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A Siniscalchi

Publications and source records attributed to A Siniscalchi.

85 records · Page 5Linked to original sources
PubMed1983

Glycine-induced changes in acetylcholine release from guinea-pig brain slices.

The effect of glycine (Gly) on acetylcholine (ACh) release from superfused, resting or electrically-stimulated slices of guinea-pig caudate nucleus (CN), brain stem (BS) and cerebral cortex (CC) was studied. The amino acid 1 X 10(-4)-6 X 10(-3)mol 1(-1) reduced the electrically-induced release and increased the spontaneous and KCl-evoked transmitter outflow, mostly in CN but also in BS, whereas it was ineffective in CC. Taurine, chosen as a structurally related compound, moderately affected only the spontaneous release in CN. Strychnine 2 X 10(-7) mol 1(-1) was per se ineffective, but prevented most Gly effects. The Gly-induced increase of ACh outflow in resting CN slices, however, could be completely antagonized only by administering strychnine and picrotoxin together. These findings suggest that: (i) the overall pattern of Gly influence on cholinergic function is similar to that previously described for gamma-aminobutyric acid (GABA); (ii) specific receptors seem to be present in BS and, above all, in CN; (iii) a positive cooperation between endogenous GABA and Gly is evident in resting CN slices; (iv) the absence of any apparent endogenous glycinergic control on the cholinergic neurones casts doubt on but does not exclude the existence of glycinergic neurones in CN.

Acetylcholine↗
PubMed1982

[Effect of morphine on dopamine and 5-HT content of the caudate nucleus in the guinea pig].

The effect of Morphine (3 x 10(-6) - 3 x 10(-5)) on tissue Dopamine and 5-hydroxytryptamine content was studied in superfused slices of guniea-pig caudate nucleus kept at rest or stimulated for 30 min at 5 Hz. The caudatal slices submitted to electrical stimulation for 30 min showed a significant reduction in their 5-hydroxytryptamine and Dopamine content. Morphine did not modify the amines content of the slices kept at rest but counteracted the depletion caused by electrical stimulation. The opioid was dose-dependent and antagonized by Naloxone 1 x 10(-5) M.

Animals↗
PubMed1982

The effect of naloxone on opioid-induced inhibition and facilitation of acetylcholine release in brain slices.

1 The effect of morphine, methionine-enkephalin (Met-enkephalin) and D-Ala2-D-Leu5-enkephalin (DADLE) were tested on the spontaneous and electrically-evoked release of acetylcholine (ACh) from superfused slices of guinea-pig thalamus, caudate nucleus and cerebral cortex. 2 At no concentration did morphine, Met-enkephalin or DADLE modify the outflow of ACh at rest but Met-enkephalin in the presence of naloxone, reduced the resting ACh release. 3 Morphine, at a low dose (3 microM) had no effect in slices of cerebral cortex, but it enhanced the evoked release of ACh in thalamic and caudate, slices. At higher doses of morphine (10-30 microM), the ACh release evoked by electrical pulses was significantly inhibited in every area. 4 Met-enkephalin behaved like morphine in thalamic slices, whereas DADLE, a specific delta agonist, produced a slight inhibition of ACh outflow only at 10 microM. 5 Naloxone antagonized the inhibitory effect of morphine in the cerebral cortex and caudate nucleus slices. Naloxone and also spiroperidol blocked the releasing effect of morphine in caudate slices. In contrast naloxone did not affect the increase of ACh release caused by morphine and Met-enkephalin in thalamic slices. The inhibitory effect of both opioids at high doses was reversed by naloxone so that they then enhanced ACh release. 6 A two fold increase of calcium concentration in the Krebs solution prevented the inhibitory effects of morphine 10 microM. 7 It is suggested that two receptors are present in thalamic slices, one of which inhibits and the other facilitates ACh release.

Acetylcholine↗
PubMedDate not supplied

Effect of opioid antagonists on acetylcholine release from guinea-pig brain slices: influence of peptidase inhibition.

With the aim of ascertaining the existence of an endogenous opioid control on cholinergic structures, the effects of the opioid antagonists naloxone, Mr 1452, Mr 2266, and ICI 174864 on spontaneous and electrically evoked [3H]choline (Ch) efflux from guinea-pig brain slices were tested. In cerebral cortex and caudate nucleus slices, no drug changed either resting or stimulus-evoked 3H-Ch efflux whether in the absence or in the presence of peptidase inhibitors (thiorphan 0.3 microM, bestatin 10 microM, captopril 10 microM, l-leucyl-l-leucine 2 mM). Conversely, in thalamus slices, the benzomorphan opioid antagonists Mr 1452 and Mr 2266 (but not their non-opioid stereoisomers Mr 1453 and Mr 2267) dose dependently increased St2/St1 ratios, when applied 15 min before St2 to slices superfused with normal Krebs solution. Peptidase inhibition potentiated the facilitatory effect of Mr compounds. Peptidase inhibitors per se reduced the stimulus evoked efflux of 3H-Ch, when present either from the beginning or from 15 min before St2 and potentiated the inhibition induced by dynorphin (Dyn). Mr 2266 fully antagonized any inhibitory effect induced by peptidase inhibitors, Dyn or their combination. ICI 174864, a selective delta antagonist, did not affect 3H-Ch efflux, while naloxone showed a tendency to increase it when peptidases were inhibited. Taken together, these data suggest the existence of an endogenous opioid tone inhibiting acetylcholine release in the guinea-pig thalamus. The relative affinities of the antagonists used suggest that the receptor involved may be of the kappa type.

Acetylcholine↗
PubMedDate not supplied

Twenty-seven consecutive intestinal and multivisceral transplants in adult patients: a 4-year clinical experience.

Adult isolated intestinal and multivisceral transplantation is gaining acceptance as the standard treatment for patients with intestinal failure with life-threatening parenteral nutrition-related complications. We report our 4-year experience with intestinal and multivisceral transplantation. We performed 20 isolated small bowel and seven multivisceral ones, including three with liver. The underlying diseases were mainly short bowel syndrome due to intestinal infarction, chronic intestinal pseudo-obstruction, and Gardner syndrome. Indications for transplant were loss of central venous access in 14 patients, recurrent sepsis in eight patients, and major electrolyte and fluid imbalance in five patients. One-year patient actuarial survival rate was 94% for isolated intestinal transplants and 42% for multivisceral recipients (P = .003), while 1-year graft actuarial survival rate was 88.4% for isolated small bowel patients and 42.8% for multivisceral ones (P = .01). The death rate was 18.5%. Our graftectomy rate was 14.8%. Our immunosuppressive protocols were based on induction agents such as alemtuzumab, daclizumab, and antithymocyte globulins. The majority of our complications were bacterial infections, followed by rejections and relaparotomies; most rejection episodes were treated with steroid boluses and tapering. We believe that our results were due to optimal candidate and donor selection, short ischemia time, and use of induction therapy. Multivisceral transplantation is a more complex procedure with less frequent clinical indications than isolated small bowel transplant, but our data concerning multivisceral transplants include only a small number of patients and require further evaluation.

Adult↗
PubMedDate not supplied

Right ventricular end-diastolic volume index as a predictor of preload status in patients with low right ventricular ejection fraction during orthotopic liver transplantation.

OBJECTIVE: The objective of this study was to compare the accuracy of 2 variables: pulmonary artery occlusion pressure (PAOP) and right ventricular end diastolic volume index (RVEDVI) as predictors of the hemodynamic response to fluid challenge as well as definition of the overall correlation between RVEDVI and change in PAOP, right ventricular ejection fraction (RVEF), central venous pressure (CVP), and determination of the right ventricular function during orthotopic liver transplantation. MATERIALS AND METHODS: A modified pulmonary artery catheter equipped with a fast response thermistor was used to determine RVEF, allowing calculation of RVEF end-diastolic volume index (EDVI, as the ratio of stroke index [SI] to EF). The above-mentioned hemodynamic measures were taken in 4 phases: T0, after induction of anesthesia; T1, during anhepatic phase; T2, 30' after graft reperfusion; and T3, at the end of surgery. RESULTS: The variation of the REF value was 36 +/- 4% and 39 +/- 6%. Linear regression analysis showed a significant correlation between RVEDVI (range, 133 +/- 33-145 +/- 40 mL/m(2)) and stroke volume index (SVI) in each phase (r(2) = 0.49, P < .01; r(2) = 0.57, P < .01) at T0 and T1, respectively, and at T2 and T3 (r(2) = 0.51, P < .01; r(2) = 0.44, P < .01), respectively. No significant variations in the linear regression analysis between RVEDVI, PAOP, CVP, and RVEF were observed. No relationship was found between PAOP (range, 10 +/- 2-6 +/- 2 mm Hg) and SVI. CONCLUSION: RVEDVI may be the best clinical estimate of right ventricular preload. In fact, minor changes of RVEF have been recorded, confirming that RV function was not altered during uncomplicated orthotopic liver transplantation.

Adult↗
PubMedDate not supplied

Results of intestinal and multivisceral transplantation in adult patients: Italian experience.

PURPOSE: We report our experience with intestinal and multivisceral transplantation in Italy. METHODS: We performed 23 adult isolated intestinal transplants and seven multivisceral ones, three with liver, between December 2000 and June 2005. Indications for transplantation were loss of venous access (n = 14), recurrent sepsis (n = 10), and electrolyte-fluid imbalance (n = 6), 14 of whom also presented with total parenteral nutrition (TPN)-related liver dysfunction. Immunosuppression was based on induction agents like daclizumab (followed by tacrolimus and steroids) in the first period; alemtuzumab or thymoglobulin (with tacrolimus) in a second period after 2002. RESULTS: The mean follow-up was 742 +/- 550 days. Three-year patient actuarial survival rate was 88% for intestinal transplants and 42% for multivisceral (P = .015). Three-year graft actuarial survival rate was 73% for intestinal patients and 42.8% for multivisceral (P = .1). Graft loss was mainly due to rejection (57%). Complications were mainly represented by bacterial infections (92% of patients), relaparotomies (82%), and rejections (72%). Full bowel function without any parenteral nutrition or intravenous fluid support was achieved in 60% of recipients with functioning bowel including 95% on a regular diet. One patient underwent abdominal wall transplantation as well. DISCUSSION AND CONCLUSION: Intestinal transplantation has achieved high rates of patient and graft survival with even longer follow-up. Early referral of patients, especially in cases of TPN-liver disease, is mandatory to obtain good outcomes and avoid high mortality rates on the transplant waiting list. Immunosuppressive management remains the key factor to increase the success rate.

Adult↗
PubMedDate not supplied

Forefoot postoperative continuous pain control by nonelectronic device.

The authors present a system against postoperative pain in forefoot operations, which functions by continuous infusion of anesthetic in the malleolar internal space. The system (Single-Day Baxter Infusor) was utilized in 145 patients who had undergone forefoot surgery. The effectiveness of the method was evaluated by means of a numeric scale (0 to 5) reflecting pain level. The method was effective in controlling postoperative pain in 110 cases (score 0 to 1); 25 cases (score 2) reported pain in the dorsal hallux, in the deep peroneal area, whereas in 10 cases (score 4 to 5 on the scale), nonsteroidal anti-inflammatory drugs had to be administered.

Arthritis, Rheumatoid↗
PubMedDate not supplied

Induction of epileptiform activity by temperature elevation in hippocampal slices from young rats: an in vitro model for febrile seizures?

Extracellular field potential recordings were performed in the CA1 subfield of hippocampal slices obtained from Wistar rats aged 2-38 days. When the brain tissue was maintained at 35 degrees-36 degrees C (values obtained in the tissue chamber well), single-shock orthodromic stimuli elicited a response in the stratum pyramidale that consisted of a single population spike. In contrast, when the temperature in the well was increased to levels greater than 38.2 degrees C for periods of 5-15 min, the same type of stimuli elicited an epileptiform response characterized by a 250- to 600-ms-long, positive-going field potential with superimposed, multiple, negative-going population spikes. This potential resembled the epileptiform response recorded in the hippocampal slice in the presence of convulsants such as penicillin or bicuculline. Once the temperature was restored to control values (i.e., 35 degrees-36 degrees C) after induction of epileptiform activity, the abnormal response could be observed for less than or equal to 2 h. In some experiments (approximately one third of the successful trials), spontaneous epileptiform discharges appeared during and persisted after the increase in temperature. The ability of the hyperthermic period to induce epileptiform changes was age dependent: Epileptiform activity outlasting the period of temperature elevation was not observed in slices obtained from rats aged less than 4 days or greater than 28 days. Our data show that epileptiform activity can be induced by a transient increase in temperature and that the age of the animals from which slices are obtained plays an important role in the appearance of this phenomenon.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗