A mass event of paraquat poisoning via inhalation

Objective

In January 2023, a rare event of collective inhalation paraquat poisoning occurred in Shandong, China. To analyze the clinical characteristics of an event of respiratory tract paraquat poisoning through inhalation.

Methods

Clinical data from eight patients with paraquat inhalation poisoning were retrospectively analyzed.

Results

The patients were mainly exposed to paraquat via the respiratory tract. The main clinical manifestations were ocular and respiratory irritation. Lung computed tomography (CT) showed that all eight patients had varying degrees of lung injury, mainly manifesting as exudative lesions. Laboratory tests revealed arterial blood gas hypoxemia, abnormal white blood cell count, and increased neutrophil ratio. Sufficient glucocorticoid impact therapy was effective, and all eight patients survived.

Conclusion

Eight patients experienced chest tightness, shortness of breath, and varying degrees of lung injury due to inhalation of paraquat through the respiratory tract. The early use of glucocorticoids and other comprehensive treatment measures, active prevention and treatment of lung infections, and protection of organ function have beneficial effects in such cases.

Study on the therapeutic effect of glucocorticoids on acute kidney injury in rats exposed to diquat

AIMS

To preliminarily explore, whether glucocorticoids have a therapeutic effect on diquat-induced acute kidney injury in rats.

METHOD

150 Wistar rats were randomly divided into six groups: exposure model group (DQ group), dexamethasone control group (GC group), blank control group (Ctrl group), dexamethasone 2.1 mg/kg dose group (DQ+L-GC group), dexamethasone 4.2 mg/kg dose group (DQ+M-GC group), and dexamethasone 8.4 mg/kg dose group (DQ+H-GC group), with 25 rats in each group. Each group was further divided into five subgroups, 24 h, 3 d, 7 d, 14 d, and 21 d after exposure, according to the feeding time and the course of treatment, with five animals in each subgroup. The rats in DQ, DQ+L-GC, DQ+M-GC, and DQ+H-GC groups were administered 115.5 mg/kg diquat by gavage, respectively. Moreover, 30 min after gavage, rats in DQ+L-GC group, DQ+M-GC group, DQ+H-GC group and GC group were intragastric administered dexamethasone 2.1 mg/kg, 4.2 mg/kg, 8.4 mg/kg and 8.4 mg/kg, respectively. After 7 days, the intraperitoneal injection of dexamethasone was changed to 6.3 mg/kg prednisone by intragastric administration. Subsequently, 7 days later, it was changed to 3.15 mg/kg prednisone by intragastric administration until the end of the experiment on 21 days. After the start of the experiment, changes in the conditions of the rats in each group were observed at a fixed time every day, changes in the body weight of the rats were monitored at the same time, and the death of the rats was recorded at 24 h, 3 d, 7 d, 14 d, and 21 d after exposure. The rats were sacrificed by an intraperitoneal injection of 100 mg/kg sodium pentobarbital overdose. Blood was collected by puncture of the inferior vena cava, used to determine Cr and BUN. The upper segment of the left kidney was collected for histopathological examination. Elisa was used to detect neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) in the lower segment of left kidney. TLR4, Myd88, and NF-κB were detected in the right kidney.

RESULTS

(1) After exposure, most rats in DQ group, DQ+L-GC group, DQ+M-GC group and DQ+H-GC group showed shortness of breath, oliguria, diarrhea, yellow hair and other symptoms. No symptoms and related signs were observed in Ctrl group and GC group. (2) The weight of rats in the Ctrl group and the GC group increased slowly during the test. the body weight of the rats in the DQ, DQ+L-GC, DQ+M-GC, and DQ+H-GC groups continued to decrease after self-infection. Body weight dropped to the lowest point at approximately 7 d, and gradually increased from 7 d to 21 d. (3) A small amount of capillary congestion in the medulla was observed after 7 days in the GC group. The DQ group showed tubular atrophy, edema of the epithelial cells, and over time, the tubules were seen dilated and became irregular in shape; large amount of capillary congestion was also observed in the renal cortex and medulla. The renal injury in the DQ+L-GC group was less than that in the DQ group. DQ+H-GC group had no obvious injury before 7 d, but more renal tubules were seen in the DQ+H-GC group from 7 d to 14 d. (4) Compared with the DQ group, there was no difference before 14 d, and at 14 d-21 d, DQ+L-GC group, DQ+M-GC group, DQ+H-GC group all had different degrees of decline. NGAL content: Compared with the DQ group, the content of NGAL and KIM-1 in kidney tissue of the DQ+L-GC, DQ+M-GC, and DQ+H-GC groups decreased compared with the DQ group at each time node. (5) Compared with the Ctrl group, the expression of TNF-α, TLR4, MyD88, NF-κB in the DQ, DQ+L-GC, DQ+M-GC, and DQ+H-GC groups at each time node increased in the renal tissue. The content of TNF-α, TLR4, MyD88, NF-κB in kidney tissue of the DQ+L-GC, DQ+M-GC, and DQ+H-GC groups at each time node was lower than that in the DQ group.

CONCLUSION

(1) Diquat can cause kidney damage in rats, mainly manifested as renal tubular atrophy, epithelial cell edema, capillary congestion and dilation, and the renal function damage indicators have been improved to varying degrees. (2) Glucocorticoids have therapeutic effects on acute kidney injury in rats exposed to diquat. During the treatment, the efficacy of glucocorticoids did not increase with increasing doses after reaching a dose of 4.2 mg/kg. (3) TLR4 receptor-mediated TLR4/Myd88/NF-κB signaling pathway is involved in the inflammatory response of acute kidney injury in diquat poisoning rats. Glucocorticoids can inhibit the inflammatory response, thereby affecting the expression of TLR4/Myd88/NF-κB signaling pathway-related proteins.

Case report: Reversible splenial lesion syndrome caused by diquat poisoning

Diquat (DQ), chemically known as 1,1 '-ethylene-2,2' -bipyridine, is a non-selective herbicide for leaf removal and drying. It has toxic effects on central nervous system cells, and toxic neurological lesions include axonal degeneration and pontine myelolysis. At the same time, DQ can also affect the activity of dopaminergic nerve cells through oxidative stress, causing degeneration and reducing dopamine uptake. With the increasing application of DQ in agricultural production, the clinical reports of neurotoxicity caused by acute DQ poisoning are also increasing. At present, DQ rapid-phase-related toxic encephalopathy mainly involves the pons, midbrain, basal ganglia, thalamus and other brain regions. However, this case is unusual in that the lesion mainly involved the splenium of the corpus callosum. It is also the first time to be reported.

Multiorgan failure caused by Chinese herbal medicine Xanthii Fructus poisoning: a case report

BACKGROUND

Xanthii Fructus was used in the treatment of rhinitis and related nasal disease. It is the most commonly used chemically active component in compounds formulated for the treatment of rhinitis. However, poisoning, resulting in serious consequences, can easily occur owing to cocklebur overdose, improper processing, or usage without processing.

CASE PRESENTATION

We reported on a 55-year-old man who experienced allergic rhinitis for 2.5 years. He ingested unprocessed Xanthii Fructus for 2 months as treatment. However, he developed anorexia; nausea; abdominal pain; general weakness; hiccups; oliguria and anuria; significantly elevated serum alanine aminotransferase, aspartate aminotransferase, and creatinine levels; and abnormalities in blood coagulation series. Nutritional support; daily drugs for liver protection, gastric protection, inflammation reduction; fresh plasma; and cryoprecipitate infusion were administered. Continuous venovenous hemodialysis (Prismaflex ST100) was also administered. However, the patient's multiple organ failure gradually worsened, ultimately leading to death.

CONCLUSION

Xanthii Fructus poisoning affects multiple systems, and its clinical manifestations are complex. Therefore, it is easily misdiagnosed and missed. Along with careful inquiry of medical and medication history, early diagnosis and intervention are vital for a successful treatment. It is also important to educate people and create awareness about this poisoning. Therefore, this intractable case has great clinical significance.

[Study of the urban-impact on microbial communities and their virulence factors and antibiotic resistance genomes in the Nandu River, Haikou]

Objective: To explore the changes in bacterial community structure, antibiotic resistance genome, and pathogen virulence genome in river water before and after the river flowing through Haikou City and their transmission and dispersal patterns and to reveal anthropogenic disturbance's effects on microorganisms and resistance genes in the aquatic environment. Methods: The Nandu River was divided into three study areas: the front, middle and rear sections from the upstream before it flowed through Haikou City to the estuary. Three sampling sites were selected in each area, and six copies of the sample were collected in parallel at each site and mixed for 3 L per sample. Microbial community structure, antibiotic resistance, virulence factors, and mobile genetic elements were analyzed through bioinformatic data obtained by metagenomic sequencing and full-length sequencing of 16S rRNA genes. Variations in the distribution of bacterial communities between samples and correlation of transmission patterns were analyzed by principal co-ordinates analysis, procrustes analysis, and Mantel test. Results: As the river flowed through Haikou City, microbes' alpha diversity gradually decreased. Among them, Proteobacteria dominates in the bacterial community in the front, middle, and rear sections, and the relative abundance of Proteobacteria in the middle and rear sections was higher than that in the front segment. The diversity and abundance of antibiotic resistance genes, virulence factors, and mobile genetic elements were all at low levels in the front section and all increased significantly after flow through Haikou City. At the same time, horizontal transmission mediated by mobile genetic elements played a more significant role in the spread of antibiotic-resistance genes and virulence factors. Conclusions: Urbanization significantly impacts river bacteria and the resistance genes, virulence factors, and mobile genetic elements they carry. The Nandu River in Haikou flows through the city, receiving antibiotic-resistant and pathogen-associated bacteria excreted by the population. In contrast, antibiotic-resistant genes and virulence factors are enriched in bacteria, which indicates a threat to environmental health and public health. Comparison of river microbiomes and antibiotic resistance genomes before and after flow through cities is a valuable early warning indicator for monitoring the spread of antibiotic resistance.

Current situation and influencing factors for suicidal intent in patients with intentional acute pesticide poisoning

Introduction

Since pesticides have been widely used in agricultural production, acute pesticide poisoning (APP) has gradually become a worldwide public health problem. Recently, the number of APP cases has been high in China, and the intentional self-administration of pesticides is the main cause of APP. However, there is a lack of relevant studies on the factors influencing suicidal intent in patients with intentional APP. This study aimed to explore the current situation and influencing factors for suicidal intent among patients with intentional APP.

Methods

In this cross-sectional study, we enrolled a total of 225 patients with intentional APP admitted to the emergency department of our Grade A comprehensive hospital in Shandong Province between June 2019 and January 2021. Patients were investigated using a health status interview questionnaire, Beck Suicidal Intent Scale, Duke Social Support Index, psychological stress scale, Dickman Impulsivity Inventory, Trait Anxiety Inventory, Center for Epidemiologic Studies Depression Scale, and Beck Hopelessness Scale. Descriptive statistics, single-factor analysis, and multiple linear regression were used for data analysis.

Results

Suicidal intent scores were collected and averaged (14.23 ± 6.22). Multiple linear regression analysis revealed that marital status, residential area, impulsivity, hopelessness, depression, psychological strain, and social support impact suicidal intent.

Conclusion

Patients with intentional APP have high suicidal intent. Therefore, different interventions should be tailored to different patients.

Case Report: Acute Intoxication from Phosphine Inhalation

Aluminum phosphide is a highly effective insecticide for fumigation in granaries and is often used in rural grain storage. However, people's awareness of its toxicity is not strong. A case of acute inhalation toxicity of phosphine caused by the use of aluminum phosphide to fumigate a granary is reported here. The case presented with aspiration pneumonia and acute left heart failure. The patient was cured using comprehensive life support treatment, including respiratory support, antiarrhythmic treatment, and blood pressure maintenance with vasoactive drugs. There is no specific antidote for phosphine poisoning at present, and the comprehensive application of restricted fluid resuscitation, high-dose glucocorticoid shock, vasoactive drugs and bedside hemofiltration is significant in improving the prognosis of patients. It is also important to remind people to pay attention to their own protection in the process of using aluminum phosphide.

[Epidemiological characteristics of typhus in China, 1950-2021]

Objective: To analyze the epidemiological characteristics of typhus in China from 1950 to 2021, and discuss the challenges in typhus prevention and control in China and suggest future prevention and control strategies. Methods: Based on the reported data of typhus from 1950 to 2021 in China from the Infectious Disease History Database of China Public Health Science Data Center and the National Notifiable Infectious Disease Reporting Information System of Chinese Center for Disease Control and Prevention, we conducted a descriptive statistical analysis. Mann-Kendall test and circular distribution method were used to analyze the incidence, mortality and case fatality of typhus to reveal the temporal, spatial and population distributions and diagnosis of typhus in China. Results: From 1950 to 2021, a total of 452 965 typhus cases and 7 339 typhus deaths were reported in China, with the cases numbers exceeding 10 000 in 14 years of the 1950s, 1960s and 1980s, respectively. Since 1990s, the reported cases and incidence rate of typhus have decreased dramatically and the most cases were sporadic. However, the reported typhus cases in Anhui, Hubei, Hunan Provinces showed significant uptrends. Although typhus could occur all the year round, but the seasonality was observed with the incidence mainly in summer and autumn. For different provinces from the north to the south, the peaks of typhus' monthly incidence tended to shift to earlier dates. The male to female ratio of the cases was 1.01∶1 (18 529∶18 366). However, more cases occurred in women in recent years. The cases aged ≤9 years accounted for the highest proportion (18.9%), but the number of cases aged ≥50 years showed an upward trend. Most cases were farmers with the proportion increasing year by year. Moreover, the cases in students and scattered-living children also accounted for relatively higher proportions. The median of the interval between onset and diagnosis of typhus was 6 days. Most cases were clinically diagnosed, while the proportion of laboratory-confirmed cases was low and most laboratory cases were confirmed by Well-Felix reaction. Conclusions: Although the incidence and mortality of typhus in China has decreased significantly, the risk for local typhus outbreaks still exists. The prevention and control of typhus still face many challenges. It is indispensable to strengthen the pathogen detection and surveillance for typhus in China.

[Establishment and evaluation of a method for phages enrichment by ferric trichloride-polyvinylidene fluoride membrane filter]

Objective: To establish and evaluate a method of enriching bacteriophages in natural water based on ferric trichloride-polyvinylidene fluoride (FeCl₃-PVDF)membrane filter. Methods: Based on the principle of flocculation concentration, the method of recovering bacteriophage from water sample was established by using iron ion flocculation combined with membrane filter. The titer of phage was determined by Agar double layer method. The recovery efficiency of phage was detected by phage fluorescence staining and real-time fluorescence PCR reaction. Water samples from different sources were collected for simulation experiment to evaluate the enrichment effect. At the same time, the sewage discharged from hospitals was taken as the actual water sample, and the common clinical drug-resistant bacteria were used as the host indicator bacteria to further analyze the enrichment effect of FeCl₃-PVDF membrane filter rapid enrichment method on the bacteriophage in natural water samples. Results: The method of enrichment of bacteriophages in natural water by iron ion concentration 50 mg/L and PVDF membrane filter was established. The recovery rate of this method for bacteriophage was 93%-100%. Under the multi-functional microscope, it was found that the bacteriophage of the enriched water sample increased significantly and the fluorescence value of the enriched water sample determined by the enzyme labeling instrument was about 13 times as high as that before enrichment. After concentration of the actual water samples from the hospital drainage, the positive rate of bacteriophage isolation in the concentrated group and the non-concentrated group was 23% and 4%, and the fluorescence value in the concentrated group was 2-24 times as high as that of the non-concentrated group. Conclusion: The method of FeCl₃-PVDF membrane filter is a simple, efficient and rapid method for enriching bacteriophages in different water samples.

[Drug resistance and genomic characteristics of a strain of O139 Vibrio cholerae isolated from human bloodstream infection]

Objective: To analyze the drug resistance and genomic characteristics of a strain of serogroup O139 Vibrio cholerae producing cholera toxin isolated from the bloodstream of a person with bacteremia. Methods: The broth dilution method and automatic drug sensitivity analyzer were used to determine the antibiotic sensitivity of the strain. The complete genome sequence of the strain was obtained by using second-generation gene sequencing and nanopore sequencing. BLAST software was used for comparison and analysis with CARD, Resfinder, ISfinder, VFDB, and other databases. The drug-resistant genes, insertion sequences and virulence genes carried by the strain were identified. MEGA 5.1 software was used to construct a genetic phylogenetic tree based on the core genomic single nucleotide polymorphisms. Results: V. cholerae SH400, as the toxigenic strain, carried multiple virulence-related genes and four virulence islands. The strain was resistant to streptomycin, tetracycline and cotrimoxazole, carrying corresponding drug-resistant genes. The strain also carried IncA/C plasmid with the size of 172914 bp and contained 10 drug-resistant genes. Combined with the genomic evolutionary relationship, this study found that the drug-resistant genes and drug-resistant plasmids carried among strains showed certain aggregation. The traditional ST type of strain SH400 was ST69, and the cgMLST type was a new type highly similar to cgST-252. Conclusion: This strain of serogroup O139 V. cholerae carries the ctxAB gene, multiple drug-resistant genes and IncA/C plasmid, and there are multiple drug-resistant islands.

Comparing the application of three thrombosis risk assessment models in patients with acute poisoning: A cross-sectional survey

Background

Patients with acute toxic hemoperfusion are prone to deep vein thrombosis. However, there is no risk assessment model for thrombosis in patients with acute toxic hemoperfusion. Therefore, we compared three commonly used risk assessment models for deep vein thrombosis to determine the model most suitable for assessment of deep vein thrombosis in patients with acute toxic hemoperfusion.

Methods

Caprini, Autar, and Padua thrombosis risk assessment models were used to assess the risk of deep vein thrombosis in patients with acute poisoning and hemoperfusion admitted to a grade A hospital in Shandong province from October 2017 to February 2019. The predictive values of the three models were compared using receiver operating characteristic (ROC) curve analysis.

Results

The risk assessment model scores of Caprini, Autar, and Padua were 7.55 ± 1.76, 8.63 ± 2.36, and 3.92 ± 0.55, respectively. The Caprini risk assessment model was significantly different (p < 0.05) in high-risk patients in the thrombus and non-thrombotic groups; the difference between the other two models was not significant (p > 0.05). The areas under the ROC curve of the Caprini, Autar, and Padua risk assessment models were 0.673, 0.585, and 0.535, respectively. The difference in areas under the ROC curve between the Caprini risk assessment model and the Autar risk assessment model as well as the Padua risk assessment model was significant (p < 0.05), but the areas under the ROC curve of the Autar risk assessment model and the Padua risk assessment model were not statistically significant (p > 0.05). The Caprini risk assessment model had a sensitivity of 91.9%, specificity of 33.1%, and a Youden index of 0.249. The sensitivity and specificity of Autar’s risk assessment model were 37.0 and 77.2%, respectively, and the Youden index was 0.141. The Padua risk assessment model had a sensitivity of 91.3%, specificity of 15.0%, and a Youden index of 0.063.

Conclusion

The three thrombosis risk assessment models were not suitable for patients with acute poisoning and hemoperfusion.

Treatment of Gastrointestinal Corrosive Burns Caused by Highly Lethal Glyphosate Solution Poisoning

Glyphosate was developed by Monsanto in the United States in the 1870s and has now become the world's best-selling pesticide. It is used in more than 100 countries and regions. Glyphosate is generally considered to be less toxic or even safe for mammals, including humans, and most patients with glyphosate poisoning have a better prognosis. However, this article reports a case of a 36-year woman who suffered severe gastrointestinal damage after oral administration of 50 ml of glyphosate. After the active rescue, scar contractures occurred in both the ooesophagus and trachea. The patient recovered clinically after undergoing reconstructive surgery. Key Words: Glyphosate poisoning, Chemical burns, Ooesophageal reconstruction, Tracheal reconstruction.

Case series: Diquat poisoning with acute kidney failure, myocardial damage, and rhabdomyolysis

Diquat is a herbicide that can have deleterious effects on the kidneys, liver, heart, lungs, and central nervous system on ingestion. Diquat poisoning-associated rhabdomyolysis has rarely been reported. We describe two cases of diquat poisoning with acute renal failure, myocardial damage, and rhabdomyolysis. Case 1: A 17-year-old man experienced anuria after ingesting ~200 mL of diquat 16 h prior. On admission, his creatinine (400 μmol/L), urea (11.7 mmol/L), creatine kinase (2,534 IU/L), and myohemoglobin (4,425 ng/mL) concentrations were elevated. Case 2: An 18-year-old woman who ingested ~200 mL of diquat 5.5 h prior to admission had normal creatinine, urea, and creatine kinase concentrations. Eleven hours after ingestion, she developed anuria with elevated creatinine (169 μmol/L) concentration; her creatine kinase (13,617 IU/L) and myohemoglobin (>3,811 ng/mL) concentrations were remarkably elevated 24 h after ingestion. Both patients also had elevated aminotransferase and myocardial enzyme concentrations. After undergoing hemoperfusion and hemofiltration, blood diquat concentrations in cases 1 and 2 on admission (16/6 h after ingestion), after hemoperfusion (20/11 h after ingestion), and after 8 h of hemofiltration/8 h of hemofiltration and 2 h of hemoperfusion (29/21 h after ingestion) were 4.9/9.1, 3.4/5.4, and 1.5/1.2 μg/mL, respectively. Severe diquat poisoning can cause acute kidney failure and rhabdomyolysis. Rhabdomyolysis may induce myocardial injury, aggravating kidney damage, and also increase transaminase concentration. Hemoperfusion and hemofiltration could be effective treatments for eliminating diquat in the blood.

Severe methyl bromide poisoning causing early acute renal failure and anuria: a case report

Methyl bromide is a pre-plant soil fumigant that is widely used to control nematodes, insects, and fungi in farmlands. Methyl bromide enters the human body through dermal absorption or inhalation and can damage the respiratory, nervous, circulatory, urinary, and other systems. A 62-year-old man who had inhaled a large amount of methyl bromide was admitted to our department. He presented with respiratory failure and pink foamy sputum. He was started on dexamethasone, alanyl glutamine, sulbactam, furosemide, vitamin B₁, mouse nerve growth factor, and other treatments, and mechanical ventilation and continuous venovenous hemodiafiltration (CVVHF) were performed daily. He subsequently developed coagulopathy because of the CVVHF, for which protamine, recombinant human brain natriuretic peptide, and albumin were administered intravenously. Notably, the patient developed sustained anuria and eventually died owing to multiple organ failure; specifically, failure of the brain, heart, lungs, and kidneys. This report presents the diagnosis, clinical course, management, and prognosis of a patient who was treated at our hospital for severe methyl bromide poisoning.

Case Report: Toxic encephalopathy caused by repeated inhalation of liquid sealant

Short-term exposure to high levels of organic solvents, as well as long-term exposure to small doses, can damage the central nervous system, thereby leading to toxic encephalopathy. However, toxic encephalopathy caused by long-term inhalation of liquid sealant is rarely reported. This study describes the clinical data of a case of toxic encephalopathy caused by repeated inhalation of liquid sealants and discusses the pathophysiological characteristics and treatment of organic solvent toxic encephalopathy. This report aims to strengthen the understanding of this disease among clinical staff.

[Establishment of multi-sector collaborative mechanism and surveillance network for Salmonella infection outbreak response and control]

Salmonellosis is one of the common food-borne diseases, local and cross-region outbreaks are not rare. The risk of cross-border transmission of Salmonella is increasing with the high frequency of global economic trades. The recently occurred multi-country outbreaks of Salmonella Typhimurium infection associated with chocolate products have highlighted the importance of improving capability of surveillance and warning of foodborne-disease, especially salmonellosis, in China. It is essential to strengthen the collaboration among clinical medicine, disease control and food safety institutions, improve the capability of whole-genome sequencing of Salmonella for the disease surveillance and tracing, and facilitate the information sharing and collaboration among the food safety related sectors for the timely detection, prevention and control of outbreaks of Salmonella infection in China.

Methemoglobinemia and Delayed Encephalopathy After 5-Bromo-2-Nitropyridine Poisoning: A Rare Case Report

5-bromo-2-nitropyridine, an intermediate in the synthesis of pharmaceutical and pesticide products, is toxic to the human body. However, 5-bromo-2-nitropyridine poisoning has not been previously reported. Here, we report the case of a 40-year-old man who suffered skin and respiratory tract exposure to leaked 5-Bromo-2-nitropyridine at work. After exposure, the patient rapidly developed dizziness, fatigue, nausea, vomiting, chest distress, diffuse cyanosis, and coma. Methemoglobinemia, hemolytic anemia, rhabdomyolysis, and acute renal failure were observed after admission. He improved markedly after treatment, but delayed encephalopathy was confirmed 82 days after the exposure. This case highlights that 5-bromo-2-nitropyridine can be absorbed through the skin and respiratory tract, resulting in methemoglobinemia and delayed encephalopathy.

Clinical Analysis of Acute Organophosphorus Pesticide Poisoning and Successful Cardiopulmonary Resuscitation: A Case Series

Acute organophosphorus pesticide poisoning (AOPP) with cardiac arrest has an extremely high mortality rate, and corresponding therapeutic strategies have rarely been reported. Therefore, this study aimed to explore the prognostic factors and effective treatments of AOPP-related cardiac arrest. This retrospective study was conducted in our department in the years 2018–2021. We conducted a descriptive analysis of the clinical manifestations, rescue strategies, and prognosis of patients with AOPP who had experienced cardiac arrest and successful cardiopulmonary resuscitation. This study included six cases of patients with AOPP in addition to cardiac arrest; in four cases, cardiac arrest occurred <12 h after ingestion, and in two, cardiac arrest occurred more than 48 h after ingestion. Five patients had not undergone hemoperfusion therapy before cardiac arrest, and all six were treated with atropine during cardiopulmonary resuscitation and subsequent pralidoxine. Four patients recovered and were discharged from the hospital, one died in our department, and one was transferred to a local hospital and died there 2 h later. The last two patients had severe pancreatic injuries and disseminated intravascular coagulation. This, along with their death, might have been related to their prognosis. Cardiac arrest can occur in patients with severe AOPP for whom antidote administration was insufficient or not timely. Application of atropine and pralidoxine in a timely manner after cardiac arrest following AOPP is the key to successful treatment. This study provides useful guidelines for the treatment of similar cases in the future.

Development and validation of a prediction model of deep venous thrombosis for patients with acute poisoning following hemoperfusion: a retrospective analysis

Objective

To develop and confirm an individualized predictive model to ascertain the probability of deep venous thrombosis in patients with acute poisoning after undergoing hemoperfusion.

Methods

Three hundred eleven patients with acute poisoning who were admitted to a hospital in China between October 2017 and February 2019 were included in the development group. Eighty patients with acute poisoning who were admitted between February and May 2019 were included in the validation group. The independent risk factors for deep venous thrombosis were examined. An individualized predictive model was developed using regression coefficients.

Results

The number of catheter indwelling days, having a catheter while being transported, elevated serum homocysteine concentrations, and dyslipidemia were independent risk factors for deep venous thrombosis following hemoperfusion in patients with acute poisoning. The areas under the receiver operating characteristic curve of the development and validation groups were 0.713 and 0.702, respectively, which suggested that the prediction model had good discrimination capacity. The calibration belts of the two groups were ideal.

Conclusions

Our prediction model has a moderate predictive effect for the occurrence of deep venous thrombosis in patients with acute poisoning. In clinical practice, this model could be combined with a common thrombosis risk assessment model.

Two cases of methaemoglobinaemia and haemolysis due to poisoning after skin absorption of 4-chloro-1-nitrobenzene

INTRODUCTION

While 4-chloro-1-nitrobenzene has oxidising properties and can lead to methaemoglobinaemia and haemolysis, such reports are rare. We herein describe two cases of 4-chloro-1-nitrobenzene poisoning after skin exposure and detail relevant clinical characteristics and treatment outcomes.

CASE PRESENTATION

A 45-year-old man and his 32-year-old male co-worker presented at our department shortly after skin exposure to 4-chloro-1-nitrobenzene. They developed similar symptoms, including dizziness, dyspnoea, excessive fatigue, and coma. Patients' chest inspection yielded normal findings. Despite maximal oxygen supplementation, neither patient exhibited improvements in the following clinical parameters: diffuse cyanosis, chocolate-coloured blood, and decreased pulse oximetry. For patients 1 and 2, methaemoglobin levels at admission were 78.6% and 63.6%, and 4-chloro-1-nitrobenzene concentrations were 4.12 μg/mL and 2.89 μg/mL, respectively. Their symptoms and methaemoglobin levels improved after we cautiously administered methylene blue; we subsequently detected oxidative haemolysis (confirmed by peripheral blood smears) that later resolved without further aggravation. No further episodes of anaemia were documented via telephone follow-up for eight months after hospital discharge for either patient.

DISCUSSION

Typical features of methaemoglobinaemia included diffuse cyanosis, dark chocolate-coloured blood, elevated partial pressure of oxygen, and decreased pulse oximetry saturation. Haemolysis likely occurred secondary to the toxic effects of 4-chloro-1-nitrobenzene.

[Application and reflection of laboratory-based monitoring in early warning of infectious diseases]

Despite the fact that our cognition towards infectious disease prevention, the advanced technology and the economic status of the whole society has made a great progress in the last decade, the outbreak of COVID-19 pneumonia has again enabled the public to acquire more about super-challenges of infectious diseases, epidemics and the relevant preventive measurements. In order to identify the epidemic signals in early stage or even before the onset of epidemic, the data research and utilization of a series of factors related to the occurrence and transmission of infectious diseases have played a significant role in research of prevention and control during the whole period of surveillance and early warning. Laboratory-based monitoring for the etiology has always been an important part of infectious disease warning system due to pathogens as the direct cause of such diseases. China has initially established a laboratory-based monitoring and early warning system for bacterial infectious diseases based on the Chinese Pathogen Identification Network with an aim to identify pathogens, outbreaks and sources. This network has played an essential role in early detection, tracking and precise prevention and control of bacterial infectious diseases, such as plague, cholera, and epidemic cerebrospinal meningitis. This issue focuses on the function of laboratory-based monitoring during the period of early warning, prevention, and control of bacterial infectious diseases, and conducted a wide range of researches based on the analysis of the epidemic and outbreak isolates, together with field epidemiological studies and normal monitoring systems. All of these could illustrate the effect of laboratory surveillance in the infectious disease risk assessment and epidemic investigation. At the same time, we have put forward our review and expectation of scenarios about laboratory-based monitoring and early warning technologies to provide innovative thoughts for promoting a leapfrog development of infectious disease monitoring and early warning system in China.

[Advance on research and application of laboratory pathogen monitoring and early warning technology of bacterial infectious diseases]

Human beings are still facing the public health challenges from bacterial infectious diseases. Carrying out systematic infectious disease monitoring and early warning is the most direct solution to prevent and control infectious diseases. Etiology is an important part of infectious disease monitoring and early warning. Effective pathogen monitoring can identify pathogens, outbreaks and sources at the first time. In this study, we have reviewed the research and application of etiology monitoring and early warning technology of bacterial infectious diseases and summarized the importance and application scenarios of etiology in infectious disease monitoring and early warning, as well as the research progress of etiology monitoring and early warning technology. Based on the work of existing laboratory monitoring networks, such as Chinese Pathogen Identification Network, the development trend and prospect of infectious disease laboratory network monitoring are put forward to provide a reference for establishing and perfecting the infectious disease monitoring and early warning system.

Kidney and lung injury in rats following acute diquat exposure

Diquat (1,1'-ethylene-2,2'-bipyridylium) is a type of widely used agricultural chemical, whose toxicity results in damage to numerous tissues, including the lung, liver, kidney and brain. The aim of the present study was to establish a rat model of acute diquat exposure and explore the relationship between diquat concentration, and kidney and lung injury, in order to provide an experimental basis for clinical treatment. A total of 140 healthy adult male Wistar rats were randomly divided into control and exposure groups. The diquat solution was administered intragastrically to the exposure group at 1/2 of the lethal dose (140 mg/kg). An equal volume of water was administered to the control group. The dynamic changes in the plasma and tissue diquat levels were quantitatively determined at 0.5, 1, 2, 4, 8, 16 and 24 h following exposure using liquid chromatography mass spectrometry. The content of hydroxyproline (HYP) in the lung tissues, as well as the levels of blood urea nitrogen (BUN), creatinine (Cr), uric acid (UA), kidney injury molecule-1 (KIM-1) and tumor growth factor (TGF)-β1, were detected using western blot analysis at every time point. Lung and kidney morphology were also assessed. Electron microscopy showed that the degree of renal damage gradually increased with time. Vacuolation gradually increased, some mitochondrial bilayer membrane structures disappeared and lysosomes increased. The lung tissue damage was mild, and the cell membrane integrity and organelles were damaged to varying degrees. The plasma and organ levels of diquat peaked at ~2 h, followed by a steady decrease, depending on the excretion rate. Over time, the serum concentrations of UA, BUN, Cr and KIM-1 were all significantly increased (P<0.05). Serum KIM-1 in rats was increased after 0.5 h, and was significantly increased after 4 h, suggesting that KIM-1 is an effective predictor of early renal injury. Early TGF-β1 expression was clearly observed in renal tissue, while no clear TGF-β1 expression was observed in the lung tissue. In conclusion, the concentration of diquat in the serum and tissue of rats with acute diquat poisoning peaked at an early stage and then rapidly decreased. The renal function damage and pathological changes persisted, the lung tissue was slightly damaged with inflammatory cell infiltration, and early pulmonary fibrosis injury was not obvious.

A rare form of intoxication: acute methyl ethyl ketone peroxide poisoning

We report two suicidal cases of acute methyl ethyl ketone peroxide (MEKP) poisoning. A woman in her late 60s suffered from oral mucosal erosion, functional impairment of the heart, liver and other organs, pulmonary inflammation, elevated inflammatory markers, pleural effusion, hypoproteinemia and metabolic acidosis after oral administration of approximately 50 mL of MEKP. After admission, the patient was administered hemoperfusion four times, 8 mg of betamethasone for 6 days and symptomatic support. Hemoperfusion had an obvious effect on the treatment of oral MEKP poisoning. After discharge, the patient developed progressive dysphagia and secondary esophageal stenosis. Supplementary feeding was administered with a gastrostomy tube after the patient was completely unable to eat. A man in his mid-40s developed oropharyngeal mucosal erosion, bronchitis and esophageal wall thickening after oral administration of 40 ml MEKP. After receiving total gastrointestinal dispersal, 80 mg of methylprednisolone was administered for 7 days, and symptomatic supportive treatment was provided. Slight dysphagia was observed after discharge, and there was no major effect on the quality of life. Patients with acute oral MEKP poisoning should be followed up regularly to observe its long-term effects on digestive tract corrosion and stenosis.

Acute diquat poisoning resulting in toxic encephalopathy: a report of three cases

INTRODUCTION

Diquat-related acute kidney injury is well-known. However, neurological disorders caused by diquat are often underestimated, and changes in the imaging findings are rarely reported. We present three cases of acute diquat poisoning resulting in toxic encephalopathy.

CASE REPORT

In the first case, a 20-year-old previously healthy man ingested approximately 80-100 mL of diquat. He developed acute renal failure, neurological disorders, and respiratory failure. Central pontine myelinolysis was considered by magnetic resonance imaging (MRI), 18 days after ingestion. In the second case, a 20-year-old man ingested approximately 100 mL of diquat. Toxic encephalopathy was confirmed by MRI, 13 days after ingestion. Unfortunately, he experienced cardiac arrest and died 18 days after ingestion. In the third case, a 31-year-old previously healthy man ingested approximately 50 mL of diquat. The imaging features of toxic encephalopathy mainly involved the medulla oblongata, pons, midbrain, bilateral brachium pontis, cerebellum, and pedunculus cerebri. He demonstrated significant recovery.

DISCUSSION

Ingestion of diquat can cause acute renal failure, neurological disorders, and respiratory failure. The pons, midbrain, pedunculus cerebri may be the most commonly impaired locations of diquat-related toxic encephalopathy.

Gluteal muscle damage and rhabdomyolysis after olanzapine poisoning: a case report

Olanzapine is a widely adopted atypical antipsychotic medication used to manage schizophrenia. Reports show that the incidence rate of adverse reactions to olanzapine is significantly lower than those of other classic antipsychotic medications. However, olanzapine overdose may be associated with severe consequences. Herein, we report a 21-year-old female patient who had taken nearly 700 mg (70 tablets) of olanzapine; she was found after 30 hours. As her condition progressed, she presented with rhabdomyolysis, swelling in the thighs and hips, paralytic ileus, digestive tract hemorrhage, and elevated serum amylase and lipase levels; notably, she recovered after treatment. This intractable case is of great clinical significance and suggests that early-phase hemoperfusion plays a critical role in olanzapine poisoning-related rhabdomyolysis.

Secondary organizing pneumonia following occupational acute nitrogen oxide poisoning: a case report

Secondary organizing pneumonia (SOP) is a nonspecific inflammatory response towards acute lung injuries caused by various diseases. However, organizing pneumonia (OP) secondary to occupational acute nitrogen oxide poisoning has been reported rarely. We report a 49-year-old man who suffered from nitrogen oxide poisoning after inhaling mixed gas at work. After pathological examination, he was diagnosed with OP. In the absence of other underlying factors causing OP, he was diagnosed with SOP owing to acute nitrogen oxide poisoning. After systematic treatment, the patient recovered and was discharged in better health. In patients with lung injury caused by acute nitrogen oxide poisoning, physicians should be alert to the risk of patients subsequently developing SOP, and timely diagnosis and treatment are essential for complete recovery.

Clinical characteristics and treatment of mixed-pesticide poisoning in a patient: reflections on a particular case

Patients who commit suicide often deliberately hide their medical history. Given that taking pesticides is one of the most common methods of suicide, other forms of poisoning may be neglected in clinical practice. We report here a case of mixed-pesticide poisoning. The patient was poisoned by oral administration of a coumarin rodenticide in combination with an intramuscular injection of organophosphorus (OP) pesticide. The patient was treated with vitamin K1, cholinesterase reactivators, atropine, ventilator-assisted ventilation, and bedside debridement. Her condition gradually stabilized and she eventually recovered and was discharged. Assessment of the causes of delayed diagnosis and treatment suggests that we need to improve early detection and treatment of acute poisoning. It is especially important to ask about the patient’s medical history, conduct a careful physical examination, and track the clinical symptoms and differential diagnosis of common poisoning. In addition to the three common routes of poisoning—oral, inhalation, and cutaneous mucosal contact—intramuscular injection of OP can also lead to severe poisoning, which manifests as respiratory failure.

Role of the Hippo signaling pathway in safflower yellow pigment treatment of paraquat-induced pulmonary fibrosis

OBJECTIVE

To elucidate the molecular mechanisms by which safflower yellow (SY) mediates therapeutic effects in rats with paraquat intoxication-induced pulmonary fibrosis.

METHODS

Rats received combinations of paraquat, SY, and SB431542, a transforming growth factor (TGF)-β1 receptor antagonist. Survival over 28 days was assessed by Kaplan-Meier analysis. Rat tissue and serum samples were assessed by hematoxylin and eosin staining, Masson's Trichrome staining, immunoblotting, quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, and transmission electron microscopy.

RESULTS

Survival rates were higher in SY and SB431542 groups (treatment and paraquat) than in the exposure group (paraquat alone). In the exposure group, serum TGF-β1 levels increased between days 3 and 14; mammalian STE20-like (MST) levels increased between days 3 and 7; TGF-β1 and Smad3 levels increased between days 3 and 14; and Yap and connective tissue growth factor levels increased between days 3 and 28. TGF-β1 levels were lower in SY and SB431542 groups than in the exposure group. Pathology scores were higher in exposure, SY, and SB431542 groups than in the control group throughout the experiment.

CONCLUSIONS

In rats with paraquat intoxication-induced pulmonary fibrosis, Hippo signaling could be activated by the MST-Yap pathway; SY and SB431542 could alleviate pulmonary fibrosis via Hippo signaling.

Esophagitis dissecans superficialis associated with acute transoral paraquat poisoning: Clinical study of 15 cases

To analyze the clinical characteristics and therapeutic effects of transoral paraquat poisoning combined with Esophagitis dissecans superficialis (EDS). A retrospective observational study was conducted on paraquat poisoning patients between January 1, 2011 and August 30, 2016 in Qilu hospital. Fifteen patients with EDS were enrolled in this study. The clinical characteristics, prognosis, and pathological features of esophageal necrosis mucosa of these patients were retrospectively analyzed and summarized. Esophageal mucosal dissection occurs mainly within 3-8 days after transoral paraquat poisoning in 15 patients. Dosage of paraquat is range from 50 to 100 ml. Most patients have physical problems with swallowing before the intramural esophageal dissection occurred. And there are other symptoms, including sore throat or dysphagia (100%), nausea and vomiting (86.7%), heartburn or upper abdominal pain (73.3%), hematemesis (60%), abdominal distension (20%) and cough frequently (6.7%). In death group, most patients demonstrate features of the multiple organ failure when the esophageal mucosal stripping happened, including lung injury, renal failure, and hepatic failure. The shape of esophageal dissection was tubular in 60%, irregular in 40%, and they vary in size. Pathological examination showed extensive injury, necrosis and hemorrhage of digestive tract epithelium, and obvious inflammatory reaction of epithelial tissue. Transoral paraquat poisoning has certain damage to the patient's esophageal mucosa, and some may be complicated with EDS, and the prognosis is poor, especially when combined with multiple organ dysfunction. Esophageal damage is mainly located in the esophageal mucosa and have different degrees. Special attention should be paid on such patients.

[Research progress on bacterial resistance and gene carrying resistance in migratory birds]

Bacterial resistance is a serious problem in use of antibiotics and an urgent global public health challenge. The drug-resistant bacteria and drug-resistant genes carried by migratory birds are not only related to clinical antibiotics, but also the use of pesticides and veterinary drugs as well as the pollution of the surrounding environment of drug factories. However, studies on drug-resistant genes carried in migratory birds have been gradually reported around the world. Migratory birds have the characteristics of large range of movement and long flight distance, which leads to the complexity of bacterial resistance. Under the influence of environment and human activities, drug-resistant genes carried in bacteria are transmitted among species,human beings, domestic animals, environment and wild birds through mobile elements. This study summarizes the current situation of antibiotic resistance bacteria carried by migratory birds,the status of drug-resistant genes in migratory birds and the relationship between the resistance of migratory birds and the environment and human activities. The aim is to better understand the important role of migratory birds as hosts and vectors in the global spread of antibiotic resistance.

[Current status, progress and suggestions regarding prevention and control of brucellosis in China]

Brucellosis is a neglected zoonosis, which not only endangers health of the people but also affects the development of animal husbandry, tourism and international trade as well as food safety. In the past two decades, great progress has been achieved in the prevention and control of both human and animal brucellosis, however, tremendous challenges still exists in the control and eradication of brucellosis, especially in the developing countries. In recent years, along with the increase of livestock breeding and animal or related product trade, human contacts with livestock has increased, resulting in the expansion of brucellosis endemic areas. In China, the brucellosis endemic areas are mainly distributed in Inner Mongolia and adjacent provinces, which might be explained by a lot of reasons, such as the development of animal husbandry, emerging and re-emerging of brucellosis endemic area and the movement of infection sources and degree of paid-attention. This paper summarizes the current status and progress in brucellosis prevention/control and surveillance in China and puts forward suggestions for the future improvement.

Effects of tacrolimus on the TGF‑β1/SMAD signaling pathway in paraquat‑exposed rat alveolar type II epithelial cells

Paraquat is a highly toxic pesticide, which often causes pulmonary interstitial fibrosis after poisoning, and there is no specific antidote. At present, limited studies have reported that tacrolimus, as an immunosuppressant, can inhibit pulmonary fibrosis, but the specific mechanism remains unknown. The aim of the present study was to demonstrate the effect of tacrolimus on the TGF-β1 pathway associated with pulmonary fibrosis in paraquat exposed alveolar type II epithelial cells, and to identify the antipulmonary fibrosis mechanism of tacrolimus The rat alveolar epithelial type II RLE-6TN cell line was exposed to paraquat and treated with or without tacrolimus for 24 h, or with a TGF-β1 receptor type I/II inhibitor (LY2109761) for 1, 4, 8 or 16 h. MTT assays were used to detect the viability of rat alveolar type II epithelial cells under these different treatment conditions, while the concentrations of TGF-β1, SMAD3, SMAD7 and connective tissue growth factor (CTGF) in the cell culture supernatant were determined using ELISAs. Additionally, reverse transcription-quantitative PCR and immunofluorescence were used to analyze the mRNA and protein expression levels of TGF-β1, SMAD3, CTGF and SMAD7. The results demonstrated that the inhibition of the proliferation of RLE-6TN cells exposed to 200 nmol/l paraquat was 26.05±2.99%. The inhibition rate of 10 ng/ml tacrolimus on paraquat-exposed alveolar type II epithelial cells was 18.40±3.49%. The inhibition rate caused by 5 µmol/l LY2109761 was 26.56±4.49%. The expression levels of TGF-β1, SMAD3 and CTGF, as well as their concentrations in the culture supernatant, were significantly downregulated in the tacrolimus group compared with the paraquat group. However, both the concentration and expression levels of SMAD7 were significantly upregulated in the tacrolimus group compared with the paraquat group. In conclusion, tacrolimus can reduce the levels of TGF-β1, SMAD3 and CTGF, increase the level of SMAD7 in TGF-β1 signaling pathway and protect the development of pulmonary fibrosis in paraquat exposed alveolar epithelial cells.

[Genomic recombination of the vibrio cholerae serogroup O1 El Tor pandemic strains]

Objective: To analyze the genomic recombination of the vibrio cholerae serogroup O1 El Tor pandemic strains. Methods: A total of 292 complete or draft genome sequences of Vibrio cholerae O1 serogroup El Tor strains isolated from 1937 to 2015 were selected from National Biotechnology Information Center database. The genome alignment of strains was computed by snippy software by using N16961 as reference sequence. Then ClonalFrameML software was used to do the recombinant analysis. The wilcox.test function in agricolae package was used to compare the number recombinant segments and the total length of recombinant regions between small and large chromosomes. The kruskal function was used to compare the number recombinant segments and the total length of recombinant regions among different isolation continents. The KOBAS tool was used to do the gene ontology enrichment analysis of recombinant hotspot genes. Results: Of all 292 strains of Vibrio cholerae, 163 strains (55.8%) were recombined. The median of normalized recombinant segment number of small chromosome was 4.7×10(-6) (9.3×10(-7), 2.0×10(-5)), which was significantly larger than that of large chromosome [2.4×10(-6) (3.4×10(-7), 5.7×10(-6))] (P<0.001). The median (P(25),P(75)) of recombinant segment number of strains isolated from Africa, Asia, Europe, North America and South America were 23(1.0,33.0), 1.0(0.0,34.0), 6.0(2.0,13.0), 0.0(0.0,1.0) and 29.5(6.8,56.8), respectively, and the difference was statistically significant (P<0.001). The median (P(25),P(75)) of total length of recombinant regions of strains isolated from Africa, Asia, Europe, North America and South America were 233.0(4.0, 461.0), 11.0(0.0, 695.5), 56.0(4.0,111.0), 0.0(0.0,9.0) and 347.5(132.8,1 323.5) bp, respectively, and the difference was statistically significant (P<0.001). Gene ontology Enrichment analysis showed that the functions of 62 recombinant hotspot genes were mainly enrichment in chemotaxis, taxis, response to external stimulus, receptor activity and molecular transducer activity. Conclustion: In this study, we found that there were significant differences in the number of recombinant fragments and the length of recombinant regions between large and small chromosomes of Vibrio cholerae El Tor. We also found significant differences in the number of recombinant fragments and the total length of recombinant regions among different continents.

Fetal outcomes after intentional ingestion of paraquat: A case report

RATIONALE

Despite the fact that treatment of paraquat poisoning in pregnant women and their fetuses is challenging and raises ethical issues, it is rarely reported in the literature. We report the case of a pregnant woman who took paraquat intentionally.

PATIENT CONCERNS

A 36-year-old woman at 38 weeks gestational age, in an apparent suicide attempt, drank 1 mouthful (about 20 ml) of paraquat solution. Ten hours later, her urine dithionate test showed light blue color with a plasma paraquat concentration of 0.547 μg/ml. Six hours after admission, a male infant, whose plasma paraquat concentration was 0.761 μg/ml, together with 0.673 μg/ml in the amniotic fluid measured by high-performance liquid chromatography, was delivered but the woman's lung, liver, and kidney function declined rapidly.

DIAGNOSIS

INTERVENTIONS:: Because of placenta previa and multiple organ failure, emergency cesarean section, and panhysterectomy were performed for the pregnant woman. Intravenous injection of antibiotic to prevent infection and dexamethasone 30 mg once a day were administered. Mechanical ventilation was performed for the infant and meropenem and penicillin injection was administered.

OUTCOMES

The infant died 33 hours after birth while the mother died on the 3rd day after ingestion.

LESSONS

Paraquat can enter the fetus through the placenta and the amniotic fluid via fluid exchange. The pathological changes of fetal organs may relate to gestational age, and the prognosis was very poor in both the mother and the fetus.

[Study on the mechanism of serotype conversion of historical isolates of Shigella flexneri]

Objective: The serotype screening of Shigella flexneri from 1934 to 1965 preserved by the National Center for Medical Culture Collections was carried out, and the molecular characteristics of the serotype conversion strains were studied. Methods: Serotyping of Shigella flexneri in this study was conducted by slide agglutination and multiplex PCR, respectively. The gtrⅡ gene sequence alignment and pulsed field gel electrophoresis typing were performed on the serotype conversion strains. Results: Among the 255 strains of Shigella flexneri preserved in CMCC (B) from 1934 to 1965, 79 were carrying gtrⅡ gene, of which 19 strains and 1 strain were agglutinated with the Y serotype and X serotype, respectively, and furthermore, the multiplex PCR assays results showed serotypes 2a and 2b, respectively, and the strains were considered to have serotype conversion. The 20 strains carrying the gtrⅡ gene showed multiple nucleotide mutations. Besides 3 strains of 3 amino acid mutations, the amino acid sequences of the other 17 strains showed a stop codon in advance, resulting in functional inactivation of gtrⅡ. PFGE analysis revealed that the similarity between the serotype Y strain carrying the gtrⅡ gene and the serotype 2a strain was 75.8%-100%, and the similarity between the serotype X strain carrying the gtrⅡ gene and the serotype 2b strain was 81.6%-100%. Conclusion: Mutations in the gtrⅡ gene are more complicated in serotype-transforming Shigella flexneri serotype Y or X strains. Molecular typing suggests that the serotype-transforming Shigella flexneri serotype Y or X strains may be derived from the Shigella flexneri serotype 2a or 2b, and advance the serotype conversion to 1949.

A new sight for paraquat poisoning from immunology

Paraquat (methyl viologen, PQ) is highly toxic to humans. Pulmonary fibrosis is the most common cause of death after PQ poisoning. However, no effective therapy is available. The current treatment dilemma and pathology suggest that we should reconsider how to treat the poisoning using other methods, such as immunization. Some clues indicate that immune mechanisms may play important roles in the pathology of PQ poisoning. We implemented a simple experiment to test the hypothesis that activated innate immunity was involved in acute lung injury induced by PQ. Six rats were randomly distributed to two groups: PQ poisoning group and Immunosuppression group (cyclophosphamide pretreatment). Forty-eight hours after PQ administration, rats were anesthetized. The right lungs were excised for histopathology. The experimental results confirmed that in the set of immune deficiency, the inflammatory response in Immunosuppression group could not be effectively triggered so the lung pathology was much better than PQ poisoning group. The immunopathogenic mechanism of PQ poisoning may be essentially a sterile inflammation triggered and amplified by damage-associated molecular patterns (DAMPs). If the hypothesis is established, it may change the therapeutic regimen of PQ poisoning and the prognosis of patients.

[Comparison of colonization ability of O1 and O139 Vibrio cholerae strains on soft-shelled turtle's surface]

Objective: To study the preferred colonization sites of O1 Vibrio cholerae (V.cholerae) and the colonization ability difference for O1 and O139 V. cholerae on soft-shelled turtle's surface. Methods: 8 O1 and O139 V. cholerae strains were obtained from branch of diarrheal diseases, Chinese center for disease control and prevention. 63 soft-shelled turtles weighing 150 g and 9 cm in length (diameter of calipash) were selected for use in the study. The preferred colonization sites and proliferation trend were studied by using bioluminescent imaging method. The colonization factors for O1 V. cholerae strains were studied by constructing colonization gene mutant strains (VC1897dmshA, VC1897dgbpA and VC1897dtcpA), performing competition colonization assays and analyzing the competitive indexes. After pairing off O1 and O139 strains respectively to perform 16 competition groups, the colonization difference of these two strains were studied by competition colonization assays. Results: The colonization sites by V. cholerae on soft-shelled turtles surfaces was clustered. More V. cholerae strains colonized on turtle's calipash and carapace on dorsal side and less strain colonized on ventral side. The competition colonization assays showed that colonization ability of O1 serogroup mshA mutant strains were 7.26 times lower than VC1897dlacZ. Besides, the CI value (O139/O1) of 11 out of the 16 competition groups were greater than 2 (between 2.07 and 59.84). Two groups showed values of 1.43 and 0.93 respectively and 3 groups lower than 0.7. Conclusion: The preferred colonization sites for O1 V. cholerae strains on body surface were observed.MSHA was one of the main colonization factors for its colonization. Our study suggested that in general, O139 V. cholerae strains have stronger colonization ability than O1 strains. Besides, strains isolated from soft-shelled turtles tend to have stronger colonization ability than strains isolated from patients.

[Spatial and temporal clustering characteristics of typhoid and paratyphoid fever and its change pattern in 3 provinces in southwestern China, 2001-2012]

Objective: To analyze the spatial and temporal clustering characteristics of typhoid and paratyphoid fever and its change pattern in Yunnan, Guizhou and Guangxi provinces in southwestern China in recent years. Methods: The incidence data of typhoid and paratyphoid fever cases at county level in 3 provinces during 2001-2012 were collected from China Information System for Diseases Control and Prevention and analyzed by the methods of descriptive epidemiology and geographic informatics. And the map showing the spatial and temporal clustering characters of typhoid and paratyphoid fever cases in three provinces was drawn. SaTScan statistics was used to identify the typhoid and paratyphoid fever clustering areas of three provinces in each year from 2001 to 2012. Results: During the study period, the reported cases of typhoid and paratyphoid fever declined with year. The reported incidence decreased from 30.15 per 100 000 in 2001 to 10.83 per 100 000 in 2006(annual incidence 21.12 per 100 000); while during 2007-2012, the incidence became stable, ranging from 4.75 per 100 000 to 6.83 per 100 000 (annual incidence 5.73 per 100 000). The seasonal variation of the incidence was consistent in three provinces, with majority of cases occurred in summer and autumn. The spatial and temporal clustering of typhoid and paratyphoid fever was demonstrated by the incidence map. Most high-incidence counties were located in a zonal area extending from Yuxi of Yunnan to Guiyang of Guizhou, but were concentrated in Guilin in Guangxi. Temporal and spatial scan statistics identified the positional shifting of class Ⅰ clustering area from Guizhou to Yunnan. Class Ⅰ clustering area was located around the central and western areas (Zunyi and Anshun) of Guizhou during 2001-2003, and moved to the central area of Yunnan during 2004-2012. Conclusion: Spatial and temporal clustering of typhoid and paratyphoid fever existed in the endemic areas of southwestern China, and the clustering area covered a zone connecting the central areas of Guizhou and Yunnan. From 2004 to 2012, the most important clustering area shifted from Guizhou to Yunnan. Findings from this study provided evidence for the identifying key areas for typhoid and paratyphoid fever control and prevention and allocate health resources.

Tetramethylpyrazine can ameliorate hepatocellular mitochondrial dysfunction by decreasing the inflammatory response and increasing AQP8 protein expression in septic rats

Sepsis, which could lead to mitochondrial dysfunction and cellular energy loss, always induces acute liver injury and has a high mortality rate. Tetramethylpyrazine (TMP) is an active extract from the Chinese herb Ligusticum chuanxiong and exhibits anti-sepsis activity. In this study, a rat sepsis model was first established via cecal ligation and puncture (CLP). Then, 48 Sprague Dawley male rats were randomly divided into four groups (12 rats in each group): control group (C), sepsis group (S), TMP treatment group (T), and TMP prevention group (P). Serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT), mitochondrial aspartate aminotransferase (mAST), and adenosine triphosphate (ATP) levels and mitochondrial membrane potential (MMP) were measured and used as indicators of hepatic dysfunction severity and mitochondrial function. In addition, the activities of Na+-K+-ATPase, Mg2+-ATPase, Ca2+-ATPase, and Ca2+-Mg2+-ATPase in the mitochondrial membrane, the expression level of AQP8 and some inflammatory factors, and the level of oxidative stress were measured to explore potential mechanisms. We found that AQP8 accepts signals from inflammatory factors upon stimulation and during various infections, and low AQP8 expression levels could result in further downstream mitochondrial dysfunction. In conclusion, our data demonstrated that TMP could ameliorate hepatocellular mitochondrial dysfunction by decreasing the inflammatory response and increasing AQP8 protein expression.

[An outbreak of paratyphoid fever in a county of Yunnan province, 2010-2011]

Objective: To identify the source and to comment on control program regarding an outbreak of paratyphoid A fever in a county, through field studies. Methods: Descriptive epidemiological methods were adopted to describe the epidemiological characteristics of the outbreak, which occurred in Yuanjiang county, Yunan province between 2010-2011, China. Case-control study with environmental investigation was performed to identify related risk factors and pathogens while isolation and susceptibility on the suspected pathogens were conducted. Subsequently, intervention and preventive measures were taken for the control of the outbreak. Results: A total of 600 cases were diagnosed and reported as paratyphoid fever A which spread over the whole Yuanjiang county, including 10 townships with different incidence rates. The disease was spatially clustered and the prevalence rates in these townships decreased with increasing distances from the polluted fields. Data from the case-control study discovered that consumption of raw vegetables was the main risk factor associated with this outbreak of paratyphoid fever (OR=65.3, P<0.001). Management of patients did not meet the requirements while feces and urine of the outpatients polluted the wastewater system in the city. Salmonella paratyphi A isolates were identified from the improperly disinfected wastewaters in hospitals and city systems, respectively. After the measures as prohibiting the planting of vegetables in contaminated fields and disinfection of hospital wastewater were taken, the outbreak subsided. Conclusions: Urban and hospital wastewater used for vegetables irrigation together with the tradition of eating uncooked vegetables seemed responsible for the outbreak of this paratyphoid fever. Intervention programs carried by the local government played a key role in controlling this large outbreak.

Esophageal mucosa exfoliation induced by oxalic acid poisoning: A case report

This study reports the case of a 44-year-old woman with oral oxalic acid poisoning. As the illness progressed, the patient exhibited severe metabolic acidosis, large-area esophageal mucosa injury and acute kidney injury, which required dialysis. A guide wire slipped out of position during the process of hemodialysis and moved back and forth in the veins, but was removed successfully by interventional endovascular treatment. However, the patient's esophageal mucosa exfoliated, which lead to severe benign esophageal stenosis and dysphagia. Balloon distention was conducted twice in the upper digestive tract using X-ray location in combination with a dumb-bell bladder and interventional wire. The patient exhibited convulsions, shock, embolism and loss of consciousness while undergoing the second balloon distention procedure. Following symptomatic treatment, the patient eventually remained in a stable condition, the digestive tract expansion procedure was not resumed and a jejunostomy was performed in order to facilitate enteral nutrition, which was administered via the jejunum and had little stimulatory effect on the pancreas. Following various treatments, the patient's condition improved markedly, with renal function returning to normal.