Synthesis,antitumor activity,molecular modeling,and DNA binding properties of a new series of imidazonaphthalimides

A series of mono and bisintercalators based on the 5,8-dihydrobenz[de]imidazo[4,5-g]isoquinoline-4,6-dione system were synthesized and evaluated for growth inhibitory properties in several human cell lines. All target compounds showed activity in the micromolar range. Representative compounds were evaluated using UV--vis spectroscopy and viscosimetric determinations, showing that they behave as DNA intercalators. Molecular modeling techniques were used in order to rationalize the moderate activity observed for bisnaphthalimides.     

Magnetic resonance imaging measurement of brain edema in patients with liver disease: resolution after transplantation

PURPOSE OF REVIEW: Results from experimental studies indicate that widespread osmotic disturbance induced by astrocytic accumulation of glutamine as a result of ammonia detoxification may lead to brain edema, not only in cases of fulminant hepatic failure, but in the entire spectrum of liver disease. This review summarizes recent magnetic resonance imaging data obtained in patients with chronic liver failure before and after liver transplantation that support the hypothesis that mild brain edema exists in these patients in the absence of clinical hepatic encephalopathy. RECENT FINDINGS: Diffuse white matter abnormalities have been detected with several magnetic resonance imaging techniques such as magnetization transfer ratio measurements, which show significantly low values in otherwise normal appearing brain white matter, and fast-Flair sequences, which show abnormal high-signal intensity of the hemispheric white matter tracts. Both these abnormalities return to normal with restoration of liver function, indicating their reversibility and supporting the hypothesis that they reflect mild diffuse brain edema. SUMMARY: It is likely that magnetic resonance imaging will be increasingly used to evaluate the mechanisms involved in the pathogenesis of hepatic encephalopathy and to assess the effects of therapeutic measures focused on correcting astrocyte swelling in these patients.     

Effects of 14-methoxymetopon, a potent opioid agonist, on the responses to the tail electric stimulation test and plus-maze activity in male rats: neuroendocrine correlates

We have studied the effects of 14-methoxymetopon (HS 198), a potent opioid agonist, on the responses to the tail electric stimulation test and plus-maze activity of adult male rats. The prototype mu agonist morphine was used as the drug of reference. Besides we addressed the effects of HS 198 on the serum corticosterone levels and on serotonergic systems of discrete brain regions. Both drugs were administered subcutaneously. Morphine (5 mg/kg) and HS 198 (30 microg/kg) induced a similar effect on the nociceptive test, with both drugs significantly increasing the threshold for the vocalization afterdischarge, which is related to the emotional component of pain. In the plus-maze, morphine (5 mg/kg) and HS 198 (20 and 30 microg/kg) induced similar increases in the percentages of entries and time in the open arms, two parameters related to the anxiety state of the animals. The results indicate that HS 198 is far more potent than morphine in reducing the emotive/affective component of pain and in inducing an anxiolytic effect. HS 198 (30 microg/kg) also induced parallel increases in the serum corticosterone levels and the hypothalamic serotonin content. A possible correlation between the anxiolytic action of the drug and its effect on the hypothalamic serotonergic system is suggested.     

Investigating the use of primary adult subventricular zone neural precursor cells for neuronal replacement therapies

With the relatively recent discovery that neurogenesis persists throughout life in restricted regions of the adult mammalian brain, including those of human beings, there has been great interest in the use of adult-derived neural stem cells for neuronal replacement. There are many great hurdles that must be overcome in order for such replacement strategies to succeed. In this review, we outline some of these hurdles and discuss recent experiments that investigate the potential of using neural precursor cells found in the subventricular zone of the adult brain for brain repair.     

Prophylactic thyroidectomy in MEN 2A syndrome: experience in a single center

BACKGROUND: Genetic study of the RET proto-oncogene has modified the management, treatment, and prognosis of medullary thyroid carcinoma (MTC), multiple endocrine neoplasia 2A (MEN 2A), for patients with less advanced tumor stages. Classically, the diagnosis was based on an increase in basal and poststimulus peak calcitonin (bCT and pCT). Prophylactic thyroidectomy, based on results of genetic testing, may reduce recurrences in MTC. STUDY DESIGN: Of 82 MTC (MEN 2A) patients genetically diagnosed and surgically treated at our center, 22 received a prophylactic thyroidectomy (RET +, bCT and pCT with normal values and asymptomatic). We analyzed age, gender, phenotype, RET mutation, cervical ultrasound, laboratory tests (bCT, pCT, and CEA), surgery, histologic data, TNM, and followup. RESULTS: The 22 patients belonged to 8 families with MTC (MEN 2A). Mean age was 15.2 years (range 5 to 36 years). The RET mutation in 21 patients was Cys-->Tyr and in the remaining patient both in codon 634 in exon 11. The median values of bCT and pCT were 38 pg/mL (range < 15 to 75 pg/mL) and 148.5 pg/mL (range < 15 to 250 pg/mL), respectively. Total thyroidectomy was performed in 8 patients (age < or = 10 years) and associated central neck dissection in 14 patients (age> 10 years). Histologic study showed 7 C-cell hyperplasias and 15 MTCs (8 bilateral); the median size was 0.2 cm (range < 0.1 to 0.7cm); 1 patient had metastatic adenopathies. According to TNM, 7 were stage 0, 14 were stage I, and 1 was stage III. Postsurgery bCT and pCT values were normal in all patients, with a curative rate of 100%. MTC patients compared with C-cell hyperplasia patients were older on average, had higher mean bCT, mean pCT, and mean CEA. CONCLUSIONS: Prophylactic thyroidectomy based on genetic testing allows identification and treatment of patients at an early stage of the disease and decreases recurrence rates. pCT values above the upper limit of normal may be markers for the presence of MTC and should be considered in selecting operative procedures for these patients.     

A cellular protein with an RNA-binding activity co-purifies with viral dsRNA from mycovirus-infected Helminthosporium victoriae

A cellular protein that co-purifies with mycoviral dsRNA was isolated from the plant pathogenic fungus Helminthosporium victoriae (telomorph: Cochliobolus victoriae) infected with two viruses, the totivirus Helminthosporium victoriae 190S virus and the chrysovirus-like Helminthosporium victoriae 145S virus (Hv145SV). The cellular protein, which was, designated Hv-p68, accumulated to higher levels in virus-infected isolates compared to virus-free ones. The majority of the Hv145S dsRNAs were found in association with Hv-p68 and not packaged in virions. Hv-p68 could also be detected as a minor component of the virus capsid. Evidence is presented that Hv-p68 occurs in vivo as an octamer and that it possesses RNA-binding activities. Based on partial amino acid sequence analysis, Hv-p68 was shown to share significant sequence identity with alcohol oxidases from methylotrophic yeasts. Hv-p68 is proposed to play a role in viral RNA packaging/replication and in regulating viral pathogenesis.     

Idebenone treatment in paediatric and adult patients with Friedreich ataxia: Long-term follow-up

BACKGROUND: Antioxidant therapy is a new therapeutical approach for patients with Friedreich ataxia. AIMS: To assess the effectiveness of long-term idebenone treatment in Friedreich ataxia patients. METHODS: An open-labelled prospective study. Ten paediatric patients (age range 8-18 years) and 14 adults (age range 18-46 years) with genetic diagnosis of Friedreich ataxia were treated with idebenone (5-20mg/kg/day) for 3-5 years. Neurological evolution was evaluated using the International Cooperative Ataxia Rating Scale (ICARS), and cardiological outcomes using echocardiography. RESULTS: In paediatric patients, no significant differences were observed in ICARS scores and echocardiographic measurements when comparing baseline status and after 5 years of follow-up. Concerning adult cases, ICARS scores showed a significant increase in neurological dysfunctions during 3 years of therapy (Wilcoxon test, p=0.005), while echocardiographic measurements remained unchanged. CONCLUSIONS: Our results indicate that longer-term idebenone treatment prevented progression of cardiomyopathy in both paediatric and adult patients, whereas its stabilizing effect on neurological dysfunction was present only in the paediatric population, mainly before puberty. This suggests that the age at which idebenone treatment is initiated may be an important factor in the effectiveness of the therapy.