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Biomedical subjects

A A Johnson

Publications and source records attributed to A A Johnson.

52 records · Page 3Linked to original sources
PubMed1992

Simultaneous determination of lactulose and mannitol in urine of burn patients by gas-liquid chromatography.

Ratios of lactulose/mannitol excretion in urine have been used to assess the extent of intestinal permeability in various disease and trauma conditions. Reported studies have used this technique to correlate altered gastrointestinal mucosal permeability to translocation of bacteria and endotoxin, leading to occult sepsis in burn patients. Enzymatic methods of analysis for urine concentrations of mannitol and lactulose were used in these studies. We have found that urine from patients with severe burns frequently contains compounds that interfere with the enzymatic methods. We describe using gas-liquid chromatography to determine mannitol and lactulose simultaneously in the urine of burn patients. To avoid the multiple peaks for the anomeric forms of the reducing sugars during precolumn trimethylsilyl derivatization, we converted the sugars to oximes before the silylation step. The method gave good recoveries of mannitol and lactulose added to burn patients' urine samples. Unlike the enzymatic methods, gas-liquid chromatography eliminates the effect of interfering compounds and allows for the simultaneous determination of both sugars in urine samples.

Burns↗
PubMed1990

An epidemic of Oroya fever in the Peruvian Andes.

Between February and October 1987, a febrile illness killed 14 persons and seriously affected at least 14 others in Shumpillan, a remote Peruvian mountain village of 353 people. The illness was characterized by fever, headache, chills, and pallor. The fatality rate of untreated cases was 88%. The patients, 71% of whom were male, were 1-75 years of age. Fatal illnesses progressed from lethargy to coma to death in 3-60 days. Patients treated empirically with chloramphenicol survived. Bartonella bacilliformis was isolated from the whole blood of 3 patients. A serologic study revealed a high prevalence of antibodies to B. bacilliformis in the villagers. It is concluded that the villagers suffered from an epidemic of Oroya fever.

Adolescent↗
PubMed1985

A new nutrient index for measuring nutritional well-being of Indian states.

A composite nutrient index was computed for ten states of India by using principal component analysis based on the average intake of eight nutrients, namely protein, calories, iron, vitamin A, thiamin, riboflavin, niacin and vitamin C. The new nutrient index is significant from a nutritional point of view in a community or a country. Two factors from the list of eight variables and the matrix of factor loadings after making orthogonal rotation have been extracted and named as the Energy Factor and the Vitamin Factor. The PQLI was computed for ten Indian States and a rank correlation of the nutrient index and PQLI was computed. The rank correlation was not significant. A negative significant regression coefficient of the value of food consumption with the nutrient index was found in the regression equation. Further statistical analysis of the energy factor with independent variables reconfirmed a very high negative relationship between the GINI Coefficient and the degree of literacy. The higher the literacy levels the lower were the intake of nutrients.

Diet↗
PubMed1982

The prevalence and the etiology of the nutritional anemias in Guyana.

A survey was carried out in Guyana to determine the prevalence and the etiology of the nutritional anemias among both sexes, in various age groups, and in pregnant and lactating women. The sample consisted of 590 subjects drawn from 103 households selected by multistage cluster sampling. Anthropometric and hematological measurements and stool investigations for intestinal parasites were carried out in each subject. Socioeconomic and other demographic data were obtained for each household. High prevalences of anemia, although of a relatively mild degree, were found among all age groups especially among pregnant and lactating women. The major factors related to Hb levels were found to be inadequate consumption of food rich in the erythropoietic nutrients, iron deficiency, age, sex, pregnancy, household income, and percentage of household income spent on food. A number of socioeconomic and other demographic variables were associated with anemia. More anemia was found in urban than in rural areas.

Adolescent↗
PubMed1982

Nutritional anemias in the English-speaking Caribbean: a review of the literature.

A review of the published literature on nutritional anemias in the English-speaking Caribbean was carried out. Published articles on the subject are few in number and are concentrated in the larger islands such as Jamaica and Trinidad. Nutritional anemias are most prevalent among women of childbearing age. Iron and folate deficiencies and, to a much lesser extent, protein deficiency resulting from insufficient dietary intakes of these nutrients are the major nutritional factors contributing to this anemia.

Adolescent↗
PubMed1976

An evaluation of the use of changes in hair root morphology in the assessment of protein-calorie malnutrition.

A study was carried out to evaluate the use of changes in hair root morphology in the assessment of protein-calorie malnutrition (PCM) among a group of black West Indian children. The following five hair root characteristics were measured: percentage of anagen (the growing phase), percentage of telogen (the resting phase), percentage of atrophy, diameter of anagen bulbs, and shaft diameter. Significant differences in shaft diameter, percentage of anagen, and percentage of telogen were found only between well-nourished and severely malnourished children. Significant correlation coefficients were obtained between both bulb diameter and percentage of atrophy and muscle circumference. No significant differences in any of the hair root characteristics were obtained between children with nutritional marasmus and those with kwashiorkor. The method was found to be time-consuming; it can be used for differentiating well-nourished children only from those with severe PCM; and it is unsuitable for determining the prevalence of the three degrees of PCM. For these reasons, the method is not recommended for use in the field assessment of protein-calorie malnutrition.

Anthropometry↗
PubMed1975

The use of changes in hair root morphology in the assessment of protein-calorie malnutrition.

A study was carried out to evaluate the use of changes in hair root morphology in the assessment of protein-calorie malnutrition (PCM) among a group of Black West Indian children. Significant differences in mean shaft diameter, mean % anagen, and mean % telogen were found only between the well-nourished and the severely malnourished groups. No significant differences in mean % atrophy, and in mean diameter of anagen bulbs were found among well-nourished children, children with mild-moderate PCM, severely malnourished children, and children hospitalized for conditions with a secondary effect on nutritional status. The method was found to be time consuming; it can be used only for differentiating well-nourished from severely malnourished children; and it cannot be used for determining the prevalence of the different degrees of PCM. For these reasons, the method is not recommended for use in the field assessment of PCM.

Body Height↗
PubMedDate not supplied

Gold-nickel alloys in dental prostheses.

A gold-nickel master alloy was prepared by arc melting in an inert atmosphere and from it, mechanical test specimens and dental prostheses were made by centrifugal casting. The cast alloy had a yield strength of about 7,400 kg/cm2, with an elongation of 12%. The alloy was clinically tested in the form of partial dentures and crown and bridge materials. For the 32-month period these prostheses have been in use, no tissue reaction, tarnish, or corrosion had been observed.

Crowns↗