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H Blom

Publications and source records attributed to H Blom.

At least 55 records · Page 3Linked to original sources
PubMed1988

Gastric mucus gel layer thickness measured by direct light microscopy. An experimental study in the rat.

A method for measuring the thickness of the mucus gel layer present on the gastric mucosa is described. This method enables minimal handling of the mucosal specimens and thereby minimizes the errors connected with tissue handling. Male Sprague-Dawley rats were used. With the rats under general anesthesia, the stomach was excised and opened along the greater curvature, and full-thickness biopsy specimens from the corpus region were obtained by means of a skin biopsy punch. From these specimens a slice of mucosa, 1 mm thick, was rapidly cut out and put into a specially made glass chamber containing 0.9% NaCl. The chamber was sealed with a cover glass. Mucus gel layer thickness could then be measured in a conventional light microscope operated at a primary magnification of x120. This method was tested on two groups of 10 rats. The animals in the control group were given 1 ml of 0.9% NaCl, and the rats in the experimental group were given 1 ml of sodium salicylate, 75 mg/kg, dissolved in saline. After 15 min the animals were anesthetized and specimens prepared for measuring mucus gel layer thickness. In the control group, the mucus gel layer measured 145 microns, whereas in the experimental group it reached a thickness of 305 microns. The method proved to be easy to use, and the effects of pharmacologic substances on the mucus gel layer in the stomach could be investigated.

Animals↗
PubMed1987

The major acid-soluble proteins of Bacillus subtilis spores: partial amino acid sequence and forespore location of their mRNAs.

In Bacillus subtilis the alpha, beta, gamma and delta components comprise 80-90% of the total acid-soluble spore proteins (ASSPs). Sequence analysis demonstrates that alpha and beta share 32 of their first 36 amino acids and are closely related to the A and C ASSPs of Bacillus megaterium spores, confirming the results of analysis of their cloned genes. Despite the difference in apparent size of gamma and delta, they have identical N-terminal sequences (37 residues). Unless gamma and delta derive from very recently duplicated genes, it appears that gamma is derived from delta, either in vivo or during isolation. Although the sequenced regions of gamma and delta have no homology to alpha and beta, outside of the previously recognized pentapeptide recognition sequence for the spore endopeptidase, they share 10 and 15 residue peptides flanking this sequence with ASSP B of B. megaterium, but in reverse order. At least two groups of ASSPs have, therefore, been conserved between B. subtilis and B. megaterium: the multigene AC alpha beta family and the B gamma (delta) group. Sequence conservation in each group implies selection for functions in addition to storage. Both the alpha and beta components of B. subtilis ASSPs and their mRNAs are located in the forespore compartment of cells at t5.5 of sporulation, the time of most rapid ASSP synthesis. The sizes of these transcripts (250-350 bp) and their ability to direct the in vitro synthesis of ASSPs of mature size, indicate that genes for these ASSPs are monocistronic, consistent with dispersed map location. Synthesis of ASSPs is, therefore, coordinately controlled by selective transcription in the forespore.

Amino Acid Sequence↗
PubMed1986

Hypergastrinaemia produces trophic effects in stomach but not in pancreas and intestines.

Hypo- or anacidity, caused by antisecretagogues, stimulates gastrin release and leads to hypergastrinaemia. If drug treatment is maintained over a period of time, the hypergastrinaemia can be expected to give rise to trophic effects. We examined the trophic consequences of the very marked hypergastrinaemia produced by long-term treatment (16-20 weeks) of rats with large doses of the substituted benzimidazole, omeprazole, a potent and long-acting blocker of acid secretion. The weight of the stomach and the oxyntic mucosal thickness were increased, whereas the weight of the pancreas and the intestines and the thickness of the mucosa of the antrum and small and large intestine were unaffected. The number of exocrine cells (parietal, zymogen and mucous cells) were uniformly increased by 25-30%. The density of parietal and zymogen cells, expressed as number of cell nuclei per mm2 epithelium, was unchanged. The volume density of parietal cells, expressed as % of epithelial volume, was also unchanged, implying that the volume of the individual parietal cell had not increased. The density of endocrine ECL cells in the stomach increased 5-fold. Thus, the findings demonstrate a growth-promoting effect of the hypergastrinaemia on the oxyntic mucosa, the ECL cells in particular, and the lack of such an effect on the antrum, pancreas and intestines.

Animals↗
PubMed1986

A morphometrical analysis of the effect of a single therapeutic oral dose of doxycycline on cell membrane area of neutrophil polymorphonuclear leucocytes.

Previous authors reported that in-vitro incubation with doxycycline reduced the number and length of filopods projecting from the surface of neutrophils. In the present study, control neutrophils were harvested from 11 probands at time zero. The probands were then given an oral single-dose of 400 mg doxycycline monohydrate. Test cells were harvested 24 h later. Control cells and test cells were compared by means of quantitative morphometry applied to electron microscopy. No effect of doxycycline treatment could be demonstrated on cell area, cell volume and cell surface density. The results suggested that there is no effect of conventional doxycycline treatment on neutrophil filopods.

Adult↗
PubMed1986

Alterations in gastric mucosal morphology induced by long-term treatment with omeprazole in rats.

The effects of long-term treatment with omeprazole on the gastric mucosal morphology was studied. Eighty male Sprague-Dawley rats were used and divided into 4 equal groups. Half of the animals in 3 of the groups were given omeprazole, 40 mumol/kg body weight, orally once daily for 130 days. The remaining rats in these groups served as controls. Half of the rats in the fourth group were given subcutaneous injections with pentagastrin, this group received vehicle only. At the end of the treatment period, all animals were killed by vascular perfusion with fixative and the gastric corpus mucosae prepared for light and electron microscopy. Quantitative morphometry was used to evaluate eventual effects of treatment on the different epithelial cell types which are present in the corpus mucosa. Omeprazole treatment resulted in an increased mucosal thickness as a result of a proportional increase in all types of epithelial cells with the exception of the endocrine cells. These cells increased in number by 100%. A similar increase was seen after pentagastrin treatment. In the omeprazole-treated rats, there was also an increase in the size and number of pepsinogen granules within the zymogen cells. All changes in gastric mucosal morphology seen after 130 days of treatment with omeprazole turned out to be reversible and were not seen after a recovery period of 3 months.

Animals↗
PubMed1985

Trophic actions of E2 prostaglandins in the rat gastrointestinal mucosa. A quantitative morphologic study.

Adult, male Sprague-Dawley rats in groups of 10 received one of the following treatments orally twice daily for 3 wk: prostaglandin E2 (PGE2) 7.5 mg X kg-1, 15(R)-15-methyl prostaglandin E2 (MePGE2) at 0.2 or 2.0 mg X kg-1, or vehicle. After 18 h of fasting and 10-12 h after the last dose, the rats were anesthetized, and the gastrointestinal tract was fixed and processed for macroscopic and microscopic investigations. Trophic changes were more pronounced in the gastric antrum than in the gastric corpus or small intestine. The thickness of the antral mucosa was significantly increased by PGE2 and in a dose-related way by MePGE2. The mucosa of the gastric corpus became significantly thicker only with the higher dose of MePGE2. In all the prostaglandin-treated groups, the proportion of endocrine cells was reduced. Small--but sometimes significant--changes were registered in the proportions of the various exocrine cells. The parietal cells became significantly larger (+88%) in the rats treated with high doses of MePGE2. The secretory surface of the parietal cells was markedly increased by PGE2 and MePGE2. The enlargement of the secretory surface in animals treated with prostaglandins corresponded to a marked elevation of the basal gastric acid secretion and an increase in plasma gastrin levels. Hypergastrinemia can explain some, but not all, of the trophic changes observed in this study. Light microscopic examination of the duodenal and jejunal mucosa showed dose-related increases in villus heights and crypt lengths after treatment with MePGE2. Only the duodenal villus heights were increased by PGE2.

Animals↗
PubMed1985

Resistance of tracheal tubes 3.0 and 3.5 mm internal diameter. A comparison of four commonly used types.

The resistance of RAE, Rüsch, Mallinckrodt paediatric and Portex plain nasal and oral tracheal tubes with internal diameters 3.0 mm and 3.5 mm was calculated at air flows of 1 to 10 litres per minute. The flow resistance profiles of RAE and Rüsch tracheal tubes was generally higher than those of Mallinckrodt paediatric and Portex plain tubes. All RAE and Rüsch nasotracheal tubes of size 3.0 mm internal diameter and orotracheal tubes 3.0 mm internal diameter had a flow resistance exceeding 3.0 kPa litres/second at an air flow of 4 litres/minute. It is concluded that these tracheal tubes ought only to be used with assisted or controlled ventilation.

Equipment Design↗
PubMed1985

The structure of normal and regenerating rat oxyntic mucosa.

The morphology of the normal oxyntic mucosa is described. Different animal models for the production of gastric ulcers are briefly reviewed. In a series of rats, wounds were produced by cauterisation of the oxyntic mucosa. The mucosal regeneration process was then followed by morphometrical methods using light and electron microscopy. In particular, the regeneration of the acid-producing parietal cells was followed. Initially, the ulcer area is covered by primitive epithelial cells originating from the mucosa in the wound margin. These cells form the new gastric glands. With time, all specialised epithelial cell types which normally occur in the oxyntic mucosa can be recognised and, if regeneration is allowed to continue, the structure and function of these cells will normalise. However, the amount of glands and the number of parietal cells within the glands remain subnormal.

Animals↗
PubMed1985

A case of carbimazole-induced intrahepatic cholestasis. An immune-mediated reaction?

A patient is described with cholestatic hepatitis following the use of carbimazole. A liver biopsy specimen showed intracanalicular cholestasis and some mononuclear cell infiltrate in the portal triades, consistent with drug toxicity; indications of an autoimmune or viral pathogenesis were absent. Rechallenge with the drug precipitated jaundice and disturbed liver function once more. Carbimazole induced a blastogenic response of patient lymphocytes in vitro. Both may suggest the involvement of an immune-mediated reaction, especially as it has been shown that sensitized lymphocytes may produce a cholestatic factor on stimulation with antigen.

Aged↗
PubMed1984

Rectal diazepam compared to intramuscular pethidine/promethazine/chlorpromazine with regard to gastric contents in paediatric anaesthesia.

Sixty children, aged 1-12 years, were investigated with regard to gastric pH and volume before general anaesthesia. Thirty children (group D) received diazepam 0.75 mg/kg b.w. rectally 1 h before anaesthesia. Thirty children (group L) received a "lytic cocktail" (pethidine 28 mg, promethazine 7 mg, chlorpromazine 7 mg per ml) 0.05 ml/kg b.w. intramuscularly 1 h before anaesthesia. The pH values were significantly higher and the amount of gastric juice was significantly lower in group L compared to group D. The number of children in group L with gastric juice volume exceeding 0.4 ml/kg and the number of children with pH less than 2.5 was significantly smaller compared to group D. The number of children with both gastric pH less than 2.5 and gastric juice volume greater than 0.4 ml/kg was significantly smaller in the group receiving "lytic cocktail" intramuscularly compared to the group receiving diazepam rectally. Bile-stained gastric contents was not related to the gastric pH.

Child↗
PubMed1984

Trophic effect of pentagastrin on normal and regenerating parietal cells. A light and electron microscopic study in rats.

Gastric mucosal wounds were produced by cauterization of the oxyntic gland area in adult rats. From the first postoperative day, one group of animals was given two daily subcutaneous injections of pentagastrin, 250 micrograms/kg body wt, dissolved in hydrolyzed gelatin. The remaining rats served as controls and were given saline in the gelatin. After 90 days of treatment the animals were killed and the gastric mucosa was prepared for light and electron microscopy. Using stereologic techniques, data on parietal cells were obtained from both normal and regenerating mucosas. Pentagastrin induced a 2.3-fold increase in the parietal cell volume density in the regenerating mucosa and a 1.3-fold increase in normal mucosa. However, pentagastrin did not affect the ultrastructure of the parietal cells. Thus, the well-known trophic effect of pentagastrin on the gastric mucosa was confirmed; however, the absence of ultrastructural changes in the parietal cells suggests that the target for its trophic effect is likely to be the progenitor cell population.

Animals↗
PubMed1983

Cimetidine and parietal cell regeneration in experimental wounds in rat gastric mucosa. A light and electron microscopic study.

Cimetidine, 75 mg/kg body weight, was given twice daily by gastric tube to rats with experimental gastric ulcers. After 130 days' treatment the rats were killed, and sections from the wounds and normal mucosa were prepared for light and electron microscopy. Light microscopic studies showed that the regenerating mucosa in the wounds was thicker in the cimetidine-treated animals than in the controls. Stereological analyses demonstrated no differences in mean size of the parietal cells or in parietal cell volume density between the cimetidine-treated and the untreated groups, but an increase in the secretory surface density was detected in the parietal cells from rats that had been given cimetidine.

Animals↗
PubMed1983

Effects of pyloroplasty, truncal vagotomy, and antrectomy on parietal cell regeneration in experimental gastric wounds in the rat. A light and electron microscopic study.

Parietal cell regeneration in cauterized gastric wounds was studied in rats after antrectomy (Billroth I), pyloroplasty, and truncal vagotomy with pyloroplasty. Six to eight animals in each group were killed 90 or 130 days after operation, and in each rat stereological data were obtained from electron micrographs of 15 to 20 parietal cells from the wound area, from the normal mucosa beside the wounds, and from the mucosa in unoperated controls. Antrectomy reduced parietal cell size and mucosal thickness in normal mucosa and retarded parietal cell maturation and reduced mucosal thickness in the healing wounds. Pyloroplasty slightly reduced parietal cell size in normal mucosa and retarded maturation of the parietal cells in the wounds. If truncal vagotomy was added, the reduction in parietal cell size induced by the pyloroplasty was prevented in normal mucosa.

Animals↗