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Biomedical subjects

M L Fields

Publications and source records attributed to M L Fields.

At least 19 recordsLinked to original sources
PubMed2001

Fas/Fas ligand deficiency results in altered localization of anti-double-stranded DNA B cells and dendritic cells.

Autoantibodies directed against dsDNA are found in patients with systemic lupus erythematosus as well as in mice functionally deficient in either Fas or Fas ligand (FasL) (lpr/lpr or gld/gld mice). Previously, an IgH chain transgene has been used to track anti-dsDNA B cells in both nonautoimmune BALB/c mice, in which autoreactive B cells are held in check, and MRL-lpr/lpr mice, in which autoantibodies are produced. In this study, we have isolated the Fas/FasL mutations away from the autoimmune-prone MRL background, and we show that anti-dsDNA B cells in Fas/FasL-deficient BALB/c mice are no longer follicularly excluded, and they produce autoantibodies. Strikingly, this is accompanied by alterations in the frequency and localization of dendritic cells as well as a global increase in CD4 T cell activation. Notably, as opposed to MRL-lpr/lpr mice, BALB-lpr/lpr mice show no appreciable kidney pathology. Thus, while some aspects of autoimmune pathology (e.g., nephritis) rely on the interaction of the MRL background with the lpr mutation, mutations in Fas/FasL alone are sufficient to alter the fate of anti-dsDNA B cells, dendritic cells, and T cells.

Animals↗
PubMed1985

Frequency of illness associated with epidemic hepatitis A virus infections in adults.

Hepatitis A virus infection is often described as mild or asymptomatic, particularly in children. The failure of most adults who are found to be immune to remember symptoms of an illness suggestive of hepatitis A virus supports this belief. In 1982, two large outbreaks occurred in well documented populations of military personnel. These outbreaks were each extensively studied epidemiologically and serologically. It was found that 28/29 (96.6%) hepatitis A infections recognized prior to immune serum globulin in Outbreak A and 35/46 (76.1%) infections in Outbreak A were symptomatic. Symptomatic cases failed to occur beyond eight days of immune serum globulin administration to these predominantly susceptible groups. Between 40 and 70% of patients were icteric. Apparent contrasts in symptoms associated with hepatitis A infection in adults and children suggest a basic age-dependent difference in immune response to such infection.

Adolescent↗
PubMed1984

Toxic effects of fermented and unfermented sorghum meal diets naturally contaminated with mycotoxins.

Male weanling rats fed diets containing fermented and unfermented tannin-free sorghum meals naturally contaminated with traces of ochratoxin A, zearalenone, and an unidentified toxic substance developed anorexia. Mean changes in body weight over a 28-day feeding period for rats fed fermented and unfermented sorghum meal and ANCR casein diets of 8% protein were -2.8, +13.8, and +100.5 g, respectively. Rats fed fermented sorghum meal developed alopecia; hematological findings showed a decreased mean corpuscular volume, hypochromic microcytosis, balanced leukopenia, and hypoproteinuria . Histological findings showed testicular hypoplasia of the germinal epithelium and no mature spermatozoa. Necrosis and mineralization in Henle's loop were also observed. No damage was apparent to the liver, cerebellum, cerebrum, spleen, or adrenal glands.

Animal Feed↗
PubMed1977

Cushing's syndrome associated with bronchial adenoma.

A case of Cushing's syndrome associated with a bronchial adenoma treated eight years before with bilateral adrenalectomy was cured by surgical excision of the bronchial adenoma. A discussion of clinical and hormonal features of this lesion is presented. It is concluded that this tumor manifested a capability of synthesizing and releasing substances which are chemically and biologically similar to adrenocorticotropic hormone andmelanocyte-stimulating hormone (MSH). Stimulation of the adrenal cortex by this material results in hyperplasia and hypersecretion, and stimulation of the melanocytesy MSH resulted in excessive pigmentation. Acknowledgment: We are indebted to Doctors Wendell Nicholson, David N. Orth, and Grant W. Liddle of Vanderbilt University for determinations of ACTH and MSH levels and to Mrs. E.P. Jessup for assistance in preparation of statistical data for this manuscript.

Adenoma↗
PubMed1974

Bacillus stearothermophilus in soils of Iceland.

Bacillus stearothermophilus was found in Icelandic soils. Of the 33 strains studied, only four grew at 25 C. Temperatures as high as 27 C in bare soil at a depth of 1 to 1.5 cm were measured at the collection site. However, to demonstrate growth the cultures had to be incubated for 3 weeks, and soil temperatures remained at 27 C only for shorter periods of time.

Aerobiosis↗
PubMed1972

Studies on variants of Bacillus stearothermophilus strain NCA 1518.

The heat resistance, fermentation reactions, nutritional requirements, and phage sensitivity of 18 selected morphological variants of Bacillus stearothermophilus NCA 1518 were studied. It was found that when smooth variants mutated to rough colonial morphology, there was no concurrent change in fermentation reactions, nutritional requirements, or heat resistance. The smooth variant, and the rough mutants derived directly from it, presented a uniform pattern of biochemical capabilities which differed from the pattern presented by the rough variants isolated from the same stock culture. This led to the conclusion that the smooth and rough types previously observed in stocks of B. stearothermophilus NCA 1518 either were carried in the stock since the original isolation or represent a very profound and uncommon mutation, or that one of the variants has been introduced into the stock culture from an extraneous source sometime in the past.

Bacillus↗