Malaria in camps for internally-displaced persons in Uganda: evaluation of an insecticide-treated bednet distribution programme

Malaria is a key health problem among displaced populations in malaria-endemic areas. Mass distribution of insecticide-treated bednets (ITN) to prevent malaria is often carried out in complex emergencies, but there are few data on the outcome or operational effectiveness of such programmes. In June 2001, Medecins Sans Frontieres completed a mass distribution of ITNs (Permanet) to internally displaced persons in Bundibugyo, southwest Uganda, distributing one to four nets per household, and aiming to provide coverage for all residents. In July 2002, we did a cross-sectional survey using three-stage cluster sampling to evaluate the programme. A total of 1245 individuals from 835 households were interviewed. An ITN was present in 75.6% (95% CI 72.7-78.5) of the households, but only 56.5% (95% CI 52.3-60.4) of individuals were sleeping under an ITN, and nets were often damaged. The prevalence of malarial parasitaemia was 11.2% (95% CI 9.4-13.0), and was significantly lower in ITN users compared to non-users (9.2% vs. 13.8%, relative risk [RR] 0.63, 95% CI 0.46-0.87); ITNs with severe damage remained effective (RR for severely damaged net 0.58, 95% CI 0.35-0.98). There was no significant difference in haemoglobin concentration between ITN users and non-users.     

Prescribed and reported drug use during pregnancy

Few studies describe drug utilization in pregnancy focusing on prescribing practices. This study is part of a larger survey on perinatal care in the City of Rio de Janeiro, Brazil. The type of hospital (public, contracted out by the Unified National Health System, or private) determined the stratification of 10,072 hospitalized post-partum women, who were asked about medication used during pregnancy. Hospital records supplied information on drugs prescribed during labor. Drugs were classified according to the Anatomical Therapeutic Chemical (ATC) system. Another system was used for specific cases of referred use. A mean of 2.08 drugs was prescribed during labor, and a mean of 2.3 was reported during pregnancy. Anesthetics, antibiotics, oxytocin, and analgesics were the most frequently prescribed during labor, with significant differences between strata. Ferrous sulfate, vitamins, scopolamine, and acetaminophen were the main drugs reported during pregnancy. Women who had attempted abortion referred use of various kinds of tea (49.7%) and misoprostol (9.2%). The drug utilization pattern was consistent with the literature. This study offers knowledge on prescribing patterns during labor and self-reported use during pregnancy in both the public and private sectors.     

Caring for children and adolescents with cancer: the intrathecal chemotherapy phase

This study aims to explore the experiences of children and adolescents with cancer during the intrathecal chemotherapy phase, by means of a qualitative approach. Empirical data were collected on the basis of semi-structured interviews. Study participants were eleven children/adolescents who received intrathecal chemotherapy, between 07 and 16 years old, from both genders, attended at a hospital school in the interior of S?o Paulo State, Brazil. Results converged towards the following issues: intrathecal routine; fear, pain and relief fantasies and strategies. This study gave access to important information with a view to caring for children/adolescents during the intrathecal chemotherapy phase, which is considered as one of the most stressing situations. With respect to nursing implications, we identified the vital nature of information for children/adolescents with cancer since this makes it possible to minimize uncertainties and negative feelings and makes them collaborate and participate in treatment.     

Dengue prevention and control: a review of studies on knowledge, beliefs, and practices

This article aims to contribute to dengue control programs through a review of recent studies on knowledge, beliefs, and practices concerning dengue and dengue prevention. The results show that adequate knowledge of dengue and prevention methods are found in close association with high rates of domiciliary infestation by Aedes aegypti. This suggests that traditional education strategies, although efficient in transmitting information, have failed to change population behavior. Qualitative studies reveal two important issues that appear to explain these attitudes: representations of dengue and risks associated with mosquitoes and difficulties in avoiding infestation of household water recipients due to sanitation problems in communities.     

Biochemical changes in the kidneys after perinatal intoxication with lead and/or cadmium and their antagonistic effects when coadministered

Lead acetate (300 mg/L) and/or cadmium acetate (10 mg/L) were administered as drinking water to pregnant Wistar rats from day 1 of pregnancy to parturition (day 0) or until weaning (day 21) to investigate the possible nephrotoxic effects of these metals. We also studied the possibility of toxicological interactions between both metals. Kidneys were used to determine the activity of several enzymes considered key to correct renal function: alkaline and acid phosphatases, Mg(2+)/Ca(2+)-dependent ATPase, and Na(+)/K(+)-dependent ATPase. The results showed a general decrease in the activity of these enzymes after treatment with the heavy metals; this fact suggests that lead and cadmium are able to impair renal function due to biochemical alterations, since ATPases are essential for reabsorption and secretion processes and phosphatases are involved in the differentiation of the proximal tubules. On the other hand, simultaneous perinatal administration of both metals seems to protect against the toxicity produced by cadmium or lead separately. It is not clear whether this is due to decreased absorption or increased sequestration or excretion.     

Anterior segment inflammation and hypotony after posterior segment surgery

Recent advances in the instrumentation and surgical techniques for posterior segment surgery permit better anatomic and functional outcomes. Nevertheless, these procedures may be associated with complications involving the anterior segment, including postoperative inflammation and hypotony. One must differentiate infectious from noninfectious inflammation to initiate appropriate therapy promptly. Hypotony is a frustrating problem because it is difficult to reverse. The exclusion of eyes with other known causes of hypotony is important before establishing the putative mechanism of tractional ciliary body detachment caused by epiciliary proliferative tissue.     

Enhancement of purinergic neurotransmission by galantamine and other acetylcholinesterase inhibitors in the rat vas deferens

Galantamine, a mild acetylcholinesterase inhibitor and an allosteric ligand of nicotinic receptors, enhanced in a concentration-dependent manner the amplitude of purinergic twitch contractions of the electrically stimulated rat vas deferens (0.2 Hz, 1 ms, 60 V). Other acetylcholinesterase inhibitors also increased the twitches, showing a hierarchy of potencies of galantamine>physostigmine>tacrine>rivastigmine=donepezil. The potentiations seem to be unrelated to the ability to inhibit acetylcholinesterase, since the hierarchy of potencies to block the enzyme in vas deferens was tacrine>physostigmine>rivastigmine>donepezil>galantamine. Acetylcholine also increased the twitches; such effect was produced by a low range of concentrations of acetylcholine (10(-10)-10(-7) M). This facilitatory effect of acetylcholine on twitches was significantly potentiated by galantamine (10(-7)-10(-6) M), but not by rivastigmine or donepezil. A striking enhancement of twitches was also caused by charybdotoxin, a blocker of high-conductance Ca2+-activated K+ channels, and by 4-aminopyridine, a non-specific blocker of K+ channels; in addition, apamin, a blocker of small-conductance Ca2+-activated K+ channels, induced a lower potentiation. The antagonist mecamylamine (10(-7)-10(-6) M) reduced by 80% the potentiation by galantamine, indicating the involvement of nicotinic receptors. Therefore, it is suggested that, besides an inhibition of acetylcholinesterase, some additional mechanisms, such as blockade of Ca2+-dependent K+ channels, or activation of nicotinic receptors of nerve terminals, might be involved in twitch potentiation. These results are relevant in the context of the clinical use of galantamine to improve cognition and behaviour in patients with Alzheimer's disease.     

The sigma<Subscript>1</Subscript> (σ<Subscript>1</Subscript>) receptor activation is a key step for the reactivation of cocaine conditioned place preference by drug priming

Rationale Cocaine-seeking behavior can be investigated in rodents using the conditioned place preference (CPP) paradigm, in which the drug-paired environment serves as a conditioned stimulus. Such approach allowed to previously demonstrate the importance of the neuromodulatory sigma₁ (₁) receptor in acquisition of cocaine-induced CPP. CPP can be extinguished and then reactivated, notably using a cocaine challenge (i.e., priming).Objectives and methods In order to examine the role of the ₁ receptor in reinstatement of Cocaine-seeking, Swiss mice acquired CPP with cocaine (30 mg/kg, ip) and then CPP was extinguished.Results A challenge cocaine priming (15 mg/kg) reactivated CPP up to 140% of the post-conditioning response. Pre-administration of the ₁ receptor antagonist BD1047 (330 mg/kg, ip) or repeated treatment with an antisense probe targeting the ₁ receptor prevented CPP reactivation. The ₁ agonist igmesine (1–10 mg/kg, ip) or the steroid dehydroepiandrosterone (DHEA, 10–40 mg/kg, sc) reactivated CPP, in a BD1047-sensitive manner. Moreover, the in vivo [³H](+)-SKF-10,047 binding levels to the ₁ receptor were increased after cocaine conditioning in numerous brain structures and these increases subsisted after extinction. Finally, cross-reactivation of cocaine-induced CPP was observed after phencyclidine (PCP), morphine, nicotine and ethanol administration. However, BD1047 blocked reactivation of CPP induced by PCP, morphine and nicotine but not ethanol.Conclusions Since activation of the ₁ receptor is not sufficient to sustain CPP in naive animals [Neuropsychopharmacology 26 (2002) 444], it is concluded that ₁ receptor activation is a key event for relapse to drug seeking. Activation may occur via sensitization due to enhanced in vivo available of receptors.     

Toxicity assessment of complex mixtures remains a goal

One of the initial steps in remediating contaminated environments is to assess the human and ecological health risk associated with exposure to contaminants in a specific medium. Presented here are the results of a five-year study investigating the toxicity of simple and complex mixtures. A series of model compounds and simple mixtures including polycyclic aromatic hydrocarbons (PAHs), pentachlorophenol (PCP), and halogenated aliphatic hydrocarbons (HAHs) were analyzed. Mixture toxicity was studied using microbial genotoxicity assays and cytotoxicity assays with renal and neural cells. The majority of binary mixtures described here induced additive responses. A limited number of samples were identified where binary mixtures induced inhibitory effects. For example, benzo(a)pyrene (BAP) alone induced 30% renal cell death, whereas an equimolar dose of chrysene and BAP only produced 1.6% cellular death. In none of the mixtures tested did the mixture toxicity results deviate from the predicted results by an order of magnitude. The results from testing binary mixtures in this study indicate that the results did not deviate significantly from additivity. Complex mixture results were more difficult to interpret. The toxicity of complex mixtures could not be accurately predicted based on chemical analysis. This could be due to chemical interactions or due to the presence of unidentified chemicals, such as alkyl PAHs or high molecular weight PAHs that are not included in the standard risk assessment procedure. Even though the results from these in vitro studies indicate that additive assumptions will generally be appropriate for binary mixtures similar to the ones tested here, the risk associated with complex mixtures remains a challenge to predict. Before the results of toxicity testing can be used to adjust risk assessment calculations, it is important to fully appreciate the chemical composition and to understand the mechanism of observed chemical interactions in animals chronically exposed to low doses of chemical mixtures. This research was supported by ATSDR Grant no. ATU684505 and NIEHS SBRP Grant no. P42 ES04917.