Chemical Poisoning Research Articles

Clinical toxicology evolution of body packers between 1997 and 2011

Metabolic pathways in humans have been elucidated for most therapeutic drugs, drugs of abuse, and various chemical/solvents. In most drug overdose cases and chemical exposures, laboratory analysis is directed toward identification and quantitation of the unchanged drug or chemical in a biologic fluid such as serum or whole blood. Specifically, most clinical laboratories routinely screen and quantitate unchanged methanol and/or ethylene glycol in suspected poisonings without toxic metabolite analysis. Martin-Amat established in 1978 that methanol associated toxicity to the optic nerve in human poisonings was due to the toxic metabolite formic acid found in methanol poisonings and not due to the direct action by unchanged methanol. Jacobsen reported in 1981 that ethylene glycol central nervous system and renal toxicity were primarily due to one acidic metabolite (glycolic acid) and not due to unchanged ethylene glycol. The first objective of this review is to describe clinical experience with formic acid and glycolic acid analysis in methanol and ethylene glycol human poisonings. Drug metabolite analysis also provides useful information in the assessment and monitoring of drug use in psychiatry and substance abusing populations. Drug analysis in substance abuse monitoring is focused on urine analysis of one or more major metabolites, and less frequently on the unchanged drug(s). Serial monitoring of the major urinary cannabinoid metabolite (Δ9-THC-COOH) to creatinine ratios in paired urine specimens (collected at least 24 h apart) could differentiate new marijuana or hashish use from residual cannabinoid metabolite excretion in urine after drug use according to Huestis. The second objective is to demonstrate that creatinine corrected urine specimens positive for cannabinoids may help differentiate new marijuana use from the excretion of residual Δ9 -THC-COOH in chronic users of marijuana or hashish. Analysis of toxic chemical metabolites are helpful in the assessment and treatment of chemical poisoning whereas serial monitoring of urinary cannabinoid metabolites are predictive of illicit drug use in the substance abusing population.

White spotting variant mouse as an experimental model for ovarian aging and menopausal biology.

Menopause is a unique phenomenon in modern women, as most mammalian species possess a reproductive period comparable with their life span. Menopause is caused by the depletion of germ cell-containing ovarian follicles and in laboratory studies is usually modeled in animals in which the ovarian function is removed through ovariectomy or chemical poisoning of the germ cells. Our objective was to explore and characterize the white spotting variant (Wv) mice that have reduced ovarian germ cell abundance, a result of a point mutation in the c-kit gene that decreases kinase activity, as a genetic model for use in menopause studies. Physiological and morphological features associated with menopause were determined in female Wv/Wv mice compared with age-matched wildtype controls. Immunohistochemistry was used to evaluate the presence and number of follicles in paraffin-embedded ovaries. Bone density and body composition were evaluated using the PIXImus x-ray densitometer, and lipids, calcium, and hormone levels were determined in serum using antigen-specific enzyme immunoassays. Heart and body weight were measured, and cardiac function was evaluated using transthoracic echocardiography. The ovaries of the Wv/Wv females have a greatly reduced number of normal germ cells at birth compared with wildtype mice. The remaining follicles are depleted by around 2 months, and the ovaries develop benign epithelial lesions that resemble morphological changes that occur during ovarian aging, whereas a normal mouse ovary has numerous follicles at all stages of development and retains some follicles even in advanced age. Wv mice have elevated plasma gonadotropins and reduced estrogen and progesterone levels, a significant reduction in bone mass density, and elevated serum cholesterol and lipoprotein levels. Moreover, the Wv female mice have enlarged hearts and reduced cardiac function. The reduction of c-kit activity in Wv mice leads to a substantially diminished follicular endowment in newborn mice and premature depletion of follicles in young mice, although mutant females have a normal life span after cessation of ovarian function. The Wv female mice exhibit consistent physiological changes that resemble common features of postmenopausal women. These alterations include follicle depletion, morphological aging of the ovary, altered serum levels of cholesterol, gonadotropins and steroid hormones, decreased bone density, and reduced cardiac function. These changes were not observed in male mice, either age-matched male Wv/Wv or wildtype mice, and are improbably caused by global loss of c-kit function. The Wv mouse may be a genetic, intact-ovary model that mimics closely the phenotypes of human menopause to be used for further studies to understand the mechanisms of menopausal biology.

Experimental and theoretical analysis of H2S effects on MCFCs

Abstract One important advantage of MCFCs is the possibility of using different fuel gases (natural gas, coal gas, biogas, landfill gas, etc.). However, these fuels contain impurities that can damage MCFCs, and, of these, sulphur compounds seem to be the most harmful, even at low concentrations. The aim of this work is to test the effect of different H 2 S compositions on operating variables, investigate the relationships, propose phenomena reading and obtain new information to define tolerance limits. In particular, chemical, electrochemical and physical poisoning mechanisms were taken into account, trying to evaluate their importance studying the effects of exposure time, temperature and current density on MCFC performance when H 2 S polluted anodic gas is fed. To support the investigation, experimental tests were performed at the Fuel Cell Research Center laboratories of KIST (South Korea) and a theoretical analysis was also proposed to suggest operating strategies, for example showing how high current density or temperature values can emphasize the negative effect of poisoning. The results obtained gave new suggestions for approaching data interpretation, confirming the possibility of using MCFCs when a number of ppm of H 2 S is present in the feeding fuel.

TiO2 Nanotube Array Sensor for Detecting the SF6 Decomposition Product SO2

The detection of partial discharge through analysis of SF6 gas components in gas-insulated switchgear, is significant for the diagnosis and assessment of the operating state of power equipment. The present study proposes the use of a TiO2 nanotube array sensor for detecting the SF6 decomposition product SO2, and the application of the anodic oxidation method for the directional growth of highly ordered TiO2 nanotube arrays. The sensor response of 10–50 ppm SO2 gas is tested, and the sensitive response mechanism is discussed. The test results show that the TiO2 nanotube sensor array has good response to SO2 gas, and by ultraviolet radiation, the sensor can remove attached components very efficiently, shorten recovery time, reduce chemical poisoning, and prolong the life of the components.

Determination of Histamine in Seafood by Hydrophilic Interaction Chromatography/Tandem Mass Spectrometry

A simple method was developed to determine histamine, an important compound in chemical food poisoning, by extraction followed by hydrophilic interaction chromatography-tandem mass spectrometry using a hydrophilic column with sulfobetaine-type zwitterion groups. The quantitation range in seafood products was from 0.4 to 200 mg kg(-1) for 5 g food samples. Quantitative recoveries were obtained with four types of seafood product. These results agreed well with those from the more complex, conventional HPLC method, which requires sample derivatization with dansyl chloride.

ACUTE RENAL FAILURE IN ACUTE POISONING: PROSPECTIVE STUDY FROM A TERTIARY CARE CENTRE OF SOUTH INDIA

Cases of people presenting with poisoning are likely to develop acute renal failure (ARF), which may be due to multiple mechanisms/aetiologies. These cases need careful observation and appropriate treatment. To find the risk of ARF among acute poisoning cases, identify the underlying causes and to analyse the outcome. In this prospective study with nested case control, 1,250 cases admitted to the Poison Control, Training and Research Centre of Government General Hospital, Madras Medical College were monitored and evaluated for development of ARF. Patients with history of diabetes/hypertension, known chronic kidney disease, chronic NSAID therapy, those on drugs that increase serum creatinine by inhibiting creatinine secretion and other co-morbid illnesses were excluded. Data were interpreted after subjecting them to bivariate logistic regression and then step wise multivariate analysis. Thirty-two cases developed ARF. Twenty-four were due to snake bite, the rest due to chemical poisons. Chances of developing ARF were greater (6.15%) among the poisoning due to bites and stings than chemical poisoning (0.9%). Five in the former and seven in the latter expired. Among cases bitten by snakes, only 22 (7%) cases bitten by Russell Viper Daboia russelii developed renal failure. Copper sulphate and rat killer poisonings were the commonest causes of chemical induced ARF, dichromate, indigenous medicines and vasmol 33 (paraphenelyne diamine) were the least causes for ARF. None of the patients with organophosphate developed ARF nor did any of the 150 admitted for overdose of medicines developed ARF. The risk of ARF among the cases of poisoning was 2.5%. The outcome of ARF among bites and stings was better than chemical poisoning, and the difference was highly significant (p= 0.005, OR = 0.04-1.0, 95% CI = 0.004-0.38). Early recognition and appropriate measures reduce the occurrence of ARF.

Clinical research of severe burn patients with chemical poisoning treatment by continuous renal replacement therapy

Objective To investigate the influence of biochemical indices and coagulation function in severe burn patients with chemical poisoning by continuous renal replacement therapy(CRRT)treatment.Methods 60 patients were randomly divided into CRRT treatment group(n=30)and basic therapy(n=30).The control group received conventional treatment,based therapies in the treatment group based on the use CRRT treatment,the average course of 2 or 3 times to observe the biochemical indicators coagulation,and cytokine before treatment compared with that after treatment.Results In treatment group,the index of heart rate,arterial partial pressure of oxygen,blood urea nitrogen,serum creatinine after treatment[(110.0±26.0)times/min,(93.3±11.0)mm Hg,(6.1 ±1.3)mmol/L,(106.4±24.8)μmol/L],compared with before treatment[(148.0±38.0)times/min、(84.5 9.1)mm Hg,(8.6±1.9)mmol/L,(172.6 ±29.8)μmol/L]were significantly different(t=2.154,2.345、2.458,2.544,all P＜0.05),and compared with control group[(133.0±37.0)times/min,(86.5 ±9.9)mm Hg,(8.3 ±2.0)mmol/L,(134.6±26.8)μmol/L]were statistically significant(t=2.174,2.245,2.558,2.444,all P＜0.05);The index of IL-1,IL-6,IL-8,TNF-α after treatment in treatment group[(260.7 ±25.9)ng/L,(327.6±129.2)ng/L,(300.3±146.6)ng/L,(97.1±22.3)ng/L)compared with control group after treatment[(368 .2±24.8)ng/L,(400.2±198.3)ng/L,(482.9±198.5)ng/L,(225.0 ±22.3)ng/L]had significant differences(t=2.314、2.371、2.278、2.316,all P＜0.05).Conclusion The treatment group of patients with severe burns could remove the inflammatory mediators and cywkines,to improve their inflammatory state and maintain stability in the environment. Key words: Renal replacement therapy; Burn,inhalation; Cytokines

Current situation of emergency resources and ability to deal with sudden chemical poisoning in 11 institutions for occupational diseases or disease control in the west of Guangdong

Obhective To investigate emergency resources and ability to deal with sudden chemical poisoning in the west of Gnangdong province.Methods Related information of 11 Poison Control Centers(PCCs)and Cemteof Diseases Control(CDCO were collected and investigated by questionnaire survey,and then used statistical methods to analyze the databases.Results In 11 PCCs or CDCs,there were only 7 institutions found to have established work place monitoring system;while only 11 institutions allocated 15 equipments on average,including 3 kinds of personal protective equipment,10 kinds of sampling and preserving equipment and 2 kinds of rapid identification equipments.Conclution The PCCs and CDCs in the west of Guangdong province still have a long way to adapt sudden chemical poisoning in many aspects such as teanl instruction,personal protective equipmem allocation,laboratory equipment,material reserve,information network,contingency plan system,etc. Key words: Sudden; Chemical poisoning; Emergency resources; Emergency ability; Investigation

Suppression of the oxygen storage and release kinetics in Ce0.5Zr0.5O2 induced by P, Ca and Zn chemical poisoning

The present investigation concerns for the first time the understanding of the individual and combined effects of phosphorous with calcium or zinc deposited on a Ce0.5Zr0.5O2 solid followed by calcination in 20%O2/He at 850°C, on the kinetics of oxygen storage and release of the thus derived contaminated Ce0.5Zr0.5O2 solids. Towards this aim, physicochemical and redox properties of Ce0.5Zr0.5O2, P/Ce0.5Zr0.5O2, P–Ca/Ce0.5Zr0.5O2 and P–Zn/Ce0.5Zr0.5O2 solids were investigated by means of BET, XRD, SEM, XPS, TPR, OSC and TPIE techniques. P, Ca or Zn deposition on Ce0.5Zr0.5O2 solid was found to result in a drastic decrease in the population of reactive oxygen species present on the surface and within the subsurface/bulk region of the solid. The latter is attributed to the formation of cerium and calcium phosphates in the subsurface region of the solid, as well as to the formation of zinc oxide on the surface of the solid, clogging pores lower than 10nm in size as revealed by BJH pores size distribution measurements. Another reason for the severe reduction in the OSC (up to 70%) of contaminated by phosphorous Ce0.5Zr0.5O2 solid is the rearrangement of its surface composition resulting in the lowering of the Ce/Zr surface ratio. The latter is linked to the lowering of the concentration of reactive oxygen associated with the strength of Ce–O–Zr bonding. The incorporation of P within the subsurface region of Ce0.5Zr0.5O2 crystals and its reaction with the solid producing CePO4 causes the formation of a significant amount of Ce3+ which is very difficult to get re-oxidised, and locks the Ce(III)/Ce(IV) redox couple. Phosphorus incorporation within the subsurface/bulk of Ce0.5Zr0.5O2 solid oxide particles was found to significantly increase the activation energy of bulk oxygen diffusion from 126.5 to ∼169.0kJmol−1, while the concurrent deposition of Ca or Zn along with P was found to strongly suppress surface oxygen diffusion.

In-Situ Measurement of SOFC Anode Surface Processes

One of the remaining challenges facing state-of-the-art nickel-based SOFC anodes is their susceptibility to degradation induced by redox cycling and chemical poisoning, most notably by carbon and sulphur. An enhanced scientific understanding of chemical interactions on the surface of SOFC electrodes is therefore critical to the development of robust nickel-based anodes. This paper draws together work on advanced electrochemical studies, thin-foil samples, and Raman spectroscopy studies of anode materials, together with results from a new customized SOFC test rig using combined in situ Raman and electrochemical measurements. The in situ test rig opens up a whole range of new research possibilities and these will be discussed.

Pediatric Poisonings and Risk Markers for Hospital Admission in a Major Emergency Department in Romania

To identify the prevalence, characteristics, and risk markers for childhood poisonings treated in the emergency department of a large Romanian hospital. Trauma registry data using ICD-10 codes and case summaries were studied to identify poisonings among children aged 0-18. Multivariate logistic regression identified factors associated with hospital admission. Between 1999 and 2003, 1,173 pediatric trauma cases were seen in the emergency department; 437 (37.3%) were treated for poisoning, including medication (35%), alcohol (26%), chemical products (19%), and carbon monoxide (14%). Half of all poisonings were unintentional, primarily affecting children < 10 years. Half were intentional, mainly affecting children 10-18. Females were three times more likely than males to have documented suicidal intent (P < .0001). Over 30% of suicide attempts were among children ages 10-14 (P < .0001). We report significantly increased adjusted odds ratios (P < .05) of hospital admission for children 10-18, and for chemical substance poisoning, and suicidal intent. Pediatric poisoning is a serious public health issue in Romania, and we suggest these findings are relevant across other eastern European countries with limited resources. Poisonings result in morbidity and hospital admissions, yet there are few prevention resources available. Health education programs and consumer product safety policies are needed in Romania and eastern Europe.

Occupational Health and Safety Challenges in China—Focusing on Township-Village Enterprises

ABSTRACT China has experienced dramatic industrialization, urbanization, and economic growth over the last 3 decades. The rapid transformation and dramatic prosperity of industries in rural areas have, in turn, created tremendous challenges for occupational health and safety (OHS). This article was prepared to address occupational health and safety issues in township- and village-owned enterprises (TVEs) from several aspects, including working conditions and workplace hazards, major recognized OHS problems, implications of TVE industries to environmental health, and migrant workers. Among the major recognized OHS problems, pneumoconiosis, chemical poisoning, and workplace accidents, especially in small-scale coal mines, are highlighted. It is suggested that the national polices and regulations that specifically target TVEs are indispensable and a more powerful administrative structure should be established to ensure that the pertinent polices, regulations, and OHS standards can be enforced widely and effectively in practice.

Foodborne, food related illness and role of the healthcare professionals.

Foodborne infection is a major health issue and its impact on global social and economic development remains unknown (1). A paper published in the journal Nature estimates 30% of all infections over the last 60 years were Foodborne (2). The Centre for Disease Control in the United States estimates that 76 million people per year are affected by Foodborne illness, with 300,000 requiring hospital treatment and 5000 fatalities (3). Specific foods are associated with specific Foodborne infections and food poisoning (3). Examples include unpasteurised milk (Campylobacter); shellfish (noroviruses); unpasteurized apple cider (Escherichia coli O157:H7), raw and undercooked eggs (Salmonella); fish (ciguatera poisoning); raspberries (Cyclospora); strawberries (hepatitis A virus); and ready-to-eat meats (Listeria). In clinical practice, healthcare professionals, including physicians, have to interpret clinical symptoms; enabling correct diagnosis and the differentiation of Foodborne illness from food allergy and intolerance, celiac disease, the irritable bowel syndrome, inflammatory bowel disease, viral infection and malignancy (4). An up to date understanding of diagnostic testing is fundamental to the identification of a food related illnesses. Obasanjo published a review in Medscape (5) that summarises the key aspects of the primer published in 2001 by the Foodborne Illness Primer Work Group (FIPWG) and its subsequent updates published in Morbidity and Mortality Weekly Reports (MMWR) (6). The article highlights that in routine clinical practice it is important to maintain good communication between physicians, local testing laboratories and public health authorities. The review reports that most laboratories limit stool culture to screening for species such as Salmonella, Shigella, Campylobacter jejuni or E. coli. Laboratories require advanced notification if Yersinia, Vibrio, E Coli 0157:H7 or other Campylobacter species are suspected, because additional media and incubation conditions are required. Special laboratory procedures are also required to identify infection due to parasites such as Cryptosporidium and Cyclospora cayetanensis. In practice, this means physicians need to communicate with their local laboratories to ensure that arrangements for specialist testing are in place prior to the sending of samples. Furthermore public health authorities need a close relationship with local laboratories to provide advice regarding local antibiotic sensitivities and to initiate community investigation of outbreak sources. Electronic request, information technology, eLearning, etc., have become synonyms or replacements for new and different types of communication. Although new models of communication have added a litany of words to our vocabulary and created novel ways to highlight tasks and develop plans, the way we communicate has become more complicated and potentially more confusing. Maintaining good communication is a necessity within each clinical setting and across clinical speciliaties. The paper by Obasanjo serves as a reminder that knowledge about rarer conditions can aid differential diagnosis. Specific considerations are required when investigating Foodborne infections in severely ill patients, immunocompromised patients, those with a significant travel history or in those who fail to respond to empiricial treatment. Identifying the underlying Foodborne infection may necessitate repeating stool cultures, reviewing histology results and serology. Obasanjo reminds us that physicians need be aware of unusual symptoms and signs such as rashes, myalgia, arthralgia and focal neurological weakness (5). Neurological signs such as meningism or orofacial weakness may indicate life-threatening diagnoses such as Botulism, seafood contamination, mushroom poisoning or chemical poisoning (e.g. organophosphates). The review also highlights that treatment of Foodborne microbial infections with antibiotics needs to be considered carefully and should be based upon evidence of appropriateness of treatment, antimicrobial susceptibility tests as well as interpretation of signs, symptoms and results of stool microscopy/culture. Antibiotics have no effect upon viral infections such as the common head cold and only about 5-10% of bronchitis cases are caused by a bacterial infection. Misuse and overuse of antibiotics has serious effects on public health. Antibiotic resistant bacteria are a growing threat and becoming increasingly common. Unfortunately, the low threshold of using antibiotics, in certain countries in the Middle East, might create multi-antibiotic resistant life threatening infections or "super bugs" (7). Antibiotic abuse also places the patient at unnecessary risk of adverse effects of antibiotics. Judicial use of antibiotics is therefore recommended. In conclusion, healthcare professionals play a key role in the identification and treatment of Foodborne illness. Awareness of algorithms for the correct diagnosis of food related enteropathies, good communication with testing laboratories and prompt case reporting to public health authorities are essential. Awareness on the limited benefits of antibiotics therapy should also be a priority to prevent the development of antibiotic resistant “superbugs.”

Medical toxicology: Need for recognition as a subspecialty

Medical toxicology: Need for recognition as a subspecialty

Silymarin nanoparticle prevents paracetamol-induced hepatotoxicity

Silymarin (Sm) is a polyphenolic component extracted from Silybum marianum. It is an antioxidant, traditionally used as an immunostimulant, hepatoprotectant, and dietary supplement. Relatively recently, Sm has proved to be a valuable chemopreventive and a useful antineoplastic agent. Medical success for Sm is, however, constrained by very low aqueous solubility and associated biopharmaceutical limitations. Sm flavonolignans are also susceptible to ion-catalyzed degradation in the gut. Proven antihepatotoxic activity of Sm cannot therefore be fully exploited in acute chemical poisoning conditions like that in paracetamol overdose. Moreover, a synchronous delivery that is required for hepatic regeneration is difficult to achieve by itself. This work is meant to circumvent the inherent limitations of Sm through the use of nanotechnology. Sm nanoparticles (Smnps) were prepared by nanoprecipitation in polyvinyl alcohol stabilized Eudragit RS100® polymer (Rohm Pharma GmbH, Darmstadt, Germany). Process parameter optimization provided 67.39% entrapment efficiency and a Gaussian particle distribution of average size 120.37 nm. Sm release from the nanoparticles was considerably sustained for all formulations. Smnps were strongly protective against hepatic damage when tested in a paracetamol overdose hepatotoxicity model. Nanoparticles recorded no animal death even when administered after an established paracetamol-induced hepatic necrosis. Preventing progress of paracetamol hepatic damage was traced for an efficient glutathione regeneration to a level of 11.3 μmol/g in hepatic tissue due to Smnps.

Status investigation on the reserve of antidotes in chemical poisoning emergency institutions in Guangdong

Objective To understand the status of the reserve of antidotes in chemical poisoning emergency institutions in Guangdong and to provide the basis to improve the storage.Method With the questionnaire and on-the-spot survey, the reserve of 12 kinds of antidotes in chemical poisoning emergency institutions in Guangdong were investigated.Results Within 76 institutions responsible for chemical poi-soning emergency at city, country or district levels, no one could reserve all 12 kinds of antidotes. Only 14 institutions (18.4%) had 2 to 10 kinds of the antidotes. 61 institutions (80.3%) established the links to purchase the necessary antidotes but 14 (18.4%) had neither the reserve nor the links.Conclusion The status is dissatisfied for both of the amounts and categories of the reserved antidotes are in chemical poisoning emergency institutions in Guangdong. The reserve should be supplemented immediately, especially those against the acute chemical poisonings of cyanide, sulfureted hydrogen and organophosphorous insecticide. Key words: Chemical poisoning; Emergency institution; Antidote; Investigation

The challenges experienced by Iranian war veterans living with chemical warfare poisoning: a descriptive, exploratory study

This exploratory, descriptive study investigates the experiences of Iranian war veterans living with chronic disease acquired as a result of chemical warfare. Sulphur mustard (SM) is considered one of the most important agents of chemical warfare and was widely used during the Iran-Iraq conflict in 1980-1988. There are approximately 100 000 Iranian SM casualties who suffer from serious long-term progressive health problems involving their respiratory organs, eyes and skin. Seventeen male Iranian war veterans aged between 30 and 59 years and four victims' family members participated in the study. Data was generated during individual in-depth interviews that used open-ended questions. Grounded theory techniques, including the constant comparative method of concurrent data generation and analysis, were employed in the analysis of data. Preliminary results indicate two main thematic categories: social isolation and physical disability. It is argued that a lack of knowledge about the outcomes of SM poisoning, physical restrictions and difficulty in adjusting socially decreases war veterans' functional capacity and levels of independence.

Pharmaceutical and chemical pediatric poisoning in Kuwait: a retrospective survey.

Past studies of pediatric poisoning in Kuwait have suggested differences at hospital level which could impact on the implementation of public health interventions. The objective was to compare pediatric poisoning admissions at general hospitals in Kuwait. Retrospective survey of all pediatric poisoning cases at the six general hospitals from January 2004 to December 2005. Case data were documented using ICD-10 criteria and the poisoning severity score. Aggregated data was also obtained from five private hospitals. 978 children were admitted in public hospitals over 2004 and 2005 (no fatalities) being 1.8% and 1.6% of all pediatric admissions (private hospitals admitted 293 cases). The majority of the poisoning cases came from Jahra hospital (>35%), the median age was 2.3 yrs, 93% of cases were under 6 yrs old and 71% were Kuwaiti. Two thirds of cases involved pharmaceuticals although this varied between hospitals with a tendency for more severe cases with chemical poisoning (p=0.011). Kerosene was an important problem at Jahra hospital (34.7% of chemical exposures). Non-opioid analgesics constituted 22.3% of medication exposures with hormones and drugs affecting the autonomic nervous system also common with some difference in pattern between institutions. Case demographics do not vary significantly between the hospitals but there are differences in the nature of toxic agents to which children are exposed suggesting that preventive and educational programs could be targeted to specific areas for maximal effect particularly with regard to household chemical and kerosene exposures.

Pattern of acute food, drug, and chemical poisoning in Sari City, Northern Iran

This descriptive and retrospective study was conducted at the poisoning ward of Imam teaching hospital, Sari, Iran, with the aim of evaluating the pattern of poisoning. Hence, the medical profiles of 2057 patients, who were admitted, were carefully reviewed during the period from April 2006 to March 2008 for 2 years. During this period, 2057 cases, 53.9% female and 46.1% male, were admitted with the indication of acute poisoning. The greatest proportion of poisoning occurred between the ages of 18 and 29 years, with suicidal intentions. Most cases of poisoning were intentional (85%). The most common agents involved in acute poisoning were drugs (77.7%), especially sedatives/hypnotics such as benzodiazepines, followed by opioid analgesics. Organophosphate and carbamate insecticides were the third major agent that induced poisoning. Twenty-seven patients (1.3%) who were mostly females and young adults died. Death mostly occurred due to organophosphate and carbamate insecticides (19 cases) poisoning, followed by sedatives/hypnotics like benzodiazepines (3 cases). High prevalence of intentional overdose and mortality among young adults requires considerable attention and further studies to find out the underlying causes. In addition, strict rules must be followed regarding the sale of central nervous system drugs and pesticides, particularly organophosphate and carbamate insecticides. Establishing poison information centers in different parts of the country, preparing national treatment guidelines, training healthcare providers, and ensuring easy availability of the antidotes are also recommended.

Perverse Consequences of Infrequently Culling a Pest

There are potentially many situations in which creatures will be subject to infrequent but regular culling. In terms of controlling crop pests, some farmers may only be able to afford to apply pesticides occasionally. Alternatively, pesticides may be applied only occasionally to limit their unwelcome side effects, which include pesticide resistance, chemical poisoning of agricultural workers, and environmental degradation. In terms of conservation, some species (such as the red deer in the UK) may be culled occasionally to maintain balances within their ecosystem. However, in this paper we discover, as the culmination of an exploration of adult-stage culling of a creature with juvenile and adult life stages, that, in certain circumstances, regular but infrequent culling will, perversely, increase the average population of the creature.