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1.
Insect Mol Biol ; 27(6): 815-823, 2018 12.
Article in English | MEDLINE | ID: mdl-30040150

ABSTRACT

Age-dependent division of labour in honeybees was shown to be connected to sensory response thresholds. Foragers show a higher gustatory responsiveness than nurse bees. It is generally assumed that nutrition-related signalling pathways underlie this behavioural plasticity. Here, one important candidate gene is the foraging gene, which encodes a cyclic guanosine monophosphate-dependent protein kinase (PKG). Several roles of members of this enzyme family were analysed in vertebrates. They own functions in important processes such as growth, secretion and neuronal adaptation. Honeybee foraging messenger RNA expression is upregulated in the brain of foragers. In vivo activation of PKG can modulate gustatory responsiveness. We present for the first time PKG protein level and activity data in the context of social behaviour and feeding. Protein level was significantly higher in brains of foragers than in those of nurse bees, substantiating the role of PKG in behavioural plasticity. However, enzyme activity did not differ between behavioural roles. The mediation of feeding status appears independent of PKG signalling. Neither PKG content nor enzyme activity differed between starved and satiated individuals. We suggest that even though nutrition-related pathways are surely involved in controlling behavioural plasticity, which involves changes in PKG signalling, mediation of satiety itself is independent of PKG.


Subject(s)
Bees/enzymology , Behavior, Animal , Cyclic GMP-Dependent Protein Kinases/metabolism , Animals , Insect Proteins/metabolism , Satiation , Sucrose
2.
Acta Anaesthesiol Scand ; 54(6): 770-6, 2010 Jul.
Article in English | MEDLINE | ID: mdl-20397982

ABSTRACT

BACKGROUND: The purpose of this study was to determine systematically the highest minimal stimulation current threshold for regional anaesthesia in pigs. METHODS: In an established pig model for regional anaesthesia, needle placements applying electric nerve stimulation were performed. The primary outcome was the frequency of close needle to nerve placements as assessed by resin injects and subsequent anatomical evaluation. Following a statistical model (continual reassessment method), the applied output currents were selected to limit the necessary number of punctures, while providing guidance towards the highest output current range. RESULTS: Altogether 186 punctures were performed in 11 pigs. Within the range of 0.3-1.4 mA, no distant needle to nerve placement was found. In the range of 1.5-4.1 mA, 43 distant needle to nerve placements occurred. The range of 1.2-1.4 mA was the highest interval that resulted in a close needle to nerve placement rate of > or =95%. CONCLUSIONS: In the range of 0.3-1.4 mA, all resin deposition was found to be adjacent to nerve epineurium. The application of minimal current intensities up to 1.4 mA does not obviously lead to a reduction of epineural injectate contacts in pigs. These findings suggest that stimulation current thresholds up to 1.4 mA result in equivalent needle tip localisation in pigs.


Subject(s)
Electric Stimulation/methods , Nerve Block/methods , Animals , Axilla , Brachial Plexus/physiology , Brachial Plexus/ultrastructure , Catheterization , Electrodes, Implanted , Electromagnetic Phenomena , Extremities/innervation , Female , Femoral Nerve/physiology , Femoral Nerve/ultrastructure , Groin , Muscle Contraction , Peripheral Nerves/ultrastructure , Single-Blind Method , Sus scrofa , Swine
3.
HNO ; 57(11): 1121-5, 2009 Nov.
Article in German | MEDLINE | ID: mdl-19039566

ABSTRACT

Lipomata of the head and neck mostly present as cosmetically disturbing, superficial lesions lying within the subcutaneous tissue such that they can be easily removed by minor surgical interventions. In cases of deeply extended, lipomatous tumors, as reported here regarding two exemplary cases, physicians should always take into account that they might have to deal with infiltrative, intramuscular lipomata or even malignant neoplasms, especially if concomitant functional disorders are observed. Even though such tumors are rare in the head and the neck, preoperative planning must anticipate these possible pathological entities. At any stage, modification of the surgical procedure should be possible according to the intraoperative findings, as these tumors are prone to recurrence after incomplete resection. The actual diagnosis with infiltration of the surrounding tissue cannot be sufficiently made either by adequate imaging techniques or by preoperative fine-needle cytology but only by histological workup of the resected, tumorous tissue.


Subject(s)
Head and Neck Neoplasms/diagnosis , Lipoma/diagnosis , Magnetic Resonance Imaging , Muscle Neoplasms/diagnosis , Ultrasonography , Aged , Diagnosis, Differential , Female , Head and Neck Neoplasms/pathology , Head and Neck Neoplasms/surgery , Humans , Lipoma/pathology , Lipoma/surgery , Male , Middle Aged , Muscle Neoplasms/pathology , Muscle Neoplasms/surgery , Neck Muscles/pathology , Neck Muscles/surgery , Neoplasm Invasiveness , Prognosis , Reoperation
4.
Neuron ; 21(2): 295-304, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9728911

ABSTRACT

Cell lineage analyses suggest that cortical neuroblasts are capable of undertaking both radial and tangential modes of cell movement. However, it is unclear whether distinct progenitors are committed to generating neuroblasts that disperse exclusively in either radial or tangential directions. Using highly unbalanced mouse stem cell chimeras, we have identified certain progenitors that are committed to one mode of cell dispersion only. Radially dispersed neurons expressed glutamate, the neurochemical signature of excitatory pyramidal cells. In contrast, tangential progenitors gave rise to widely scattered neurons that are predominantly GABAergic. These results suggest lineage-based mechanisms for early specification of certain progenitors to distinct dispersion pathways and neuronal phenotypes.


Subject(s)
Cell Movement/physiology , Neocortex/embryology , Neurons/cytology , Stem Cells/physiology , Animals , Cell Lineage , Chimera , Embryonic and Fetal Development/physiology , Glutamic Acid/physiology , Linear Models , Mice , Mice, Transgenic , Neocortex/cytology , Phenotype , gamma-Aminobutyric Acid/physiology
5.
J Clin Invest ; 101(7): 1421-30, 1998 Apr 01.
Article in English | MEDLINE | ID: mdl-9525985

ABSTRACT

The gastrointestinal hormone, glucagon-like peptide-1(7-36)amide (GLP-1) is released after a meal. The potency of synthetic GLP-1 in stimulating insulin secretion and in inhibiting glucagon secretion indicates the putative physiological function of GLP-1. In vitro, the nonmammalian peptide, exendin(9-39)amide [ex(9-39)NH2], is a specific and competitive antagonist of GLP-1. This in vivo study examined the efficacy of ex(9-39)NH2 as an antagonist of exogenous GLP-1 and the physiological role of endogenous GLP-1. Six healthy volunteers underwent 10 experiments in random order. In each experiment, a 30-min period of euglycemia was followed by an intravenous infusion of glucose for 150 min that established a stable hyperglycemia of 8 mmol/liter. There was a concomitant intravenous infusion of one of the following: (1) saline, (2) GLP-1 (for 60 min at 0.3 pmol . kg-1 . min-1 that established physiological postprandial plasma levels, and for another 60 min at 0.9 pmol . kg-1 . min-1 to induce supraphysiological plasma levels), (3-5) ex(9-39)NH2 at 30, 60, or 300 pmol . kg-1 . min-1 + GLP-1, (6-8) ex(9-39)NH2 at 30, 60, or 300 pmol . kg-1 . min-1 + saline, (9 and 10) GIP (glucose-dependent insulinotropic peptide; for 60 min at 0.8 pmol . kg-1 . min-1, with saline or ex(9-39)NH2 at 300 pmol . kg-1 . min-1). Each volunteer received each of these concomitant infusions on separate days. ex(9-39)NH2 dose-dependently reduced the insulinotropic action of GLP-1 with the inhibitory effect declining with increasing doses of GLP-1. ex(9-39)NH2 at 300 pmol . kg-1 . min-1 blocked the insulinotropic effect of physiological doses of GLP-1 and completely antagonized the glucagonostatic effect at both doses of GLP-1. Given alone, this load of ex(9-39)NH2 increased plasma glucagon levels during euglycemia and hyperglycemia. It had no effect on plasma levels of insulin during euglycemia but decreased plasma insulin during hyperglycemia. ex(9-39)NH2 did not alter GIP-stimulated insulin secretion. These data indicate that in humans, ex(9-39)NH2 is a potent GLP-1 antagonist without any agonistic properties. The pancreatic A cell is under a tonic inhibitory control of GLP-1. At hyperglycemia, the B cell is under a tonic stimulatory control of GLP-1.


Subject(s)
Glucagon/antagonists & inhibitors , Peptide Fragments/antagonists & inhibitors , Peptide Fragments/pharmacology , Protein Precursors/antagonists & inhibitors , Receptors, Glucagon/antagonists & inhibitors , Adult , C-Peptide/blood , Glucagon/blood , Glucagon-Like Peptide 1 , Glucagon-Like Peptide-1 Receptor , Glucose/metabolism , Humans , Insulin/blood , Male , Peptide Fragments/blood , Protein Precursors/blood , Time Factors
6.
Eur J Trauma Emerg Surg ; 43(2): 155-161, 2017 Apr.
Article in English | MEDLINE | ID: mdl-27272916

ABSTRACT

PURPOSE: Continuous lateral rotational therapy (CLRT) has been described as a promising approach for prophylaxis and treatment of respiratory complications in critically ill patients over two decades ago. However, meta-analyses failed to demonstrate any significant benefit on outcome by CLRT, possibly due to the heterogeneity and low overall quality of available studies. METHODS: Observational trial over a 3-year period on outcome in trauma patients (Injury Severity Score, ISS ≥16) with severe thoracic injury (Abbreviated Injury Scale, AISThorax ≥3) initially treated with CLRT as standard of care. Epidemiological data, injury severity, and pattern and physiological parameters were recorded. Outcome indicators were time on mechanical ventilation, length of stay, rates of pneumonia, sepsis and acute respiratory distress syndrome, hospital mortality, and rates of re-intubation. Additionally, data are compared with the results from the TraumaRegister® of the German Trauma Society. RESULTS: Over the 3-year period 76 patients with ISS ≥16/AISThorax ≥3 received CLRT, equaling 24 % of all patients with ISS ≥16 between 18 and 80 years. Mean ISS was 35.3 (standard deviations, SD 12.2) [71.1 % male, 97.4 % blunt trauma, mean age 43.9 years (SD 18.7)]. Mean time on CLRT was 3.3 days (SD 2.2), time on mechanical ventilation 7.8 days (SD 7.1), and 9.2 % had to be re-intubated due to respiratory complications. CLRT-related complications occurred in 8.9 %. Overall 25 % of the patients developed pneumonia (VAP = 13.2 %). Despite a significantly higher ISS we observed shorter times on mechanical ventilation and intensive care unit in our collective in comparison to data published from the nationwide TraumaRegister®. CONCLUSIONS: CLRT remains a therapeutic option to reduce pulmonary complications after severe chest trauma in our center. However, a RCT is needed to study the effects of other treatment options such as early extubation and non-invasive ventilation or prone/supine positioning.


Subject(s)
Critical Care/methods , Intensive Care Units , Motion Therapy, Continuous Passive/methods , Multiple Trauma/therapy , Thoracic Injuries/therapy , Wounds, Nonpenetrating/therapy , Adolescent , Adult , Aged , Aged, 80 and over , Europe/epidemiology , Female , Hospital Mortality , Humans , Injury Severity Score , Kinetics , Length of Stay , Male , Middle Aged , Multiple Trauma/mortality , Multiple Trauma/physiopathology , Patient Positioning , Pneumonia/mortality , Prospective Studies , Respiratory Distress Syndrome/mortality , Sepsis/mortality , Thoracic Injuries/mortality , Thoracic Injuries/physiopathology , Trauma Centers , Treatment Outcome , Wounds, Nonpenetrating/mortality , Wounds, Nonpenetrating/physiopathology , Young Adult
7.
Appl Radiat Isot ; 125: 163-168, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28453976

ABSTRACT

Pulse shape discrimination is an important handle to improve sensitivity in low background experiments. A dedicated setup was built to investigate the response of high-purity germanium detectors to single Compton scattered events. Using properly collimated γ-ray sources, it is possible to select events with known interaction location. The aim is to correlate the position dependent signal shape with geometrical and electrical properties of the detector. We report on design and performance of the setup with a first look on data.

8.
Int J Dev Biol ; 43(1): 69-73, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10213084

ABSTRACT

The activity of two X-linked genes, Pgk1 and Hprt, that are localized on X-chromosomes of different parental origins in the XX mouse embryo was analyzed by the quantification of allele-specific transcripts. For the Pgk1 gene, the maternal allele-specific transcripts were consistently more abundant than the paternal transcripts in the blastocyst and the late gastrula. For the Hprt gene, the Hprt(b) allele was preferentially expressed in the blastocysts when it is present on the maternal X-chromosome. However, this skewed expression of the maternal allele was not observed in the reciprocal situation when the Hprt(a) allele was on the maternal X-chromosome. Like the Pgk1 locus, significantly more maternal Hprt transcripts were found in the gastrula-stage embryos irrespective of their genotypes. One possible interpretation of these results is that, in the XX mouse embryos, the genetic loci on maternal X-chromosome may be transcriptionally more active than their paternal counterparts during peri-implantation development.


Subject(s)
Genomic Imprinting , Hypoxanthine Phosphoribosyltransferase/genetics , Phosphoglycerate Kinase/genetics , X Chromosome , Alleles , Animals , Blastocyst/metabolism , Dosage Compensation, Genetic , Female , Gastrula/metabolism , Gene Expression Regulation, Developmental , Genetic Linkage , Male , Mice , Reverse Transcriptase Polymerase Chain Reaction , Time Factors
9.
Dev Genes Evol ; 206(6): 377-388, 1997 01.
Article in English | MEDLINE | ID: mdl-27747399

ABSTRACT

The developmental potential of parthenogenetic embryonic stem (P-ES) cells was studied in teratomas and mouse chimaeras. Teratomas derived from P-ES cells contained a mixture of tissue types with variable proportions of specific tissues. Three of the eight P-ES cell lines analysed showed high proportions of striated muscle in teratomas, similar to teratomas from normal embryos or ES cell lines derived from fertilised embryos (F-ES cells). Our study also revealed that one P-ES cell line showed little lineage restriction in injection chimaeras. Descendants of the P-ES cells contributed to most tissues of chimaeric fetuses in patterns similar to F-ES cells. Normal colonisation of muscle, liver and pancreas was found in adult chimaeras. P-ES cells also showed similar haematopoietic differentiation and maturation as F-ES cells. However, extensive P-ES cell contribution was associated with a reduction in body size. These findings suggest that, while P-ES cells display more extensive developmental potential than the cells of parthenogenetic embryos from which they were derived, they only retained properties related to the presence of the maternal genome. To elucidate the molecular basis for the lack of lineage restriction during in vivo differentiation, the expression of four imprinted genes, H19, Igf2r, Igf2 and Snrpn was compared among five P-ES and two F-ES cell lines. Expression levels of these genes varied among the different ES cell lines, both in undifferentiated ES cells and in embryoid bodies.


Subject(s)
Embryonic Stem Cells/cytology , Animals , Cell Culture Techniques , Cell Differentiation , Chimera , Embryoid Bodies/cytology , Genomic Imprinting , Mice , Parthenogenesis , Teratoma/metabolism
10.
J Med Chem ; 26(8): 1174-87, 1983 Aug.
Article in English | MEDLINE | ID: mdl-6876086

ABSTRACT

A series of 4,N-disubstituted 5-sulfamoylorthanilic acids was synthesized by nucleophilic substitution reactions starting either from 2,4-dihalogeno-5-sulfamoylbenzenesulfonic acids or, in most cases, from phenyl 2,4-dihalogeno-5-sulfamoylbenzenesulfonates. The latter method is based on the relative stability of the phenoxysulfonyl group to nucleophiles, e.g., amines, phenols, and thiols, and the possibility of smooth hydrolytic or hydrogenolytic cleavage as a final step, with formation of the SO3H group. On evaluation of these compounds for salidiuretic activity in rats orally (po), and in dogs orally and intravenously (iv), a number of highly active substances was found; the best had a threshold dose of 0.02 mg/kg po in dogs. The results are given in tables, and the structure-activity relationships within the series are discussed. Besides the known effect of the phenoxy radical, an outstanding activating effect was shown by the butylsulfonyl and cycloalkylsulfonyl radicals and by the N-methylanilino radical in particular when they were located in the 4-position of the orthanilic acid molecule. The sulfanilic acid isomers corresponding to three of the most active compounds were synthesized and proved to be completely inactive in rats.


Subject(s)
Diuresis/drug effects , Furosemide/analogs & derivatives , Animals , Dogs , Furosemide/chemical synthesis , Glomerular Filtration Rate/drug effects , Natriuresis/drug effects
11.
Eur J Clin Nutr ; 58(2): 212-8, 2004 Feb.
Article in English | MEDLINE | ID: mdl-14749739

ABSTRACT

OBJECTIVE: Visual analogue scales are widely used in appetite research, yet the validity of these scales to evaluate appetite and mood has not been assessed in older subjects. The aim of this study was to determine the relations between food intake and visual analogue scale (VAS) ratings of appetite and nonappetite sensations in healthy older and young subjects. DESIGN: Retrospective combined analysis of four single-blind, randomised, controlled appetite studies. SETTING: All studies were conducted in the University of Adelaide, Department of Medicine, Adelaide, Australia. SUBJECTS: A total of 45 healthy young men (n=24) and women (n=21) aged 18-35 y and 45 healthy older men (n=24) and women (n=21) aged 65-85 y were recruited by advertisement. INTERVENTIONS: Oral, intraduodenal or intravenous administration of treatments which suppressed food intake were compared to control. Up to 90 min after treatment, a test meal was offered and subjects ate freely for between 30 and 60 min. Perceptions were assessed by 100-mm visual analogue scales administered at regular intervals. RESULTS: Food intake at the test meal was positively related to perceptions of hunger, drowsiness, and calmness at both baseline and premeal (r>0.16, P<0.05), and inversely related to premeal ratings of fullness (r> 0.2, P<0.05) in both older and young subjects. Food intake was related to VAS ratings at least as strongly, if not more so, in older as in young subjects. CONCLUSIONS: These observations (i) confirm that food intake is related to perceptions of hunger and fullness as assessed by VAS in healthy older and young subjects, and (ii) suggest that sensations, not obviously associated with appetite, including 'drowsiness' and 'calmness', are also associated with food intake.


Subject(s)
Appetite/physiology , Eating/psychology , Hunger/physiology , Pain Measurement/psychology , Adolescent , Adult , Aged , Aged, 80 and over , Eating/physiology , Energy Intake , Female , Humans , Male , Pain Measurement/statistics & numerical data , Randomized Controlled Trials as Topic , Regression Analysis , Retrospective Studies , Satiation/physiology , Sleep Stages , South Australia
12.
Appl Radiat Isot ; 87: 331-5, 2014 May.
Article in English | MEDLINE | ID: mdl-24331853

ABSTRACT

The dead-layer uniformity of the top surface of two high purity germanium detectors has been studied using a novel automated scanning set-up that allows a fine-grained topography of a detector's top and lateral surfaces. Comparisons between measurements and Monte Carlo simulations allowed implementation of a dead-layer variation into the detector model, which reproduces the measurements results. The effect of the non-uniform dead-layer on activity determinations based on low-energy γ-rays (i.e. below ~100 keV) has been determined to be of the order of 10% or more.

14.
Phys Rev Lett ; 66(16): 2144-2147, 1991 Apr 22.
Article in English | MEDLINE | ID: mdl-10043402
15.
Phys Rev Lett ; 55(7): 750-753, 1985 Aug 12.
Article in English | MEDLINE | ID: mdl-10032437
19.
Phys Rev B Condens Matter ; 52(11): 8028-8041, 1995 Sep 15.
Article in English | MEDLINE | ID: mdl-9979800
20.
Phys Rev B Condens Matter ; 46(11): 7193-7195, 1992 Sep 15.
Article in English | MEDLINE | ID: mdl-10002430
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