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Biomedical subjects

R Arnold

Publications and source records attributed to R Arnold.

At least 541 records · Page 30Linked to original sources
PubMed1980

Somatostatin and gastrin release from canine stomach.

Somatostatin and gastrin release into the veins draining the stomach was studied in 27 anaesthetized dogs. Basal somatostatin-like immunoreactivity (SLI) in corpus veins (136 +/- 36 pg/ml) was significantly higher than in antrum veins (83 +/- 20 pg/ml; p less than 0.05) and the femoral artery (58 +/- 15 pg/ml; p less than 0.02). During peptone, pH 6.5, perfusion of the stomach, SLI concentration increased significantly in the corpus veins to approximately four times basal and in the antrum veins to three times basal, whereas SLI levels in the peripheral circulation remained constant. Peptone, pH 3.5, and sodium oleate did not stimulate gastric SLI. Gastric distension increased significantly SLI release from the corpus. In gel filtration studies 50%--70% of SLI from gastric vein plasma samples but greater than 90% from femoral artery samples eluted in the void volume of Sephadex G-25 columns. Gastrin secretion was stimulated significantly only by peptone, pH 6.5.

Animals↗
PubMed1979

Endocrinology of duodenal ulcer.

Several gastrointestinal peptides with proven or suggested endocrine or paracrine functions influence gastric acid secretion, gastrointestinal motility, and mucosal blood flow. Increased or decreased release of such factors could participate in the pathogenesis of duodenal ulcer disease by inducing increased gastric acid concentration in the duodenal bulb. To date, increased stimulation of parietal cells by gastrin has been demonstrated only in patients with gastrinoma, G-cell hyperplasia, gastric outlet obstruction, hyperparathyroidism, excluded antrum, and short bowel syndrome, but not in the usual duodenal ulcer disease. Also, a defective inhibition of parietal cell function by endocrine or paracrine factors, such as gastric inhibitory polypeptide, secretin, somatostatin and vasoactive intestinal polypeptide, seems not to exist in patients with duodenal ulcer disease. However, as long as the physiology of gastrointestinal peptides in gastric secretion and motility is not understood, a possible role of these factors in the pathogenesis of simple duodenal ulcer disease cannot be excluded.

Duodenal Neoplasms↗
PubMed1979

Beneficial effect of granulocyte transfusions in patients with defects in granulocyte function and severe infections.

A 3-year-old boy (patient A) with a congenital and a 24-year-old man (patient B) with an acquired granulocyte function defect received supportive granulocyte transfusions for the management of severe infections. The boy had suffered from recurrent infections since bith. His granulocytes showed in vitro almost no chemotactic responsiveness, an impaired phagocytosis and reduced intracellular killing of Candida albicans. Family studies suggested that it was an inherited autosomal recessive defect. The child developed a Pseudomonas pneumonia at the age of 3 years, which did not respond to antibiotic therapy. Granulocyte transfusions were then started and soon after the fever and pneumonia disappeared. Patient B showed the haematological signs of a preleukaemic state. He had 3 recurrent episodes of furunculosis which led each time to cellulitis and septic temperatures accompanied by symptoms of an enterocolitis. Tests of granulocyte function in vitro showed reduced intracellular killing of Staphylococcus aureus. Granulocyte transfusions were started, since no clinical improvement could be attained by antibiotics. With transfusion therapy, fever, cellulitis and enterocolitis disappeared each time.

Adult↗
PubMed1979

Lactoperoxidase binding to streptococci.

There have been conflicting reports regarding the binding of lactoperoxidase to bacterial cell surfaces. We describe here the effects of cell-bound lactoperoxidase on acid production by suspensions of Streptococcus mutans (NCTC 10449) in the presence of hydrogen peroxide and thiocyanate. Saline suspensions of log-phase bacteria were treated with 0.1 mg of lactoperoxidase per ml and were then washed thoroughly. The addition of hydrogen peroxide and thiocyanate markedly reduced the acid production of these lactoperoxidase-treated bacteria but had no effect on the acid production of untreated controls. After a 3-h incubation in saline, the lactoperoxidase-treated bacteria produced acid in the presence of hydrogen peroxide and thiocyanate at the same rate as untreated bacteria. These observations suggest that lactoperoxidase is initially bound to the cell surface in an enzymatically active form at a concentration sufficient to inhibit acid production. The lactoperoxidase is slowly degraded or desorbed as the bacteria stand in saline suspension.

Cell Membrane↗
PubMed1979

Appearance of gastrin and somatostatin in the human fetal stomach, duodenum and pancreas.

The gestational time of appearance of gastrin and somatostatin in the human fetal stomach, duodenum and pancreas was examined. Immunoreactive gastrin (IRG) is detected in antral, duodenal and pancreatic extracts of a 7.0-cm (crown-heel length) fetus. More IRG is extracted from the duodenum than the antrum. Duodenal IRG concentration from fetuses of 16.0--26.0 cm are higher than younger fetal and adult concentrations. Antral IRG concentrations are one tenth of the adult contents. Very small IRG concentrations are present in the human fetal pancreas. Gastrin immunohistochemical staining is positive first in duodenal (6.5-cm fetus) and later in antral (12.5-cm fetus) mucosa; pancreatic tissue is negative for gastrin immunohistochemistry. Type IV cells are encountered in antral and duodenal mucosa of 4.0-cm fetuses; other endocrine cells appear with fetal growth. Not until much later in gestation (21.0 cm) do typical G cells appear. These results suggest that early in fetal life gastrin is produced by the type IV cell. Somatostatin immunohistochemical staining is positive in stomach, duodenum and pancreas in 6.5-cm fetuses. Immature D cells are found in antral and duodenal mucosa of 5.0-cm fetuses and mature D cells in 11.0-cm fetuses.

Chromatography, Gel↗
PubMed1979

[Effectiveness of gnotobiotic measures in the treatment of acute leukemia: the results of a prospective randomized clinical study].

60 adult patients with acute leukemia (AL) previously untreated or in relapse received induction chemotherapy with different types of supportive care. Group A was decontaminated by nonabsorbable antibiotics in strict reverse isolation, group B was isolated only and group C was treated under routine hospital conditions. There were less infections in group A and B compared with group C. 76% of patients in group A achieved remission, in contrast to 57% in group B and 59% in group C. Late evaluation three years after termination of the study showed that all patients were dead except four patients being in first remission after discontinuation of maintenance treatment. Three patients were treated in group A, one patient in group C. However, the differences of survival and remission rates were not significant. Failure to demonstrate significant advantage of isolation and decontamination in treatment of AL was caused by insufficient suppression of microbes by the applied antimicrobial measures. Thus, it is suggested to investigate better antimicrobial treatment before gnotobiotic care is accepted as routine supportive treatment in AL.

Acute Disease↗
PubMed1979

Collection and cryopreservation of mononuclear blood leukocytes and of CFU-C in man.

For bone marrow reconstitution after hemopoietic failure as a consequence of the action of a variety of etiological factors, hemopoietic stem cells are needed. These have been derived in the past mainly from bone marrow. This report describes studies and their results that indicate that granulocytic progenitor cells, measured in cell culture systems as "colony forming units in culture - CFU-C", can be collected in large quantities from the peripheral blood of human blood donors by continuous flow leukapheresis. They can be stored at ultra-low temperatures. Their recovery rate after thawing and washing is better than 85%. In a canine model, evidence was obtained that the presence of CFU-C in a suspension of mononuclear blood leukocytes is also indicative for the presence of pluripotent hemopoietic stem-cells. Therefore it is suggested that stem cells can also be collected from human blood as an alternative source for bone marrow reconstitution.

Blood Preservation↗
PubMed1979

[Pathophysiology and clinical significance of gut hormones].

The different mode of secretion of the gut hormones (paracrine secretion--somatostatin. endocrine and neurocrine secretion--gastrin, CCK; neurocrine secretion--VIP, substance P), obscures the physiological significance of these hormones. However, the pathophysiological role of autonomous secreted hormones by endocrine tumours, is well established. Gut hormones are used for routine evaluation of gastrointestinal diseases. The therapeutic value of these substances has recently engendered considerable interest.

Blood Glucose↗
PubMed1979

[Release of pancreatic polypeptide (PP) or secretin after vagotomy (author's transl)].

The question has been risen whether "pancreatic polypeptide" (PP) determination is a suitable index for a successful vagotomy. Three months after truncal vagotomy (TV) there was only a slight postprandial increase of PP levels whereas five years after TV a normal PP response was found compared to controls. Vagal induced PP release was completely abolished after TV. Selective proximal vagotomy did not influence vagal and food stimulated PP release significantly. It can be concluded that PP determination does not prove to be a suitable index for a successful vagotomy.

Humans↗
PubMed1978

The antral gastrin-producing G-cell: biochemical and ultrastructural responses to feeding.

The effect of feeding on serum and antral immunoreactive gastrin (IRG) concentrations and on the ultrastructural appearance of antral G-cell granules has been examined. Serum and tissue IRG concentrations were dependent upon the length of time (12 or 48 h) the rats had been fasted before receiving food; IRG release was biphasic; the first peak was more pronounced in rats fasted 12 h. Antral tissue IRG content increased significantly postprandially. An initial depletion of antral IRG was seen in rats fasted 48 h. Examination of the subcellular distribution of antral IRG revealed more of the 5-15 min postprandal total IRG in the cytoplasm and less in the secretory granules. Ultrastructurally, G-cells from fasting rats contained mainly electron-dense granules. Five minutes postprandially numerous electron-lucent granules were observed. More electron dense granules were apparent 60 and 120 min postprandially. Fasting rats had the highest G-cell granule density index; a significantly lower index was observed 5 min postprandially. Indices at 60 and 120 min postprandially increased but were still lower than the fasting index. These studies indicate that gastrin biosynthesis is necessary for food stimulated gastrin release and that the electron density of the G-cells granules is not an accurate reflection of the G-cell gastrin content.

Animals↗
PubMed1978

High granulocyte yield with a simple method of filtration leukapheresis.

A simple continuous filtration leukapheresis has been devised whereby two Leuko-Pak filters can be charged and eluted within 5 h with approximately 121 of blood in a closed system of tubes. Blood flows by means of gravity without the use of pumps. Without premedication with prednisolone the average yield from 10 donors was 3.66 x 10(10) granulocytes per leukapheresis and after premedication with 150 mg prednisolone orally it was 6.44 x 10(10) granulocytes per leukapheresis. The in vitro function of filter granulocytes was not reduced even after premedication with prednisolone. In comparison with leukapheresis by blood cell separators this modified method of filtration leukapheresis offers the following advantages: 1) the granulocyte yield per litre of whole blood processes is higher, 2) technical assistants in a blood-bank can carry out the method on several donors simultaneously, 3) the method is more economical than leukapheresis by blood cell separators.

Cell Survival↗
PubMed1978

[Acute drug-induced agranulocytosis: comparison between openward treatment and antimicrobial decontamination in a plastic isolation bed system (retrospective study of 30 cases) (author's transl)].

Thirty patients with severe drug-induced agranulocytosis were admitted to the Ulm University Hospital between January, 1968 and October, 1976. All of 13 already infected patients treated with antimicrobial decontamination in a plastic isolation bed system survived. But nine of 17 patients treated in the open ward died. The cases were not randomised and there was a difference in age between the two groups, but nevertheless the results suggest that antimicrobial decontamination and isolation is superior to treatment in an open ward.

Adolescent↗