Improvement in survival after paraquat ingestion following introduction of a new formulation in Sri Lanka

BACKGROUND

Pesticide ingestion is a common method of self-harm in the rural developing world. In an attempt to reduce the high case fatality seen with the herbicide paraquat, a novel formulation (INTEON) has been developed containing an increased emetic concentration, a purgative, and an alginate that forms a gel under the acid conditions of the stomach, potentially slowing the absorption of paraquat and giving the emetic more time to be effective. We compared the outcome of paraquat self-poisoning with the standard formulation against the new INTEON formulation following its introduction into Sri Lanka.

METHODS AND FINDINGS

Clinical data were prospectively collected on 586 patients with paraquat ingestion presenting to nine large hospitals across Sri Lanka with survival to 3 mo as the primary outcome. The identity of the formulation ingested after October 2004 was confirmed by assay of blood or urine samples for a marker compound present in INTEON. The proportion of known survivors increased from 76/297 with the standard formulation to 103/289 with INTEON ingestion, and estimated 3-mo survival improved from 27.1% to 36.7% (difference 9.5%; 95% confidence interval [CI] 2.0%-17.1%; p = 0.002, log rank test). Cox proportional hazards regression analyses showed an approximately 2-fold reduction in toxicity for INTEON compared to standard formulation. A higher proportion of patients ingesting INTEON vomited within 15 min (38% with the original formulation to 55% with INTEON, p < 0.001). Median survival time increased from 2.3 d (95% CI 1.2-3.4 d) with the standard formulation to 6.9 d (95% CI 3.3-10.7 d) with INTEON ingestion (p = 0.002, log rank test); however, in patients who did not survive there was a comparatively smaller increase in median time to death from 0.9 d (interquartile range [IQR] 0.5-3.4) to 1.5 d (IQR 0.5-5.5); p = 0.02.

CONCLUSIONS

The survey has shown that INTEON technology significantly reduces the mortality of patients following paraquat ingestion and increases survival time, most likely by reducing absorption.

Self-poisoning in rural Sri Lanka: small-area variations in incidence

Background

Self-poisoning is one of the most common methods of suicide worldwide. The intentional ingestion of pesticides is the main contributor to such deaths and in many parts of rural Asia pesticide self-poisoning is a major public health problem. To inform the development of preventive measures in these settings, this study investigates small-area variation in self-poisoning incidence and its association with area-based socioeconomic and agricultural factors.

Methods

Ecological analysis of intentional self-poisoning in a rural area (population 267,613) of Sri Lanka in 2002. The geographic distribution of cases was mapped to place of residence. Using administrative division (GN), median population size 1416, as unit of analysis, associations with socioeconomic and agricultural indicators were explored using negative binomial regression models.

Results

The overall incidence of intentional self-poisoning in the study area was 315 per 100,000 (range: 0 – 2168 per 100,000 across GNs). Socioeconomic disadvantage, as indexed by poor housing quality (p = 0.003) and low levels of education (p < 0.001) but not unemployment (p = 0.147), was associated with a low self-poisoning incidence. Areas where a high proportion of the population worked in agriculture had low overall levels of self-poisoning (p = 0.002), but a greater proportion of episodes in these areas involved pesticides (p = 0.01). An association with extent of cultivated land was found only for non-pesticide poisoning (p = 0.01).

Conclusion

Considerable small-area variation in incidence rates of intentional self-poisoning was found. The noteworthy concentration of cases in certain areas and the inverse association with socioeconomic deprivation merit attention and should be investigated using individual-level exposure data.

Long-term event-related potential changes following organophosphorus insecticide poisoning

OBJECTIVE

To determine prolonged effects of organophosphorus (OP) insecticide poisoning on cognitive event-related potentials (ERPs).

METHODS

ERPs of a group of 32 patients recovered from cholinergic phase of OP insecticide poisoning were compared with those of two matched control groups: 32 healthy volunteers and nine patients hospitalised with paracetamol overdose. A follow-up assessment was done in 21 patients (66% of the initial sample) 6 months after OP intoxication and the findings were compared with their initial ERP data.

RESULTS

Patients showed highly significant prolongation of P300 latency, compared to healthy controls (p=0.003) and the controls with paracetamol overdose (p=0.016). Follow-up ERP findings of the patients revealed that this impairment remained unchanged even 6 months after OP poisoning (p=0.790). There was no significant difference in N100, P200 and N200 latencies or P300 amplitude either among the groups or between the two assessments of the patients with OP poisoning.

CONCLUSIONS

Our results suggest that acute OP poisoning causes a delay in cognitive processes involved in stimulus classification, lasting at least for 6 months.

SIGNIFICANCE

These findings highlight the possibility of development of long-lasting cognitive deficits following OP insecticide poisoning, and warrant longer-term prospective studies to determine whether this impairment is permanent.

Cognitive processing of visual stimuli in patients with organophosphate insecticide poisoning

OBJECTIVE

To determine the effect of organophosphate (OP) insecticide poisoning on cognitive processing time of visual stimuli.

METHODS

We compared 33 patients who recovered from the cholinergic phase (on average, 15 days after poisoning) with an age- and sex-matched control group. The tests used were simple visual reaction time (SVRT), recognition visual reaction time (RVRT), visual evoked potentials (VEP), and motor evoked potentials (MEP). The term cognitive processing time (CPT) was used to denote the time taken from the initial cortical perception of a stimulus to initiation of the descending motor impulse. CPT of each type of visual reaction was calculated by subtracting the sum of the visual impulse duration and the motor impulse duration from reaction time (CPT = reaction time-[P100 latency + total motor conduction time]).

RESULTS

Both the SVRT and RVRT were significantly prolonged in patients. There was no significant difference in P100 latency or total motor conduction time (TMCT) between patients and the controls. However, CPT of simple visual reactions (CPT(SVR)) and the CPT of recognition visual reactions (CPT(RVR)) were significantly prolonged in patients.

CONCLUSIONS

Acute organophosphate poisoning may slow higher-order cognitive processing involved in visual stimulus detection and visual stimulus discrimination, even after clinical recovery from the cholinergic phase.

Evaluation of hybrid processes for nitrification by comparing MBBR/AS and IFAS configurations

An integrated fixed-film activated sludge (IFAS) pilot plant and a moving bed biofilm reactor coupled with an activated sludge process (MBBR/AS) were operated under different temperatures, carbon loadings and solids retention times (SRTs). These two types of hybrid systems were compared, focusing on the nitrification capacity and the nitrifiers population of the media and suspended biomass alongside other process performances such as carbonaceous and total nitrogen (TN) removal rates. At high temperatures and loadings rates, both processes were fully nitrifying and achieved similarly high carbonaceous removal rates. However, under these conditions, the IFAS configuration performed better in terms of TN removal. Lower temperatures and carbon loadings led to lower carbonaceous removal rates for the MBBR/AS configuration, whereas the IFAS configuration was not affected. However, the nitrification capacity of the IFAS process decreased significantly under these conditions and the MBBR/AS process was more robust in terms of nitrification. Ammonia oxidising bacteria (AOB) and nitrite oxidising bacteria (NOB) population counts accurately reflected the changes in nitrification capacity. However, significantly less NOBs than AOBs were observed, without noticeable nitrite accumulation, suggesting that the characterisation method used was not as sensitive for NOBs and/or that the NOBs had a higher activity than the AOBs.

Mass public health programmes and the obligations of sponsoring and participating organisations

The obligations of organisations associated with policy formation and implementation of international mass public health programmes are explored. Lines of responsibility are considered to become unclear because of the large number of agencies associated with such programmes. A separation of the relevant obligations among the bodies responsible for the formulation (usually an international non-governmental organisation) and those responsible for the implementation of the policies (usually national bodies) is suggested. The continuing oral polio vaccine campaign against poliomyelitis in India is used to illustrate the general argument. Although the aim of the programme is legitimate and laudable, unnecessary harm is currently being caused to some children as a result of elements of the policy and this should be rectified immediately. Such mass programmes should take care to ensure that people are not unnecessarily sacrificed in the drive to attain the desirable ends of the policy.

Screening oocytes by polar body biopsy

Preimplantation genetic aneuploidy screening performed by polar body biopsy has become a frequently used method, especially as in several countries only preconceptional genetic diagnosis is allowed. To penetrate the zona pellucida, mechanical, chemical and laser-assisted techniques have been introduced. In this paper, the advantages, disadvantages, efficacy and safety of these techniques are elucidated.

The Sydney riots

This article describes the recent Sydney riots and the commentary surrounding them. The author demonstrates how, through processes of ‘analytical et nic cleansing’, ‘ethnic homogenization and specification’, and ‘blame displacement’, the Lebanese Muslim community, a target of the initial rioters, came to be victimized in commentary on the riots. While the riots may not have been particularly significant in themselves, the commentary surrounding them provides an important window onto the state of cultural politics in Australia at a specific juncture in time when multi-culturalism is simultaneously hegemonic but subject to attack from Australia’s ruling federal political regime. The author claims, moreover, that the victimization of Lebanese Muslims is indicative of a particular current process in which a discourse of multi-culturalism, engendered largely by its liberal advocates and drawing on the scholarly works of anthropologists and other social scientists, is utilized to undermine multi-culturalism as a form of social policy and organization.

IGF-I and epidermal growth factor levels in follicular fluid of women undergoing controlled ovarian hyperstimulation using the multidose GnRH-antagonist protocol or the long GnRH-agonist protocol

The intrafollicular levels of IGF-I and epidermal growth factor (EGF) were studied in women undergoing controlled ovarian hyperstimulation using the multidose GnRH-antagonist protocol or the long agonist protocol, in an attempt to elucidate whether GnRH-antagonists affect the levels of the two growth factors. The follicular fluid concentration of IGF-I, EGF, estradiol and progesterone were detected in 68 women undergoing ovarian hyperstimulation for intracytoplasmic sperm injection (ICSI) cycles. There were no differences in intrafollicular concentrations of EGF and IGF-I in the two studied groups. Additionally, we found no correlation between the intrafollicular levels of IGF-I or EGF and the ICSI outcome. The intrafollicular levels of IGF-I were positively correlated with those of progesterone. In conclusion, the intrafollicular levels of IGF-I and EGF do not seem to be influenced by the stimulation protocol. The intrafollicular levels of both growth factors can not serve as prognostic markers for the ICSI outcome.

In defence of moral imperialism: four equal and universal prima facie principles

Raanan Gillon is a noted defender of the four principles approach to healthcare ethics. His general position has always been that these principles are to be considered to be both universal and prima facie in nature. In recent work, however, he has made two claims that seem to present difficulties for this view. His first claim is that one of these four principles, respect for autonomy, has a special position in relation to the others: he holds that it is first among equals. We argue that this claim makes little sense if the principles are to retain their prima facie nature. His second claim is that cultural variation can play an independent normative role in the construction of our moral judgments. This, he argues, enables us to occupy a middle ground between what he sees as the twin pitfalls of moral relativism and (what he calls) moral imperialism. We argue that there is no such middle ground, and while Gillon ultimately seems committed to relativism, it is some form of moral imperialism (in the form of moral objectivism) that will provide the only satisfactory construal of the four principles as prima facie universal moral principles.

Derivation of the Tumour Control Probability (TCP) from a Cell Cycle Model

In this paper, a model for the radiation treatment of cancer which includes the effects of the cell cycle is derived from first principles. A malignant cell population is divided into two compartments based on radiation sensitivities. The active compartment includes the four phases of the cell cycle, while the quiescent compartment consists of theG0state. Analysis of this active-quiescent radiation model confirms the classical interpretation of the linear quadratic (LQ) model, which is that a larger α/β ratio corresponds to a fast cell cycle, while a smaller ratio corresponds to a slow cell cycle. Additionally, we find that a large α/β ratio indicates the existence of a significant quiescent phase. The active-quiescent model is extended as a nonlinear birth–death process in order to derive an explicit time dependent expression for the tumour control probability (TCP). This work extends the TCP formula from Zaider and Minerbo and it enables the TCP to be calculated for general time dependent treatment schedules.

Use of neostigmine for the management of drug induced ileus in severe poisonings

INTRODUCTION

Effective whole bowel irrigation may be difficult in the presence of drug-induced ileus. Neostigmine, which inhibits the enzymatic degradation of acetylcholine, has been suggested to improve drug-induced ileus. We present two poisoning cases in which neostigmine was used to facilitate gut decontamination complicated by ileus.

CASE REPORTS

A 47-year-old woman, after overdose with sodium valproate, venlafaxine, and ibuprofen, developed ileus that prevented whole bowel irrigation. Neostigmine, 2.5 mg intravenously followed by 1.25 mg three hours later, led to improved bowel transit and successful whole bowel irrigation. A 25-year-old man developed ileus after overdose with venlafaxine, dothiepin, and ethanol. Neostigmine administration led to improved intestinal motility and successful whole bowel irrigation.

DISCUSSION

We demonstrate facilitated gut decontamination temporally associated with administration of neostigmine in two patients judged to have drug-induced ileus following overdose. No significant adverse events related to neostigmine were observed.

The epidemiology of left ventricular hypertrophy in type 2 diabetes mellitus

AIMS/HYPOTHESIS

Patients with type 2 diabetes mellitus are at greater cardiovascular risk than the general population. Although it is widely acknowledged that diabetes is a risk factor for coronary artery disease, the increased prevalence of potentially lethal left ventricular abnormalities in this population is less well appreciated.

METHODS

We carried out an echocardiographic study of 500 subjects with type 2 diabetes mellitus to assess the prevalence of left ventricular hypertrophy (LVH) and left ventricular systolic dysfunction (LVSD). We also assessed whether abnormalities in diastolic filling parameters were present.

RESULTS

Of the 371 patients in whom left ventricular mass could be successfully assessed, 264 had LVH (71%). Left ventricular systolic dysfunction was much less common, being present in 16/385 patients (4.2%). Long axis contraction was abnormal in 29/429 patients (6.8%). Diastolic filling abnormalities were present in 178/435 (41%) of patients who could be classified using the selected criteria.

CONCLUSIONS

We conclude that left ventricular abnormalities are common in type 2 diabetic patients. As medical therapy is available for both LVH and LVSD and has been demonstrated to reduce cardiovascular death, these left ventricular abnormalities could be ideal targets for screening, followed by selective therapeutic intervention.

What is the role of the research ethics committee? Paternalism, inducements, and harm in research ethics

In a recent paper Edwards, Kirchin, and Huxtable have argued that research ethics committees (RECs) are often wrongfully paternalistic in their approach to medical research. They argue that it should be left to competent potential research subjects to make judgments about the acceptability of harms and benefits relating to research, and that this is not a legitimate role for any REC. They allow an exception to their overall antipaternalism, however, in that they think RECs should have the power to prohibit the use of financial inducements to recruit research subjects into trials. In this paper it is argued that these claims are unjustified and implausible. A sketch is provided of an alternative model of the role of the REC as an expert body making judgments about the acceptability of research proposals through a consensual weighing of different moral considerations.