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Biomedical subjects

R R Frants

Publications and source records attributed to R R Frants.

At least 253 records · Page 14Linked to original sources

Effect of oral omeprazole on serum gastrin and serum pepsinogen I levels.

Fasting and meal-stimulated serum gastrin and serum pepsinogen I levels were determined in 8 healthy volunteers before, during, and after administration of 30 mg of omeprazole daily for 14 days. Fasting levels and the integrated increment of serum gastrin were significantly increased after 7 and 14 days of treatment with omeprazole, but not after a single dose. Fasting levels measured 2, 4, 7, 14, and 21 days after stopping treatment with omeprazole and the integrated increment of serum gastrin determined 7 and 14 days after discontinuation of omeprazole were not significantly different from pretreatment levels. Fasting serum pepsinogen I levels increased progressively during omeprazole treatment. This increase was significant after 7 and 14 days of treatment and 2 and 4 days after discontinuing omeprazole. These levels were not significantly different from pretreatment levels 7, 14, and 21 days after omeprazole treatment. Serum pepsinogen I did not significantly change after the test meal. It is concluded that fasting and meal-stimulated serum gastrin levels and fasting serum pepsinogen I levels increase significantly during treatment with 30 mg of omeprazole daily for 14 days, but after stopping treatment there is a rapid return to pretreatment levels.

Adult↗

Distribution of genetic variants of transcobalamin II in Nigerian black populations.

Transcobalamin II ( TC2 ) phenotyping was performed in Nigerian black males from several ethnic groups, using polyacrylamide gel electrophoresis in combination with autoradiography. The TC2 gene frequencies in the total Nigerian sample amounted to .064 (X), .124 (S), .498 (M), and .313 (F). Compared to white populations, the frequency of TC2 *X is low while the frequencies of TC2 *S and TC2 *F are high, which confirms previous studies on blacks. In some of the rare phenotypes we found, in addition to common TC2 variants, TC2 gene products with an electrophoretic mobility intermediary to X and S, and to M and F, indicative of further microheterogeneity in the genetic system of TC2 . The TC2 gene frequency data indicate interpopulation heterogeneity for this marker. Major differences were found between the Sudan and Guinea Savanna Group ( SGSG ) and the Middle Belt Group, and between the SGSG and the Ibos . The results of our comparative study confirm to some extent similar surveys, which have been based on the distribution of the ABO blood groups.

Autoradiography↗

Hereditary neuralgic amyotrophy. Clinical, genetic, electrophysiological and histopathological studies.

Clinical, genetic, electrophysiological and histopathological studies in a four-generation family with hereditary neuralgic amyotrophy (HNA) are described. Clinically two kinds of attack could be distinguished: (1) the classical type with pain and weakness lasting for weeks to months, leaving atrophy and sometimes residual weakness; 2) attacks consisting of recurrent pain and weakness lasting for a few days and occurring about once a week for several months, also resulting in persisting atrophy and weakness. Genetically a strong association was found between HNA and hypotelorism, probably due to pleiotropism of one single gene. Close linkage with any of 29 genetic markers was not present. The electrophysiological findings indicated that a local process in the brachial plexus, possibly demyelination or a conduction block, was the primary pathophysiological mechanism. Nevertheless, the sural nerve of the index case, biopsied 5 months after the onset of an attack, showed a decreased number of myelinated nerve fibres per cross-sectional area. Apparently, other parts of the peripheral nervous system may be affected subclinically in an attack of brachial plexopathy. The central and peripheral nervous system of his mother, 30 years after her last attack of HNA, showed only nonspecific changes. Tomacula were not seen in either case. HNA and hereditary liability to pressure palsies (HLPP) are distinctly different disorders.

Adolescent↗

Granular corneal dystrophy with late manifestation.

Ninety-two cases of granular corneal dystrophy, most of them belonging to 5 pedigrees are described. The age of manifestation in this Finnish type of granular dystrophy is first in the end of the second decade, and visual acuity is in mean normal through the whole life. An autopsy study showed no changes outside cornea elsewhere in the eyeball. In one family with granular dystrophy, another type of dystrophy, hereditary fleck dystrophy of the cornea, was accidentally found.

Adult↗

Genetic evidence for fetal origin of transcobalamin II in human cord blood.

Phenotypes of transcobalamin II (TC2) were determined in 95 maternal-cord serum pairs in order to identify the origin of TC2 in human cord blood. Unsaturated (apo) TC2 in serum was labeled with radioactive (57Co) cobalamin (CbI) and separated into isoproteins by polyacrylamide gel electrophoresis and autoradiography. Discordancy between the maternal and the cord serum type was observed in 45% of the pairs. The results demonstrated that, at the end of pregnancy, the fetus is capable of TC2 synthesis and that there is no detectable transplacental passage of maternal apo-TC2. Presence of maternal saturated (holo) TC2 in cord serum could be excluded in 9 informative discordant pairs by exchanging endogenously bound CbI with 57Co-CbI. Our finding that TC2 in human cord serum is of fetal rather than maternal origin suggests an essential role for fetal TC2 in CbI utilization and appears to contradict the hypothesis that transplacental passage of maternal TC2 may explain the normal fetal development in cases of congenital TC2 deficiency. The total immunoreactive TC2 content in 23 maternal serum samples collected at the end of pregnancy (812 +/- 175 pM CbI equivalent) was significantly higher than in the corresponding cord sera (605 +/- 148 pM; p less than 0.001) and did not significantly differ from the value in a control group of healthy male and female adults (841 +/- 192 pM). At the end of pregnancy, the apo-TC2 content in 12 maternal serum samples (760 +/- 347 pM) was significantly higher than in the corresponding cord sera (501 +/- 254 pM; p less than 0.05) and did not significantly differ from the value in the control group (747 +/- 137 pM).

Blood Proteins↗

Evidence of duplication of the human salivary amylase gene.

Isoelectric focusing of human parotid saliva reveals different alpha-amylase patterns reflecting qualitative and quantitative variations. A puzzling pattern, which shows three different amylase gene products, was found in four individuals. Based on this observation a model is presented in which the salivary amylase gene is duplicated. Family studies show that the AMY1*A2 gene forms a haplotype with the normal gene, AMY1*A1, whereas the AMY1*A3 gene still exists in a single form. The absence of homozygote 2-2 in offspring of 1-2 X 1-2 marriages and in population material, and the fact that the variant protein makes up about only 20-30% of the total amylase protein in heterozygotes can be considered as additional evidence supporting the hypothesis. The possibility that cis-acting regulatory variants are involved in the patterns with quantitative variation is discussed.

Amylases↗

Recent investigations of the first bleeder family in Aland (Finland) described by von Willebrand.

The still living members of the original bleeder family on the Aland Islands described by von Willebrand in 1926 have been reinvestigated by using modern laboratory techniques for the measurement of the Factor VIII complex and with regard to platelet aggregation. The low level of F VIII : C activity demonstrated in 1957 could be confirmed in some of the family members, who however all had only mild bleeding symptoms. More consistently, in 6 out of 10, a low F VIIIR : Ag was found; all of those also had a low F VIII : RCoF. In none of the members were excessively low values for any of the parameters found. However, the spectrum of the whole F VIII complex indicates that the original family described by von Willebrand belongs to von Willebrand's disease, type I.

Adolescent↗

Alpha 1-antitrypsin and acute anterior uveitis.

To test the pathogenetic role of the phenotype MZ of alpha 1-antitrypsin/alpha 1-protease inhibitor (PI) in acute anterior uveitis (AAU), 156 patients with AAU were examined. Sera of all patients and 120 healthy controls were PI-typed using isoelectric focusing. There were no significant differences in PI MZ frequencies either between the patients with AAU (4.5%) and the controls (4.2%), or between AAU patients with associated rheumatic diseases (4.8%) and AAU patients with no associated disease (4.3%). The results indicate that the PI MZ type is not closely associated with AAU among Finns.

Acute Disease↗

Parental alpha 1-antitrypsin (PI) types and meiotic nondisjunction in the aetiology of Down syndrome.

In 100 children with Down syndrome (DS), the parental origin of the supernumery chromosome 21 was investigated. In 76 out of the 100 cases the polymorphic regions were informative, i.e. the nondisjunction could be traced. Assessment of the alpha 1-antitrypsin/alpha 1-protease inhibitor (PI) types in these DS children revealed a significantly higher value of non-M PI variants (P less than 0.05). In their fathers the non-M PI variants were not increased, not even in those in whom nondisjunction had taken place. A clearly significantly higher value (P less than 0.001) of non-M PI variants was found in their mothers, particularly when only the MS and MZ types which are recognised as deficiency variants were considered. Most striking, however, is the almost 5-fold increased frequency of MS and MZ types found in mothers where the nondisjunction had occurred during the first meiotic division. This would suggest that PI deficiency interferes with some process leading to non-disjunction. If these findings are confirmed, application of Bayes' theorem enables us to estimate the risk for MZ and MS heterozygous women to have a DS child: this would be 3- to 4- fold higher than for MM homozygous women. This would be of interest for genetic counselling and enhance the benefits of prenatal diagnosis programmes.

Adult↗

The Gm--Pi linkage heterogeneity in view of Pi M subtypes.

In this study linkage between the loci for Gm (gamma-type heavy-chain immunoglobulin markers) and Pi (alpha 1-antitrypsin/alpha 1-protease inhibitor) has been shown in families segregating for the Pi M subtypes (M1, M2, M3 and Msal) as identified by separator isoelectric focusing . The estimate for the Gm--Pi (M type) recombination is 0.29 (95% limits 0.24--0.37) at a peak lod score of 4.31 and with no sex difference. This value is not significantly different from updated recombination frequency estimates for Gm--Pi in Pi MS (0.26) and Pi MZ, SZ and FZ families (0.21). The overall Gm--Pi recombination fraction estimate of 0.26 (95% limits 0.23--0.30) at a peak lod score of 20.75 must now be considered as solid. There is a significant heterogeneity within the male Pi MZ families in that the new Finnish families show a higher recombination between Gm and Pi. There is also a possible segregation distortion (Z:M = 23:8). The heterogeneity is discussed in terms of haplotypes, the behaviour of which could be determined by linked genes or chromosomal rearrangements. The possibility that the alpha 1-antitrypsin level influences recombination frequency has not been ruled out, but cannot explain the heterogeneity within Pi MZ families.

Alleles↗

Comparison of the PI patterns of alpha 1-antitrypsin on acid starch gel electrophoresis and isoelectric focusing.

An acid starch gel electrophoresis procedure was developed for recognition of PI M subtypes of alpha 1-antitrypsin, proving that their electrophoretic mobilities correspond to their relative isoelectric points on isoelectric focusing. From transfer experiments, it could be concluded that the PI patterns obtained after acid starch gel electrophoresis and isoelectric focusing are formed by identical molecular populations. These findings justify the replacement of acid starch gel electrophoresis by isoelectric focusing as the method of choice for typing, including the assignment of new PI variants.

Electrophoresis, Starch Gel↗

A new unstable PI M variant of alpha 1-antitrypsin in a Finnish isolate.

During family and population studies in a Finnish isolate (Salla), a variant of alpha 1-antitrypsin, tentatively called PI MSAL was found. On isoelectric focusing this variant was slightly cathodal to M3. With the aid of acid starch gel electrophoresis, differentiation from M3 proved reliable, because the variant was unstable in that system. The variant also showed an increased lability at + 56 degrees C and physiological pH and a decreased stability at pH 4.5 and room temperature compared to the other M subtypes. By genealogical studies it was possible to trace a common ancestor, a settler arriving to the parish around 1680, for the three families where the variant was found.

Electrophoresis, Starch Gel↗

Erythrocyte superoxide dismutase deficiency in Fanconi's anaemia established by two independent methods of assay.

Erythrocyte superoxide dismutase (SOD; E.C.1.15.1.1) levels were quantitated in human haemolysates, both by an immunological technique and by an activity assay. The erythrocyte SOD activity level in a group of seven Fanconi's anaemia patients was significantly decreased (27%, on the average) compared to a control group of nineteen healthy individuals. The fact that both the activity per antigenic unit and the electrophoretic mobility of the erythrocyte SOD was normal indicates that the deficiency in these Fanconi's anaemia patients is most probably not due to a mutation in the structural gene for the enzyme but more likely due to a disturbed mechanism regulating the SOD level in the erythrocyte.

Anemia, Aplastic↗

New genetic variants of parotid salivary amylase.

Isoelectric focusing can reveal at least two heterozygotes of the Amy1R class of variants. Family data on these variants show co-dominant inheritance for both alleles with respect to the normal Amy1A allele. The frequency of the alleles Amy1R1 and Amy1R2 in the Dutch population (n = 144) amounts to 0.006 and 0.03, respectively. Electrophoretic analysis of whole parotid saliva from different Amy1R phenotypes and of purified normal and Amy1R1 gene products indicates that the variant proteins differ from the normal protein by enhanced deamidation of asparagine and/or glutamine residues.

Alleles↗

Reliable classification of six Pi M subtypes by separator isoelectric focusing.

For the first time, segregation of three common PiM alleles in family material is verified by application of separator isoelectric focusing. A new nomenclature system for the Pi M subtypes is used, whereby the common subtypes are designated according to their physicochemical properties; the most anodal type is called Pi M1, the intermediary one Pi M2, and the most cathodal variant Pi M3 (previously called Pi M2). Pi gene frequencies from Finnish, Dutch and Black populations are presented. The PiM2 allele was rather high in Finns (0.12) but low (0.04) in the West African Bozo. The PiM3 was found with a frequency of 0.13 in Dutch, 0.08 in Finns and 0.02 in Bozo. A previous Finnish sample was retested with the new subtyping method and the six-subtype distribution was found to be in good Hardy-Weinberg equilibrium. The validity of the Pi polymorphism for population genetics, linkage analysis and parentage testing is discussed.

Africa, Western↗