PubMed Health⌕ Search

Biomedical subjects

M L Fields

Publications and source records attributed to M L Fields.

At least 19 recordsLinked to original sources
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↗
PubMed1968

Growth and destruction of Salmonella typhimurium in egg white foam products cooked by microwaves.

Currently, in both home and institutional food preparation, attempts are being made to produce high quality foods with a minimum of time and effort. Research is being carried out to develop equipment capable of cooking foods in a fraction of the time required by conventional methods; as a result, the problem arises as to the bacteriological safety of these products. We investigated the microbiological aspects of lemon and chocolate foam pies before and after cooking by microwaves for less than 2 min. Pies prepared with sterile equipment under sanitary conditions were inoculated with washed cells from a 24-hr broth culture of Salmonella typhimurium and were incubated for 24, 48, and 72 hr at 33 C. The same procedures were followed in model systems to determine the effects of various sugar and pH levels on the survival of S. typhimurium. No S. typhimurium was detected in inoculated cooked or uncooked lemon pies by the plating method; with the Lactose Broth pre-enrichment method, survivors were detected in lemon pies immediately after preparation. After electronic cooking, no survivors were detected in lemon pies by plate counts, whereas cells were recovered from chocolate pies by the Lactose Broth method. Both chocolate and lemon pies had lower counts throughout the 72-hr incubation period than the model systems compared to them. With the model systems, at pH 7.3, media containing sugar inhibited the growth of S. typhimurium but did not cause a significant reduction in counts during the incubation times studied. At pH 3.7, media without sugar yielded no cells with the Lactose Broth pre-enrichment method after 48 hr of incubation, whereas media with sugar were not sterile until after 72 hr of incubation. Apparently, the presence of sugar in the medium had a protective influence which made the lethal effect of the low pH less severe.

Cooking↗