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  • Cyclic AMP  (3)
  • Hyperparathyroidism  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 352 (1995), S. 386-393 
    ISSN: 1432-1912
    Keywords: Brain slice ; Patch-clamp ; Rabbit ; Cyclic AMP ; Potassium current ; Histamine receptors Olfactory bulb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Effects of histamine, histamine agonists and antagonists on steady state current in principal neurons and interneurons were investigated in thin slices from the olfactory bulb of newborn rabbits with the nystatin perforated patch-clamp technique and local pipette application. No change in steady state current was observed in mitral cells. In most of the periglomerular, juxtaglomerular and granular cells, however, H1-receptor activation caused an outward current; a similar effect, but mostly not on the same neurons was elicited by 8-bromo-cyclic-AMP. These currents were reversed at the potassium equilibrium potential and blocked by apamin and therefore probably represent calcium sensitive potassium currents. H2-receptor activation caused an inward current which also reversed at the potassium equilibrium potential, indicating block of a potassium current. Specific H3-receptor activation and cyclic GMP were ineffective. Histamine usually caused a combined effect beginning with an inward current. Histaminergic neurons fire with changes in behavioural state and can, by the described mechanisms, markedly influence signal processing in the olfactory bulb.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Naunyn-Schmiedeberg's archives of pharmacology 352 (1995), S. 386-393 
    ISSN: 1432-1912
    Keywords: Key words Brain slice ; Patch-clamp ; Rabbit ; Cyclic AMP ; Potassium current ; Histamine receptors ; Olfactory bulb
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Effects of histamine, histamine agonists and antagonists on steady state current in principal neurons and interneurons were investigated in thin slices from the olfactory bulb of newborn rabbits with the nystatin perforated patch-clamp technique and local pipette application. No change in steady state current was observed in mitral cells. In most of the periglomerular, juxtaglomerular and granular cells, however, H1-receptor activation caused an outward current; a similar effect, but mostly not on the same neurons was elicited by 8-bromo-cyclic-AMP. These currents were reversed at the potassium equilibrium potential and blocked by apamin and therefore probably represent calcium sensitive potassium currents. H2-receptor activation caused an inward current which also reversed at the potassium equilibrium potential, indicating block of a potassium current. Specific H3-receptor activation and cyclic GMP were ineffective. Histamine usually caused a combined effect beginning with an inward current. Histaminergic neurons fire with changes in behavioural state and can, by the described mechanisms, markedly influence signal processing in the olfactory bulb.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1432-2013
    Keywords: Hippocampal slice ; Low Ca field bursts ; Monoamines ; Cyclic AMP ; Cholinomimetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The influence of monoamine transmitter candidates, acetylcholine and related substances on rhythmic depolarization shifts (field bursts) in the CA1 area of hippocampal slices from rats in low calcium (0.2 mmol·l−1) high magnesium (4 mmol·l−1) was investigated. Acetylcholine (ACh), histamine (HA) and H2-agonists, noradrenaline (NA) and beta-agonists at nano- to micromolar concentrations as well as dopamine (DA) and 8-bromo-cyclic AMP at 100 μmol·l−1 accelerated the field bursts. H2-antagonists blocked HA actions, beta-antagonists blocked NA actions selectively; muscarinic antagonists blocked ACh, HA and NA actions. H1-agonists, serotonin, dopamine and adenosine slowed the field bursts at micromolar concentrations. These effects parallel the action of the tested substances on afterhyperpolarizations in CA 1 pyramidal cells. High sensitivity and specificity make this response of the field bursts an excellent model to study postsynaptic transmitter actions in the central nervous system.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1440
    Keywords: Hyperparathyroidism ; Bone turnover ; Osteitis fibrosa ; Microradioscopy ; Metabolic bone disease ; Hyperparathyreoidismus ; Knochenumsatz ; Fibroosteoklasie ; Mikroradioskopie ; Metabolische Osteopathien
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung 1. Beim primären Hyperparathyreoidismus (PHPT) ist nach heutigem Wissen immer mit einer Skelettbeteiligung zu rechnen. Während bei leichtem PHPT lediglich der Knochenumsatz gesteigert erscheint, führt die schwere Form zur Osteodystrophia fibrosa (=Fibroosteoklasie, FO). Mit Hilfe der Mikroradioskopie (achtfache Lupenbetrachtung feinkörniger, folienloser Materialprüfungsfilme) von Hand-Röntgenaufnahmen können beide Reaktionsformen des Skeletts diagnostiziert werden: die Umbausteigerung an einer vermehrten Striation der Metacarpalia-Corticalis und die Fibroosteoklasie an subperiostalen Usuren der Phalangen. 2. In der vorliegenden Arbeit wurden die präoperativen Befunde von 65 Patienten und die postoperativen von 39 Patienten mit operativ gesichertem primärem Hyperparathyreoidismus verwertet. Striationsgrad (StG) und Usurierungsgrad (UG) wurden mit den biochemischen Parametern des PHPT, der alkalischen Phosphatase als Index der Osteoblastentätigkeit, dem Hydroxyprolin als Größe für den Knochenumsatz, dem radioimmunochemisch bestimmten Parathormon, dem Serum- und Urincalcium, dem Serumphosphor und der Phosphat-Clearance verglichen und auch der Nierensteinhäufigkeit gegenübergestellt. Des weiteren konnte der postoperative Verlauf von Usurierungs- und Striationsgrad verfolgt werden. 3. Bei 60% aller PHPT-Patienten fanden sich pathologische Veränderungen im Röntgenbild, und zwar erhöhter Striationsgrad und/oder erhöhter Usurierungsgrad. In 41,5% der Fälle konnte die Diagnose des PHPT allein aus dem Röntgenbild gestellt werden. Usurierungsgrad und Striationsgrad einerseits korrelierten gut mit alkalischer Phosphatase, Hydroxyprolin und Parathormon andererseits. Dagegen bestand keine Beziehung zwischen der Fibroosteoklasie und der Anamnese einer Nephrolithiasis. Nach Korrektur des PHPT verschwanden die subperiostalen Usuren immer, während bei der Hälfte der Operierten die intracorticalen Striationen über Jahre persistierten, obwohl sich der Knochenumsatz normalisiert hatte. Damit scheint der PHPT nicht nur den endostalen Knochenverlust zu verstärken, sondern kann auch ein irreversibles intracorticales Knochendefizit hinterlassen.
    Notes: Summary 1. In primary hyperparathyroidism an increased bone turnover is seen, accompanied by osteitis fibrosa (=fibroosteoclasia, FO) in severe forms of the disease. Both types of bone reaction may be detected by microradioscopy of X-rays of the hand, extensive striation of metacarpal cortical bone indicating increased bone turnover and subperiosteal resorption of phalanges pointing to FO. 2. In the present study 65 patients with proven PHPT were evaluated before and 39 after operation. Microradioscopy was combined with biochemical assessment of hyperparathyroidism including alkaline serum phosphatase (aPh) as an index of osteoblastic activity, hydroxyprolin excretion (HyPro) reflecting bone turnover, immunoreactive parathyroid hormone levels (PTH), serum calcium (SCa), urinary calcium (UCa), serum inorganic phosphorus (SP) and clearance of phosphate (CP). A comparison was made with the incidence of renal stone disease and the degrees of metacarpal striation (StG) and subperiosteal resorption (UG) were followed after operation. 3. Preoperative X-rays of 60% of the PHPT subjects showed increased StG and/or UG, and in 41,5% the diagnosis of PHPT was possible from the X-ray findings only. There existed a significant correlation between StG and UG on one hand and aPh, HyPro and PTH on the other. No correlation, either positive or negative, was seen between FO and the incidence of renal stones. After surgery, subperiosteal bone lesions disappeared in all patients, while intracortical striations persisted in half of the subjects despite the normalised bone turnover. Thus, primary hyperparathyroidism may not only lead to endosteal bone loss but to an irreversible intracortical bone deficit as well.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1435-2451
    Keywords: Hyperparathyroidism ; Renal stone disease ; Hypercalcemia ; Hyperparathyreoidismus ; Nephrolithiasis ; Hypercalciämie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei 100 Patienten mit primärem Hyperparathyreoidismus (pHPT) waren das Serum Calcium und das Parathormon (PTH) meist erhöht, bei 35 Patienten mit Hypercalciämie und Malignomen dagegen das PTH normal oder nicht meßbar. Bei den 100 Patienten mit pHPT fanden wir our in 11 % die klassischen radiologischen Befunde (subperiostale Usuren und Cysten), in 64 % dagegen eine Nephrolithiasis. Postoperativ konnten wir 42 Patienten nachuntersuchen (Beobachtungsdauer 2–12 Jahre). 82% der Patienten mit präoperativer Nephrolithiasis zeigten postoperativ keine Symptome mehr, bei 75 % war auch radiologisch keine Nephrolithiasis mehr nachweisbar; 63 % der Patienten gaben spontan eine sehr deutliche Besserung ihres subjektiven Befindens an.
    Notes: Summary Serum calcium and parathormone (PTH) were almost elevated in 100 patients with primary hyperparathyroidism (pHPT), whereas PTH was normal or undetectable in 35 patients with a malignant tumor and hypercalcemia. Only 11 % of the patients with pHPT presented the classical radiologic signs, e.g., subperiostal resorptions and cysts; in contrast, in 64% of the patients renal stones were found. A follow-up could be performed in 42 patients (2–12years after parathyroidectomy): 82% of the surgically treated patients with preoperative renal stones were free of symptoms; moreover, in 75 % no renal stones could be detected radiologically and 63 % of the patients spontaneously stated that they felt substantially better.
    Type of Medium: Electronic Resource
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