Apmis

Nilsson, Ola

doi: 10.1111/j.1699-0463.1996.tb04902.xpmid: 8920800

Gastrointestinal carcinoids are a heterogeneous group of hormone‐producing tumours originating from the diffuse neuroendocrine system of the gastrointestinal mucosa. Recent studies have shown that carcinoid tumours share many of the morphological, biochemical and functional properties of the neuroendocrine cells from which they are derived. Identification of these properties, e.g. specific hormone production, contents of secretory granules or specific proteins of the secretory granules/vesicles, forms the basis for the diagnosis of carcinoid tumours. Classification of gastrointestinal carcinoids is based on the clinical settings under which the tumours develop, tumour site, as well as the morphological and biochemical characteristics of the tumour. Although generally considered a low grade malignancy, carcinoid tumours show a highly variable clinical course from benign tumours discovered incidentally to highly malignant tumours presenting with disseminated spread and disabling hormonal symptoms. Precise knowledge of tumour location, size and stage, as well as growth pattern and hormonal syndromes, is necessary to predict the behaviour of the tumour and optimise treatment.

Fagerheim, Ingrid; Lingaas, Egil

doi: 10.1111/j.1699-0463.1996.tb04903.xpmid: 8920801

Human polymorphonuclear neutrophils were exposed to direct output current of 3 or 5 mA at either 300 or 500 V for 1 h in the presence and absence of iron. The current density was 25 or 40 nA/cm2. The formation of free oxygen radicals was measured as breakdown products from deoxyribose and methional. The cells were shown to generate oxygen radicals on electrical stimulation. A physiological concentration of iron enhanced radical formation, but OH was also formed in the absence of added iron. The most pronounced stimulation was seen at output current 5 mA and 500 V

Farinelli, Andrea; Setti, Maurizio; Puppo, Francesco; Scudeletti, Marco; Martini, Daniele; Balestra, Vincenzo; Indiveri, Francesco

doi: 10.1111/j.1699-0463.1996.tb04904.xpmid: 8920802

Although measurement of chemiluminescence has become a widespread tool in the study of phagocytosis of peripheral neutrophils, several problems linked to spontaneous fluctuation in chemiluminescence and the number of variables involved have occasionally either limited its usefulness for clinical and experimental purposes or compelled operators to take particular care when using the technique. In the present paper, sources of variability are investigated and most of the parameters involved are thoroughly analysed and step‐by‐step normalised. A stochastic calibration procedure for validation of the method is applied and a monofunctional test protocol for quantitative evaluation of plasma opsonizing activity in whole blood chemiluminescence is suggested. With regard to the goal of proposing a reverse monofunctional test, we discuss the reasons why further studies aimed at standardised evaluation of the cellular components are needed.

Chen, Libing; Nordlind, Klas; Liden, Sture; Sticherling, Michael

doi: 10.1111/j.1699-0463.1996.tb04905.xpmid: 8920803

Heavy metal‐induced contact eczematous human skin reactions to cobalt chloride and mercuric chloride were investigated for immunoreactivity to interleukin‐8 (IL‐8), by using an indirect immunoperox‐idase staining technique. There was suprabasal epidermal staining for IL‐8, with a decrease in the vicinity of areas with parakeratotic epithelium. However, in the immediate vicinity of a vesicular formation, intense staining of some apically situated keratinocytes was found. In addition, increased immunoreactivity over the acrosyringial area compared with the surrounding epidermis was obtained. These findings indicate an increased synthesis of keratinocyte IL‐8 in contact eczematous skin.

Aksnes, Jon; Eide, Tor J.; Nordstrand, Kenneth

doi: 10.1111/j.1699-0463.1996.tb04906.xpmid: 8920804

We have demonstrated organ damage after long‐term administration of lipid‐based parenteral nutrition, possibly initiated by intravascular pooling of lipid and phagocytes, in both rats and pigs. To evaluate whether accumulation of lipid could simply be caused by mechanical filtration, a comparative study of three separate capillary beds was performed. Rats were given lipid emulsion (n = 5) or isotonic saline (n=4) through central venous catheters for 3 weeks. Using both light and electron microscopy, lipid accumulation and structural changes in the rat myocard were compared to those in the lung and liver. The study provides evidence that within myocardial capillaries both peripheral blood monocytes and endothelial cells performed phagocytosis of lipid droplets following administration of lipid emulsion, but no large‐scale intravascular pooling of lipid resulted. Morphometry of the myocard detected no lipid increase in the myocytes from the rats given lipid emulsion compared with controls and in neither were there any stigmata of vasculitis or myocardial damage, in contrast to the lung and liver, where intravascular pooling of lipid and phagocytes was seen. This indicates that phagocytosis was an important mechanism involved in entrapment and elimination of lipid.

Berge, V.; Berge, K. E.; Johnson, E.

doi: 10.1111/j.1699-0463.1996.tb04907.xpmid: 8920805

In this study we demonstrate that human endothelial cells (EC) synthesize mRNA for vitronectin by using techniques based on reverse transcriptase (RT) reaction and polymerase chain reaction (PCR). The identification of vitronectin mRNA, shown by sequence analysis of PCR‐amplified RT product of RNA extracted from EC, clearly demonstrates that these cells synthesize mRNA for vitronection. We further investigated whether vitronectin in serum‐free EC cultures regulates the net expression of the terminal complement pathway, measured as the terminal complement complex (TCC) bound to co‐cultured agarose beads which activate the alternative pathway. Presence of polyclonal F(ab‘)2 anti‐human vitronectin (VN) antibodies, regardless of concentration (10–80 μg/ml), significantly reduced the binding of monoclonal anti‐C3c antibodies to co‐cultured beads, whereas the binding of monoclonal anti‐TCC antibodies was unaltered or significantly increased compared with controls. Despite some interexperimental variation in the results, addition of vitronectin (10–80 μg/ml) to the EC resulted in an inversely related pattern compared with experiments using anti‐VN antibodies. The binding indices of anti‐C3c are comparable to the controls. On the other hand, there is a steady concentration‐dependent (10–80 μg of vitronectin added) reduction in binding of anti‐TCC up to approximately 60%. The results indicate that vitronectin regulates the expression of synthezised and surface‐bound TCC in serum‐free EC cultures, comparable to previous findings in serum.

Schumacher, H.; Skibsted, U.; Skov, R.; Scheibel, J.

doi: 10.1111/j.1699-0463.1996.tb04908.xpmid: 8920806

In order to characterize cefuroxime resistance in Escherichia coli 22 clinical isolates were investigated for susceptibility to different β‐lactam antibiotics and ciprofloxacin. The production of β‐lactamases, the pattern of the major outer membrane proteins (OMPs), and the plasmid profiles were determined for these isolates. Ten of the isolates were resistant to ceftazidime, two to cefotaxime, and none was resistant to imipenem or ciprofloxacin. The dominating resistance mechanism was hyperproduction of the chromosomally encoded β‐lactamase to some extent accompanied by alterations of the OMP's. Two isolates with low ampicillin MIOs seemed solely to have alteration of the OMPs. None of the isolates produced plasmid‐mediated extended‐spectrum p‐lactamases. In addition, the prevalence of cefuroxime resistance was investigated. The prevalence as attained in 8704 clinical isolates of E. coli collected from Copenhagen County during a 5‐year period (1990–1994) was 4.4%, but there was considerable variation among specimens from different sites of the body. Isolates from blood were much less resistant (2.5%) than isolates from the respiratory tract (9.7%))

Haug, C. J.; MÜLler, F.; Rollag, H.; Aukrust, P.; DegrÉ, M.; FrØLand, S. S.

doi: 10.1111/j.1699-0463.1996.tb04909.xpmid: 8920807

The active metabolite of vitamin D, 1,25‐dihydroxyvitamin D3 (1,25D), has been shown to induce monocyte‐to‐macrophage maturation in vitro as well as monocytic differentiation of bone marrow precursors and monocytic leukaemic cell lines. In this study we assessed whether 1,25D could improve the maturation defect we have previously demonstrated in monocytes from AIDS patients. In vitro growth and maturation of monocytes from 10 controls, 15 asymptomatic HIV positives (CDC group II or III) and 13 symptomatic HIV positives (CDC group IV) was examined by assessing cellular morphology, differentiation, adherence and protein content. Cells were cultured for 10 days with or without addition of 1,25D at a concentration of 100 pg/ml. In addition, patients were monitored clinically and by immunological parameters and HIV p24 antigen in serum. The present study showed that addition of 1,25D significantly improved the growth and maturation in both patient and control groups. There was a significant negative correlation between response to 1,25D and CD4+ lymphocyte count in blood in HIV‐infected patients. A greater response to 1,25D was seen in monocytes from patients with advanced immunodeficiency and symptomatic disease than in monocytes from asymptomatic patients. However, in the most advanced cases of HIV infection with serious ongoing opportunistic infections the response to 1,25D was very poor, possibly reflecting profound and incorrigible dysfunction of monocytes

Poulsen, Rikke Lykke; Knudsen, Jenny Dahl; Petersen, Mette Barendorff; Fuursted, Kurt; Espersen, Frank; Frimodt‐MØLler, Niels

doi: 10.1111/j.1699-0463.1996.tb04910.xpmid: 8920808

Four different diffusion tests used to detect penicillin resistance in Streptococcus pneumoniae were evaluated for 34 penicillin‐susceptible pneumococci (MIC <0.1 μg/ml), 35 intermediate penicillin‐resistant (MIC 0.1–1.0 μg/ml) and 23 penicillin‐resistant strains (MIC >2 μg/ml). The 1 μg oxacillin disk from AB Biodisk, the 1 μg oxacillin Neo‐Sensitabs from Rosco, the 5 μg penicillin Low Neo‐Sensitabs and the penicillin E test were tested on Mueller‐Hinton blood agar, PDM Antibiotic Sensitivity Medium II supplemented with blood, and Danish Blood Agar. MICs obtained by the agar dilution method were used as reference. The 1 μg oxacillin AB Biodisk was able to separate all the penicillin‐susceptible pneumococci correctly from those with reduced penicillin susceptibility (MIC 0.1 μg/ml), whereas use of the 1 μg oxacillin Neo‐Sensitabs resulted in high frequencies (14–29%) of intermediate penicillin‐resistant strains interpreted as penicillin susceptible. The 5 μg penicillin Low Neo‐Sensitabs proved completely useless for detecting penicillin resistance in pneumococci. High rates of agreement (82–93%) were found between the penicillin E test and the reference MIC determination method on all the tested media.

Ejlertsen, T.; Skov, R.

doi: 10.1111/j.1699-0463.1996.tb04911.xpmid: 8920809

Two distinct β‐lactamases have been isolated from Moraxella catarrhalis: the stronger acting BRO‐1 enzyme and the weaker acting BRO‐2. Several reports have noted an effect of penicillin and ampicillin on infections caused by M. catarrhalis in spite of the presence of β‐lactamase production. The purpose of this work was to characterize the β‐lactamases of M. catarrhalis isolated from Danish children regarding type and susceptibility, and to relate these findings to the eradication of β‐lactamases‐producing strains by use of antibiotic treatment with penicillin or ampicillin. MICs for penicillin V, ampicillin, cefuroxime and amoxicillin/clavulanic acid (2:1) were determined in 70 strains of M. catarrhalis: 46 strains from children with lower respiratory tract infection (LRTI) and 24 strains from respiratory healthy children, β‐lactamase production was found in 59 strains. The BRO‐1 enzyme was identified by isoelectric focusing in 55 strains (93.2%) and BRO‐2 in 3 strains (5.1%); in 1 strain no isoelectric bands were produced. All strains were susceptible to cefuroxime and amoxicillin/clavulanic acid, and non‐β‐lactamase‐producing strains were susceptible to penicillin and ampicillin. For the β‐lactamase‐producing strains, MIC50 of penicillin was 8.0 μg/ml, while MIC50 of ampicillin was 1.0 μg/ml and MIC90 of ampicillin was 2.0 μg/ml. M. catarrhalis was more often eradicated from the children who received antibiotic treatment with penicillin or ampicillin than from those who did not receive any treatment, indicating an in vivo effect of penicillin and ampicillin in spite of the β‐lactamase production.