Discussion on gemcitabine combined with targeted drugs in the treatment of pancreatic cancer

Pancreatic cancer is a malignant tumor with poor prognosis.The treatment of pancreatic cancer depends on the tumor stage and type,and includes local treatment(surgery,radiotherapy and ablation intervention)and systemic therapy(chemotherapy,targeted therapy and immunotherapy).We read with great interest the review“Effective combinations of anti-cancer and targeted drugs for pancreatic cancer treatment”published on World J Gastroenterol and intended to share some of our perspectives in pancreatic cancer treatment.This review presents the therapeutic effects of the combination of gemcitabine and targeted drugs,which gives us a deeper insight into the combination treatments for pancreatic cancer.

Hematologic toxicity of gemcitabine: a comparison between fixed-dose rate infusion and thirty-minute infusion in the treatment of malignancy

Objective： The aim of the study was to compare the hematologic toxicity of gemcitabine between fixed-dose rate （FDR） infusion and 30-minute standard infusion in the treatment of malignancy. Methods： The 25 malignancy patients confirmed by histopathology or cytology received single-agent gemcitabine or gemcitabine in combination with other chemo- therapeutic agents. These patients were randomly divided into gemcitabine 1000 mg/m2 on dl, d8 at a rate of 10 mg/m2/min arm （FDR arm） or 30 rain arm （standard arm）, every 21 days one cycle. Hematologic toxicity was evaluated at the end of each cycle. Results： The 13 of 25 patients received gemcitabine FDR therapy, a total of 28 cycles was completed, and 32 cycles in the others （12 of 25 patients） with the standard arm. All patients were evaluable for hematologic toxicity. The result showed that the grades 3-4 leucopenia was significantly different between the two arms （14.3% vs 0, P 〈 0.05）, and no significant differences of neutropenia, thrombocytopenia and hemoglobin suppression of grades 3-4 （14.3% vs 3.1%, 10.7% vs 3.1%, 3.6% vs 9.4%, P 〉 0.05, respectively） were observed between the two arms, no grade 4 of hemoglobin suppression was observed. Conclusion： Hematologic toxicity of gemcitabine therapy at a fixed-dose rate for malignancy is tolerable.

Human bone marrow mesenchymal stem cell-derived exosomes loaded with gemcitabine inhibit pancreatic cancer cell proliferation by enhancing apoptosis

BACKGROUND Pancreatic cancer remains one of the most lethal malignancies,and has limited effective treatment.Gemcitabine(GEM),a chemotherapeutic agent,is commonly used for clinical treatment of pancreatic cancer,but it has characteristics of low drug delivery efficiency and significant side effects.The study tested the hypothesis that human bone marrow mesenchymal stem cell(MSC)-derived exosomes loaded with GEM(Exo-GEM)would have a higher cytotoxicity against human pancreatic cancer cells by enhancing their apoptosis.AIM To investigate the cytotoxicity of MSC-derived Exo-GEM against pancreatic cancer cells in vitro.METHODS Exosomes were isolated from MSCs and characterized by transmission electron microscopy and nanoparticle tracking analysis.Exo-GEM through electroporation,sonication,or incubation,and the loading efficiency was evaluated.The cytotoxicity of Exo-GEM or GEM alone against human pancreatic cancer Panc-1 and MiaPaca-2 cells was assessed by MTT and flow cytometry assays.RESULTS The isolated exosomes had an average size of 76.7 nm.The encapsulation efficacy and loading efficiency of GEM by electroporation and sonication were similar and significantly better than incubation.The cytotoxicity of Exo-GEM against pancreatic cancer cells was stronger than free GEM and treatment with 0.02μM Exo-GEM significantly reduced the viability of both Panc-1 and MiaPaca-2 cells.Moreover,Exo-GEM enhanced the frequency of GEMinduced apoptosis in both cell lines.CONCLUSION Human bone marrow MSC-derived Exo-GEM have a potent cytotoxicity against human pancreatic cancer cells by enhancing their apoptosis,offering a promising drug delivery system for improving therapeutic outcomes.

Phase Ⅰ/Ⅱ study of gemcitabine and oxaliplatin chemotherapy in combination with concurrent 3-D conformal radiotherapy for locally advanced non-small cell lung cancer

Background and objective Recent studies have showed that combination of chemotherapy and radiotherapy might result in better outcome for locally advanced non-small cell lung cancer (NSCLC). The aim of this study is to determine the maximal tolerance dose (MTD) and efficacy of full-dose gemcitabine and oxaliplatin when given concurrently with 3-dimentional radiation therapy (3D-RT) for locally advanced NSCLC. Methods Oxaliplatin was administered at a fixed dose of 130mg/m^2, and gemcitabine was administered at a starting dose of 800mg/m^2 with an incremental dose gradient of 200mg/m^2 for 3 dose levels. MTD was defined as the immediate dose level lower than the dose at which dose-limiting toxicity (DLT) occurred in more than one-third of the patients. The chemotherapy was administered at 3-week cycle. The RT was given as 3-D conformal manner at a single daily dose of 2Gy for 5 days per week. Results Twenty-two patients were evaluable and distributed to three different dose levels: 6 at level 1, 8 at level 2 and 8 at level 3. Pulmonary toxicity, esophageal and hematologic toxicity were the main DLT. Grade Ⅲ acute pulmonary toxicity occurred in one patient each at level 2 and level 3, both with V20>20%, and grade Ⅲ esophagitis in two patients at level 3. The MTD of gemcitabine in this study was 1000mg/m^2. The overall response rate was 75.0% (9/12). The 1- and 2-year survival rate was 70.0% and 30.5% respectively. The median time to progression was 8.7 months (range 5--11.8 months). Conclusion With reduced radiation volume, gemcitabine of 1000mg/m^2 in combination with oxaliplatin of 130mg/m^2 was effective and could be safely administered for NSCLC.

Oncogenic ADAM28 induces gemcitabine resistance and predicts a poor prognosis in pancreatic cancer

BACKGROUND Pancreatic cancer is a major cause of cancer-related death,with a 5-year overall survival rate being below 5%.The main causes of poor prognosis in pancreatic cancer include easy metastasis,high recurrence rate,and robust drug resistance.Gemcitabine is a first-line drug for patients with unresectable pancreatic cancer.However,due to drug resistance,the clinical effect is not satisfactory.ADAM28 is reported as a tumor promoter in some cancers,but its role in pancreatic cancer and gemcitabine chemoresistance in pancreatic cancer has not been elucidated.AIM To identify if ADAM28 can act as an important target to reverse the gemcitabine drug resistance in pancreatic cancer.METHODS RNA-sequence analysis was applied to explore the potential targets involved in the gemcitabine of pancreatic cancer.SW1990 pancreatic cancer cells were treated with an increased dose of gemcitabine,and the mRNA levels of ADAM28 were evaluated by RT-PCR.The protein and mRNA levels of ADAM28 were confirmed in the gemcitabine resistant and parallel SW1990 cells.The ADAM28 expression was also assessed in TCGA and GEO databases,and the results were confirmed in the collected tumor and adjacent normal tissues.The overall survival(OS)rate and relapse-free survival(RFS)rate of pancreatic cancer patients with high ADAM28 level and low ADAM28 level in TCGA were evaluated with Kaplan-Meier Plotter.Furthermore,the OS rate was calculated in pancreatic cancer patients with high tumor mutation burden(TMB)and low TMB.CCK-8 assay was used to examine the effect of ADAM28 on the viability of SW1990 cells.The ADAM28 and its co-expressed genes were analyzed in the cBioPortal for cancer genomics and subjected to GSEA pathway analysis.The correlations of ADAM28 with GSTP1,ABCC1,GSTM4,and BCL2 were analyzed based on TCGA data on pancreatic cancer.RESULTS RNA-sequence analysis identified that ADAM28 was overexpressed in gemcitabine-resistant cells,and gemcitabine treatment could induce the expression of ADAM28.The mRNA and protein levels of ADAM28 were elevated in gemcitabine-resistant SW1990 cells compared with parallel cells.Also,the expression of ADAM28 was upregulated in pancreatic tumor tissues against normal pancreatic tissues.Notably,ADAM28 was highly expressed in the classical type than in the basal tumor type.Furthermore,the high expression of ADAM28 was associated with low OS and RFS rates.Interestingly,the high levels of ADAM28 was associated with a significantly lower OS rate in the high TMB patients,but not in the low TMB patients.Moreover,overexpression of ADAM28 could reduce the cell viability inhibition by gemcitabine,and knockdown of ADAM28 could enhance the proliferation inhibition by gemcitabine.The GSEA analysis showed that ADAM28 was related to the regulation of drug metabolism,and ADAM28 was significantly positively correlated with GSTP1,ABCC1,GSTM4,and BCL2.CONCLUSION This study demonstrates that ADAM28 is overexpressed in pancreatic cancer,and closely involved in the regulation of gemcitabine resistance.Overexpression of ADAM28 is a novel prognostic biomarker in pancreatic cancer.

Molecular predictors of gemcitabine response in pancreatic cancer

Gemcitabine is one of the most used anti-neoplastic drugs with documented activity in almost all major localizations of cancer.In pancreatic cancer treatment,gemcitabine occupies a prominent place as a first line chemotherapy,partly because of the paucity of other efficacious chemotherapy options.In fact,only a minority of pancreatic cancer patients display a response or even stability of disease with the drug.There are currently no clinically applicable means of predicting which patient will derive a clinical benefit from gemcitabine although several proposed markers have been studied. These markers are proteins involved in drug up-take,activation and catabolism or proteins that define the ability of the cell to undergo apoptosis in response to the drug.Several of these markers are reviewed in this paper.We also briefly discuss the possible role of stem cells in drug resistance to gemcitabine.

ERK signaling pathway may induce gemcitabine chemoresistance in pancreatic cancer cell line SW1990 by regulating the expression of mdr-1 and RRM1 gene

Objective： To investigate the relationship between extracellular signal-regulated kinase （ERK） pathway, multidrug resistance gene （mdr-1）, ribonucleotide recluctase M1 （RRM1） gene and their roles in gemcitabine （GEM） chemoresistance in pancreatic cancer cell line SW1990. Methods： The GEM-resistance cell model was constructed by a stepwise method. Immunohistochemistry was used to measure the expression of ERK protein （ERK1/2） in the established cell strains in a semiquantitative way. The mRNA expression of mdr-1 and RRM1 were detected by RT-PCR. MTT assay was performed to determine the IC50 value. Results： The established GEM-resistant cell strains were able to gain stable growth and passage ability in the medium contained different concentration levels of GEM （0, 30, 60, 100, 150 and 200 nmol/L）. The expression of ERK protein, mdr-1 and RRM1 gene were elevated accompanied by the increase of GEM concentration. There was a highly positive correlation between mdr-1, RRM1 expression and GEM-resistanca level （r = 0.960, P = 0.002 and r = 0.966, P = 0.002）. The expression of ERK protein also correlated with the mdr-1 and RRM1 level （r = -0.943, P = 0.005 and r = -0.883, P = 0.02）. At the GEM-resistance level of 200 nmol/L, the grey scale value of ERK1/2 was 164.22 ±13.17, mdr-1/β-actin and RRM1/β-actin were 1.41 ±0.04 and 1.45 ± 0.18, respectively; after treated with ERK pathway inhibitor U0126, these values synchronously decreased to 186.85 ± 13.14, 0.2 3± 0.02 and 0.21 ± 0.03, respectively; inversely, the ERK1/2 grey scale value was 106.55 ± 16.45, mdr-l/β-actin and RRMl/β-actin were 1.50± 0.07 and 1.52 ± 0.12, respectively, which presented a tendency of synchronously increase after treated with ERK pathway activator EGF. The IC50 values in GEM-resistant cells of 0 nmol/L and 200 nmol/L levels were 4.104 and 10.20, respectively. After treated with U0126, these values decreased to 3.26 and 4.50, respectively; while treated with EGF, the IC50 values increased to 8.89 and 17.17, respectively. Conclusion： The ERK pathway may induce the GEM-chemoresistance in pancreatic cell line SW1990 through the participation in the regulation of the mdr-1 and RRM1 gene expression.

Fixed Dose Rate versus Standard Dose Rate Infusion of Gemcitabine and Cisplatin in Advanced Stage Non-Small Cell Lung Cancer

Background: Comparing the efficacy and safety of gemcitabine at a fixed-dose rate (FDR) infusion (10 mg/m2/min) with the standard dose rate infusion in patients with locally advanced and metastatic non-small squamous cell carcinoma (NSCLC). Methods: The study randomized 60 patients with confirmed diagnosis of NSCLC to receive gemcitabine at a dose of 1000 mg/m2 on days 1 and 8 given as a 30-min infusion (Arm A) or at a rate of 10 mg/m2/min (Arm B). Cisplatin 75 mg/m2 was administered intravenously on day 2 in both arms. Results: No difference in overall response rate (46.6% versus 43.3%). Median time to progression for Arm A was 7 months (95% CI, 6.207 - 7.793 months), versus 6 months for Arm B (95% CI, 4.990 - 7.010 months). Median survival time was comparable [12 months (95% CI, 8.588 - 15.412 months) versus 11 months (95% CI, 9.066 - 12.934 months)] respectively. Two-year survival (18% versus 11%, p = 0.38) was detected. No treatment related deaths occurred. Main hematological toxicities were grade I and II neutropenia, in 36.7% and 53.3% respectively (p = 0.044). Grade III anemia was observed in 10% and 6.7% in both arms respectively (p = 0.024). Grade I and II nausea and vomiting was observed in 50% and 46.7%. Conclusions: FDR gemcitabine in combination with cisplatin had equivalent efficacy and more severe hematologic toxicities compared to the standard 30-min gemcitabine infusion with cisplatin in patients with advanced NSCLC.

Intravesically instilled gemcitabine-induced lung injury in a patient with invasive urothelial carcinoma: A case report

BACKGROUND Gemcitabine is a chemotherapy agent with relatively low toxicities,as a valid option for elderly patients with underlying diseases.Gemcitabine-induced pulmonary toxicities are rare and various,ranging from self-limited episodes of bronchospasm to fatal,progressive,severe,interstitial pneumonitis and respiratory failure.Intravesical gemcitabine instillations are commonly used to reduce recurrence or progression for non-muscle-invasive bladder cancer or urothelial cancer.Few severe toxicities have been reported for the intravesical instillation is assumed to be completely separated from the systemic circulation.CASE SUMMARY A 67-year-old patient received 30 cycles of intravesical gemcitabine instillation after transurethral resection and developed a 1-wk fever,cough,hemoptysis,and dyspnea.After a thorough checkup,bilateral consolidation and infiltration of the lungs were documented and a percutaneous lung biopsy confirmed organizing pneumonia after treatment with broad-spectrum empirical antibiotics failed.Tapered corticosteroids were administered,and pulmonary toxicity gradually resolved.CONCLUSION Gemcitabine-induced pulmonary toxicities present with various manifestations.In spite of the rare pulmonary involvement by the intravesical gemcitabine instillation,health care professionals who administer gemcitabine chemotherapy in this way should monitor for gemcitabine-induced pulmonary toxicities,particularly in patients with high-risk factors.

Clinical analysis of preoperative induction chemotherapy with gemcitabine combined with cisplatin for locally advanced non-small cell lung cancer

Objective:The purpose of this study was to assess the curative effect and adverse reaction of preoperative induction chemotherapy with gemcitabine combined with cisplatin for locally advanced non-small cell lung cancer(NSCLC).Methods:This prospective randomized controlled trial included 115 patients with locally advanced NSCLC were randomly divided into experimental and control groups and were treated from January 2007 to January 2010.The experimental group of 63 cases was treated with two cycles of induction chemotherapy before operation,radical surgery had been performed about three weeks after completion of chemotherapy,followed by received two cycles of chemotherapy.And the control group(52 cases) was treated at first with radical surgery,then treated with four cycles of chemotherapy.Two groups of the cases received routine thoracic radiotherapy with a total dose of 45 Gy.One cycle of gemcitabine combined with cisplatin regimen included gemcitabine 1000 mg/m2 on day 1 and day 8 and cisplatin 25 mg/m2 on day 1,day 2 and day 3 by intravenous infusion,with 21 days as one cycle.The tumor recurrence was evaluated by chest CT and abdominal B-ultrasound.Efficacy and toxicity results were compared by two groups.Results:All patients were followed up for three months to two years.The surgical stage of the experimental group reduced,two-years disease-free survival and postoperative recovery in the experimental group were better than in the control group,the difference was statistical significant.Toxicity and side effect after chemotherapy were mainly bone marrow suppression and gastrointestinal reactions,other complications included thrombocytopenia,leukopenia,anemia,liver and kidney dysfunction were no significant difference in two groups.Conclusion:Preoperative induction chemotherapy with gemcitabine combined with cisplatin for locally advanced lung cancer can reduce the surgical staging and extend the postoperative disease-free survival.

A 3D bio-printed spheroids based perfusion in vitro liver on chip for drug toxicity assays

Liver is the foremost organ of human being for drug metabolism,and it played a significant role in toxicity evaluation of drugs.Establishing a liver model in vitro can accelerate the process of the drug screening and new drug research and development.We provide a 3D printing based hepatic sinusoid-on-a-chip microdevice that reconstitutes organ-level liver functions to create a drug screening model of toxicity evaluation on chip.The microfluidic device,which recapitulates the hepatic sinusoid microenvironment,consists of PET polyporous membranes which mimic the perisinusoidal space,and experience fluid flow to mimic the hepatic arterial capillaries.The PET membrane was used to separate the hepatocyte and endotheliocyte.The endotheliocyte was cultured on the downside of the membrane and the hepatocyte were 3D seeded on the membrane via the 3D printer.This device was used to reproduce the in vitro liver model for drug toxicity assays.The expression of several biomarkers of liver was compared with the monoculture and 2D cultured conditions,and the results reveal that this organ-on-a-chip microdevice mimics the drug hepatoxicity that has not been possible by 2D cell-based and animal models,providing a useful platform for screening the drugs and developing an effective therapy in hepatopathy.

Establishment of porcine and monkey colonic organoids for drug toxicity study

Pig and monkey are widely used models for exploration of human diseases and evaluation of drug efficiency and toxicity,but high cost limits their uses.Organoids have been shown to be promising models for drug test as they reasonably preserve tissue structure and functions.However,colonic organoids of pig and monkey are not yet established.Here,we report a culture medium to support the growth of porcine and monkey colonic organoids.Wnt signaling and PGE2 are important for long-term expansion of the organoids,and their withdrawal results in lineage differentiation to mature cells.Furthermore,we observe that porcine colonic organoids are closer to human colonic organoids in terms of drug toxicity response.Successful establishment of porcine and monkey colonic organoids would facilitate the mechanistic investigation of the homeostatic regulation of the intestine of these animals and is useful for drug development and toxicity studies.

Tolerability and toxicity of adjuvant cisplatin and gemcitabine for treating non-small cell lung cancer

Background The combination of cisplatin and vinorelbine is an evidence-supported regimen for adjuvant chemotherapy for treating non-small cell lung cancer （NSCLC）. But this doublet has considerable toxicity and unfavorable tolerability, and results in poor compliance. The cisplatin and gemcitabine regimen is one of the most active and well-tolerated regimens against advanced NSCLC, but its toxicity and tolerability has not been adequately evaluated in the adjuvant setting. Methods From a lung cancer database we retrospectively reviewed NSCLC patients receiving adjuvant chemotherapy of cisplatin （75 mg/m2） and gemcitabine （1250 mg/m2） between January 2005 and December 2011. Postoperative demographics, compliance to adjuvant therapy and toxicity were retrieved from medical records. Results A total of 132 patients met the criteria and were included in the study, 96 were male （72.7%） and 36 were female （27.3%）. Median age was 60.5 years old, range 29-75 years, and 41.7% of patients were 〉65 years old. Overall, 68.2% patients received all four planned cycles, and the cumulative dose delivered for gemcitabine was 8333 mg （83.3% of the planned dose） and cisplatin 248 mg （82.7% of the planned dose）. There were no treatment-related deaths. Grade 3/4 neutropenia developed in 47 patients （35.6%） and was the predominant hematologic toxicity. Common grade 3/4 non- hematologic toxicities were nausea/vomiting （22.0%）, infection （12.3%）, and febrile neutropenia （11.4%）. Conclusion Cisplatin and gemcitabine are feasible for use in the adjuvant setting with a favorable toxicity profile and superior tolerabilitv compared with Dublished data on cisDlatin and vinorelbine.

Psychotropic drugs and liver disease:A critical review of pharmacokinetics and liver toxicity

The liver is the organ by which the majority of sub-stances are metabolized, including psychotropic drugs. There are several pharmacokinetic changes in end-stage liver disease that can interfere with the metabolization of psychotropic drugs. This fact is particularly true in drugs with extensive first--pass metabolism, highly protein bound drugs and drugs depending on phase I hepatic metabolic reactions. Psychopharmacological agents are also associated with a risk of hepatotoxicity. The evidence is insufficient for definite conclusions regarding the prevalence and severity of psychiatric drug-induced liver injury. High-risk psychotropics are not advised when there is pre-existing liver disease, and after starting a psychotropic agent in a patient with hepatic impairment, frequent liver function/lesion monitoring is advised. The authors carefully review the pharmacokinetic disturbances induced by end-stage liver disease and the potential of psychopharmacological agents for liver toxicity.

Body Composition as A Determinant of Pharmacokinetics and Toxicity of Anticancer Drugs

Chemotherapy-induced toxicity,resulting from inter-individual variability in pharmacokinetics is emerging as a highly active area of investigation.Body composition analysis,primarily concerning the amount of fat mass(FM)and lean body mass(LBM),has provided a proof-concept that the inter-individual variability in pharmacokinetics and toxicity profiles may be partially explained by the discrepancies of FM and LBM in patients.Recent research suggests a close relationship among body composition,pharmacokinetics and toxicity of anticancer drugs.Because LBM and FM,significantly influence the exposure to drugs,they are considered as the promising predictors of chemotherapy-induced toxicity and a potential basis for optimizing the dosing of oncology drugs and the outcomes.Our review summarizes the recent studies rendering the aforementioned correlations to highlight that a critical evaluation of body composition has initiated a new era for dose standardization.

Amphotericin B release rate is the link between drug status in the liposomal bilayer and toxicity

Amphotericin B(AmB)is an amphiphilic drug commonly formulated in liposomes and administered intravenously to treat systemic fungal infections.Recent studies on the liposomal drug product have shed light on the AmB aggregation status in the bilayer,which heat treatment(curing)modifies.Although toxicity was found related to aggregation status-loose aggregates significantly more toxic than tight aggregates-the precise mechanism linking aggregation and toxicitywas notwell understood.This study directlymeasured drug release rate fromvarious AmB liposomal preparations made with modified curing protocols to evaluate correlations among drug aggregation state,drug release,and in vitro toxicity.UV–Vis spectroscopy of these products detected unique curing-induced changes in the UV spectral features:a∼25nm blue-shift of the main absorption peak(λ_(max))in aqueous buffer and a decrease in the OD_(346)/OD_(322) ratio upon thermal curing,reflecting tighter aggregation.In vitro release testing(IVRT)data showed,by applying and fitting first-order release kinetic models for one or two pools,that curing impacts two significant changes:a 3–5-fold drop in the overall drug release rate and a ten-fold decrease in the ratio between the loosely aggregated and the tightly aggregated,more thermodynamically stable drug pool.The kinetic data thus corroborated the trend independently deduced from the UV–Vis spectral data.The in vitro toxicity assay indicated a decreased toxicity with curing,as shown by the significantly increased concentration,causing half-maximal potassium release(TC50).The data suggest that the release of AmB requires dissociation of the tight complexes within the bilayer and that the reduced toxicity relates to this slower rate of dissociation.This study demonstrates the relationship between AmB aggregation status within the lipid bilayer and drug release(directly measured rate constants),providing a mechanistic link between aggregation status and in vitro toxicity in the liposomal formulations.

Biochemical mechanisms in drug-induced liver injury:Certainties and doubts

Drug-induced liver injury is a significant and still unresolved clinical problem. Limitations to knowledge about the mechanisms of toxicity render incomplete the detection of hepatotoxic potential during preclinical development. Several xenobiotics are lipophilic substances and their transformation into hydrophilic compounds by the cytochrome P-450 system results in production of toxic metabolites. Aging, preexisting liver disease, enzyme induction or inhibition, genetic variances, local 02 supply and, above all, the intrinsic molecular properties of the drug may affect this process. Necrotic death follows antioxidant consumption and oxidation of intracellular proteins, which determine increased permeability of mitochondrial membranes, loss of potential, decreased ATP synthesis, inhibition of Ca^2＋-dependent ATPase, reduced capability to sequester Ca^2＋ within mitochondria, and membrane bleb formation. Conversely, activation of nucleases and energetic participation of mitochondria are the main intracellular mechanisms that lead to apoptosis. Non-parenchymal hepatic cells are inducers of hepatocellular injury and targets for damage. Activation of the immune system promotes idiosyncratic reactions that result in hepatic necrosis or cholestasis, in which different HLA genotypes might play a major role. This review focuses on current knowledge of the mechanisms of drug-induced liver injury and recent advances on newly discovered mechanisms of liver damage. Future perspectives including new frontiers for research are discussed.

Neurotoxicity of intrathecal injections of dexmedetomidine into the rat spinal dorsal horn

To investigate the neurotoxicity of intrathecal injections of dexmedetomidine,Sprague-Dawley rats were intrathecally injected with dexmedetomidine at doses of 0.75,1.50 and 3.00μg/kg into the spinal dorsal horn.We found that c-Fos expression in the rat spinal dorsal horn peaked at 7 hours following the 3.00μg/kg dexmedetomidine injection,while the levels of c-Fos expression following 0.75 and 1.50μg/kg dexmedetomidine were similar to those in the spinal dorsal horn of normal rats. At 48 hours following administration,the level of c-Fos expression was similar to normal levels.In addition,the intrathecal injections of dexmedetomidine increased paw withdrawal mechanical thresholds and prolonged thermal tail flick latencies.These results indicate that dexmedetomidine has pronounced antinociceptive effects.However,dexmedetomidine appears to have neurotoxic effects in the spinal cord because it increased c-Fos expression in the spinal dorsal horn within 7 hours following administration.

Thiopurine-methyltransferase variants in inflammatory bowel disease:Prevalence and toxicity in Brazilian patients

AIM: To analyze the prevalence of thiopurine-methyltransferase (TPMT) genotypes and their association with drug toxicity in inflammatory bowel disease (IBD) patients from southeastern Brazil.

A review: Systematic research approach on toxicity model of liver and kidney in laboratory animals

Therapeutic experiments are commonly performed on laboratory animals to inves-tigate the possible mechanism(s)of action of toxic agents as well as drugs or sub-stances under consideration.The use of toxins in laboratory animal models,including rats,is intended to cause toxicity.This study aimed to investigate different models of hepatotoxicity and nephrotoxicity in laboratory animals to help researchers advance their research goals.The current narrative review used databases such as Medline,Web of Science,Scopus,and Embase and appropriate keywords until June 2021.Nephrotoxicity and hepatotoxicity models derived from some toxic agents such as cisplatin,acetaminophen,doxorubicin,some anticancer drugs,and other materials through various signaling pathways are investigated.To understand the models of renal or hepatotoxicity in laboratory animals,we have provided a list of toxic agents and their toxicity procedures in this review.