Adult-to-adult living donor liver transplantation using left lobes: the importance of surgical modulations on portal graft inflow

BACKGROUND

Due to the shortage of available cadaveric organs, living donor liver transplantation (LDLT) has been recently applied extensively in adults. The use of the left lobe should be encouraged because of donor safety, but frequently the metabolic requirements of severely cirrhotic patients are great and subsequent graft dysfunction is encountered after transplantation. The importance of increased portal inflow to the graft in previously severely cirrhotic patients and other hemodynamic changes in LDLT using left lobes are still under debate, as are the surgical modulations to correct them. In this study, we have reported an initial series of adult-to-adult LDLT using left lobes, underlining the hemodynamic changes encountered during the transplant and the surgical modulations we applied to correct them.

METHODS

Eight adult recipients underwent left lobe liver transplantation from living donors. Portal vein pressure and central venous pressure were measured before and after surgical modulation.

RESULTS

We encountered four cases of small-for-size syndrome. Two patients were retransplanted; the other two died. Seventy-five percent of our recipients survived and 50% did not require further surgery.

CONCLUSION

Surgical portal inflow modulation should be considered in cases of left lobe liver transplantation between adults.

Characterization of Ph-negative abnormal clones emerging during imatinib therapy

BACKGROUND

Imatinib is a tyrosine kinase-specific inhibitor widely used for the treatment of chronic myeloid leukemia (CML). Studies reported the occurrence of additional cytogenetic abnormalities in the Philadelphia chromosome (Ph)-negative cell population emerging after treatment-induced suppression of the Ph-positive clone. These abnormalities were described in a relatively high proportion of patients treated with imatinib compared with the anecdotal reports of similar cases in patients treated with other drugs. However, the origin of these abnormalities as well as their biological and clinical significance are unknown.

METHODS

The study involved 13 cases of patients diagnosed with CML carrying cytogenetic abnormalities in their Ph-negative cell population after imatinib treatment. The presence of the markers within the CD34+ stem cell compartment and the cell culture growth were analyzed and patients were followed over time.

RESULTS

CD34+ cells express the cytogenetic markers present in Ph- cells, suggesting a possible involvement of the stem cell population. Cultured cells showed normal growth in all but 1 patient. No growth advantage was demonstrated for the Ph-negative or the Ph-positive clone after cell culture.

CONCLUSIONS

After follow-up of up to 49 months, none of the patients had evolved to myelodysplasia or acute leukemia. Hypothesis regarding the biological and clinical significance of these abnormalities are formulated.

[Prevalence of aneurysm of the interatrial septum in the general population and in patients with a recent episode of cryptogenetic ischemic stroke: a tissue harmonic imaging transthoracic echocardiography study in 5.631 patients]

Cerebral ischemia is among the principal causes of mortality and morbidity in industrialized countries being responsible of 10-12% of all deaths and of an elevated number of permanent disability. The cardio-embolic forms may be responsible of the 30-35% of cerebrovascular acute syndrome, nevertheless in a significant percentage of cases, especially among young people, cerebral ischemic episodes are not induced by these cardio-embolic forms: these cases are defined as cryptogenetic stroke/TIA. In these patients cardiac abnormalities represented by an aneurysm of the interatrial septum (ASA) and by a patent foramen ovale (PFO) have been frequently observed. The purpose of our prospective, study was to evaluate, through transthoracic echocardiography and tissue harmonic imaging (ETT-THI), the prevalence of ASA in the general population (group A) and the prevalence of ASA-FOP in a subgroup of patients with recent episode of cryptogenetic ischemic stroke/TIA (group B). We studied in a prospective manner from January 1 2003 to October 31t 2004 n. 5.631 patients. The presence of ASA was found in 3.2% of patients of group A, while in patients of group B we identified an ASA in 32% and a POF in 42% of the cases. Using a ETT-THI, our study shows in a wide range of a non selected population a prevalence of ASA greater than in previous studies. Such high prevalence in the general population of patients submitted to echocardiography and the higher frequency in subjects with recent cryptogenetic stroke, suggests to search carefully these abnormalities at the level of the interatrial septum using the harmonic imaging method.

Daclizumab and alemtuzumab as induction agents in adult intestinal and multivisceral transplantation: A comparison of two different regimens on 29 recipients during the early post-operative period

INTRODUCTION

Induction therapy has been recently adopted for intestinal transplant.

PATIENTS AND METHODS

We compared during first 30 days post-transplantation 29 recipients, allocated in two groups, treated with Daclizumab (Zenapax) or Alemtuzumab (Campath-1H).

RESULTS

During first month, 45% of Daclizumab recipients experienced six acute cellular rejections (ACRs) of mild degree, while 63% of them developed an infection requiring treatment. We found three acute cellular rejections in 17.6% of Alemtuzumab recipients, two with moderate degree; 64.7% of them required treatment for infection.

DISCUSSION AND CONCLUSIONS

Graft and patient 3-years cumulative survival rate were not significantly different between groups. Alemtuzumab seems to offer a better immunosuppression during first month.

Serotonin modulation of cell excitability and of [3H]GABA and [3H]D-aspartate efflux in primary cultures of rat cortical neurons

The effects of 5-hydroxytryptamine (5-HT) on neuronal excitability, evaluated as depolarization-induced firing rate, and on amino acid release, measured as electrically-evoked [(3)H]GABA and [(3)H]d-aspartate efflux, were investigated in rat primary cortical neuronal cultures. 5-HT displayed a concentration-dependent, bimodal effect on neuronal excitability: at 3-10microM it increased excitability through 5-HT(2A) receptors, and was blocked by the selective 5-HT(2A) antagonist MDL 100907, whereas at 30-100microM it reduced excitability through 5-HT(1A) receptors, and was, in turn, blocked by the selective 5-HT(1A) antagonist WAY 100135. The electrically-evoked [(3)H]GABA efflux was concentration-dependently inhibited by 5-HT (pEC(50)=4.74) and such inhibition was prevented by WAY 100135, but not by GR 55562, a selective 5-HT(1D/B) receptor antagonist. Conversely, 5-HT concentration-dependently increased stimulus-evoked [(3)H]d-aspartate efflux (pEC(50)=4.71). The increase was facilitated by methiothepin and was reversed into inhibition by ICS 205930, a selective 5-HT(3) receptor antagonist. In the presence of ICS 205930, the inhibition induced by 5-HT was prevented by the selective 5-HT(1D/B) receptor antagonist GR 55562, but not by WAY 100135. These findings suggest that 5-HT inhibits GABA release through 5-HT(1A) receptors and exerts a dual modulation on glutamate release, mostly facilitatory (through 5-HT(3) receptors) but also inhibitory (through 5-HT(1D/B) receptors), leading to a prevalently positive modulation of the excitatory signal by amino acid neurotransmitter containing neurons.

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.

Intraoperative coagulation evaluation of ischemia-reperfusion injury in small bowel transplantation: a way to explore

BACKGROUND AND AIM OF STUDY

The success of intestinal transplantation is affected by the extreme susceptibility of the small bowel to ischemia-reperfusion (I/R) injury. Platelet aggregation decreases after reperfusion in small intestinal ischemia and liver transplantation. Thromboelastography (TEG) is a coagulation test performed whole on blood. The aims of this study were to assess coagulation derangements during bowel transplantation to define appropriate modalities of intraoperative coagulation monitoring. A secondary endpoint was to determine whether measurements of coagulation derangements were useful to estimate small intestinal I/R injury.

MATERIALS AND METHODS

We recruited 19 patients who had undergone elective small bowel transplantation for primary short-gut syndrome. We divided our patients into two groups depending on their reperfusion injury as evaluated with a biopsy after reperfusion: group A composed of eight patients who had a reperfusion injury: group B composed of 11 patients who did not experience this problem. We measured five thromboelastogram indicators (r, k, angle, MA, CL30) at defined intervals: dissection phase (T1), vascular anastomoses phase (T2) as well as 30 minutes (T3) and 120 minutes (T4) after reperfusion during the intestinal reconstruction phase.

RESULTS

We did not observe any significant difference between intraoperative blood loss, core temperature, or volume of fluid fresh frozen plasma, or platelet administration. Angle and MA were decreased significantly among patients with reperfusion injury.

DISCUSSION

Patients showed a hypocoagulation pattern during all the manipulations. This derangement did not depend on the ischemia time. In patients with I/R injury the angle and MA did not change during ischemia, but did change significantly upon reperfusion. Several mechanisms may cause coagulation derangements. During the ischemic period, there may be damage to the vascular bed of the ischemic organ. When arterial blood passes through the damaged vascular bed after reperfusion, platelet activation occurs to varying degrees, resulting in reduced platelet function.

CONCLUSION

Further studies are needed to confirm this preliminary work, which was limited by the low number of patients, in order to elucidate relevant mechanisms and develop predictive algorithms.

Acute renal failure requiring renal replacement therapy after orthotopic liver transplantation

OBJECTIVES

Acute renal failure (ARF) is a severe complication in patients undergoing orthotopic liver transplantation (OLT), which predicts a poor outcome. The aim of this study was to analyze risk factors for the development of ARF, including severity of illness, onset time of ARF prognostic factors of outcome, and mortality in a group of critically patients requiring renal replacement therapy (RRT).

METHODS

Retrospective analysis of 240 consecutive liver transplant cases from 1999 to 2001 admitted to the intensive care unit (ICU) was performed to identify risk factors for ARF development after OLT. The analyzed factors were: age, sex, CrS, BUN, diuresis, sepsis, hypovolemia, cardiac failure, nephrotoxic drugs (cyclosporine or FK506, antibiotics), hyperbilirubinemia, associated diseases (DM, CRF), onset time of renal failure and progressiveness, timing of RRT, number of days of RRT, and mortality. We examined variables upon admission to the ICU, before the first RRT, and on the last ICU day before resignation or death. We used Students' t test. Quantitative parameters were expressed as mean values +/- SD.

RESULTS

Of the 240 patients, 20 (8.3%) experienced ARF needing renal replacement therapy during the postoperative period. The results of our study suggested that ARF among patients undergoing RRT conferred an excessive risk of in-hospital death: eight patients died (40%). This increased risk cannot be explained solely by a more pronounced severity of illness.

CONCLUSION

Our results provide strong evidence that ARF presents a specific, independent risk factor for a poor prognosis.

Analysis of cardiovascular, acid-base status, electrolyte, and coagulation changes during small bowel transplantation

The analysis of intraoperative hemodynamic, metabolic, and coagulation disorders of the recipients in relation to the newly reperfused organ during intestinal transplantation is necessary for an optimal patient management during small bowel transplantation (SBT). The interaction may be minor or may lead to postreperfusion syndrome, producing intense hemodynamic instability, important metabolic changes, and coagulation disorders. This research is based upon experience with 27 patients who underwent SBT. We observed significant decreases in PAM and IRVS after reperfusion in accordance with minor changes of mean pulmonary artery pressure, central venous pressure, and pulmonary capillary wedge pressure. The fall in pH upon revascularization was associated with a concomitant rise in partial carbon dioxide pressure probably due to the increased metabolic activity of the new organ. We found a significant increase in K levels, a rise that may be due to the output of metabolic products by the donor intestine. Patients displayed an hypocoagulative pattern, a derangement that did not seem to depend on ischemia time. It is possible that the same factors supporting the initial TEG pattern endure throughout the surgical procedure. The important and significant maximum amplitude indicator variation between the initial value and that after reperfusion may relate to the release of hypocoagulative factors superimposed on background abnormalities. These interesting metabolic disorders presumably reflected graft function and may provide predictive indices for a good outcome.

Combined liver transplants: main characteristics from the standpoint of anesthesia and support in intensive care

Combined transplants with the liver represent a small number of associated pathologies with little chance of resolving with a single transplant. The small case number prevents us from establishing homogeneous criteria for the procedure. The insertion of the Model for End-Stage Liver Disease in the preoperative evaluation of the patients awaiting liver transplant has definitely increased the number of combined liver-kidney transplants, which have reached more significant numbers. The number of heart-liver transplants is still too low to establish the efficacy of the measure. The multiorgan transplant with the liver represents a rare event entrusted to a series of case reports, each one of which has a history unto itself. Our experience in this field includes 14 combined liver-kidney, six combined heart-liver, and two multiorgan transplants with liver among 36 intestine transplants. We have examined the main pre-, intra-, and postsurgical problems for each one of these transplants, particularly relating to the anesthetic and intensive-care aspects.

Surgical approach to complicated intestinal failure for benign disease in adult patients: transplantation or surgical rehabilitation?

Surgical approaches to complicated benign intestinal failure are gaining acceptance, especially in the pediatric population. Less international experience has been obtained in adult patients, who are usually treated with total parenteral nutrition (TPN). An intestinal rehabilitation program was started in our institution with comprehensive medical rehabilitation, surgical bowel rescue, and transplantation. Among 38 adult patients referred by our gastroenterologists for bowel rehabilitation and surgically treated in our institution, 92.2% received TPN on admission. After careful evaluation, 71% underwent transplantation. Five patients died, but 18 recipients were completely weaned off TPN at follow-up. Eleven patients underwent surgical resection of the affected bowel and a subsequent program of intestinal rehabilitation: they were all alive and weaned off TPN at discharge. At a 2-year mean follow-up, deaths occurred only in the transplant population. Therefore, intestinal surgical rescue, if successful, is optimal in adult patients.

Intraoperative Coagulation Monitoring and Small Bowel Transplantation: A Way to Explore

BACKGROUND

The existence of coagulation disorders during intestinal transplantation is getting more important for a correct anesthetic management. Both a condition of hypocoagulation and hypercoagulation can happen during the intraoperative course. Thromboelastography (TEG), a test on whole blood coagulation, allows measurement of different phases of coagulation function. The aims of our study were to evaluate coagulation derangements during bowel transplantation using TEG.

MATERIALS AND METHODS

We measured cold ischemia time in 19 patients who underwent general anesthesia for intestinal transplantation. We measured five TEG indicators (R, K, angle, MA, CL50) at defined intervals: dissection phase (T1), vascular anastomosis phase (T2), 30' (T3) and 120' (T4) after reperfusion during the intestinal reconstruction.

RESULTS

We found a statistically significant difference between MA measured at T1 versus T3 and T4. There was no significant relation between MA derangements and ischemia time.

CONCLUSIONS

Patients showed hypocoagulation pattern during all periods. MA indicator variation between the initial value and the value after reperfusion may relate to release of hypocoagulation factors. We observed important coagulation derangements during small bowel transplantation, particularly on platelet function after graft reperfusion. The derangements did not depend on ischemia time.

Outcome in right living related liver transplantation with branch-patch arterial reconstruction

cRight lobe living liver transplantation is being performed worldwide with increased frequency. Difficult arterial reconstructions are often encountered because of small diameter or discrepancy between arterial stumps. The risk of arterial thrombosis is reported as high as 26%: microsurgical techniques have reduced this rate below 2%, increasing warm ischemia time. We have developed a new branch patch technique in living related liver transplantation using the donor cystic artery to create an enlarged patch anastomosis that enables increase in the vessel's diameter and therefore greater inflow to the liver. We have followed 8 patients treated with this technique. After more than 1 year (mean follow-up: 636 days) we did not observe any arterial thrombosis by Doppler ultrasound performed every 3 months. The mean resistance index was 0.68 (0.57-0.83-). Three patients died with functional graft without signs of thrombosis. We believe that the cystic artery branch patch technique is feasible in all cases. It is fast (mean time: 6.2 min), it allows a shorter warm ischemia time, and there is no increased risk of thrombosis.

Effects of chemical ischemia in cerebral cortex slices. Focus on nitric oxide

Superfused rat cerebral cortex slices were submitted to a continuous electrical (5 Hz) stimulation and treated with sodium azide (1-10 mM) in the presence of 2 mM 2-deoxyglucose ("chemical ischemia"). Presynaptic cholinergic activity, evaluated as acetylcholine release, was inhibited depending on the sodium azide concentrations and on the length of application (5-30 min). Following a 5-min treatment with 10 mM sodium azide, acetylcholine release was reduced to 45+/-2.3%; simultaneously, there was a 15- and 10-fold increase in glutamate and nitric oxide effluxes, respectively. After restoring normal superfusion conditions, acetylcholine release recovered to 70+/-3.1% of the controls; the N-methyl-D-aspartate receptor antagonist MK-801 (10 microM) as well as the nitric oxide scavengers, haemoglobin (20 microM) and 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide (150 microM), improved the recovery in presynaptic activity, showing that both glutamate and nitric oxide play detrimental roles in chemical ischemia. On the other hand, the post-ischemic recovery was worsened by the guanylylcyclase inhibitor 1H-[l,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (10 microM), suggesting that the activation of such a pathway plays a neuroprotective role and that the nitric oxide-induced harmful effects depend on different mechanisms. Chemical ischemia-evoked nitric oxide efflux partly derived from its calcium-dependent endogenous synthesis, since both the intracellular calcium chelator, 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (1 mM), and the nitric oxide synthase inhibitor, N(omega)-nitro-L-arginine methyl ester (100 microM), substantially prevented sodium azide effects. Nitric oxide efflux was only weakly reduced by MK-801 and was not modified by either the L-type calcium channel blocker, nifedipine (10 microM) or the N-type calcium channel blocker omega-conotoxin (0.5 microM), thus suggesting a prevailing intracellular calcium-dependence of nitric oxide production, although a partial extracellular calcium source cannot be ruled out. These findings show that sodium azide plus 2-deoxyglucose treatment is a useful protocol to induce brain ischemia in vitro and underline the involvement of nitric oxide in the complex events following the ischemic insult.

Hospital admissions syndromic surveillance--Connecticut, October 2001-June 2004

INTRODUCTION

The Connecticut Department of Public Health (CDPH) has continuously monitored daily nonelective hospital admissions through a syndromic surveillance reporting system (HASS) since September 2001. Admission diagnoses are categorized into 11 syndromes including one possible indicator of smallpox, fever with rash, and one possible indicator of influenza and pneumonia.

OBJECTIVES

The objectives are to describe findings from systematic investigation of individual admissions attributed to fever and rash and to determine the utility of monitoring pneumonia admissions as an indicator of severe influenza activity during the 2003-04 influenza season.

METHODS

The incidence of admissions for fever and rash illness was determined for a 12-month period, and results of clinical discharge diagnoses were tabulated. Excess admissions for pneumonia by week during the influenza seasons beginning 2001-03 were determined and compared. Trends in admissions from the 2003-04 season were compared with trends from laboratory and sentinel physician surveillance.

RESULTS

A total of 57 admissions for fever and rash illness were reported from 32 acute-care hospitals and verified for an incidence of 1.7 per 100,000 population. Specific clinical diagnoses were made for 29. Many were compatible with the initial clinical presentation of smallpox. Excess admissions for pneumonia during the 2003-04 season occurred concurrently with sharp increases in positive laboratory reports and percentages of visits to physician's offices attributed to influenza-like illness. The 2003-04 influenza season had many more excess admissions than the 2001-02 and 2002-03 seasons.

CONCLUSION

HASS is a useful surveillance tool for rapid detection of sentinel cases of smallpox. Monitoring excess pneumonia admissions during the influenza season appears to be an effective and specific method for determining levels of influenza activity and for quantification of influenza-related morbidity and impact on the hospital system.

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.

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.

Liver Transplantation for Familial Amyloid Polyneuropathy Non-VAL30MET Variants: Are Cardiac Complications Influenced by Prophylactic Pacing and Immunosuppressive Weaning?

BACKGROUND

Cardiac complications represent a cause of morbidity and mortality after liver transplantation among patients with familial amyloid polyneuropathy (FAP), especially for the non-VAL30MET variant types.

METHODS

We retrospectively evaluated 11 recipients from a nonendemic area including 90.9% affected by FAP variants. Preoperative cardiovascular symptoms were present in 81% of patients. An intraoperative pacemaker was placed prophylactically in 90.9% of all recipients. Since tacrolimus has been reported in the international literature to display cardiac toxicity, we evaluated the influence of intraoperative prophylactic pacing and rapid postoperative weaning from tacrolimus, mainly allowed by thymoglobulin on the occurrence of posttransplantation cardiac complications.

RESULTS

One patient received a combined heart-liver transplant, another, living donor liver transplantation. We did not observe any significant intraoperative cardiac complications. Postoperatively, the pacemaker was removed from all patients but 1. Five patients received tacrolimus and steroids; a subsequent, second group of 6 patients (54.5%) was treated with thymoglobulin followed by tacrolimus. At discharge the mean tacrolimus level was 10.6 ng/mL, whereas after 1 month it was 7.5 ng/mL. We observed a case of acute cellular rejection before discharge, which was successfully treated with intravenous steroids and OKT3. After a mean follow-up of 17.4 months (range, 1-31), 2 patients had died (18.1%): 1 due to sepsis and another, to MI. Two recipients experienced cardiac complications (18.1%), namely, the patient who died due to an myocardial infarction and a second one with a tachyarrhythmia, which was treated successfully with beta-blockers and amiodarone.

CONCLUSION

Prophylactic pacing and rapid weaning from immunosuppression are still associated with a significant rate of postoperative cardiac complications.

Outcomes after adult isolated small bowel transplantation: experience from a single European centre

BACKGROUND

Adult isolated small bowel transplantation is considered the standard treatment for patients with life-threatening parenteral nutrition-related complications. Here, we report a 3-year experience in a single European centre between December 2000 and December 2003.

AIMS

To evaluate and discuss pre-transplant and post-transplant factors that influenced survival rates in our series.

PATIENTS

Fourteen patients, with a mean parenteral nutrition course of 27 months, were transplanted. In eight cases they had not experienced any major complication from parenteral nutrition.

METHODS

We described pre-transplant evaluation and inclusion criteria, surgical technique and clinical management after transplant. Immunosuppressive therapy was based on induction drugs and Tacrolimus. We reported survival rates, major complications and rejection events.

RESULTS

One-year actuarial survival rate was of 92.3% with a mean 21-month follow-up (range 3-36 months). We had no intraoperative deaths. One patient (7.2%) died of sepsis following cytomegalovirus enteritis. One patient underwent graftectomy (7.2%) for intractable severe acute rejection. One-year actuarial graft survival rate of 85.1%. One patient (7.2%) affected by post-transplant lymphoproliferative disease is alive and disease-free after 8 months.

CONCLUSION

We believe candidate selection, induction therapy, donor selection and short ischemia time play an important role in survival after small bowel transplantation.

[Outcome of isolated small bowel transplantation in adults: experience from a single Italian center]

AIM

Isolated small bowel transplantation is becoming the treatment of choice for adult patients with serious parenteral nutrition (PN) related complications: we report our three-year experience (December 2000-December 2003) from a single Italian center (Modena-Italy), with one of the larger European series.

METHODS

We transplanted 14 patients, with a previous mean PN course of 27 months and a mean 21-month post-transplantation follow-up (range 3-36 months), obtaining a one-year actuarial survival rate of 92.3% with no intraoperative deaths.

RESULTS

We lost 1 patient (7.2%), died for post-transplantation overwhelming sepsis following Cytomegalovirus (CMV) enteritis. Thirteen patients are alive, with one-year actuarial graft survival rate of 85.1%: 1 patient underwent graft removal (7.2%) for intractable severe acute rejection. Our immunosuppressive regimen was based on tacrolimus and 3 induction protocols: daclizumab (8 patients) with steroids, alemtuzumab (4 patients) and thymoglobulin (2 patients) without steroids. In 9 cases, we added sirolimus. Nine recipients experienced 22 episodes of acute cellular rejection (ACR), treated successfully in all cases but one. One patient (7.2%) was treated successfully for Post Transplant Lymphoproliferative Disease (PTLD) and is disease-free after 8 months.

CONCLUSIONS

Small bowel transplantation can achieve optimal results depending on appropriate immunosuppressive management and candidate selection, added to shorter ischemia time and careful donor and graft selection.

Effects of nociceptin/orphanin FQ and endomorphin-1 on glutamate and GABA release, intracellular [Ca2+] and cell excitability in primary cultures of rat cortical neurons

The effects of nociceptin/orphanin FQ (N/OFQ) and endomorphin-1 (EM-1) on glutamate and GABA release, intracellular calcium, neuronal excitability and glutamate current were investigated in rat primary cortical neuronal cultures. Through their specific receptors N/OFQ and EM-1 (0.02-1 microM) inhibited the electrically evoked outflow of [3H]D-aspartate at most to -50% and that of [3H]GABA to -30%. In addition, at 1 microM, both peptides induced a decrease of the firing rate caused by electrical depolarization. N/OFQ 1-10 microM did not influence either the electrically evoked calcium influx or the glutamate-evoked currents, whereas EM-1 1 microM significantly inhibited them. Thus, in cortical neurons in culture, both N/OFQ and EM-1 inhibited the secretory process and neuronal excitability but EM-1 also affected calcium influx and cell body responsiveness to glutamate. Consequently, EM-1 appeared to dampen this excitatory signal more then N/OFQ did.

Hospital admissions syndromic surveillance--Connecticut, September 200-November 2003

On September 11, 2001, the Connecticut Department of Public Health (CDPH) initiated daily, statewide syndromic surveillance based on unscheduled hospital admissions (HASS). The system's objectives were to monitor for outbreaks caused by Category A biologic agents and evaluate limits in space and time of identified outbreaks. Thirty-two acute-care hospitals were required to report their previous day's unscheduled admissions for 11 syndromes (pneumonia, hemoptysis, respiratory distress, acute neurologic illness, nontraumatic paralysis, sepsis and nontraumatic shock, fever with rash, fever of unknown cause, acute gastrointestinal illness, and possible cutaneous anthrax, and suspected illness clusters). Admissions for pneumonia, gastrointestinal illness, and sepsis were reported most frequently; admissions for fever with rash, possible cutaneous anthrax, and hemoptysis were rare. A method for determining the difference between random and systemic variation was used to identify differences of >/=3 standard deviations for each syndrome from a 6-month moving average. HASS was adapted to meet changing surveillance needs (e.g., surveillance for anthrax, smallpox, and severe acute respiratory syndrome). HASS was sensitive enough to reflect annual increases in hospital-admission rates for pneumonia during the influenza season and to confirm an outbreak of gastrointestinal illness. Follow-up of HASS neurologic-admissions reports has led to diagnosis of West Nile virus encephalitis cases. Report validation, syndrome-criteria standardization among hospitals, and expanded use of outbreak-detection algorithms will enhance the system's usefulness.

Modifications of plasma concentrations of hormonal and tissue factors during mechanical ventilation with positive end-expiratory pressure

AIM

The aim of this study is to analyse if the decrease of cardiac performance due to positive end-expiratory pressure (PEEP) application, within low values applied in clinical practice (5 cm H(2)O) is able to trigger a response of the main endogenous factors which control and maintain the mean arterial pressure (MAP).

METHODS

This study was applied to 18 patients, admitted to the Intensive Care Unit (ICU) of the University Hospital of Modena, who underwent oro-tracheal intubation and mechanical ventilation. On admission, patients did not suffer from cardiac or lung disease. This study analyses plasma concentrations of epinephrine, norepinephrine, ET-1, NO metabolites, renin, aldosterone at 4 different times: before PEEP application, 60 minutes after the beginning of mechanical ventilation with PEEP, and respectively 30 and 60 minutes after withdrawal of PEEP. At the same time, MAP values and heart rate (HR) have been observed.

RESULTS

Results show an increase of epinephrine and norepinephrine after PEEP application and a decrease to basal values at PEEP withdrawal. All variations are statistically significant. After PEEP introduction, ET-1 showed an increased concentration, although it was not statistically significant, while a significant decreasing trend was observed after PEEP withdrawal. A significant increase of NO metabolite values has been observed together with the increase of ET-1, followed by a decrease to basal values after the withdrawal of PEEP. Concentrations of renin increased when PEEP was applied even though they were not significant and decreased significantly when PEEP was withdrawn. A similar trend was revealed by aldosterone even though it underwent constant significant variations.

CONCLUSION

The administration of PEEP produces an effective response of endogenous substances whose function is to maintain a proper tissue perfusion.

Three-year experience in clinical intestinal transplantation

BACKGROUND

The purpose of this study was to evaluate the outcome of 19 patients who underwent intestinal transplantation (ITx) for intestinal failure.

METHODS

The 19 patients who underwent primary ITx between December 2000 and May 2003 were prescribed three different immunosuppressive protocols that included daclizumab, alemtuzumab, and antithymocyte globulin induction, respectively. A mucosal surveillance protocol for early detection of rejection consisted of zoom video endoscopy and serial biopsies associated with orthogonal polarization spectral imaging. Retrospective review of the clinical records was performed to assess the impact of new modalities of immunosuppression and intestinal mucosal monitoring on patient outcomes.

RESULTS

All patients were adults (mean age 35.8 years). Etiology of intestinal failure included chronic intestinal pseudo-obstruction (n = 6), intestinal angiomatosis (n = 1), Gardner syndrome (n = 2), intestinal infarction (n = 8), radiation enteritis (n = 1), and intestinal atresia (n = 1). All patients experienced complications from total parenteral nutrition (TPN). Thirteen patients (68.4%) received isolated small bowel, whereas six (31.6%) received multivisceral grafts with or without the liver. Thirteen of 19 patients experienced at least one episode of rejection (68.4%). Most ACR episodes were treated with steroid boluses and resolved completely within 5 days. The overall 1-year patient survival was 82%. All living patients are in good health with functioning grafts having been weaned off TPN after a mean of 23.7 days post-ITx.

DISCUSSION

Advances in immunosuppressive therapy with early detection and prompt treatment of rejection episodes make ITx a valuable treatment option for patients with intestinal failure and TPN-related life-threatening complications.

[Tolerability of riluzole: a review of the literature]

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease with the fatal evolution. Recent studies in knowledge of the pathogenic mechanisms underlying ALS showed that the excitotoxicity has an important role in the neurodegeneration. The riluzole, an antagonist of glutamate, is the first drug approved by FDA for the treatment of patients with ALS. The efficacy of riluzole (dose recommended 50 mg twice a day) in prolonging the survival of patients with ALS has been demostrated in two principal controlled clinical trials. The most frequent adverse events related to riluzole treatment were: nausea, vomiting, anorexia, diarrhea, asthenia, somnolence, vertigo, circumoral paresthesia, abdominal pain and dizziness. Some events tend to be related to the dose: vertigo, diarrhea, nausea, circumoral paresthesia and anorexia appear more frequently with 200 mg/die that with lower dose. Generally with tree months from the beginning of the treatment with riluzole, an increase serum transaminase levels has been noted; mostly transient and regressing after two-sex months of treatment. A monitoring of serum transaminase levels is suggested during the first year of treatment with riluzole The clinical studies shows that the adverse events produced by riluzole are mostly reversible and dose-dependent, this demostrates a satifying profile of tolerability of the drug. Anyway, a deeper knowledge of its tolerability may lead us to a better use of riluzole, avoiding in this way the interruption of treatment.

Intraoperative effects of combined versus general anesthesia during major liver surgery

AIM

The study compares the intraoperative effects of combined versus general anesthesia during major liver surgery.

METHODS

In this prospective randomized study, 70 patients were divided into 2 group of 35 subjects. Group A received general anesthesia (thiopentone, fentanyl, vecuronium, sevoflurane in a closed circuit) 15 minutes after placement of an epidural catheter (D9-D10) and induction of epidural anesthesia (6 ml 2% naropine). Continuous epidural infusion was initiated before surgical incision and continued with 0.2% naropine (7 ml/h) until the end of the operation. Group B received combined intraoperative anesthesia wit fentanyl doses according to hemodynamic parameters and 0.1 mg/kg morphine 30-4 minutes before cutaneous suture. Hemodynamic values were measured at base line (T0), and then at 15, 30, 60, 120 and 180 minutes after induction of general anesthesia (T1, T2, T3, T4 and T5, respectively). On recovery, patients were assessed for pain at rest and on movement reported on a visual analog scale; degree of motor blockade according to the Bromage scale; appearance of side effects; use af analgesic.

RESULTS

A statistically significant decrease in the mean arterial blood pressure (ABP) and heart rate (HR) was noted within each group at 15 minutes after induction of general anesthesia. Significant differences in ABP were found between the 2 groups at T1 to T5, whereas HR values were substantially similar. The mean intraoperative use of fentanyl was significantly higher in Group B than in Group A, as was that of vecuronium. Pain intensity on recovery in patients who received epidural anesthesia was lower both at rest and on movement; only the patients in Group B required additional analgesics. No motor blockade was observed in either group. Nausea and vomiting were more frequent in Group B; hypotension was more frequent in Group A.

CONCLUSION

The study confirms the safety of locoregional anesthesia in liver surgery, with good hemodynamic stability and absence of major side effects. The lower intraoperative use of opioids and muscle relaxants in patients who received epidural anesthesia confirms the neurovegetative protection this method provides. The data support the hypothesis that greater intraoperative use of opioids may be responsible for the higher incidence of side effects. Therefore, the intraoperative use of combined low-concentration anesthetic agents alone appears to offer a reasonable treatment option that provides adequate pain control at recovery from general anesthesia, with only minor side effects typically associated with analgesic (motor blockade) and opioids (nausea and vomiting). Given the complications associated with the technique, it should be performed by an expert anesthetist.

Hepatic resections for hepatocellular carcinoma (HCC): short and long-term results on 106 cirrhotic patients

To evaluate the short and long term outcome of liver resections for hepatocellular carcinoma in cirrhotic patients. A retrospective analysis was performed on 106 consecutive cirrhotic patients with hepatocellular carcinoma resected between June 1974 and September 2002 at the Department of Surgery "Pietro Valdoni" - University of Rome "La Sapienza" and at the Liver and Multivisceral Transplant Unit of the University of Modena. Univariate and multivariate analyses were performed on several clinicopathological variables to analyze factors affecting the long-term outcome and intrahepatic recurrence. Overall mortality and morbidity were 10.7% and 26% respectively. These rates significantly decreased in the last years: from 1997 to 2002 no hospital mortality has been recorded. After a median follow-up of 19 months (interquartile range: 10-36), tumour recurrence appeared in 25 patients (23,5%). The 1-, 3-, and 5-year overall survival rates were 86,6%, 70,3%, and 60,6%, respectively. The 1-, 3-, and 5-year disease-free survival rates were 86,3%, 58,1%, and 40,7%. On univariate analysis, viral ethiology of cirrhosis (p=0.03), presence of multiple nodules (p=0.02) and vascular invasion (p=0.05) were found to be related to a worse long-term survival. At the multivariate analysis only the viral ethiology of cirrhosis and the presence of multiple nodules were confirmed as indipendent prognostic factors. Early results after hepatic resection for HCC can be improved by using a limited surgical approach. The viral ethiology of cirrhosis, the presence of multiple nodules and vascular invasion negatively affected recurrence rate and long-term survival.

[Living donor liver transplantation, adult to adult]

AIM

Since living donor liver transplantation (LDLT) can offer a viable response to the lack of transplantable cadaveric organs, our center instituted an LDLT program in 2001.

METHODS

The authors report their experience with the first 35 LDLT procedures successfully completed at the Liver and Multiorgan Transplant Center of the University of Modena between 9 May 2001 and 21 May 2003. The case series comprised 35 patients, 7 of which received a left-half liver and 1 a left lobe.

RESULTS

The global survival rate was 77.2% (27 out of 35 patients), with a mean follow-up period of 295 days; the survival rate at 1 year was 81%. In 4 cases (11%) retransplantation was performed. The donor demographics are described; all donors returned to their normal activities before transplantation, after a mean follow-up period of 373 days. No intraoperative complications were experienced by the donors, whereas during the postoperative period, 2 donors (5.7%) developed major complications (1 biliary fistula on the cut surface, 1 stenosis of the main bile duct).

CONCLUSION

Our study shows that LDLT can be safely completed in the donor, with good results achieved in the recipient as well. Underlying these results is the accurate pretransplant assessment that continued into the operation itself. Even more important was the demonstrated ability and experience of the surgical team to attain results in the donor which we believe are necessary for carrying forth a LDLT program.

Effects of cholecystokinin tetrapeptide (CCK(4)) and of anxiolytic drugs on GABA outflow from the cerebral cortex of freely moving rats

The effect of cholecystokinin tetrapeptide (CCK(4)) and of different anxiolytic drugs on GABA outflow from the cerebral cortex was investigated in freely moving rats, by using the epidural cup technique. CCK(4) (3-30 microg/kg, i.p.) increased GABA outflow and induced objective signs of anxiety. These neurochemical and behavioral responses were prevented by the CCK(B) antagonist GV150013 at 0.1 microg/kg (i.p.). At higher doses (up to 30 microg/kg) this compound per se reduced GABA release and caused sedation, suggesting the presence of a CCKergic positive tonic modulation on GABA interneurons. Similarly the GABA(A) receptors modulator, diazepam (2mg/kg, i.p.) and the 5-HT(1A) agonist buspirone (3mg/kg, i.p.) reduced GABA outflow and caused the expected behavioral effects (reduced muscle tone, mild 5-HT syndrome) which were prevented by the respective, selective antagonists, flumazenil (1mg/kg, i.p.) and NAN-190 (3mg/kg, i.p.). These findings support the idea that GV150013, diazepam and buspirone inhibit GABAergic cortical activity, through the respective receptors. This neurochemical effect may represent the end-effect of various anxiolytic compounds affecting the cortical circuitry.

GABA-mediated synchronization in the human neocortex: elevations in extracellular potassium and presynaptic mechanisms

Field potential and extracellular [K(+)] ([K(+)](o)) recordings were made in the human neocortex in an in vitro slice preparation to study the synchronous activity that occurs in the presence of 4-aminopyridine (50 microM) and ionotropic excitatory amino acid receptor antagonists. Under these experimental conditions, negative or negative-positive field potentials accompanied by rises in [K(+)](o) (up to 4.1 mM from a baseline of 3.25 mM) occurred spontaneously at intervals of 3-27 s. Both field potentials and [K(+)](o) elevations were largest at approximately 1000 microm from the pia. Similar events were induced by neocortical electrical stimuli. Application of medium containing low [Ca(2+)]/high [Mg(2+)] (n=3 slices), antagonism of the GABA(A) receptor (n=7) or mu-opioid receptor activation (n=4) abolished these events. Hence, they represented network, GABA-mediated potentials mainly reflecting the activation of type A receptors following GABA release from interneurons. The GABA(B) receptor agonist baclofen (10-100 microM, n=11) reduced and abolished the GABA-mediated potentials (ID(50)=18 microM). Baclofen effects were antagonized by the GABA(B) receptor antagonist CGP 35348 (0.1-1 mM, n=6; ID(50)=0.19 mM). CGP 38345 application to control medium increased the amplitude of the GABA-mediated potentials and the concomitant [K(+)](o) rises without modifying their rate of occurrence. The GABA-mediated potentials were not influenced by the broad-spectrum metabotropic glutamate agonist (+/-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (100 microM, n=10), but decreased in rate with the group I receptor agonist (S)-3,5-dihydroxyphenylglycine (10-100 microM, n=9). Our data indicate that human neocortical networks challenged with 4-aminopyridine generate glutamatergic-independent, GABA-mediated potentials that are modulated by mu-opioid and GABA(B) receptors presumably located on interneuron terminals. These events are associated with [K(+)](o) elevations that may contribute to interneuron synchronization in the absence of ionotropic excitatory synaptic transmission.

Effects of cholecystokinin tetrapeptide (CCK(4)) and anxiolytic drugs on the electrically evoked [(3)H]5-hydroxytryptamine outflow from rat cortical slices

The outflow of [(3)H]5-hydroxytryptamine ([(3)H]5-HT) from electrically stimulated rat cortical slices was measured to ascertain the modulatory role of endogenous cholecystokinin (CCK) on the amine outflow and to test the hypothesis that different anxiolytic compounds inhibit 5-HT secretion. The [(3)H]5-HT outflow evoked at 10 Hz was increased up to +30% by CCK(4) 300-1000 nM, the effect being prevented by the CCK(B) receptor antagonist GV 150013, 3 nM. The limited sensitivity to CCK(4) seemed to depend on 5-HT auto-receptor feedback because pre-treatment with 100 nM methiothepin enhanced the [(3)H]5-HT outflow and lowered the CCK(4) threshold concentration from 300 to 30 nM. In addition, pre-treatment with 1 microM bacitracin to inhibit CCK metabolism increased [(3)H]5-HT efflux. This effect was concentration-dependently counteracted by GV150013 suggesting the presence of an endogenous CCK positive modulation. GV150013 30 nM, the 5-HT(1A) partial agonist buspirone 300 nM and the GABA(A) receptor modulator diazepam 10 nM, known to have anxiolytic properties, all significantly reduced the [(3)H] amine outflow from cortical slices by about 20%. This inhibition depended on their interaction with their respective receptors, which seemed to restrain the activity of functionally interconnected glutamatergic interneurones. In fact, APV (50 microM) and NBQX (10 microM) prevented the effect of the anxiolytic compounds. Thus, anxiolytic drugs with different receptor targets can reduce 5-HT outflow by dampening the glutamatergic signal, and in turn, the secretory process of the serotonergic nerve ending.

Cannabinoid receptor agonist WIN 55,212-2 inhibits rat cortical dialysate gamma-aminobutyric acid levels

The effects of the cannabinoid receptor agonist WIN 55,212-2 (0.1-5 mg/kg i.p.) on endogenous extracellular gamma-aminobutyric acid (GABA) levels in the cerebral cortex of the awake rat was investigated by using microdialysis. WIN 55,212-2 (1 and 5 mg/kg i.p.) was associated with a concentration-dependent decrease in dialysate GABA levels (-16% +/- 4% and -26% +/- 4% of basal values, respectively). The WIN 55,212-2 (5 mg/kg i.p.) induced-inhibition was counteracted by a dose (0.1 mg/kg i.p.) of the CB(1) receptor antagonist SR141716A, which by itself was without effect on cortical GABA levels. These findings suggest that cannabinoids decrease cortical GABA levels in vivo, an action that might underlie some of the cognitive and behavioral effects of acute exposure to marijuana.

Effects of two-carbon bridge region methoxylation of benztropine: discovery of novel chiral ligands for the dopamine transporter

6-Methoxylated and 8-oxygenated benztropines were prepared and evaluated for their DAT and SERT activity (binding and uptake inhibition). Methoxylation at the two-carbon bridge of benztropine produced a novel class of potent and selective DAT ligands. An interesting enantioselectivity was also observed for this new class of chiral benztropines. The inactivity of the 8-oxygenated analogues seems to point out that, unlike cocaine and its analogues, interactions of benztropine ligands with DAT may be strongly governed by the nitrogen atom.

NMDA and AMPA/kainate receptors are involved in the anticonvulsant activity of riluzole in DBA/2 mice

The anticonvulsant activity of riluzole against sound-induced seizures was studied in the DBA/2 mouse model. Riluzole (0.1-4 mg kg(-1), intraperitoneal (i.p.)) produced dose-dependent effects with ED(50) values for the suppression of tonic, clonic and wild running phases of 0.72, 1.38 and 2.71 mg kg(-1), respectively. Riluzole also protected DBA/2 mice from seizures induced by an intracerebroventricular (i.c.v.) injection of N-methyl-D-aspartate (NMDA) with ED(50) values of 3.03 and 5.0 mg kg(-1) for tonus and clonus, respectively. Pretreatment with glycine, an agonist to the glycine/NMDA receptors, shifted the dose-response effect of riluzole to the right (ED(50)=6.53 against tonus and 9.34 mg kg(-1) vs. clonus). Similarly, D-serine, an agonist at the glycine site, shifted the ED(50) of riluzole against the tonic component of audiogenic seizures from 0.72 to 1.97, and that against clonus from 1.38 to 2.77 mg kg(-1). Riluzole was also potent to prevent seizures induced by administration of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA), an AMPA/kainate receptor agonist (ED(50)=1.80 and 3.35 mg kg(-1), against tonus and clonus, respectively). Pretreatment with aniracetam, a positive allosteric modulator of AMPA/kainate receptors, shifted the dose-response curve of riluzole to the right (ED(50)=1.78 against tonus and 2.58 mg kg(-1) vs. clonus). The data indicate that riluzole is an effective anticonvulsant drug in the genetic model of seizure-prone DBA/2 mice. Our findings suggest that the anticonvulsant properties of riluzole depend upon its interaction with neurotransmission mediated by both the glycine/NMDA and the AMPA/kainate receptor complex.

[Cardiac rupture in thoracic trauma]

Thoracic trauma frequently involve damage to the cardiac structures and in the worst cases, the progressive degeneration and necrosis of the damaged tissue lead to cardiac rupture. The high mortality resulting from cardiac tamponade requires the prompt execution of diagnostic tests to provide as much useful information as rapidly as possible in order to start immediate therapy. A case of cardiac rupture manifested by the onset of atrial fibrillation in a patient admitted to Intensive Care after a car accident is described. The scarce significance of objective examination, the aspecific nature of chest X-ray and ECG alterations prompted the execution of a more thorough diagnosis. Transthoracic and transesophageal ultrasonography are both minimally invasive and highly specific: in a short time, not only did they confirm cardiac rupture, but they also focalised the site of the lesion, thus allowing a more targeted and rapid surgical approach. The relative frequency of cardiac lesions following closed thoracic trauma, the lack of incontrovertible signs and symptoms of late cardiac rupture, and the extreme severity of its clinical consequences argue in favour of using specific and sensitive diagnostic tests that can not only exclude or ascertain the presence of these lesions, but also allow subsequent serial controls aimed at diagnosing late cardiac ruptures.

Neurotensin increases endogenous glutamate release in rat cortical slices

In the present study, the effects of the tridecapeptide neurotensin [NT(1-13)] and its fragments, NT(1-7) and NT(8-13), on endogenous glutamate release from rat cortical slices, were evaluated. NT(1-13) (100-1000 nM) slightly increased spontaneous glutamate release, while it was ineffective at 1 and 10 nM concentrations. Neither the biologically active NT fragment NT(8-13) nor the inactive one NT(1-7) affected basal glutamate release. NT(1-13) (1-1000 nM) enhanced potassium (35 mM)-evoked glutamate release displaying a bell-shaped concentration response curve. In addition NT(8-13) (10 nM) increased K+-evoked-glutamate release similarly to the parent peptide (10 nM), while the biologically inactive fragment NT(1-7) (10-100 nM) was ineffective. The effects of NT(1-13) and NT(8-13) were fully counteracted by the selective neurotensin receptor antagonist SR48692 (100 nM). These findings suggest that NT plays a role in regulating cortical glutamate transmission.

New insights on flow-independent mechanisms of 99mTc-HMPAO retention in nervous tissue: in vitro study

SPECT using 99mTc-hexamethyl propyleneamine oxime (HMPAO) mainly reflects regional cerebral blood flow, however metabolic abnormalities also affect the retention of 99mTc-HMPAO.

METHODS

To rule out any flow factor, a test-tube model was used to evaluate the effects of metabolic alterations both on intracellular trapping of 99mTc-HMPAO and on extracellular glutamate and lactate dehydrogenase (LDH) outflow from rat brain slices.

RESULTS

Under control conditions, slices took up 7.0%+/-1.4% of 99mTc-HMPAO contained in the medium, whereas prelabeled slices released 10.8%+/-2.6% of their radioactive content; glutamate and LDH outflow were 49.1+/-21.6 pmol/mg protein/ min and 4.8+/-0.9 U/L/mg protein/min, respectively. The control medium was altered by adding a metabolic poison (5 mmol/L azide), removing glucose and replacing O2 with N2 to mimic ischemia (in vitro ischemia) and replacing Krebs solution with hypotonic medium to evoke cell lysis. Both azide and in vitro ischemia induced a significant increase in 99mTc-HMPAO release (15.8%+/-3.3% and 18.3%+/-6.2%, respectively), without any modification in LDH efflux. However, only azide reduced the uptake of the tracer. Conversely, glutamate outflow was massive during in vitro ischemia and was far lower during azide treatment. Under hypotonic medium conditions, the release of 99mTc-HMPAO, glutamate and LDH were dramatically increased. Surprisingly, a two-fold increase of 99mTc-HMPAO uptake was also found. When 1 mmol/L glutathione was added to the medium, to convert native lipophilic 99mTc-HMPAO into hydrophilic derivatives, tracer uptake was inhibited both under control and hypotonic medium conditions.

CONCLUSION

This study provides evidence that not only poisoning of the tissue but also in vitro ischemia induced a reduction of 99mTc-HMPAO retention. Moreover, we demonstrated that injuries causing cell membrane disruption led to hyperfixation of 99mTc-HMPAO.

Neuroprotective effects of riluzole: an electrophysiological and histological analysis in an in vitro model of ischemia

The protective effects of riluzole against the neuronal damage caused by O2 and glucose deprivation (ischemia) was investigated in rat cortical slices by recording electrophysiologically the cortico-cortical field potential and by evaluating histologically the severity of neuronal death. Five minutes of ischemia determined an irreversible depression of the amplitude of the field potential. In addition, this insult caused a clear enhancement of the number of death cells that were specifically colored with trypan blue (a vital colorant which stains altered cells). We found that riluzole, which by itself depressed the synaptic transmission, neuroprotected when perfused 15-20 min before and during ischemia. In fact, due to the treatment with riluzole, the ischemia-induced irreversible depression of the field potential recovered and less cells were stained with trypan blue. These findings demonstrate that riluzole prevents neuronal death in an in vitro model of ischemia and suggest a therapeutic use of this drug in order to reduce the pathophysiological outcomes of stroke.

Early changes in adenosine A1 receptors in cerebral cortex slices submitted to in vitro ischemia

The effects of brain ischemia on the maximum binding capacity (Bmax) and affinity (Kd) of A1 receptors were studied in the rat cerebral cortex, with an in vitro approach. The results were correlated with changes in 3H-adenosine release, studied under identical experimental conditions. Fifteen minutes of in vitro 'ischemia' (hypoxic, glucose-free medium) induced a significant increase in both Bmax (2398+/-132 fmol/mg protein, 151% of the control, P < 0.05) and in Kd (2.43+/-0.12 nM, 161% of the control, P < 0.01). At the same time, an increase in tritium efflux from [3H]-adenosine labeled cerebral cortex slices to 324% of the control was observed. A trend toward normalization was evident 5-15 min after 'reoxygenation' (restoring normal medium), but the binding parameters were still altered after 60 min (Bmax 2110+/-82 fmol/mg protein, Kd 2.26+/-0.14 nM, P < 0.01 vs the corresponding control) as was adenosine release (196% of the control). These findings suggest that the increased availability of adenosine and its receptors may be a defense mechanism against ischemic injury, while the reduced affinity of A1 receptors, possibly due to desensitization, may be a sign of ischemia-induced cellular damage.

5-HT4 receptor modulation of acetylcholine outflow in guinea pig brain slices

The effect of the 5-HT4 agonist, BIMU-8 was studied on [3H]choline outflow in guinea pig brain slices and synaptosomes. BIMU-8 did not modify [3H]choline efflux in slices kept at rest, but increased [3H]choline outflow in electrically stimulated slices of cerebral cortex (CC), hippocampus (hip) and nucleus basalis magnocellularis (nbm). This effect was prevented by the selective 5-HT4 antagonist, GR 125487. Conversely, BIMU-8 did not affect [3H]choline efflux in hippocampal synaptosomes depolarized with KCl 20 mM. These results provide evidence that BIMU-8 increases the electrically triggered [3H]choline efflux in CC, hip and nbm slices. A possible role of 5-HT4 agonists in memory and learning diseases is suggested.

An electrophysiological analysis of the protective effects of felbamate, lamotrigine, and lidocaine on the functional recovery from in vitro ischemia in rat neocortical slices

We used field potential recording techniques to examine whether felbamate (FBM), lamotrigine (LTG), and lidocaine (LID) protect against the irreversible functional damage induced by transient ischemia. Five minutes of ischemia caused a depression of the field potential in rat cortical slices, which did not recover even after more than 1 h of washout. The N-methyl-D-aspartate (NMDA) antagonist ketamine (50 microM) protected against depression of the field caused by ischemia. On the other hand, the non-NMDA antagonist 6-cyano-7-nitroquinoxaline-2.3-dione (CNQX) (10 microM) had protective effects only if co-applied with ketamine. We found that either FBM (30-300 microM), which did not modify the amplitude of the field EPSP, or LTG (10-300 microM), which reversibly depressed the excitatory synaptic transmission, had a marked protective effect when superfused before and during the ischemic insult. After FBM (100 microM) and LTG (100 microM), the field EPSP recovered by 84 +/- 1% and 73 +/- 2.7% of control, respectively. Furthermore, LID (30-300 microM) was less effective than FBM and LTG in inducing a functional recovery from the damage caused by ischemia (58 +/- 1.8%). The rank order of potency, based on the maximal protection caused by the three drugs, was FBM > LTG > LID. Our results suggest that a noticeable neuroprotection can be obtained during glucose and O2 deprivation by preventive therapeutic regimens which use the two recently marketed anticonvulsant drugs, FBM and LTG.

Experimental protocol for studying delayed effects of in vitro ischemia on neurotransmitter release from brain slices

The mechanisms by which ischemic injury leads to delayed neuronal death are not completely understood. Notably, no data are so far available on the modifications in neurosecretory responses evoked by a period of ischemia. Superfused brain slices represent a useful preparation in studying the effects of in vitro ischemia on neurotransmitter release. Using this experimental model we describe a protocol which allows to study not only the immediate effects of an ischemic insult, but also, more interestingly, its delayed (1 h) effects on the release of different neurotransmitters. A first pulse (S1) of 50 mM KCl was applied at the 60th min of perfusion and a second one was applied at the 210th min (S2). In vitro ischemia was performed from the 120th to the 150th min, during the inclusive period between the two depolarizing stimuli. The delayed effects of the ischemic treatment on slice response to KCl were calculated as S2/S1 ratio. This protocol allows to study neurotransmitter release mechanisms associated with postischemic neuronal death. Moreover it will be useful in the evaluation of the neuroprotective potential of new drugs.

Riluzole interacts with voltage-activated sodium and potassium currents in cultured rat cortical neurons

The actions of the neuroprotective and anticonvulsant agent riluzole on voltage-activated currents were studied in primary cultures of rat cortical neurons by using whole-cell patch-clamp recording techniques. Isolated Na+, Ca2+ and K+ currents were generated in these cells by depolarizing commands from a holding potential of - 80 mV. Riluzole (10-300 microM) reversibly reduced in a dose-dependent manner the inward Na+ currents with an IC50 of 51 microM in all the tested neurons (n=29). This drug also shifted the steady-state inactivation curve of the sodium current towards more negative values (about 20mV, n=15) while it did not change significantly the decay phase of the Na+ current. Furthermore, riluzole (100 and 300 microM; n=5 and n=3, respectively) did not modulate the inward Ca2+ currents evoked by depolarizing steps on cortical cells. An additional concentration-dependent effect of riluzole was observed on the outward potassium currents. In fact, while the amplitude of the peak of the outward current (IA) was not changed significantly, the amplitude of the late component of the outward K+ current (Iss) was markedly decreased during the perfusion of riluzole (IC50=88 microM; n=16). It is concluded that riluzole modulates the Na+- and the late K+-dependent currents in cortical neurons. Both phenomena may explain, at least in part, the anticonvulsant and neuroprotective properties of this compound.

Modification of levodopa responses by deprenyl (selegiline): an electrophysiological and behavioral study in the rat relevant to Parkinson's disease

From using in vitro intracellular recordings from mesencephalic neurons and monoamine-depleted rats, we report that the functions of levodopa in the brain are greatly enhanced and prolonged by high doses of the monoamine oxidase (MAO) inhibitor deprenyl. Dopaminergic neurons were hyperpolarized and inhibited by levodopa application. These effects of levodopa were largely potentiated by pretreatment with nonselective doses of deprenyl. Furthermore, when locomotor activity induced by levodopa was examined on a rodent model of Parkinson's disease, pretreatment of the animals with nonselective doses of deprenyl caused an enhancement of the antiparkinsonian action of levodopa. The great increase in levodopa responses by deprenyl suggests a likely therapeutic use of this dopamine precursor with a higher dosage of the MAO inhibitor, to reduce effectively the daily levodopa requirements in Parkinson's disease patients.

Whole cell patch-clamp recordings of rat midbrain dopaminergic neurons isolate a sulphonylurea- and ATP-sensitive component of potassium currents activated by hypoxia

The effects of brief (2-4 min) hypoxia on presumed dopaminergic "principal" neurons of the rat ventral mesencephalon were investigated by using either intracellular or whole cell patch-clamp recordings in in vitro conditions. Under single-electrode voltage clamp, with sharp microelectrode (Vh -60 mV), a brief hypoxia caused an outward current (hypoOUT) of 110.2 +/- 15.2 (SE) pA (n = 18), which was followed by a posthypoxic outward current (posthypoOUT) of 149.6 +/- 10.6 pA (n = 18). Although the hypoOUT reversed at -83.7 +/- 3.8 mV (n = 18), the posthypoOUT did not reverse. The K+ATP-blocking sulphonylureas tolbutamide (100 microM) and glibenclamide (30 microM), significantly reduced the peak of the hypoOUT by 47.6 +/- 7.7% (n = 16) and 54.18 +/- 7.5% (n = 3), respectively. In contrast, they did not affect the posthypoOUT. Extracellular barium (300 microM to 1 mM) almost abolished the hypoOUT, leaving the posthypoOUT unchanged. The large K+ channel blocker charybdotoxin (10-50 nM), depressed the hypoOUT after tolbutamide treatment. To investigate whether or not cytosolic factors might control the development of the hypoOUT, we dialyzed the principal neurons by patch-clamp recordings (Vh -60 mV). Under whole cell recordings hypoxia evoked an hypoOUT of 70.2 +/- 14.5 pA that reversed polarity at -87.9 +/- 5.1 mV (n = 8). A small posthypoxic response was detected upon reoxygenation in a few neurons (4 out of 14). Three different sulphonylureas, tolbutamide (100 microM), glibenclamide (10-30 microM), and glipizide (100 nM) completely blocked the hypoOUT in patch-clamped neurons. The hypoOUT was also abolished by extracellular BaCl2 (300 microM). When the content of ATP in the dialyzate was raised from 2 to 10 mM no outward current/hyperpolarization was evoked by hypoxia. These data suggest that the hypoOUT, in principal neurons, is a complex response sustained by at least two barium-sensitive components: 1) an ATP-dependent, sulphonylurea-sensitive K+ conductance which could be isolated by the patch-clamp techniques and 2) a K+ conductance remaining after tolbutamide in intracellularly recorded neurons, which is sensitive to charybdotoxin and dependent on dialyzable cytosolic factors.