3-D analysis of bacterial cell-(iron)mineral aggregates formed during Fe(II) oxidation by the nitrate-reducing Acidovorax sp. strain BoFeN1 using complementary microscopy tomography approaches.

The formation of cell-(iron)mineral aggregates as a consequence of bacterial iron oxidation is an environmentally widespread process with a number of implications for processes such as sorption and coprecipitation of contaminants and nutrients. Whereas the overall appearance of such aggregates is easily accessible using 2-D microscopy techniques, the 3-D and internal structure remain obscure. In this study, we examined the 3-D structure of cell-(iron)mineral aggregates formed during Fe(II) oxidation by the nitrate-reducing Acidovorax sp. strain BoFeN1 using a combination of advanced 3-D microscopy techniques. We obtained 3-D structural and chemical information on different cellular encrustation patterns at high spatial resolution (4-200 nm, depending on the method): more specifically, (1) cells free of iron minerals, (2) periplasm filled with iron minerals, (3) spike- or platelet-shaped iron mineral structures, (4) bulky structures on the cell surface, (5) extracellular iron mineral shell structures, (6) cells with iron mineral filled cytoplasm, and (7) agglomerations of extracellular globular structures. In addition to structural information, chemical nanotomography suggests a dominant role of extracellular polymeric substances (EPS) in controlling the formation of cell-(iron)mineral aggregates. Furthermore, samples in their hydrated state showed cell-(iron)mineral aggregates in pristine conditions free of preparation (i.e., drying/dehydration) artifacts. All these results were obtained using 3-D microscopy techniques such as focused ion beam (FIB)/scanning electron microscopy (SEM) tomography, transmission electron microscopy (TEM) tomography, scanning transmission (soft) X-ray microscopy (STXM) tomography, and confocal laser scanning microscopy (CLSM). It turned out that, due to the various different contrast mechanisms of the individual approaches, and due to the required sample preparation steps, only the combination of these techniques was able to provide a comprehensive understanding of structure and composition of the various Fe-precipitates and their association with bacterial cells and EPS.

Psychotherapy in dizziness: a systematic review.

BACKGROUND: About 30-50% of complex dizziness disorders are organically not sufficiently explained or related to a psychiatric disorder. Of patients with such dizziness disorders, 80% are severely impaired by dizziness in their daily and working lives; nevertheless, they are often not diagnosed or treated adequately. OBJECTIVES: This review aims to give a systematic overview of psychotherapeutic approaches and their efficacy regarding the treatment of dizziness that is medically not sufficiently explained or related to a psychiatric disorder. METHODS: A systematic literature search was conducted in Medline, PSYNDEX and PsycINFO. Included in this systematic review were (randomised) controlled trials ((R)CTs) concerning psychotherapy in patients with dizziness, medically not sufficiently explained or associated with a psychiatric disorder. If possible, Hedges' g was used to express the effect sizes (ES) of the treatment. Heterogeneity was assessed using the Q statistic. In addition, the quality of the studies was rated. RESULTS: Three (R)CTs were included. All studies used cognitive-behavioural treatment methods in combination with relaxation techniques or vestibular rehabilitation. All studies suggested that psychotherapy may provide improvement. The mean ES in the treatment groups was 0.46 (95% CI 0.05 to 0.88) for dizziness related outcome, 0.10 (-0.44 to 0.64) for anxiety and 0.17 (-0.24 to 0.58) for depression whereas in the control groups the mean dizziness related ES was -0.04 (-0.44 to 0.37), anxiety related ES was -0.03 (-0.43 to 0.38) and depression related ES was -0.02 (-0.42 to 0.38). The quality of the studies was average. Sample sizes were small, however, and there was a lack of long term studies. CONCLUSION: This systematic review provides some preliminary evidence that psychotherapy may be effective in patients with dizziness that is medically not sufficiently explained or due to a psychiatric disorder. The results should be replicated in larger samples and follow-up RCTs.

Therapeutic strategies in Friedreich's ataxia.

Friedreich's ataxia is caused by a pronounced lack of frataxin, a mitochondrial protein of not fully understood function. Lack of frataxin homologues in yeast and mice leads to increased sensitivity to oxidative stress, depletion of proteins with iron-sulfur clusters like respiratory chain complexes I-III and aconitase, and to iron accumulation in mitochondria. Similar effects have been demonstrated in human disease with increased markers of oxidative DNA damage in urine and impaired oxidative phosphorylation in in vivo exercise studies using 31 Phosphorus magnetic resonance spectroscopy (31P-MRS). Therapeutical trials mainly focus on antioxidative treatment with coenzyme Q10 or its short-chain variant idebenone. Promising effects on cardiac hypertrophy in uncontrolled preliminary studies contrast with minor effects in controlled trials and no effect of antioxidants on neurological deficits has been established. Preliminary encouraging 31P-MRS data exist for the treatment with L-carnitine but not with creatine. However, all these interventions may take effect too late in the pathogenic process. Alternative strategies aiming at an enhancement of frataxin by stem cell transplantation, gene transfer or frataxin supplementation are desirable. Additionally, more efficient biomarkers are needed to monitor treatment effects.

Phantasy therapy in psychiatry: rediscovering reality in phantasy. A special treatment for in- and outpatients in general psychiatry.

Phantasy Therapy is an interdisciplinary depth-psychologically oriented group therapy form with focus on the treatment of psychoses in acute and remission phases. A different theme is presented to the patients every week on two consecutive days (90 min per session), coherently, via various sensory channels. On the first day, the theme is concretely and operationally introduced by means of an object, transformed into movement in the broadest sense of the word, and experienced directly with the body. The first session ends with a story, usually a fairy tale or parable, so that the body experiences can be further realized symbolically at the cognitive-emotional level. The second session treats the same theme via repetition of the chosen story with the deeper transformation of symbols into color and form. The first day is jointly led by a psychotherapist and a movement/ dance therapist, the second day by a psychotherapist and an art therapist. Our approach understands therapy as a somatesthetic experience- and synthetic expression-oriented encounter with the patient via the therapist's empathic imaginative identification with the patient by means of a progressively orchestrated, positivizing, cognitive-emotional, theme-centered rapport. In this connection six therapeutic elements are of importance: theme, object, movement, fairy tale, artwork, symbol. Phantasy Therapy offers the patient creative freedom in a humorous and playful way within a certain therapeutic security (Amae principle) and contradicts several classical prejudices concerning the treatment of psychotic patients.

Electromagnetic compatibility of electronic implants--review of the literature.

The aim of the article was to provide an overview of published studies regarding the electromagnetic compatibility (EMC) of electronic implants. The available literature was sorted according to combinations of implant types and sources of interference. Several experiments concerning the susceptibility of pacemakers to mobile phones have been performed. The results of these experiments suggest measures that may be used to prevent the disturbance of pacemakers. For instance, instead of carrying the activated mobile phone in the breast pocket it is recommended that a distance of 30 cm be maintained between the pacemaker and the mobile phone, and that the mobile phone be used on the contralateral side of the pacemaker's location. Similar measures may be recommended for patients with implantable cardioverter defibrillators when using mobile phones. Patients with electronic implants should walk rapidly through anti theft-devices because some of these devices are liable to disturb implants. Patients with cardiac pacemakers should not be subjected to magnetic resonance imaging as far as possible. For a variety of combinations of implants and interference sources, e.g. cardiac pacemakers and base station antennas, no studies were found in the literature. It is strongly recommended that trials be carried out to evaluate the potential risk for patients in these settings.

Capacity of enzymes of the euphorbiacea Aleurites montana involved in CO2-fixation, compared to plants having C3-, C4- and Crassulacean acid metabolism.

Capacities of phosphoenolpyruvate carboxylase (PEP-Co), ribulose bisphosphate carboxylase (Rubisco), NADP+ malic enzyme (ME) and of malate dehydrogenase (MDH) were measured in the Euphorbiacea Aleurites montana, grown under 700 ppm CO2 for four weeks prior to enzyme extraction. For comparison Bryophyllum daigremontiana (CAM). Saccharum officinarum (C4) and Capsicum frutescens (C3) were treated in the same way. PEP-Co capacity of Aleurites was in the range of 12-, that of Capsicum approx. 26 nmol x min(-1) x mg protein(-1), without significant influence of the light period or CO2-treatment. In contrast, the activity of the enzyme from Saccharum was, depending on the duration of light, 160- respectively 96 times higher than that of the tung-oil tree. In Bryophyllum a rather low activity in the morning was increased during the day to approx. 230 nmol x min(-1) x mg protein(-1) in plants grown in the greenhouse and to approx. 115 nmol x min(-1) x mg protein(-1) in those from the growth chamber. Malate was hardly detectable in extracts of Aleurites, whereas it was high in Bryophyllum, depending on the light period. The ratio of average PEP-Co to Rub-Co capacity was high for the CAM-plant (20:1), somewhat lower for sugar cane (10:1), but almost at equality for Aleurites (0.9:1) and chilli (0.8:1). For the NADP+ malic enzyme, low capacity (20 to 28 nmol x min(-1) x mg protein(-1)) was found for Aleurites and for Capsicum, whereas it was 10 to 17 times higher in Saccharum. In Bryophyllum, the activity was up to 80 nmol x min(-1) x mg protein, dependent on light period. MDH capacity was extremely high in all plants investigated. Highest rates (10-20 micromol x min(-1) x mg protein(-1)), were obtained for Bryophyllum, followed by sugar cane and Capsicum with 5-8 micromol x min(-1) x mg protein(-1). Again, the lowest capacity was found in extracts of Aleurites with approx. 1.3 to 1.6 micromol x min(-1) x m protein(-1). Thus, in Aleurites montana no indication for C4- or Crassulacean acid metabolism was obtained. Therefore, the earlier observed very efficient uptake of CO2 cannot be explained by a high expression of the PEP-Co protein, known to occur in CAM- and C4-plants.

Seeds of Trichosanthes kirilowii, an energy-rich diet.

The kernels of Trichosanthes kirilowii seeds contain a green oil which makes up for 62% of their dry matter. This oil consists up to 95% of triglycerides, 2% of glycolipids, 1.3% of phospholipids and 1.8% of chlorophylls. As fatty acid components the triglycerides, glycolipids and phospholipids contain the unsaturated fatty acids linoleic and oleic acid and the saturated palmitic acid. In the triglycerides 19% of the C18:3 acid occur with the configuration delta9 cis, delta11 trans, delta13 cis. This acid is called trichosanic acid and is absent in glycolipids and phospholipids which contain instead another C18:3 fatty acid, which has conjugated double bounds and occurs with an amount of 21% and 3%, respectively. Typically, these oil seeds contain in addition up to 30% of their dry matter proteins and up to 2.5% mono- and oligosaccharides. The monosaccharides consist of rhamnose, galactose and glucose and the oligosaccharides represent a mixture of tri- and tetrasaccharides.

The role of phosphatidylglycerol as a functional effector and membrane anchor of the D1-core peptide from photosystem II-particles of the cyanobacterium Oscillatoria chalybea.

The intrinsic polypeptide D1, isolated from photosystem (PS) II-particles of the cyanobacterium Oscillatoria chalybea, was obtained by electroelution and fractionated extraction with organic solvents. Purification was demonstrated by Western blotting and amino acid sequencing. By carrying out D1-immunization in rabbits a polyclonal monospecific D1-antiserum was obtained. For the qualitative characterization of D1 as a lipid-binding peptide, the effect of the lipids phosphatidylglycerol (PG), monogalactosyldiacylglyceride (MGDG) and phosphatidylcholine (PC) on PSII-oxygen evolution was analysed in reconstitution experiments. In these experiments purified photosystem II (PSII)-particle preparations were treated with the enzyme phospholipase A2 and supplemented with lipid emulsions. We were able to show that the inhibition of electron transport, as the consequence of this lipase treatment, was only relieved, if phosphatidylglycerol was added to the preparation. A model was proposed, in which phosphatidylglycerol is a functional effector for the optimal conformation of D1 in the PSII core complex. Phosphatidylglycerol molecules are unusually tightly bound to the D1 peptide by hydrophobic interactions. A covalent binding seems not probable. The localisation of phosphatidylglycerol binding sites was found by trypsin treatment of D1 and analysis of the obtained oligopeptides with HPLC and immunoblotting. The binding sites could be confined to the hydrophobic amino acid section between arginine 27 and arginine 225, which is known to be the membrane anchor of D1. This has led us to the conclusion that the phospholipid phosphatidylglycerol plays an important role for anchoring the D1-peptide and for its orientation in the thylakoid membrane. Phosphatidylglycerol with its high amount of palmitic acid has in prokaryotic cyanobacteria apparently a role in stabilization and orientation. The high turn-over of D1 and the spatial separation of the synthesis- and incorporation-site in the membrane, developed during evolution in eukaryotic organisms, might have changed the requirement on the mobility and the orientation of D1 in photosynthetic membranes.

Design and synthesis of potent and highly selective thrombin inhibitors.

Thrombin, a serine protease, plays a central role in the initiation and propagation of thrombotic events. An extensive search for new thrombin inhibitors was performed, using an unconventional approach. Screening of small basic molecules for binding in the recognition pocket of thrombin led to the discovery of (aminoiminomethyl)piperidine (amidinopiperidine) as a weak, but intrinsically selective, thrombin inhibitor. Elaboration of this molecule provided compounds which inhibit thrombin with Ki's in the range of 20-50 nM and with selectivities of 1000-4000 against trypsin. These inhibitor compounds show a new and unexpected binding mode to thrombin. Modification of the central building block and then of one of the hydrophobic substituents led to the discovery of a new family of thrombin inhibitors which has reverted to the former binding mode to thrombin. This last class of compounds shows inhibitory activities in the picomolar range, low toxicity, and a short plasma half life which favors its use for an intravenous application. From this series of thrombin inhibitors, 19f(Ro 46-6240) was selected for clinical development as an antithrombotic agent for intravenous administration.

Ro 42-1611 (arteflene), a new effective antimalarial: chemical structure and biological activity.

The discovery of the natural peroxides qinghaosu (arteannuin A, artemisinin) (1) and yingzhaosu A (3) from traditional Chinese herbal medicines was a major advance in the search for new antimalarials (Fig. 1). Whereas qinghaosu can be produced from natural sources and has been well studied, yingzhaosu A has never been available for full evaluation as anti-malarial. We have designed a synthesis of the novel ring system present in yingzhaosu A, the 2,3-dioxabicyclo[3.3.1]nonane and prepared a series of yingzhaosu A analogues which were tested against Plasmodium berghei in mice. Structure-activity rules could be established and used for lead optimization. The best anti-malarial activity was observed for analogues having a keto group within the ring system and an aliphatic or aromatic lipophilic tail as ring substituent. The optimized analogues possessed activity comparable to qinghaosu. In spite of the presence of a peroxide ring, the new compounds were chemically stable against common reagents. In contrast to qinghaosu and its derivatives, they were also stable against hydrolytic decomposition and could therefore be expected to show improved pharmacokinetic properties. As one of the best compounds, Ro 42-1611 (arteflene) (26n, Fig. 2) was selected for detailed preclinical evaluation. Ro 42-1611 (arteflene) was found negative in a battery of mutagenicity tests. It had low acute toxicity after oral or subcutaneous administration. In a 4-week oral tolerance study in rats, doses of up to 400 mg/kg/day were well tolerated.(ABSTRACT TRUNCATED AT 250 WORDS)

Repeated batch cultivation of rBHK cells on Cytodex 3 microcarriers: antithrombin III, amino acid, and fatty acid metabolic quotients.

Anchorage-dependent human antithrombin III-producing recombinant baby hamster kidney (rBHK) cells were cultivated on Cytodex 3 microcarriers in repeated batch mode. During a 3-month experiment four different low-serum (0.025% fetal bovine serum) or serum-free medium formulations were evaluated for (a) the initial growth phase of cells and (b) the subsequent production phase, whereby two free fatty acid (FFA) supplements were examined with respect to their growth-promoting and product-formation-enhancing properties. Selected nutrient and (by)product consumption and production rates (including those for antithrombin III, amino acids, and fatty acids) are reported. The calculated metabolic quotients reflect the prevailing slow growth conditions (mu approx. 0.06 day-1) associated with microcarrier cultures. Specific antithrombin III productivities vary significantly as a function of the feed medium supplementation with FFA.

Extra- and intracellular metabolite concentrations for murine hybridoma cells.

Intra- and extracellular metabolite concentrations were determined for hybridoma cells grown in tissue culture flasks in batch culture. Significant differences were found for intracellular lactate and amino acid concentrations depending on the culture medium. AB2-143.2 cells cultivated in Dulbecco's modified Eagle's (DME) medium supplemented with 50 mM lactate exhibited intracellular lactate and glutamine levels of 40 mM and 4 mM, respectively, whereas cells grown in standard DME medium had low intracellular glutamine and 20 mM lactate concentrations. For cells cultivated in medium supplemented with 6 mM pyruvate, intracellular lactate levels were estimated at approx. 40 mM, but these cells also showed an increased intracellular alanine concentration of 22 mM. The higher alanine pools probably result from increased transamination of pyruvate under these conditions.

Treatment of chancroid, 1989.

Since recommendations for the treatment of chancroid were made in 1985, in vitro and in vivo data indicate that the two drugs recommended, erythromycin (500 mg four times a day for 7 days) and ceftriaxone (250 mg intramuscularly in a single dose), remain effective. The alternative therapies of trimethoprim-sulfamethoxazole (160/800 mg twice a day for 7 days) and amoxicillin-clavulanic acid (500/125 mg three times a day for 7 days) also appear to be effective, although there has been little experience with these drugs in the United States. Single-dose trimethoprim-sulfamethoxazole (640/3,200 mg) now lacks the efficacy of other regimens. The experience with ciprofloxacin (500 mg twice a day for 3 days) has been favorable, and other quinolones may prove useful. Concurrent infection with human immunodeficiency virus appears to result in an increased rate of failure of treatment for chancroid, and such cases may require more prolonged therapy.

Oral nifedipine vs oral clonidine in the treatment of urgent hypertension.

Fifty-one patients with urgent hypertension were treated in the emergency department with either oral nifedipine or oral clonidine in a randomized double-blind prospective study. Nifedipine was administered as a single dose of 20 mg. Clonidine was administered as an initial dose of 0.1 mg with hourly doses of 0.1 mg. Nifedipine was successful in reducing diastolic blood pressure in 83% of the patients within 45 minutes and in 96% of the patients within two hours, with a mean reduction in systolic blood pressure of 47 mm Hg and diastolic blood pressure of 29 mm Hg. Thirty percent of those who initially responded to nifedipine experienced a subsequent increase in diastolic blood pressure to pretreatment levels within three hours. Clonidine was successful in reducing diastolic blood pressure in 79% of the patients within four hours, with a mean reduction in systolic blood pressure of 51 mm Hg and diastolic blood pressure of 30 mm Hg. Our results indicate that both nifedipine and clonidine are safe and effective in the treatment of urgent hypertension. Nifedipine had a much more rapid onset of action with a greater initial success rate, and it was free from the sedative side effects of clonidine. We believe that either nifedipine or clonidine may be used as first-line therapy in the treatment of urgent hypertension.

Endocrine function after bone marrow transplantation without the use of preparative total body irradiation.

Ten children who underwent allogeneic (n = 5) or autologous (n = 5) bone marrow transplantation (BMT) for chronic myelogenous leukaemia (n = 2), acute lymphoblastic leukaemia (n = 1), acute myelogenous leukaemia (n = 2), severe aplastic anaemia (n = 2), malignant histiocytosis (n = 1), neuroblastoma (n = 1) and teratoma (n = 1) were assessed for endocrinological function. Transplant preparative regimens consisted of high-dose cyclophosphamide, high-dose cyclophosphamide in combination with high-dose busulphan, high-dose melphalan as well as BACT (BCNU, cytarabine, cyclophosphamide and 6-thioguanine) chemotherapy. None of the patients received total body irradiation (TBI). Median survival following BMT was 37 months (range 7-115). Growth hormone deficiency was present in only one patient; none of the patients had abnormal thyroid or adrenocortical function. This is in contrast to previous reports in which growth hormone deficiency and abnormal thyroid and adrenocortical function occurred in a much higher percentage of patients after BMT conditioned with TBI.

Prostacyclin (PGI2) induces rapid depletion of cyclic AMP levels in brain nuclei of rats.

Intravenous injection of prostacyclin (100 micrograms/kg) in rats resulted in a decrease of systolic blood pressure within 2 minutes. Concentrations of cAMP in 15 brain regions and nuclei were determined by radioimmunoassay. In lower brain stem nuclei, such as the nucleus of the solitary tract and the lateral reticular nucleus (A1 and C1 catecholaminergic cell groups) cAMP levels were depleted significantly, while in others, including the locus coeruleus and the periaqueductal central gray, cAMP levels did not show any alterations. Levels of cAMP were also depleted in some of the hypothalamic nuclei (periventricular, anterior hypothalamic, ventromedial), and in cerebral cortical areas. Lowered cAMP levels in brain areas might indicate lower cellular activity in cells participating in baroreceptor control mechanisms.

Susceptibility of the Lyme disease spirochete to seven antimicrobial agents.

The antimicrobial susceptibility of five Lyme disease spirochete strains (two human and three tick isolates) was determined. A macrodilution broth technique was used to determine on three separate test occasions the minimal inhibitory concentrations (MICs) of seven antibiotics. The Lyme disease spirochete was most susceptible to erythromycin with a MIC of less than or equal to 0.06 micrograms/ml. The spirochete was also found to be susceptible to minocycline, ampicillin, doxycycline, and tetracycline-HCL with respective mean MICs of less than or equal to 0.13, less than or equal to 0.25, less than or equal to 0.63, and less than or equal to 0.79 micrograms/ml. The spirochete was moderately susceptible to penicillin G with a mean MIC of 0.93 micrograms/ml. All strains were resistant to rifampin at the highest concentration tested (16.0 micrograms/ml).

Early arteriosclerotic changes of the carotid artery wall induced by electrostimulation. A study by scanning and transmission electron microscopy.

Using the method described by Betz and Schlote, 1979, it is possible to produce local smooth muscle cell proliferation in the intima of arterial walls by electrostimulation. If local electrostimulation is combined with a high cholesterol diet, atheromatous plaques arise at the anodal region of the stimulation electrodes. This is achieved by implanting a cuff around the common carotid artery of rabbits. By means of the electrodes which are situated in the cuff, DC-impulses are applied. The advantages of the described method are the following: the site of alteration can be determined, the stimulation intensity can be exactly adjusted and an initially induced coarse endothelial injury can be avoided. In this study the very first morphological changes have been observed by scanning and transmission electron microscopy. After an initial enlargement of the subendothelial space a migration of myocytes into this space is seen followed by a transformation of smooth muscle cells into modified cells. They develop a more active metabolism, undergo mitosis and produce proliferations after 4 days of stimulation. The development of the plaques shows a striking agreement with the results of other authors, although the used methods are completely different. Therefore, it can be assumed that the walls of arteries respond to various types of alterations with an unspecific and uniform reaction. Concerning our results, at least, an endothelial desquamation is not a prerequisite for a proliferative reaction of arterial smooth muscle cells. It can be concluded that, at the beginning of the arteriosclerotic development, a functional event predominates, which depends in our experiments on the electrical charge applied to the artery wall at the anode. Because of its functional character, this triggering mechanism cannot be investigated by morphological methods alone.