Permissible Concentrations of Arsenic and Lead in Soils Based on Risk Assessment

Establishing permissible concentrations for As and Pb in soils is of practical importance because of toxicity of these metals, their widespread contamination, and limited resources available for remediation of contaminated soils. The USEPA pathway approach to risk assessment was used to assess an environmental hazard related to As and Pb in soils and to evaluate safe concentrations of these metals in contaminated soil. The results from large-scale field experiments with soil fly ash-biosolids blends were used as input data to analyze pathways of the most intense transfer of the contaminants to a target organism. A direct soil ingestion by children (the soil-human pathway) was considered the most important exposure route to soil As and Pb. A conservative risk analysis shows that As concentrations in soil can reach 40 μg g^-1 without a hazard to exposed organisms. A Pb concentration in soil up to 300 μg g^-1 does not cause an excessive intake of Pb by humans as evaluated by a direct soil ingestion exposure model.     

Micromorphology and topography of tarsal joint capsule's vascular elements in cats and dogs

Both cats and dogs belong to animals with the same type of limb support but have different nature of movement. Despite belonging to digitigrade animals, cats and dogs have a different nature of motion. While moving, the medial joint surface in cats and lateral surface in dogs carry the larger pressure. The aim of the study was to compare the similar surfaces of the cat's and dog's tarsal joint capsule and to detect differences in its histostructure and vascularisation. For the study, we used the capsule of the tarsal joint of five cats and five dogs dissected with accordance to anatomical surfaces. Sections of the capsule joint were stained with haematoxylin–eosin. The sections were examined with a microscope at magnification ×250 and ×400. The statistical analysis of the results was done using Student's t test. During the research, a difference in histostructure and vascularisation of tarsal joint capsule in cats and dogs on respective surfaces were found. The medial surface of the tarsal joint capsule was the most saturated with hemomicrocirculatory bed structures in cats, whereas this was the lateral surface in dogs. The most active metabolic processes also take place in these areas of the joint capsule, which is important to know when prescribing therapeutic procedures and determining an optimal surgical access.     

6beta-hydroxygedunin from Azadirachta indica. Its potentiation effects with some non-azadirachtin limonoids in neem against lepidopteran larvae

The biological activity of 6beta-hydroxygedunin isolated from Azadirachta indica A. Juss. was assessed using the gram pod borer, Helicoverpa armigera (Hubner), and Asian armyworm, Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), alone and in combination with other limonoids, gedunin, salannin, nimbinene, and azadirachtin. The compound exhibited growth inhibitory activity in artificial diet bioassays, with 24.2 and 21.5 ppm, respectively, inhibiting growth by 50%. This efficacy was higher in comparison to gedunin (EC(50) = 50.8 and 40.4 ppm), salannin (EC(50) = 74.5 and 72.0 ppm), and nimbinene (EC(50) = 391.4 and 404.5 ppm). Azadirachtin, however, remained the most active neem allelochemical against both insect species. Nutritional assays clearly demonstrated that, though relative consumption and growth rates of fourth instar larvae were reduced, gedunin-type compounds induced physiological toxicity, evident by reduced efficiency of conversion of ingested food (ECI) in feeding experiments. Salannin and nimbinene, on the contrary, induced concentration-dependent feeding deterrence only. In feeding experiments, combinations of the compounds revealed that when azadirachtin was present in a mixture, EC(50) values did not deviate from the individual efficacy of azadirachtin (0.26 and 0.21 ppm, respectively) against H. armigera and S. litura larvae. However, a combination without azadirachtin did show a potentiation effect with potent EC(50) values among structurally different molecules, i.e., when salannin or nimbinene was combined with 6beta-hydroxygedunin or gedunin rather than structurally similar salannin + nimbinene or 6beta-hydroxygedunin + gedunin. Obviously, azadirachtin being the most active compound in neem is not synergized or influenced by any other limonoid, but other non-azadirachtin limonoids were more potent in specific combinations vis-à-vis the structural chemistry of the compound. It is obvious from the present study that potentiation among non-azadirachtin limonoids having explicitly two different modes of action, such as feeding deterrence and physiological toxicity, may be playing a significant role in the potentiation effect.     

Forms of Cu,Ni, and Zn in soils of sudbury,ontario and the metal concentrations in plants

Forms of Cu, Ni, and Zn in the contaminated soils of the Sudbury mining/smelting district were studied to assess metal mobility and plant availability. Soil, tufted grass (Deschampsia caespitosa (L.) Beauv.), tickle grass (Agrostis scabra Willd.), dwarf birch (Betula pumila L. var. glandulifera Regel) and white birch (Betula paprifera Marsh.) leaf and twig samples were taken from 20 locations around three Cu-Ni smelters. The sampling sites were collected to cover a wide range of soil pH and soil Cu and Ni concentrations. The water-soluble, exchangeable, sodium acetate-soluble, and total concentrations of the metals in the soils were analyzed. The soils were contaminated with Cu and Ni up to 2000 µg g^?1. Zinc concentrations were also elevated in some samples above the normal soil level of 100 µg g^?1. The mobility of Cu and Zn, expressed as the proportion of metals in Fl and F2 forms, increased with soil pH decrease. A strong positive correlation was found between the soil exchangeable (F2) Ni and the soil pH. Concentrations of Cu and Ni in birch twigs showed a good linear relationship with exchangeable forms of the metals in soils. A highly significant correlation was also found between total Ni in soils and the metal content of the twigs. No significant correlation was found between Zn concentrations in the soils and plants. Birch twigs are a good indicator (better than leaves) of Cu and Ni contamination of the Sudbury soils. The mobile forms of Cu and Ni and low pH seem to be the main factors that will control the success of revegetation. Strong variability of the soil metal mobility requires any reclamation effort be site-specific.     

Genetic aspects of some carotenoids synthesis in tomatoes

Summary The wild species of tomato,Lycopersicon minutum, carries a factor which after introduction into cultivated varieties ofL. esculentum results in an increasing concentration of -carotene in fruits. The factor is closely linked to the sp⁺ gene in chromosome 6 (0.12 % c.o.). This allows to conclude that it is either the B gene or a very similar allele. (The fruit flesh ofL. minutum is greenish white and contains very small quantities of carotenoids; this is perhaps due to the absence of the r⁺ gene). The results of the present study and findings of other workers suggest that the gene B occurs in all species of the genusLycopersicon and only a part ofL. esculentum and a part ofL. pimpinellifolium are the exceptions in having the allele B+.Some segregants characterised by remarkably increased amount of both -carotene and lycopene have been isolated from the cross between high -carotene line and the hp mutant.

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Zusammenfassung Die WildtomateLycopersicum minutum enthält einen Faktor, der, auf KulturtomatenL. esculentum übertragen, eine beträchtliche Zunahme des Gehaltes an -Carotin in den Früchten verursacht. Dieser Faktor ist eng verbunden mit dem sp⁺-Gen im 6. Chromosom (0,12 % c.o.). Dies läßt vermuten, daß es entweder das B-Gen oder ein sehr ähnliches Allel ist. (Die Früchte vonL. minutum haben grünlich-weißes Fleisch und enthalten sehr kleine Mengen von Karotinoiden; das hängt höchstwahrscheinlich mit der Abwesenheit des r⁺-Gens zusammen). Auf Grund von eigenen Arbeiten und Arbeiten anderer Autoren kann man vermuten, daß das B-Gen in allen Arten der GattungLycopersicum anwesend ist und nur einige Varietäten vonL. esculentum undL. pimpinellifolium ausnahmsweise das B+-Allel besitzen.Als Ergebnis einer Kreuzung zwischen der Linie mit erhöhtem Gehalt an -Carotin und den Mutanten hp hat man Segreganten erhalten, welche sich durch einen erhöhten Gehalt sowohl an -Carotin wie an Lykopin auszeichnen.

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Résumé Une espèce de tomate sauvage,Lycopersicon minutum, contient un facteur qui — après avoir été introduit dans les variétés cultivées — détermine un taux élevé de -carotene dans les fruits. Ce facteur est étroitement associé avec le gène sp⁺ du chromosome 6 (0.12 % c.o.), ce qui permet de supposer qu'il s'agit ou bien du gène B ou d'un allèle très ressemblant. (La pulpe du fruitL. minutum est d'un blanc verdâtre et contient de très petites quantités de caroténoides, peutêtre à cause de l'absence du gène r⁺). Il résulte de cette étude ainsi que des données puisées dans d'autres, qu'on peut supposer que le gène B se trouve dans toutes les espèces du genreLycopersicon et seulement une partie de l'espèceL. esculentum et une partie de l'espèceL. pimpinellifolium sont des exceptions qui possèdent l'allèle B+.Par croisement entre la lignée enrichie de -carotene et le mutant hp, on a obtenu des ségrégants caractérisés par une plus forte concentration aussi bien de -caroténe que de lycopène.

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Paper read in Lund, Sweden (EUCARPIA-CIQ Congress, 14th to 17th July 1965) on 17/7/1965.     

Effects of sarcoptic mange on lactating swine and growing pigs

The impact of Sarcoptic mange on sows and on performance of their offspring from birth to slaughter was determined. Sows naturally infested with Sarcoptic mange were paired, mated to the same boar, and assigned randomly to treated or control farrowing groups. Treated sows received ivermectin s.c. at 300 micrograms/kg body weight; control sows received the vehicle s.c. Sow performance was evaluated via sow feed consumption, litter size, litter birth weights, litter weaning weights and piglet death loss from birth to weaning. Seven replicates (farrowing groups), each with six sow pairs, were included in the trial. Offspring from treated and control sows, 35 head/group, were fed to slaughter weights. Untreated sows had litters that weighed 4.14 kg less than ivermectin-treated sow litters at 21 d (P less than .07). Treated sows consumed 1.95 kg less feed per weaned piglet and .13 kg less feed per kilogram of weaned piglet (P less than .05). Piglets from treated sows were 5.79 kg/head heavier at slaughter (P less than .05) and had a .05 kg/d superior average daily gain (P less than .05).     

Molecular characterization of Babesia canis canis isolates from naturally infected dogs in Poland

Babesia canis has generally been considered the only large Babesia to infect dogs. In this study, we used PCR to detect and characterize B. canis canis isolated from naturally infected dogs in Poland by amplifying and sequencing a portion of the 18S ribosomal RNA (rRNA) gene. Venous blood samples were collected from 76 Babesia-symptomatic dogs. A 559-bp fragment of the B. canis canis 18S rRNA gene was amplified by PCR. The PCR products were then digested with HincII restriction enzyme, and isolates were classified according to whether they were cut (group A) or not (group B) by this endonuclease. Sequencing of the PCR products from the isolates led to the identification of seven sequence variants (four in group A, and three in group B). Sequences were compared with GenBank sequences, and alignments showed that all B. canis canis isolates from Europe may be classified into groups A or B as defined in our study.     

Polymorphism of glutathione S-transferase P1 of dogs with mammary tumours

Mammary tumours constitute more than half of neoplasms in female dogs from different countries. Genome sequences are associated with cancer susceptibility but there is little information available about genetic polymorphisms of glutathione S-transferase P1 (GSTP1) in canine cancers. The aim of this study was to find single nucleotide polymorphisms (SNPs) in GSTP1 of dogs (Canis lupus familiaris) with mammary tumours compared to healthy dogs and to determine the association between GSTP1 polymorphisms and the occurrence of these tumours. The study population included 36 client-owned female dogs with mammary tumours and 12 healthy female dogs, with no previous diagnosis of cancer. DNA was extracted from blood and amplified by PCR assay. PCR-products were sequenced by Sanger method and analysed manually. The 33 polymorphisms were found in GSTP1: 1 coding SNP (exon 4), 24 non-coding SNPs (9 in exon 1), 7 deletions and 1 insertion. The 17 polymorphisms have been found in introns 1, 4, 5 and 6. The dogs with mammary tumours have significant difference from healthy in SNPs I4 c.1018 + 123 T > C (OR 13.412, 95%CI 1.574–114.267, P = .001), I5 c.1487 + 27 T > C (OR 10.737, 95%CI 1.260–91.477, P = .004), I5 c.1487 + 842 G > C (OR 4.714, 95% CI 1.086–20.472, P = .046) and I6 c.2481 + 50 A > G (OR 12.000, 95% CI 1.409–102.207, P = .002). SNP E5 c.1487 T > C and I5 c.1487 + 829 delG also differed significantly (P = .03) but not to the confidence interval. The study, for the first time, showed a positive association of SNPs in GSTP1 with mammary tumours of dogs, that can possibly be used to predict the occurrence of this pathology.