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Biomedical subjects

H Mikkelsen

Publications and source records attributed to H Mikkelsen.

At least 19 recordsLinked to original sources
PubMed2007

Interrelationships between colonies, biofilms, and planktonic cells of Pseudomonas aeruginosa.

Pseudomonas aeruginosa is a gram-negative bacterium and an opportunistic human pathogen that causes chronic infections in immunocompromised individuals. These infections are hard to treat, partly due to the high intrinsic resistance of the bacterium to clinically used antibiotics and partly due to the formation of antibiotic-tolerant biofilms. The three most common ways of growing bacteria in vitro are as planktonic cultures, colonies on agar plates, and biofilms in continuous-flow systems. Biofilms are known to express genes different from those of planktonic cells, and biofilm cells are generally believed to closely resemble planktonic cells in stationary phase. However, few, if any, studies have examined global gene expression in colonies. We used a proteomic approach to investigate the interrelationships between planktonic cells, colonies, and biofilms under comparable conditions. Our results show that protein profiles in colonies resemble those of planktonic cells. Furthermore, contrary to what has been reported previously, the protein profiles of biofilms were found to more closely resemble those of exponentially growing planktonic cells than those of planktonic cells in the stationary phase. These findings raise some intriguing questions about the true nature of biofilms.

Agar↗
PubMed2002

Key parameters in sludge dewatering: testing for the shear sensitivity and EPS content.

The fraction of extractable extracellular polymeric substances (EPS) and the shear sensitivity (k(ss)) are key parameters with respect to sludge dewatering, affecting the dry matter content of dewatered sludge and the dewatering rate and conditioner demand, respectively. Methods are described for determination of the two key parameters by use of the same laboratory test reactor. The implications of such characterisation with respect to dewatering are discussed based on examples of application to sludge processing and novel process development for sludge minimisation.

Polymers↗
PubMed2001

Identification and characterization of Carnobacteria isolated from fish intestine.

Eleven bacterial strains were isolated from the gastrointestinal tract of four fish species, Atlantic salmon (Salmo salar L.), Arctic charr (Salvelinus alpinus L.), Atlantic cod (Gadus morhua L.) and wolffish (Anarhichas lupus L.). All the strains were Gram-positive rods, non-sporing, catalase and oxidase-negative, able to grow at pH 9.0 but not on acetate containing media (pH < or = 5.4), and were fermentative. They had a high content of oleic acid (18:1 n-9) in cellular lipid, and were found to belong to the genus Carnobacterium by phenotypic criteria. The eleven carnobacteria strains were further identified on the basis of 16S rDNA sequence analysis and AFLP(TM) fingerprinting.

Aeromonas↗
PubMed2000

Lactic acid bacteria associated with the digestive tract of Atlantic salmon (Salmo salar L.).

The present study reports the effect of excessive handling stress and starvation on the lactic acid bacteria associated with the digestive tract of Atlantic salmon (Salmo salar L.). A relatively low population level (approximately 2 x 103 bacteria per gram wet tissue) of viable adherent heterotrophic bacteria was associated with the digestive tract (foregut, midgut and hindgut). Of the 752 bacterial isolates isolated from diet, water and the digestive tract, 201 isolates belonged to the carnobacteria. Of these isolates, one from the diet, one from the rearing water and 80 from the gastrointestinal tract, were further identified on the basis of 16S rDNA sequence analysis. All these isolates were identified as being Carnobacterium piscicola-like. Daily repeated stress and starvation of the fish over 11 d had no influence on the total culturable bacterial numbers or population level of C. piscicola associated with the digestive tract. C. piscicola-like isolates colonizing the various intestinal regions (foregut, midgut and hindgut) were also screened for their ability to produce growth inhibitory compounds active against the fish pathogen Aeromonas salmonicida. Of the 199 C. piscicola isolates tested, 139 inhibited growth of the pathogen.

Aeromonas↗
PubMed1998

Dimensional assessment of onset of action of antidepressants: a comparative study of moclobemide vs. clomipramine in depressed patients with blunted affect and psychomotor retardation.

The onset of action (during the first 2 weeks of treatment) of moclobemide (450 mg/day), a reversible MAO-A inhibitor, was compared in a double-blind, multi-center trial with clomipramine (150 mg/day) on dimensional and global depressive symptoms in 124 hospitalized patients suffering from a major depressive episode according to DSM-III-R criteria and with blunted affect and retardation. An earlier efficacy was found for moclobemide with significant treatment differences in favor of moclobemide, which were detected on negative symptoms (anhedonia, blunted affect and retardation) on days 7 and 10. The overall effect on depression at the end of the 4-week trial period was similar in both groups. However, a higher termination rate due to lack of efficacy was found with moclobemide (10 vs. 3). The tolerability was significantly better for moclobemide, as shown by the lower frequency of adverse events.

Adult↗
PubMed1996

Antidepressants and drug-metabolizing enzymes--expert group report.

Antidepressant drugs are extensively metabolized. Consequently, the biotransformation pattern of antidepressants has an important influence on their clinical properties, i.e., pharmacokinetics, toxicity, drug-drug interactions, side-effect profile and last but not least therapeutic efficacy. It was against this background that a multidisciplinary group of experts discussed the clinical relevance of the rapidly increasing body of knowledge of antidepressant-metabolizing enzymes. The variability of the response of a given individual to an antidepressant is determined genetically and by the environment. Genetic polymorphism of drug-metabolizing enzymes and inhibition by other substrates may affect the enzymatic biotransformation of antidepressants. In vitro assay techniques allow an estimation of the potential variability in clinical response to antidepressants and a reasonable prediction of the drug-drug interaction patterns. The results of in vitro tests should therefore be considered early in the development of an antidepressant as a background for designing clinical studies (treatment schedules and dosing). Physicians should have an understanding of the relevance of genetic polymorphism for clinical practice. Education is needed in order to fill the existing gaps in knowledge about antidepressant-enzyme interactions and their application in daily treatment practice. The information on potential drug interactions determined by genetic polymorphism and based on studies with enzymes should be increasingly contained in drug compendia.

Antidepressive Agents↗
PubMed1995

Therapeutic efficacy of antidepressants in agitated anxious depression--a meta-analysis of moclobemide studies.

The results of the meta-analysis of studies comparing the efficacy of moclobemide, imipramine and so-called sedative antidepressants (amitriptyline, mianserin and maprotiline) in 2416 patients are described. The results demonstrated that in agitated-anxious depressive patients (defined by HAMD factor score or HAMD item 9) a nonsedative, reversible MAO-A inhibitor moclobemide has about equal efficacy as imipramine or sedative antidepressants. All antidepressants were clearly superior to placebo, irrespective of the outcome measures applied (> 50% HAMD decrease, CGI improvement). The efficacy of antidepressants in agitated patients was unrelated to the severity of agitation and did not appear to be inferior to the efficacy in nonagitated patients. Comedication with benzodiazepines had no impact on overall efficacy of either moclobemide or other antidepressants in this patient population. Previous treatment with antidepressants, however, always negatively influenced the outcome with trial drugs, e.g., reduced their efficacy. Placebo response in agitated depressives appeared generally to be low (20-30%) and was clearly reduced with increased severity of agitation, irrespectively of how the agitation was defined.

Adult↗
PubMed1993

Effects of giving water 20-450 ml with oral diazepam premedication 1-2 h before operation.

We have studied the volume of water which should accompany diazepam 10 mg oral premedication given 1-2 h before induction of anaesthesia in 75 patients undergoing elective gynaecological laparoscopy. Twenty-five patients were given 20 ml (group A), 25 patients 150 ml (group B), and 25 patients 300-450 ml of water (group C). There were no differences between the groups in gastric fluid volume and acidity. All groups reported a reduction in thirst and dryness of the mouth after water intake, while only group B reported significant anxiolysis. Eight patients in group C experienced augmented diuresis, compared with no patients in groups A and B. We conclude that 150 ml is the ideal amount of water given with oral premedication 1-2 h before anaesthesia.

Adult↗
PubMed1992

Theoretical considerations and perspectives on the onset of action of moclobemide.

The aim of this paper is to focus on methodological problems related to clinical studies on the onset of action of antidepressants, especially moclobemide. The methodological discussion proposed focuses on: --global efficacy as a function of time; --proposals for a specific approach to the study of the onset of action; --quality of the response and onset of action; --the dimensional level and the onset of action.

Antidepressive Agents↗
PubMed1992

Efficacy and tolerability of moclobemide compared with fluvoxamine in depressive disorder (DSM III). A French/Swiss double-blind trial.

The efficacy and tolerability of moclobemide and fluvoxamine, two new types of antidepressant agents, were compared in a multicentre, double-blind prospective study of patients with a diagnosis of major depressive episode (DSM III). Patients were randomized to receive either moclobemide (150 mg) or fluvoxamine (50 mg) twice daily for 7 days, immediately following a washout period of at least 1 week. Dosages were increased where necessary on day 8, to a maximum of moclobemide 450 mg or fluvoxamine 200 mg and in most cases were maintained at these levels for the remainder of the study period (4-6 weeks). Both treatment groups showed a marked antidepressant effect. While both treatments were well tolerated, moclobemide showed a more favourable side-effect profile than fluvoxamine. Of the 126 patients eligible for evaluation, 34 withdrew from therapy, 22% in the moclobemide group and 30% in the fluvoxamine group. Adverse events were reported in 41.8% of patients treated with moclobemide compared to 60.3% of patients in the fluvoxamine group. Reports of dry mouth and other anticholinergic effects were more frequent among those treated with fluvoxamine. A greater number of gastrointestinal complaints, especially nausea, also occurred in the fluvoxamine-treated patients.

Adult↗
PubMed1988

Macrophages and mast cells in dystrophic masseter muscle: a light and electron microscopic study.

Macrophages and mast cells in masseter muscle from normal and dystrophic mice were studied by light and electron microscopy. Acid phosphatase activity and FITC-dextran were used to identify and describe macrophages. Toluidine blue was used as a marker for mast cells. In dystrophic muscle, the number of macrophages was greatly increased and they contained large amounts of phagocytozed material. In normal muscle, mast cells were rarely identified whereas dystrophic muscle contained many mast cells which were often in close contact with macrophages.

Acid Phosphatase↗
PubMed1985

Electron microscopic and histochemical studies on dystrophic masseter muscle.

Masseter muscles from normal and dystrophic mice were investigated with the electron microscope and by the use of histochemical techniques for myosin ATPase and succinic dehydrogenase activity. The observations show that the muscle fibers are severely affected in the masseter of the dystrophic mouse.

Adenosine Triphosphatases↗