Altered oxidative stress profile in the cortex of mice fed an enriched branched-chain amino acids diet: possible link with amyotrophic lateral sclerosis?

Branched-chain amino acids (BCAAs), valine, isoleucine, and leucine, are widely used among athletes as dietary integrators. Although the occurrence of untoward effects of BCCA supplementation, with particular regard to neurological disturbances, cannot be excluded, no specific studies have been performed so far. The aim of this work was to evaluate the effects of a diet enriched in BCAAs on the expression of oxidative stress pathway genes in the brain of C57Bl/6J mice. Animals were fed a standard or a BCAA diet for 95 days starting from postnatal day 21 until sacrifice. BCAA treatment, at doses comparable to human usage, significantly down-regulated the expression of some antioxidant genes, while up-regulating the expression of some oxygen transporters. In conclusion, it appears that BCAAs administered by diet could alter some specific oxidative stress pathways in the brain. Caution should thus be exercised in the widespread use of BCAAs as dietary integrators in sports practice.

Posterior parahepatic cyst as an incidental finding--review of 40 cases.

AIM: To describe the characteristic imaging features of the incidental, isolated posterior parahepatic cyst. METHODS: Out of 150 patients previously identified on computed tomography (CT) to have an incidental, isolated posterior parahepatic cyst, 40 patients had lesions that were large enough to be assessed for enhancement on CT and/or magnetic resonance imaging (MRI) and had at least 1 year of imaging follow-up. All available CT, MRI, and 2- [(18)F]-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography (PET) examinations for these 40 patients were reviewed, and the lesions were assessed for size, attenuation, and location relative to the spine and right kidney. RESULTS: For the 40 patients reviewed, all parahepatic lesions were shown to be cysts by absence of identifiable enhancement on CT or MRI. Cysts ranged in size from 3mm to 2.5cm. Hounsfield unit (HU) measurements ranged from 12HU to 83HU. In the transverse plane, all cysts were located lateral to the lateral margin of the right kidney. In the craniocaudal dimension, all cysts were at or above the level of the right kidney, and all were located between the T11-12 and L1-2 vertebral levels. All cysts were stable on follow-up imaging with a mean duration of follow-up of 41 months. CONCLUSION: Isolated, indolent posterior parahepatic cysts have a characteristic appearance and location and demonstrate benign behaviour with stability on follow-up imaging. These cysts should be considered in the differential diagnosis for isolated parahepatic lesions, and the imaging features described here aid in the distinction of these cysts from other entities such as metastatic disease.

Pain relief and motor function during continuous interscalene analgesia after open shoulder surgery: a prospective, randomized, double-blind comparison between levobupivacaine 0.25%, and ropivacaine 0.25% or 0.4%.

BACKGROUND AND OBJECTIVES: To compare pain relief and motor impairment of 0.25% levobupivacaine with either an equivalent (0.25%) or equipotent (0.4%) concentration of ropivacaine for continuous interscalene block after open shoulder surgery. METHODS: Seventy-two adult patients scheduled for elective major shoulder surgery received an interscalene injection of mepivacaine 1.5% 30 mL followed by 24 h patient-controlled interscalene analgesia (basal infusion rate: 5 mL h-1; incremental bolus: 2 mL; lockout period: 10 min; maximum boluses per hour: 4) with either 0.25% levobupivacaine (n = 24), 0.25% ropivacaine (n = 24) or 0.4% ropivacaine (n = 24). A blinded observer recorded the evolution of pain relief and recovery of motor block during the first 24 h. Motor function was assessed as the maximum pressure developed while squeezing a sphygmomanometer cuff with the blocked hand. The reduction from preoperative values was considered as an index of motor impairment. RESULTS: No differences were reported among the three groups in the quality of postoperative analgesia. The number of incremental patient-controlled interscalene analgesia doses, total volume of local anaesthetic infused during the 24-h patient-controlled interscalene analgesia, and number of rescue ketoprofen analgesia were higher in the ropivacaine 0.25% group than in the other two groups (P = 0.0005). The hand strength recovered to >or=90% of baseline values within the first 24 h of infusion in all groups, without differences among the three groups. CONCLUSION: When providing patient-controlled interscalene analgesia after open shoulder surgery 0.25% levobupivacaine and 0.4% ropivacaine performed equally in terms of pain relief, motor block and number of patient-controlled boluses required, while patients receiving 0.25% ropivacaine needed significantly more boluses and rescue analgesia to control their pain.

Psychological and adjustment problems due to acquired brain lesions in childhood: a comparison between post-traumatic patients and brain tumour survivors.

OBJECTIVE: To define and differentiate psychological and adjustment problems due to brain injury or brain tumour in children and adolescents. METHODS: Two groups of patients with acquired brain lesions (24 post-traumatic patients and 22 brain tumour survivors), ranging in age between 8-15 years, received a psychological evaluation, including the Child Behaviour Checklist for Ages 4-18 (CBCL) and the Vineland Behaviour Adaptive Scales (VABS). RESULTS: Both groups showed psychological and social adjustment problems. Post-traumatic patients were more impaired than brain tumour survivors. Social adjustment problems were associated to externalizing problems in post-traumatic patients and internalizing problems in brain tumour surviving patients. CONCLUSIONS: These differences in psychological and behavioural disorders between the two groups must necessarily be considered when developing psychological treatment, rehabilitation plan and social re-entry.

Changes in hemodynamics during isoflurane and propofol anesthesia: a comparison study.

OBJECTIVES: Volatile anesthetics are thought to impair cerebral autoregulation more than i.v. anesthetics. However, few comparative studies have been carried out in humans. The aim of our study was to evaluate the differences in cerebral hemodynamic changes after introduction of isoflurane (a volatile anesthetic) and propofol (an i.v. anesthetic). METHODS: Eighteen consecutive patients submitted to laparoscopic cholecystectomy were selected. After the induction, anesthesia was maintained by isoflurane (one minimum alveolar anesthetic concentration) during the first part of the surgical operation, and then by propofol (5 mg/kg/hour i.v.). Ventilation was adjusted to maintain a constant end-tidal CO(2). Middle artery flow velocity was assessed by means of transcranial Doppler ultrasonography. Arterial blood pressure, heart rate (HR), capnometry, pulse oxymetry, inspired fraction of O(2), and body temperature, were monitored. RESULTS: Cerebral artery velocity, HR, and mean arterial pressure all significantly increased from baseline after the introduction of isoflurane (p<0.05); the HR and mean arterial blood pressure showed no significant difference between the isoflurane and propofol phases. Isoflurane anesthesia induced a significant increase in cerebral blood velocity. Propofol introduction led to a significant decrease in cerebral artery velocity (p<0.05). CONCLUSIONS: Propofol but not isoflurane decreased cerebral blood velocity thus restoring cerebral autoregulation and the coupling between cerebral blood flow and cerebral metabolism.

Golgi alkalinization by the papillomavirus E5 oncoprotein.

The E5 oncoprotein of bovine papillomavirus type I is a small, hydrophobic polypeptide localized predominantly in the Golgi complex. E5-mediated transformation is often associated with activation of the PDGF receptor (PDGF-R). However, some E5 mutants fail to induce PDGF-R phosphorylation yet retain transforming activity, suggesting an additional mechanism of action. Since E5 also interacts with the 16-kD pore-forming subunit of the vacuolar H(+)-ATPase (V-ATPase), the oncoprotein could conceivably interfere with the pH homeostasis of the Golgi complex. A pH-sensitive, fluorescent bacterial toxin was used to label this organelle and Golgi pH (pH(G)) was measured by ratio imaging. Whereas pH(G) of untreated cells was acidic (6.5), no acidification was detected in E5-transfected cells (pH approximately 7.0). The Golgi buffering power and the rate of H(+) leakage were found to be comparable in control and transfected cells. Instead, the E5-induced pH differential was attributed to impairment of V-ATPase activity, even though the amount of ATPase present in the Golgi complex was unaltered. Mutations that abolished binding of E5 to the 16-kD subunit or that targeted the oncoprotein to the endoplasmic reticulum abrogated Golgi alkalinization and cellular transformation. Moreover, transformation-competent E5 mutants that were defective for PDGF-R activation alkalinized the Golgi lumen. Neither transformation by sis nor src, two oncoproteins in the PDGF-R signaling pathway, affected pH(G). We conclude that alkalinization of the Golgi complex represents a new biological activity of the E5 oncoprotein that correlates with cellular transformation.

The transmembrane domain of the E5 oncoprotein contains functionally discrete helical faces.

The E5 protein of bovine papillomavirus is a 44-amino acid, Golgi-resident, type II transmembrane protein that efficiently transforms immortalized mouse fibroblasts. The transmembrane (TM) domain of E5 is not only critical for biological activity, it also regulates interactions with cellular targets including the platelet derived growth factor receptor (PDGF-R) and the 16-kDa subunit of the vacuolar proton ATPase (V-ATPase). In order to define the specific TM amino acids essential for E5 biological and biochemical activity, we performed scanning alanine mutagenesis on 25 of the 30 potential TM residues and genetically mapped discrete alpha-helical domains which separately regulated the ability of E5 to bind PDGF-R, activate PDGF-R, and to form oligomers. Alanine substitutions at positions 17, 21, and 24 (which lie on the same helical face) greatly inhibited E5 association with the PDGF-R, suggesting that this region comprises the receptor binding site. PDGF-R activation also mapped to a specific but broader domain in E5; mutant proteins with alanines on one helical face (positions 8, 9, 11, 16, 19, 22, and 23) continued to induce PDGF-R tyrosine phosphorylation, whereas mutant proteins with alanines on the opposite helical face (positions 7, 10, 13, 17, 18, 21, 24, and 25) did not, indicating that the latter helical face was critical for mediating receptor transphosphorylation. Interestingly, these "activation-defective" mutants segregated into two classes: 1) those that were unable to form dimers but that could still form higher order oligomers and transform cells, and 2) those that were defective for PDGF-R binding and were transformation-incompetent. These findings suggest that the ability of E5 to dimerize and to bind PDGF-R is important for receptor activation. However, since several transformation-competent E5 mutants were defective for binding and/or activating PDGF-R, it is apparent that E5 must have additional activities to mediate cell transformation. Finally, alanine substitutions also defined two separate helical faces critical for E5/E5 interactions (homodimer formation). Thus, our data identify distinct E5 helical faces that regulate homologous and heterologous intramembrane interactions and define two new classes of biologically active TM mutants.

The serine protease inhibitors TLCK and TPCK react with the RB-binding core of HPV-18 E7 protein and abolish its RB-binding capability.

The human papillomaviruses associated with cervical cancer (e.g., HPV-16 and HPV-18) express an E7 oncoprotein which mediates the immortalization of primary genital keratinocytes and the transformation of rodent cells. The 105-amino-acid HPV-18 E7 protein contains two zinc fingers as well as a conserved amino-terminal motif (Rb-binding core) which binds and alters the interactions of the retinoblastoma susceptibility gene product (Rb). We report here that two serine protease inhibitors, tosyl-L-lysine chloromethyl ketone (TLCK) and tosyl-L-phenylalanine chloromethyl ketone (TPCK), reacted with and generated an altered form of the HPV-18 E7 protein. Chemical modification of the E7 protein was initially observed during its extraction and immunoprecipitation from mammalian cells but could also be detected using E7 protein expressed in vitro by reticulocyte lysates. More importantly, TLCK and TPCK were able to modify E7 protein in live keratinocytes following their addition to the culture medium. Site-specific mutagenesis demonstrated that the E7 Rb-binding core (Leu-X-Cys-X-Glu) contained a cysteine residue which was essential for this modification and that the TLCK/TPCK-dependent alteration of the E7 protein abolished its ability to bind Rb. These studies indicate that the E7 protein can be inactivated by a specific class of protease inhibitors and that such reagents may be useful for pharmacologically regulating E7 function in vivo. In addition, these results demonstrate that care must be taken when applying these commonly used protease inhibitors in experiments evaluating E7/cellular protein interactions.

[Treatment of traumatic injuries of the spleen. Retrospective analysis of 164 cases]. / Trattamento delle lesioni traumatiche della milza. Analisi retrospettiva su 164 casi.

Increased awareness of the spleen's immunologic function and the risk of overwhelming post-splenectomy sepsis has aroused interest in methods of splenic preservation in patients with abdominal trauma. During an 8-year period, 164 patients with documented blunt splenic injuries were treated in accordance with an evolving therapeutic program. Definitive treatment included nonoperative management in 19 patients (group I, 11.6%), repair in 50 (group II, 30.5%) and splenectomy in 95 (group III, 57.9%). Mortality and morbidity were higher in group III (6.3% and 34.3% respectively) according to the Injury Severity Score (ISS 33.3 +/- 13). In group II one patient died from severe head injuries. Only one patient failed nonoperative management and required laparotomy with resultant splenectomy on hospital day 10. Observation without surgery has proved to be safe and effective in children (failure incidence less than 10%); success rates in adults would not parallel the experience reported in children because of differences in anatomy and mechanism of injury. Selective criteria, including hemodynamic stability after initial fluid challenge, normal level of consciousness, lack of peritoneal signs, transfusion requirements of less than 4 units of blood, CT demonstration of minor splenic lesion and exclusion of associated abdominal injuries requiring surgery, make eligible for nonoperative management 12 to 18% of adults with anticipated success in over 75%. Operative repair or partial splenectomy can be employed in many patients, both adults and children, with a 1% incidence of rebleeding necessitating reoperation.

[Lesions of the spleen caused by blunt trauma. Proposal of a classification based on CT and correlation with prognosis and treatment]. / Lesioni della milza da trauma chiuso. Proposta di una classificazione basata sulla TAC e correlazione con prognosi e trattamento.

The use of CT scan has had a profound influence on the evaluation and treatment of closed abdominal injuries, enabling a progressive reduction to be achieved in the total number of emergency laparotomies. The authors review CT performed over the past two years in adult hemodynamically stable patients with traumatic splenic lesions. In 19 cases it was possible to commence non-surgical treatment which was successful in 18/19 cases. A simple and precise scoring system was elaborated on the basis of data obtained from CT by evaluating 4 parameters: extent of free intraperitoneal effusion, concomitant lesions to other abdominal organs, severity and site of splenic lesion. This classification gives a high degree of prognostic accuracy and provides a useful guideline in the choice of the most appropriate treatment.