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Biomedical subjects

J Metz

Publications and source records attributed to J Metz.

At least 235 records · Page 13Linked to original sources
PubMed1976

[The pattern of distribution of free amino acids in human amniotic fluid related to the duration of pregnancy. Part I: Changes in concentration in normal pregnancy (author's transl)].

Gas-chromatographic measurement of 18 free amino-acids from about 500 specimens of amniotic fluid between the 10th and 41st week of pregnancy. Statistical methods showed different concentrations of amino-acids in amniotic fluid during pregnancy. Serine, cysteine, methionine and tryptophane show constant concentration. Valine tyrosine and hydroxyproline continuously decrease. The other amino acids tested here show a biphasic course of concentration, falling by about 40-70% between the 10th and the 30th week after which they remain stable. Alanin, threonine, glycine and ornithine show a clear increase of concentration. This diversity of concentration of amino-acids during pregnancy hints at the importance of various factors for the composition of amniotic fluid.

Alanine↗
PubMed1975

[Pathomorphogenesis of blistering in epidermolysis bullosa acquisita and epidermolysis bullosa dystrophica (author's transl)].

Electronmicroscopical examination on skin lesions of epidermolysis bullosa dystrophica recessiva (E.b.d.r.) and epidermolysis bullosa acquisita (E.b.a.) associated with Crohn's disease have demonstrated that blistering occurs between epidermis and dermis beneath the basal lamina. The structural defect concerns the anchoring fibrils only which are missing in the junctional zone of the involved skin. All other junctional structures are intact. Beneath the basal lamina a band-like zone of a moderate electrondense, amorphous material is seen in the skin-lesions of epidermolysis bullosa acquisita, less marked in epidermolysis bullosa dystrophica. Direct immunofluorescent investigation of involved skin of E.b.a. shows a pemphigoid-like fluorescent pattern at the basal lamina with antihuman IgG-, -IgM-, beta1c/beta1a and antihuman C1q-component. In epidermolysis bullosa dystrophica, however, a fluorescent pattern at the basal lamina was found only with anti-human IgG and Anti-C3. The pathogenetic importance of the immunoglobuline-deposits at the basal lamina is discussed in regard of the loss of anchoring fibrils and the subsequent vesication in these types of epidermolytic diseases.

Animals↗
PubMed1975

Tissue vitamin B-12 assay by a radioisotope dilution technique.

A method is described for the measurement of vitamin B-12 (B-12) in solid tissues by radioisotope dilution (RID) assay. The method is a modivication using double extraction of a serum B-12 RID assay which uses chicken serum as the B-12 binder. The method was developed and tested using human and bat liver specimens. Double extraction was shown to be more efficient than single extraction, and resulted in complete release of endogenous liver [57Co] B-12 administered to bats. Results using the RID assay in 16 humans and 17 bat liver specimens were compared with those obtained using the Lactobacillus leichmannii microbiological assay. Correlation was good, but the RID assay gave higher results using the microbiological assay appear to be due to inadequate extraction of B-12 from tissues.

Animals↗
PubMed1975

[Ultrastructure of the epidermis in seborrhoic dermatitis (author's transl)].

Electronmicroscopical investigation on 12 cutaneous biopsies of different localisation showed that the seborrhoic dermatitis is not comparable to a psoriatic tissue-reaction. Both, the cyto-morphological feature and the demonstrated localisation of the acid phosphatase are distinctly different from that of the psoriatic epidermis. The described changes are clearly more similar to the well known ultrastructural pictures of eczemateous reactions. In spite of the "eczema-like" ultrastructural picture seborrhoic dermatitis apparently can be separated from the allergic and irritant contact-dermatitis. Nevertheless, the epidermal alterations are also similar to chronic nummular eczema. They therefore are unspecific and do not allow any conclusion regarding the etiopathogenesis or nosological classification of this skin disease.

Acid Phosphatase↗
PubMed1975

Comparison of results of microbiologic and radioisotopic assays for serum vitamin B12 during pregnancy.

The serum vitamin B12 level falls progressively during pregnancy, when measured either by microbiologic assay or by a radioisotope dilution technique. The concentration of the vitamin assayed by radioisotope dilution was consistently higher than the value obtained by microbiologic assay. This discrepancy was greatest in early pregnancy and decreased as the duration of pregnancy increased. These results add further evidence to the hypothesis that changes in serum binders for vitamin B12 are of major significance in the pathogenesis of the observed fall in serum levels of the vitamin during pregnancy.

Biological Assay↗
PubMed1975

[Cutaneous paraneoplastic syndromes (author's transl)].

Cutaneous paraneoplastic syndromes are nonspecific skin manifestations provoked by malignant tumors of internal organs, and which, as a first or early symptom, may suggest the presence of a malignant primary disease. It is necessary to differentiate between the rare, obligatory paraneoplastic dermatoses which are independent of age and almost always tumor specific and skin manifestations which may appear facultatively, usually only in advanced age, as paraneoplastic syndromes. To be excluded from these are non-paraneoplastic skin tumor syndromes which are caused either by a similarly directed carcinogenia noxa or by a common genetic factor.

Acanthosis Nigricans↗
PubMed1975

Vitamin B12 metabolism in the fruit bat (Rousettus aegyptiacus). The induction of vitamin B12 deficiency and its effect on folate levels.

1. Vitamin B12 metabolism was studied in bats of the species Rousettus aegyptiacus, which live on an all-fruit diet in the wild. 2. There was a wide range in values for the serum vitamin B12 concentration of newly captured bats, but bats captured in the early spring had significantly higher mean serum vitamin B12 levels than bats captured in the early autumn. 3. There was an exponential decrease in serum vitamin B12 concentration with time in captivity for bats fed on a vitamin B12-deficient, all-fruit diet; the biological half-life was 80 d in serum, 109 d in liver and 164 d in kidney. 4. The main storage organ for vitamin B12 in the bats was the liver, mean content 1067 ng vitamin B12. After 50 d, injected [57Co]cyanocobalamin had equilibrated with body vitamin B12 stores, and 17% of the retained radioactivity was present in the liver. From these results it was calculated that the total body vitamin B12 content of the bat was c. 6500 ng. 5. The biological half-life of injected [57Co]cyanocobalamin was 70--88 d and the calculated daily requirement was 50--60 ng (0-2 mug/kg body-weight per d). 6. As serum vitamin B12 levels decreased, serum folate levels increased. The erythrocyte folate concentration increased significantly after 130 d on the all-fruit diet and then decreased to the initial values after 190 d. 7. Vitamin B12 metabolism in the fruit bat is similar in many respects to that of man, but on a 'weight-for-weight' basis the bat has a 5- to 15-fold greater requirement for this vitamin. 8. Vitamin B12 deficiency may be induced fairly rapidly in fruit bats fed on an all-fruit diet.

Animals↗
PubMed1975

Prevention of folate deficiency by food fortification. II. Absorption of folic acid from fortified staple foods.

The absorption of folic acid from maize, rice and bread fortified with pteroylglutamic acid was compared with that of an aqueous solution of pteroylglutamic acid in the same subjects. Feeding fortified maize and rice produced similar increments in folic acid concentration, which were approximately half those observed with the pteroylglutamic acid solution. Fortified bread produced a lower increment. Pteroylglutamic acid was found to resist destruction by boiling and baking at temperatures and times used for the conventional preparation of such foods. However, baking for longer periods resulted in a loss of folic acid activity. It is concluded that fortification of staple foods with folic acid may offer a practical adjunct to nutritional programs designed to improve the intake of essential nutrients.

Absorption↗
PubMed1975

Prevention of folate deficiency by food fortification. III. Effect in pregnant subjects of varying amounts of added folic acid.

Maise meal fortified with folic acid was administered to subjects in late pregnancy in a daily dose of either 500 or 300 mug of folic acid. Changes in hematological and folate nutritonal status were compared to those in subjects receiving 300 mug folic acid/day in tablet form, and also in subjects in a previous study who received unfortified maize meal (control group) or meal containing 1,000 mug folic acid/day. In all groups receiving folic acid, red cell and serum folate levels rose progressively, and the rate of rise increased with increasing doses of folic acid. Maize meal containing a daily dose of 500 mug folic acid produced an effect similar to that of 300 mug daily in tablet form. Maize containing 300 mug added folic acid daily was effective in preventing the progression of folate depletion in late pregnancy.

Dose-Response Relationship, Drug↗
PubMed1975

Prevention of folate deficiency by food fortification. IV. Identification of target groups in addition to pregnant women in an adult rural population.

In a rural Negro population subsisting on a predominantly maize meal diet, the incidence of folate deficiency was 43.8% in nonanaemic women in late pregnancy, 32.1% in nonpregnant women, and 18.6% in adult males. More than one-third of all subjects older than 60 were deficient. No instance of unequivocal vitamin B12 deficiency was revealed in 431 subjects sampled, and it is considered that the hazards of giving a small daily dose of folic acid in this population are negligible. These findings warrant food fortification with folic acid in this and similar population groups.

Adolescent↗
PubMed1975

Prevention of folate deficiency by food fortification. VII. The use of bread as a vehicle for folate supplementation.

Bread fortified to contain a daily dose of 900 mug folic acid was administered to patients in late pregnancy. The patients receiving the bread showed significant rise in red cell folate concentration. The rise was similar to that observed in women receiving a daily dose of 300 mug of folic acid in tablet form. It is concluded that bread may be used as a vehicle for folic acid fortification.

Africa, Southern↗
PubMed1975

The effect of vitamin E on haemolysis in paroxysmal nocturnal haemoglobinuria: in vitro and in vivo studies.

The administration of vitamin E, a natural antioxidant, to a patient with paroxysmal nocturnal haemoglobinuria (PNH) failed to diminish the urinary excretion of 59-Fe as monitored by 59-Fe whole body counting and urinary loss of isotope. However, in vitro vitamin E corrected the increased sensitivity of PNH red cells to haemolysis by hydrogen peroxide. These results support the concept that the susceptibility of PNH red cells to lipid peroxidation is an in vitro phenomenon bearing little relation to the mechanism of in vivo haemolysis.

Blood Transfusion↗
PubMed1975

Thrombocytopenia in trypanosomiasis.

In all of four patients with African trypanosomiasis, thrombocytopenia was present on admission to hospital or developed during the course of the illness. One patient with severe thrombocytopenia died following gastrointestinal haemorrhage shortly after admission to hospital. Kinetic studies in the other three patients showed marked pooling of platelets in the spleen in all, but severe shortening of platelet life-span in only one. Evidence of disseminated intravascular coagulation (DIC) was found in 3 patients, 2 of whom received heparin therapy. These findings provide evidence that thrombocytopenia is a feature of African trypanosomiasis and is due mainly to hypertrophy of the reticuloendothelial system which accompanies the infection. In some patients immune damage to platelets or platelet consumption as part of DIC may be an additional factor contributing to the thrombocytopenia.

Adult↗