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Biomedical subjects

J C McDonald

Publications and source records attributed to J C McDonald.

At least 19 recordsLinked to original sources
PubMed1992

Ferruginous body counts in sputum as an index of past exposure to mineral fibres.

Previous work by our group among vermiculite miners exposed to fibrous tremolite demonstrated that asbestos body counts in sputum closely reflected intensity and duration of past exposure. In the present project sputum samples from nearly 600 volunteers from 11 cohorts of workers exposed to asbestos and other mineral fibres were found to contain much lower numbers of asbestos bodies than had been observed in vermiculite workers and these counts did not reliably reflect past levels of exposure. No evidence was found that occupational exposure to man-made mineral fibres led to any ferruginous body formation. Asbestos body counts appeared to differentiate between mesothelioma cases and controls and between levels of radiological asbestosis, but in both comparisons, based on small numbers, the power of discrimination was low. Substantial variation was found both in asbestos body and in macrophage counts in daily sampling of vermiculite workers but it was not sufficient to invalidate comparison between groups for epidemiological study. In individual subjects, however, little reliance can be put on results from a single sputum sample, particularly if negative.

Adult↗
PubMed1992

Major vascular injuries of the torso.

We reviewed autopsy data from 802 trauma deaths in northwestern Louisiana from January 1983 to March 1988 and found that 18% of all such deaths involved noncardiac major vascular injuries of the torso. Ninety-four percent of all deaths from blunt trauma and 45% of all deaths from penetrating trauma involved injury to the aorta, either thoracic or abdominal. Injuries to the thoracic aorta accounted for 11% of all trauma-related deaths in northwestern Louisiana; 68% of all victims died at the scene of the trauma. During this period 57 patients with noncardiac major vascular injuries of the torso were treated at the LSU-Shreveport Medical Center. Fifteen (26%) of these patients were transported to LSU-SMC from neighboring rural parishes outside the Shreveport-Bossier City metropolitan area. The mortality was 37%, and there was no difference in survival between those patients transported to LSU-SMC from within the Shreveport-Bossier City area and those transported from the rural parishes. Multivariate analysis of data showed that survival was determined by the complexity of the injury, the patient's ability to reach the hospital, and the stability of the patient's condition on arrival at the hospital. Transport time did not appear to affect survival.

Adult↗
PubMed1992

HLA in human serum--quantitation of class I by enzyme immunoassay.

A solid-phase, enzyme-linked immunoassay was used to quantitate the soluble fraction of HLA-class I. The sera of 318 individuals were studied, as well as the urine of six individuals with normal renal function. The stability of blood concentrations of the soluble HLA was also evaluated. The data justify the following six conclusions. (1) All normal people have circulating HLA (mean = 357 ng/ml). (2) The population can be divided into one group of low secretors (mean = 162.4 +/- 65.2 ng/ml) and another group of high secretors (mean = 540.7 +/- 185.9 ng/ml) (P less than 0.01). (3) Blood levels in each individual are reasonably consistent over short (days) and long (years) periods of time. (4) The mean concentration of soluble HLA-class I in all renal failure patients was 590 ng/ml, significantly higher than normal (P = less than 0.05); it was highest in patients on peritoneal dialysis (mean = 683 ng/ml) in spite of substantial chronic loss in peritoneal dialysate. (5) Renal allograft recipients with stable allograft function also had mean values greater than normal at 554 ng/ml (P less than 0.05). (6) Soluble HLA-class I was not detected in the urine of individuals with normal renal function.

Enzymes, Immobilized↗
PubMed1992

Organic brain damage and occupational solvent exposure.

Three hundred and nine men with organic dementia, cerebral atrophy, or psycho-organic syndrome admitted for five nights or more to one of 18 Quebec hospitals were individually matched with patients admitted (1) with some other psychiatric diagnosis and (2) to a general hospital. Lifetime occupational histories were obtained by telephone. Occupational exposure to solvents was assessed blind to type of case by (1) individual ratings and (2) a job exposure matrix; men who worked in moderate or high solvent concentrations for at least 10 years were considered exposed. With the psychiatric referent series, an odds ratio of 1.4 (90% CI 1.0-2.0) was calculated by individual exposure ratings and 1.4 (90% CI 0.9-2.2) by job matrix. Increased risk was mainly in those with organic dementia or cerebral atrophy and an alcohol related diagnosis. The same pattern of risk was found against the general hospital referents. Adjustment for possible confounders did not alter the risk estimates appreciably. Also, lifetime job histories, compared in selected case-referent pairs, gave similar evidence of increased risk (odds ratio 2.3; 90% CI 1.0-5.5). It is concluded that the combined effect of occupational solvent exposure and alcohol intake is probably an important cause of organic brain damage.

Adult↗
PubMed1992

Psychiatric disorders and occupational exposure to solvents.

Three hundred and eighty one men admitted to hospital for the first time with any psychiatric diagnosis were individually matched for age and year to patients admitted to general hospitals. An occupational history was obtained from 90% of this study group by telephone interview or mail. Exposure to solvents was assessed by three methods, individual rating of each job recorded, application of an exposure matrix based on job title, and assessment of lifetime job histories of selected case-referent pairs. A sample of individual ratings used in the analysis was compared with ratings made by five experts. The panel values tended to be lower but all six sets of ratings correlated well. There was no increased risk of psychiatric illness among subjects exposed to moderate or greater solvent concentrations for at least 10 years (odds ratio (OR) 1.0, 90% confidence interval (90% CI) 0.7-1.4, individual rating; OR 1.1, 90% CI 0.6-2.0, job title matrix; OR 0.9, 90% CI 0.5-1.7, lifetime assessments). At higher exposures the risk was increased--although not to a statistically significant degree--especially for cases with non-psychotic diagnoses (ICD-9 codes 300-316). This negative result, by all three methods of assessment of exposure, contrasted with that from a parallel investigation of cases of organic psychoses and cerebral degeneration.

Adult↗
PubMed1992

Preoperative management of sickle cell patients.

During a 12-year period, 59 patients with sickle cell disease underwent a total of 73 operative procedures. There was a total of 30 non-sickle-cell-related and 7 sickle-cell-related complications for an incidence of 41% and 10% respectively. There were no deaths. When complications were compared between patients that were transfused and those not transfused, there was no difference in the incidence of sickle-cell-related complications with an 8% incidence for the non-transfused group and 10% for the transfused group. A higher incidence of non-sickle-cell-related complications (46% versus 32%) was noted in the transfused group, with atelectasis being the most common complication (p = .29). The type of transfusion therapy did not influence morbidity, since the complication rates in the simple and exchange transfusion groups were similar. In conclusion, our data indicate that routine preoperative blood transfusion does not appear to be beneficial in the surgical sickle cell patient, since preoperative blood transfusions did not reduce the incidence of sickle-cell-related complications.

Adult↗
PubMed1979

External ureteroneocystostomy and ureteroureterostomy in renal transplantation.

"External" ureteroneocystostomy is a method of reconstructing the urinary tract for renal transplantation. As performed by us, it is a modification of the technique of Witzel, Sampson, and Lich. It has the advantages of requiring a very short length of ureter, avoiding a separate and large cystotomy, and retaining the antireflux mechanism. This technique is described in detail. Ureteroureterostomy has been used as the preferred procedure when the bladder wall is very thin or when the vascular attachments are such that a ureteral length of greater than 6-7 cm would be required for bladder implantation. Since using these techniques we have reduced the early complication rate of ureteral implantation from 11.9% in a consecutive series of 126 transplants to 0% in the last 88 consecutive transplants. A review of the literature which led to the adoption of these techniques is also presented.

Humans↗
PubMed1978

Arteriovenous fistulas for long-term dialysis. Factors that influence fistula survival.

We reviewed our total experience with arteriovenous (AV) fistulas for long-term hemodialysis. We are unable to show any significant difference in the survival of AV fistulas based either on the type of material used to create the fistulas or on their location. Complications encountered early in this experience largely were due to technical or judgmental errors. Thrombosis of radiocephalic fistulas resulted from failure to use a vein of adequate caliber. Failure of bovine artery heterograft AV fistulas resulted either from wound infection or from the use of a diseased artery that was incapable of delivering sufficient blood to keep the fistula open. Infection around a heterograft fistula frequently was associated with a lymphocele. The meticulous division, between clips or ligatures, of all tissues deep to the skin prevented lymphocele formation.

Adolescent↗
PubMed1978

Malignant cystosarcoma phylloides. Treatment and prognosis.

Twenty-six cases of malignant cystosarcoma phylloides treated at The Charity Hospital of Louisiana were reviewed. No metastases to axillary lymph nodes was observed. The lesion appears to metastasize seldom, if ever, to lymphatics, and axillary dissection is seldom required. Local recurrence was common, however, and justifies wide resection of the primary. Mortality was related more to the size of the lesion than to other findings such as skin or muscle involvement. No lesion with less than three mitoses per ten high power fields and minimal stromal atypia proved fatal. Associated neoplasia was common, particularly in the opposite breast.

Adult↗
PubMed1978

Mesothelioma after crocidolite exposure during gas mask manufacture.

Of 199 persons employed in the manufacture and handling of Canadian military gas mask canisters containing pure crocidolite, 1939 to 1942, by the end of 1975, 56 had died, 120 were still alive, and 23 could not be traced. Nine (16%) of the deaths were probably due to malignant mesothelioma, six involving the peritoneum. The risk of mesothelioma after crocidolite exposure appears to be many times greater than that after chrysotile.

Asbestos↗
PubMed1978

A heterophile system in human renal transplantation. VII. The antigen is an intrinsic component of several human tissues.

The presence or absence of the heterophile transplantation antigen was sought in renal tissue from stillborn infants, primary cell cultures, and several organs from adult human cadavers. The heterophile transplantation antigen was found in renal tissue at birth, was retained in human renal cell culture, and was present in human organs other than kidney. The most likely explanation for these results is that the heterophile transplantation antigen is an intrinsic component of many human tissues.

Cells, Cultured↗
PubMed1978

Mortality after long exposure to cummingtonite-grunerite.

Ore containing cummingtonite-grunerite has been mined to extract gold since 1876 in Lead, South Dakota. Each of the 1,321 men who were recorded as having worked 21 years or more with the Homestake Mine was allocated to one of 5 dust-exposure categories on the basis of work history and available information on environmental conditions. All except 9 men were traced to the end of 1973, when 652 were still living; the cause of death was ascertained for 657 of the 660 men who had died. Deaths from cerebrovascular accidents and malignant disease were close to the numbers expected and from accidents and other causes were fewer than expected, but in each of the 3 diagnostic groups--pneumoconiosis (mainly silicosis), tuberculosis, and heart disease--there were more than 30 excess deaths. A clear dust-exposure relationship was found for pneumoconiosis and respiratory tuberculosis--with relative risks for the 2 groups with greatest exposure to dust as compared to the 2 with least exposure, of 19.9 and 16.0, respectively, but there was no convincing evidence of an increase in respiratory cancer.

Adolescent↗