Search results for "Clamp"

Generation of reporter plasmids containing defined base modifications in the DNA strand of choice

2012

Physiological effects of DNA bases other than A, G, C, and T as well as ways of removal of such bases from genomes are studied intensely. Methods for targeted insertion of modified bases into DNA, therefore, are highly demanded in the fields of DNA repair and epigenetics. This article describes efficient procedures for incorporation of modified DNA bases into a plasmid-borne enhanced green fluorescent protein (EGFP) gene. The procedure exploits excision of a stretch of 18 nt from either the transcribed or nontranscribed DNA strand with the help of the sequence-specific nicking endonucleases Nb.Bpu10I and Nt.Bpu10I. The excised single-stranded oligonucleotide is then swapped for a synthetic …

Hypothyroidism and pregnancy. Situation in Latvia

2015

The thyroid gland is the first of the body's endocrine glands to develop, on approximately the 24 th day or 3-4 weeks of gestation, but at around 10-12 weeks the thyroid begins to function on its own. Thyroid hormones are involved in regulation of vital body function. In general normal development, growth and reproduction cannot occur without them. The normal function of thyroid gland is predictor to normal pregnancy outcome and foetus development. It is important to know how many women have hypothyroidism and what kind of treatment they receive. Author selected and made retrospective analysis of women with hypothyroidism maternity cases from 2010 to 2011 year. Data compared to the control …

Heat-induced action potential discharges in nociceptive primary sensory neurons of rats.

2009

Although several transducer molecules for noxious stimuli have been identified, little is known about the transformation of the resulting generator currents into action potentials (APs). Therefore we investigated the transformation process for stepped noxious heat stimuli (42-47 degrees C, 3-s duration) into membrane potential changes and subsequent AP discharges using the somata of acutely dissociated small dorsal root ganglion (DRG) neurons (diameteror=32.5 microm) of adult rats as a model for their own peripheral terminals. Three types of heat-induced membrane potential changes were differentiated: type 1, heat-induced AP discharges (approximately 37% of the neurons); type 2, heat-induce…

Second trimester uterine arteries pulsatility index is a function of placental pathology and provides insights on stillbirth aetiology: A multicenter…

2022

Introduction: The aim of this study was to investigate the relationships between maternal vascular malperfusions (MVM) and second trimester uterine arteries pulsatility index (UtA-PI) in cases of stillbirth (SB), compared to live-birth (LB) matched controls. Methods: This was a multicentre, observational, matched case-control study performed at five referral maternity centres over a 4-year period including SB and LB control pregnancies at high-risk for preeclampsia (PE) and/or fetal growth restriction (FGR), matched and stratified for UtA-PI MoM quartiles values of the SB cases. Logistic regression was used to assess the rates of each MVM finding, within each increasing MoM quartile subcate…

Coexpression of heat-evoked and capsaicin-evoked inward currents in acutely dissociated rat dorsal root ganglion neurons.

1997

Noxious heat is able to activate heat-sensitive nociceptors in the skin very rapidly, but little is known about the mechanisms by which heat is transduced. We used the whole-cell patch-clamp technique to study the effects of noxious heat and capsaicin on freshly dissociated rat dorsal root ganglion neurons in vitro. Using temperatures between 41 degrees C and 53 degrees C, 8 of 19 small neurons (phior = 30 microm) exhibited a heat-evoked inward current. All heat-sensitive neurons tested were also capsaicin-sensitive. Moreover, the heat response tended to be enhanced after capsaicin (360 +/- 150 pA versus 125 +/- 45 pA, P0.1, n = 7). Two of five heat-insensitive neurons were excited by capsa…

Does cyclic GMP mediate the negative inotropic effect of acetylcholine in the heart?

1977

DURING vagal stimulation the pacemaker activity of the heart is diminished. The reduction in heart rate is due to a release of acetylcholine (ACh) from the parasympathetic nerve terminals that increases the permeability of the myocardial cell membrane for potassium ions (for review see ref. 1). This is accompanied by a shortening of the action potential duration in atrial muscle and a diminished calcium uptake2, which in turn results in a negative inotropic effect. Voltage clamp experiments in mammalian atrial muscle have shown that with higher concentrations of ACh not only is the potassium current augmented but also the slow inward current of calcium is reduced3. It is not clear how the c…

Experimental Study of Vibrations in Face Milling Cutting

2014

The paper consists of a research in designing and experimental analysis using a face milling cutter with round inserts. A general model for the new cutter is proposed taking into consideration multiple aspects regarding monitoring and controling the milling process. A comparison of measured vibrations when cutting with different parameters for two constructions of the milling head is presented. The objective of this vibration comparison is to verify wether the new design behaves in similar way with the classic and proven concept of insert clamping using a central screw.

Intracellular Na+ concentration influences short-term plasticity of glutamate transporter-mediated currents in neocortical astrocytes.

2012

Fast synaptic transmission requires a rapid clearance of the released neurotransmitter from the extracellular space. Glial glutamate transporters (excitatory amino acid transporters, EAATs) strongly contribute to glutamate removal. In this work, we investigated the paired-pulse plasticity of synaptically activated, glutamate transporter-mediated currents (STCs) in cortical layer 2/3 astrocytes. STCs were elicited by local electrical stimulation in layer 4 in the presence of ionotropic glutamate (AMPA and NMDA), GABAA, and GABAB receptor antagonists. In experiments with low [Na+]i (5 mM) intrapipette solution, STCs elicited by paired-pulse stimulation demonstrated paired-pulse facilitation (…

Preeclampsia is associated with defective production of C1q by invasive trophoblast

2011

Temporally precise control of single-neuron spiking by juxtacellular nanostimulation

2017

Temporal patterns of action potentials influence a variety of activity-dependent intra- and intercellular processes and play an important role in theories of neural coding. Elucidating the mechanisms underlying these phenomena requires imposing spike trains with precisely defined patterns, but this has been challenging due to the limitations of existing stimulation techniques. Here we present a new nanostimulation method providing control over the action potential output of individual cortical neurons. Spikes are elicited through the juxtacellular application of short-duration fluctuating currents (“kurzpulses”), allowing for the sub-millisecond precise and reproducible induction of arbitr…