Studies on schistosomiasis. 10. Development of Schistosoma mattheei in sheep infested with equal numbers of male and female cercariae

The development of the female Schistosoma mattheei was significantly higher than that of the male (P<0,0001) in 12 sheep when each was exposed to equal numbers of male and female cercariae. Many more male than female worms usually develop after infestation with pools of cercariae of mixed sexes, a phenomenon which in the light of the present results seems to be due to a preponderance of male cercariae and not to the more efficient development of male than female cercariae. The female worms recovered fell into 2 distinct population groups as regards length and pigmentation. Some overlap in the measurements of the breadths and in the numbers of ova in the uteri of the worms, however, makes the demarcation of the different populations less distinct in these respects. The female worms from 3 single-sex infestations contained either no ova (72 days after infestation) or fewer (after 134-137 days of development) than the small females from the 12 sheep. The number of large females (602) recovered from the mesentery was approximately the same as that of the males (605) from this site. Similarly, although varying numbers of small female worms were recovered from the liver of every sheep, only 2 males and 2 large females were recovered, and these were from the same liver. Because of the similarity between the numbers of male and large female worms, it is clear that, for S. mattheei, physical contact with male worms is essential for development to maturity of female worms, the mere presence of males in the host not being sufficient for this development to take place.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Cryopreservation of third-stage larvae of Strongylus vulgaris (large strongyle of horses)

A technique for the cryopreservation of third-stage larvae of Strongylus vulgaris is described. Infective larvae of S. vulgaris were exsheathed in a 0,16% sodium hypochlorite solution and then transferred into cryotubes containing 0,09% saline. The samples were stored in the gas phase of liquid nitrogen.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Cryopreservation of sheathed third-stage larvae of Oesophagostomum radiatum (nodular worm of cattle)

Sheathed infective larvae of Oesophagostomum radiatum were successfully cryopreserved by the use of a procedure developed for hookworms. The survival rate, as assessed by motility, was 57,9% after 42 d of cryopreservation.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Schistosoma mattheei infection in cattle: the course of the intestinal syndrome, and an estimate of the lethal dose of cercariae

Three groups of young oxen were infected percutaneously with cercariae of Schistosoma mattheei. Three of five oxen infected with 248 cercariae/kg mass died or were killed in extremis 58-70 d after infection, a fourth survived extremely severe clinical schistosomosis and the fifth was only slightly affected. None of seven calves infected with 187 cercariae/kg died, while one of seven exposed to 119 cercariae/kg was in extremis (possibly not from schistosomosis) when killed after 378 d. The LD₅₀ appears to be in the region of the highest dose tested (248 cercariae/kg) , but depends on variations in the viability of the cercariae used. The clinical syndrome was characterized by a drastic, rapid loss in body mass; a severe diarrhoea containing blood clots; straining, gnashing of the teeth, occasional groaning, and other signs of abdominal pain ; and markedly sunken eyes. Lethally infected oxen did not become recumbent until shortly before death. Some severely affected animals made remarkable, but slow, recoveries without treatment. Schistosomes, in close association with granulomata, are described-apparently for the first time-in the omental veins of cattle. Mean worm development in three calves that died or were killed in extremis in the acute stage of the disease, was 55,5 %. In contrast to most previous findings with S. mattheei, in two of these animals, more female than male worms developed. The worms were recovered by perfusion and, in one animal, a large number of intestinal veins were dissected open to estimate the efficiency of the perfusion method. Only 1,9% of the total worm burden had not been removed by perfusion in this animal .The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat X Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Studies on schistosomiasis. 8. The influence of age on the susceptibility of sheep to infestation with Schistosoma mattheei

Twenty-eight Dorper wethers, allocated according to age into 4 groups of 7 animals each, and 1 group of 7 Merino wethers, were compared for susceptibility to Schistosoma mattheei infestation. The group mean ages of the Dorper sheep varied from 5-61 months and their live mass from 25-66 kg, while the Merinos were 8 months old and had a mean mass of 19 kg. Despite the marked differences in the age and live mass of the Dorper sheep and the inclusion of 2 breeds in the experiment, no statistically significant differences were found in cercariae which failed to penetrate the sheep the mean percentage development of cercariae to adult worms, worm distribution in the mesenteric and gastric radicles of the portal vein and the pulmonary arterial system, and worms not removed by perfusion. Significant differences between groups (5% significance level) were found, however, in the number of worms recovered from the hepatic portal system, and in the worm sex ratio. On 3 occasions the total number of eggs excreted per female schistosome in the mesentery per 24 hours differed significantly between groups, but each time a different group or groups of sheep were responsible for the variation which was probably due, therefore, not to the age or breed of the sheep, but to daily variations in individuals. Highly significant differences occurred in the infectivity of the 6 cercarial pools used for infestation in spite of standardized collection and handling of the cercariae. Possible reasons for this are discussed and a solution suggested. Frequent egg counts (5 per sheep per week) were done during the first 25 days of patency, until the sheep were slaughtered. Schistosome ova were detected in the faeces of only 1/18 sheep examined on Day +43 after infestation, and 3/17 on Day +44, whereafter this increased rapidly to 15/34 on Day +45, 25/33 on Day +46, etc. A highly significant correlation was found between the total worm egg excretion in the faeces of the sheep per day and the numbers of female schistosomes in the mesentery, especially shortly after the onset of egg production.The articles have been scanned in colour with a HP scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to final presentyation PDF-Format

Fasciola in horses in the Republic of South Africa : a single natural case of Fasciola hepatica and the failure to infest ten horses either with F. hepatica or Fasciola gigantica

The faeces of 11 horses were examined for Fasciola spp. eggs. One of them was positive for Fasciola hepatica, a finding which was confirmed post-mortem. The 10 negative horses were subsequently infested with either F. hepatica or Fasciola gigantica, each animal receiving orally from 500-9 500 metacercariae. No clinical signs were observed and no fluke eggs were detected in the faeces, and neither immature nor adult Fasciola worms were recovered from the horses slaughtered 16-26 weeks post-infestation with F. hepatica and 28-34 weeks post-infestation with F. gigantica, respectively. The results indicate that horses have a high level of resistance to both South African Fasciola spp. Factors which can probably explain the conflicting reports for the prevalences of fascioliasis in horses throughout the world and the varying results obtained in experimental infestations are briefly considered.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.lmchunu2014mn201

Studies on schistosomiasis. 6. A field outbreak of bilharzia in cattle

An outbreak of bilharzia (Schistosoma mattheei) infestation involving about 100 oxen on the farm Otthilie near Tolwe in northern Transvaal is described. Infestation of the cattle appears to have occurred per os from a single drinking trough. The cattle showed clinical signs and pathological lesions of both the reinfestation and the acute syndromes. The worm burdens were the highest recorded hitherto in naturally infested cattle. Severe macroscopic clay pipe stem periportal fibrosis, granulomata of the ureters and severe grey pigmentation of the lungs, are described for the first time in naturally infested cattle. There was more marked liver pigmentation than had been encountered previously in this host. A striking feature in every case was conspicuous congestion and enlargement of the ileo-cecal valve, which was dark red in colour. Treatment of affected animals with injectable trichlorphon controlled the outbreak without causing mass embolism and liver infarcts. At least 11 treatments at a dosage level of 10-12 mg/kg per treatment at 3-5 day intervals are necessary. Faecal examinations for eggs or miracidia cannot be used to assess the worm burden or the clinical state of the animal. Moreover, it is suggested that this disease may be confused with other conditions and this probably accounts for the rarity of reports of outbreaks in ruminants.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Associations of common breast cancer susceptibility alleles with risk of breast cancer subtypes in BRCA1 and BRCA2 mutation carriers

Introduction: More than 70 common alleles are known to be involved in breast cancer (BC) susceptibility, and several exhibit significant heterogeneity in their associations with different BC subtypes. Although there are differences in the association patterns between BRCA1 and BRCA2 mutation carriers and the general population for several loci, no study has comprehensively evaluated the associations of all known BC susceptibility alleles with risk of BC subtypes in BRCA1 and BRCA2 carriers. Methods: We used data from 15,252 BRCA1 and 8,211 BRCA2 carriers to analyze the associations between approximately 200,000 genetic variants on the iCOGS array and risk of BC subtypes defined by estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and triple-negative- (TN) status; morphologic subtypes; histological grade; and nodal involvement. Results: The estimated BC hazard ratios (HRs) for the 74 known BC alleles in BRCA1 carriers exhibited moderate correlations with the corresponding odds ratios from the general population. However, their associations with ER-positive BC in BRCA1 carriers were more consistent with the ER-positive as

Functional mechanisms underlying pleiotropic risk alleles at the 19p13.1 breast-ovarian cancer susceptibility locus

A locus at 19p13 is associated with breast cancer (BC) and ovarian cancer (OC) risk. Here we analyse 438 SNPs in this region in 46,451 BC and 15,438 OC cases, 15,252 BRCA1 mutation carriers and 73,444 controls and identify 13 candidate causal SNPs associated with serous OC (P=9.2 × 10-20), ER-negative BC (P=1.1 × 10-13), BRCA1-associated BC (P=7.7 × 10-16) and triple negative BC (P-diff=2 × 10-5). Genotype-gene expression associations are identified for candidate target genes ANKLE1 (P=2 × 10-3) and ABHD8 (P<2 × 10-3). Chromosome conformation capture identifies interactions between four candidate SNPs and ABHD8, and luciferase assays indicate six risk alleles increased transactivation of the ADHD8 promoter. Targeted deletion of a region containing risk SNP rs56069439 in a putative enhancer induces ANKLE1 downregulation; and mRNA stability assays indicate functional effects for an ANKLE1 3′-UTR SNP. Altogether, these data suggest that multiple SNPs at 19p13 regulate ABHD8 and perhaps ANKLE1 expression, and indicate common mechanisms underlying breast and ovarian cancer risk

Genome-Wide Association Study in BRCA1 Mutation Carriers Identifies Novel Loci Associated with Breast and Ovarian Cancer Risk

BRCA1-associated breast and ovarian cancer risks can be modified by common genetic variants. To identify further cancer risk-modifying loci, we performed a multi-stage GWAS of 11,705 BRCA1 carriers (of whom 5,920 were diagnosed with breast and 1,839 were diagnosed with ovarian cancer), with a further replication in an additional sample of 2,646 BRCA1 carriers. We identified a novel breast cancer risk modifier locus at 1q32 for BRCA1 carriers (rs2290854, P = 2.7×10-8, HR = 1.14, 95% CI: 1.09-1.20). In addition, we identified two novel ovarian cancer risk modifier loci: 17q21.31 (rs17631303, P = 1.4×10-8, HR = 1.27, 95% CI: 1.17-1.38) and 4q32.3 (rs4691139, P = 3.4×10-8, HR = 1.20, 95% CI: 1.17-1.38). The 4q32.3 locus was not associated with ovarian cancer risk in the general population or BRCA2 carriers, suggesting a BRCA1-specific associat