion of lead, zinc and copper was increased by DMPS administration and these increases were sustained throughout the 5-day course of treatment. No significant changes in hepatic, renal or hematological function were found in DMPS-treated children and no side effects attributable to DMPS were noted. It is concluded that a 5-day course of DMPS given p.o. may be safe and effective in the treatment of asymptomatic lead poisoning in children.

Aspartate Aminotransferases↗
PubMed1984

The continuing hazard of lead exposure and its effects in children.

Recent epidemiological data have shown in U.S. children aged six months to five years, that an estimated four percent, or approximately 675,000 children, have increased lead absorption (i.e., blood lead concentration (PbB) greater than or equal to 30 micrograms Pb/dl (microgram%) whole blood). The rate was highest among low income, inner city black children, among whom 18.6% or approximately 159,000 show PbB greater than or equal to 30 micrograms%. There have been substantial reductions in the use of lead in gasoline and in lead in food during the past four years. Although the use of lead in residential paints was banned in the U.S. in 1977, a large stock of lead painted old housing remains in use today. Until this substandard old housing is completely renovated or replaced, it will remain the principle environmental lead hazard for young children. Regarding effects of lead in the CNS, there is agreement on the following: 1) sustained PbB greater than or equal to 60 micrograms% during the early preschool years substantially increases the risk of later learning impairment in school, 2) sustained PbB greater than or equal to 40 micrograms% may increase the risk significantly but moderately, 3) the clinical significance of sustained PbB during early childhood in the range of 25-40 micrograms% remains uncertain, and 4) prospective longitudinal studies are essential to delineate the CNS effects of low level lead exposure. The primary screening test for increased lead absorption is the free erythrocyte protoporphyrin (FEP) micro test. This test will detect 95% or more of children with PbB greater than or equal to 50 micrograms%; however, less than 50% are detected by the FEP test when PbB = 30-50 micrograms%.

Black or African American↗
PubMed1981

Erythrocyte protoporphyrin levels in Aotus trivirgatus.

High levels of the heme precursor, protoporphyrin, were found in a sample of 36 Aotus trivirgatus. The owl monkeys were of five different karyotypes and from three separate colonies. In many animals, a significant proportion of the protoporphyrin was not bound to zinc, as is normal, but existed as the free base protoporphyrin IX. The protoporphyrinemia may be related to major pathologies of captive Aotus.

Anemia, Hemolytic↗