Unusual nuclear inclusions in four nerve biopsies. An ultrastructural study

The authors have reported four cases where the study of peripheral nerve biopsy revealed the presence of abnormal cells in the endoneurial space. Their bulky nuclei contain in fact numerous deposits more or less tubular reminiscent of the intranuclear structures observed in the multiple sclerosis brains, and other very rare diseases. Exceptionally it seems have these images been described in peripheral nerves. It must be stressed that only one patient had an inflammatory type disease. The meaning of these images is discussed, though no definite conclusion could be reached.     

Biological Instability in a Chlorinated Drinking Water Distribution Network

The purpose of a drinking water distribution system is to deliver drinking water to the consumer, preferably with the same quality as when it left the treatment plant. In this context, the maintenance of good microbiological quality is often referred to as biological stability, and the addition of sufficient chlorine residuals is regarded as one way to achieve this. The full-scale drinking water distribution system of Riga (Latvia) was investigated with respect to biological stability in chlorinated drinking water. Flow cytometric (FCM) intact cell concentrations, intracellular adenosine tri-phosphate (ATP), heterotrophic plate counts and residual chlorine measurements were performed to evaluate the drinking water quality and stability at 49 sampling points throughout the distribution network. Cell viability methods were compared and the importance of extracellular ATP measurements was examined as well. FCM intact cell concentrations varied from 5×10³ cells mL⁻¹ to 4.66×10⁵ cells mL⁻¹ in the network. While this parameter did not exceed 2.1×10⁴ cells mL⁻¹ in the effluent from any water treatment plant, 50% of all the network samples contained more than 1.06×10⁵ cells mL⁻¹. This indisputably demonstrates biological instability in this particular drinking water distribution system, which was ascribed to a loss of disinfectant residuals and concomitant bacterial growth. The study highlights the potential of using cultivation-independent methods for the assessment of chlorinated water samples. In addition, it underlines the complexity of full-scale drinking water distribution systems, and the resulting challenges to establish the causes of biological instability.     

Protective effect of low frequency low energy pulsing electromagnetic fields on acute experimental myocardial infarcts in rats.

This series of experiments assesses the effect of exposure to low-frequency pulsing electromagnetic fields (PEMFs) in 340 rats with acute experimental myocardial infarcts. The left anterior descending artery was ligated with suture thread, and the rats underwent total body exposure to PEMFs until they were killed. Twenty-four hours after surgery, the necrotic area was evaluated by staining with triphenyltetrazolium chloride. A significant reduction of the necrotic area was observed in the animals exposed to PEMFs compared with the nonexposed controls. Exposure for up to 6 days does not appear to affect the area of necrosis, although in exposed animals an increase of vascular invasion of the necrotic area is observed: 24.3 % as against 11.3 % in controls. No effect on the necrotic area size from exposure was found when the left anterior descending artery was occluded for 60 min, followed by reperfusion. The results reported show that exposure to PEMFs is able to limit the area of necrosis after an acute ischemic injury caused by permanent ligation of the left anterior descending artery. These data are in agreement with the protective effect of PEMFs observed on acute ischemia in skin free flaps in rats and in cerebral infarcts in rabbits.     

Presence and environmental circulation of enteric viruses in three different wastewater treatment plants

Aims:  The aim of the work was to evaluate the circulation of the viruses and to determine a correlation between faecal indicators and viruses.
Methods and Results:  Raw wastewater and effluent samples were collected from three wastewater treatment plants, during three sampling periods, and analysed, using cultural and molecular methods, to determine bacteria and virus presence. The results show a removal of bacterial indicators, but a limited reduction of the phages. The viral analysis displays the circulation of cultivable enteroviruses and differences in the seasonal-geographical distribution. Hepatitis A virus was found with only two genotypes: IA-IB. Rotavirus was present in 11·11%, 24·14%, 2·78% of the samples in the 1st, 2nd and 3rd sampling periods; Astrovirus in 33·33%, 6·9%, 25%; Adenovirus in 7·41%, 3·45%, 2·78%; Norovirus in 7·41%, 10·34%, 5·56% respectively. Adenovirus was never identified in plants B and C as Rotavirus in plant C.
Conclusions:  The presence of faecal indicators was not predictive of the enteric virus presence, whereas a different circulation of Enteroviruses was found in the wastewater treatment plants.
Significance and Impact of the Study:  The study shows the importance and the usefulness of molecular methods to evaluate the virus circulation and the genetic variability of Enteroviruses.     

Usefulness and validation of a coproantigen test for dog echinococcosis screening in the consolidation phase of hydatid control in Neuquén,Argentina

Hydatidosis is endemic in Neuquén, Patagonia, Argentina, even though sanitary authorities have been performing a control programme since 1970. At present, the programme is in consolidation phase, and dogs have being evaluated by arecoline purgation. The aims of this study were to evaluate diagnostic performance of a coproantigen (CAg) ELISA test developed “in house” and to assess CAg detection in prepatent period. We examined 8 dogs experimentally infected with Echinococcus granulosus and 403 rural dogs in an endemic area in Neuquén using CAg ELISA test and arecoline purgation. Within the experimental dog group, sensitivity and specificity of the test were 93.6% and 88.5% respectively. In rural dogs group, the overall prevalence of canine echinococcosis was 3.7% using arecoline purgation and 12.4% by the CAg test; sensitivity and specificity of the test using arecoline purge as standard were 73.3% and 89.9% respectively. Possible cross reactions in CAg test were evaluated in rural dogs: CAg was undetectable in 96.4% of the dogs infected only with taeniids non-E. granulosus, and in 90.1% of dogs infected with non-taeniid helminths. The CAg test could detect infections within prepatent period and produced negative results after worm expulsion. Our test showed adequate diagnostic performance with experimentally and naturally infected dogs, in the epidemiological situation of Neuquén. Employment of this sensitive and practical method for surveillance in the control programme in Neuquén would improve screening of canine echinococcosis by detecting infected dogs even with low burdens or within prepatent period.     

Molecular characterization of Echinococcus isolates indicates goats as reservoir for Echinococcus canadensis G6 genotype in Neuquén, Patagonia Argentina

Human cystic echinococcosis is a highly endemic zoonotic disease in the province of Neuquén, Patagonia Argentina, although a hydatid control programme has been carried out since 1970. Human infection due to Echinococcus canadensis (G6 genotype) is frequent in Neuquén. However, the reservoir for this species remains undetermined in a region where camels are absent. We investigated the fertility, viability and molecular epidemiology of hydatid cysts obtained from local goats, pigs and sheep in order to identify the possible reservoirs of E. canadensis (G6). We also analyzed isolates from infected dogs. A total of 67 isolates were identified by the DNA sequencing of the mitochondrial cytochrome c oxidase subunit 1 gene. Cysts from sheep (n = 16), goats (n = 23) and pigs (n = 18) and adult worms from 10 infected dogs were analyzed. The fertility of the hydatid cysts was 78.6%; 90.4% and 94.4% for sheep, goats and pigs, respectively. We detected E. canadensis (G6) in 21 of 23 goat samples and in 1 dog isolate, E. canadensis (G7) in all the pig isolates, E. granulosus sensu stricto (G3) in 1 sheep and the G1 genotype in 15 sheep, 2 goats and 9 dog samples. The G1 haplotypes included the common sheep strain sequence and 2 microvariants of this sequence. E. granulosus sensu stricto (G3) is described for the first time in South America. We conclude that goats act as reservoir for E. canadensis (G6) in Neuquén, and that control strategies may have to be adapted to local molecular epidemiology to improve the control of parasite transmission.