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Biomedical subjects

L J Williams

Publications and source records attributed to L J Williams.

72 records · Page 4Linked to original sources
PubMed1977

Calibration methods for automated hematology instruments.

Recent CAP survey data have documented marked improvement in the reproducibility of hematologic tests. The favorable outcome is attributable largely to the widespread use of automated whole-blood analyzers. Calibration variability, however, detracts from this enhanced precision, and there are clear indications that improvement is necessary. Primary calibration methods for hemoglobin, hematocrit and cell counting procedures are presented. The methods of applying these primary calibration methods to automated whole-blood analyzers are delineated. The use of both preserved reference blood and statistical control technics for the identification of calibration loss is described.

Automation↗
PubMed1976

Human neoplastic and normal cells in tissue culture. I. Cell lines derived from malignant melanomas and normal melanocytes.

Forty-six cell lines derived from 31 human melanomas obtained from 28 patients were cultured. Fourteen of 16 lines have produced malignant tumors when injected into nude (thymus-deficient) mice. Tumors in 5 of the nude mice metastasized to distant lymph nodes and/or to the lungs of the mouse host. Extreme variability from line to line was observed for doubling time (34 to 106 hr), plating efficiency (0-86%), and melanin production. All tested lines had type B glucose-6-phosphate dehydrogenase, thereby excluding HeLa cell contamination. HeLa cells have been grown for some time in our laboratory. Our results clearly demonstrated that HeLa cell contamination does not occur invariably in heteroploid lines growing in a laboratory simultaneously with Hela cells, provided that proper care is taken to avoid such occurrence. Multiple cell lines derived from the same tumor had identical phosphoglucomutase enzyme phenotype, which suggested a lack of significant cross-contamination between the lines. Four long-term cultures of normal human uveal embryo melanocytes have also been established and characterized. Although all produced melanin after reaching saturation density, they differed from the melanoma cells morphologically; they were flat, not refringent, and lacked piling up and plating ability. When melanoma cells were exposed to bromodeoxyuridine (BUDR) for long periods, a phenotypic change toward non-neoplastic characteristics was observed. Cells became flat and not refringent and, when injected into nude mice, tumors appeared after a long latent period. These changes were completely reversible in vitro and in vivo. The BUDR-treated cultures were undistinguishable from the untreated mother cultures after 2 to 3 passages. Lines derived from tumors in nude mice (obtained by injection of BUDR-treated cells) were again indistinguishable from the untreated mother line. Normal melanocytes were mostly euploid; all the melanoma cells were aneuploid. All 29 cell lines derived from 14 patients had an average chromosome number higher than 46. Detailed group-by-group chromosome analysis always showed an excess of C chromosomes, which suggested that hyperreduplication of one or more C chromosomes is a specific characteristic of human melanomas.

Adult↗
PubMed1975

Ultrastructure of the lung in Loeffler's pneumonia.

A case is presented fulfilling the diagnostic criteria of "Loeffler's eosinophilic pneumonia". No etiologic factors could be determined, and the chest roentgenogram returned to normal. Lung biopsy at the peak of the disease demonstrated an interstitial eosinophilic pneumonia without tissue necrosia or vasculitis. By electron microscopy, the alveolar capillary basement membranes were intact and exhibited no immune deposits. Normal appearing eosinophils were abundant in the alveolar capillaries, interstitium and alveolar spaces. Occasional eosinophils released their granules within the alveolar wall. Macrophages were increased in number in both the alveolar wall and alveolar spaces.

Biopsy↗
PubMed1969

Housing.

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Agriculture↗
PubMedDate not supplied

An autologous fibrinogen-based adhesive for use in otologic surgery.

Successful middle ear surgery requires the availability of a safe, effective bonding material. Side effects caused by synthetic materials have led to the use of biologic adhesives; however, they carry the risk of transmission of infectious disease if they are prepared from pooled human blood. A procedure for the production of an autologous fibrinogen-based adhesive using polyethylene glycol to precipitate the fibrinogen-factor XIII component from plasma is described. This procedure requires 40 ml of whole blood and approximately 3 hours' preparation time, and it can be performed in any blood bank with the facilities for sterile techniques. This adhesive has been used successfully for otologic surgery in 12 patients, and further study of the use of this biologic adhesive for other microsurgical techniques should be undertaken.

Blood Transfusion, Autologous↗
PubMedDate not supplied

Comparison of 5'-nucleotidase activities among cultured murine melanoma cell lines.

The activity of 5'-nucleotidase and ouabain-sensitive Na/K ATPase was determined in seven different mouse melanoma cell lines. Ouabain-sensitive Na/K ATPase activity was found in NP40-treated cell homogenates of all cell lines. However, 5'-nucleotidase activity was found in only one mouse melanoma cell line--JB/RH. The absence of expression of 5'-nucleotidase activity in the other six cell lines is not associated with pigmentation in melanoma cells, nor is the gene switched off in all transformed melanocytes of C57BL/6 origin.

5'-Nucleotidase↗