Search results for "Rini"

Host searching in Argulus foliaceus L. (Crustacea: Branchiura): the role of vision and selectivity.

1998

In laboratory experiments, the swimming behaviour of the ectoparasite Argulus foliaceus and its infection rates on juvenile perch (Perca fluviatilis) and roach (Rutilus rutilus) were examined. The highest infection rate and a preference for perch juveniles were obtained in darkness, the lowest infection rate and a lack of preference in the light, when aquaria with glass walls (high reflectivity) were used. In the light, when aquaria were lined with black plastic (low reflectivity) an intermediate level of infection for perch and the highest for roach was recorded. Under such conditions roach were significantly more heavily infected than perch; an attack rate 4 times greater was recorded for…

Reproductive, biochemical, physiological, and population responses in perch (Perca fluviatilisL.) and roach (Rutilus rutilusL.) downstream of two ele…

2001

Perch (Perca fluviatilis L.) and roach (Rutilus rutilus L.) populations in a state of late vitellogenesis were studied downstream of two pulp and paper mills and at upstream references in southern Lake Saimaa, Finland. The mills used elemental chlorine-free bleaching and activated sludge effluent treatment technologies. The exposure of fish to pulp mill effluents, as measured by concentrations of chlorophenolics in the bile and liver ethoxyresorufin-O-deethylase (EROD) activity, was low and almost similar to the references. Nevertheless, bile resin acid concentrations in exposed perch and roach (260-320 micrograms/ml) and bile beta-sitosterol concentrations in exposed roach (1.5-3.5 microgr…

Scriptum super IV libros Sententiarum. Liber 1

Ms. il·luminat Títol donat pel catalogador Col·lació: Pergamí, f. iii (paper del segle XVI) + 141 + iii (paper del segle XVI) ; foliació moderna a llapis ; reclams horitzontals cada dotze fulls ; algunes signatures de quadern Composició: Escrit a dues columnes a 48 línies (f. 1rb) Escriptura: Gòtica textual cal·ligràfica. Escrit per diverses mans. Anotacions marginals coetànies i posteriors Decoració: Caplletres miniades i decorades, calderons i titolets alternant en blau i vermell Enquadernació: Mudèjar original, pell marró sobre fusta, amb ferros freds. Amb ferros daurats el títol: "I Scriptum Sum" i escut d'armes del Duc de Calàbria flanquejat per les inicials "BTFG". Conserva fragments …

Novel modes of rhythmic burst firing at cognitively-relevant frequencies in thalamocortical neurons.

2008

It is now widely accepted that certain types of cognitive functions are intimately related to synchronized neuronal oscillations at both low (alpha/theta) (4-7/8-13 Hz) and high (beta/gamma) (18-35/30-70 Hz) frequencies. The thalamus is a key participant in many of these oscillations, yet the cellular mechanisms by which this participation occurs are poorly understood. Here we describe how, under appropriate conditions, thalamocortical (TC) neurons from different nuclei can exhibit a wide array of largely unrecognised intrinsic oscillatory activities at a range of cognitively-relevant frequencies. For example, both metabotropic glutamate receptor (mGluR) and muscarinic Ach receptor (mAchR) …

Validation of Fenoterol to Study β<sub>2</sub>-Adrenoceptor Function in the Rat Urinary Bladder

2021

Fenoterol is a β<sub>2</sub>-adrenoceptor (AR)-selective agonist that is commonly used to investigate relaxation responses mediated by β<sub>2</sub>-AR in smooth muscle preparations. Some data have questioned this because fenoterol had low potency in the rat urinary bladder when a muscarinic agonist was used as a pre-contraction agent and because some investigators proposed that fenoterol may act in part via β<sub>3</sub>-AR. We designed the present study to investigate whether fenoterol is a proper pharmacological tool to study β<sub>2</sub>-AR-mediated relaxation responses in the rat urinary bladder. Firstly, we have compared the effect of p…

Muscarinic acetylcholine receptor trafficking in streptolysin O-permeabilized MDCK cells.

1996

We investigated the validity of streptolysin O (SLO)-permeabilized Madin-Darbin canine kidney (MDCK) cells which express muscarinic acetylcholine receptors (mAChRs) coupled to pertussis toxin-sensitive guanine nucleotide-binding proteins (G proteins) for the study of the molecular machinery that regulated mAChR internalization and recycling. Exposure of SLO-permeabilized cells to carbachol-reduced cell surface receptor number by up to 40% without changing total receptor number. The kinetics and maximal extent of receptor internalization as well as the potency of carbachol to induce receptor internalization were almost identical in SLO-permeabilized and non-permeabilized cells. Using this se…

Murine embryonic stem cell line CGR8 expresses all subtypes of muscarinic receptors and multiple nicotinic receptor subunits: Down-regulation of α4- …

2015

Non-neuronal acetylcholine mediates its cellular effects via stimulation of the G-protein-coupled muscarinic receptors and the ligand-gated ion channel nicotinic receptors. The murine embryonic stem cell line CGR8 synthesizes and releases non-neuronal acetylcholine. In the present study a systematic investigation of the expression of nicotinic receptor subunits and muscarinic receptors was performed, when the stem cells were grown in the presence or absence of LIF, as the latter condition induces early differentiation. CGR8 cells expressed multiple nicotinic receptor subtypes (α3, α4, α7, α9, α10, β1, β2, β3, β4, γ, δ, e) and muscarinic receptors (M1, M3, M4, M5); M2 was detected only in 2 …

Apurinic acid, a modified DNA with anticancer activity

1971

Apurinsaure, ein purinfreies hochmolekulares Desoxyribonukleinsaure-Derivat, hemmt das Wachstum des menschlichen Kolontumors GW-77 und das amelanotsiche Melanom des Hamsters.

The variation of acetylcholine release from myenteric neurones with stimulation frequency and train length. Role of presynaptic muscarine receptors.

1983

1. The effects of scopolamine on the release of 3H-acetylcholine (ACh) from the guinea-pig myenteric plexus were studied at different stimulation frequencies (0.03–10 Hz) and train lengths (1–180 pulses). Release of 3H-ACh was measured in the absence of cholinesterase inhibitors as the outflow of tritium from myenteric plexus-longitudinal muscle preparations preloaded with 3H-choline. 2. In control experiments the volley output of 3H-ACh declined with increasing train length and increasing stimulation frequency. Stimulation by one pulse produced the highest volley output. 3. Scopolamine facilitated the evoked output of 3H-ACh via blockade of presynaptic muscarine receptors. A significant in…

Acetylcholine release at motor endplates and autonomic neuroeffector junctions: a comparison.

1996

Acetylcholine released at motor endplates and at autonomic neuroeffector junctions binds to nicotinic and muscarinic receptors to affect the activity of the corresponding target cells. Additionally, nicotonic and muscarinic receptors modulate various intracellular regulatory pathways (second messengers, gene expression) and mediate trophic effects. To maintain homeostasis of the individual cell and of the whole organism the release of acetylcholine has to be strictly controlled within both nervous systems. The basic events of synthesis, storage, and release are comparable at motoneurones and autonomic neurones, but mechanisms regulating transmitter release appear to differ. The motor endpla…