The bovine foot skin microbiota is associated with host genotype and the development of infectious digital dermatitis lesions.

BACKGROUND: Bovine Digital Dermatitis (BDD) is a prevalent infectious disease, causing painful foot skin lesions and lameness in cattle. We describe herein the bovine foot skin microbiota and its associations with BDD using 16S rRNA gene amplicon and shotgun metagenomic sequencing on samples from 259 dairy cows from three UK dairy farms. RESULTS: We show evidence of dysbiosis, and differences in taxonomy and functional profiles in the bovine foot skin microbiome of clinically healthy animals that subsequently develop BDD lesions, compared to those that do not. Our results suggest that taxonomical and functional differences together with alterations in ecological interactions between bacteria in the normal foot skin microbiome may predispose an animal to develop BDD lesions. Using genome-wide association and regional heritability mapping approaches, we provide first evidence for interactions between host genotype and certain members of the foot skin microbiota. We show the existence of significant genetic variation in the relative abundance of Treponema spp. and Peptoclostridium spp. and identify regions in the bovine genome that explain a significant proportion of this variation. CONCLUSIONS: Collectively this work shows early changes in taxonomic and functional profiles of the bovine foot-skin microbiota in clinically healthy animals which are associated with subsequent development of BDD and could be relevant to prevention of disease. The description of host genetic control of members of the foot skin microbiota, combined with the association of the latter with BDD development offer new insights into a complex relationship that can be exploited in selective breeding programmes. Video Abstract.

16S rRNA amplicon sequencing reveals a polymicrobial nature of complicated claw horn disruption lesions and interdigital phlegmon in dairy cattle.

Lameness represents an intractable problem for the dairy industry. Complicated claw horn disruption lesions, interdigital hyperplasia, and interdigital phlegmon are important lameness causing foot lesions. Their aetiology is multifactorial, but infectious processes are likely implicated in disease pathogenesis. Our aim was to investigate the bacterial profiles of these lesions using 16S rRNA gene sequencing of samples obtained from 51 cattle across ten farms in the UK. In this study, interdigital hyperplasia, interdigital hyperplasia with signs of interdigital dermatitis, interdigital phlegmon, complicated sole ulcers, complicated toe ulcers lesions, and complicated white line lesions were investigated; corresponding healthy skin control samples were also analysed. All diseased tissues displayed reduced microbial richness and diversity (as described by Chao1, Shannon, and Simpson alpha-diversity indices) compared to their healthy skin control samples. Our results confirm the association of Treponema spp with some of these disorders. Other anaerobic bacteria including Fusobacterium spp., Fastidiosipila spp. and Porphyromonas spp. were implicated in the aetiology of all these lesions with the exception of interdigital hyperplasia. Complicated claw horn disruption lesions, and interdigital phlegmon were found to have similar bacterial profiles. Such sharing of bacterial genera suggests many of the infectious agents detected in these foot lesions are acting opportunistically; this finding could contribute towards future treatment and control strategies.

Surface-confined [2 + 2] cycloaddition towards one-dimensional polymers featuring cyclobutadiene units.

Surface-confined synthesis has been offering a wide range of opportunities for the construction of novel molecular nanostructures. Exploring new types of on-surface coupling reactions is considered essential for being able to deliberately tune the materials properties. Here, we report on the formation of a covalent C-C bonding motif, namely 1,3-cyclobutadiene, via surface-confined [2 + 2] cycloaddition between pyrene moieties using low temperature scanning tunneling microscopy (LT-STM) and X-ray photoemission spectroscopy (XPS) measurements. By employing a hydrogen dosing treatment together with low-temperature activation, we were able to both eliminate residual byproducts and obtain covalent 1D polymers through the formation of 1,3-cyclobutadiene units. The resulting C-C bonding motif has so far hardly been explored in surface chemistry and substantial evidence is provided that the hydrogen treatment is crucial towards the removal of byproducts in surface-confined polymerization.

On-Surface Formation of Cumulene by Dehalogenative Homocoupling of Alkenyl gem-Dibromides.

The on-surface activation of carbon-halogen groups is an efficient route to produce radicals for constructing various hydrocarbons and carbon nanostructures. To date, the employed halide precursors have only one halogen attached to a carbon atom. It is thus of interest to study the effect of attaching more than one halogen atom to a carbon atom with the aim of producing multiple unpaired electrons. By introducing an alkenyl gem-dibromide, cumulene products were fabricated on a Au(111) surface by dehalogenative homocoupling reactions. The reaction products and pathways were unambiguously characterized by a combination of high-resolution scanning tunneling microscopy and non-contact atomic force microscopy measurements together with density functional calculations. This study further supplements the database of on-surface synthesis strategies and provides a facile manner for incorporation of more complicated carbon scaffolds into surface nanostructures.

Chiral-Selective Formation of 1D Polymers Based on Ullmann-Type Coupling: The Role of the Metallic Substrate.

The chiral-selective formation of 1D polymers from a prochiral molecule, namely, 6,12-dibromochrysene in dependence of the type of metal surface is demonstrated by a combined scanning tunneling microscopy and density functional theory study. Deposition of the chosen molecule on Au(111) held at room temperature leads to the formation of a 2D porous molecular network. Upon annealing at 200 °C, an achiral covalently linked polymer is formed on Au(111). On the other hand, a chiral Cu-coordinated polymer is spontaneously formed upon deposition of the molecules on Cu(111) held at room temperature. Importantly, it is found that the chiral-selectivity determines the possibility of obtaining graphene nanoribbons (GNRs). On Au(111), upon annealing at 350 °C or higher cyclo-dehydrogenation occurs transforming the achiral polymer into a GNR. In contrast, the chiral coordination polymer on Cu(111) cannot be converted into a GNR.

[Struma with euthyroidism ]. / Struma mit Euthyreose.

A total of 75-85% of thyroid operations are performed on euthyroid goiters; 70% of them are bilateral. Ultrasonography is the most important preoperatively examination. But even lobes classified as normal should be inspected carefully during operations: nodules were found in so called "normal" lobes in 22%. All nodules have to be resected, and attention must be paid to retrosternal and retrovisceral parts. Identification of recurrent nerves and parathyroid glands is necessary. Recurrent goiters should be prepared intercapsularly. In our own 3049 cases of euthyroid goiters 2.4% had early recurrent nerve paralysis, 3.9% retrosternal and 6.6% recurrent goiters.

Diffuse sclerosing variant of papillary thyroid carcinoma. S-100 protein immunocytochemistry and prognosis.

The recently published second edition of the WHO classification of thyroid tumours describes the diffuse sclerosing papillary carcinoma (DSPC) as a specific variant of papillary thyroid cancer (PC). Besides several histological hallmarks, this rare tumour is characterized by its occurrence in young individuals and is thought to have a less favourable prognosis than PC in general. The observations on two examples of this tumour presented herein, however, are at variance at this assumption. The neoplasms occurred in a 10 year old girl and a 34 year old woman. Each time, diffuse involvement of both thyroid lobes and bilateral cervical lymphadenopathy were seen. In one case, the carcinoma extended into the cervical soft tissue. Follow-up disclosed both patients to be without evidence of disease 2 and 13 years, respectively, after thyroid surgery. Immunocytochemically, both thyroid primaries as well as 7 other cases of DSPC reported in the literature showed dense accumulations of S-100 protein positive dendritic/Langerhans cells. Such infiltrations have been demonstrated to be correlated with a benign clinical course of PC. It is thus suggested that DSPC behaves similarly or even less aggressively than PC in general, at least if prominent Langerhans cell infiltration is present.

[Immunohistology and prognosis in thyroid cancer. Determination of the malignancy potential of papillary and medullary neoplasms by the detection of S-100 protein and Leu-M1 antigen]. / Immunhistologie und Prognose beim Schilddrüsenkarzinom. Bestimmung des Malignitätspotentials papillärer und medullärer Neoplasien durch S-100-Protein- und Leu-M1-Antigen-Nachweis.

170 thyroid carcinomas were investigated for the presence of S-100-protein-positive Langerhans cells (LC) and the expression of Leu-M1-antigen. Dense LC infiltrates were found only in papillary tumours and were shown to be significantly related to prognosis. Irrespective of any other feature, no single instance of death resulting from cancer occurred among 23 tumours (including 6 cases of stage pT4) with dense infiltrates (greater than 20 LC/unit field) while 9/53 (17%) of the remaining patients died from carcinoma (p less than 0.01). The degree of epithelial Leu-M1 expression was significantly related to the biological behaviour of papillary and medullary neoplasms. Death resulting from cancer occurred 17 times more frequently among papillary tumours with marked positivity (greater than 15%) as compared to cases with slight or absent immunoreactivity (8/24 vs. 1/52; p less than 0.00005). Among medullary carcinomas, local recurrences occurred 2.9 times (14/16 vs. 7/23; p less than 0.005) and death resulting from tumour occurred 4.3 times (9/16 vs. 3/23; p less than 0.03) more frequently for intensely stained as compared to slightly immunoreactive and unstained neoplasms.

[Perforation of gastroduodenal ulcer. Risk factors and choice of procedure]. / Perforation des gastroduodenalen Ulkus. Risikofaktoren und Verfahrenswahl.

The well known surgical risk factors, such as age, time of perforation as well as size and localisation of necrosis, were confirmed in retrospective and prospective analyses of perforation of gastroduodenal ulcers (n = 504). Incidence was unchanged in the two different time-related groups, with 3.2 or 3.7 cases in one month. There was a clear-cut need for excision of the ulcer or necrotic margin. Perforation was attributable to malignant tumours in 2.1 per cent of the cases. The authors have definitely adopted the concept of earlier primary surgery (23 per cent of all cases, as compared to 10.4 per cent before). The risk associated to it was found to be lower than linked to palliative operations. The lethality rate was as low as 7.6 per cent, once due consideration was given to the above risk factors for adequate choice of surgical methods. Particular attention was given to ulcer localisation and clinical course. Hence, lethality has clearly dropped below earlier data.