Search PubMed⌕ Search

Biomedical subjects

A Vahlquist

Publications and source records attributed to A Vahlquist.

At least 127 records · Page 7Linked to original sources
PubMed1978

Plasma vitamin A transport and visual dark adaptation in diseases of the intestine and liver.

Quantitative analyses of plasma concentrations of retinol binding protein (RBP), prealbumin and total proteins were performed in normal subjects and in forty-two patients suffering from diseases of the intestine and liver. The visual dark adaptation ability (DAA) was also assessed. Reduction of DAA and of RBP and prealbumin levels was noted in patients with chronic liver disease and fat malabsorption. In sixty-eight patients with intestinal diseases the RBP concentration seemed to be reduced in relation to the degree and duration of steatorrhoea. Furthermore, inflammatory activity, as revealed by laborabory tests, markedly reduced the RBP level. Treatment with vitamin A increased the RBP and prealbumin concentrations and restored the DAA to normal in patients with malabsorption but normal liver function. In patients with liver disease reduced DAA and serum RBP values were not affected by vitamin A therapy. Only at RBP concentrations below half the normal was impairment of the dark adaptation observed, suggesting that serum RBP is a more sensitive indicator of vitamin A deficiency than measurement of dark adaptation.

Adolescent↗
PubMed1978

Acne treatment with oral zinc and vitamin A: effects on the serum levels of zinc and retinol binding protein (RBP).

The serum levels of zinc, vitamin A and retinol binding protein (RBP) were studied in 75 acne patients before and during oral treatment with zinc, vitamin A or placebo. In the zinc-treated patients an increase in the mean serum zinc level was seen after 2 weeks, when also the first clinical improvement occurred. After 4 weeks the zinc level had increased by about 30% and no further significant increase was observed during 3 months of treatment. In 33 healthy subjects there was an increase of 14% after 4 weeks of zinc therapy. Vitamin A and placebo induced no significant changes in the serum zinc status. Prior to therapy the serum levels of vitamin A and RBP were lower in the acne patients than in the controls. Zinc + vitamin A treatment raised the serum RBP value to normal after 4 weeks. In patients given vitamin A alone, a probable increase in RBP was achieved. Zinc and placebo treatment did not change the serum level of RBP.

Acne Vulgaris↗
PubMed1977

Effects of oral zinc and vitamin A in acne.

The effects of oral zinc sulfate (corresponding to 135 mg of zinc daily) alone and in combination with vitamin A (300,000 international units) daily on acne lesions have been compared with those of vitamin A alone and of a placebo. The number of comedones, papules, pustules, and infiltrates were counted at each visit. After four weeks, there was a significant decrease in the number of papules, pustules, and infiltrates in the zinc-treated groups. The effect of zinc plus vitamin A was not better than zinc alone. After 12 weeks of treatment, the mean acne score had decreased from 100% to 15%. The mechanism for the effect of zinc therapy in acne, to our knowledge, is not presently known.¿

Acne Vulgaris↗
PubMed1977

Serum zinc and retinol-binding protein in acne.

The serum levels of zinc and retinol-binding protein (RBP) have been determined in 173 patients with acne and compared with those of a control group. The RBP is a specific transport protein and its level in plasma reflects the amount of vitamin A available to the tissues. Patients with severe acne were found to have lower levels of RBP than either patients with mild acne or healthy subjects of the same age. In the case of males with severe acne, the mean serum zinc level was significantly lower than that of the control group. No such difference was observed for girls. The observed condition of low levels of zinc and vitamin A in the serum of patients with severe acne may provide a rationale for the clinically good effect of oral zinc treatment.

Acne Vulgaris↗
PubMed1976

Breast milk composition in Ethiopian and Swedish mothers. I. Vitamin A and beta-carotene.

The vitamin A and beta-carotene contents of breast milk were determined at different stages of lactation in three population groups: nonprivileged Ethiopian, privileged Ethiopian, and Swedish mothers. In addition, a fractionation of vitamin A giving the proportion of retinol was performed. The concentrations of retinol-binding protein (RBP) and (in part of the material) beta-carotene and prealbumin in plasma were also measured. The mean concentrations of vitamin A and beta-carotene in the milk from the Swedish mothers (period 0.5 to 6.5 months) were in the range of 40.0 to 53.1 and 16.3 to 20.8 mug/100 ml, respectively. For the privileged Ethiopian mothers (period 0.5 to 3.5 months) the corresponding ranges were 36.2 to 36.4 and 26.2 to 28.1 mug/100 ml and for the nonprivileged Ethiopian mothers (period 0.5 to 6.5 months) 28.1 to 33.1 and 23.9 to 25.6 mug/100 ml. Only the nonprivileged Ethiopian mothers were examined during a later stage of lactation (6.5 to 11.5 and 11.5 to 23.5 months). The concentrations of vitamin A and beta-carotene in their milk showed a downward trend. The proportion of retinyl ester (percentage of total vitamin A content) was significantly higher in the milk of Swedish mothers than in privileged and nonprivileged Ethiopian mothers. In the Swedish mothers retinol constituted 3.5% of the total vitamin A content of the milk; in Ethiopian mothers it was 15 to 30%. Determination of RBP in plasma showed normal values for Swedish mothers and lowered values for Ethiopian mothers--particularly the nonprivileged, in whom 14 of 81 values were below 20 mug/ml. RBP was demonstrated in colostrum, but only in a low concentration (in the order of 5 mug/ml).

Adult↗
PubMed1976

Zinc and vitamin A: serum concentrations of zinc and retinol-binding protein (RBP) in healthy adolescents.

The concentrations of serum zinc and retinol-binding protein (RBP) have been studied with special reference to pubertal development in 132 healthy adolescents and young adults (11-26 years of age). The RBP level remained low during the first three of the five stages of puberty (mean, about 30 mg/l). When puberty degree 4 had been reached, the mean RBP level increased to nearly adult values (about 40 mg/l), the boys having somewhat higher levels than the girls. Use of oral contraceptives significantly increased the RBP level. The mean zinc values were rather constant throughout puberty, but boys 13-14 years of age had significantly depressed values. There was a statistically significant correlation between the serum levels of zinc and RBP.

Adolescent↗
PubMed1975

The concentrations of retinol-binding protein, prealbumin, and transferrin in the sera of newly delivered mothers and children of various ages.

Umbilical-cord blood from 50 full-term newborns and capillary or venous blood from 226 children varying in age from 6 weeks to 16 years was examined for content of retinol-binding protein (RBP), prealbumin, and transferrin. The mean levels of the three proteins in the newborns were 21 mug/ml, 128 mug/ml, and 1.65 mg/ml, respectively. The corresponding maternal levels were 39 mug/ml, and 3.2 mg/ml. Paired serum values of mothers and newborns showed a correlation for both RBP and prealbumin but not for transferrin. The low levels of RBP at birth (about 50 per cent of that of nonpregnant women) increased rapidly over the first 6 months to a maximum of 31 mug/ml but declined thereafter to a mean level of about 26 mug/ml, which was maintained until the age of puberty when adult values were gradually attained. In serum, the prealbumin levels showed a similar development, whereas the transferrin values reached constant adult levels as early as 2 years of age.

Adolescent↗