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Biomedical subjects

R R Frants

Publications and source records attributed to R R Frants.

At least 235 records · Page 13Linked to original sources
PubMed1986

Effect of single and repeated doses of oral omeprazole on gastric acid and pepsin secretion and fasting serum gastrin and serum pepsinogen I levels.

The effect of omeprazole on gastric acid and pepsin secretion and fasting serum gastrin and serum pepsinogen I levels was studied in 12 healthy volunteers. Omeprazole, 40 mg enteric-coated granules, or placebo was given once daily for nine days in a double-blind crossover study design. Twenty-four hours after a single dose of omeprazole, mean basal and mean pentagastrin-stimulated acid output decreased significantly. This effect was more pronounced after nine days of treatment. Basal pepsin output was significantly reduced only in those subjects with basal anacidity during omeprazole treatment. Stimulated pepsin output was slightly reduced after a single dose but unaltered after nine days of omeprazole. Fasting serum gastrin and serum pepsinogen I levels increased significantly during omeprazole treatment. It is concluded that omeprazole is a potent and selective inhibitor of gastric acid secretion, probably without a direct effect on pepsin secretion. However, in cases of basal anacidity during omeprazole administration, basal pepsin secretion is reduced. During omeprazole treatment, fasting serum levels of gastrin and pepsinogen I rise.

Administration, Oral↗
PubMed1986

Pepsinogen A polymorphism in gastric mucosa and urine, with special reference to patients with gastric cancer.

Electrophoretic pepsinogen A patterns were determined in gastric fundic mucosa biopsies from 601 patients with various gastric disorders and 25 healthy volunteers. Pepsinogen A patterns with an intense fraction 5 appeared to be associated with gastric cancer and premalignant changes of the stomach (p less than 10(-9)). In 60 individuals pepsinogen A patterns were determined in normal mucosa from different parts of the stomach. No differences were found between these patterns. In 29 out of 59 gastric cancer patients pepsinogen A could be demonstrated in the macroscopically malignant tissue. In two cases a different pattern compared with uninvolved fundic mucosa was observed. During a follow up study, major changes in the pepsinogen A pattern were observed in 7 out of 56 patients. In 8.6% of the examined patients urinary pepsinogen A patterns differed considerably as compared with the pattern observed in the gastric fundus. The results suggest that the highly significant association between intense Pg5 (the product of the D gene) and gastric cancer or its precursors may be caused by genetic as well as non-genetic factors.

Gastric Fundus↗
PubMed1986

Alpha 1-antitrypsin in acute anterior uveitis and rheumatic diseases.

To test the pathogenetic role of the phenotype MZ of alpha 1-antitrypsin/alpha 1-protease inhibitor (PI) in acute anterior uveitis (AAU) and in different rheumatic diseases we examined 360 unrelated patients including 93 with AAU alone, 24 patients with AAU and ankylosing spondylitis (AS), 21 patients with AAU and Reiter's disease (RD), 26 patients with AAU, AS, and RD 54 patients with AS alone, 16 patients with RD alone, 115 patients with rheumatoid arthritis (RA) alone, and 11 patients with psoriatic arthritis (PA) alone. Of the 164 AAU patients, 80 had a single attack, and 84 had repeated episodes. There were neither significant differences between different groups of the patients and 120 healthy controls nor between patients with AAU alone and patients with AAU and AS or RD in the frequencies of the PI phenotypes tested. The results indicate that the PI MZ type is not closely associated with AAU, AS, RD, RA and PA and that it does not play any role in determining whether AAU shows a pattern of a single attack or repeated episodes, and whether AAU occurs alone or together with AS or RD.

Acute Disease↗
PubMed1985

The influence of omeprazole on the synthesis and secretion of pepsinogen in isolated rabbit gastric glands.

Regulation mechanisms of pepsinogen (EC 3.4.23.) synthesis and secretion were studied by following newly synthesized [14C]-labeled pepsinogen during culture of isolated rabbit gastric glands. Omeprazole, a substituted benzimidazole, while almost completely abolishing acid production at 10(-4) M, strongly stimulated secretion of preformed and newly synthesized pepsinogen. Although the pepsinogen synthesis at this concentration of omeprazole was reduced to about 55% of the control rate, a two-fold absolute increase of total secreted pepsinogen was found. This increase was not due to a non specific leakage through disruption of chief cell membranes, as no increase of lactate dehydrogenase in the culture medium could be demonstrated. The stimulated secretion was influenced neither by 10(-3) M cimetidine, 10(-3) sodium thiocyanate nor 10(-4) M atropine. No additivity was found between the carbachol (10(-4) M) or dibutyryl cyclic AMP (10(-3) M) and the omeprazole induced pepsinogen secretion.

Animals↗
PubMed1985

The alpha 1 antitrypsin variant PI WFINNEYTOWN in a family of Caucasian origin.

During a routine screening a slow moving variant PI WFINNEYTOWN was traced in a family of Caucasian origin. The variant is not identical to W SAL and W COL. W FIN was originally detected in an American family of different ethnic origin. It is suggested that heterogeneity exists at the gene level, which is not detectable with conventional methods at the protein level.

Female↗
PubMed1985

Assignment of human pepsinogen A locus to the q12-pter region of chromosome 11.

A 0.9kb cDNA fragment, corresponding to a large part of Rhesus monkey pepsinogen A mRNA, was used as probe for the chromosomal localization of the human pepsinogen A gene(s) using human-rodent somatic cell hybrids. Southern blot analysis of 14 human-Chinese hamster and three human-mouse cell hybrids, strongly indicates that the human PGA locus is on chromosome 11. The human-mouse hybrids, containing a translocation involving chromosome 11, allow sublocalization to the region q12-pter.

Animals↗
PubMed1985

Pepsinogen synthesis in monolayer culture of human and rabbit gastric mucosal cells.

We have established monolayer cultures of human and rabbit gastric mucosal cells and of isolated rabbit gastric chief cells. These cultures were capable of de novo pepsinogen synthesis and secretion, demonstrated by electrophoresis and subsequent autoradiography of cell lysates and growth medium after culture in the presence of 14C-labelled amino acids. Cultures could be maintained for 1 week without overgrowth by fibroblasts.

Animals↗
PubMed1985

Purification of the pepsinogen A isozymogens by means of high resolution ion-exchange chromatography. Evidence for post-translational modifications.

Total human pepsinogen (PG) was isolated from gastric fundic mucosa and PGA (formerly called PGI) from urine, using standard ion-exchange and gel filtration techniques. Gastric PGA was separated from PGC (formerly called PGII) either by immunoaffinity or high resolution ion-exchange chromatography (fast protein liquid chromatography, Pharmacia, Uppsala, Sweden). The individual PGA isozymogens 2, 3, 4 and 5 could be isolated to homogeneity with the aid of the same ion-exchanger. Evidence was obtained for the existence of secondary modifications of the PGA fractions 3, 4 and 5, electrophoretically overlapping the primary (genetic) isozymogens.

Chromatography, Gel↗
PubMed1985

Pepsinogen synthesis and secretion by isolated gastric glands.

De novo synthesis of pepsinogens was demonstrated in gastric glands isolated from rabbit and human gastric mucosa. The isolated glands were incubated in an amino acid free, Minimum Eagles Medium supplemented with a 14C labelled amino acid mixture. The glands were centrifuged at different time intervals and aliquots of gland homogenates and medium were run on polyacrylamide slab gels. Newly synthesized pepsinogens were demonstrated by autoradiography. Incorporation of 14C was detected after 30 minutes of culture and increased almost linearily with time over 4 h. By comparing the electrophoretic patterns after autoradiography, protein and pepsinogen activity staining, it was concluded that the glands synthesize mainly pepsinogens. Cimetidine, at a concentration of 10(-4)M strongly inhibited pepsinogen synthesis. Spontaneous secretion of pepsinogens into the medium was very low and relatively constant. Cyclic dibutyryl AMP markedly stimulated the secretion of pepsinogens into the medium. The results show, that isolated gastric glands are capable of synthesis and secretion of pepsinogens and that each function can be stimulated and inhibited selectively.

Animals↗
PubMed1985

Qualitative and quantitative determinations of pepsinogen I in gastric cancer and premalignant changes of the stomach.

Previous studies in rats have shown that stomach carcinogens cause a decrease of total pepsinogen content and a decrease of the fastest pepsinogen isozymogen in gastric mucosa before the appearance of carcinoma. In man the presence of Pg 5, and in particular a strong Pg 5, appears to be associated with gastric cancer. Low serum PG I levels were found in patients with gastric cancer, atrophic gastritis, intestinal metaplasia and gastric polyp. In this chapter we review the literature and report our results of PG I isozymogen and serum PG I determinations in 500 patients with various gastric disorders. It is concluded that premalignant changes of the stomach are associated with the presence of a strong Pg 5 isozymogen and with a low serum PG I level.

Gastritis, Atrophic↗
PubMed1984

Genetics of urinary pepsinogen: a new hypothesis.

A new genetic model is proposed to explain the inheritance of the urinary pepsinogen (PG1) polymorphism. Each main fraction, 3, 4 and 5, in the multibanded electrophoretic pattern, is determined by its own specific gene, B, C and D respectively. The intensity ratio of the fractions is principally determined by the number of gene copies. Accordingly, the PG1 phenotypes are determined by gene combinations, haplotypes, some of which may be identical to alleles in previous one locus models. Some critical families, not interpretable using previous genetic models, are presented to support the hypothesis. Preliminary population data from the Netherlands are described. The molecular background of this polymorphism and its relevance for gastric (pre)malignancy is discussed.

Adult↗
PubMed1984

Pepsinogen synthesis and secretion in isolated gastric glands.

De novo synthesis of pepsinogen was shown in isolated rabbit and human gastric glands after incubation of the glands in a 14C labelled amino acid enriched minimum Eagles medium. At regular intervals, glands and medium were separated and analysed by polyacrylamide gel electrophoresis. Newly synthesised pepsinogen was shown by autoradiography. Incorporation of 14C labelled amino acids was detected after only 30 min of culture and increased almost linearly in time for 4 h. By comparing the incorporation of label into total protein and into pepsinogen, it was concluded that pepsinogen formed 70-90% of the newly synthesised protein. Cimetidine, at a concentration of 160 micrograms/ml, strongly inhibited the synthesis of pepsinogen. Spontaneous secretion of pepsinogen into the medium was very low and relatively constant. Dibutyryl cyclic AMP considerably stimulated the secretion of pepsinogen into the medium. Histamine and pentagastrin did not influence the release of pepsinogen. These results show that isolated gastric glands are capable of synthesis and secretion of pepsinogen and that both can be selectively stimulated and inhibited.

Animals↗
PubMed1984

Salivary protein polymorphism in Kenya: evidence for a new AMY1 allele.

Salivary protein polymorphism was studied in 200 schoolboys, mainly Kisii and Luo from Kenya, East Africa. The frequencies of PR, PA, DB, PB and AMY1 genes were as follows: PR*1: 0.66, PA*(+): 0.18, DB*(+): 0.55, PB*2: 0.12, AMY1*A2: 0.008, AMY1*E: 0.03. These frequencies were compared with other population data, in particular from West African and US Negroes. The most interesting finding with respect to the gene frequencies is the low PB*2 frequency and the absence of AMY1*3 in Kenya. Furthermore, a new phenotype in the AMY1 system was described which suggests the presence of an allele with an estimated frequency of 0.02.

Adolescent↗
PubMed1984

Genetic study of Tunisian Berbers. II. Alpha 1-antitrypsin (Pi) polymorphism: report of a new allele (Pi S Berber).

The alpha 1-antitrypsin (alpha 1-AT) (Pi) polymorphism has been studied in three Berber groups of Tunisia by high-resolution isoelectric focusing. The results showed that actual Tunisian Berbers are mainly Caucasoid. A new variant of alpha 1-AT, tentatively called Pi S Berber, was found in the three Berber groups. On isoelectric focusing this variant was slightly more cathodal than the product of the usual Pi S allele. Family studies showed that the Gm-Pi linkage is probably close when the Pi locus supports the Pi P allele which is responsible for moderate (30%) serum alpha 1-AT deficiency.

Alleles↗