The effects of rapamycin and 3-methyladenine on nitric oxide synthase enzymes in cisplatin-induced neurotoxicity / Efectos de la rapamicina y la 3-metiladenina sobre la enzima óxido nítrico sintasa en la neurotoxicidad inducida por cisplatino

SUMMARY: The aim of this study was to determine the relationship of autophagy-enhancing rapamycin (RAPA) and autophagy- inhibitor 3-methyladenine (3-MA) with Nitric oxide synthases (NOS) in Cisplatin (CIS)-induced neurotoxicity in rats. Rats were divided into 4 groups (n=10): Control was applied saline, CIS (a single dose of 8mg/kg intraperitoneal (i.p.) on 7th day of experiment), RAPA+CIS (2 mg/kg/i.p. RAPA per day and 8 mg/kg/i.p. CIS on 7th day), 3-MA+CIS (15 mg/kg/i.p. 3-MA per day and 8 mg/kg/i.p. CIS on 7th day). Rats were sacrificed under anesthesia. Brain tissues were evaluated histopathologically. eNOS, Inos, nNOS and MAP 2 immunostaining were performed to determine the expression levels of these proteins among groups. Superoxide dismutase (SOD), Catalase (CAT), Malondialdehyde (MDA) and Interleukin IL-6 levels in brain tissue and serum nitric oxide (NO) level were measured by ELISA assay. In histopathological evaluation, neurodegeneration was seen in the CIS group. There was an increase in eNOS, iNOS and nNOS immunostaining in CIS group. While MAP2 immunostaining of the CIS group decreased. There was a decrease in SOD and CAT levels of brain tissue in CIS group. However, there was an increase in MDA, IL-6 and NO levels of brain tissue in CIS group. We found that antioxidant capacity increase while, inflammation and nitric oxide levels decreased in the RAPA-treated group. 3-MA does not have a significant effect. We suggest that CIS-induced neurotoxicity is more effective than Rapa 3-MA and may also be linked to NOS enzymes.

RESUMEN: El objetivo de este estudio fue determinar la relación de la rapamicina potenciadora de la autofagia (RAPA) y el inhibidor de la autofagia 3-metiladenina (3-MA) con óxido nítrico sintasas (NOS) en la neurotoxicidad inducida por cisplatino (CIS) en ratas. Las ratas se dividieron en 4 grupos (n = 10): grupo control se aplicó solución salina, CIS (una dosis única de 8 mg / kg intraperitoneal (ip) el día 7 del experimento), RAPA + CIS (2 mg / kg / ipRAPA por día y 8 mg / kg / ip CIS el día 7), 3-MA + CIS (15 mg / kg / ip 3-MA por día y 8 mg / kg / ip CIS el día 7). Las ratas se sacrificaron bajo anestesia y los tejidos cerebrales fueron analizados histopatológicamente. Se realizaron inmunotinciones con eNOS, Inos, nNOS y MAP 2 para determinar los niveles de expre- sión de estas proteínas entre los grupos. Se midieron los niveles de superóxido dismutasa (SOD), catalasa (CAT), malondialdehído (MDA) e interleucina IL-6 en el tejido cerebral y el nivel de óxido nítrico (NO) en suero mediante ensayo ELISA. En la evaluación histopatológica, se observó neurodegeneración en el grupo CIS. Hubo un aumento en la inmunotinción de eNOS, iNOS y nNOS en el grupo CIS. Mientras que la inmunotinción de MAP2 del grupo CIS disminuyó. Hubo una disminución en los niveles de SOD y CAT del tejido cerebral en el grupo CIS, sin embargo, hubo un aumento en los niveles de MDA, IL-6 y NO en el tejido cerebral en el grupo CIS. Observamos que la capacidad antioxidante aumentó, mientras que la inflamación y los niveles de óxido nítrico disminuyeron en el grupo tratado con RAPA. 3-MA no tiene un efecto significativo. Sugerimos que la neurotoxicidad inducida por CIS es más eficaz que Rapa 3-MA y también puede estar relacio- nada con las enzimas NOS.

Autophagy inhibitor 3-methyladenine could not modulate rotenone neurotoxicity in primary mesencephalic cell culture / El inhibidor de la autofagia 3-metiladenina no logra modular la neurotoxicidad de la rotenona en el cultivo primario de células mesencefálicas

Dysregulated autophagy, whether excessive or downregulated, has been thought to be associated with neurodegenerative disorders including Parkinson's disease. Accordingly, the present study was carried out to investigate whether 3-methyladenine, an autophagy inhibitor, can modulate the effects of rotenone on dopaminergic neurons in primary mesencephalic cell culture. Cultures were prepared from embryonic mouse mesencephala at gestation day 14. Four groups of cultures were treated on the 10th DIV for 48 h as follows: the first was kept as an untreated control, the second was treated with 3-methyladenine alone (1, 10, 100, 200 mM), the third was treated with 20 nM rotenone and the fourth was co-treated with 20 nM rotenone and 3-methyladenine (1, 10, 100, 200 mM). On the 12th DIV, cultured cells were stained immunohistochemically against tyrosine hydroxylase and culture media were used to measure the levels of lactate dehydrogenase. 3methyladenine had no effects on both the survival of dopaminergic neurons and the release of lactate dehydrogenase. Rotenone significantly decreased the number of dopaminergic neurons and increased the levels of lactate dehydrogenase in the culture media. When cultures concomitantly treated with 3-methyladenine and rotenone, 3-methyladenine had no effect against rotenone-induced dopaminergic cell damage and lactate dehydrogenase release into the culture medium. In conclusion, the autophagy inhibitor 3-methyladenine could not modulate rotenone-induced dopaminergic cell damage in primary mesencephalic cell culture.

Se estima que la autofagia desregulada, ya sea excesiva o con baja regulación, está asociada con trastornos neurodegenerativos, incluyendo la enfermedad de Parkinson. En consecuencia, el se realizó este estudio para investigar si la 3metiladenina, un inhibidor de la autofagia,puede modular los efectos de la rotenona en las neuronas dopaminérgicas en el cultivo primario de células mesencefálicas. Los cultivos se prepararon a partir de mesencéfalo de ratón embrionario el día 14 de gestación. Cuatro grupos de cultivos se trataron en el 10º DIV durante 48 h de la siguiente manera: el primer grupo se mantuvo como un control no tratado, el segundo se trató con 3-metiladenina sola (1, 10, 100, 200 mM), el tercer grupo se trató con rotenona 20 nM y el cuarto se trató conjuntamente con rotenona 20 nM y 3-metiladenina (1, 10, 100, 200 mM). En el 12º DIV; las células cultivadas fueron tratadas mediante tinción inmunohistoquímica en tirosina hidroxilasa y se usaron medios de cultivo para medir los niveles de lactato deshidrogenasa. La 3-metiladenina no tuvo efectos tanto en la supervivencia de las neuronas dopaminérgicas como en la liberación de lactato deshidrogenasa. La rotenona disminuyó significativamente el número de neuronas dopaminérgicas y se observó un aumento de los niveles de lactato deshidrogenasa en los medios de cultivo. Cuando los cultivos tratados concomitantemente con 3-metiladenina y rotenona, la 3metiladenina no tuvo efecto contra el daño celular dopaminérgico inducido por la rotenona y la liberación de lactato deshidrogenasa en el medio de cultivo. En conclusión, el inhibidor de la autofagia 3-metiladenina no moduló el daño celular dopaminérgico inducido por la rotenona en el cultivo celular mesencefálico primario.

Upper urinary tract stone compositions: the role of age and gender

ABSTRACT Objective: To analyze the compositions of upper urinary tract stones and investigate their distributions in different gender and age groups. Materials and Methods: Patients diagnosed with upper urinary tract stone disease between December 2014 and March 2018 were retrospectively reviewed. Patient's age, gender, BMI, comorbidities, stone event characteristics, and compositions were collected, and proportions of stone components in different gender and age groups were analyzed. Results: A total of 1532 stone analyses were performed (992 from males and 540 from females). The mean age was younger in males (p <0.001). Males included more cases with larger BMI, hyperuricemia, and obesity, while females had more urinary tract infections. Multiple components were present in 61.8% of stones. Calcium oxalate (CaOx) (67.0%) was the most common component, followed by uric acid (UA) (11.8%), infection stone (11.4%), calcium phosphate (CaP) (8.0%), cystine (1.1%), brushite (0.4%), and 2, 8-dihydroxyadenine (0.2%). Men contributed with more CaOx stones than women at age 30-49 years (all p <0.01) and more UA stones at 30-59 years (all p <0.05). Women contributed with more infection stones than men in age groups 30-49 and 60-69 years (all p <0.05), and more CaP stones at 30-49 years. The prevalence peak was 50-59 years in men and 60-69 years in women. Both genders had the lowest prevalence in adolescence. Prevalence of UA stones increased while that of infection stones decreased with aging in both genders. Conclusions: Age and sex had a strong association with distribution of stone compositions in this Chinese cohort.

Efficacy of switching from adefovir to tenofovir in chronic hepatitis B patients who exhibit suboptimal responses to adefovir-based combination rescue therapy due to resistance to nucleoside analogues (SATIS study)

BACKGROUND/AIMS: It remains to be determined whether switching from adefovir (ADV) to tenofovir (TDF) provides better virological outcomes in patients exhibiting suboptimal responses to ADV plus nucleoside analogue (ADV+NA) therapy for NA-resistant chronic hepatitis B (CHB). METHODS: In this prospective trial, patients who showed partial responses (defined as serum hepatitis B virus [HBV] DNA >60 IU/mL) to ADV+NA therapy for NA resistance were randomly allocated to receive TDF plus NA (TDF+NA group, n=16) or to continue their current therapy (ADV+NA group, n=16). The primary end point was the proportion of patients with complete virological response (CVR, defined as serum HBV DNA 2log10 IU/mL was more likely in the TDF+NA group at both 24 and 48 weeks (68.8% vs. 56.3%, P=0.014 vs. 81.3% vs. 56.3%, P=0.001, respectively). During the follow-up, the rate of HBeAg seroconversion was higher in the TDF+NA group than the ADV+NA group (12.5% vs. 6.25%, P=0.640), as was that for the hepatitis B surface antigen (6.25% vs. 0%, P=0.080). No serious adverse events due to antiviral agents occurred. CONCLUSIONS: In patients exhibiting suboptimal responses to ADV+NA therapy for NA-resistant CHB, switching from ADV to TDF might provide better virological outcomes.

The efficacy of tenofovir-based therapy in patients showing suboptimal response to entecavir-adefovir combination therapy

BACKGROUND/AIMS: Before tenofovir (TDF) become available in South Korea, combination therapy with entecavir (ETV) and adefovir (ADV) was the most potent regimen for chronic hepatitis B (CHB) patients who fail to respond to rescue therapy for drug resistance. We analyzed the efficacy of ETV-ADV combination therapy and investigated the clinical and clonal results of TDF-based rescue therapy in CHB patients refractory to this combination. METHODS: We retrospectively reviewed the medical records of CHB patients treated for up to 3 years with ETV-ADV combination therapy as a rescue therapy for drug resistance. In cases refractory to this combination, clinical and clonal analyses were performed for TDF-based rescue therapy. RESULTS: The analysis was performed on 48 patients. Twelve patients achieved a virological response (VR) within 3 years. A VR was subsequently achieved in nine of the ten patients without a VR who switched to TDF monotherapy. A VR was also achieved in six of the seven patients who switched to lamivudine-TDF combination therapy, and in two of the two patients who switched to ETV-TDF combination therapy. In an in vitro susceptibility test, viral replication was detected with TDF monotherapy but not with ETV-TDF combination therapy. CONCLUSIONS: The efficacy of ETV-ADV combination therapy was insufficient in CHB patients who were refractory to rescue therapy. A more potent regimen such as ETV-TDF combination therapy may be considered in such refractory cases.

The efficacy of tenofovir-based therapy in patients showing suboptimal response to entecavir-adefovir combination therapy

BACKGROUND/AIMS: Before tenofovir (TDF) become available in South Korea, combination therapy with entecavir (ETV) and adefovir (ADV) was the most potent regimen for chronic hepatitis B (CHB) patients who fail to respond to rescue therapy for drug resistance. We analyzed the efficacy of ETV-ADV combination therapy and investigated the clinical and clonal results of TDF-based rescue therapy in CHB patients refractory to this combination. METHODS: We retrospectively reviewed the medical records of CHB patients treated for up to 3 years with ETV-ADV combination therapy as a rescue therapy for drug resistance. In cases refractory to this combination, clinical and clonal analyses were performed for TDF-based rescue therapy. RESULTS: The analysis was performed on 48 patients. Twelve patients achieved a virological response (VR) within 3 years. A VR was subsequently achieved in nine of the ten patients without a VR who switched to TDF monotherapy. A VR was also achieved in six of the seven patients who switched to lamivudine-TDF combination therapy, and in two of the two patients who switched to ETV-TDF combination therapy. In an in vitro susceptibility test, viral replication was detected with TDF monotherapy but not with ETV-TDF combination therapy. CONCLUSIONS: The efficacy of ETV-ADV combination therapy was insufficient in CHB patients who were refractory to rescue therapy. A more potent regimen such as ETV-TDF combination therapy may be considered in such refractory cases.

Comparison of the clinical outcomes between antiviral-naïve patients treated with entecavir and lamivudine-resistant patients receiving adefovir add-on lamivudine combination treatment

BACKGROUND/AIMS: To analyze the effects of preexisting lamivudine (LAM) resistance and applying antiviral treatment (adefovir [ADV] add-on LAM combination treatment) on long-term treatment outcomes, and comparing the clinical outcomes of antiviral-naïve chronic hepatitis B patients receiving entecavir (ETV) monotherapy. METHODS: This study enrolled 73 antiviral-naïve patients who received 0.5-mg ETV as an initial therapy and 54 patients who received ADV add-on LAM combination treatment as a rescue therapy from July 2006 to July 2010. RESULTS: During 24-month treatments, the decreases in serum log10HBV-DNA values (copies/mL) were significantly greater in the antiviral-naïve patients treated with ETV than the patients receiving ADV add-on LAM combination treatment. The biochemical response rates for alanine aminotransferase normalization at 6 months (ETV) and 12 months (ADV add-on LAM) were 90.4% (66/73) and 77.8% (42/54), respectively (P=0.048). A Kaplan-Meier analysis indicated that the rates of serologic response, viral breakthrough, and emergence of genotypic resistance did not differ significantly between the two patient groups. There were also no significant intergroup differences in the rates of disease progression (PD) and new development of hepatocellular carcinoma (HCC). CONCLUSION: The long-term clinical outcomes of antiviral-naïve patients treated with ETV and LAM-resistant patients receiving ADV add-on LAM combination treatment were comparable in terms of the emergence of HCC and disease progression.

Microarray-based genotyping and detection of drug-resistant HBV mutations from 620 Chinese patients with chronic HBV infection

Background: Research has shown that hepatitis B virus (HBV) genotypes are closely linked to the clinical manifestations, treatment, and prognosis of the disease. Objective: To study the association between genotype and drug-resistant HBV mutations in 620 Chinese patients with chronic HBV infection. Methods: HBV DNA levels were determined using real-time quantitative PCR in plasma samples. Microarrays were performed for the simultaneous detection of HBV genotypes (HBV/B, C, and D) and drug-resistance-related hotspot mutations. A portion of the samples analyzed using microarrays was selected randomly and the data were confirmed using direct DNA sequencing. Results: Most samples were genotype C (471/620; 76.0%), followed by genotype B (149/620; 24.0%). Among the 620 patient samples, 17 (2.7%) had nucleotide analogs (NA) resistance-related mutations. Of these, nine and eight patients carried lamivudine (LAM)-/telbivudine (LdT)-resistance mutations (rtL180M, rtM204I/V) and adefovir (ADV)-resistance mutations (rtA181T/V, rtN236T), respectively. No patients had both lamivudine (LAM)- and either ade-fovir (ADV) or entecavir (ETV) resistance mutations. Additionally, out of the 620 patient samples, 64.0% (397/620) were also detected with the precore stop-codon mutation (G1896A) by microarray assay. Conclusion: The results of the current study revealed that the prevalence of nucleotide analogs (NA)-resistance in Chinese hospitalized HBV-positive patients was so low that intensive nucleotide analogs (NA)-resistance testing before nucleotide analog (NA) treatment might not be required. In addition, the present study suggests that chronic HBV patients with genotype C were infected with fitter viruses and had an increased prevalence of nucleotide analogs (NA)-resistance mutations compared to genotype B virus. .

Entecavir plus tenofovir versus entecavir plus adefovir in chronic hepatitis B patients with a suboptimal response to lamivudine and adefovir combination therapy

BACKGROUND/AIMS: We compared the efficacies of entecavir (ETV) plus tenofovir (TDF) and ETV plus adefovir (ADV) in chronic hepatitis B (CHB) patients with genotypic resistance to lamivudine (LAM) who showed a suboptimal response to LAM and ADV combination therapy. METHODS: We reviewed 63 CHB patients with genotypic resistance to LAM who showed a suboptimal response to LAM and ADV combination therapy. Among these patients, 30 were treated with ETV + ADV and 33 were treated with ETV + TDF for 12 months. RESULTS: The only baseline characteristic that differed significantly between the two groups was the ETV resistance profile. The rate of a virologic response [serum hepatitis B virus (HBV) DNA level of <20 IU/mL] was significant higher for ETV+TDF than for ETV+ADV over 12 months (57.6% vs. 23.3%, P=0.006, at 6 months; 84.8% vs. 26.7%, P<0.001, at 12 months). The probability of a virologic response was significantly increased in ETV+TDF (P<0.001, OR=54.78, 95% CI=7.15-419.54) and decreased in patients with higher baseline viral loads (P=0.001, OR=0.18, 95% CI=0.07-0.50) in multivariate analysis. No serious adverse event occurred during the study period. CONCLUSIONS: In patients with CHB who showed a suboptimal response to LAM and ADV combination therapy, ETV+TDF was superior to ETV+ADV in achieving a virologic response regardless of the HBV resistance profile. Further large-scale and long-term follow-up prospective studies are needed to explain these results.

Is tenofovir disoproxil fumarate an all-powerful weapon in the treatment of chronic hepatitis B?

No abstract available.

Compounds used to produce cloned animals are genotoxic and mutagenic in mammalian assays in vitro and in vivo

The compounds 6-dimethylaminopurine and cycloheximide promote the successful production of cloned mammals and have been used in the development of embryos produced by somatic cell nuclear transfer. This study investigated the effects of 6-dimethylaminopurine and cycloheximide in vitro, using the thiazolyl blue tetrazolium bromide colorimetric assay to assess cytotoxicity, the trypan blue exclusion assay to assess cell viability, the comet assay to assess genotoxicity, and the micronucleus test with cytokinesis block to test mutagenicity. In addition, the comet assay and the micronucleus test were also performed on peripheral blood cells of 54 male Swiss mice, 35 g each, to assess the effects of the compounds in vivo. The results indicated that both 6-dimethylaminopurine and cycloheximide, at the concentrations and doses tested, were cytotoxic in vitro and genotoxic and mutagenic in vitro and in vivo, altered the nuclear division index in vitro, but did not diminish cell viability in vitro. Considering that alterations in DNA play important roles in mutagenesis, carcinogenesis, and morphofunctional teratogenesis and reduce embryonic viability, this study indicated that 6-dimethylaminopurine and cycloheximide utilized in the process of mammalian cloning may be responsible for the low embryo viability commonly seen in nuclear transfer after implantation in utero.

Rescue therapy with adefovir in decompensated liver cirrhosis patients with lamivudine-resistant hepatitis B virus

BACKGROUND/AIMS: Adefovir dipivoxil (ADV) is a nucleotide analogue that is effective against lamivudine-resistant hepatitis B virus (HBV). The aim of this study was to determine the long-term clinical outcomes after ADV rescue therapy in decompensated patients infected with lamivudine-resistant HBV. METHODS: In total, 128 patients with a decompensated state and lamivudine-resistant HBV were treated with ADV at a dosage of 10 mg/day for a median of 33 months in this multicenter cohort study. RESULTS: Following ADV treatment, 86 (72.3%) of 119 patients experienced a decrease in Child-Pugh score of at least 2 points, and the overall end-stage liver disease score decreased from 16+/-5 to 14+/-10 (mean +/- SD, P or =2 points; P=0.001) and high mortality following ADV rescue therapy (P=0.012). CONCLUSIONS: Three years of ADV treatment was effective and safe in decompensated patients with lamivudine-resistant HBV.

Efficacy and Safety of Tenofovir-Based Rescue Therapy for Chronic Hepatitis B Patients with Previous Nucleo(s/t)ide Treatment Failure

BACKGROUND/AIMS: We investigated the efficacy and safety of tenofovir disoproxil fumarate (TDF)-based treatment in chronic hepatitis B (CHB) patients who failed previous antiviral therapies. METHODS: Seventeen patients who failed to achieve virological responses during sequential antiviral treatments were included. The patients were treated with TDF monotherapy (four patients) or a combination of TDF and lamivudine (13 patients) for a median of 42 months. Hepatitis B virus (HBV) DNA and hepatitis B e antigen (HBeAg) were measured, and renal function was also monitored. RESULTS: Prior to TDF therapy, 180 M, 204 I/V/S, 181 T/V, 236 T, and 184 L mutations were detected. After TDF therapy, the median HBV DNA level decreased from 4.6 log10 IU/mL to 2.0 log10 IU/mL and to 1.6 log10 IU/mL at 12 and 24 months, respectively. HBV DNA became undetectable (< or =20 IU/mL) in 14.3%, 41.7%, and 100% of patients after 12, 24, and 48 months of treatment, respectively. HBeAg loss was observed in two patients. Viral breakthrough occurred in five patients who had skipped their medication. No significant changes in renal function were observed. CONCLUSIONS: TDF-based rescue treatment is effective in reducing HBV DNA levels and is safe for patients with CHB who failed prior antiviral treatments. Patients' adherence to medication is related to viral rebound.

Analysis of Reverse Transcriptase Gene Mutations in the Hepatitis B Virus at a University Hospital in Korea

BACKGROUND: Most mutations in the reverse transcriptase (RT) gene of the hepatitis B virus (HBV) are related to resistance to antiviral agents. Cross-sectional studies on the mutations of this gene are rare. Thus, we analyzed the mutation patterns of RT genes and their biochemical parameters. METHODS: From 2009 to 2012, 301 blood specimens from patients with chronic hepatitis B at Daegu Catholic University Medical Center were retrospectively analyzed for the RT gene sequence of HBV, ALT, hepatitis B e antigen (HBeAg), and HBV DNA. The mutation patterns of the RT gene were compared with the biochemical parameters. RESULTS: Of the 301 patients, 100 (33.2%) had no RT gene mutations. The remaining showed the following mutation patterns: rtM204I/V (50.2%), rtL180M (39.2%), and rtA181T/V (19.6%). Combined mutations were found in 146 cases (48.5%). Of these, the combination of amino acid changes at rt180+rt204 (49.3%) was most frequently detected, followed by rt181+rt236 (11.0%) and rt173+rt180+rt204 (9.6%). In the mutated group, HBV DNA and HBeAg positive rates were significantly higher (P<0.05 for both). Phenotypic analysis showed that lamivudine resistance was most frequently detected (34.6%), followed by adefovir resistance (15.6%). Multidrug resistance was detected in 48 cases (15.9%). The adefovir-resistant group had a higher proportion of cases with HBV loads greater than 2,000 IU/mL. CONCLUSIONS: We found correlations between the mutation status of the RT domain and biochemical parameters such as HBV DNA and HBeAg positive rate. The presence of RT gene mutations could therefore be utilized to predict clinical status.

Long-term outcomes of two rescue therapies in lamivudine-refractory patients with chronic hepatitis B: combined lamivudine and adefovir, and 1-mg entecavir

BACKGROUND/AIMS: Adefovir (ADV) and lamivudine (LAM) combination therapy (ADV+LAM) has been a useful option for patients with LAM-resistant (LAM-r) chronic hepatitis B (CHB). However, the long-term outcomes of LAM+ADV and 1-mg entecavir (ETV) rescue therapies have still been limited. The aim of this study was to determine the long-term outcomes of these two rescue therapies. METHODS: Sixty patients with LAM-r CHB underwent rescue therapy with LAM+ADV (n=36) or 1-mg ETV (n=24). We determined the duration of rescue therapy, timing and type of mutation, undetectable serum hepatitis B virus (HBV) DNA by PCR (lower limitation of detection, < 140 copies/mL), biochemical response (alanine aminotransferase < 40 IU/mL), and the incidence of hepatitis B virus e antigen (HBeAg) seroconversion and virologic breakthrough. RESULTS: Baseline characteristics did not differ between the two therapy groups. The duration of rescue therapy was 56 months (range, 14-100 months) in the ADV+LAM group and 42 months (range, 12-73 months) in the ETV group (P=0.036). The cumulative rates of HBV DNA undetectability and HBeAg seroconversion up to 6 years were 88.6% and 43.0%, respectively, in the ADV+LAM group, and 45.8% and 31.8% in the ETV group. The rate of virologic breakthrough and resistance was 14.4% in the ADV+LAM group and 71.9% in the ETV group (P=0.001). CONCLUSIONS: Combination of LAM and ADV therapy for up to 6 years achieved modest rates of virological suppression and resistance. ETV is not an optimal therapy because the risk of viral breakthrough to ETV increases over time.

Ischemia preconditioning is neuroprotective in a rat cerebral ischemic injury model through autophagy activation and apoptosis inhibition

Sublethal ischemic preconditioning (IPC) is a powerful inducer of ischemic brain tolerance. However, its underlying mechanisms are still not well understood. In this study, we chose four different IPC paradigms, namely 5 min (5 min duration), 5×5 min (5 min duration, 2 episodes, 15-min interval), 5×5×5 min (5 min duration, 3 episodes, 15-min intervals), and 15 min (15 min duration), and demonstrated that three episodes of 5 min IPC activated autophagy to the greatest extent 24 h after IPC, as evidenced by Beclin expression and LC3-I/II conversion. Autophagic activation was mediated by the tuberous sclerosis type 1 (TSC1)-mTor signal pathway as IPC increased TSC1 but decreased mTor phosphorylation. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and hematoxylin and eosin staining confirmed that IPC protected against cerebral ischemic/reperfusion (I/R) injury. Critically, 3-methyladenine, an inhibitor of autophagy, abolished the neuroprotection of IPC and, by contrast, rapamycin, an autophagy inducer, potentiated it. Cleaved caspase-3 expression, neurological scores, and infarct volume in different groups further confirmed the protection of IPC against I/R injury. Taken together, our data indicate that autophagy activation might underlie the protection of IPC against ischemic injury by inhibiting apoptosis.

Antivirais incorporados no Brasil para hepatite B cronica: analise de custo-efetividade / Antivirales incorporados en Brasil para hepatitis B cronica: analisis de costo-efectividad / Incorporated antivirals for chronic hepatitis B in Brazil: a cost-effectiveness analysis

OBJETIVO Avaliar o custo-efetividade de diferentes tratamentos medicamentosos para hepatite B crônica entre pacientes adultos. MÉTODOS Utilizando modelo de Markov, construiu-se coorte hipotética de 40 anos para pacientes HBeAg-positivo ou HBeAg-negativo. Foram comparados os usos de adefovir, entecavir, tenofovir e lamivudina (com terapia de resgate em caso de resistência viral) para tratamento de pacientes adultos com hepatite B crônica, virgens de tratamento, com elevados níveis de alanina aminotransferase, sem evidência de cirrose e sem coinfecção por HIV. Valores para custo e efeito foram obtidos da literatura. A medida do efeito foi expressa em anos de vida ganhos (AVG). Taxa de desconto de 5% foi aplicada. Análise de sensibilidade univariada foi conduzida para avaliar incertezas do modelo. RESULTADOS O tratamento inicial com entecavir ou tenofovir apresentou melhores resultados clínicos. As menores razões custo-efetividade foram de entecavir para pacientes HBeAg-positivo (R$ 4.010,84/AVG) e lamivudina para pacientes HBeAg-negativo (R$ 6.205,08/AVG). Para pacientes HBeAg-negativo, a razão custo-efetividade incremental de entecavir (R$ 14.101,05/AVG) está abaixo do limiar recomendado pela Organização Mundial da Saúde. Análise de sensibilidade mostrou que variação nos custos dos medicamentos pode tornar tenofovir alternativa custo-efetiva tanto para pacientes HBeAg-positivo quanto para HBeAg-negativo. CONCLUSÕES Entecavir é alternativa recomendada para iniciar o tratamento de pacientes com hepatite B crônica no Brasil. Contudo, se houver redução no custo de tenofovir, esta pode se tornar alternativa mais custo-efetiva. .

OBJETIVO Evaluar el costo-efectividad de diferentes tratamientos medicamentosos para hepatitis B crónica entre pacientes adultos. MÉTODOS Utilizando el modelo de Markov, se construyó cohorte hipotética de 40 años para pacientes HBeAg-positivo o HBeAg-negativo. Se compararon los usos de adefovir, entecavir, tenofovir y lamivudina (con terapia de rescate en caso de resistencia viral) para tratamiento de pacientes adultos con hepatitis B crónica, vírgenes de tratamiento, con elevados niveles de alanina aminotransferasa, sin evidencia de cirrosis y sin coinfección por VIH. Valores para costo y efecto fueron obtenidos de la literatura y efecto en años de vida ganados (AVG). Tasa de descuento de 5% fue aplicada. Análisis de sensibilidad univariado fue conducido para evaluar incertidumbres del modelo. RESULTADOS El tratamiento inicial con entecavir o tenofovir presentó mejores resultados clínicos. Los menores cocientes costo-efectividad fueron de entecavir para pacientes HBeAg-positivo (R.010,84/AVG) y lamivudina para pacientes HBeAg-negativo (R.205,08/AVG).Para pacientes HBeAg-negativo, el cociente costo-efectividad incrementado de entecavir (R.101,05/AVG) está por debajo del límite recomendado por la Organización Mundial de la Salud. El análisis de sensibilidad mostró que la variación en los costos de los medicamentos puede tornar tenofovir una alternativa costo-efectiva tanto para pacientes HBeAg-positivo como para los HBeAg-negativo. CONCLUSIONES Entecavir es una alternativa recomendada para iniciar el tratamiento de pacientes con hepatitis B crónica en Brasil. Sin embargo, al haber reducción en el costo de tenofovir, éste puede convertirse en una alternativa más costo-efectiva. .

OBJECTIVE To evaluate the cost-effectiveness of different drug therapies for chronic hepatitis B in adult patients. METHODS Using a Markov model, a hypothetical cohort of 40 years for HBeAg-positive or HBeAg-negative patients was constructed. Adefovir, entecavir, tenofovir and lamivudine (with rescue therapy in cases of viral resistance) were compared for treating adult patients with chronic hepatitis B undergoing treatment for the first time, with high levels of alanine aminotransferase, no evidence of cirrhosis and without HIV co-infection. Values for cost and effect were obtained from the literature, and expressed in effect on life years (LY). A discount rate of 5% was applied. Univariate sensitivity analysis was conducted to assess model uncertainties. RESULTS Initial treatment with entecavir or tenofovir showed better clinical outcomes. The lowest cost-effectiveness ratio was for entecavir in HBeAg-positive patients (R$ 4,010.84/LY) and lamivudine for HBeAg-negative patients (R$ 6,205.08/LY). For HBeAg-negative patients, the incremental cost-effectiveness ratio of entecavir (R$ 14,101.05/LY) is below the threshold recommended by the World Health Organization. Sensitivity analysis showed that variation in the cost of drugs may make tenofovir a cost-effective alternative for both HBeAg-positive and HBeAg-negative patients. CONCLUSIONS Entecavir is the recommended alternative to start treating patients with chronic hepatitis B in Brazil. However, if there is a reduction in the cost of tenofovir, it can become a cost-effective alternative. .

Economic evaluation of treatments for chronic hepatitis B

The aim of this study was to conduct a cost-utility study of adefovir, entecavir, interferon alpha, pegylated interferon alpha, lamivudine and tenofovir for chronic hepatitis B in the context of Brazilian Public Health Care System. A systematic review was carried out for efficacy and safety. Another review was performed to collect utility data and transition probabilities between health states. A Markov model was developed in a time horizon of 40 years with annual cycles for three groups of: HBeAg positive, HBeAg negative, and all patients. These strategies were compared to a fourth group that received no treatment. Discount rates of 5% were applied and sensitivity analyses were performed. Tenofovir offered the best cost-utility ratio for the three evaluated models: U$397, U$385 and U$384 (per QALY, respectively, for HBeAg positive, negative, and all patients). All other strategies were completely dominated because they showed higher costs and lower effectiveness than tenofovir. The sequence of cost-utility in the three models was: tenofovir, entecavir, lamivudine, adefovir, telbivudine, pegylated interferon alpha, and interferon alpha. In the sensitivity analysis, adefovir showed lower cost-utility than telbivudine in some situations. The study has some limitations, primarily related to the creation of scenarios and modeling. In this study, tenofovir presented the best cost-utility ratio. The results obtained in this study will be valuable in decision-making and in the review of the clinical protocol, mainly involving the allocation of available resources for health care.

Detection of rtN236T mutation associated with adefovir dipivoxil resistance in hepatitis B infected patients with YMDD mutations in Tehran

The risk of adefovir dipivoxil resistance emergence has increased in lamivudine-resistant hepatitis B infected patients. The mutations known as causing adefovir resistance, rtN236T and rtA181V/T, are detected within the D and B functional domain of the HBV polymerase, respectively. In this study, we intended to determine the pre-existing adefovir-resistance mutations in patients infected with LAM resistant mutants prior to starting adefovir therapy. The study included 30 patients with chronic hepatitis B with lamivudine resistance mutations in the YMDD motif that experienced viral breakthrough. After alignment of protein coding sequences, the rtN236T mutation was observed in two [6.6%] patients, while twenty-eight others had neither rtN236T, nor rtA181V/T mutation. All 30 patients were infected with genotype D of hepatitis B virus. The early detection ofLAM-resistance mutations may allow a timely chance of therapy to avoid hepatitis flare- up. This data suggests that monitoring of ADV-resistance mutations in ADV naive patients can be considered in selecting the appropriate anti-viral regimen

Options for the management of antiviral resistance during hepatitis B therapy: reflections on battles over a decade

Although much advancement has been achieved in the treatment of chronic hepatitis B, antiviral resistance is still a challenging issue. Previous generation antiviral agents have already developed resistance in a number of patients, and it is still being used especially in resource limited countries. Once antiviral resistance occurs, it predisposes to subsequent resistance, resulting in multidrug resistance. Therefore, prevention of initial antiviral resistance is the most important strategy, and appropriate choice and modification of therapy would be the cornerstone in avoiding treatment failures. Until now, management of antiviral resistance has been evolving from sequential therapy to combination therapy. In the era of tenofovir, the paradigm shifts again, and we have to decide when to switch and when to combine on the basis of newly emerging clinical data. We expect future eradication of chronic hepatitis B virus infection by proper prevention and optimal management of antiviral resistance.