- Upper Gastrointestinal Bleeding in Aluminium Phosphide Poisoning. [Journal Article]
- KUKathmandu Univ Med J (KUMJ) 2017 Jan.-Mar.; 15(57):99-101
- Aluminium phosphide is one of the most common poisons used for suicide in an agricultural country like India. Death is usually due to myocarditis which occurs within few hours of ingestion. There are...
Aluminium phosphide is one of the most common poisons used for suicide in an agricultural country like India. Death is usually due to myocarditis which occurs within few hours of ingestion. There are many late complications reported in medical literature, however toxic effects on the gastrointestinal system, particularly corrosive action leading to massive haemorrhage is rarely reported. A 30 year old male developed upper gastrointestinal bleeding on the second day after consumption of aluminium phosphide. An exploratory laprotomy was done followed by adhesinolysis, gastrostomy closure with feeding jejunostomy and drainage. He died after eight days of ingestion. The autopsy findings of this rarely reported case along with review of literature on corrosive action of Aluminium Phosphide is discussed.
- A local strain of Paprika mild mottle virus breaks L3resistance in peppers and is accelerated in Tomato brown rugose fruit virus-infected Tm-22-resistant tomatoes. [Journal Article]
- VGVirus Genes 2018 Feb 10
- During October 2014, unfamiliar mild mosaic and mottling symptoms were identified on leaves of pepper (Capsicum chinense cv. Habanero) seedlings grown in the Arava valley in Israel 2-3 weeks post pla...
During October 2014, unfamiliar mild mosaic and mottling symptoms were identified on leaves of pepper (Capsicum chinense cv. Habanero) seedlings grown in the Arava valley in Israel 2-3 weeks post planting. Symptomatic plants were tested positive by ELISA using laboratory-produced antisera for tobamovirus species. Typical tobamovirus rod-shaped morphology was observed by transmission electron microscopy (TEM) analysis of purified virion preparation that was used for mechanical inoculation of laboratory test plants for the completion of Koch's postulates. The complete viral genome was sequenced from small interfering RNA purified from symptomatic pepper leaves and fruits by next-generation sequencing (NGS) using Illumina MiSeq platform. The contigs generated by the assembly covered 80% of the viral genome. RT-PCR amplification and Sanger sequencing were employed in order to validate the sequence generated by NGS technology. The nucleotide sequence of the complete viral genome was 99% identical to the complete genome of Paprika mild mottle virus isolate from Japan (PaMMV-J), and the deduced amino acid sequence was 99% identical to PaMMV-J protein. Amplicons from seed RNA showed 100% identity to the viral isolate from the collected symptomatic pepper plants. Partial host range analysis revealed a slow development of systemic infection in inoculated tomato plants (Lycopersicon esculentum). Interestingly, double inoculation of susceptible wild-type tomato plants and Tm-22-resistant tomato plants with the PaMMV-IL and Tomato brown rugose fruit virus (ToBRFV) resulted in accelerated viral expression in the plants.
- Mitochondrial dysfunction induced by leflunomide and its active metabolite. [Journal Article]
- TToxicology 2018 Feb 07
- Leflunomide, an anti-inflammatory drug used for the treatment of rheumatoid arthritis, has been marked with a black box warning regarding an increased risk of liver injury. The active metabolite of l...
Leflunomide, an anti-inflammatory drug used for the treatment of rheumatoid arthritis, has been marked with a black box warning regarding an increased risk of liver injury. The active metabolite of leflunomide, A771726, which also carries a boxed warning about potential hepatotoxicity, has been marketed as teriflunomide for the treatment of relapsing multiple sclerosis. Thus far, however, the mechanism of liver injury associated with the two drugs has remained elusive. In this study, cytotoxicity assays showed that ATP depletion and subsequent LDH release were induced in a time- and concentration-dependent manner by leflunomide in HepG2 cells, and to a lesser extent, by A77 1726. The decline of cellular ATP levels caused by leflunomide was dramatically exacerbated when galactose was substituted for glucose as the sugar source, indicating a potential mitochondrial liability of leflunomide. By measuring the activities of immuno-captured mitochondrial oxidative phosphorylation (OXPHOS) complexes, we found that leflunomide and A77 1726 preferentially targeted complex V (F1FOATP synthase), with IC50values of 35.0 and 63.7 μM, respectively. Bongkrekic acid, a mitochondrial permeability transition pore blocker that targets adenine nucleotide translocase, profoundly attenuated mitochondrial membrane depolarization, ATP depletion, and LDH leakage induced by leflunomide and A77 1726. Substantial alterations of mitochondrial function at the transcript level were observed in leflunomide-treated HepG2 cells, whereas the effects of A77 1726 on the cellular transcriptome were much less profound. Our results suggest that mitochondrial dysfunction may be implicated in the hepatotoxicity associated with leflunomide and A77 1726, with the former exhibiting higher toxicity potency.
- The anti-rheumatic drug, leflunomide, synergizes with MEK inhibition to suppress melanoma growth. [Journal Article]
- OOncotarget 2018 Jan 09; 9(3):3815-3829
- Cutaneous melanoma, which develops from the pigment producing cells called melanocytes, is the most deadly form of skin cancer. Unlike the majority of other cancers, the incidence rates of melanoma a...
Cutaneous melanoma, which develops from the pigment producing cells called melanocytes, is the most deadly form of skin cancer. Unlike the majority of other cancers, the incidence rates of melanoma are still on the rise and the treatment options currently available are being hindered by resistance, limited response rates and adverse toxicity. We have previously shown that an FDA approved drug leflunomide, used for rheumatoid arthritis (RA), also holds potential therapeutic value in treating melanoma especially if used in combination with the mutant BRAF inhibitor, vemurafenib. We have further characterized the function of leflunomide and show that the drug reduces the number of viable cells in both wild-type and BRAFV600E mutant melanoma cell lines. Further experiments have revealed leflunomide reduces cell proliferation and causes cells to arrest in G1 of the cell cycle. Cell death assays show leflunomide causes apoptosis at treatment concentrations of 25 and 50 µM. To determine if leflunomide could be used combinatorialy with other anti-melanoma drugs, it was tested in combination with the MEK inhibitor, selumetinib. This combination showed a synergistic effect in the cell lines tested. This drug combination led to an enhanced decrease in tumor size when tested in vivo compared to either drug alone, demonstrating its potential as a novel combinatorial therapy for melanoma.
- Blaschkoid Acute Graft-vs-Host Disease. [Journal Article]
- JDJAMA Dermatol 2018 Jan 31
- The extent of ribosome queuing in budding yeast. [Journal Article]
- PCPLoS Comput Biol 2018; 14(1):e1005951
- Ribosome queuing is a fundamental phenomenon suggested to be related to topics such as genome evolution, synthetic biology, gene expression regulation, intracellular biophysics, and more. However, th...
Ribosome queuing is a fundamental phenomenon suggested to be related to topics such as genome evolution, synthetic biology, gene expression regulation, intracellular biophysics, and more. However, this phenomenon hasn't been quantified yet at a genomic level. Nevertheless, methodologies for studying translation (e.g. ribosome footprints) are usually calibrated to capture only single ribosome protected footprints (mRPFs) and thus limited in their ability to detect ribosome queuing. On the other hand, most of the models in the field assume and analyze a certain level of queuing. Here we present an experimental-computational approach for studying ribosome queuing based on sequencing of RNA footprints extracted from pairs of ribosomes (dRPFs) using a modified ribosome profiling protocol. We combine our approach with traditional ribosome profiling to generate a detailed profile of ribosome traffic. The data are analyzed using computational models of translation dynamics. The approach was implemented on the Saccharomyces cerevisiae transcriptome. Our data shows that ribosome queuing is more frequent than previously thought: the measured ratio of ribosomes within dRPFs to mRPFs is 0.2-0.35, suggesting that at least one to five translating ribosomes is in a traffic jam; these queued ribosomes cannot be captured by traditional methods. We found that specific regions are enriched with queued ribosomes, such as the 5'-end of ORFs, and regions upstream to mRPF peaks, among others. While queuing is related to higher density of ribosomes on the transcript (characteristic of highly translated genes), we report cases where traffic jams are relatively more severe in lowly expressed genes and possibly even selected for. In addition, our analysis demonstrates that higher adaptation of the coding region to the intracellular tRNA levels is associated with lower queuing levels. Our analysis also suggests that the Saccharomyces cerevisiae transcriptome undergoes selection for eliminating traffic jams. Thus, our proposed approach is an essential tool for high resolution analysis of ribosome traffic during mRNA translation and understanding its evolution.
- Inhibition of angiogenesis by leflunomide via targeting the soluble ephrin-A1/EphA2 system in bladder cancer. [Journal Article]
- SRSci Rep 2018 Jan 24; 8(1):1539
- Angiogenesis plays an important role in bladder cancer (BCa). The immunosuppressive drug leflunomide has attracted worldwide attention. However, the effects of leflunomide on angiogenesis in cancer r...
Angiogenesis plays an important role in bladder cancer (BCa). The immunosuppressive drug leflunomide has attracted worldwide attention. However, the effects of leflunomide on angiogenesis in cancer remain unclear. Here, we report the increased expression of soluble ephrin-A1 (sEphrin-A1) in supernatants of BCa cell lines (RT4, T24, and TCCSUP) co-cultured with human umbilical vein endothelial cells (HUVECs) compared with that in immortalized uroepithelial cells (SV-HUC-1) co-cultured with HUVECs. sEphrin-A1 is released from BCa cells as a monomeric protein that is a functional form of the ligand. The co-culture supernatants containing sEphrin-A1 caused the internalization and down-regulation of EphA2 on endothelial cells and dramatic functional activation of HUVECs. This sEphrin-A1/EphA2 system is mainly functional in regulating angiogenesis in BCa tissue. We showed that leflunomide (LEF) inhibited angiogenesis in a N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN)-induced bladder carcinogenesis model and a tumor xenograft model, as well as in BCa cell and HUVEC co-culture systems, via significant inhibition of the sEphrin-A1/EphA2 system. Ephrin-A1 overexpression could partially reverse LEF-induced suppression of angiogenesis and subsequent tumor growth inhibition. Thus, LEF has a significant anti-angiogenesis effect on BCa cells and BCa tissue via its inhibition of the functional angiogenic sEphrin-A1/EphA2 system and may have potential for treating BCa beyond immunosuppressive therapy.
- Leflunomide: A promising drug with good antitumor potential. [Review]
- BBBiochem Biophys Res Commun 2018 02 05; 496(2):726-730
- Leflunomide, an inhibitor of dihydroorotase dehydrogenase and thereby pyrimidine synthesis, was approved for treatment of rheumatoid arthritis in 1998. During the following years, leflunomide was use...
Leflunomide, an inhibitor of dihydroorotase dehydrogenase and thereby pyrimidine synthesis, was approved for treatment of rheumatoid arthritis in 1998. During the following years, leflunomide was used in various preclinical studies as a potential cancer treatment; at the same time, more mechanisms underlying the anticancer effect of leflunomide were identified. Thus, leflunomide has been identified as a potent anticancer drug. This article summarizes the mechanisms as well as results of leflunomide in the evolving field of cancer therapy.
- Inactivation/deficiency of DHODH induces cell cycle arrest and programed cell death in melanoma. [Journal Article]
- OOncotarget 2017 Dec 22; 8(68):112354-112370
- Malignant melanoma (MM) is one of the most malignant tumors and has a very poor prognosis. However, there are no effective drugs to treat this disease. As a kind of iron flavin dependent enzyme, dihy...
Malignant melanoma (MM) is one of the most malignant tumors and has a very poor prognosis. However, there are no effective drugs to treat this disease. As a kind of iron flavin dependent enzyme, dihydroorotate dehydrogenase (DHODH, EC 184.108.40.206) is the fourth and a key enzyme in the de novo biosynthesis of pyrimidines. Herein, we found that DHODH inactivation/deficiency inhibited melanoma cell proliferation, induced cell cycle arrest at S phase and lead to autophagy in human melanoma cells. Meanwhile, leflunomide treatment induced cell apoptosis and deficiency of DHODH sensitized cells to drug-induced apoptosis in BCL-2 deficient melanoma cells, while not in BCL-2 abundant melanoma cells. Then we found that BCL-2 could rescue apoptosis induced by DHODH inactivation/deficiency. Moreover, BCL-2 also showed to promote cell cycle arrest and to inhibit autophagy induced by leflunomide. To explore the mechanisms underlying autophagy induced by DHODH inhibition, we found that AMPK-Ulk1 axis was activated in this process. Besides, JNK was phosphorylated and activated to phosphorylate BCL-2, which abrogated the interaction between BCL-2 and Beclin1 and then abolished autophagy. Our findings provided evidences for the potential of DHODH used as a drug target for melanoma treatment.
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- Rheumatoid disease: an unusual cause of relapsing meningoencephalitis. [Journal Article]
- BCBMJ Case Rep 2018 Jan 12; 2018
- A 73-year-old man presented with three episodes of dysphasia and disinhibited behaviour, a single seizure and transient ischaemic attack-like events characterised by right arm and/or leg weakness. Th...
A 73-year-old man presented with three episodes of dysphasia and disinhibited behaviour, a single seizure and transient ischaemic attack-like events characterised by right arm and/or leg weakness. These episodes were separated by month-long asymptomatic intervals. Medical history included rheumatoid arthritis, which was clinically quiescent on leflunomide.Repeated cerebrospinal fluid examination showed a persistent lymphocytosis with mildly reduced glucose and elevated protein; oligoclonal bands and viral PCR were negative. MRI of the brain was initially normal, but 7 months after initial presentation revealed meningeal enhancement with bifrontal cortical hyperintensities on T2/fluid-attenuated inversion recovery. Brain biopsy demonstrated necrotising granulomatous meningitis with mixed T cell and B cell infiltrates and without evidence of vasculitis or infection. Serum anticyclic citrullinated peptide antibodies were strongly positive.The diagnosis of rheumatoid meningoencephalitis was made on the basis of brain biopsy findings and serological evidence of active rheumatoid disease. Steroids and rituximab therapy were started leading to clinical stabilisation.