Size distribution effects of cadmium tellurium quantum dots (CdS/CdTe) immunotoxicity on aquatic organisms

The increasing use of products derived from nanotechnology has raised concern about their potential toxicity to aquatic life. This study sought to examine the comparative immunotoxicity of capped cadmium sulphide/cadmium telluride (CdS/CdTe) quantum dots (QDs) and possible impact of particle/aggregate size on two bivalves (Mytilus edulis and Elliptio complanata) and a fish (Oncorhynchus mykiss). The QDs were dispersed in sterile water and fractionated using a series of micro/ultrafiltration membranes of decreasing pore size: 450 nm, 100 nm, 50 nm, 25 nm, 100 kDa (6.8 nm), 30 kDa (4.6 nm), 10 kDa (3.2 nm) and 1 kDa (1.5 nm). The total concentrations of cadmium and tellurium were determined for the filtered material and for that retained on the filters (retentate). The immunotoxicity was determined by measuring cell viability and phagocytosis. Results revealed that nanoparticles retained on the ultrafilters had a higher Cd/Te ratio compared to the permeate fraction (ratio of 5 and 2 respectively) which could indicate that the CdS core was not associated with the permeable fraction of Cd. Our results demonstrate that the toxicity of CdS/CdTe QDs was concentration and size dependent. Large CdS/CdTe QD aggregates (25 nm < size < 100 nm) reduced phagocytosis more than did smaller nanoparticles (<25 nm). Moreover, our results revealed that the different species responded differently to these fractions. Mytilus edulis hemocytes were less sensitive to CdS/CdTe QDs than the Oncorhynchus mykiss macrophage and Elliptio complanata hemocytes.

Prevalence of intestinal parasites in companion animals in Ontario and Quebec, Canada, during the winter months

Veterinarians in Ontario and Quebec, Canada, typically prescribe monthly heartworm prophylactic and anthelmintic medications for use during the warm months of the year. In many patients, the use of dewormers is discontinued during the winter because of the perception that intestinal parasite infections and shedding of nematode eggs are unlikely when the weather is cold and the ground is frozen or covered with snow. This study examined fecal samples obtained from 96 shelter dogs and cats during the winter in Ontario and Quebec. Intestinal parasites were identified in 34% of submitted samples. These findings support the recommendation that veterinarians should advise pet owners to continue administration of broad-spectrum parasiticides to companion animals during the winter months.

The effect of microbial phytase and feed restriction on protein, fat and ash deposition in growing-finishing pigs

Forty-eight 35-kg-bodyweight barrows were assigned to treatments in a 2 × 2 factorial arrangement. Main factors were feed intake level (ad libitum or restricted) and supplementation of microbial phytase (with or without). Restricted pigs rece ived 80% of the feed consumed by the corresponding ad libitum group. Phytase-supplemented diets contained 584 phytase units kg-1. Body weight, fat, protein and ash were estimated every 2 wk by dual-energy X-ray absorptiometry. Plasma alpha-amino N concentrations were measured every 30 min during the 6 first postprandial hours at 90 and 132 d of age. Microbial phytase addition reduced feed intake by 6.8% (P < 0.05). Phytase did not affect (P > 0.05) feed, energy and protein efficiencies, but it reduced protein deposition (P < 0.05) and tended to reduce ADG (P < 0.09). Ninety day-old pigs receiving phytase had higher plasma levels of alpha-amino N during the first postprandial hours (P < 0.01) as compared to control pigs. At 132 d of age these effects disappeared. Supplemental phytase may improve alpha-amino acid absorption in growing pigs but the phytase effect on protein deposition suggest that these effect is not necessarily associated with better growth performance when nutrient requirements are satisfied. Key words: Pigs, phytase, feed intake, amino acids, protein deposition

Traumatic suprasellar arachnoid cyst

The case is reported of a suprasellar archnoidal cyst in a five-year-old boy who developed symptoms of hypothalamic involvement. It appears to have been of traumatic origen. It was operated upon, resulting in a remission of symptoms.

[Progressive multifocal leucoencephalopathy. Observation with predominant pontocerebellar lesions and association with congenital immune deficiency]

A young woman presented a mixed congenital and familial immunodeficiency syndrome consisting in an absence of IgA and lowered levels of IgG and IgM, with a defect in cellular immunity. She had a mild malabsorption syndrome with slight alterations of the jejunal mucosa. Non-caseating tuberculoid granulomata were found in skin lesions, in lymph nodes and in the spleen. At age 27 the patient died of a neurological disease of 4 months duration. Autopsy revealed a very widespread demyelinating process involving mainly the right cerebellar hemisphere but also most of the pons and left cerebellum, with the typical morphologic characters of PML. In the hemispheres lesions were limited to microscopical "microglial nodules" with discrete demyelination. A review of 86 published cases of PML revealed 9 other cases in which lesions showed a strong predilection for the subtentorial territories. This sampling allows for tha assumption that some 11% of the cases of PML have this particular lesion distribution. Other pertinent features of this case are briefly discussed.

[Obstructive parietal hemodissection of the intracranial vessels, a particular form of dissecting aneurysm]

A six year old girl complained of sudden severe headache, became hemiplegic and unconscious. A right carotid arteriogram revealed an obstruction of the right anterior cerebral artery and many sulvian branches. Death occurred four days later. At autopsy, a recent softening of nearly all the right middle cerebral arterial territory was found. Thrombus filled the sylvian artery and its main branches. Histologic examination of the vessel walls showed a dissecting infiltration of blood between the internal elastic lamina and the media. This particular form of dissecting aneurysm, occurring in young subjects, in the absence of atherosclerosis, high blood pressure and idiopathic medial necrosis, represents a distinct medial necrosis, represents a distinct nosologic entity that has been called "Obstructive parietal hemodissection of intracranial vessels." The pathogenesis of the disease is unknown: trauma has been mentioned, also congenital defects in the elastic lamina or other morphologic abnormalities of that lamina.

Intracranial dysgerminomas

We have reported three cases of intracranial dysgerminoma. The origin of these tumors has been controversial for a long time. It is now accepted that they develop from germ cells. The diagnosis is often difficult to confirm because of the varity of signs. If their origin is now accepted, the best way to deal with these lesions is still controversial. They can be macroscopically removed if they are in the pineal region. Such treatment is not possible for suprasellar tumors. Since these tumors can metastasize, radiation should be administered as soon as a pathological diagnosis is obtained. It is our belief that it should be administered to the whole spinal axis.

SUBENDOCARDIAL FIBROELASTOSIS IN AN ADULT WOMAN

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