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Biomedical subjects

H Nielsen

Publications and source records attributed to H Nielsen.

At least 253 records · Page 14Linked to original sources
PubMed1989

Abdominal ultrasound versus intravenous urography in the evaluation of infravesically obstructed males.

In a prospective study intravenous urography (IVP) and abdominal ultrasonography (US) were compared in 100 consecutively admitted male patients with symptoms of infravesical obstruction. No pathology was found in 67 patients on IVP and in 61 patients on US. Both modalities disclosed 5 bilateral, 4 unilateral hydronephroses and one patient with contracted kidneys. IVP found 7 renal masses: one solid tumour, 2 "possibly solid" tumours and 4 "possibly cysts", whereas US found one solid tumour and 16 cysts. Both modalities detected 3 kidney stones, 5 bladder stones and 3 bladder tumours. It is concluded that "imaging" of the urinary tract is only indicated in cases of haematuria, elevated creatinine, history of renal calculous disease and other clinical suspicion of upper urinary tract disease. It is further concluded that US is preferable to IVP in this patient category due to (1) better characterization of renal masses, (2) the possibility of investigating the liver and the retroperitoneum in the same setting, (3) better evaluation of the prostate with respect to size, (4) better evaluation of the bladder, and (5) last but not least for economical reasons. However, bone metastases will be missed.

Humans↗
PubMed1989

"Achieving Health for All": a framework for nutrition in health promotion.

Achieving Health for All, a document released by Health and Welfare Canada, is a framework for nutrition in health promotion. Specific examples of the nutrition implications of the framework's challenges, mechanisms, and strategies are presented. Opportunities for involvement by individual dietitians/nutritionists as well as for The Canadian Dietetic Association are highlighted.

Canada↗
PubMed1989

Effect of Pseudomonas aeruginosa rhamnolipid on human neutrophil and monocyte function.

The effect of rhamnolipid purified from culture supernatant of Pseudomonas aeruginosa on human peripheral blood neutrophil and monocyte function was studied. It was shown that rhamnolipid at concentrations of up to 100 micrograms/ml did not affect neutrophil and monocyte chemotaxis towards various chemoattractants. The rhamnolipid by itself did not show chemotactic activity and did not induce any oxidative burst response. Preincubation of monocytes with rhamnolipid enhanced the oxidative burst response of these cells to phorbol myristate acetate (PMA) and to opsonized zymosan by 2 to 5 fold. The priming effect was observed both in a superoxide assay and in a chemiluminescence assay. However, rhamnolipid did not prime the neutrophil oxidative burst response. Monocytes/macrophages are involved in the inflammatory process in the lung infections caused by P. aeruginosa and oxygen radicals are known to cause tissue damage. Therefore the priming by rhamnolipid of monocytes for enhanced generation of oxygen radicals may play a role in the pathogenesis of tissue damage in the lungs of cystic fibrosis patients with P. aeruginosa infections.

Glycolipids↗
PubMed1989

Blood monocyte oxidative burst activity in acute P. falciparum malaria.

The release of superoxide anion from blood monocytes was studied in eight patients with acute primary attack P. falciparum malaria. Before treatment a significant enhancement of the oxidative burst prevailed, which contrasts with previous findings of a depressed monocyte chemotactic responsiveness. During treatment and after clinical recovery the activity of superoxide anion release normalized in all patients.

Animals↗
PubMed1988

Quantification of vesicular zinc in the rat brain.

By means of the Neo-Timm method it has recently been shown that zinc is present in a fraction of the round clear synaptic vesicles of certain boutons located primarily in telencephalic structures (Pérez-Clausell and Danscher 1985). It is believed that this zinc belongs to a fraction of the total brain zinc which is histochemically active (Frederickson and Danscher 1988) in that it can be visualized by means of e.g. the Neo-Timm and selenium methods (autometallography). The present study is based on the suggestion that the autometallographically developed zinc patterns represent a histochemical quantitative expression of this fraction of the total brain zinc. The different colours of the zinc pattern reflect local variations in the concentration of zinc containing vesicles. Large boutons with a high content of stained vesicles will show up darkly because of fusion of adjoining silver grains while smaller boutons with fewer zinc containing vesicles give rise to yellow staining of various shades. We have exploited this difference in staining of pattern by applying computerized optic densitometry to light microscopic sections treated according to the Neo-Timm and the selenium methods, respectively.

Animals↗
PubMed1988

N-acetylcysteine inhibits human neutrophil and monocyte chemotaxis and oxidative metabolism.

The effect of N-acetylcysteine (NAC) on human neutrophil and monocyte cell viability, chemotaxis, oxygen consumption and chemiluminescence was studied. It was found that NAC at concentrations higher than 3 X 10(-2) M resulted in neutrophil and monocyte cytotoxicity. The studies on the effect of NAC on neutrophil and monocyte chemotaxis showed that NAC inhibited chemotaxis of both cell types in a concentration dependent manner. NAC at 3 X 10(-2) M inhibited chemotaxis of both cell types by about 50% and at 10(-1) M inhibited PMN chemotaxis by 95% and MNL chemotaxis by 85%. The studies on the effect of NAC on neutrophil chemiluminescence demonstrated that NAC at concentrations of 1.5 X 10(-2) M, or higher, inhibited the response of the activated cells totally. When pH adjusted NAC or Mucomyst was used the inhibition was observed with higher concentrations of the drug (1.5 X 10(-1) M). NAC exhibited a similar pattern of inhibition on monocyte chemiluminescence response. These findings demonstrate that NAC, at concentrations obtainable in vivo by inhalation, impairs the chemotaxis and generation of oxygen radicals by human phagocytic cells. This property of NAC could have important implications concerning the prevention of tissue damage caused by these cells in inflammatory areas.

Acetylcysteine↗
PubMed1988

The secondary structure of large-subunit rRNA divergent domains, a marker for protist evolution.

The secondary structure of the large-subunit ribosomal RNA (24-26S rRNA) has been studied with emphasis on comparative analysis of the folding patterns of the divergent domains in the available protist sequences, that is Prorocentrum micans (dinoflagellate), Saccharomyces carlsbergensis (yeast), Tetrahymena thermophila (ciliate), Physarum polycephalum and Dictyostelium discoideum (slime moulds), Crithidia fasciculata and Giardia lamblia (parasitic flagellates). The folding for the D3, D7a and D10 divergent domains has been refined and a consensus model for the protist 24-26S rRNA structure is proposed. Two hundred seventy-seven nucleotide-long aligned sequences representing all or part of the D3, H32-33, D8, D9 and D10 divergent domains are used for the construction of unrooted phylogenetic trees either calculated from a nucleotide difference matrix, or determined with the PAUP programme based on the parsimony method. Both phylogenies suggest three major branchings, the first leading to the dinoflagellate (which branches off first), ciliate and yeast, the second to the slime moulds, and the last to the parasitic flagellates.

Animals↗
PubMed1988

Modulation of human neutrophil and monocyte chemotaxis and superoxide responses by recombinant TNF-alpha and GM-CSF.

The effects of recombinant TNF and GM-CSF on human peripheral blood neutrophil and monocyte chemotaxis and the superoxide response were studied. TNF exhibited a slight chemotactic activity for both cell types. Preincubation of neutrophils with as little as 40 units/ml strongly inhibited the neutrophil chemotaxis towards f-Met-Leu-Phe. The inhibition of monocyte chemotaxis required higher concentrations of TNF (greater than 400 units/ml). TNF at concentrations higher than 500 units/ml enhanced the generation of superoxide anions by neutrophils stimulated with f-Met-Leu-Phe. In contrast, TNF even at 2,000 units/ml did not prime monocytes for enhanced superoxide response. GM-CSF alone did not exhibit any chemotactic activity for any of the cell types tested. Preincubation of cells with GM-CSF inhibited chemotaxis of neutrophils but not of monocytes. GM-CSF was as potent as TNF in enhancing the generation of superoxide response by neutrophils. However, GM-CSF did not have any effect on monocyte superoxide response. The priming ability of TNF and GM-CSF on neutrophils was heat-sensitive. We conclude that TNF and GM-CSF play a more pronounced regulatory role on neutrophils than on monocytes. Inhibition of neutrophil chemotaxis followed by enhancement of the superoxide response by TNF and GM-CSF may provide an attractive mechanism by which these cytokines assist in fighting invading microorganisms.

Chemotaxis, Leukocyte↗
PubMed1988

Recombinant interleukin 1 alpha and beta prime human monocyte superoxide production but have no effect on chemotaxis and oxidative burst response of neutrophils.

We report that recombinant human IL 1 alpha and beta and the two synthetic short fragments 163-171 and 226-254 do not exhibit chemotactic activity for human peripheral blood neutrophils and monocytes. These products up to concentrations of 4 X 10(4) units/ml failed to show chemotactic activity. Furthermore, IL 1 alpha and beta failed to generate chemotactic factors from human serum. Recombinant IL 1 alpha, IL 1 beta, or IL 1 beta fragments 163-171 and 226-254 did not induce any superoxide response by monocytes or neutrophils. However, exposure of monocytes to recombinant IL 1 alpha or IL 1 beta resulted in enhanced generation of superoxide response following stimulation with PMA. No priming was observed in neutrophils. These results suggest that IL 1 alpha and beta are involved in regulation of monocyte oxidative burst response, but play no direct regulatory role on neutrophil function.

Chemotaxis, Leukocyte↗
PubMed1988

Do contrast media aggravate Fanconi's syndrome in rats? A comparison of diatrizoate, iohexol, and ioxilan.

Urine profiles (albumin, glucose, N-acetyl-beta-D-glucosaminidase [NAG], lactate dehydrogenase [LDH], L-gamma-glutamyltransferase [GGT], sodium, and phosphate) were followed for seven days after intravenous (IV) administration of either diatrizoate, iohexol, ioxilan, or saline in 24 Wistar rats with a tubular dysfunction induced by IV sodium maleate. Ioxilan and saline had a similar effect on albumin excretion, iohexol had an intermediate effect, and diatrizoate increased it significantly from day 2 to day 7. Glucosuria was significantly greater after diatrizoate than after the nonionic contrast media (CM) or saline. Diatrizoate delayed normalization of enzymuria, whereas iohexol and ioxilan did not. None of the CM affected urinary sodium or phosphate excretion. It is concluded that Fanconi's syndrome is significantly aggravated only by diatrizoate.

Animals↗
PubMed1988

Urine profiles following intravenous diatrizoate, iohexol, or ioxilan in rats.

The effects of intravenous diatrizoate, iohexol, ioxilan, or saline on albumin, glucose, sodium and the enzymes N-acetyl-beta-D-glucosaminidase (NAG), lactate dehydrogenase (LDH), and L-gamma-glutamyltransferase (GGT) in the urine of 24 normal Wistar rats were followed for seven days. During the first two hours after administration of diatrizoate, all profile components changed markedly; the albumin excretion was significantly greater than following ioxilan and iohexol; glucose, LDH, and GGT excretions were significantly greater than following ioxilan. Iohexol and ioxilan caused a higher excretion of albumin, LDH, and GGT than saline. Iohexol also increased glucose and sodium levels. Glucose and GGT were significantly higher following iohexol than following ioxilan. Both high osmolar and low osmolar contrast media may cause temporary glomerular and tubular damage. Urine profile components are affected most by diatrizoate, less by iohexol, and least by ioxilan.

Animals↗