| 1. |
- Nilsson, Ola, 1957, et al.
(författare)
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Praomys (Mastomys) natalensis: a model for gastric carcinoid formation.
- 1992
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Ingår i: The Yale journal of biology and medicine. - 0044-0086. ; 65:6
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Tidskriftsartikel (refereegranskat)abstract
- The gastric carcinoid tumors of Praomys (Mastomys) natalensis have been reviewed with respect to histogenesis, development, biochemistry, and morphological properties. Multicentric gastric carcinoids frequently develop in the oxyntic mucosa of aging Mastomys. The development of these tumors can be significantly enhanced by drug-induced hypergastrinemia, e.g., histamine2-receptor blockade. Spontaneous and drug-induced gastric carcinoids are endocrine in nature, as evidenced by their argyrophilic staining properties and chromogranin A content. They are also rich in histidine decarboxylase activity and produce large amounts of histamine, although other hormones, such as peptide YY and enteroglucagon, have also been demonstrated in these tumors. Ultrastructurally, gastric carcinoids are composed of tumor cells with typical secretory granules resembling those of enterochromaffin-like (ECL) cells. A close examination of the gastric carcinoids in Mastomys reveals striking similarities with gastric carcinoids developing in humans suffering from chronic atrophic gastritis type A or from the Zollinger-Ellison syndrome in combination with multiple endocrine neoplasia type 1 (MEN-1). Both these conditions are associated with hypergastrinemia and a higher risk for developing multi-centric gastric carcinoids of ECL-cell origin. The Mastomys tumor model therefore appears to be a significant experimental model in which induction and formation of gastric carcinoid tumors can be studied.
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| 2. |
- Jerkeman, Mats, et al.
(författare)
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Bacteremic and non-bacteremic febrile urinary tract infection--a review of 168 hospital-treated patients
- 1992
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Ingår i: Infection. - 1439-0973. ; 20:3, s. 143-145
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Tidskriftsartikel (refereegranskat)abstract
- Patients with febrile urinary tract infections with (80 patients) or without (88 patients) positive blood cultures were reviewed. Eighty-nine percent of the infections were community acquired. The bacteremic patients were older, Escherichia coli was the most commonly found organism in both groups. The most important finding in this study was increased frequency of resistance to three common urinary tract antibiotics (ampicillin, cephalothin and trimethoprim-sulfamethoxazole) in E. coli from patients with non-bacteremic compared with bacteremic infections. Complications occurred in 28 bacteremic and in three non-bacteremic patients. Six patients died, all with bacteremia. The significantly higher temperature at admittance among patients with gram-negative versus gram-positive bacteremic infection possibly reflects an effect by endotoxin.
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| 3. |
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| 4. |
- Nilsson, Ola, 1957, et al.
(författare)
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Presence of IGF-I in human midgut carcinoid tumours--an autocrine regulator of carcinoid tumour growth?
- 1992
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Ingår i: International journal of cancer. Journal international du cancer. - 0020-7136. ; 51:2, s. 195-203
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Tidskriftsartikel (refereegranskat)abstract
- The presence of IGF-I and IGF-I receptors in human midgut carcinoid tumours has been investigated. Using immunocytochemistry, IGF-I-positive tumour cells were demonstrated in 11/11 tumour cases studied. Labelling of consecutive sections with antibodies against IGF-I and proliferating cell nuclear antigen (PCNA)/cyclin demonstrated a co-distribution of the 2 antigens in carcinoid tumours. Extracts of tumour tissues were subjected to radioimmunoassay and shown to contain significant amounts of IGF-I. Reverse-phase HPLC of tumour extracts demonstrated a major IGF-I-immunoreactive component eluting in the position of rhIGF-I, but also 2 other more hydrophobic forms. Conditioned serum-free media from primary cultures of carcinoid tumors contained detectable amounts of IGF-I, indicating a spontaneous release of IGF-I from tumour cells into the culture medium. Levels of IGF-I in media were reduced (19%) after incubation of cultures with a somatostatin analogue for 4 days. IGF-I receptors were observed on tumour cells in 4/10 tumours by immunocytochemistry. Tumour cells with immunoreactive IGF-I receptors could be stimulated to enhanced growth, measured as an increase in DNA contents, by exogenous administration of IGF-I every 3-4 days for 2 weeks. The results show that cultured human midgut carcinoid tumours secrete IGF-I and that some of the tumours also have IGF-I receptors. We therefore suggest that IGF-I may act as an autocrine or paracrine regulator of carcinoid tumour-cell growth.
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| 5. |
- Tingström, Anders, et al.
(författare)
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Regulation of fibroblast-mediated collagen gel contraction by platelet-derived growth factor, interleukin-1 alpha and transforming growth factor-beta 1
- 1992
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Ingår i: Journal of Cell Science. - 0021-9533. ; 102:2, s. 315-322
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Tidskriftsartikel (refereegranskat)abstract
- We have examined the effects of three macrophagederived cytokines, platelet-derived growth factor (PDGF), transforming growth factor-01 (TGF-01) and interleukin-1 a (IL-la) on the contraction of collagen type I gels populated by human foreskin fibroblasts. Contraction was quantified as loss in gel weight. Both PDGF-AA and PDGF-BB were found to induce a rapid collagen-gel contraction. TGF-/J1 also stimulated gel contraction but with a delayed onset and at a slower rate than the PDGF-stimulated contraction. Rabbit polyclonal IgGs recognizing PDGF-AA and PDGF-BB, respectively, specifically inhibited the effects of the corresponding PDGF Lsoforms. However, the stimulatory effect of TGF-/S1 was not affected by any of the anti-PDGF antibodies. The ability of PDGF to stimulate contraction became less pronounced in collagen gel cultures grown in the absence of growth factors over periods of several days. Under the same conditions, the stimulatory effect of TGF-/J1 was not reduced. The reduced response to PDGF may be due to reduced tension on fibroblasts growing in collagen gels, since fibroblasts on free-floating gels showed a marked reduction in PDGF-BB-induced PDGF ^-receptor aggregates when compared to fibroblasts on attached collagen gels. LL-1 a inhibited initial collagen gel contraction, and at later stages induced a visible degradation of the collagen gels, presumably due to the generation of collagenase activity. The combination of IL-la and PDGF-BB stimulated initial collagen gel contraction, although less effectively than PDGF-BB alone. At later stages, collagen gel degradation was stimulated by this combination of cytokines. In contrast, the combination of IL-la and TGF-/51 did not stimulate collagen gel contraction, or any visible collagen gel degradation. Our data suggest that fibroblast-mediated collagen gel contraction can be modulated by cytokines via different mechanisms. Our data are of importance in the understanding of the modulatory roles of cytokines in connective tissue cell activities in inflammatory processes, such as wound healing.
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| 6. |
- Nilsson, Kenneth, 1948-
(författare)
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Radiation induced pneumonitis : clinical and experimental studies with special emphasis on the effect of smoking
- 1992
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Bronchoalveolar lavage (BAL) is an established method providing diagnostic support and evaluation of disease activity in interstitial lung disease (ILD). The aims of the present investigation were 1) to study the inflammatory response in pneumonitis evoked by irradiation. 2) to evaluate how well lung tissue inflammation is reflected in BAL findings. 3) to study the effect of smoking on radiation-induced pneumonitis.BAL was performed in 21 patients (11 smokers, 10 non-smokers) who were treated for breast cancer, stage 1 (TjMaNq) by post-surgery irradiation to an accumulated target dose of 56 Gy. It was founa that irradiation induced an alveolitis in the non-smoking patient group while the smoking patients did not differ from their smoking controls. The alveolitis in non-smokers was characterized by an increase in lymphocytes, mast cells and elevated concentrations of hyaluronan (HA), and fibronectin (FN). Three of the non-smoking patients had chest X-ray infiltrates indicating the presence of pneumonitis.An animal experimental model for radiation-induced pneumonitis and fibrosis was established in rats, allowing comparative analysis of BAL fluid and morphology. In the rat model a divergence was noted between the differential cell counts in BAL and cells observed in the interstitial tissue, which was most notable for neutrophils (PMN) and mast cells whereas there was a good correlation between HA content in BAL and HA deposition in the lung tissue. A marked infiltration of intraseptally-located mast cells occurred during the pneumonitis-phase, and this increase was paralleled by a deposition of HA in the interstitial tissue. Histochemical fixation and staining properties of the mast cells revealed that the majority of these cells were of connective tissue mast cell type (CTMC). Compound 48/80, a mast cell secretagogue, significantly altered the HA content both in BAL and in lung tissue in the irradiated animals. Regular treatment throughout the whole experimental period induced depletion of mast cell granules and a decrease in HA deposition whereas 48/80 treatment during the pneumonitis phase enhanced HA deposition.A rat model with smoke exposure was developed, and the effect of cigarette smoke on radiation-induced inflammation was studied. Rats that smoked 3 weeks prior to irradiation and continued to smoke throughout the observation period (7 weeks) had a significantly reduced inflammatory response compared to irradiated non-smoking rats. The most prominent BAL findings in the smoke-exposed rats were a decrease in PMN, mast cells and a decrease in HA.In conclusion, irradiation induces an alveolitis characterized mainly by mononuclear cells. Mast cells seem to be of importance in the remodelling of the connective tissue in the radiation-induced inflammatory response. Hyaluronan is an important component in the early connective tissue response preceding later collagen deposition, and its interstitial deposition is very well reflected in BAL. Moreover, tobacco-smoke suppresses the radiation-induced inflammation with a decreased recruitment of effector cells including mast cells.
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| 7. |
- Zätterström, Ulf K, et al.
(författare)
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Comparison of BrdUrd and [3H]TdR incorporation to estimate cell proliferation, cell loss, and potential doubling time in tumor xenografts
- 1992
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Ingår i: Cytometry. - : Wiley. - 0196-4763 .- 1097-0320. ; 13:8, s. 872-879
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Tidskriftsartikel (refereegranskat)abstract
- In this study, two different methods of estimating cell proliferation were compared: cell loss and potential growth rate of xenografted head and neck cancer grown in nude mice based on the detection of DNA incorporation of bromodeoxyuridine (BrdUrd) in one method, and [3H]thymidine ([3H]TdR) in the other. The 21-d-old xenografts were labelled in vivo, either with BrdUrd or [3H]TdR and excised at intervals during 65.5 h. In tumors containing BrdUrd, the percent labelling was measured in mid-S and mid-G1 phase windows of cytograms from bivariate DNA flow cytometry (FCM). In [3H]TdR-labelled tumors, the percent labelled mitoses (PLM) was determined by light microscopy evaluation of autoradiographs. With a computer program based on a theoretical model, the percent labelling versus time after injection was used to analyze cell cycle time, cell loss, tumor growth fraction, and potential doubling time. The values calculated from DNA incorporation with BrdUrd agreed well with those obtained from labelling with [3H]TdR, i.e., cell cycle time 2.3 vs. 2.4 d, and growth fraction 67 vs. 70%. The estimated potential doubling time was 3.1 d and cell loss factor 40% by both methods. Flow cytometry analysis of BrdUrd-labelling is considerably faster than the evaluation of [3H]TdR-labelling, and the present results provide further support for the BrdUrd labelling method as a promising alternative to the PLM method in cell cycle studies designed to evaluate the relevance of cell proliferative properties in relation to biological behavior in xenografted head and neck cancer.
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| 8. |
- Arnestad, J P, et al.
(författare)
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Isolated hyperthermic liver perfusion with cytostatic-containing perfusate activates the complement cascade.
- 1992
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Ingår i: The British journal of surgery. - 0007-1323. ; 79:9, s. 948-51
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Tidskriftsartikel (refereegranskat)abstract
- Eight patients with advanced liver malignancy undergoing isolated hyperthermic liver perfusion with melphalan and cisplatin were studied with regard to complement activation and formation of anaphylatoxins (C3a and C5a) and terminal C5b-9 complement complexes (TCCs). Blood samples for complement variables (C1-INH, C3, C4, C5, C3a, C5a and TCCs) were taken before surgery, 1 min before the start of perfusion, 1, 2 and 3 h after the start of perfusion, and 24 h after operation. Samples were drawn from the perfusate 1 h after the start of perfusion. Activation of complement was observed during perfusion. Raised plasma concentrations of C3a and TCCs were recorded and high levels of C3a and TCCs were found in the perfusate. In vitro tests indicated that melphalan and cisplatin may activate complement. This activation occurred at 37 and 42 degrees C but was more pronounced at 42 degrees C.
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| 9. |
- Augustsson, A, et al.
(författare)
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Regional distribution of melanocytic naevi in relation to sun exposure, and site-specific counts predicting total number of naevi.
- 1992
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Ingår i: Acta dermato-venereologica. - 0001-5555. ; 72:2, s. 123-7
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Tidskriftsartikel (refereegranskat)abstract
- The role of exposure to ultraviolet light in the formation of melanocytic naevi was analysed by investigating the regional naevus distribution in 310 subjects (30-50 years) from a Swedish census file. The lateral aspect of the arms and the back had the largest concentration of naevi. The mean naevus count per unit surface area was higher in intermittently exposed than in rarely exposed skin (p less than 0.001), while the lowest mean count was found in chronically exposed skin. These results support the idea that intermittent exposure to ultraviolet light has a "naevogenic" effect while chronic exposure might be protective. Dysplastic naevi had a distribution pattern quite different from common naevi. Considering the distribution pattern solely, dysplastic naevi seem to develop independently of exposure to ultraviolet light. The numbers of naevi in different skin areas were tested for their power in predicting the total body naevus count. The strongest correlations were found between total counts and counts on the anterior surface of the thighs and the lateral aspect of the arms. Counts from any of these areas will provide a practical and satisfactory estimate of the total number of naevi.
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| 10. |
- Baldetorp, Bo, et al.
(författare)
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Image cytometric DNA analysis in human breast cancer analysis may add prognostic information in diploid cases with low S-phase fraction by flow cytometry
- 1992
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Ingår i: Cytometry. - : Wiley. - 0196-4763 .- 1097-0320. ; 13:6, s. 577-585
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of DNA ploidy can be performed either with image cytometry (ICM) or flow cytometry (FCM); both methods provide independent prognostic information in primary breast cancer. The aim of the present investigation was to compare the two methods and to relate the findings to prognosis (median follow-up 42 months). Concordance in ploidy status (diploid, tetraploid, aneuploid) was obtained in 76% of the samples (168/222). When the fraction of S-phase cells (SPF) from FCM analysis was also taken into consideration, four different groups of samples were obtained (Flow I-IV), which were considered to correspond to the Auer classification (Auer I-IV) of DNA histograms obtained from image cytometry. Complete concordance between the two techniques now was 70% (155/222). Samples classified as Flow I (diploid or near-diploid with low SPF) and Auer I had a distant metastasis rate of 3/60 (5%), as compared to 62/154 (40%) for all other combinations of the Flow and Auer classifications taken together. Thus, the only findings of prognostic importance were that some samples were Flow I but not Auer I, or vice versa. These two groups represent 17 (7.7%) and 14 (6.3%), respectively, of the total number of samples, and had frequencies of distant metastasis similar to those of the other high-risk groups, namely, 7/17 and 5/14, respectively. In a multivariate analysis, flow cytometric S-phase value was a stronger prognostic factor than either the Flow and Auer classification. We conclude that when routine FCM DNA analysis is used, diploid or near-diploid samples with a low S-phase value should be reanalyzed with ICM.
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