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Biomedical subjects

M Kristensen

Publications and source records attributed to M Kristensen.

At least 37 records · Page 2Linked to original sources
PubMed1994

[Abnormal flora in the small intestine. Diagnostic evaluation of the H2 breath test].

Jejunal aspiration in order to diagnose intestinal bacterial overgrowth is more unpleasant for patients than breath testing. The object of this study was to compare the results of the glucose H2 breath test and the lactulose H2 breath test with the results of intestinal culture. On separate days, cultures of intestinal fluid collected from the Treitz region, glucose H2 breath tests (80 g glucose) and lactulose H2 breath tests (15 g lactulose) were undertaken in 20 patients with diseases predisposing to small intestinal bacterial overgrowth and in 20 controls. Twelve patients had bacterial overgrowth. Abnormal glucose H2 breath tests were observed in 11 patients, ten of whom had bacterial overgrowth. Glucose H2 breath tests were normal in seven out of eight patients without bacterial overgrowth. Only four patients had an abnormal lactulose H2 breath test. It is concluded that the glucose H2 breath test is acceptable for diagnosing bacterial overgrowth, whereas the lactulose H2 breath test in not.

Adult↗
PubMed1994

Interleukin-8 secretion and 15-lipoxygenase activity in rheumatoid arthritis: in vitro anti-inflammatory effects by interleukin-4 and interleukin-10, but not by interleukin-1 receptor antagonist protein.

We have examined the ability of interleukin-4 (IL-4), interleukin-10 (IL-10) and interleukin-1 receptor antagonist protein (IL-1ra) to regulate spontaneous interleukin-8 (IL-8) production in cultured SF mononuclear cells (SFMC) from RA. Furthermore, we examined whether IL-4, IL-10, or IL-1ra could influence the production of the arachidonic acid products leukotriene B4 (LTB4), 12-hydroxy-eicosatetraenoic acid (12-HETE) and 15-hydroxy-eicosatetraenoic acid (15-HETE). IL-4 induced a maximal suppression of 75% in the IL-8 secretion in SFMC from 10.0 ng/ml down to 2.5 ng/ml after 24 h and from 17.2 ng/ml to 4.2 ng/ml after 72 h of culture. IL-10 induced a 55% inhibition of the IL-8 secretion at 24 h and a 40% inhibition at 72 h. IL-1ra did not change the spontaneous IL-8 secretion from rheumatoid SFMC. We also examined, whether addition of IL-4, IL-10 or IL-1ra was able to modulate formation of the arachidonic acid products LTB4, 12-HETE and 15-HETE in cultured SF cells, stimulated with the calcium ionophore A23187. 15-HETE was not detected in untreated cultures, nor in IL-10 or IL-1ra treated cultures. IL-4, however, stimulated the formation of the anti-inflammatory mediator; 15-HETE (23 ng/10(6) cells). These results suggest that IL-4 or IL-10, could have beneficial anti-inflammatory effects in RA.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1994

Heterogeneity of neocortical cerebral blood flow deficits in dementia of the Alzheimer type: a [99mTc]-d,l-HMPAO SPECT study.

Regional cerebral blood flow (rCBF) was measured with high resolution brain dedicated single photon emission computer tomography (SPECT) and [99mTc]-d,l-hexamethyl-propylene-amine-oxime (HMPAO) in 25 patients with probable Alzheimer's disease and in 25 control subjects, selected according to rigorous inclusion and exclusion criteria. The aim was to analyse the topography of rCBF deficits in individual patients. In the group of patients with Alzheimer's disease as a whole, global CBF was reduced, but a factorial analysis of variance did not show disproportionate reduction of rCBF in any brain region. A parametric analysis of the rCBF data in individual patients was carried out with reference to normal values for internal rCBF ratios and to 13 different abnormal rCBF patterns. These theoretical patterns were predefined by showing significant hypoperfusion in at least one, or in any relevant combination of two, three, or four, of four major brain regions (a left and right frontal and a left and right posterior region). All patients with Alzheimer's disease and none of the control subjects had an abnormal rCBF pattern. Eleven of the 13 different patterns were seen in the patients. Frontal changes were seen in 19 (76%) of the patients, more often than previously reported. No single Alzheimer's disease pattern could be derived from our data. The number of regions with hypoperfusion, but not the presence of frontal changes, correlated significantly with the duration of disease. It is concluded that a clinical diagnosis of probable Alzheimer's disease is associated with heterogeneous patterns of rCBF deficits as measured with SPECT and [99mTc]-d,l-HMPAO. This heterogeneity may reflect different stages of the disease or cognitive subtypes and help explain published discrepancies concerning the topography of hypoperfusion in Alzheimer's disease. An analysis of individual rCBF data may add important information in the investigation of diseases with heterogeneous effects on the brain.

Adult↗
PubMed1994

Localisation of interleukin 8 in the synovial membrane, cartilage-pannus junction and chondrocytes in rheumatoid arthritis.

Interleukin-8 (IL-8) may play an important role in the development of synovitis in rheumatoid arthritis (RA), in that it is a powerful chemoattractant for neutrophils and T cells. The aim of this study was to examine the distribution of IL-8 in the synovial membrane and cartilage, from RA, osteoarthritis (OA) and normal joints. By immunohistochemical techniques, IL-8 was shown to be present in the lining layer cells in RA (87%) and in OA (62%). By contrast, only a few of the normal synovial lining layer cells (14%) contained IL-8. Deeper in the membrane the number of IL-8 positive cells decreased. Only vessels were highly positive for IL-8. At the RA cartilage-pannus junction 26% of the cells contained IL-8, whereas at the OA cartilage-pannus junction 8% of the cells were IL-8 positive (P < 0.05). Chondrocytes present in joint surface cartilage stained positive for IL-8 in an average of 20% of the cells of both RA and OA. These results provide histological evidence that IL-8 is present in the arthritic synovial tissue and cartilage, and is distributed in a manner that may form a chemotactic gradient, which favours localisation of neutrophils to the joint lumen.

Adult↗
PubMed1993

[Freezing of human embryos: the first Danish results].

The first human pregnancies reported in Denmark following in vitro fertilization and embryo transfer of frozen and thawn embryos are presented. A total of nine embryo transfers, with a mean of one point eight embryos per transfer, were carried out, resulting in three singleton pregnancies. The benefits for the infertile couple, the ethics and technical aspects are discussed with respect to Danish legislation.

Cryopreservation↗
PubMed1993

Localization of tumour necrosis factor-alpha (TNF-alpha) and its receptors in normal and psoriatic skin: epidermal cells express the 55-kD but not the 75-kD TNF receptor.

The distribution of TNF-alpha, p55 TNF receptor (TNF-R) and p75 TNF-R in normal skin and uninvolved and lesional skin from psoriasis patients has been investigated, using specific mono- and polyclonal antibodies. In normal skin, and uninvolved and lesional skin from psoriasis patients, p55 TNF-R is associated with epidermal keratinocytes and a network of upper dermal dendritic cells. This suggests that the actions of TNF-alpha on epidermal cells in vivo are mediated by binding to the p55 TNF-R. In lesional psoriasis skin, there was staining of the parakeratotic stratum corneum and increased expression of p55 TNF-R in association with upper dermal blood vessels. Staining for p75 TNF-R in normal skin was restricted to eccrine sweat ducts and dermal dendritic cells, and was absent from the epidermis. In lesional psoriasis skin, there was staining for p75 TNF-R in association with upper dermal blood vessels and perivascular infiltrating cells. TNF-alpha in normal skin was predominantly localized to the basal cell layers of the epidermis, and was seen in association with eccrine ducts and sebaceous glands. In lesional psoriasis skin, and to a lesser extent in uninvolved psoriasis skin, TNF-alpha was distributed throughout the epidermis, and was also specifically localized to upper dermal blood vessels. Up-regulation of TNF-alpha, p55 TNF-R and p75 TNF-R on dermal blood vessels in psoriasis may play an important role in the pathogenesis of this condition by promoting cutaneous recruitment of inflammatory cells.

Humans↗
PubMed1993

ETH615, a synthetic inhibitor of leukotriene biosynthesis and function, also inhibits the production of and biological responses towards interleukin-8.

ETH615 (4-(2-quinolylmethoxy)-N-(3-fluorobenzyl-phenyl-amino-methyl -4- benzoic-acid), a synthetic inhibitor of leukotriene B4 production and activities, was tested for its effect on the production of and biological responses towards human interleukin-8. We found that ETH615 inhibits lipopolysaccharide-induced (LPS-induced) expression of interleukin-8 messenger-RNA (mRNA) and interleukin-8 production in human peripheral blood mononuclear cells. We also observed that ETH615 completely inhibited interleukin-8 as well as leukotriene B4 directed chemotaxis of human neutrophils in a dose-dependent manner. A moderate effect on fMLP-directed neutrophil chemotaxis was observed. Further, no significant effect on either interleukin-8, leukotriene B4 or fMLP-directed T-cell migration was observed. These results further support the concept of a cytokine-leukotriene regulatory circuit and encourage the establishment of clinical trials testing the effect of ETH615 on inflammatory skin diseases, which are characterized by high levels of interleukin-8 and leukotriene B4 in lesional skin.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1992

The effect of second-line antirheumatic drugs on interleukin-8 mRNA synthesis and protein secretion in human endothelial cells.

Interactions between interleukin 8 (IL-8) and endothelial cells play an important role in the emigration of mononuclear cells from the blood into areas of inflammation. We examined the ability of specific second-line antirheumatic drugs to regulate (IL-8) gene expression and protein secretion in interleukin 1 (IL-1) stimulated human umbilical vein endothelial cells and peripheral blood mononuclear cells. The drugs sodium aurothiomalate, D-penicillamine and sulphasalazine were all able to modulate IL-8 mRNA synthesis in and protein secretion from endothelial cells. A bimodal effect was observed: at low concentrations IL-8 was suppressed, whereas higher concentrations resulted in an increased IL-8 production. In endothelial cells, treatment with hydrocortisone led to a linear suppression of IL-8 production in concentrations ranging from 0.5 micrograms/ml up to 500 micrograms/ml. Sulphapyridine, auranofin, hydroxychloroquine and methotrexate, had no effect on IL-8 secretion in endothelial cells. By contrast, 5-aminosalicylic acid induced a threefold increase in the IL-8 release. In peripheral blood mononuclear cells it was only possible to suppress the IL-8 production by hydrocortisone treatment. These results indicate that suppression of IL-8 production in endothelial cells could be an important factor in the mode of action for a number of second-line antirheumatic drugs.

Anti-Inflammatory Agents↗
PubMed1992

Distribution of interleukin 1 receptor antagonist protein (IRAP), interleukin 1 receptor, and interleukin 1 alpha in normal and psoriatic skin. Decreased expression of IRAP in psoriatic lesional epidermis.

The distribution of interleukin 1 alpha (IL-1 alpha), type 1 interleukin 1 receptor (IL-1R), and the interleukin 1 receptor antagonist protein (IRAP), was investigated in biopsies of normal skin, and in uninvolved and lesional skin of patients with psoriasis, using specific monoclonal antibodies. We report the novel finding that IRAP is distributed throughout the living layers of the epidermis in normal skin, and is also associated with sebaceous glands and eccrine sweat glands. Our finding that the inhibitor protein IRAP is present in areas where the pro-inflammatory cytokine IL-1 alpha is distributed provides strong evidence in favour of a cytokine regulatory system in normal skin. We further document for the first time that IL-1R in normal skin is localized to the living layers of the epidermis, sebaceous and eccrine glands, as well as to a prominent network of dermal dendritic cells, and upper dermal blood vessels. There was a consistent reduction in the level of IRAP expression in lesional compared with uninvolved skin in biopsies from six out of seven psoriasis patients. Decreased IRAP expression in lesions of psoriasis indicates that alterations in the level of this inhibitor protein may be important in the pathogenesis of inflammatory skin conditions.

Epidermis↗
PubMed1992

A controlled multicenter clinical study of citalopram and placebo in elderly depressed patients with and without concomitant dementia.

A total of 149 patients in 7 centers in Denmark, Norway and Sweden entered a 6-week double-blind trial intended to assess the antidepressant effect and safety of citalopram vs placebo in depressed elderly patients (65 years of age or older) who might also suffer from somatic disorders and/or senile dementia. Results of ratings on the Hamilton Rating Scale for Depression, the Montgomery-Asberg Depression Rating Scale and the Clinical Global Impression Scale provided consistent evidence that the citalopram-treated patients improved more than the placebo-treated patients. Results of ratings on the Gottfries-Bråne-Steen dementia rating scale indicated that both cognitive and emotional functioning improved significantly more in the citalopram-treated subgroup of patients with dementia than in the placebo-treated subgroup.

Aged↗
PubMed1991

1,25(OH)2-D3 is a potent regulator of interleukin-1 induced interleukin-8 expression and production.

Interleukin 8 (IL-8) is a potent leukocyte chemotactic and activating cytokine produced by keratinocytes, fibroblasts, peripheral blood monocytes (PBMC) and endothelial cells. IL-8 is believed to play an important role in the development of inflammation and is thus an obvious target for therapeutical modulation. We studied the possible effect of an endogenous immune modulator 1,25(OH)2-cholecalciferol (1,25(OH)2-D3) on the IL-1-induced IL-8-production by several types of cells. 1,25(OH)2-D3 inhibited the IL-1-alpha induced IL-8 production and mRNA expression in keratinocytes, fibroblasts and PBMC, but not in endothelial cells. Optimal vitamin concentrations varied between 10(-10) and 10(-11) M. These results suggest a potential role of this hormone in the regulation of chemotactic cytokine production.

Calcitriol↗