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J B Lawrence

Publications and source records attributed to J B Lawrence.

98 records · Page 6Linked to original sources
PubMed1982

Adenoid cystic carcinoma: a comparative pathologic study of tumors in salivary gland, breast, lung, and cervix.

Histologic, histochemical, and ultrastructural features of eight adenoid cystic carcinomas arising at diverse sites were compared in order to determine diagnostic values and to investigate histogenetic mechanisms. These tumors originated in the salivary glands, breast, uterine cervix, and tracheobronchial tree. By light microscopy each tumor was seen to have morphologic features of adenoid cystic carcinoma, yet only five of the eight cases showed differential staining for the two mucin types, stromal and epithelial, which are reportedly present in these tumors. In contrast, every case showed a set of fine structural features which, in aggregate, are specific for adenoid cystic carcinoma. These features include pseudocysts, intercellular spaces, basal lamina, and true glandular lumens. The most prominent feature is the pseudocyst, which mimics a glandular lumen by light microscopy but is actually a rounded extracellular space containing basal lamina. Ultrastructurally, the variation in composition of the extracellular compartments, including pseudocysts and true lumens, appears to explain the lack of uniformity in the histochemical staining. The tumors also contained cytoplasmic microfilaments in parallel bundles, consistent with myofilaments. The presence of these filaments combined with basal lamina suggests myoepithelial differentiation, yet it is not known whether these tumors truly originate from myoepithelium or show differentiation toward myoepithelium as a part of the neoplastic process. Regardless of their histogenesis, this study shows that true adenoid cystic carcinomas do arise in different organs. Knowledge of the specific ultrastructural features of adenoid cystic carcinomas can be useful in classifying these tumors in some cases.

Adult↗
PubMed1981

Sudden death associated with thyroid hormone abuse.

Three patients with hyperthyroidism due to deliberate intake of excessive amounts of L-thyroxine are described wherein death was "instantaneous" and presumably due to ventricular fibrillation. Hyperthyroidism was not recognized on admission in two of these patients because of atypical presentations. Autopsy was performed in two patients. In one patient no coronary disease was present and focal myocarditis with leukocytic infiltration was noted. The second patient had an acute posterior myocardial infarction due to acute coronary thrombosis, but focal areas of leukocytic infiltration and fibrosis were also seen in the anterior wall not involved in the process of infarction. Factitious hyperthyroidism due to L-thyroxine abuse can be associated with sudden death in the absence of coronary artery disease and may be related to a drug induced myocarditis.

Adult↗
PubMed1981

Induction by butyrate of differentiated properties in cloned murine rhabdomyosarcoma cells.

A cell line derived from the murine rhabdomyosarcoma BW10139 (Dexter, Cancer Res. 37: 3136, 1977) was subcloned and examined with respect to growth and myogenic characteristics in the presence and absence of 1 mM butyrate. Without butyrate, these cells behave as typical transformed cells: they grow rapidly and chaotically, do not form multinucleated muscle fibers and have little or no creatine kinase activity. In the presence of 1 mM sodium butyrate or butyric acid, growth slows, cells become arranged in whorl patterns, and creatine kinase activities increase to levels comparable to those found in normal chick myoblasts immediately prior to cell fusion. The increase in creatine kinase activity is detectable within 2 h exposure to butyrate, reaches a maximum by 24 h, and the elevated level can be maintained for at least six weeks. The induction is reversible upon sequential addition, deletion, and readdition of butyrate to the culture medium. Isoenzyme analyses demonstrated that only the BB form of creatine kinase is induced; MM creatine kinase was not detected. Although formation of multinucleated cells increases after exposure to butyrate, no typical myotubes form. The results suggest that this rhabdomyosarcoma cell line can, under appropriate conditions, re-express some properties characteristic of skeletal muscle, but not the complete muscle phenotype.

Animals↗
PubMed1978

Presence of human chromosome 21 alone is sufficient for hybrid cell sensitivity to human interferon.

Human/mouse somatic cell hybrids with chromosome 21 as the only detectable human genetic material were sensitive to both human leukocyte and fibroblast interferons. The presence of additional human chromosomes decreased the amount of interferon needed to attain a given level of virus resistance. Decreased cytopathic effects, decreased virus yields, and the appearance of a specific phosphorylated protein associated with interferon treatment were all observed in hybrids maintaining only human chromosome 21. The phosphorylated protein found in extracts of these human interferon-treated hybrid cells was of mouse origin.

Animals↗
PubMedDate not supplied

Vascular sarcoidosis: a rare cause of pulmonary hypertension.

Pulmonary hypertension is an uncommon complication of sarcoidosis and is usually related to the development of end-stage, interstitial fibrosis or honeycomb lung. We describe a patient with sarcoidosis who developed pulmonary hypertension in the absence of significant parenchymal fibrosis. The pulmonary hypertension in this case was caused by granulomatous destruction of arteries and veins, as documented by an open-lung biopsy and autopsy. Clinical features, including pulmonary function tests, are presented which suggested that end-stage interstitial lung disease was not causing the hypertension. Recognition of this complication of sarcoidosis is important if effective therapy is to be found.

Adult↗