Recent progress in the graphene-based biosensing approaches for the detection of Alzheimer's biomarkers.

Alzheimer's disease (AD) is one of the most common types of neurodegenerative disorders. It is possible to identify AD early thanks to the measurement of specific biomarker levels. Owing to crucial roles of biomarkers in the AD, the detection of AD-related biomarkers may be suitable for predictive identification of AD. Biosensors is a novel tool that could be beneficial to appreciate recognition of several AD biomarkers as early as possible. Graphene and its derivatives containing graphene oxide (GO) and reduced-GO (rGO) can be good choice for biosensing approaches due to their unique properties. GO/rGO-based biosensors or nanosensors have been widely used for the determination of AD biomarkers. In this article, the general aspects of AD, its biomarkers, biosensors, and GO are overviewed. In addition, this review provides the current developments in the applications of graphene-based biosensors for recognition of AD biomarkers. Future perspectives and challenges of graphene-based biosensing as a new approach for detection of AD are discussed in brief as well.

Epidemiological Study of Acute Unintentional Poisoning Among Children in Iran.

The occurrence of different types of poisoning and early diagnosis is important for therapeutic measures. In this study, we investigate the epidemiological causes of acute poisoning in children.In this retrospective descriptive study, children presented with acute poisoning during 2010-2019 to Shahid Madani Hospital were included. The Electronic Medical Record system of the hospital was accessed to obtain the data of the patients. The data included was demographic information, type of poisoning, clinical findings, complications, duration of hospitalization, parents' education status, and mortality status.Of 336 patients included in the study, the mean age of patients was 4.90±3.27 years (range: 1-12 years). There was a significant correlation between the age of the child and the type of poisoning, p=0.001. The most frequent age group was 5 years and less (69.6%). The most frequent sex group was male (58.6%). However, there was no significant correlation between the sex of the child and the type of poisoning. Parents' education and ICU admission were also associated significantly with the type of poisoning, p=0.001, respectively. The most common type of poisoning in children was medication (60.6%) which was mainly due to methadone. The mortality rate in the study was 1.2%.Our study showed that pharmacological drugs are the main cause of poisoning in our population. Age of the children is likely to be associated with the type of poisoning however, no gender difference was found in this regard was found in our study.

Factors associated with febrile seizures among children.

OBJECTIVE: Febrile seizures are usually benign and are not presented with neurological manifestation. However, complex febrile seizures are presented with recurrence and might require meticulous management. The aim of this study was to evaluate the demographic, clinical, and laboratory parameters of children with febrile seizures and the correlation between these factors. METHODS: In this retrospective study, children presented with febrile seizure in 2019 presented (XXX) were included. Data based on their history, physical examination, and laboratory tests and discharge recommendations were recorded in a checklist. Data were computerized and statistically analyzed using SPSSv25. RESULTS: Of 77 patients were studied, the mean age of the patients was 29.4 ± 17.6. The mean duration of seizures was 5.09 ± 3.78 min and the mean temperature during seizures was 38.41 ± 0.83 °C. In 44 (57.14%) patients no cause of the fever was recorded. 10 (12.99%) patients had multiple seizures within 24 h 70 (90.91%) seizures ended without medication, and 5 (6.49%) patients were treated with diazepam. The gender of the patients was only correlated with white blood cells, p = 0.014. Other laboratory parameters did not show significant correlation with the gender, p > 0.05. The discharge recommendation was significantly correlated with recurrence within 24 h and type of seizure, p < 0.001, respectively. Lab parameters were significantly associated with family history, p = 0.036 and post-seizure drug, p = 0.005. CONCLUSION: Our study showed that biochemical findings may not be suggestive of febrile seizures and recurrence of seizures and family history is associated with the course of treatment in terms of drugs and imaging.

Frequency of Cardiac Arrhythmias in Children with Cardiological Consulting and Containing Electrocardiogram.

BACKGROUND: Heart diseases are the leading causes of mortality and Congenital Heart Disease (CHD) is the most common birth defect reported worldwide. OBJECTIVE: The aim of this study was to evaluate the incidence of arrhythmias and CHD and the association between the two, among infants and children reported to our center. METHODS: This cross-sectional study included infants and children who were referred to Shahid Madani Hospital, Khorramabad. Electrocardiogram (ECG) was performed in these children to determine the type of arrhythmia and records were used to obtain demographic data and the data regarding CHD. RESULTS: Of 200 children enrolled in the study, 10 children had arrhythmias, 12 had tachycardia, 5 had bradycardia, and 31 had congenital disease. Among children with arrhythmias, 1 had atrial fibrillation, 4 patients had paroxysmal supraventricular tachycardia, 1 person had right bundle branch block, 1 had ventricular tachycardia, 2 had premature ventricular contractions and 1 had junctional ectopic tachycardia. Of the 31 children with CHD, 9 patients were presented with small ventricular septal defect, 4 children had patent foramen ovale, 2 had pulmonary stenosis and 1 of the children had tetralogy of fallout, arterial and ventricular septal defects and transposition of greater arteries, respectively. CONCLUSION: We reported a positive correlation between the arrhythmias and CHD. A larger number of studies collecting focusing on different age groups are therefore required to verify our findings.

Prevalence of Congenital Heart Disease among Children in Khorramabad (West of Iran).

AIMS: Congenital heart disease is among the most common congenital anomalies in pediatrics. The aim of this study was to evaluate the prevalence of congenital heart disease in children in Khorramabad, Iran. METHODS: This is a descriptive-cross sectional study where all the children diagnosed with congenital heart disease by echocardiography were enrolled to the Shahid Madani Hospital. Patient information was collected by means of a questionnaire. Of 1600 children who underwent cardiac counseling, 9.75% presented congenital heart disease. These were most prevalent among the children of 0-28 days of the age (14.7%) and least in children aged 1 month-1 year. According to this study, atrial (20.3%) and ventricular septal defect (10.5%) were the most common heart defects, respectively. Among signs and symptoms of cardiac disease, 49.1% of children had cyanosis, 89.7% with increased CT (cardiothoracic)-ratio, and 82.7% of had heart murmur. Congenital heart disease was more prevalent in male infants (58%) and 6.6% patients had heart failure and 1.4% had other congenital conditions, such as Down syndrome. RESULTS: According to our findings, atrial and ventricular septal defects are the most common congenital heart anomalies, respectively, in pediatric patients in Khorramabad.

Organic Lesions in the Brain MRI of Children with Febrile Seizure.

OBJECTIVE: Seizure is the most common neurological disorders in children, where 4-10% of the cases experience at least one seizure before the age of 16. The most frequent causes of seizures in children are fever, epilepsy, infection and brain damage. The aim of this study was to investigate the frequency of organic lesions in MRI of children with seizures unrelated to fever. MATERIALS AND METHODS: This cross-sectional study included children presented with fever-unrelated seizures. The MRI was examined by a radiologist to identify abnormal findings in each patient. A researcher-made questionnaire including general information, history of head trauma, obstructed labor and the history of seizure was completed for the patients. RESULTS: Of 287 children with fever-related seizure, 127 (45.7%) were male and 151 (54.3%) were female. History of seizure, history of obstructed labor, abnormal MRI, complete delay, use of antiepileptic drug and history of trauma were 22(9.9%), 1 (0.4%), 11(4%), 5(1.8%), 259(93.2%) and 12 (4.3%), respectively. Of 11 patients with abnormal MRI, 4 had MTS lesions, 2 had tumor lesions, 2 had scarring trauma, 1 had an epidural abscess and 1 had meningitis. The frequency of organic lesions had no significant differences based on gender, use of antiepileptic drug and traumatic history, but it had a significant relation with obstructed labor andthehistory of seizure. CONCLUSION: The results showed that organic brain lesions in children with fever-unrelated seizure had a significant relationship with the history of seizure and obstructed maternal labor.

Clinical Manifestations and Therapeutic Findings of the Children with Glucose-6-Phosphate Dehydrogenase Deficiency Presenting Favism.

AIM: Favism is characterized as acute anemia, due to Glucose-6-phosphate dehydrogenase (G6PD) deficiency as a result of fava beans intake. It is associated with paleness, jaundice, and hemoglobinuria. In this study, signs, symptoms and therapeutic findings of the patients with hemolysis due to G6PD deficiency were investigated in Shahid Madani Hospital of Khorramabad, Lorestan. METHODS: This is a single-center cross-sectional descriptive study that was conducted on all children with G6PD deficiency-induced hemolysis. RESULTS: 308 children (64.3% male and 35.7% female) were included in this study. The most common complaint was jaundice (82.5%) and the most common cause of hemolysis was the intake of fava bean (85.7%). 68% of the children were treated with hydration/fluid therapy. Blood transfusion was conducted in 36.36% of the cases and the mean of blood administered was 18.9 cc/kg. CONCLUSION: In this study, hydration therapy was performed in most of the children presenting favism. Also, the incorrect calculation of the amount of blood needed for transfusion increased the frequency of blood transfusions and prolonged hospitalization time.

Congenital Heart Disease in Non-Diabetic Large-for-Gestational-Age (LGA) Neonates.

BACKGROUND: Congenital heart diseases are the most prevalent congenital abnormalities in the neonates, caused by environmental and genetic factors and contributing to the leading cause of death. This study aims to evaluate the relationship between neonates with large for gestational age and increased risk of congenital heart diseases among non-diabetic mothers. METHODS: In this study, 179 neonates with large gestational age in Khorramabad were enrolled where heart abnormalities were evaluated using echocardiography. RESULTS: 87 neonates had more than 4000 g of birth weight with no heart abnormalities and 92 (51%) macrosomic neonates had congenital heart diseases. Statistical analysis revealed a significant relationship between birth weight and increased risk of acquiring congenital heart disease between the two groups. There was no significant relationship between birth weight, maternal age, gender, labor type and blood group between the two groups. The highest incidence of congenital heart anomalies was related to 38% of arterial septal defect (ASD) and 15.2% of ASD and VSD, respectively. CONCLUSION: The most prevalent abnormality was arterial septal ASD. None of these abnormalities were associated with maternal age, birth weight and neonate gender. Future studies for congenital heart disease and neonatal birth weight are, therefore, recommended.

Evaluation of Ischemic Heart Disease Factors in Hemophilia Patients in Khorramabad.

BACKGROUND: Evaluation of risk factors associated with coronary artery disease and cardiac health in hemophilia patients is necessary to prevent the onset of ischemic heart disease. In this study, we evaluated the cardiovascular status of hemophilic patients in Lorestan province for the early onset of ischemic heart disease. METHODS: In this cross-sectional descriptive study, a total of 80 patients presenting severe hemophilia, a detailed questionnaire-based investigation was conducted to analyze the prevalence of cardiovascular risk factors in severe hemophilic patients. In patients with hemophilia, body mass index (BMI), blood pressure, diabetes, LDL, cholesterol and HDL, the risk of cardiovascular death was estimated using a predictive risk predictor algorithm of Europe SCORE. RESULTS: The mean age of the patients was 25 years, where all the patients were non-diabetic. Echocardiography did not show any wall motion abnormality and changes in the T wave and dysrhythmia were also not seen by ECG. 7 patients had high blood pressure, 11 had abnormal HDL, and 1 had abnormal LDL. In this study, serum LDL and HDL levels were not significantly correlated with age and BMI. Conversely, age and BMI were significantly associated with hypertension. Hypertension was observed in people over the age of 25 years and in overweighed individuals. 78.8% had normal BMI and 21.3% were overweighed. There was no significant correlation between serum LDL, serum HDL, and blood pressure and sex. The levels of abnormal LDL and HDL were higher in men than in women. CONCLUSION: ECG findings from our study did not report any significant cardiac abnormalities among hemophilic patients. Cardiovascular risk factors were not significantly correlated in these patients.

Effect of Phototherapy on Stroke Volume in Newborn Infants with Jaundice.

One of the rare complications associated with phototherapy include redistribution of blood flow that can alter cardiac output in infants. The aim of this study was to evaluate the effects of phototherapy on left ejection fraction in infants with jaundice. Twenty-nine infants admitted in Shahid Madani Children Hospital for receiving phototherapy were included in this study. Echocardiography was performed in the participants, immediately before and 24 hours after the treatment. Nineteen infants were reported to have decrease in the stroke volume following the treatment. The mean levels of stroke volume before and after phototherapy were 6.99 ± 2.17 and 6.55 ± 1.85 L/m 2 , respectively ( p = 0.011). Phototherapy can reduce left ejection fraction in newborn infants with hyperbilirubinemia.

Evaluating the Usefulness of Lab-Based Test for the Diagnosis of Pneumonia in Children.

OBJECTIVE: The aim of this study is to determine the distribution of the results of routine laboratory tests for the diagnosis of pneumonia in children in Khorramabad. METHODS: This is a cross-sectional study and was performed on 650 children with pneumonia who were referred to Shahid Madani Hospital. From patients' test results, the following data were recorded: whether the results were normal or not, age, sex, serotype, history of diabetes mellitus, and the presence of urinary and digestive tract symptoms. RESULTS: There was no difference in the prevalence of pneumonia, gender-wise, whereas 40% of the patients were under 2 years. In addition, 53.7% of the patients were presented with leukocytosis. From the blood test, blood urea nitrogen, creatinine, sodium, and potassium were normal in most of the patients. Stool examination, urine analysis, urine culture, erythrocyte sedimentation rate, C-reactive protein, and blood sugar were also normal in these patients. CONCLUSION: Children under the age of 2 years are more susceptible to lung infections. Findings from blood tests such as leukocytosis are useful for making initial diagnosis other than computed tomography scan. Other lab tests might not give any useful results. In addition, a closer examination of the urinary system and digestive tract involvement is recommended, prior to urine or stool analysis.

Evaluation of α-klotho level in insulin dependent diabetes mellitus (IDDM) children.

Objectives Reduced levels of α-Klotho is associated with the pathogenesis of various diseases including diabetes. In type I diabetes, decrease in Klotho leads to apoptosis of ß-cells of pancreases. The aim of this study was to evaluate the levels of α-Klotho in type I diabetic pediatric patients. Methods In this cross-sectional single centered study, 46 patients presenting type I diabetes mellitus (case group) and 78 control group under the age of 12, referred to our clinic were included in our study. Serum levels of soluble Klotho were measured by sandwich ELISA in case and control groups. Statistical analysis was conducted for the data recorded via questionnaire. Results Mean age of the patients in the case and control group was 7.65 ± 3.09 and 7 ± 2.37, respectively. Type I diabetes patients had a significant reduction in the levels of serum Klotho, as compared to controls (p<0.001). However, gender and age-based comparison between patient and control group was not significant. Conclusions This study reports a significant decrease in the serum levels of α-Klotho in type 1 diabetic patients. Low levels of Klotho can be associated with diabetic nephropathy and other comorbidities in these patients.

The protective effect of fasudil against acrylamide-induced cytotoxicity in PC12 cells.

Acrylamide (ACR), a vinyl monomer that has multiple chemical and industrial applications, is a neurotoxic agent in human and animal. Fasudil is a potent Rho-kinase inhibitor which exhibits neuroprotective effects in some neuronal degenerative disorders. In this study, the potential protective effect of Fasudil on ACR-induced cytotoxicity in PC12 cells was evaluated. Our results showed that ACR increased the level of intracellular reactive oxygen species (ROS) and consequently upregulated the Bax/Bcl-2 ratio and significantly elevated the level of caspase-3 and 9 proteins in PC12 cells. Interestingly, pretreatment with Fasudil protected PC12 cells against ACR-induced toxicity mainly through the reduction of ROS production and modulation of proteins which involved in apoptosis pathway. Fasudil down-regulated the Bax/Bcl-2 ratio and the levels of caspase-3 and 9 proteins in cells exposed to ACR. In conclusion, the neuroprotective effect of Fasudil against ACR-induced toxicity in PC12 cells appears to be mediated through inhibition of ROS production and modulation of apoptosis.

Pharmacokinetic changes of tramadol in rats with hepatotoxicity induced by ethanol and acetaminophen in perfused rat liver model.

Tramadol is an opioid agonist with activation monoaminergic properties. It can be administered orally, rectally, intravenously, or intramuscularly as a centrally acting analgesic. Liver injury can lead to changes in the metabolism of tramadol. In this study, the rate of tramadol metabolism in rats with damaged liver induced by ethanol and acetaminophen was assessed in a recirculation perfusion system. Acetaminophen is a mild analgesic and antipyretic agent, which can cause centrilobular hepatic necrosis in toxic doses, whereas alcohol causes death due to liver diseases. Alcoholic liver disease (ALD), such as alcoholic fatty liver, alcoholic hepatitis, and alcoholic fibrosis, is the most common liver disease. The aim of this study was to investigate the alteration in tramadol metabolism in different hepatotoxicity conditions in animal models. Male rats were randomly assigned to three groups. The control group received normal saline, group 2 received acetaminophen at the dose of 250 mg/kg/day, and group 3 received ethanol at the beginning dose of 3 g/kg/day, which was slowly increased to 6 g/kg/day. Tramadol was added to the perfusion solution at the concentration of 500 ng/mL. Samples were collected during 180 min, and analyte concentrations were determined by the High-Performance Liquid Chromatography (HPLC) method. The concentration of tramadol and its three main metabolites, O-desmethyltramadol (M1), N-desmethyltramadol (M2), and N,O-didesmethyltramadol (M5), were determined in perfusate samples. Ethanol and acetaminophen significantly affected the pattern of weight gain and liver weights before perfusion and caused a significant increase in enzyme activities. Moreover, histopathologic examination revealed that ethanol and acetaminophen caused liver damage. An increase in the elimination half-life and reduced clearance rate of tramadol were seen in the acetaminophen and ethanol groups, in comparison to the control group. Additionally, significant reductions in the Area Under the Curve (AUC) of metabolites of tramadol (M1, M2, and M5) were observed in the acetaminophen and ethanol groups in the perfused rat liver model. Liver damage caused by ethanol and acetaminophen during 45 days in animals leads to a significant reduction in the level of tramadol metabolites. Therefore, in patients with liver damage caused by ethanol and acetaminophen, caution needs to be considered when prescribing tramadol.

Protective effect of lycopene against chemical and natural toxins: A review.

People are exposed to a number of environmental, occupational, and therapeutic toxic agents which may be natural or man made. These hazardous substances may manifest as direct side effects on the function of organs or indirectly induced alteration of gene expression, cancer-associated metabolic pathways, and/or alter homeostasis. Lycopene, as a one of the most potent antioxidant, is found in fruits and vegetables. High-intake of lycopene has been shown to be effective in decreasing the risk of both natural toxins including mycotoxins, bacterial toxins, and chemical toxins including heavy metals, pesticides as well as herbicides. Recently, there is growing attention in understanding the mechanisms of the phytochemicals and carotenoids as antioxidative, antiapoptotic, radical scavenging, and chelating agents and their roles in the modulation of inflammatory pathways. This review summarizes available data from several recent studies about lycopene and its role against chemical and natural toxicants. © 2018 BioFactors, 45(1):5-23, 2019.

Predictors of Long-term Major Adverse Cardiac Events Following Percutaneous Coronary Intervention in the Elderly.

BACKGROUND: We aimed to recognize the predictors of long-term major adverse cardiac events (MACE) in the elderly candidates for elective percutaneous coronary intervention (PCI) at our center. METHODS: In this retrospective cohort study, we reviewed the data of the elderly (age ≥65 years) candidates for elective PCI who met our study criteria, at Tehran heart center between 2004 and 2013. Demographic, anthropometric, clinical, angiographic, procedural and follow-up data of the enrolled patients were retrieved from the angiography/PCI databank of our center. The study characteristics of the patients with or without MACE were compared in a univariable Cox-regression analysis. A multivariable Cox-regression model was applied using variables selected from the univariable model to determine the predictors of MACE. RESULTS: We reviewed the data of 2772 patients (mean age=70.8±4.7 years, male sex=1726 patients [62.3%]) from which 393 patients (14.4%) developed MACE. In the multivariable regression model, female sex was a protective factor for MACE (hazard ratio [HR]=0.701; P=0.001), while presence of diabetes mellitus (HR=1.333; P=0.007), family history of coronary artery disease (CAD) (HR=1.489; P=0.003) and plain balloon angioplasty (HR=1.810; P=0.010) were independent risk factors for MACE. CONCLUSION: PCI is a safe and effective method of revascularization in the elderly patients, and some clinical and procedural factors can predict MACE in this group of patients.

Nanomaterial-based biosensors and immunosensors for quantitative determination of cardiac troponins.

Cardiovascular diseases (CVDs) are the most frequent mortality cause in many countries. The acute myocardial infraction (AMI) is one of the most common types of CVDs. Cardiac troponin I (cTnI) and cardiac troponin T (cTnT) as predominant cardiac infarction biomarkers considered as "gold standard" for diagnosis of acute myocardial infraction (AMI). The restrictions of traditional methods have encouraged the development of highly sensitive and specific methods for cTnI and cTnT detection. The rapid, early, reliable, and cost-effective diagnosis of CVDs not only helps with patient survival, but also save cost and time to prosperous prognosis. In recent years, the concept of biosensors has opened new horizons in high precision detection. Once combined with nanomaterials, nano-scale biosensors provide powerful analytical platforms for diagnosing of cTnI and cTnT. In this article, after a brief overview of the cardiac troponins, a classification and description of the research progresses of biosensors and immunosensors for the detection and quantitative determination of cardiac troponins based on optical and electrochemical platforms are presented.

Label-free nano-biosensing on the road to tuberculosis detection.

Tuberculosis, an ailment caused by the bacterium Mycobacterium tuberculosis (Mtb) complex, is one of the catastrophic transmittable diseases that affect human. Reports published by WHO indicate that in 2017 about 6.3 million people progressed to TB and 53 million TB patients died from 2000 to 2016. Therefore, early diagnosis of the disease is of great importance for global health care programs. Common diagnostics like the traditional PPD test and antibody-assisted assays suffer the lack of sensitivity, long processing time and cumbersome post-test proceedings. These shortcomings restrict their use and encourage innovations in TB diagnostics. In recent years, the biosensor concept opened up new horizons in sensitive and fast detection of the disease, reducing the interval time between sampling and diagnostic result. Among new diagnostics, label-free nano-biosensors are highly promising for sensitive and accessible detection of tuberculosis. Various specific label-free nano-biosensors have been recently reported detecting the whole cell of M. tuberculosis, mycobacterial proteins and IFN-γ as crucial markers in early diagnosis of TB. This article provides a focused overview on nanomaterial-based label-free biosensors for tuberculosis detection.

Aptamer-based biosensors and nanosensors for the detection of vascular endothelial growth factor (VEGF): A review.

Vascular endothelial growth factor (VEGF) is a key regulator of vascular formation and a predominant protein biomarker in cancer angiogenesis. Owing to its crucial roles in the cancer metastasis, VEGF detection and quantification is of great importance in clinical diagnostics. Today, there exist a wide variety of detection strategies for identifying many types of disease biomarkers, especially for VEGF. As artificial single-stranded DNA or RNA oligonucleotides with catalytic and receptor properties, aptamers have drawn lots of attention to be applied in biosensing platforms due to their target-induced conformational changes as well as high stability and target versatility. So far, various sensitivity-enhancement techniques in combination with a broad range of smart nanomaterials have integrated into the design of novel aptasensors to improve detection limit and sensitivity of analyte detection. This review article provides a brief classification and description of the research progresses of aptamer-based biosensors and nanobiosensors for the detection and quantitative determination of VEGF based on optical and electrochemical platforms.

Simultaneous measurement of formic acid, methanol and ethanol in vitreous and blood samples of postmortem by headspace GC-FID.

BACKGROUND: Formic acid (formate) is the main reason for toxicity and death through methanol poisoning. The simultaneous determination of methanol, ethanol, and formate in the body can help to discover the cause of death and is useful in the diagnosis of acute methanol poisoning. The measurement of formate is not yet available in Iran. With regard to the increasing rate of methanol poisoning and its related mortality in Iran, as well as the main role of formate in methanol poisoning, this study was designed to set up an analytical method for the concurrent determination of ethanol, methanol, and formate. METHODS: Following the modification of a previously developed gas chromatography method, vitreous and blood samples of 43 postmortem cases with a history of methanol intoxication were collected over a period of 2 years at the Legal Medicine Organization of Mashhad. Thereafter, ethanol, methanol, and formate concentrations were measured by headspace GC/FID. Formate esterification was performed by the methylation of formate with sulfuric acid and methanol. In order to confirm the esterification method for the production of methyl formate, we used gas chromatography with a mass detector (GC/MS) because of its higher sensitivity and accuracy. Furthermore, the correlations between formate and methanol concentrations in blood and vitreous samples, and between formate and methanol were investigated. RESULTS: A significant relationship was found only between methanol concentrations in blood and vitreous samples (P < 0.03). CONCLUSIONS: In postmortems, with the passage of time since alcohol ingestion, the measurement of only methanol concentration cannot determine the degree of toxicity or the cause of death. Therefore, using the present analytical method and measurement of formic acid, we can estimate the degree of toxicity and cause of death.