Thrombectomy with embed aspiration in acute ischaemic stroke.

BACKGROUND: In addition to stent retrievers, direct aspiration has become a reasonable thrombectomy strategy. OBJECTIVES: We carried out the thrombectomy by guiding the aspiration catheter fully over the clot and performing immediate manual aspiration; we call this procedure "embed aspiration". METHODS: In this prospective, non-randomised, single-centre study, we included all patients treated at a high volume-of-care stroke centre between 2017 and 2018 for the TRIANA (Thrombectomy in Andalusia using Aspiration) registry. Thrombectomy was carried out by embed aspiration. Patients were classified according to the success (eTICI 2b67-2c-3) or failure (eTICI 0-1-2a-2b50) of the procedure. Baseline clinical data and outcomes were compared, and multivariate analysis was performed. RESULTS: The embed aspiration technique was used in 370 patients. Treatment was successful in 90.3% of patients. Mean puncture-to-recanalisation time was 25 minutes. The overall rate of good outcomes (mRS 0-2) at 3 months was 64%. CONCLUSIONS: This study supports real-life evidence that standardised embed aspiration may be an alternative to stent retrievers for thrombectomy.

Inhibitory action of extracellular adenosine 5'-triphosphate on parietal cells isolated from rabbit gastric mucosa.

The effects of the purine nucleotides, adenosine 5'-triphosphate (ATP) and their analogs 2-methylthio ATP and beta, gamma-methylene ATP, as well as those of the pyrimidine nucleotide, uridine 5'-triphosphate (UTP), on acid production in isolated rabbit gastric parietal cells prepared by enzymatic dispersion and enriched by counterflow elutriation were studied. The (14C)-aminopyrine (AP) accumulation method was used as an index of acid production by the parietal cells. In histamine-stimulated parietal cells, ATP and 2-methylthio ATP, but not beta, gamma-methylene ATP or UTP, produced significant and concentration-related inhibition of the histamine-stimulated AP uptake. The rank order of potency of these nucleotides in inhibiting histamine-stimulated AP accumulation was 2-methylthio ATP > ATP > > beta, gamma-methylene ATP, UTP. In contrast to these results, the AP accumulation responses to secretagogues other than histamine such as carbachol and dibutyryl-cAMP, were not significantly modified by ATP and analogs. Pretreatment of parietal cells with indomethacin, a prostaglandin synthesis inhibitor, led to a significant reduction of the inhibitory responses elicited by ATP on histamine-stimulated AP uptake. These data suggest that ATP selectively inhibits the histamine-stimulated gastric acid secretion in rabbits by acting directly on parietal cells; that a component of this action seems to be related with a stimulation of prostaglandin production; and that the antisecretory effect of ATP on isolated rabbit parietal cells may be mediated via P2Y-purinoceptors.

P1(A2/Ra)-purinoceptors may mediate the stimulatory effect of adenosine and adenosine analogs on acid formation in isolated rabbit parietal cells.

The effects of adenosine (ADO) and its analogs 2-chloroadenosine (2CADO) and 5'-N-ethyl-carboxamido adenosine (NECA) on acid production, as measured by the [14C]-aminopyrine (AP) accumulation method, were studied in rabbit gastric parietal cells prepared by enzymatic dispersion and enriched by counterflow elutriation. ADO (1 microM to 1 mM), 2CADO (1 microM to 1 mM) and NECA (0.1 microM to 100 microM) caused significant concentration-related increases on AP uptake by resting parietal cells. The order of potency was NECA >> 2CADO > or = ADO. Histamine and dibutyryl-cAMP (db-cAMP), known secretagogues, stimulated AP accumulation. In both, histamine- and db-cAMP-stimulated parietal cells, ADO, 2CADO and NECA at the above concentration ranges induced concentration-related increases of the respective AP accumulation raised-rates. The rank order of potency in both stimulated conditions was: NECA > 2CADO >> ADO. Cimetidine, a well known H2 histamine receptor antagonist, at concentration of 100 microM caused potent inhibition of histamine-stimulated AP accumulation without affecting the stimulatory responses to db-cAMP. The increases of AP accumulation elicited by NECA, the most potent purine tested, in both resting and histamine- or db-cAMP-stimulated parietal cells were not significantly modified by cimetidine 100 microM. Theophylline (0.1 microM to 10 microM), a non-specific P1-purinoceptor antagonist, caused significant inhibition of the NECA responses in both resting and histamine-stimulated parietal cells. The concentration order of potency of theophylline was: 0.1 microM > 1 microM > 10 microM. These results suggest that there are P1(A2/Ra)-purinoceptors on rabbit parietal cells which mediate the stimulatory effects of adenosine and analogs on gastric acid production.

Effect of adenosine 5'-triphosphate on secretagogue-stimulated (14C)-aminopyrine accumulation by rabbit isolated gastric glands.

The effect of adenosine 5'-triphosphate (ATP) on gastric acid secretion stimulated by histamine, carbachol and dibutyryl-cAMP (db-cAMP) was studied using glands isolated from rabbit gastric mucosa. The (14C)-aminopyrine (AP) accumulation method was used as an index of acid production by the gastric glands. Histamine-stimulated AP accumulation was significantly inhibited by ATP (10 mumol/l-1 mmol/l). The inhibitory action of ATP appeared to be specific, inasmuch as this nucleotide had no significant effect on basal secretion or secretion stimulated by carbachol or db-cAMP. The antisecretory effect of ATP on histamine-stimulated glands was not affected by the P1-purinoceptor antagonist, theophylline. Pretreatment of glands with indomethacin, a well known prostaglandin synthesis inhibitor, led to a significant reduction of the inhibitory responses to ATP. These results show that ATP inhibits the histamine-stimulated AP accumulation by rabbit isolated gastric glands and suggest that this effect is not due to an ectoenzymatic conversion of ATP into adenosine but to a direct effect of ATP which may be mediated via a P2-purinoceptor subtype linked to prostaglandin production.

[Specific inhibition by ATP of histamine-stimulated acid secretion in the gastric glands of the rabbit]. / Inhibición específica por ATP de la secreción ácida estimulada por histamina en glándulas gástricas de conejo.

The influence of adenosine 5'-triphosphate on gastric acid secretion stimulated by histamine, carbachol, dibutyryl-cAMP and the phosphodiesterase inhibitors 8-phenyl-theophylline and rolipram in isolated rabbit gastric glands was studied. Changes oi gastric acid secretion were measured by the aminopyrine accumulation method. Histamine-stimulated acid secretion was significantly inhibited by ATP 1 mM, whereas the secretory responses elicited by carbachol, dibutyryl-cAMP, 8-phenyl-theophylline or rolipram were not. Assays with indomethacin, a well known prostaglandin synthesis inhibitor, showed that this agent significantly reduced the inhibitory effect of ATP on histamine responses. The results indicate that the antisecretory effect of ATP was specific for histamine and that it was mediated, at least in part, via stimulation of endogenous prostaglandin production.

Characterization of the effects of adenosine, adenosine 5'-triphosphate and related purines on acid secretion in isolated rabbit gastric glands.

The influence of adenosine, AMP, ADP, ATP, the adenosine analogue L-PIA and the ATP analogue beta,gamma-methylene ATP, on gastric acid secretion, as measured by the aminopyrine accumulation method, in resting and histamine-stimulated glands isolated from rabbit gastric mucosa was studied. In resting glands, adenosine and its analogue L-PIA (10 microM-1 mM) caused significant concentration-related increases of the basal H+ secretion, whereas no changes were obtained in response to the other purines tested. In histamine-stimulated glands, adenosine, L-PIA and AMP (10 microM-1 mM) induced concentration-related increases of the H+ secretory rate, whereas ATP, beta,gamma-methylene ATP and ADP (10 microM-1 mM) produced concentration-related decreases of the H+ raised rate. The rank order of potency of the purine compounds in increasing the stimulated H+ secretion was: adenosine greater than L-PIA much greater than AMP, and in decreasing it was: ATP much greater than ADP greater than beta,gamma-methylene ATP. The stimulatory responses to adenosine were inhibited by theophylline (10 microM-100 microM) and caffeine (10 microM-1 mM); whereas, the inhibitory responses to ATP were significantly reduced by the well known prostaglandin synthesis inhibitor indomethacin (1 microM-100 microM). From the results it is concluded that in isolated rabbit gastric glands, purine compounds are effective modulators of the gastric H+ secretory process. The pattern of purine activity obtained suggests that the stimulatory responses, inhibited by methylxanthines, may be mediated via P1-purinoceptors, while the inhibitory responses, reduced by indomethacin, may be mediated via P2-purinoceptors.

[Effects of various physiologic adenine derivatives on the secretion of acid in isolated gastric glands in rabbits]. / Efecto de algunos derivados fisiológicos de la adenina sobre la secreción de ácido en glándulas gástricas aisladas de conejo.

The physiological adenine derivatives, adenosine (ADO), adenosine 5'-monophosphate (AMP), adenosine 5'-diphosphate (ADP) and adenosine 5'-triphosphate (ATP) at concentrations ranging from 10 microM to 1 mM caused concentration-related modifications on gastric H+ secretion, as measured by the aminopyrine accumulation method, in resting and histamine-stimulated rabbit gastric glands. In resting glands, ADO caused significant concentration-related increases of the basal H+ secretion, whereas no changes were obtained in response to the other purines tested. In histamine-stimulated glands, ADO and AMP caused concentration-related potentiation of the histamine-raised H+ secretory rate, while ATP and ADP induced graded inhibition. The results suggest the involvement of purinergic mechanisms in the physiological regulation of the gastric acid secretory process.

[Effect of various adenine derivatives on gastric acid secretion in the isolated rat stomach]. / Efecto de algunos derivados de la adenina sobre la secreción gástrica de ácido en estómago aislado de rata.

The adenine derivatives adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP), adenosine 5'-monophosphate (AMP) and adenosine (AD), in concentrations of 10(-3)M and 10(-4)M caused significant and dose-related modifications in the basal acid secretion from isolated whole rat stomach. The first three purine derivatives, ATP, ADP and AMP significantly increased the spontaneous acid secretion. On the other hand, AD caused a significant reduction in the basal acid secretion. When ATP, ADP, AMP and AD were assayed in the presence of the adrenergic and cholinergic blocking agents, ergotamine, 10(-6)M, propranolol, 5 X 10(-7)M and atropine, 10(-6)M, all these purine derivatives, including AD, caused a significant increase in the basal acid secretion.

Effect of the H1-histamine-like agonist material extracted from bovine spleen on 3': 5'-cyclic nucleotides content in guinea-pig ileal smooth muscle.

The effect of a water-soluble "histamine-free" splenic material that mimics the H1-receptor mediated contractile action of histamine on the guinea-pig ileum has been studied upon concentrations of cGMP and cAMP in slices of this smooth muscle preparation. The splenic extract induced a rapid and sustained decrease in the concentration of cGMP accompanied by a slow decrease in cAMP content in the ileal tissue. These results indicate that the smooth muscle-stimulating agent in splenic extract had no increasing effect on cGMP content as could be expected from the hypothesis that cGMP and cAMP might mediate the smooth muscle contraction and relaxation respectively. The data are not compatible with the general hypothesis that the action of histamine and histamine-like agonists on H1-receptors is associated with an increased concentration of cGMP.

H1-histamine receptors may mediate the contractile response of guinea-pig ileum to 'histamine-free' splenic extracts.

A water-soluble splenic factor, which produces a contractile response of the guinea-pig ileum, that is resistant to cholinoceptor and adrenoceptor antagonists is described. The ileal contractions elicited by the splenic extract showed some significant differences from those elicited by 5-hydroxytryptamine. The responses to splenic extract were not affected by the D-tryptamine-receptor antagonist, methysergide. The effect of the splenic extract on the guinea-pig ileum was similar to that of histamine. The H1-histamine antagonists, (+)-chloropheniramine and diphenhydramine, caused a parallel shift to the right of the splenic extract dose-response curve without suppression of the maximum response. A pA2 value of 8.97 +/- 0.03 for (+)-chloropheniramine and 7.55 +/- 0.1 for diphenhydramine was calculated. Significant histamine levels, as determined by fluorometric methods, could not be detected in the splenic extract. Likewise, the splenic factor did not release histamine from the intestinal preparation. These results support the view that: (i) the splenic factor acts through H1-histamine receptors; (ii) it is not histamine; (iii) it does not have any histamine releasing effect on the ileal smooth muscle.