PubMed Health⌕ Search

Biomedical subjects

H Sommer

Publications and source records attributed to H Sommer.

At least 19 recordsLinked to original sources
PubMed1979

Development of a system useful for studying the formation of unstable alleles of IS2.

IS2-induced deletions of the gal control region were isolated in a plasmid carrying gal OP-308::IS2-7. This contains a 54 basepair long, unstable mini insertion within IS2, thus allowing constitutive expression of the gal structural genes. Deletion PPI is 11.9 kilobasepairs (kb) long and is Gal+ because it has retained the mini insertion. In PP4 7.2 kb DNA material including markers gal OP, chlD and pgl are deleted. PP4 has lost the mini insertion and is therefore Gal negative. DNA sequencing of the newly formed junction in PP4 reveals that the deletion terminates precisely at nucleotide 1 of IS2 and that no DNA sequence homology is involved in this IS2-mediated deletion formation. PPI segregates Gal- clones due to the loss of the mini insertion. One such segregant PPIS and PP4 both give only constitutive Gal+ revertants, which consist of the previously known mini insertions and also a new class of "supermini" inserts within IS2 of about 10 to 20 basepairs long. Therefore, PPIS and PP4 can be used to study various parameters involved in the formation of mini insertions.

Alleles↗
PubMed1979

Integration of IS3 into IS2 generates a short sequence duplication.

The Gal+ allele IS2-43 is known to segregate Gal- clones. Among 11 Gal- segregants, one was shown to be due to the integration of IS3 into IS2-43. Precise excision of the integrated IS3 element occurred at a rate of 5 x 10(-9)/cell/generation. DNA sequence analysis revealed that the termini of the IS3 element have the relation of imperfect inverted repeats and it is now flanked by a 3bp or 4bp duplication, a size which has not been seen before with other elements.

Alleles↗
PubMed1979

IS2-43 and IS2-44: new alleles of the insertion sequence IS2 which have promoter activity.

The sequence of two new IS2 alleles with promoter activity (IS2-43 and IS2-44) is reported. The alleles are identical and are formed by a 17 bp tandem duplication in an AT-rich region of IS2. This created a new RNA polymerase binding site. A mutation was found that increased the frequency of formation of these 17 bp duplications but not of another class of duplications, the "mini-insertions". This suggested that the mechanisms of formation of the two classes of duplications are different.

Alleles↗
PubMed1979

Dietary fiber and nutrient intake in Crohn's disease.

The mean daily intake of dietary fiber, sugar, starch, fat, protein, and total energy was determined in 35 patients with Crohn's disease and 70 normal controls by obtaining individual dietary histories. For each patient with Crohn's disease there two controls, matched for age, sex, and socioeconomic background. In the patients with Crohn's disease the mean dietary fiber intake was established as 26.6 +/- 1.4 g/day, compared to 22.3 +/- 0.9 g/day in the controls, and was thus significantly higher (P less than 0.05). When compared with the controls, the patients with Crohn's disease also exhibited a significantly higher consumption of sugar 156 +/- 14 versus 91 +/- 5 g/day (P less than 0.001), starch (211 +/- 10 versus 170 +/- 9 g/day (P less than 0.01)), and total energy (14.4 +/- 0.7 versus 12.3 +/- 0.5 MJ/ day (P less than 0.01)).

Adolescent↗
PubMed1979

Nucleotide sequence of the transposable DNA-element IS2.

The complete sequence of the transposable DNA element IS2 in gal OP-308:: IS2 (I) has been determined. This element is 1.327 bp long. The integrated element is flanked by a five base pair long sequence duplication. The termini of IS2 are not perfect inverted repeats, but a close approximation.

Base Sequence↗
PubMed1979

Therapy of Crohn's disease with metronidazole -- an uncontrolled trial --.

Twelve patients with Crohn's disease (C.D.), in whom there was no improvement of symptoms and signs under protracted corticosteroid and salicylazosulphapyridine medication, were treated with 1 000 mg metronidazole (M.) daily. Crohn's Disease Activity Index (CDAI) was used as a criterion of therapeutic response. Seven patients showed improvement of symptoms with a concomitant fall of the CDAI from 300 +/- 84 to 56 +/- 32 (mean +/- SD) after 10 to 45 days. In one patient, therapeutic success was judged to be doubtful, a negative result being obtained in 4 patients. During follow-up, which was maximally 21 months, patients failed to relapse while receiving a maintenance dose of 250 and 500 mg of M. per day. -- Judicious attempts at drug withdrawal were undertaken during the first 6 months but were invariably followed by a relapse. -- Metronidazole given over a protracted period did not give rise to side-effects. -- A reduction of anaerobic bacterial invaders of the intestine is suggested to underlie the favourable therapeutic effect of M.

Adolescent↗
PubMed1978

[The significance of the evocative test in the diagnosis of chronic pancreatitis (author's transl)].

To evaluate the predictive value of the evocative test (E.T.) in the diagnosis of pancreatitis, the E.T. was performed in 35 healthy subjects (group I), 65 patients with a presumptive clinical of chronic pancreatitis (group II), and 52 patients with proved chronic pancreatitis (group III). In group I, false positive results were obtained in 11,4% of the patients, the increase in lipase above the upper limit of normal was relatively small. The patients of group II gave abnormal E.T.'s in 63%, reduced faecal chymotrypsin activities being found in 40%, and steatorrhea in 28% of the cases. Positive E.T.'s were associated with abnormal chymotrypsin and faecal fat determinations in 51% and 27%, respectively. In group III,, a positive E.T. was obtained in 60%, the test results show a signifikant negative correlation with the extent of pancreatic exocrine insufficiency. In group of patients with confirmed chronic pancreatitis but without steatorhea, the E.T. was positive in 72%. The E.T. has a limited value in the diagnosis of early stages of chronic pancreatitis.

Chronic Disease↗
PubMed1978

Immune status in Crohn's disease. I. Leukocyte and lymphocyte subpopulations in peripheral blood.

Proportions and absolute numbers of circulating leukocyte populations and lymphocyte subpopulations (T- and B-cells) were determined in 33 patients with Crohn's disease (group CD), and were compared with those of age- and sex-matched healthy subjects. Group CD comprised 15 patients with newly diagnosed, short-standing, and untreated CD (group CD 1) and 18 patients with long-standing, previously drug treated CD (group CD 2). All CD groups showed a significant absoulte leukocytosis, based on a significant absolute and relative increase of the neutrophils, and, as far as group CD and CD 1 were concerned, also of the absolute number of monocytes. In group CD 1, absolute lymphocyte and relative as well as absolute T-cell numbers were close to normal. In contrast, in group CD 2 absolute as well as relative numbers of lymphocytes and absolute numbers of T-cells were highly significantly reduced, whereas the reduction of the relative T-cell concentration barely reached significance. The proportion of B-cells was significantly above normal in all patient groups, the absolute number in group CD only. Also group CD 1 showed considerably, though statistically insignificantly, higher than normal absolute B-cell numbers. In group CD 1 , there was an inverse correlation between absolute T-cell numbers and disease activity, and between absolute lymphocyte numbers and duration of disease. These data indicate that there is no gross numerical reduction of the carriers of the cell-mediated immunity as a primary predisposing factor for CD, but that a reduction of these cells occurs in the circulation after the disease has started.

Adult↗
PubMed1978

Gastric transmural potential difference in rats fed with a retionol-free diet.

The concentration of retinol is decreased in serum after periods of stress. The incidence of stress ulcers can be reduced in experimental animals and in man by high doses of retinol. It has been postulated that the stress-induced reduction of serum retinol may be implicated as one of the factors favouring the development of stress ulcers. Functional damage to the gastric mucosa triggered off by noxious agents and particularly ulcerogenic drugs is followed by a fall of the transmural potential difference (P. D.). This observation has led us to investigate whether retinol-depleted rats display an alteration of the P.D. as a parameter of gastric mucosal dysfunction, when compared with animals optimally supplied with retinol. In this study it should not be demonstrated that the P.D. differs between optimally fed and retinol-deficient animals in spite of severe retinol depletion.

Animals↗
PubMed1978

Pancreatic exocrine function in rats with severe retinol deficiency.

Starting from the fact that extensive retinol deficiency leads to morphological pancreatic alterations, the secretion of the gland and the specific enzyme activities in the pancreatic tissue were studied in rats fed a retinol-free diet for 70 days. No clear alteration of the exogen stimulated pancreatic secretion and of the enzyme content of the gland was observed.

Amylases↗