Pharmacogenetics in critical care: association between CYP3A5 rs776746 A/G genotype and acetaminophen response in sepsis and septic shock

BACKGROUND

Pharmacogenetics could represent a further resource to understand the interindividual heterogeneity of response of the host to sepsis and to provide a personalized approach to the critical care patient.

METHODS

Secondary analysis of data from the prospective observational study NCT02750163, in 50 adult septic and septic shock patients treated with Acetaminophen (ACT) for pyrexia. We investigated the presence of two polymorphisms, located respectively in the genes UGT1A1 and CYP3A5, that encode for proteins related to the hepatic metabolism of ACT. The main dependent variables explored were plasmatic concentration of ACT, body temperature and hepatic parameters.

RESULTS

8% of the patients carried CYP3A5 rs776746 A/G genotypes and showed significantly higher plasma levels of ACT than GG wild type patients, and than patients with UGT1A1 rs8330 C/G genotypes.

CONCLUSIONS

Identifying specific genotypes of response to ACT may be helpful to guide a more personalized titration of therapy in sepsis and septic shock. CYP3A5 might be a good biomarker for ACT metabolism; however further studies are needed to confirm this result.

TRIAL REGISTRATION

NCT02750163.

Sentinel Lymph Node Identification in Breast Cancer: Feasibility Study

The aim of the study was to evaluate in our institute the technique of sentinel node (SN) identification and biopsy in the surgical treatment of early breast cancer. Between June 1998 and November 1999 54 patients (age range, 31–75 years) where studied. Inclusion criteria were age less than 75 years, indication for conservative surgery, absence of palpable axillary nodes, Karnofksy index >70. Lymphoscintigraphy was performed 16–18 hours prior to surgery, following injection of 0.1–0.2 mL of 99mTc-Nanocoll: the administered activity was 3–4 MBq in group A (44 pts) and 7–8 MBq in group B (10 pts). The colloids were administered by transdermal supralesional injection in 49 patients with palpable nodules and by intraparenchymal ultrasound-guided injection in five patients with non-palpable nodules. Planar projections were performed starting from the 5th until the 80th min (or 180th in the event of late migration). In 10 patients further projections were acquired 14–18 h following tracer administration. All nodes identified by gamma probe (MR 100 Pol. Hi. Tech) were histologically evaluated by immunohistochemistry and standard histology. Scintigraphic visualization of the SN was obtained in 49 patients: in 38 of these patients there was only one SN while in 11 patients there were two or three SNs. The delayed scan made in 10 patients did not show any further nodes. In all patients given US-guided perilesional injections migration was late (after at least 60 min). Our study confirms the validity of the scintigraphic procedure, its safety for patients and health care workers, and the feasibility of interdisciplinary collaboration.

In Vitro Evaluation of Bio-Functional Performances of Ghimas Titanium Implants

Titanium is the most widely used material for dental implants. The natural formation, in presence of oxygen, of different oxide films (passivation films) is correlated to titanium implant biocompatibility, resistance to corrosion and is responsible for implant bacteriostatic action. Surface roughness is another surface property of Ti-implants that, affecting implant-to-bone contact, improves integration. In the present study data concerning composition, surface roughness and biocompatibility of Ghimas implants and mini-implants undergoing sandblasting with Calcium Magnesium Carbonate (CaMg(CO3)2) are reported. AFM, SEM/EDX, XRD analyses and morphofunctional tests (MTT and ALP) were performed. Cell actin cytoskeletal modification (fluorescence phalloidin staining) was also observed with confocal laser microscopy (CLSM). Data related to surface geometry and chemical properties, associated with evidence of high purity of all the tested materials (XRD and EDX), highlighted the elevated biocompatibility of tested implants and mini-implants. CLSM investigation confirmed osteoblast features of an active cell behavior able to fit cell to chemico-mechanical stimuli present at the bone/implant interface and suggests an effective implant/alveolar bone integration in vivo.

Role of the mitochondrial sodium/calcium exchanger in neuronal physiology and in the pathogenesis of neurological diseases

In neurons, as in other excitable cells, mitochondria extrude Ca(2+) ions from their matrix in exchange with cytosolic Na(+) ions. This exchange is mediated by a specific transporter located in the inner mitochondrial membrane, the mitochondrial Na(+)/Ca(2+) exchanger (NCX(mito)). The stoichiometry of NCX(mito)-operated Na(+)/Ca(2+) exchange has been the subject of a long controversy, but evidence of an electrogenic 3 Na(+)/1 Ca(2+) exchange is increasing. Although the molecular identity of NCX(mito) is still undetermined, data obtained in our laboratory suggest that besides the long-sought and as yet unfound mitochondrial-specific NCX, the three isoforms of plasmamembrane NCX can contribute to NCX(mito) in neurons and astrocytes. NCX(mito) has a role in controlling neuronal Ca(2+) homeostasis and neuronal bioenergetics. Indeed, by cycling the Ca(2+) ions captured by mitochondria back to the cytosol, NCX(mito) determines a shoulder in neuronal [Ca(2+)](c) responses to neurotransmitters and depolarizing stimuli which may then outlast stimulus duration. This persistent NCX(mito)-dependent Ca(2+) release has a role in post-tetanic potentiation, a form of short-term synaptic plasticity. By controlling [Ca(2+)](m) NCX(mito) regulates the activity of the Ca(2+)-sensitive enzymes pyruvate-, alpha-ketoglutarate- and isocitrate-dehydrogenases and affects the activity of the respiratory chain. Convincing experimental evidence suggests that supraphysiological activation of NCX(mito) contributes to neuronal cell death in the ischemic brain and, in epileptic neurons coping with seizure-induced ion overload, reduces the ability to reestablish normal ionic homeostasis. These data suggest that NCX(mito) could represent an important target for the development of new neurological drugs.

Up-regulation and increased activity of KV3.4 channels and their accessory subunit MinK-related peptide 2 induced by amyloid peptide are involved in apoptotic neuronal death

The aim of the present study was to investigate whether K(V)3.4 channel subunits are involved in neuronal death induced by neurotoxic beta-amyloid peptides (Abeta). In particular, to test this hypothesis, three main questions were addressed: 1) whether the Abeta peptide can up-regulate both the transcription/translation and activity of K(V)3.4 channel subunit and its accessory subunit, MinK-related peptide 2 (MIRP2); 2) whether the increase in K(V)3.4 expression and activity can be mediated by the nuclear factor-kappaB (NF-kappaB) family of transcriptional factors; and 3) whether the specific inhibition of K(V)3.4 channel subunit reverts the Abeta peptide-induced neurodegeneration in hippocampal neurons and nerve growth factor (NGF)-differentiated PC-12 cells. We found that Abeta(1-42) treatment induced an increase in K(V)3.4 and MIRP2 transcripts and proteins, detected by reverse transcription-polymerase chain reaction and Western blot analysis, respectively, in NGF-differentiated PC-12 cells and hippocampal neurons. Patch-clamp experiments performed in whole-cell configuration revealed that the Abeta peptide caused an increase in I(A) current amplitude carried by K(V)3.4 channel subunits, as revealed by their specific blockade with blood depressing substance-I (BDS-I) in both hippocampal neurons and NGF-differentiated PC-12 cells. The inhibition of NF-kappaB nuclear translocation with the cell membrane-permeable peptide SN-50 prevented the increase in K(V)3.4 protein and transcript expression. In addition, the SN-50 peptide was able to block Abeta(1-42)-induced increase in K(V)3.4 K(+) currents and to prevent cell death caused by Abeta(1-42) exposure. Finally, BDS-I produced a similar neuroprotective effect by inhibiting the increase in K(V)3.4 expression. As a whole, our data indicate that K(V)3.4 channels could be a novel target for Alzheimer's disease pharmacological therapy.

OPSI (overwhelming postsplenectomy infection) syndrome: a case report

Splenectomized patients are likely to suffer from severe infections, such as sepsis and meningitis. This syndrome is called overwhelming postsplenectomy infection (OPSI) in Europe and America. We present an adult case of OPSI syndrome, which occurred as respiratory insufficiency, and thrombocytopenia. The course is rapid, the clinical symptoms are serious, and the prognosis is very poor. Clinical examination showed cyanosis, mandibular hypertonia, psychomotor anxiety and purpura. Laboratory findings were thrombocytopenia, leukocytosis, hypoglycemia and altered coagulation parameters. A chest X-ray showed right pulmonary aspecific thickening. The autopsy findings occurred as Waterhouse-Friderichsen syndrome.

A novel mutation in KCNQ2 associated with BFNC, drug resistant epilepsy, and mental retardation

BACKGROUND

Benign familial neonatal convulsion (BFNC) is a rare autosomal dominant disorder caused by mutations in two genes, KCNQ2 and KCNQ3, encoding for potassium channel subunits underlying the M-current. This current limits neuronal hyperexcitability by causing spike-frequency adaptation.

METHODS

The authors describe a BFNC family with four affected members: two of them exhibit BFNC only while the other two, in addition to BFNC, present either with a severe epileptic encephalopathy or with focal seizures and mental retardation.

RESULTS

All affected members of this family carry a novel missense mutation in the KCNQ2 gene (K526N), disrupting the tri-dimensional conformation of a C-terminal region of the channel subunit involved in accessory protein binding. When heterologously expressed in CHO cells, potassium channels containing mutant subunits in homomeric or heteromeric configuration with wild-type KCNQ2 and KCNQ3 subunits exhibit an altered voltage-dependence of activation, without changes in intracellular trafficking and plasma membrane expression.

CONCLUSION

The KCNQ2 K526N mutation may affect M-channel function by disrupting the complex biochemical signaling involving KCNQ2 C-terminus. Genetic rather than acquired factors may be involved in the pathophysiology of the phenotypic variability of the neurologic symptoms associated with BFNC in the described family.

Granulocytic sarcoma (chloroma) in HIV patient: a report

Isolated chloromas (granulocytic sarcomas) are rare tumours. Chloromas are masses composed of immature granulocytic cells. Granulocytic sarcoma occurs primarily in patients with acute myelogenous leukaemia, but can also arise in patients with other myeloproliferative disorders. We present an adult case of chloroma in HIV patient, which occurred as sudden death. Skin examination of right thigh showed dyschromia. Longitudinal incision of muscle revealed a "dark green" infiltration. Pathology showed in muscle fragments a infiltrate of granulocytes. The histologic sections of the excised tumour confirmed the cytologic diagnosis of chloroma.

A novel KCNQ2 K+ channel mutation in benign neonatal convulsions and centrotemporal spikes

Patients with benign familial neonatal convulsions (BFNC) may develop various epilepsies or epilepsy-associated EEG traits. A heterozygous 1-base pair deletion (2043DeltaT) in the KCNQ2 gene encoding for K+ channel subunits was found in a patient with BFNC who showed centrotemporal spikes at age 3 years. Electrophysiologic studies showed that mutant K+ channel subunits failed to give rise to functional homomeric channels or exert dominant-negative effects when expressed with KCNQ2/KCNQ3 subunits.

[Intraoperative cholangiography during laparoscopic cholecystectomy: selective or routine?]

Since its presentation by Mirizzi in 1931, the role of intraoperative cholangiography (ICHO) has been controversial and has become an argument even more disputed with the introduction of laparoscopic cholecystectomy (VLC) in 1988. The Authors reviewed their experience to determine the most appropriate use of ICHO during VLC on the basis of a retrospective analysis of cases of selective ICHO. From December 1991 to January 2001, 597 patients, 552 elective procedure and 45 emergency procedure, were reviewed. Of 552 patients 62 presented with at least one diagnostic criterion for symptomatic gallstone disease and were treated by means of ERCP completed with endoscopic sphincterectomy (ES) when a stone of the common bile duct was found, while the remaining 490 patients underwent VLC; a total of 10 ICHO were performed, two of which in the ERCP group and 8 in the VLC group. The 45 patients treated in emergency underwent VLC; in 43 cases ICHO was performed. Of all patients, there were 2 cases of common bile duct injuries (0.33%) and in both cases ICHO was not performed. A cholangiogram added 27 min to the average duration of surgery. On the basis of both the literature and Authors' experience, it can be stated that the routine use of ICHO is not useful to reduce bile duct injuries, while it significantly increases the cost of the surgical procedure due to the increase of average operative time. The use of ICHO seems to be effective to demonstrate clinically unsuspected choledocholitiasis, although, at present, the real clinical advantage deriving from the detection of these stones is not clear. The Authors conclude that further prospective, randomized studies are necessary to assess the precise role of ICHO with regard to VLC.

Inhibition of depolarization-induced [3H]noradrenaline release from SH-SY5Y human neuroblastoma cells by some second-generation H(1) receptor antagonists through blockade of store-operated Ca(2+) channels (SOCs)

In the present study, the effect of the blockade of membrane calcium channels activated by intracellular Ca(2+) store depletion on basal and depolarization-induced [3H]norepinephrine ([3H]NE) release from SH-SY5Y human neuroblastoma cells was examined. The second-generation H(1) receptor blockers astemizole, terfenadine, and loratadine, as well as the first-generation compound hydroxyzine, inhibited [3H]NE release induced by high extracellular K(+) concentration ([K(+)](e)) depolarization in a concentration-dependent manner (the IC(50)s were 2.3, 1.7, 4.8, and 9.4 microM, respectively). In contrast, the more hydrophilic second-generation H(1) receptor blocker cetirizine was completely ineffective (0.1-30 microM). The inhibition of high [K(+)](e)-induced [3H]NE release by H(1) receptor blockers seems to be related to their ability to inhibit Ca(2+) channels activated by Ca(i)(2+) store depletion (SOCs). In fact, astemizole, terfenadine, loratadine, and hydroxyzine, but not cetirizine, displayed a dose-dependent inhibitory action on the increase in intracellular Ca(2+) concentrations ([Ca(2+)](i)) obtained with extracellular Ca(2+) reintroduction after Ca(i)(2+) store depletion with thapsigargin (1 microM), an inhibitor of the sarcoplasmic-endoplasmic reticulum calcium ATPase (SERCA) pump. The rank order of potency for SOC inhibition by these compounds closely correlated with their inhibitory properties on depolarization-induced [3H]NE release from SH-SY5Y human neuroblastoma cells. Nimodipine (1 microM) plus omega-conotoxin (100 nM) did not interfere with the present model for SOC activation. In addition, the inhibition of depolarization-induced [3H]NE release does not seem to be attributable to the blockade of the K(+) currents carried by the K(+) channels encoded by the human Ether-a-Gogo Related Gene (I(HERG)) by these antihistamines. In fact, whole-cell voltage-clamp experiments revealed that the IC(50) for astemizole-induced hERG blockade is about 300-fold lower than that for the inhibition of high K(+)-induced [3H]NE release. Furthermore, current-clamp experiments in SH-SY5Y cells showed that concentrations of astemizole (3 microM) which were effective in preventing depolarization-induced [3H]NE release were unable to interfere with the cell membrane potential under depolarizing conditions (100 mM [K(+)](e)), suggesting that hERG K(+) channels do not contribute to membrane potential control during exposure to elevated [K(+)](e). Collectively, the results of the present study suggest that, in SH-SY5Y human neuroblastoma cells, the inhibition of SOCs by some second-generation antihistamines can prevent depolarization-induced neurotransmitter release.

Advanced glycation end product levels in eye lenses, aorta, and tail tendon in transplanted diabetic inbred Lewis rats

BACKGROUND

Pancreatic islet transplantation in diabetes, by restoring euglycemia, should in time correct the abnormal accumulation of advanced glycation end products (AGEs) over target tissues, thus delaying the development of late diabetic complications.

METHODS

Homologous islet transplantation was performed in inbred Lewis rats 15 days (TA), 4 months (TB), and 8 months (TC) after streptozotocin diabetes. Group TA was studied for 12 months and groups TB and TC were studied for 4 months after transplantation. Normal (N) and diabetic (D) rats formed the control groups. Metabolic control in the transplant (T) groups was evaluated by oral glucose tolerance test. Blood glucose, glycated hemoglobin, and body weight were determined in all groups. AGE levels were determined by spectrofluorometry in eye lens proteins and by ELISA in aortic and tail tendon collagen.

RESULTS

T groups showed normal oral glucose tolerance tests and metabolic parameters. The latter were altered in all D groups (P<0.005 to P<0.0001 versus N and T groups). AGEs were increased in the D groups (P<0.05 to P<0.001) versus the N groups. AGEs in the TA and TB groups were not different from those of the N groups but were significantly reduced (P<0.05 to P<0.001) when compared with those of the D groups. In the TC group, eye lens AGEs were significantly elevated (P<0.001) or significantly reduced (P<0.01) when compared with those of the N or D groups, respectively. Aortic collagen AGEs were elevated (P<0.01) by comparison with those of the N groups and not statistically different from those of the D groups. Tail tendon collagen AGE levels lay between those of the N and D groups, without reaching a statistical significance.

CONCLUSIONS

These results indicate that primary and early secondary (groups TA and TB) but not late secondary (group TC) islet transplantations are capable of blocking or reducing an abnormal accumulation of AGEs, thus confirming the importance of preventive transplantation therapies.

Plasma proteins containing damaged L-isoaspartyl residues are increased in uremia: implications for mechanism

BACKGROUND

Several alterations of protein structure and function have been reported in uremia. Impairment of a transmethylation-dependent protein repair mechanism possibly related to a derangement in homocysteine metabolism is also present in this condition, causing erythrocyte membrane protein damage. Homocysteine may affect proteins via the accumulation of its parent compound S-adenosylhomocysteine (AdoHcy), a powerful in vivo methyltransferase inhibitor. However, since plasma homocysteine is mostly protein bound, a direct influence on protein structures cannot be ruled out. We measured the levels of L-isoaspartyl residues in plasma proteins of uremic patients on hemodialysis. These damaged residues are markers of molecular age, which accumulate when transmethylation-dependent protein repair is inhibited and/or protein instability is increased.

METHODS

L-isoaspartyl residues in plasma proteins were quantitated using human recombinant protein carboxyl methyl transferase (PCMT). Plasma concentrations of homocysteine metabolites were also measured under different experimental conditions in hemodialysis patients.

RESULTS

The concentration of damaged plasma proteins was increased almost twofold compared to control (controls 147.83 +/- 17.75, uremics 282.80 +/- 26.40 pmol of incorporated methyl groups/mg protein, P < 0.003). The major protein involved comigrated with serum albumin. Although hyperhomocysteinemia caused a redistribution of thiols bound to plasma proteins, this mechanism did not significantly contribute to the increase in isoaspartyl residues. The S-adenosylmethionine (AdoMet)/AdoHcy concentration ratio, an indicator of the flux of methyl group transfer, was altered. This ratio was partially corrected by folate treatment (0.385 +/- 0.046 vs. 0.682 +/- 0.115, P < 0.01), but protein L-isoaspartate content was not.

CONCLUSIONS

Plasma protein damage, as determined by protein L-isoaspartyl content, is increased in uremia. This alteration is to be ascribed to an increased protein structural instability, rather than the effect of hyperhomocysteinemia.

Homocysteine and transmethylations in uremia

Homocysteine is regarded as a cardiovascular risk factor in both the general population and chronic renal failure patients. Among the mechanisms for homocysteine toxicity, its interference with transmethylation reactions, through its precursor/derivative S-adenosylhomocysteine, plays a multifarious role. In uremia, inhibition of S-adenosylmethionine methyl transfer reactions has been reported by independent investigators, using multiple approaches. This has several possible consequences, which can ultimately affect the patient's relative state of health.

Retention in the endoplasmic reticulum as a mechanism of dominant-negative current suppression in human long QT syndrome

Mutations in the cardiac potassium channel HERG (KCNH2) cause chromosome 7-linked long QT syndrome (LQT2) characterized by a prolonged QT interval, recurrent syncope and sudden cardiac death. Most mutations in HERG exhibit "loss of function" phenotypes with defective channels either inserted into the plasma membrane or retained in the endoplasmic reticulum. "Loss of function" mutations reduce I(Kr), the cardiac delayed rectifier current encoded by HERG, due to haploinsufficiency or suppression of wild-type function by a dominant-negative mechanism. One explanation for dominant-negative current suppression is that mutant subunits render tetrameric channel complexes non-conducting on co-assembly. In the present paper we describe an alternative mechanism for this phenomenon. We show (1) that the dominant-negative HERG mutation A561V is retained in the endoplasmic reticulum and (2) that wild-type channels are tagged for retention in the ER by co-assembly with trafficking deficient A561V subunits. Thus, in HERG A561V dominant-negative suppression of wild-type function is the result of an acquired trafficking defect.

Inhibition of HERG1 K(+) channels by the novel second-generation antihistamine mizolastine

1. Ventricular arrhythmias are rare but life-threatening side effects of therapy with the second-generation H(1) receptor antagonists terfenadine and astemizole. Blockade of the K(+) channels encoded by the Human Ether-à-go-go-Related Gene 1 (HERG1) K(+) channels, which is the molecular basis of the cardiac repolarizing current I(Kr), by prolonging cardiac repolarization, has been recognized as the mechanism underlying the cardiac toxicity of these compounds. 2. In the present study, the potential blocking ability of the novel second-generation H(1) receptor antagonist mizolastine of the HERG1 K(+) channels heterologously expressed in Xenopus oocytes and in HEK 293 cells or constitutively present in SH-SY5Y human neuroblastoma cells has been examined and compared to that of astemizole. 3. Mizolastine blocked HERG1 K(+) channels expressed in Xenopus oocytes with an estimated IC(50) of 3.4 microM. Mizolastine blockade was characterized by a fast dissociation rate when compared to that of astemizole; when fitted to a monoexponential function, the time constants for drug dissociation from the K(+) channel were 72.4+/-11.9 s for 3 microM mizolastine, and 1361+/-306 s for 1 microM astemizole. 4. In human embryonic kidney 293 cells (HEK 293 cells) stably transfected with HERG1 cDNA, extracellular application of mizolastine exerted a dose-related inhibitory action on I(HERG1), with an IC(50) of 350+/-76 nM. Furthermore, mizolastine dose-dependently inhibited HERG1 K(+) channels constitutively expressed in SH-SY5Y human neuroblastoma clonal cells. 5. The results of the present study suggest that the novel second-generation H(1) receptor antagonist mizolastine, in concentrations higher than those achieved in vivo during standard therapy, is able to block in some degree both constitutively and heterologously expressed HERG1 K(+) channels, and confirm the heterogeneity of molecules belonging to this therapeutical class with respect to their HERG1-inhibitory action.

Do glia have heart? Expression and functional role for ether-a-go-go currents in hippocampal astrocytes

Potassium homeostasis plays an important role in the control of neuronal excitability, and diminished buffering of extracellular K results in neuronal Hyperexcitability and abnormal synchronization. Astrocytes are the cellular elements primarily involved in this process. Potassium uptake into astrocytes occurs, at least in part, through voltage-dependent channels, but the exact mechanisms involved are not fully understood. Although most glial recordings reveal expression of inward rectifier currents (K(IR)), it is not clear how spatial buffering consisting of accumulation and release of potassium may be mediated by exclusively inward potassium fluxes. We hypothesized that a combination of inward and outward rectifiers cooperate in the process of spatial buffering. Given the pharmacological properties of potassium homeostasis (sensitivity to Cs(+)), members of the ether-a-go-go (ERG) channel family widely expressed in the nervous system could underlie part of the process. We used electrophysiological recordings and pharmacological manipulations to demonstrate the expression of ERG-type currents in cultured and in situ hippocampal astrocytes. Specific ERG blockers (dofetilide and E 4031) inhibited hyperpolarization- and depolarization-activated glial currents, and ERG blockade impaired clearance of extracellular potassium with little direct effect on hippocampal neuron excitability. Immunocytochemical analysis revealed ERG protein mostly confined to astrocytes; ERG immunoreactivity was absent in presynaptic and postsynaptic elements, but pronounced in glia surrounding the synaptic cleft. Oligodendroglia did not reveal ERG immunoreactivity. Intense immunoreactivity was also found in perivascular astrocytic end feet at the blood-brain barrier. cDNA amplification showed that cortical astrocytes selectively express HERG1, but not HERG2-3 genes. This study provides insight into a possible physiological role of hippocampal ERG channels and links activation of ERG to control of potassium homeostasis.

Modulation of the K(+) channels encoded by the human ether-a-gogo-related gene-1 (hERG1) by nitric oxide

The inhibition of nitric oxide synthase by N-nitro-L-arginine methyl ester (0.03-3 mM) dose-dependently reduced nitric oxide (NO(*)) levels and enhanced the outward currents carried by human ether-a-gogo-related gene-1 (hERG1) K(+) channels expressed in Xenopus laevis oocytes, whereas the increase in NO(*) levels achieved by exposure to L-arginine (0.03-10 mM) inhibited these currents. Furthermore, four NO(*) donors belonging to such different chemical classes as sodium nitroprusside (1-1000 microM), 3-morpholino-sydnonimine (100-1000 microM), (Z)-1-[N-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1- ium-1, 2-diolate (NOC-18; 1-300 microM), and S-nitroso N-acetylpenicillamine (1-300 microM) dose-dependently inhibited hERG1 outward K(+) currents. By contrast, the NO(*) donor NOC-18 (0.3 mM) did not affect other cloned K(+) channels such as rat neuroblastoma-glioma K(+) channel 2, rat delayed rectifier K(+) channel 1, bovine ether-a-gogo gene, rat ether-a-gogo-related gene-2, and rat ether-a-gogo-related gene-3. The inhibitory effect of NO(*) donors on hERG1 K(+) channels was prevented by the NO(*) scavengers 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide and hemoglobin. The membrane permeable analog of cGMP, 8-bromo-cGMP (1 mM), failed to reproduce the inhibitory action of NO(*) donors on hERG1 outward currents; furthermore, the specific inhibitor of the NO(*)-dependent guanylyl cyclase, 1H-[1,2,4]oxadiazolo[4, 3-a]quinoxalin-1-one (50 microM), neither interfered with outward hERG1 K(+) currents nor prevented their inhibition by 0.3 mM NOC-18. Both L-arginine (10 mM) and NOC-18 (0.3 mM) counteracted the stimulatory effect on hERG1 outward currents induced by the radical oxygen species-generating system FeSO(4) (25 microM)/ascorbic acid (50 microM; Fe/Asc). Finally, L-arginine (10 mM) and NOC-18 (0.3 mM) inhibited both basal and Fe/Asc (0.1 mM/0.2 mM)-stimulated lipid peroxidation in X. laevis oocytes. Collectively, the present results suggest that NO(*), both endogenously produced and pharmacologically delivered, may exert in a cGMP-independent way an inhibitory effect on hERG1 outward K(+) currents via an interaction with radical oxygen species either generated under resting conditions or triggered by Fe/Asc.

Cardiac ion channels and antihistamines: possible mechanisms of cardiotoxicity

Despite the enormous success of second generation antihistamines, in the mid-1980s, about 10 years after their introduction in the market, several reports appeared in the literature indicating the rare occurrence of a form of polymorphic ventricular dysrhythmia, the 'torsade de pointes', after the administration of astemizole or terfenadine. This cardiac side-effect has been interpreted as a consequence of the interference of these drugs with cardiac K+ channels involved in action potential repolarization, and in particular with the IKr component of the cardiac repolarizing current. As the K+ channels encoded by the human ether-a-gogo-related gene (HERG) seem to represent the molecular basis of IKr, this cardiac K+ channel was soon recognized as a primary target for second generation antihistamine-induced proarrhythmic effects. In fact, both terfenadine and astemizole have been shown to block HERG K+ channels in a concentration range similar to that found in the plasma of subjects with cardiotoxic manifestations. However, no correlation can be found between the ability to prolong the cardiac action potential duration and the H1-antagonistic activity by several antihistamines, suggesting that HERG blockade and cardiotoxic potential are not class properties of second generation antihistamines. In fact, other molecules such as cetirizine, loratadine, acrivastine, and fexofenadine seem to lack both cardiotoxic potential and HERG-blocking ability at therapeutically relevant concentrations. The marked heterogeneity displayed by second generation antihistamines in their ability to prolong the cardiac action potential duration and to block HERG K+ channels might be of considerable therapeutical significance for those patients at risk of developing cardiac dysrhythmias and in need of therapy with H1-receptor blockers; it also emphasizes the importance of an evaluation of the possible blockade of HERG K+ channels during the early developmental phases of novel compounds belonging to this therapeutical class.

Homocysteine and chronic renal failure

Homocysteine, a sulfur amino acid, is an important methionine derivative, which has been implicated in the pathogenesis of atherothrombosis. Although only observational, epidemiological studies are available at present, the evidence of an association between hyperhomocysteinemia and increased cardiovascular risk is quite strong and this is confirmed also in a population of chronic renal failure patients. From a biochemical standpoint at least three mechanisms have been summoned so far in order to explain homocysteine toxicity including: oxidation, hypomethylation, and acylation. Proteins are believed to play a crucial role as homocysteine molecular targets. Interference with the functions of several of such macromolecules has been so far described being mediated by any of the above mechanisms. Vitamins may positively influence homocysteine metabolism, thus facilitating the metabolic clearance of this compound. Therefore they are presently considered as potential means for reducing plasma levels of this amino acid and preventing vascular occlusions in hyperhomocysteinemic patients. These compounds, with special regard to folate, are eligible for interventional clinical trials, from which the definitive answer on the role of homocysteine in atherothrombosis is expected.

Homocysteine, a new cardiovascular risk factor, is also a powerful uremic toxin

Homocystinuria, an inherited disease in which plasma levels of homocysteine are high, was discovered in the sixties and it soon became clear that the affected patients had striking features of generalized atherosclerosis. The most common causes of death were arterial and venous thrombosis, stroke, or myocardial infarction. Observations in this human model of hyperhomocysteinemia led to studies in the general population whose findings suggest - though not conclusively- that homocysteine is a cardiovascular risk factor. The same is true for patients with chronic renal failure who almost always have moderate to severe high blood homocysteine levels. Homocysteine accumulates in relation to the concentration of its precursor, S-adenosylhomocysteine, a powerful competitive transmethylation inhibitor. Inhibition of a methyltransferase required to repair damaged proteins has actually been detected in uremic patients' red blood cells. However, in view of the multiple, widespread metabolic roles of S-adenosylmethionine-dependent methyltransferases, in many organs and tissues including the vascular endothelium, hypomethylation is currently interpreted as one of homocysteine's most important mechanisms of action. Various biological compounds, including small molecules and nucleic acids, as well as proteins, which are involved in the pathophysiology of thrombosis and atherosclerosis, are all potential targets of hypomethylation. Epidemiological studies and experimental models tend to confirm that homocysteine is both a cardiovascular risk factor and a uremic toxin, acting through different mechanisms.

Homocysteine, a new crucial element in the pathogenesis of uremic cardiovascular complications

Most large observational studies available today establish that moderate hyperhomocysteinemia, either genetically or nutritionally determined, is an independent risk factor for myocardial infarction, stroke, and thromboembolic disease. This is also true for chronic renal failure patients, who exhibit a high prevalence of hyperhomocysteinemia (85-100%), which reaches high plasma concentrations (20-40 microM, while control values range between 8 and 12 microM). After a renal transplant, homocysteine levels decrease, but tend to be higher than normal. The cause of hyperhomocysteinemia in renal failure is still obscure, since recent data have questioned the previous notion that a net homocysteine renal extraction and/or excretion take place in man. No matter the cause of its increase, the sulfur amino acid homocysteine is thought to induce an increment in cardiovascular risk through three basic biochemical mechanisms: (1) homocysteine oxidation, with H2O2 generation; (2) hypomethylation through S-adenosylhomocysteine accumulation, and (3) protein acylation by homocysteine thiolactone. The final result is membrane protein damage, endothelial damage, and endothelial cell growth inhibition, among other effects. Hyperhomocysteinemia, in general, is susceptible of therapeutic intervention with the vitamins involved in its metabolism. Depending on the cause, vitamin B6, vitamin B12, betaine, and/or folic acid can be effectively utilized. Chronic renal failure patients benefit from folic acid in high dosage: 1-2 mg are usually not effective ('relative folate resistance'), while 5-15 mg reduce homocysteine levels to a 'normative' range (<15 microM) in a substantial group of patients. Good results are also obtained in transplant patients, best with a combination of folic and vitamin B6. The results of the interventional trials focusing on the possible reduction in cardiovascular risk after homocysteine-lowering therapy, both in the general population and in end-stage renal disease, are expected soon, as well as the genetic and biochemical studies in suitable models, with the aim to clarify the cause-effect link suggested by the numerous observational and basic science studies.

Reduction of advanced glycation end-product (AGE) levels in nervous tissue proteins of diabetic Lewis rats following islet transplants is related to different durations of poor metabolic control

Advanced glycation end-products (AGEs) are irreversible compounds which, by abnormally accumulating over proteins as a consequence of diabetic hyperglycaemia, can damage tissues and thus contribute to the pathogenesis of diabetic complications. This study was performed to evaluate whether restoration of euglycaemia by islet transplantation modifies AGE accumulation in central and peripheral nervous tissue proteins and, as a comparison, in proteins from a non-nervous tissue. Two groups of streptozotocin diabetic inbred Lewis rats with 4 (T1) or 8 (T2) months disease duration were grafted into the liver via the portal vein with 1200-1500 islets freshly isolated from normal Lewis rats. Transplanted rats, age-matched control and diabetic rats studied in parallel, were followed for a further 4-month period. At study conclusion, glycaemia, glycated haemoglobin and body weight were measured in all animals, and an oral glucose tolerance test (OGTT) performed in transplanted rats. AGE levels in cerebral cortex, spinal cord, sciatic nerve proteins and tail tendon collagen were measured by enzyme-linked immunosorbent assay (ELISA). Transplanted animal OGTTs were within normal limits, as were glycaemia and glycated haemoglobin. Diabetic animal AGEs were significantly higher than those of control animals. Protein AGE values were reduced in many transplanted animals compared to diabetic animals, reaching statistical significance in spinal cord (P < 0.05), sciatic nerve (P < 0.02) and tail tendon collagen (P < 0.05) of T1 animals. Thus, return to euglycaemia following islet transplantation after 4 months of diabetes with poor metabolic control reduces AGE accumulation rate in the protein fractions of the mixed and purely peripheral nervous tissues (spinal cord and sciatic nerve, respectively). However, after a double duration of bad metabolic control, a statistically significant AGE reduction has not been achieved in any of the tissues, suggesting the importance of an early therapeutic intervention to prevent the possibly pathological accumulation of AGEs in nervous and other proteins.

Molecular basis for the lack of HERG K+ channel block-related cardiotoxicity by the H1 receptor blocker cetirizine compared with other second-generation antihistamines

In the current study, the potential blocking ability of K+ channels encoded by the human ether-a-go-go related gene (HERG) by the piperazine H1 receptor antagonist cetirizine has been examined and compared with that of other second-generation antihistamines (astemizole, terfenadine, and loratadine). Cetirizine was completely devoid of any inhibitory action on HERG K+ channels heterologously expressed in Xenopus laevis oocytes in concentrations up to 30 microM. On the other hand, terfenadine and astemizole effectively blocked HERG K+ channels with nanomolar affinities (the estimated IC50 values were 330 and 480 nM, respectively), whereas loratadine was approximately 300-fold less potent (IC50 approximately 100 microM). In addition, in contrast to terfenadine, cetirizine did not show use-dependent blockade. In SH-SY5Y cells, a human neuroblastoma clone that constitutively expresses K+ currents carried by HERG channels (IHERG), as well as in human embryonic kidney 293 cells stably transfected with HERG cDNA, extracellular perfusion with 3 microM cetirizine did not exert any inhibitory action on IHERG. Astemizole (3 microM), on the other hand, was highly effective. Terfenadine (3 microM) caused a marked (approximately 80%) inhibition of IHERG in SH-SY5Y cells, whereas loratadine, at the same concentration, caused a 40% blockade. Furthermore, the application of cetirizine (3 microM) on the intracellular side of the membrane of HERG-transfected human embryonic kidney 293 cells did not affect IHERG, whereas the same intracellular concentration of astemizole caused a complete block. The results of the current study suggest that second-generation antihistamines display marked differences in their ability to block HERG K+ channels. Cetirizine in particular, which possesses more polar and smaller substituent groups attached to the tertiary amine compared with other antihistamines, lacks HERG-blocking properties, possibly explaining the absence of torsade de pointes ventricular arrhythmias associated with its therapeutical use.

Human ether-a-gogo related gene (HERG) K+ channels as pharmacological targets: present and future implications

Electrophysiological and molecular biology techniques have widely expanded our knowledge of the diverse functions where K+ channels are implicated as potential and proven pharmacological targets. The aim of the present commentary is to review the recent progress in the understanding of the functional role of the K+ channels encoded by the human ether-a-gogo related gene (HERG), with particular emphasis on their direct pharmacological modulation by drugs, or on their regulation by pharmacologically relevant phenomena. About 3 years have passed since the cloning, expression, and description of the pathophysiological role of HERG K+ channels in human cardiac repolarization. Despite this short lapse of time, these K+ channels have already gained considerable attention as pharmacological targets. In fact, interference with HERG K+ channels seems to be the main mechanism explaining both the therapeutic actions of the class III antiarrhythmics and the potential cardiotoxicity of second-generation H1 receptor antagonists such as terfenadine and astemizole, as well as of psychotropic drugs such as some antidepressants and neuroleptics. It seems possible to anticipate that the main tasks for future investigation will be, on the one side, the better understanding of the intimate mechanism of action of HERG K+ channel-blocking drugs in order to elucidate the conditions regulating the delicate balance between antiarrhythmic and proarrhythmic potential and, on the other, to unravel the pathophysiological role of this K+ channel in the function of the brain and of other excitable tissues.

Levels of advanced glycosylation end-products (AGE) in sera of pregnant diabetic women: comparison between type 1, type 2 and gestational diabetes mellitus

The chronic hyperglycemia can lead to an increase of the advanced glycosylation end-products (AGE) levels on proteins and macromolecules. Abnormal levels of AGE in several tissues has been associated with the pathogenesis of late diabetic complications. In diabetic pregnant women, high AGE levels might influence the delicate maternal-fetal balance and therefore alter the pregnancy outcome. In this preliminary study, we have measured the AGE in sera of 44 diabetic women in two trimester. Sixteen sera from non diabetic pregnant women have been used as controls. The AGE have been analyzed by means of an ELISA method with an antiserum anti-RNAse-AGE, produced in the Laboratory of Clinical Biochemistry of the Istituto Superiore di Sanità. Diabetic patients type 1 and type 2, in good metabolic control, showed normal AGE levels at both trimester. Patients with gestational diabetes showed significantly high serum AGE levels (p < 0.05). A more extended study will give better insight on the association between AGE levels and a physiopathology of diabetic pregnancy.

The gene encoding a cationic amino acid transporter (SLC7A4) maps to the region deleted in the velocardiofacial syndrome

By screening an expressed sequence tag database, we identified a novel human gene, SLC7A4, encoding a solute carrier family 7 [cationic amino acid (CAA) CAT-4 transporter, y+ system] member 4. The SLC7A4 cDNA is 2325 nt long and includes 78, 1911, and 336 nt in the 5' noncoding, coding, and 3'-noncoding regions, respectively. SLC7A4 displays high homology with SLC7A1 and SLC7A2, two previously known CAA transporters. By chromosomal in situ hybridization and YAC identification, SLC7A4 was mapped to 22q11.2, the commonly deleted region of the velocardiofacial syndrome (VCFS, Shprintzen syndrome). In a patient affected by VCFS, deletion of SLC7A4 was demonstrated by chromosomal FISH. By Northern analysis, an abundant transcript was detected in brain, testis, and placenta. Microinjection of SLC7A4 mRNA into Xenopus laevis oocytes demonstrates a significant stimulation of CAA transport.

Biliary atresia-polysplenia syndrome: surgical and clinical relevance in liver transplantation

OBJECTIVE

To review a single center's 10-year experience with liver transplantation (LTx) for the biliary atresia-polysplenia syndrome (BA-PS) and to define surgical and clinical guidelines for its management.

SUMMARY BACKGROUND DATA

BA is the most common indication for pediatric liver transplantation (LTx) and is associated with PS in 12% of cases. Only a few studies of LTx for BA-PS have been reported, and the optimal management of BA-PS patients undergoing LTx has yet to be determined.

METHODS

From July 1985 to September 1995, 166 liver transplants were performed in 130 patients with BA and were included in the study. The malformations most commonly associated with BA-PS, surgical techniques used to overcome these anomalies, and surgical pitfalls that could have contributed to the outcome were characterized. Actuarial 10-year patient and graft survival for patients undergoing LTx for BA-PS were calculated and compared to those with isolated BA.

RESULTS

Ten patients (7.8%) with BA had associated PS. An additional patient with PS without BA was included in the study. The diagnosis of PS was unknown before the transplantation in 72% of cases. Thirteen liver transplants were performed in these 11 patients. Modifications of the usual surgical technique were used to overcome the complex anatomy encountered. There was no association between the type of anomaly and the outcome, nor were there any significant differences in patient survival (72% vs. 73.5%, p = 0.79) or graft survival (56.4% vs. 54.6%, p = 0.54).

CONCLUSIONS

The association of BA with various anomalies should be considered a spectrum that may vary widely from patient to patient. The finding of two or more of these malformations in a patient awaiting transplantation should lead the surgeon to look systematically for other associated anomalies. With some special surgical considerations, the outcome in BA-PS patients should not differ from those with isolated BA.

herg encodes a K+ current highly conserved in tumors of different histogenesis: a selective advantage for cancer cells?

The human ether-a-go-go-related gene (herg) encodes a K+ current (IHERG) that plays a fundamental role in heart excitability by regulating the action potential repolarization (IKr); mutations of this gene are responsible for the chromosome 7-linked long QT syndrome (LQT2). In this report, we show that in a variety (n = 17) of tumor cell lines of different species (human and murine) and distinct histogenesis (neuroblastoma, rhabdomyosarcoma, adenocarcinoma, lung microcytoma, pituitary tumors, insulinoma beta-cells, and monoblastic leukemia), a novel K+ inward-rectifier current (IIR), which is biophysically and pharmacologically similar to IHERG, can be recorded with the patch-clamp technique. Northern blot experiments with a human herg cDNA probe revealed that both in human and murine clones the very high expression of herg transcripts can be quantified in at least three clearly identifiable bands, suggesting an alternative splicing of HERG mRNA. Moreover, we cloned a cDNA encoding for IIR from the SH-SY5Y human neuroblastoma. The sequence of this cDNA result was practically identical to that already reported for herg, indicating a high conservation of this gene in tumors. Consistently, the expression of this clone in Xenopus oocytes showed that the encoded K+ channel had substantially all of the biophysical and pharmacological properties of the native IIR described for tumor cells. In addition, in the tumor clones studied, IIR governs the resting potential, whereas it could not be detected either by the patch clamp or the Northern blot techniques in cells obtained from primary cell cultures of parental tissues (sensory neurons and myotubes), whose resting potential is controlled by the classical K+ anomalous rectifier current. This current substitution had a profound impact on the resting potential, which was markedly depolarized in tumors as compared with normal cells. These results suggest that IIR is normally only expressed during the early stages of cell differentiation frozen by neoplastic transformation, playing an important pathophysiological role in the regulatory mechanisms of neoplastic cell survival. In fact, because of its biophysical features, IIR, besides keeping the resting potential within the depolarized values required for unlimited tumor growth, could also appear suitable to afford a selective advantage in an ischemic environment.

Magnetic resonance imaging in evaluation of the common bile duct

BACKGROUND

The ideal method for evaluation of the common bile duct (CBD) before or during cholecystectomy remains controversial. Magnetic resonance cholangiography (MRC) is a new, promising technique. A prospective evaluation is reported.

METHOD

Sixty-one patients (45 women) were studied by MRC. There were 29 patients with symptomatic gallstone disease and without clinical, biochemical or ultrasonographic evidence of CBD stones (group 1); 28 of them also underwent intraoperative cholangiography (IOC). In addition, there were 21 patients with symptomatic gallstone disease, with mild biochemical and ultrasonographic signs of CBD involvement (group 2), of whom 19 underwent IOC, and 11 patients with symptomatic CBD stones (group 3), nine of whom had preoperative endoscopic retrograde cholangiopancreatography (ERCP) following MRC.

RESULTS

MRC showed that no patient in group 1 and three patients in group 2 had CBD stones. Three patients (one in group 1, two in group 2) did not undergo IOC because of technical or clinical problems. In group 3, ERCP confirmed the results of MRC in nine patients. Two patients underwent open surgery because of ultrasonographic, MRC and radiographic signs of pancreatic malignancy.

CONCLUSION

MRC could replace IOC and ERCP for identification of asymptomatic CBD stones. In symptomatic patients MRC combined with other non-invasive imaging techniques can direct the surgeon to appropriate management.

Regulation of the human ether-a-gogo related gene (HERG) K+ channels by reactive oxygen species

Human ether-a-gogo related gene (HERG) K+ channels are key elements in the control of cell excitability in both the cardiovascular and the central nervous systems. For this reason, the possible modulation by reactive oxygen species (ROS) of HERG and other cloned K+ channels expressed in Xenopus oocytes has been explored in the present study. Exposure of Xenopus oocytes to an extracellular solution containing FeSO4 (25-100 microM) and ascorbic acid (50-200 microM) (Fe/Asc) increased both malondialdehyde content and 2',7'-dichlorofluorescin fluorescence, two indexes of ROS production. Oocyte perfusion with Fe/Asc caused a 50% increase of the outward K+ currents carried by HERG channels, whereas inward currents were not modified. This ROS-induced increase in HERG outward K+ currents was due to a depolarizing shift of the voltage-dependence of channel inactivation, with no change in channel activation. No effect of Fe/Asc was observed on the expressed K+ currents carried by other K+ channels such as bEAG, rDRK1, and mIRK1. Fe/Asc-induced stimulation of HERG outward currents was completely prevented by perfusion of the oocytes with a ROS scavenger mixture (containing 1,000 units/ml catalase, 200 ng/ml superoxide dismutase, and 2 mM mannitol). Furthermore, the scavenger mixture also was able to reduce HERG outward currents in resting conditions by 30%, an effect mimicked by catalase alone. In conclusion, the present results seem to suggest that changes in ROS production can specifically influence K+ currents carried by the HERG channels.

10-year experience of total thyroidectomy with special reference to 85 thyroid cancers in one Italian centre

The ideal surgical approach for differentiated thyroid carcinomas (DTC) is a matter for debate. Total (TT) or near total (NT) thyroidectomy on one side, and lobectomy (LL) or lobo-isthmusectomy (LI) on the other side are the options. Extended (TT, NT) resections are preferable for several reasons, and LL or LI are preferred by some groups. Our 10-year experience indicates that the post-operative complications percentage may be low enough to make TT the preferred surgical option.

Experience with enteric conversion after pancreatic transplantation with bladder drainage

BACKGROUND

Bladder drainage by the duodenal segment technique is currently the preferred method of handling the exocrine secretions after vascularized pancreatic transplantation. Despite improving results, however, the management of metabolic and urologic complications associated with bladder drainage remains problematic.

STUDY DESIGN

A retrospective survey was performed of a consecutive case series of 196 pancreatic transplantations in 186 patients with diabetes over an 80-month period. All patients underwent whole organ pancreatic transplantation with bladder drainage by the duodenal segment technique.

RESULTS

A total of 25 conversions (13 percent) from bladder drainage to enteric drainage were performed in 24 patients (24 side-to-side duodenoenterostomies, one Roux-en-Y limb duodenoenterostomy). The mean time of enteric conversion after pancreatic transplantation was 22 +/- 18 months (range, 1 to 72 months). All but two of the enteric conversions were performed at least 6 months after pancreatic transplantation. Indications for enteric conversion included dehydration with intractable metabolic acidosis (n = 18; 9 percent), urologic complications (n = 5; 3 percent), or problems with the duodenal segment (n = 2; 1 percent). The mean length of hospitalization for enteric conversion was 12 +/- 7 days (range, 6 to 30 days). All patients experienced improvement in their symptoms after enteric conversion. Anastomotic leaks developed postoperatively in five patients; two were managed operatively and three were managed nonoperatively. Oral bicarbonate supplementation was eliminated in all but one patient after enteric conversion. Patient survival is 100 percent and pancreatic graft survival (insulin independence) is 96 percent after a mean follow-up of 22 months after enteric conversion.

CONCLUSIONS

Enteric conversion after pancreatic transplantation with bladder drainage is a safe and effective therapy for refractory problems related to the duodenal segment, altered physiologic function, or urologic complications and should be considered after 6 months for patients with persistent side effects.

[Clinical manifestations in benign breast diseases. The surgeon's role in the evaluation of signs and diagnostic work-up]

From January 1988 through December 1995, 1022 patients having a breast disease have been operated on in our center. Of them 342 had a breast malignancies whereas 680 beared a benign breast disease. Benign breast pathology presents to the physician two main problems, they are: i) the need to rule out a breast cancer, which often may be simulated by special clinical presentation ii) the need to determine if eventually such a benign lesion can degenerate into a malignancy. We conclude according to our experience and following several authors that although a very careful diagnostic evaluation must be performed for every breast lesion, only few benign lesions arising with particular patterns can change into a breast cancer.

Protection by coenzyme Q10 of tissue reperfusion injury during abdominal aortic cross-clamping

PURPOSE

To evaluate the effect of coenzyme Q10 in reducing the skeletal muscle reperfusion injury following clamping and declamping the abdominal aorta.

METHODS

30 patients undergoing elective vascular surgery for abdominal aortic aneurysm or obstructive aorto-iliac disease were randomly divided into two groups: patients in group I were treated with coenzyme Q10 (150 mg/day) for seven days before operation, and those in group II received a placebo. We studied the hemodynamic profile in each patient during clamping and declamping of the abdominal aorta. The plasma concentrations of thiobarbituric acid reactive substances (malondialdhehyde), conjugated dienes, creatine kinase and lactate dehydrogenase were measured in samples from both arterial and inferior vena cava sites. Serial sampling was performed after induction of anesthesia, 5 and 30 minutes after abdominal aortic cross clamping, 5 and 30 minutes after aortic cross-clamp removal.

RESULTS

The concentrations of malondialdehyde, conjugated dienes, creatine kinase and lactate dehydrogenase in patients who received CoQ10 were significantly lower than in the placebo group. Decrease of plasma malondialdehyde concentrations correlated positively (p < 0.01) with decrease of both creatine kinase and lactate dehydrogenase release in samples from the inferior vena cava. The hemodynamic profile during clamping and declamping the abdominal aorta was similar in both groups.

CONCLUSIONS

Our findings suggest that pre-treatment with coenzyme Q10 may play a protective role during routine vascular procedures requiring abdominal aortic cross clamping by attenuating the degree of peroxidative damage.

Octopus vulgaris (Mollusca, Cephalopoda) as a model in behavioral pharmacology: a test of handling effects

Despite the great interest of Cephalopods in learning studies, behavioral pharmacological experiments using these animals are scanty. The purpose of this study was to find an appropriate method of injection of substances for studying their effects on the behavior of octopuses. We injected into the branchial heart a known volume of seawater to test the effect of cold anaesthesia and of different types of manipulation on the predatory performance of Octopus vulgaris. An injection procedure that is simple, reliable, and does not require anaesthesia is proposed. The article also addresses ethical and manipulation requirements of modern behavioral pharmacology.

Experience with protocol biopsies after solitary pancreas transplantation

The early detection of allograft rejection remains elusive after solitary pancreas transplantation (PTX). We have previously described a modified technique of cystoscopic transduodenal PTX biopsy using the Biopty gun under ultrasound guidance. During the last 2 years, we performed 24 solitary PTXs with prospective protocol biopsy monitoring as well as biopsies performed whenever clinically indicated. The study group included 17 pancreas transplants alone, 6 sequential pancreas after kidney transplants, and 1 sequential pancreas after liver transplant. Five patients received pancreas retransplants. A total of 92 cystoscopically directed core PTX biopsies were performed, including 50 protocol biopsies (mean 2.1 per patient). Protocol biopsies were performed at 1 month (19), 2 months (3), 3 months (20), 6 months (7), and 12 months (1) after PTX. Adequate PTX tissue for histopathologic examination was obtained in 49 cases (98%). Biopsy findings included no rejection (34), mild rejection (13), pancreatitis (1), and cytomegalovirus infection (1). Overall, 15 of the 49 evaluable biopsies (31%) had significant histopathologic findings. All but 1 of the cases of mild rejection were treated with bolus steroids. Eight of these patients subsequently developed recurrent biopsy-proven rejection within 2 months; 5 grafts were subsequently lost to rejection between 3 and 13 months after PTX. Three biopsy complications occurred: 1 hematoma, 1 pancreatitis, and 1 ileus. Patient survival is 96% and PTX graft survival (complete insulin independence) is 75% after a mean follow-up of 15 months. In the remaining 42 clinically indicated biopsies, 3 were insufficient, 8 showed no rejection, and 31 (79%) had rejection. In half of these cases, the rejection was graded as moderate to severe. In conclusion, prospective monitoring with protocol PTX biopsies may result in the earlier detection of allograft rejection and have a direct effect on improving results after solitary PTX.