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Biomedical subjects

R Valero

Publications and source records attributed to R Valero.

At least 19 recordsLinked to original sources
PubMed2001

Hepatic xanthine levels as viability predictor of livers procured from non-heart-beating donor pigs.

BACKGROUND: The aim of the present study was to evaluate hepatic content of adenine nucleotides and their degradation products in non-heart-beating donor (NHBD) pigs and its relationship with recipient survival. METHODS: Thirty animals were transplanted with an allograft from NHBDs. After warm ischemia (WI) time (20, 30, or 40 min), cardiopulmonary bypass and normothermic recirculation (NR) were run for 30 min. Afterward, the animals were cooled to 15 degrees C and liver procurement was performed. RESULTS: Survival rate was 100% in the 20WI, 70% in the 30WI, and 50% in the 40WI. Livers from non-surviving animals had higher levels of xanthine after NR than livers from surviving animals. Logistic regression analysis revealed that xanthine at the end of NR was the only variable able to predict survival with a calculated sensitivity of 80% and a specificity of 60%. Prolongation of warm ischemic period leaded to a greater xanthine accumulation as well as increased plasma alpha-glutathione S-transferase levels at reperfusion. Xanthine at NR and alpha-glutathione S-transferase at reperfusion significantly correlated, indicating that donor xanthine contributes to some extent to the severity of the lesion by ischemia-reperfusion. CONCLUSIONS: It is suggested that xanthine content in the donor is able to predict survival after transplantation. Xanthine is significantly involved in the hepatic lesion elicited by warm ischemia and subsequent ischemia-reperfusion associated to liver transplantation from a NHBD.

Animals↗
PubMed2001

[A case of Carney syndrome].

The Carney complex is an autosomal dominant syndrome characterised by multiple neoplasies, including myxomas at various sites (cardiac, cutaneous, mammary), spotty pigmentation, endocrine overactivity (Cushing's syndrome, acromegalia), testicular tumours and schwannomas. This report describes the case of a 43-year-old woman with an acute inferior myocardial infarction, probably due to coronary embolization from a large left atrial myxoma and who presented this association. A brief review of the Carney complex is provided after discussion of this rare case that required an screening of family members.

Adult↗
PubMed2001

Episodic high irrigation pressure during surgical neuroendoscopy may cause intermittent intracranial circulatory insufficiency.

Intermittent high peak pressure values inside the endoscope during neuroendoscopic surgical procedures are associated with postoperative morbidity. Unexpected delay in awakening is the complication most frequently observed by the anesthesiologist as a result of high peak pressure values inside the endoscope. During eight neuroendoscopic procedures the authors continuously monitored cerebral hemodynamic function, using a transcranial doppler (TCD) probe fixed on patients' temporal window. We observed that episodes of high peak pressure values inside the endoscope during neuroendoscopic navigation rinsing periods resulted in changes in the TCD wave profile consistent with "near intracranial circulatory arrestlike" wave. No systemic hemodynamic warning signs accompanied these intermittent episodes of severe decrease in cerebral perfusion pressure. When the rinsing liquid was allowed to escape, the pressure inside the endoscope decreased and the TCD wave immediately returned to its previous value. Neuroendoscopic procedures, although classified as minimally invasive surgery, warrant special monitoring that could alert us to a decrease in cerebral perfusion pressure. Middle cerebral artery TCD recording is a reliable and accurate tool for this purpose.

Adult↗
PubMed2000

L-arginine reduces liver and biliary tract damage after liver transplantation from non-heart-beating donor pigs.

BACKGROUND: To evaluate whether L-arginine reduces liver and biliary tract damage after transplantation from non heart-beating donor pigs. METHODS: Twenty-five animals received an allograft from non-heart-beating donors. After 40 min of cardiac arrest, normothermic recirculation was run for 30 min. The animals were randomly treated with L-arginine (400 mg x kg(-1) during normothermic recirculation) or saline (control group). Then, the animals were cooled and their livers were transplanted after 6 hr of cold ischemia. The animals were killed on the 5th day, liver damage was assessed on wedged liver biopsies by a semiquantitative analysis and by morphometric analysis of the necrotic areas, and biliary tract damage by histological examination of the explanted liver. RESULTS: Seventeen animals survived the study period. The histological parameters assessed (sinusoidal congestion and dilatation, sinusoidal infiltration by polymorphonuclear cells and lymphocytes, endothelitis, dissociation of liver cell plates, and centrilobular necrosis) were significantly worse in the control group. The necrotic area affected 15.9 +/- 14.5% of the liver biopsies in the control group and 3.7 +/- 3.1% in the L-arginine group (P<0.05). Six of eight animal in the control group and only one of eight survivors in the L-arginine group developed ischemic cholangitis (P<0.01). L-Arginine administration was associated with higher portal blood flow (676.9 +/- 149.46 vs. 475.2 +/- 205.6 ml x min x m(-2); P<0.05), higher hepatic hialuronic acid extraction at normothermic recirculation (38.8 +/- 53.7% vs. -4.2 +/- 18.2%; P<0.05) and after reperfusion (28.6 +/- 55.5% vs. -10.9 +/- 15.5%; P<0.05) and lower levels of alpha-glutation-S-transferase at reperfusion (1325 +/- 1098% respect to baseline vs. 6488 +/- 5612%; P<0.02). CONCLUSIONS: L-Arginine administration during liver procurement from non heart beating donors prevents liver and biliary tract damage.

Animals↗
PubMed2000

[Outcome after spontaneous subarachnoid hemorrhage. Relationship between admission glycemia and clinical status on admission and on hospital discharge].

BACKGROUND: To determine the relationship between the glycemia on hospital admission after subarachnoid haemorrhage (SAH) and neurological score. PATIENTS AND METHODS: On 44 patients we recorded the glycemia value on admission, coma Glasgow scale (CGS) and Hunt and Hess scale grade (HH), on admission, on discharge and six months later. RESULTS: The patients with HH IV-V and GCS between 3 and 8 had glycemia values higher than patients with HH I-III and GCS between 9 and 15. The patients with HH IV-V on discharge had glycemia values higher than patients with HH I-III. CONCLUSIONS: Glycemia value on admission is related with the acute injury severity and represents a prognosis factor in spontaneous subarachnoid haemorrhage outcome.

Acute Disease↗
PubMed2000

Normothermic recirculation reduces primary graft dysfunction of kidneys obtained from non-heart-beating donors.

Our aim was to analyze the short- and long-term function of kidneys procured from non- heartbeating donors (NHBD) by means of three techniques: in situ perfusion (ISP), total body cooling (TBC) and normothermic recirculation (NR). Fifty-seven potential NHBD were included. Mean warm ischemia time was 68.9 +/- 35.6 min. Forty-four kidneys were obtained from donors perfused with ISP, 8 with TBC, and 8 with NR. Eighteen kidneys (32%) started functioning immediately, 29 (52%) showed delayed graft function (DGF) and 9 (16%) showed primary non function (PNF). The actuarial graft survival rate was 76.4% at 1 year and 56% at 5 years. The patient survival rate was 89.3% at 5 years. Incidence of DGF and PNF was significantly lower in kidneys perfused with NR than those with ISP or TBC (P < 0.01). Duration of DGF was shorter in kidneys obtained through TBC than in kidneys obtained with ISP (P < 0.05). In conclusion, NR reduces the incidence of DGF and may be considered the method of choice for kidney procurement from NHBD.

Adult↗
PubMed2000

Anesthetic management of surgical neuroendoscopies: usefulness of monitoring the pressure inside the neuroendoscope.

Neuroendoscopic procedures are increasing in frequency in neurosurgical practice. We describe the anesthetic technique and the perioperative complications found in 100 neuroendoscopic interventions performed at our institution. Cranial tumor biopsy or retrieval (62%) and cisternostomy for hydrocephalus (33%) were the most frequent indications for neuroendoscopy. The mortality rate was low (1%). Intraoperative complications occurred in 36 patients, with arterial hypertension being the most frequent (53%). Postoperative complications occurred in 52 patients; anisocoria (31%) and delayed arousal (29%) were the most frequent. The pressure inside the endoscope was monitored intraoperatively in the last 47 patients. A saline-filled catheter from a pressure transducer connected to the neuroendoscopy system was used for pressure monitoring. We recorded the highest peak of pressure values measured during each procedure. Twenty-three patients (49%) had peak pressure values >30 mm Hg, 12 patients (25%) >50 mm Hg, and 3 patients >100 mm Hg. Only one patient had hemodynamic changes occurring simultaneously with the pressure changes. We found an association between pressure inside the endoscope >30 mm Hg and postoperative (P = .003) but not intraoperative complications. A relationship was found between surgical duration and postoperative complications (P = .002). Neither the pressure inside the endoscope or the intraoperative morbidity were related to surgical duration. We conclude that there may be a high rate of postoperative complications after neuroendoscopies, namely, new neurologic deficits. High pressure levels inside the endoscope during neuroendoscopic procedures can occur without hemodynamic warning signs. Pressure values >30 mm Hg are associated with postoperative morbidity, especially unexpected delayed recovery. Measuring the pressure inside the endoscope is technically easy and might be beneficial if performed in all neuroendoscopic procedures. Reducing the incidence of episodes of high peak pressure values might decrease the rate of postoperative complications.

Adult↗
PubMed2000

[Effectiveness of isobaric 0.5% bupivacaine and 5% lidocaine in continuous subarachnoid anesthesia with microcatheters].

OBJECTIVES: To study the clinical effect of two isobaric local anesthetics infused through microcatheters for continuous subarachnoid anesthesia. MATERIAL AND METHODS: Patients undergoing surgery under continuous subarachnoid anesthesia were enrolled prospectively over 12 months. Twenty-seven-gage catheters were inserted through 22 G Sprotte (Intralong) needles. The two isobaric anesthetics (0.5% bupivacaine and 5% lidocaine) were studied in two successive six-month periods. One milliliter of local anesthetic was administered, followed by incremental doses of 0.5 ml until the required anesthetic level was reached. Hemodynamic variables were recorded, as were levels of anesthetic and motor blockade and complications developing during the surgical and postoperative periods. RESULTS: Thirty-one patients were anesthetized with isobaric 0.5% bupivacaine and 40 with isobaric 5% lidocaine. A high blockade was observed in three patients in the bupivacaine group and in 15 in the bupivacaine group (p < 0.05). The highest anesthetic level reached was T4. Hypotension occurred in one patient in the bupivacaine group and in 10 in the lidocaine group (p < 0.05). Blockade was difficult to increase to the appropriate level in 11 lidocaine patients and in one bupivacaine patient, whereas blockade of distal roots was difficult in 13 bupivacaine patients and in 7 lidocaine patients (p < 0.005). The total doses infused were 11.0 +/- 3.0 mg of 0.5% bupivacaine and 95.6 +/- 24.6 mg of 5% lidocaine. CONCLUSIONS: Isobaric 0.5% bupivacaine provides a more predictable anesthetic blockade with greater hemodynamic stability and a lower rate of difficulty in raising the level of blockade than does 5% lidocaine when administered through microcatheters for continuous subarachnoid anesthesia.

Anesthesia, Spinal↗
PubMed2000

[Isobaric 2% lidocaine in continuous subarachnoid anesthesia using microcatheters].

The objective in the study of the clinical effect of isobaric 2% lidocaine for continuous spinal anesthesia with a microcatheter technique. Nine consecutive patients undergoing lower abdominal surgery under spinal anesthesia were enrolled. We inserted 27 G catheters through 22 G Sprotte (Intralong) needles to administer 20 mg of isobaric 2% lidocaine followed by successive doses of 10 mg until the required level of anesthesia was reached. Repeated injections of 10 mg were given during surgery whenever the level of anesthesia fell as much as one metamere, possibly permitting pain to appear. We recorded hemodynamic variables, level of anesthesia and motor block, as well as complications during and after surgery. The technique was used with nine patients, for whom the mean presurgical dose was 32.3 +/- 9.2 mg and the mean total dose was 51.3 +/- 25.3 mg. However, the protocol for administering the local anesthetic was suspended in three patients due to difficulty in maintaining the achieved level of anesthesia, as repeated injections were required, with consequent patient discomfort. In these patients relatively high levels of blockade were required and surgery lasted longer than one hour. The protocol followed with isobaric 2% lidocaine was not effective for continuous spinal anesthesia with microcatheters because of difficulty of maintaining level of anesthesia.

Aged↗
PubMed1999

USP25, a novel gene encoding a deubiquitinating enzyme, is located in the gene-poor region 21q11.2.

We have identified a new gene, USP25, spanning over 150 kb at 21q11. 2, one of the lowest gene-density regions of the human genome. USP25 is made up of 25 exons and encodes a 1087-aa protein. Database comparisons reveal high homology with members of the ubiquitin protease family (UBP). Basal expression was observed in all human tissues tested, and two main transcripts were identified. The homologous murine gene has also been characterized. In situ hybridization in mouse embryonic brains showed a clear correlation of expression with proliferative neuroepithelial cells and postmitotic neurons. Moreover, high expression was observed in adult mouse testis. UBPs belong to a complex family of deubiquitinating enzymes that specifically cleave ubiquitin conjugates on a great variety of substrates. These enzymes have an essential role in protein degradation via the 26S proteasome and thus regulate many cellular pathways. An increase in USP25 gene dosage in Down syndrome patients could seriously disturb the balance between ubiquitinated and deubiquitinated substrates.

Amino Acid Sequence↗
PubMed1999

Evaluation of ischemic injury during liver procurement from non-heart-beating donors.

UNLABELLED: The aim of this study was to assess liver viability after different periods of cardiac arrest and the predictive value of two markers of ischemia-reperfusion injury. METHODS: A pig liver transplantation model of non-heart-beating donors was studied. Four donor groups were designed; three groups were submitted to different periods of cardiac arrest (20, 30 and 40 min), and the fourth group served as the control group (without cardiac arrest). In the non-heart-beating donor groups, normothermic recirculation was established 30 min prior to total body cooling. Aminotransferase, alpha-glutathione-S-transferase, and hyaluronic acid determinations as well as liver biopsies, were serially performed. RESULTS: Although hepatocellular function could be preserved after 40 min of cardiac arrest, histological lesions at 5 days were considered irreversible due to the presence of a necrotic biliary tract. An overall significant relationship was found between the time period of cardiac arrest (20, 30 or 40 min) and the levels of hyaluronic acid (p = 0.004) or alpha-glutathione-S-transferase (p = 0.01) obtained during liver procurement and transplantation. CONCLUSIONS: The period of cardiac arrest is the determinant factor of liver viability after liver transplantation from non-heart-beating donors. As early markers of endothelial or hepatocellular damage, hyaluronic acid or alpha-glutathione-S-transferase levels may help to evaluate the ischemic injury of a potential donor.

Alanine Transaminase↗