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1.
Neuroimage ; 184: 687-696, 2019 01 01.
Article in English | MEDLINE | ID: mdl-30287300

ABSTRACT

Being in control of one's emotions is not only desirable in many everyday situations but is also a great challenge in a variety of mental disorders. Successful intentional emotion regulation is related to down-regulation of amygdala activity. Training mental interventions supported by neurofeedback of one's own amygdala activity using real-time (rt-)fMRI might be beneficial for mental health and well-being. Rt-fMRI guided amygdala-downregulation using cognitive interventions such as a "reality check", however, have not been well-investigated. Fifteen healthy subjects underwent four rt-fMRI sessions with neurofeedback of their own amygdala activity while applying a reality check as an emotion regulation strategy in order to down-regulate their amygdala signal during a stimulation with emotional pictures. The Control group comprised of eleven subjects also trained emotion regulation but without obtaining feedback. We hypothesized more prominent down-regulation of amygdala activity at the end of the training in the Feedback group. We investigated effects over time and between groups and further task specific connectivity of the amygdala by using psychophysiological interaction analyses. Four weekly amygdala-based feedback sessions resulted in significantly decreased amygdala activity (p = 0.003, d = 0.93), also compared to the Control group (p = 0.014, d = 1.12). Task specific connectivity of the amygdala with the anterior cingulate cortex, hippocampus and distinct prefrontal areas was increased in the Feedback group. Training of emotion regulation supported by rt-fMRI neurofeedback resulted in a prominent amygdala down-regulation compared to training without feedback. The finding implicates successful emotion regulation, compliant with emotion control models, through an easily applicable reality check strategy. Rt-fMRI neurofeedback may support emotion regulation learning and bears clinical potential for psychotherapy.


Subject(s)
Amygdala/physiology , Emotions/physiology , Neurofeedback/methods , Self-Control/psychology , Adult , Brain Mapping/methods , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Young Adult
2.
RSC Adv ; 8(28): 15632-15640, 2018 Apr 23.
Article in English | MEDLINE | ID: mdl-35539455

ABSTRACT

Coordination complexes [M(O2CCH2OC2H4OMe)2] (M = Co, 4; M = Mn, 5) are accessible by the anion exchange reaction between the corresponding metal acetates [M(OAc)2(H2O)4] (M = Co, 1; M = Mn, 2) and the carboxylic acid HO2CCH2OC2H4OMe (3). IR spectroscopy confirms the chelating or µ-bridging binding mode of the carboxylato ligands to M(ii). The molecular structure of 5 in the solid state confirms a distorted octahedral arrangement at Mn(ii), setup by the two carboxylato ligands including their α-ether oxygen atoms, resulting in an overall two-dimensional coordination network. The thermal decomposition behavior of 4 and 5 was studied by TG-MS, revealing that decarboxylation occurs initially giving [M(CH2OC2H4OMe)2], which further decomposes by M-C, C-O and C-C bond cleavages. Complexes 4 and 5 were used as CCVD (combustion chemical vapour deposition) precursors for the deposition of Co3O4, crystalline Mn3O4 and amorphous Mn2O3 thin films on silicon and glass substrates. The deposition experiments were carried out using three different precursor solutions (0.4, 0.6 and 0.8 M) at 400 °C. Depending on the precursor concentration, particulated layers were obtained as evidenced by SEM. The layer thicknesses range from 32 to 170 nm. The rms roughness of the respective films was determined by AFM, displaying that the higher the precursor concentration, the rougher the Co3O4 surface is (17.4-43.8 nm), while the manganese oxide films are almost similar (6.2-9.8 nm).

3.
Clin Radiol ; 70(6): 622-9, 2015 Jun.
Article in English | MEDLINE | ID: mdl-25819627

ABSTRACT

AIM: To evaluate the incidence and clinical relevance of extravascular incidental findings (EVIFs) in CT angiography of the abdominal aorta and lower extremities (run-off CTA) in patients presenting with acute limb ischaemia (ALI). MATERIALS AND METHODS: In this institutional review board-approved, retrospective study, 141 run-off CTA examinations conducted between 2005 and 2013 of patients (67 women, mean age 80 years; 74 men, mean age 69 years) presenting with clinical symptoms of ALI were re-evaluated by two radiologists (2 and 7 years of experience in interpreting run-off CTA). Imaging was conducted using 16- and 64-section CT systems. Image acquisition ranged from the costodiaphragmatic recess to the forefoot. The medical history form of each patient served as the standard of reference for assessment of incidence of EVIFs. CT morphology was assessed to assign EVIFs to one of three categories of clinical relevance: (I) immediate, (II) potential, and (III) no clinical relevance. RESULTS: Thirty-eight patients had category I findings, including four patients (2.8%) with previously unknown malignancy and 67 patients with category II EVIFs. In total 473 extravascular EVIFs were found in 141 patients: 52 category I, 163 category II and 258 category III. CONCLUSION: EVIFs with immediate clinical relevance are very common in run-off CTA in patients presenting with acute peripheral artery disease. Therefore, it is important to evaluate all body regions included in a CT examination carefully, even if the clinical focus is on vascular evaluation. The adequate classification of these EVIFs is required to avoid possible unnecessary diagnostic work-up with associated risks and costs.


Subject(s)
Incidental Findings , Ischemia/diagnostic imaging , Lower Extremity/blood supply , Acute Disease , Aged , Aged, 80 and over , Aorta, Abdominal/diagnostic imaging , Female , Humans , Male , Retrospective Studies , Tomography, X-Ray Computed
4.
Br J Anaesth ; 112(2): 265-71, 2014 Feb.
Article in English | MEDLINE | ID: mdl-24185609

ABSTRACT

BACKGROUND: Positioning central venous catheters (CVCs) in the proper part of the superior vena cava (SVC) is difficult. The aim of this exploratory study was to analyse topographic relationships of the extrapericardial SVC using chest X-ray (CXR) and computed tomography (CT). This included an appraisal of rules for optimal CVC tip placement. METHODS: We retrospectively evaluated 100 patients with CVCs who underwent bedside CXR and CT on the same day. Distances between the sternoclavicular joint (SCJ), tracheal carina, SVC origin, pericardial reflection, and CVC tip were analysed on CT and, if visible, on CXR. These measurements served to locate the extrapericardial SVC in relation to anatomical landmarks. Different strategies for CVC tip positioning were evaluated. RESULTS: The mean (standard deviation) extrapericardial length of the SVC was 26 (12) mm. The average position of the pericardial reflection was 5 mm below the carina (range, 29 mm below to 25 mm above). In our patient population, the best results in terms of tip positions in the extrapericardial SVC would have been achieved by using 85% of the SCJ-to-carina distance (in 86%) or by positioning the CVC tip 9 mm above the carina (in 84% of patients). CONCLUSIONS: The extrapericardial part of the SVC varies considerably in length and position, and rules of thumb based on anatomical landmarks should be used cautiously. In our series, using 85% of the SCJ-to-carina distance or placing the CVC tip 9 mm above the carina would have resulted in a high percentage of positions in the extrapericardial SVC.


Subject(s)
Catheterization, Central Venous/methods , Central Venous Catheters , Radiography, Thoracic/methods , Tomography, X-Ray Computed/methods , Adolescent , Adult , Aged , Aged, 80 and over , Contrast Media/administration & dosage , Female , Humans , Image Processing, Computer-Assisted/methods , Iohexol/administration & dosage , Iohexol/analogs & derivatives , Male , Middle Aged , Pericardium/diagnostic imaging , Radiographic Image Enhancement/methods , Retrospective Studies , Trachea/diagnostic imaging , Vena Cava, Superior/diagnostic imaging , Young Adult
5.
Acta Neurochir (Wien) ; 155(12): 2333-8, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24136677

ABSTRACT

BACKGROUND: Surgery of lumbar disc herniations is one of the most common neurosurgical procedures. New surgical approaches and techniques are constantly evolving. We present our long-term follow-up results comparing standard open microdiscectomy (SOMD) and minimal access microdiscectomy (MAMD) for single-level lumbar disc herniations. METHODS: Patients were randomized in two groups receiving either MAMD or SOMD. Physical and mental health and pain relief were assessed (ODI, SF-36 questionnaire, VAS leg and back pain). In addition, all patients received MR imaging for morphological evaluation of postoperative peridural scar tissue formation. RESULTS: Of the 60 initial patients (SOMD: 30 pts, MAMD: 30 pts), 38 were available for long-term follow-up. Mean follow-up time was 33 months. Long-term follow-up revealed significant postoperative pain relief in both groups. Good to excellent results concerning physical and mental health and pain relief were achieved in both groups. Significantly less peridural scar tissue formation was observed in the MAMD patients, but without clinical impact. CONCLUSION: MAMD is a feasible alternative to the standard open approach. Both groups show significant and long-lasting pain relief and good to excellent results regarding health-related quality of life. Congruent to our short-term results, we observed slightly but not statistically significant better clinical results in the MAMD group when compared to the SOMD group.


Subject(s)
Diskectomy , Herniorrhaphy/methods , Intervertebral Disc Displacement , Lumbar Vertebrae/surgery , Minimally Invasive Surgical Procedures , Adult , Back Pain/etiology , Diskectomy/methods , Female , Follow-Up Studies , Hernia/complications , Humans , Male , Microsurgery/methods , Middle Aged , Treatment Outcome , Young Adult
6.
J Appl Microbiol ; 114(1): 36-43, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22978364

ABSTRACT

AIM: This study was performed to investigate the possibility to photodynamically inactivate Gram-negative bacteria without intracellular uptake of the photosensitizer. The efficiency of the photodynamic growth inhibition of Escherichia coli (SURE2) was proved in a comparative study of a neutral and a cationic photosensitizer. METHODS AND RESULTS: We used confocal laser scanning microscopy (CLSM) to investigate the uptake of the photosensitizer by the bacteria to show that both chlorin e(6) and TMPyP are not accumulated in the cells. Fluorescence lifetime imaging (FLIM) and phototoxicity experiments were used to investigate the photodynamic inactivation of the Gram-negative bacteria. The phototoxicity experiments were carried out using a white light LED-setup to irradiate the bacterial suspensions. The viability of the bacteria was obtained by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-assay. For the cationic TMPyP, photodynamic inactivation without intracellular uptake was observed, whereas for chlorin e(6) such behaviour was not found. CONCLUSIONS: It was proven that in general, it is possible to photodynamically inactivate Gram-negative bacteria without photosensitizer accumulation in the bacterial cells. This fact is especially interesting, considering that the development of resistances may be prevented, leaving the active components outside the bacterium. SIGNIFICANCE AND IMPACT OF THE STUDY: In a world with bacteria that gain the ability to withstand the effects of antibiotics and are able to transmit on these resistances to the next generation, it becomes necessary to develop new approaches to inhibit the growth of multi-resistant bacteria. The photodynamic inactivation of bacteria is based on a three-component system by which the growth of the bacterial cells is inhibited. The well-directed oxidative damage is initiated by visible light of a certain wavelength, which excites a nontoxic photoactive molecule, called photosensitizer. Its reaction with oxygen causes the generation of cytotoxic species like singlet oxygen, which is highly reactive and causes the inactivation of the growth of bacteria.


Subject(s)
Escherichia coli/drug effects , Photosensitizing Agents/pharmacology , Porphyrins/pharmacology , Microbial Viability , Microscopy, Confocal , Photosensitizing Agents/metabolism , Porphyrins/metabolism
7.
Pharmacopsychiatry ; 43(2): 58-65, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20336598

ABSTRACT

INTRODUCTION: The aim of this prospective naturalistic study was to examine for the first time the relationship between dosage, serum concentration and clinical outcome in children and adolescents with impulsive-aggressive symptoms during risperidone therapy. METHODS: Steady state trough serum concentrations of risperidone and 9-hydroxyrisperidone (the active moiety) were measured in 103 subjects. The therapeutic effect was assessed by the clinical global impression improvement subscale and side effects by the Udvalg for Kliniske Undersogelser-side effect rating scale. RESULTS: We found a linear relationship between the risperidone dose and the serum concentration of the active moiety (Spearman rho=0.53) and no correlation between the serum concentration and either the therapeutic effect or side effects. There was no effect of gender and co-medication. DISCUSSION: This study has the typical limitations of naturalistic studies, therefore our results should be interpreted with caution. Based on the serum concentrations at the therapeutically effective dose range (0.25-1.5 mg/day) we obtained first information on a possibly appropriate therapeutic serum range for the risperidone treatment of children and adolescents with impulsive-aggressive symptoms. Further studies with greater sample sizes are needed to validate our results and to examine the influence of genetic polymorphisms on the serum concentration of risperidone.


Subject(s)
Aggression/drug effects , Antipsychotic Agents/therapeutic use , Child Behavior Disorders/drug therapy , Disruptive, Impulse Control, and Conduct Disorders/drug therapy , Risperidone/therapeutic use , Adolescent , Age Factors , Aggression/physiology , Antipsychotic Agents/adverse effects , Antipsychotic Agents/blood , Child , Child Behavior Disorders/blood , Disruptive, Impulse Control, and Conduct Disorders/blood , Dose-Response Relationship, Drug , Female , Humans , Isoxazoles/blood , Linear Models , Male , Paliperidone Palmitate , Prospective Studies , Psychiatric Status Rating Scales , Pyrimidines/blood , Risperidone/adverse effects , Risperidone/blood , Sex Factors , Treatment Outcome
8.
Biotechnol Bioeng ; 79(6): 595-601, 2002 Sep 20.
Article in English | MEDLINE | ID: mdl-12209806

ABSTRACT

Using transient expression, high amounts (>20 mg/mL) of secreted anti-human Rhesus-D IgG1 were produced in a suspension-adapted HEK293 EBNA cell line (Meissner et al., Biotechnol Bioeng 75: 197-203, 2001). Time of harvest was 3 days after transfection. For the estimation of transfection efficiencies, we routinely co-transfected EGFP reporter DNA. At higher reporter plasmid concentrations, >2% of total transfecting plasmid DNA, a substantial reduction of recombinant antibody synthesis, was observed. This phenomenon was investigated in detail by co-expressing various green fluorescent protein (GFP) reporter constructs, which were targeted at different subcellular locations. Enhanced and humanized GFPs targeted to either the endoplasmic reticulum, the cytosol, or the nucleus reduced recombinant antibody production by 30 to 40% when present at higher concentrations in the transfection solution. The most severe effects were observed when the co-transfected EGFP was targeted to the endoplasmic reticulum, leading to a reduction of up to 80% in the presence of only 5% of reporter DNA. Interestingly, one nuclear-targeted GFP variant that was not codon optimized for expression in human cell lines could be added, to up to almost half of the total amount of transfecting DNA, without adverse effect on antibody production. Although the minimum amount of this reporter DNA needed for fluorescence reading was 10 times higher than for the other variants, it provided a much broader quantity range within which the transfection process could be studied without being negatively affected.


Subject(s)
Genes, Reporter , Immunoglobulin G/biosynthesis , Immunoglobulin G/genetics , Luminescent Proteins/genetics , Plasmids , Transfection/methods , Animals , Cell Line , Gene Expression Regulation , Green Fluorescent Proteins , Humans , Kidney/cytology , Kidney/embryology , Macaca mulatta/genetics , Quality Control , Recombinant Proteins/biosynthesis , Recombinant Proteins/genetics
9.
Cytotechnology ; 33(1-3): 139-45, 2000 Jul.
Article in English | MEDLINE | ID: mdl-19002821

ABSTRACT

For the controlled production of recombinant proteinsin mammalian cells by transient transfection, it maybe desirable not only to manipulate, but also todiagnose the expression success early. Here, weapplied laser scanning confocal microscopy to monitortransfection induced intracellular Ca(2+)responses. We compared Chinese hamster ovary (CHO K1)versus human embryo kidney (HEK) 293 cell lines, whichdiffer largely in their transfectability. An improvedcalcium phosphate transfection method was used for itssimplicity and its demonstrated upscale potential.Cytosolic Ca(2+) signaling appeared to inverselyreflect the cellular transfection fate. Virtually allCHO cells exhibited asynchronous, cytosolicCa(2+) oscillations, which peaked 4 h afteraddition of the transfecting solution. Yet, most ofthe HEK cells displayed a slow and continuousCa(2+) increase over the time of transfection. CHOcells, when exposed to a transfection-enhancingglycerol shock, strongly downregulated their Ca(2+)response, including its oscillations. When treatedwith thapsigargin, a Ca(2+) store depleting drug,the number of successfully transfected CHO cells was significantly reduced. Our result points tointracellular store release as a critical componentfor the transfection fate of CHO cells, and its early detection before product visualization.

10.
J Bacteriol ; 181(4): 1189-95, 1999 Feb.
Article in English | MEDLINE | ID: mdl-9973345

ABSTRACT

Biodegradation of 2,4,6-trinitrophenol (picric acid) by Rhodococcus erythropolis HLPM-1 proceeds via initial hydrogenation of the aromatic ring system. Here we present evidence for the formation of a hydride-Meisenheimer complex (anionic sigma-complex) of picric acid and its protonated form under physiological conditions. These complexes are key intermediates of denitration and productive microbial degradation of picric acid. For comparative spectroscopic identification of the hydride complex, it was necessary to synthesize this complex for the first time. Spectroscopic data revealed the initial addition of a hydride ion at position 3 of picric acid. This hydride complex readily picks up a proton at position 2, thus forming a reactive species for the elimination of nitrite. Cell extracts of R. erythropolis HLPM-1 transform the chemically synthesized hydride complex into 2,4-dinitrophenol. Picric acid is used as the sole carbon, nitrogen, and energy source by R. erythropolis HLPM-1.


Subject(s)
Picrates/metabolism , Rhodococcus/metabolism , Anions , Biodegradation, Environmental , Chromatography, High Pressure Liquid , Hydrogen , Models, Chemical , Nuclear Magnetic Resonance, Biomolecular , Picrates/chemistry , Rhodococcus/growth & development
11.
Herz ; 21(6): 389-96, 1996 Dec.
Article in German | MEDLINE | ID: mdl-9081908

ABSTRACT

Short-term and long-term results are the classical parameters for quality assurance in coronary artery bypass graft surgery (CABGS). In contrast, waiting times and the inherent risks of waiting lists are usually neglected. Although the problem of "death on the waiting list" is generally known, related publications are scarce. Therefore, in January 1994, we started a prospective study to document the waiting times and the occurrence of severe complications in our patients waiting for CABGS. Between January 1, 1994 and July 31, 1996, we catheterized 1125 patients with indication for CABGS. 968 patients had social health insurance (SOCL); 157 patients were privately insured (PRIV). The urgency of CABGS was classified as "emergent", "ery urgent" and "less urgent" according to the clinical experience of the responsible cardiologists. All emergency cases could be operated the same day. 69% of the very urgent SOCL patients had to travel beyond the Munich area to be operated, while 84% of the respective PRIV patients were operated in Munich. SOCL patients were therefore separated from their families 4.3 times more frequently then PRIV. Not so urgent SOCL cases were separated from their families 1.8 times more often than PRIV. The mean waiting time for SOCL was 39.5 +/- 39.1 days in 1994, 34.9 +/- 31.5 days in 1995 and 22.7 +/- 16 days in 1996. The corresponding values of PRIV are 19.1 +/- 16.2, 19.8 +/- 14.1 and 17.2 +/- 12.6 days. The risk of dying while waiting for CABGS was 1.3% per month (15/1125). The reduction of waiting times by the factor of two between 1994 and 1996 did not, however, influence the death on the waiting list, because all deaths occurred within 4 weeks after diagnostic catheterization. Our results show that triage practices for patients requiring CABGS are not reliable. To minimize the risk of the "death on the waiting list", CABGS must be offered within a week after diagnostic coronary angiography, even for "elective" cases.


Subject(s)
Coronary Artery Bypass/mortality , Coronary Disease/mortality , National Health Programs/statistics & numerical data , Quality Assurance, Health Care/statistics & numerical data , Waiting Lists , Adult , Aged , Aged, 80 and over , Cardiac Catheterization/statistics & numerical data , Elective Surgical Procedures/statistics & numerical data , Female , Germany/epidemiology , Health Services Accessibility/legislation & jurisprudence , Humans , Male , Middle Aged , Survival Analysis , Triage
12.
Electrophoresis ; 17(4): 659-66, 1996 Apr.
Article in English | MEDLINE | ID: mdl-8738323

ABSTRACT

Two-dimensional (2-D) DNA fingerprinting is a promising technique for multilocus analysis of eukaryotic genomes. It has been successfully applied to the detection of DNA variation in tumors, to linkage analyses and to genomic comparisons of inbred mouse strains. However, there are still problems with inter-gel comparisons of 2-D DNA typing patterns as documented by the inter-gel reproducibility rates reported in the literature, which range from 84 to 98%. The basis for standardization in almost all of these studies has been a set of lambda fragments (digested separately with the restriction enzymes HaeIII, RsaI, Bg/I) that produces a spot pattern scattered across the gel. These spots are used as markers for gel comparisons. Since we noticed considerable variations in the marker spot patterns, we evaluated the properties of the lambda marker using both computer simulation and an empirical analysis of forty independent consecutive gels from our laboratory. We explain the instabilities of the spot pattern on the basis of the melting properties of the individual lambda fragments. A subset of spots is presented that has been stable in all our experiments. Only this set of spots should be used for gel standardization purposes until a new, completely reproducible marker becomes available. Finally, suggestions for an improved marker system are made.


Subject(s)
Bacteriophage lambda/genetics , Computer Simulation , DNA Fingerprinting/methods , DNA, Viral/analysis , Electrophoresis, Gel, Two-Dimensional/methods , Models, Molecular , Base Sequence , Methylation , Molecular Sequence Data , Problem Solving , Reproducibility of Results
13.
Anal Bioanal Chem ; 353(3-4): 399-402, 1995 Oct.
Article in English | MEDLINE | ID: mdl-15048507

ABSTRACT

The oxidation of InSn48 has been investigated at partial pressures between 10(-8) Pa and 10(+4) Pa over a temperature range from 22 ( degrees )C to 250 ( degrees )C with different analytical methods. The oxide film contains a mixture of several oxides, although indium oxide forms preferentially. Below the melting point a logarithmic growth, and above this, a parabolic growth of the oxide film has been observed. The oxide film formed in air at 250 ( degrees )C does not become thicker than 50 nm in the first 5 min of oxidation.

14.
Cereb Cortex ; 4(6): 576-89, 1994.
Article in English | MEDLINE | ID: mdl-7703685

ABSTRACT

It has traditionally been held that the adult brain is incapable of significant self-repair, due in part to its inability to generate new neurons. Nevertheless, rodents and birds have been found to harbor neural precursor cells in adulthood. We asked whether the adult human brain might retain such precursors, by culturing samples of temporal lobe under conditions permissive for neuronal differentiation, while exposed to 3H-thymidine. Adult human temporal lobe cultures, derived from cortex, subcortex, and periventricular subependymal zone (SZ), were incubated for 7-28 d, stained for neuronal and glial antigens, and autoradiographed. Neuron-like cells were found in explant outgrowths and monolayer dissociates of SZ and periventricular white matter, but not cortex; they expressed neuronal antigens including MAP-2, MAP-5, NF, and N-CAM, and were GFAP-. Neurons responded to K+ depolarization with rapid and reversible increases in intracellular Ca2+, with much greater increments than those noted in glia. Although most neurons were not 3H-thymidine labeled, a small number of MAP-2+ and MAP-5+/GFAP- cells did incorporate 3H-thymidine, suggesting neuronal production from precursor mitosis. Rare 3H-thymidine+ neurons were also found in cultures of subventricular white matter; in these, GFAP+ astrocytic mitogenesis was common, while O4+ oligodendrocytes, although the predominant cell type, were largely postmitotic. Thus, the adult human forebrain harbors precursor cells that retain the potential for neuronal production and differentiation in vitro.


Subject(s)
Neurons/physiology , Prosencephalon/growth & development , Adolescent , Adult , Autoradiography , Calcium/metabolism , Cell Differentiation/physiology , Cells, Cultured , Culture Media , Female , Humans , Image Processing, Computer-Assisted , Immunohistochemistry , Male , Middle Aged , Neuroglia/physiology , Phenotype , Prosencephalon/cytology , Thymidine/metabolism
15.
J Neurochem ; 62(5): 1983-8, 1994 May.
Article in English | MEDLINE | ID: mdl-8158144

ABSTRACT

Glutamine transaminase K and omega-amidase activities are present in the chick brain and in the brains of adult mice, rats, and humans. However, the activity of glutamine transaminase K in adult mouse brain is relatively low. In the chick embryo, cerebral glutamine transaminase K activity is low between embryonic days 5 and 17, but by day 23 (day of hatching) activity rises dramatically (> 15-fold). Cerebral omega-amidase activity is relatively high at embryonic day 5 but lower between days 5 and 17; at embryonic day 23 the activity rises to a maximum. Both glutamine transaminase K and omega-amidase are present in cultured chick, rat, and mouse astrocytes and neurons. For each species, the activity of glutamine transaminase K is higher in the astrocytes than in the neurons. The activity of omega-amidase is about the same in the cultured chick astrocytes and neurons but significantly higher in rat astrocytes than in rat neurons. The data suggest that the rise in brain glutamine transaminase K activity in the chick embryo at hatching correlates with maturation of astrocytes. Glutamine transaminase K may be involved in glutamine cycling in astrocytes. Glutamine transaminase K appears to be a major cysteine S-conjugate beta-lyase of the brain and may play a role in the neurotoxicity associated with exposure to dichloroacetylene and perhaps to other toxins.


Subject(s)
Amidohydrolases/metabolism , Astrocytes/enzymology , Brain/enzymology , Lyases/metabolism , Neurons/enzymology , Prosencephalon/embryology , Prosencephalon/enzymology , Transaminases/metabolism , Animals , Cells, Cultured , Chick Embryo , Embryonic and Fetal Development , Enzyme Induction , Humans , Kinetics , Lyases/biosynthesis , Mice , Rats , Transaminases/biosynthesis
16.
J Neurochem ; 62(1): 45-53, 1994 Jan.
Article in English | MEDLINE | ID: mdl-7903354

ABSTRACT

GSH, GSSG, vitamin E, and ascorbate were measured in 14-day cultures of chick astrocytes and neurons and compared with levels in the forebrains of chick embryos of comparable age. Activities of enzymes involved in GSH metabolism were also measured. These included gamma-glutamylcysteine synthetase, GSH synthetase, gamma-glutamyl cyclotransferase, gamma-glutamyltranspeptidase, glutathione transferase (GST), GSH peroxidase, and GSSG reductase. The concentration of lipid-soluble vitamin E in the cultured neurons was found to be comparable with that in the forebrain. On the other hand, the concentration of vitamin E in the astrocytes was significantly greater in the cultured astrocytes than in the neurons, suggesting that the astrocytes are able to accumulate exogenous vitamin E more extensively than neurons. The concentrations of major fatty acids were higher in the cell membranes of cultured neurons than those in the astrocytes. Ascorbate was not detected in cultured cells although the chick forebrains contained appreciable levels of this antioxidant. GSH, total glutathione (i.e., GSH and GSSG), and GST activity were much higher in cultured astrocytes than in neurons. gamma-Glutamylcysteine synthetase activity was higher in the cultured astrocytes than in the cultured neurons. GSH reductase and GSH peroxidase activities were roughly comparable in cultured astrocytes and neurons. The high levels of GSH and GST in cultured astrocytes appears to reflect the situation in vivo. The data suggest that astrocytes are resistant to reactive oxygen species (and potentially toxic xenobiotics) and may play a protective role in the brain.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Antioxidants/metabolism , Ascorbic Acid/metabolism , Astrocytes/metabolism , Brain/metabolism , Glutathione/metabolism , Neurons/metabolism , Prosencephalon/metabolism , Vitamin E/metabolism , Animals , Cell Communication , Cells, Cultured , Chick Embryo , Glutamate-Cysteine Ligase/metabolism , Glutathione/analogs & derivatives , Glutathione Disulfide , Glutathione Peroxidase/metabolism , Glutathione Synthase/metabolism , Glutathione Transferase/metabolism , Kinetics , Prosencephalon/embryology , Protein Disulfide Reductase (Glutathione)/metabolism , gamma-Glutamylcyclotransferase/metabolism , gamma-Glutamyltransferase/metabolism
17.
Arch Microbiol ; 159(4): 345-53, 1993.
Article in English | MEDLINE | ID: mdl-8484707

ABSTRACT

A sulfate-reducing bacterium using trinitrotoluene (TNT) as the sole nitrogen source was isolated with pyruvate and sulfate as the energy sources. The organism was able to reduce TNT to triaminotoluene (TAT) in growing cultures and cell suspensions and to further transform TAT to still unknown products. Pyruvate, H2, or carbon monoxide served as the electron donors for the reduction of TNT. The limiting step in TNT conversion to TAT was the reduction of 2,4-diamino-6-nitrotoluene (2,4-DANT) to triaminotoluene. The reduction proceeded via 2,4-diamino-6-hydroxylaminotoluene (DAHAT) as an intermediate. The intermediary formation of DAHAT was only observed in the presence of carbon monoxide or hydroxylamine, respectively. The reduction of DAHAT to triaminotoluene was inhibited by both CO and NH2OH. The inhibitors as well as DANT and DAHAT significantly inhibited sulfide formation from sulfite. The data were taken as evidence for the involvement of dissimilatory sulfite reductase in the reduction of DANT and/or DAHAT to triaminotoluene. Hydrogenase purified from Clostridium pasteurianum and carbon monoxide dehydrogenase partially purified from Clostridium thermoaceticum also catalyzed the reduction of DANT in the presence of methyl viologen or ferredoxin, however, as the main reduction product DAHAT rather than triaminotoluene was formed. The findings could explain the function of CO as an electron donor for the DANT reduction (to DAHAT) and the concomitant inhibitory effect of CO on triaminotoluene formation (from DAHAT) by the inhibition of sulfite reductase.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Sulfur-Reducing Bacteria/metabolism , Toluidines/metabolism , Trinitrotoluene/metabolism , Anaerobiosis , Biodegradation, Environmental , Sulfur-Reducing Bacteria/isolation & purification
18.
Exp Brain Res ; 79(1): 207-11, 1990.
Article in English | MEDLINE | ID: mdl-2311698

ABSTRACT

The responses of single and multi units in the medial geniculate body of the squirrel monkey (Saimiri sciureus) to modulation frequency, modulation depth and changes in absolute intensity of sinusoidally amplitude modulated (AM) sounds were studied. Both spike-frequency and spike rate modulation were used as a measure for neuronal response. Spike rate modulation was derived from FFT (Fast-Fourier-Transformation) analysis of the PSTHs. In all cases (N = 133) spike rate modulation was shown to be dependent on the stimulus modulation frequency: Most neurons responded best to one modulation frequency, i.e., they showed a modulation transfer function with bandpass characteristic; only a few displayed a low pass or multiple peaked transfer characteristic. The majority of the neurons responded best in a range from 4 to 64 Hz, with a peak at 32 Hz and a median at 16 Hz. Such modulation frequencies are common in parts of the species vocal repertoire.


Subject(s)
Auditory Pathways/physiology , Cebidae/physiology , Geniculate Bodies/physiology , Saimiri/physiology , Sound , Acoustic Stimulation , Action Potentials , Animals
19.
Brain Res ; 493(1): 198-203, 1989 Jul 24.
Article in English | MEDLINE | ID: mdl-2776007

ABSTRACT

Antidromically identified neurons projecting to the putamen (CPNs) and pyramidal tract neurons (PTNs) were recorded from motor and premotor cortex of a monkey which performed a load-bearing task with the wrist. CPNs appeared as a uniform population with very slowly conducting axons and low spontaneous activity. In contrast to PTNs, they exhibited weak, mostly insignificant correlation with graded steady-state forces, responded to torque perturbations with remarkably long latency, and seemed to discharge much later with active movement. Collateral branching of PTNs to the putamen was found to be infrequent (1%). We suggest that the putamen receives a cortical message that is strikingly different from that sent down the pyramidal tract.


Subject(s)
Corpus Striatum/physiology , Motor Cortex/physiology , Putamen/physiology , Pyramidal Tracts/physiology , Animals , Evoked Potentials , Macaca mulatta , Male , Neurons/physiology
20.
Rev. bras. ortop ; 18(4): 131-5, 1983.
Article in Portuguese | LILACS | ID: lil-17444

ABSTRACT

Sao analisados 79 casos de osteomielite aguda hematogenica e o resultado do tratamento na fase inicial. Quatro foram tratados de forma conservadora, 17 com drenagem local e 58 submetidos a instilacao-aspiracao pelo metodo de Compere. Os resultados a curto prazo foram classificados na categoria de "bom" em 56,96% dos pacientes. Os casos de melhor evolucao foram os de criancas entre 0 a 3 anos de idade com bom estado geral e nutritivo, que receberam como medicacao antibiotica a associacao de penicilina cristalina e oxacilina, complementada por dicloxacilina.Os autores alerta, para a necessidade de sistematizacao de atendimento e tratamento dos pacientes e descrevem o protocolo usado em seu servico


Subject(s)
Infant , Child, Preschool , Child , Adolescent , Humans , Male , Female , Osteomyelitis , Anti-Bacterial Agents , Surgical Procedures, Operative
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