Acute and delayed toxicity from co-ingestion of methylene chloride and methanol

Biodegradable biopolymers: Real impact to environment pollution

Biobased biodegradable polymers (BBP) derived from different renewable resources are commonly considered as attractive alternative to petroleum-based polymers, such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), etc. It is because they can address the issues of serious environmental problems resulted from accumulation of plastic wastes. In the review current methods of obtaining of most abundant BBP, polylactic acid (PLA) and polyhydroxybutyrate (PHB), have been studied with an emphasis on the toxicity of compounds used for their production and additives improving consumer characteristics of PLA and PHB based market products. Substantial part of additives was the same used for traditional polymers. Analysis of the data on the response of different organisms and plants on exposure to these materials and their degradation products confirmed the doubts about real safety of BBP. Studies of safer additives are scarce and are of vital importance. Meanwhile, technologies of recycling of traditional petroleum-based polymers were shown to be well-developed, which cannot be said about PLA or PHB based polymers, and their blends with petroleum-based polymers. Therefore, development of more environmentally friendly components and sustainable technologies of production are necessary before following market expansion of biobased biodegradable products.

A rare combination of methemoglobinemia and carboxyhemoglobinemia in pesticide poisoning

Dyshemoglobinemias are disorders in which the haemoglobin is functionally altered and prevented from carrying oxygen. They include carboxyhemoglobin, methemoglobin, and sulfhemoglobin. This increase in abnormal haemoglobin has reduced oxygen binding capacity, which leads to decrease in total oxygen content in the blood causing anaemic-hypoxia. The anaemic-hypoxia which is present in these disorders are refractory to the oxygen supplementation and cause many systemic and life threatening complications.Many cases are reported in literature with either of haemoglobin. It is very rare to have two abnormal haemoglobin levels in the same patient. Here we discuss an uncommon case which presented to our tertiary care hospital after consuming pesticide with suicidal intention. The patient was very pale, had peripheral cyanosis,tachypnea and tachycardia and dizziness on presentation. The SpO2 of 85% was our clue to suspect methemoglobinemia which was confirmed along with carboxyhemoglobinemia on arterial blood gas saving result. Despite that patient being very unstable, she was successfully managed with 100% oxygen through High flow nasal cannula (HFNC), methylene blue and blood transfusion. The patient's signs and symptoms gradually reduced in a few days and got discharged after 2 weeks without any neurological and cardiorespiratory sequelae. An early suspicion and personalized emergency management was the key to success. As in all fields of Medicine, Emergency Medicine is also witnessing a change towards precision and personalized Medicine practice.

Dichloromethane increases mutagenic DNA damage and transformation ability in cholangiocytes and enhances metastatic potential in cholangiocarcinoma cell lines

Dichloromethane (DCM), a widely used chlorinated solvent, is classified by IARC (2017) as probably carcinogenic to humans. Exposure to DCM has been associated with increased incidence of cholangiocarcinoma (CCA) in humans. This study aimed to investigate how DCM could contribute to CCA development by investigating the effects of DCM on DNA damage and cell transformation in cholangiocytes (MMNK-1) and on metastatic potential as measured by invasion and cell migration in malignant CCA cell lines (HuCCA-1 and RMCCA-1). MMNK-1 cells treated with the non-cytotoxic concentration of DCM (25 μM, 24 h) significantly increased the levels of mutagenic DNA adducts including 8-hydroxydeoxyguanosine, 8-OHdG, (1.84-fold, p < 0.01) and 8-nitroguanine (1.96-fold, p < 0.01) and enhanced cell transformation by 1.47-fold (p < 0.01). In addition, the expression of various genes involved in carcinogenesis, namely, NFE2L2 (antioxidative response), CXCL8 (inflammation), CDH1 (cell adhesion), MMP9 (tissue remodeling) and MKI67 (cell proliferation) were altered in cholangiocytes treated with DCM. When MMNK-1 cells were transformed by DCM, the expression of all the aforementioned genes was also increased. In malignant cell lines (HuCCA-1 and RMCCA-1), DCM treatment resulted in increased CXCL8 and MMP9 transcription and decreased CDH1 transcription accompanied by increased invasion and migration capabilities of these cells. Taken together, this study demonstrated that DCM exposure could be linked to the development of CCA.