Isolation and characterization of an atypical Mycoplasma gallisepticum strain showing a new mgc2 variant

Mycoplasma gallisepticum (MG) is an important pathogen of the poultry industry able to cause chronic respiratory disease in chickens and infectious sinusitis in turkeys. Despite the application of biosecurity measures and the availability of vaccines for chickens, monitoring systems routinely applied for MG detection are still essential for infection control. Pathogen isolation is time-consuming and not suitable for rapid detection, albeit it is a compulsory step for genetic typing and antimicrobial susceptibility evaluation of single strains. The mgc2 gene is a species-specific molecular target adopted by most of the PCR protocols available for MG diagnosis, which are also included in the WOAH Terrestrial Manual. We describe the case of an atypical MG strain, isolated in 2019 from Italian turkeys, characterized by an mgc2 sequence not detectable by common endpoint PCR primers. Considering the potential risk of false negative results during diagnostic screenings with the endpoint protocol, the authors propose an alternative mgc2 PCR endpoint protocol, named MG600, which should be considered as a further diagnostic tool.

Structural insights into DNMT5-mediated ATP-dependent high-fidelity epigenome maintenance

Epigenetic evolution occurs over million-year timescales in Cryptococcus neoformans and is mediated by DNMT5, the first maintenance type cytosine methyltransferase identified in the fungal or protist kingdoms, the first dependent on adenosine triphosphate (ATP), and the most hemimethyl-DNA-specific enzyme known. To understand these novel properties, we solved cryo-EM structures of CnDNMT5 in three states. These studies reveal an elaborate allosteric cascade in which hemimethylated DNA binding first activates the SNF2 ATPase domain by a large rigid body rotation while the target cytosine partially flips out of the DNA duplex. ATP binding then triggers striking structural reconfigurations of the methyltransferase catalytic pocket to enable cofactor binding, completion of base flipping, and catalysis. Bound unmethylated DNA does not open the catalytic pocket and is instead ejected upon ATP binding, driving high fidelity. This unprecedented chaperone-like, enzyme-remodeling role of the SNF2 ATPase domain illuminates how energy is used to enable faithful epigenetic memory.

172 The Perceived Effect of COVID-19 on Surgical Training in Malta and the UK

Introduction

Surgical training comprises of learning in a number of environments – practical experience in hospital, educational activities, reaching core competencies and academic development. The COVID-19 pandemic has had significant effects on healthcare systems, and this likely will have impacted surgical training. This survey set out to assess the perceived effects of COVID-19 on surgical training.

Method

A survey was circulated amongst surgical trainees to assess perceived effects from the COVID-19 pandemic on their surgical training. This was circulated amongst surgical trainees in Malta and London. 32 surgical trainees from Malta and 25 from London responded. Results were analysed, tabulated and compared.

Results

Less Malta trainees were redeployed than UK (3% vs 80%), whist both had rotations postponed or cancelled (62.5% vs. 92%). Trainees felt logbook opportunities (78% vs 100%) and theatre experience (97% vs 100%) had reduced. Trainees were unsure of how this would affect their progression (56% vs 52%), and some felt recruitment criteria should be adjusted in view of the above (50% vs 68%). Overall, both groups agreed their surgical education had been negatively impacted (84% vs 100%).

Conclusions

Both UK and Malta trainees feel that surgical training has been negatively impacted during the COVID-19 pandemic.

171 Surgical Trainee Suggestions to Improve Surgical Training and the Surgical Recruitment Process in View of the COVID-19 Pandemic

Introduction

The COVID-19 pandemic has had a significant impact on medical education and surgical training. The experiences of surgical trainees were sought to seek feedback on how both training and recruitment can be adapted to reflect these changes.

Method

A survey was circulated amongst surgical trainees, to ask what changes to the recruitment process and surgical training they would suggest, in view of the changes related to the COVID-19 pandemic. Circulated amongst surgical trainees in London. 25 surgical trainees from London responded. Results were analysed and tabulated.

Results

Suggestions for the recruitment process include an appreciation by the recruitment panel about reduced academic achievement, relaxation of requirements, clinically oriented interviews and extension of training. Suggestions for surgical training include resumption of educational activities, ensured surgical activities and protected theatre time, mentorship and run through training.

Conclusions

The effects on surgical training due to COVID-19 must be appreciated, and trainees’ experience and feedback should be considered when adapting training and recruitment to this.

ATP Hydrolysis by the SNF2 Domain of Dnmt5 Is Coupled to Both Specific Recognition and Modification of Hemimethylated DNA

C.neoformans Dnmt5 is an unusually specific maintenance-type CpG methyltransferase (DNMT) that mediates long-term epigenome evolution. It harbors a DNMT domain and SNF2 ATPase domain. We find that the SNF2 domain couples substrate specificity to an ATPase step essential for DNA methylation. Coupling occurs independent of nucleosomes. Hemimethylated DNA preferentially stimulates ATPase activity, and mutating Dnmt5's ATP-binding pocket disproportionately reduces ATPase stimulation by hemimethylated versus unmethylated substrates. Engineered DNA substrates that stabilize a reaction intermediate by mimicking a "flipped-out" conformation of the target cytosine bypass the SNF2 domain's requirement for hemimethylation. This result implies that ATP hydrolysis by the SNF2 domain is coupled to the DNMT domain conformational changes induced by preferred substrates. These findings establish a new role for a SNF2 ATPase: controlling an adjoined enzymatic domain's substrate recognition and catalysis. We speculate that this coupling contributes to the exquisite specificity of Dnmt5 via mechanisms related to kinetic proofreading.

Evolutionary Persistence of DNA Methylation for Millions of Years after Ancient Loss of a De Novo Methyltransferase

Cytosine methylation of DNA is a widespread modification of DNA that plays numerous critical roles. In the yeast Cryptococcus neoformans, CG methylation occurs in transposon-rich repeats and requires the DNA methyltransferase Dnmt5. We show that Dnmt5 displays exquisite maintenance-type specificity in vitro and in vivo and utilizes similar in vivo cofactors as the metazoan maintenance methylase Dnmt1. Remarkably, phylogenetic and functional analysis revealed that the ancestral species lost the gene for a de novo methylase, DnmtX, between 50-150 mya. We examined how methylation has persisted since the ancient loss of DnmtX. Experimental and comparative studies reveal efficient replication of methylation patterns in C. neoformans, rare stochastic methylation loss and gain events, and the action of natural selection. We propose that an epigenome has been propagated for >50 million years through a process analogous to Darwinian evolution of the genome.

Centromere DNA Destabilizes H3 Nucleosomes to Promote CENP-A Deposition during the Cell Cycle

Active centromeres are defined by the presence of nucleosomes containing CENP-A, a histone H3 variant, which alone is sufficient to direct kinetochore assembly. Once assembled at a location, CENP-A chromatin and kinetochores are maintained at that location through a positive feedback loop where kinetochore proteins recruited by CENP-A promote deposition of new CENP-A following replication. Although CENP-A chromatin itself is a heritable entity, it is normally associated with specific sequences. Intrinsic properties of centromeric DNA may favor the assembly of CENP-A rather than H3 nucleosomes. Here we investigate histone dynamics on centromere DNA. We show that during S phase, histone H3 is deposited as a placeholder at fission yeast centromeres and is subsequently evicted in G2, when we detect deposition of the majority of new CENP-A^Cnp1. We also find that centromere DNA has an innate property of driving high rates of turnover of H3-containing nucleosomes, resulting in low nucleosome occupancy. When placed at an ectopic chromosomal location in the absence of any CENP-A^Cnp1 assembly, centromere DNA appears to retain its ability to impose S phase deposition and G2 eviction of H3, suggesting that features within centromere DNA program H3 dynamics. Because RNA polymerase II (RNAPII) occupancy on this centromere DNA coincides with H3 eviction in G2, we propose a model in which RNAPII-coupled chromatin remodeling promotes replacement of H3 with CENP-A^Cnp1 nucleosomes.

Application of different laboratory techniques to monitor the behaviour of a Mycoplasma synoviae vaccine (MS-H) in broiler breeders

Background

Mycoplasma synoviae (MS) is a major poultry pathogen which causes severe economic losses in all the productive sectors. The prevalence of MS in European countries has increased in the last few years, leading to greater attention to the available methods to prevent its spread. The main strategy currently applied for its containment is the development and maintenance of MS-free breeder flocks. A live MS vaccine (MS-H) obtained by mutagenizing an Australian field strain has recently been introduced in Italy. The aim of the present study was to evaluate the vaccine behaviour in broiler breeder groups at different production stages and the effectiveness of the available laboratory tests in discriminating the MS-H from a field strain.

Results

The vaccine diffused extensively through the population, shown by the wide serological response (over 80% of positive samples in RSA and 85% in ELISA), the high serological titres, the positivity of all the tracheal samples collected during the production phase by MS PCR and the positivity by cultivation from tracheal swabs at the end-point (55 weeks after vaccination). In contrast, only one swab from a sternal bursa was positive in MS PCR, while all the joint and oviduct samples were negative. There was no evidence of vertical transmission. Different genotyping techniques were used to achieve a clear classification of the MS positive samples. The vlhA and the obg gene analysis showed that most of the strains were homologous with the vaccine, but some ambiguous samples were further investigated with the multi locus sequence typing (MLST) scheme which confirmed the homology.

Conclusions

The development of a multi-technique approach to monitor vaccinated avian flocks, based both on serological and biomolecular methods, is advised as well as the use of effective genotyping techniques to analyse the MS strains circulating in high densely populated poultry areas.

Electronic supplementary material

The online version of this article (10.1186/s12917-018-1669-8) contains supplementary material, which is available to authorized users.

Detection of the 170 kDa P-Glycoprotein in Neoplastic and Normal Tissues

A membrane purification procedure and an immunoblotting assay have been designed to allow screening of human solid tumors for overexpression of the GP170 glycoprotein without employing a disaggregation method to obtain cell suspensions. The electrophoresed membrane proteins were probed, after Western Blotting, with the C219 monoclonal antibody and iodinated Protein A. The labeling intensity of the bands on the autoradioimmunoblots were quantified by densitometry. To test for the presence of GP170, we used membranes from the UV 2237 fibrosarcoma line and its adriamycin-resistant variant ADMR, grown in vitro or as solid tumor in mice. Membranes of human normal and tumor tissues obtained from previously untreated patients were also tested. An immunoreaction was observed in the adriamycin-resistant UV 2237 lines grown in vitro or in vivo. Quantitatively, the binding of the resistant cell line grown in vitro was higher than that observed in cells grown in mice. Bands in the GP 170 region were observed in 4/7 normal and in 7/7 tumor colon tissues and in the normal medulla from 2 patients with cancer of the renal cortex. No reaction could be found in samples from normal tissue, primary tumor or nodal metastasis from 7 patients with breast cancer.

Favorable effects of myo-inositol, selenomethionine or their combination on the hydrogen peroxide-induced oxidative stress of peripheral mononuclear cells from patients with Hashimoto's thyroiditis: preliminary in vitro studies

OBJECTIVE

The aim of this study was to assess whether blood mononuclear cells (PBMC) from Hashimoto's thyroiditis (HT) and control women, were protected from in vitro H2O2-induced oxidative stress after addition of antioxidants.

PATIENTS AND METHODS

PBMC, from 8 HT women and 3 healthy women (controls), were cultured in the presence of 200 µM H2O2 alone, with subsequent addition of myo-inositol (Myo) (0.25, 0.5, 1.0 µM), selenomethionine (SelMet) (0.25, 0.5, 1.0 µM), or their combination (0.25+0.25, 0.5+0.5, 1.0+1.0 µM). PBMC proliferation, vitality, genotoxicity (Comet score) and secretion in the medium of the chemokines CXCL10 [IP10], CCL2 e CXCL9 [MIG] were the indices measured.

RESULTS

PBMC proliferation was decreased by H2O2 alone, and it decreased further and dose-dependently in either group (greatest decrease with Myo+SelMet in HT). H2O2 alone decreased vitality by 5% in controls and 10% in the HT group, but vitality was rescued by the three additions. The addition of H2O2 alone increased the Comet score at +505% above baseline in controls and +707% in HT women. In either group, each addition dose-dependently contrasted genotoxicity. Concentrations of chemokines in the medium were increased by H2O2 alone, and in HT women more than in controls. Each addition dose-dependently decreased these concentrations in either group, and often below baseline levels, with Myo+SelMet being the most potent addition (up to approximately -80% of baseline).

CONCLUSIONS

The tested antioxidants exert beneficial effects on PBMC exposed in vitro to H2O2-induced oxidative stress in both control and HT women. Particularly, the association Myo+SelMet is the most effective. After the demonstration of a favorable in vitro outcomes in a large cohort of HT patients, we could predict favorable in vivo outcomes given by the same supplement. Thus, one can select HT patients with a high chance of benefit from supplementation.

Evaluation of the udder health status in subclinical mastitis affected dairy cows through bacteriological culture, somatic cell count and thermographic imaging

Subclinical mastitis in dairy cows is a big economic loss for farmers. The monitoring of subclinical mastitis is usually performed through Somatic Cell Count (SCC) in farm but there is the need of new diagnostic systems able to quickly identify cows affected by subclinical infections of the udder. The aim of this study was to evaluate the potential application of thermographic imaging compared to SCC and bacteriological culture for infection detection in cow affected by subclinical mastitis and possibly to discriminate between different pathogens. In this study we evaluated the udder health status of 98 Holstein Friesian dairy cows with high SCC in 4 farms. From each cow a sample of milk was collected from all the functional quarters and submitted to bacteriological culture, SCC and Mycoplasma spp. culture. A thermographic image was taken from each functional udder quarter and nipple. Pearson's correlations and Analysis of Variance were performed in order to evaluate the different diagnostic techniques. The most frequent pathogen isolated was Staphylococcus aureus followed by Coagulase Negative Staphylococci (CNS), Streptococcus uberis, Streptococcus agalactiae and others. The Somatic Cell Score (SCS) was able to discriminate (p<0.05) cows positive for a pathogen from cows negative at the bacteriological culture except for cows with infection caused by CNS. Infrared thermography was correlated to SCS (p<0.05) but was not able to discriminate between positive and negative cows. Thermographic imaging seems to be promising in evaluating the inflammation status of cows affected by subclinical mastitis but seems to have a poor diagnostic value.

Epigenetics. Restricted epigenetic inheritance of H3K9 methylation

Posttranslational histone modifications are believed to allow the epigenetic transmission of distinct chromatin states, independently of associated DNA sequences. Histone H3 lysine 9 (H3K9) methylation is essential for heterochromatin formation; however, a demonstration of its epigenetic heritability is lacking. Fission yeast has a single H3K9 methyltransferase, Clr4, that directs all H3K9 methylation and heterochromatin. Using releasable tethered Clr4 reveals that an active process rapidly erases H3K9 methylation from tethering sites in wild-type cells. However, inactivation of the putative histone demethylase Epe1 allows H3K9 methylation and silent chromatin maintenance at the tethering site through many mitotic divisions, and transgenerationally through meiosis, after release of tethered Clr4. Thus, H3K9 methylation is a heritable epigenetic mark whose transmission is usually countered by its active removal, which prevents the unauthorized inheritance of heterochromatin.

Treatment of relapsed Wilms tumour (WT) patients: experience with topotecan. A report from the SIOP Renal Tumour Study Group (RTSG)

BACKGROUND

Topotecan has been variably incorporated in the treatment of patients with relapsed Wilms tumour (WT) who failed initial treatment with three or more effective drugs. Our objective was to describe outcome and to retrospectively investigate the potential role of topotecan in relapsed WT patients.

METHODS

Children who were treated with topotecan as part of their chemotherapeutic regimens for relapsed WT were identified and included in our retrospective study. Patient charts were reviewed for general patient characteristics, histology and stage at initial diagnosis, number and type of relapse, salvage treatment schedules, toxicity, response to treatment and outcome.

RESULTS

From 2000 to 2012, 30 children (median age at relapse 5.5 years, range 1.6-14.5 years) were identified to have received topotecan as part of their salvage regimens (primary progressive disease n = 3, first, second and third relapse n = 13, 9 and 2 respectively, partial response n = 3). Topotecan was administered as a single agent (12 patients) or in combination with other drugs (18 patients). Sixteen patients had high-risk histology according to the SIOP classification, 15 died within 12 months because of progressive disease. Fourteen patients had SIOP intermediate-risk histology of which four patients displayed objective responses to topotecan. Overall, 6 out of 14 intermediate-risk patients survived (median follow up of 6 years), however, three of whom (stage V) had bilateral nephrectomy after topotecan treatment.

CONCLUSIONS

Topotecan does not seem to show effectiveness in the treatment of relapsed WT patients with initial high-risk histology. In patients with intermediate-risk histology, the role of topotecan might deserve further attention, to prove its efficacy.

Sequence features and transcriptional stalling within centromere DNA promote establishment of CENP-A chromatin

Centromere sequences are not conserved between species, and there is compelling evidence for epigenetic regulation of centromere identity, with location being dictated by the presence of chromatin containing the histone H3 variant CENP-A. Paradoxically, in most organisms CENP-A chromatin generally occurs on particular sequences. To investigate the contribution of primary DNA sequence to establishment of CENP-A chromatin in vivo, we utilised the fission yeast Schizosaccharomyces pombe. CENP-ACnp1 chromatin is normally assembled on ∼10 kb of central domain DNA within these regional centromeres. We demonstrate that overproduction of S. pombe CENP-ACnp1 bypasses the usual requirement for adjacent heterochromatin in establishing CENP-ACnp1 chromatin, and show that central domain DNA is a preferred substrate for de novo establishment of CENP-ACnp1 chromatin. When multimerised, a 2 kb sub-region can establish CENP-ACnp1 chromatin and form functional centromeres. Randomization of the 2 kb sequence to generate a sequence that maintains AT content and predicted nucleosome positioning is unable to establish CENP-ACnp1 chromatin. These analyses indicate that central domain DNA from fission yeast centromeres contains specific information that promotes CENP-ACnp1 incorporation into chromatin. Numerous transcriptional start sites were detected on the forward and reverse strands within the functional 2 kb sub-region and active promoters were identified. RNAPII is enriched on central domain DNA in wild-type cells, but only low levels of transcripts are detected, consistent with RNAPII stalling during transcription of centromeric DNA. Cells lacking factors involved in restarting transcription-TFIIS and Ubp3-assemble CENP-ACnp1 on central domain DNA when CENP-ACnp1 is at wild-type levels, suggesting that persistent stalling of RNAPII on centromere DNA triggers chromatin remodelling events that deposit CENP-ACnp1. Thus, sequence-encoded features of centromeric DNA create an environment of pervasive low quality RNAPII transcription that is an important determinant of CENP-ACnp1 assembly. These observations emphasise roles for both genetic and epigenetic processes in centromere establishment.

Cloning, expression, and antigenic characterization of recombinant protein of Mycoplasma gallisepticum expressed in Escherichia coli

Mycoplasma gallisepticum (MG) is a member of the most important avian mycoplasmas, causing chronic respiratory disease in chickens and leading to important economic losses in the poultry industry. Recombinant technology represents a strategic approach used to achieve highly reliable and specific diagnostic tests in veterinary diseases control: in particular this aspect is crucial for confirming mycoplasma infection and for maintaining mycoplasma-free breeder flocks. In this study, we identified a component of the pyruvate dehydrogenase dihydrolipoamide acetyltransferase (i.e., E2) protein by 2-dimensional electrophoresis (2-DE), characterized it in immunoblotting assays, and analyzed its recombinant (r-E2) in a rec-ELISA test. For full-length protein expression in Escherichia coli (EC) a point mutation was introduced. A rabbit antiserum produced against r-E2 was tested in a Western Blot using different samples of Mycoplasma species. The results showed the applicability of site-directed mutagenesis, with a good yield of the r-E2 after purification. Also, anti-E2 serum reacted with all the tested MG strains showing no cross reaction with other mycoplasmas. The developed E2 ELISA test was capable of detecting MG antibodies in the sera examined. Those results demonstrate the antigenic stability of the E2 protein which could represent a recombinant antigen with potential diagnostic applications.

[Differences in sports participation for children and adolescents with solitary kidney due to renal tumors across Europe. Time for harmonization]

As a result of advances in treatment, almost 90% of children diagnosed with Wilms tumor became long-term survivors, and have a sustainable quality of life. These patients' involvement in sports during their childhood is hopefully increasing too. The cornerstone of renal tumor cure remains radical nephrectomy, however, so survivors live with a solitary kidney. In most European countries and the USA, the involvement in sports of children with a solitary kidney depends on a responsible physician saying a "qualified yes", pending individual assessment. Unlike the case in the rest of Europe, in Italy having only one kidney automatically disqualifies an individual wishing to participate in any organized "competitive" sports carrying some risk of renal trauma, including basketball, soccer and sometime volleyball. This absolute restriction is based on ad hoc Ministerial rulings concerning "Health protection in sport activities". But available data do not seem to support such an absolute limitation on participation in sports based exclusively on the fact of having a single kidney. The sport-specific incidence of kidney injuries has been estimated at 2.3 injuries per million male athlete/exposures for basketball (2.5 for females), and 2.6 for soccer (6.0 for girls). Kidney injuries are significantly more rare than head or spine injuries. This article aims to provide Italian sport medicine specialists and policy-makers with the necessary background so that the current, over-protective "unquestionably no" response can be reconsidered, and converted into a still well-founded, more permissive attitude to the sports activities suitable for any children with a solitary normal kidney.

Anarchic centromeres: deciphering order from apparent chaos

Specialised chromatin in which canonical histone H3 is replaced by CENP-A, an H3 related protein, is a signature of active centromeres and provides the foundation for kinetochore assembly. The location of centromeres is not fixed since centromeres can be inactivated and new centromeres can arise at novel locations independently of specific DNA sequence elements. Therefore, the establishment and maintenance of CENP-A chromatin and kinetochores provide an exquisite example of genuine epigenetic regulation. The composition of CENP-A nucleosomes is contentious but several studies suggest that, like regular H3 particles, they are octamers. Recent analyses have provided insight into how CENP-A is recognised and propagated, identified roles for post-translational modifications and dissected how CENP-A recruits other centromere proteins to mediate kinetochore assembly.

Etanercept induces improvement of arthropathy in chronic infantile neurological cutaneous articular (CINCA) syndrome

Chronic infantile neurological cutaneous articular (CINCA) syndrome is a rare disorder of unknown aetiology with neonatal onset, characterized by severe arthropathy, persistent skin rash and central nervous system disease. Joint involvement may vary from minimal swelling to destructive arthritis, with inability to stand or walk. The most striking findings of CINCA syndrome are cartilage anomalies with epiphyseal modifications and abnormal ossification, for which a pathogenetic role of tumour necrosis factor-alpha (TNF-alpha) is postulated. We describe a 4-year-old child affected with CINCA syndrome and presenting progressive joint disease, in whom non-steroidal anti-inflammatory drugs (NSAID) and systemic corticosteroidal therapy had been ineffective. Etanercept, anti-TNF-alpha therapy, was administered over a 6-month-period resulting in a dramatic improvement of the arthropathy. This good response to anti-cytokine treatment supports our hypothesis that TNF-alpha might play an important role in the pathogenesis of CINCA syndrome, which needs to be evaluated and confirmed in further studies.

Cystatin B and its EPM1 mutants are polymeric and aggregate prone in vivo

Progressive myoclonus epilepsy type 1 (EPM1) is a neurodegenerative disease correlating with mutations of the cystatin B gene. Cystatin B is described as a monomeric protein with antiprotease function. This work shows that, in vivo, cystatin B has a polymeric structure, highly resistant to SDS, urea, boiling and sensitive to reducing agents and alkaline pH. Hydrogen peroxide increases the polymeric structure of the protein. Mass spectrometry analysis shows that the only component of the polymers is cystatin B. EPM1 mutants of cystatin B transfected in cultured cells are also polymeric. The banding pattern generated by a cysteine-minus mutant is different from that of the wild-type protein as it contains only monomers, dimers and some very high MW bands while misses components of MW intermediate between 25 and 250 kDa. Overexpression of wild-type or EPM1 mutants of cystatin B in neuroblastoma cells generates cytoplasmic aggregates. The cysteine-minus mutant is less prone to the formation of inclusion bodies. We conclude that cystatin B in vivo has a polymeric structure sensitive to the redox environment and that overexpression of the protein generates aggregates. This work describes a protein with a physiological role characterized by highly stable polymers prone to aggregate formation in vivo.

Neurotrophin and Trk neurotrophin receptors in the inner ear of Salmo salar and Salmo trutta

Neurotrophins (NTs) and their signal transducing Trk receptors play a critical role in the development and maintenance of specific neuronal populations in the nervous system of higher vertebrates. They are responsible for the innervation of the inner ear cochlear and vestibular sensory epithelia. Neurotrophins and Trks are also present in teleosts but their distribution in the inner ear is unknown. Thus, in the present study, we used Western-blot analysis and immunohistochemistry to investigate the expression and cell localization of both NTs and Trk receptors in the inner ear of alevins of Salmo salar and Salmo trutta. Western-blot analysis revealed the occurrence of brain-derived neurotrophic factor (BDNF) and neurotrophin-3 (NT-3), but not nerve growth factor (NGF), as well as all three Trk receptors, i.e. TrkA, TrkB and TrkC, the estimated molecular weights of which were similar to those expected for mammals. Specific immunoreactivity for neurotrophins was detected mainly in the sensory epithelia. In particular, BDNF immunoreactivity was found in the maculae of the utricle and saccule, whereas NT-3 immunoreactivity was present in the sensory epithelium of the cristae ampullaris. As a rule the sensory epithelia of the inner ear lacked immunoreactivity for Trks, thus excluding possible mechanisms of autocrinia and/or paracrinia. By contrast, overlapping subpopulations of neurons in the statoacoustic ganglion expressed TrkA (about 15%), TrkB (about 65%) and TrkC (about 45%). The present results demonstrate that, as in mammals and birds, the inner ear of teleosts expresses the components of the neurotrophin-Trk system, but their roles remain to be elucidated.

Postnatal developmental changes in the expression of ErbB receptors in murine Pacinian cospucles

Neuregulins and their signaling ErbB receptors play a critical role during the development of the mammalian peripheral nervous system, including some kinds of mechanoreceptors such as the Pacinian corpuscles which become structurally and functionally mature postnatally. In this study, we investigated whether or not ErbBs in Pacinian corpuscles undergoes developmental changes, as well as if their expression depends on the innervation. Pacinian corpuscles from 7-day- and 3-month-old mice were assessed for the immunohistochemical detection of EGFR or ErbB1, ErbB2, ErbB3 and ErbB4. The effect of denervation on the expression of ErbBs in mature Pacinian corpuscles was also analyzed. Developing 7-day-old Pacinian corpuscles express ErbB2 and ErbB3 immunoreactivity in the inner-core (regarded as modified Schwann cells), whereas the mature 3-month-old Pacinian corpuscles exclusively displayed ErbB4 immunoreactivity in the outer core and the capsule (regarded as endoneurial and perineurial cells). Denervation was without effect on the ErbB expression. Present results demonstrate maturational related changes and cell segregation in the expression of ErbB receptors by murine Pacinian corpuscles, and that this expression is independent of the innervation.

Evaluation of the antioxidant properties and bioavailability of free and bound phenolic acids from Trichilia emetica Vahl

Trichilia emetica Vahl. is commonly used in folk medicine of Mali for the treatment of various diseases. In this study, the content and the antioxidant activity of phenolic acids from Trichilia emetica root were evaluated. Free phenolic acids were extracted with a mixture of methanol and 10% acetic acid. Bound phenolic acids were released using first alkaline and then acid hydrolysis. All fractions were quantified separately by HPLC. After alkaline hydrolysis, a remarkable increase in caffeic acid, ferulic acid, p-coumaric acid, syringic acid, vanillic acid, protocathecuic acid and gallic acid content was observed, showing that most of phenolic acids in the drug are present as bound forms. Moreover, the extracts submitted to alkaline hydrolysis showed high antioxidant properties in two in vitro assays: autooxidation of methyl linoleate (MeLo) and ascorbate/Fe(2+)-mediated lipid peroxidation in rat microsomes. An in vivo study was also performed to investigate the intestinal absorption of phenolic acids after oral administration of Trichilia emetica extracts. Results showed high levels of phenolic acids, free or conjugated to glucuronide, in the plasma of rats treated with the hydrolyzed extract. Due to the absence of chlorogenic acid in plasma samples, the presence of caffeic acid seems to be derived from hydrolysis of chlorogenic acid in the gastrointestinal tract.

The inclusion complexes of hesperetin and its 7-rhamnoglucoside with (2-hydroxypropyl)-beta-cyclodextrin

The effect of (2-hydroxypropyl)-beta-cyclodextrin (HP-beta-CyD) on the solubility properties and spectroscopic features of hesperetin and its 7-rhamnoglucoside, hesperidin, was qualitatively and quantitatively investigated in water, by means of UV-vis absorption and fluorescence spectroscopy. The stoichiometric ratios and stability constants describing the extent of formation of the complexes have been determined by phase-solubility measurements; in both cases type-A(L) diagrams have been obtained (soluble 1:1 complexes). The higher degree of interaction showed by hesperetin may be attributed to the higher hydrophobicity and smaller size of the aglycone molecule, which therefore exhibits a greater affinity for the CyD and fits better into the cavity. The effect of molecular encapsulation on the two flavanones antioxidant activity was afterwards evaluated by means of different biological assays, concerned to the different mechanisms of in vivo action. The protection efficacy was in all cases higher for the complexed drugs, with respect to the free ones; these results are of great interest for their potential usefulness in pharmaceutics.

Hepatoprotective and antibacterial effects of extracts from Trichilia emetica Vahl. (Meliaceae)

Trichilia emetica Vahl. (Meliaceae) is a tree widely distributed in Tropical Africa. It has been used in Mali folk medicine for the treatment of various illnesses. The aim of this work was to study the hepatoprotective and antibacterial effects of a crude aqueous extract from Trichilia emetica root. An ethyl ether fraction from the aqueous extract was also prepared and studied. We have examined the hepatoprotective activity of the extracts on CCl4-induced damage in rat hepatocytes, their toxicity using the brine shrimp bioassay and their antibacterial activity against clinical isolated bacterial strains, which are commonly responsible for respiratory infections. A preliminary phytochemical analysis showed a high polyphenolic content in the aqueous extract and the presence of limonoids in the ethyl ether fraction. These latter compounds may be considered responsible for the good activity against the bacterial strains tested. Trichilia emetica extracts exerted also a significant (P<0.05) hepatoprotective effect at a dose of 1000 microg/ml both on plasma membrane and mitochondrial function as compared to silymarin used as a positive control. These activities may be a result of the presence of either polyphenols or limonoids. Finally, both the aqueous extract and its ethyl ether fraction did not show toxicity (LC50>1000 microg/ml) in the brine shrimp bioassay.

The rutin/β-cyclodextrin interactions in fully aqueous solution: spectroscopic studies and biological assays

In the present work the feasibility of beta-cyclodextrin complexation was explored, as a tool for improving the aqueous solubility and antioxidant efficacy of rutin. By means of 1H NMR, UV-vis and circular dichroism spectroscopy the single aromatic ring of rutin was found to be inserted into the beta-cyclodextrin cavity to form a 1:1 inclusion complex. The effect of beta-cyclodextrin on the spectral features of rutin was quantitatively investigated, in fully aqueous medium, by holding the concentration of the guest constant and varying the host concentration. The associated binding constants were estimated to be 142+/-20 and 153+/-20 M(-1), respectively, on the basis of the observed UV-vis absorption and circular dichroism intensities. The antioxidant activity of rutin was also investigated, as affected by molecular encapsulation within beta-cyclodextrin (batophenanthroline test; comet assay; lipid peroxidation); the inclusion complex revealed improved antioxidant efficacy that may be in part explained by an increased solubility in the biological moiety.

Effects of alpha- and beta-cyclodextrin complexation on the physico-chemical properties and antioxidant activity of some 3-hydroxyflavones

Inclusion complexes of some flavonols (3-hydroxyflavone, morin and quercetin) have been obtained with alpha- and beta-cyclodextrins, by the co-evaporation method. Different analytical techniques (DSC, XRPD, FT-IR, 1H-NMR, UV-Vis) have been employed for a throughout investigation of the structural characteristics of such supramolecular aggregates, which exhibited distinct spectroscopic features and properties from both "guest" and "host" molecules. The stoichiometric ratios and stability constants describing the extent of formation of the complexes have been determined by phase-solubility studies; in all cases type-AL diagrams have been obtained (soluble 1:1 complexes). The effect of molecular encapsulation on the flavonols antioxidant activity has been afterwards evaluated, by means of different biological assays (Bathophenanthroline test; Comet assay; Lipid peroxidation). Complexation with cyclodextrins further improved the antioxidant activity, increasing drugs solubility in the biological moiety.

Cytotoxicity evaluation after coexposure to perchloroethylene and selected peroxidant drugs in rat hepatocytes

There is evidence of hepatotoxic effects caused by Perchloroethylene (PCE), presumably due to reactive metabolic intermediates; lipid peroxidation is under study as a potential mechanism of toxicity. We aimed to verify if PCE levels comparable to those reached in the blood of exposed subjects can cause cell damage and lipid peroxidation. The association of PCE with lipid peroxidation inducing drugs (cyclosporine A, valproic acid and amiodarone) was also tested on rat isolated hepatocytes. AST and LDH release, MTT test and lipid peroxidation assay showed that PCE determines dose-dependent effects on rat isolated hepatocytes. The toxic potential resulting from our data would be valproic acid < cyclosporine A < amiodarone. While valproic acid and cyclosporine caused a mild toxicity, the effects of amiodarone were more severe; in particular, the association of PCE with amiodarone showed a clear additive effect. The role of lipid peroxidation in the liver toxicity exerted by the tested compounds was confirmed by our data, and resulted relevant after treatment of cells with amiodarone and PCE. Extrapolating these results to human, we can suggest that a subject professionally exposed to PCE, who chronically assumes a lipid peroxidation inducing drug like amiodarone, may be potentially exposed to a higher risk of liver toxicity.

Neurotrophin receptors in taste buds of adult zebrafish (Danio rerio)

TrkB plays crucial roles in the development and maintenance of taste buds in mammals. In this study we investigated the presence and cell localization of Trks (TrkA, TrkB and TrkC) in taste buds of the zebrafish (Danio rerio) using Western blot and immunohistochemistry. Proteins of 140 and 145 kDa, identified as full-length TrkA and TrkB, were detected. Conversely, the anti-TrkC antibody recognized a protein lower than expected (100 kDa). In agreement with these results the sensory cells of taste buds, displayed TrkA- and TrkB-like, but not TrkC-like, immunoreactivity. TrkA and TrkB co-existed in the same taste buds, but remains to be clarified whether or not they are co-expressed in the same cells. Present results demonstrate that as for mammals neurotrophins might play a role in sensory cells of the teleostean taste buds.

The crypt neurons in the olfactory epithelium of the adult zebrafish express TrkA-like immunoreactivity

The olfactory neurons of vertebrates, including teleosts, regenerate through adult life. This ability seems to depend partially on neurotrophic factors, which include some neurotrophins, mainly nerve growth factor (NGF), and their cognate Trk receptors. Zebrafish is an ideal model for studying neurogenesis in the olfactory system, but what kinds of olfactory sensory neurons (ciliated, microvillous or crypt neurons) are under the control of neurotrophins during adult life is unknown. Here we examined the expression of Trk proteins in the olfactory epithelium of adult zebrafish using immunohistochemistry. TrkA-like immunoreactivity was the only Trk detected, and it was restricted to the somata of crypt sensory neurons, their central processes being apparently unreactive. These results provide indirect evidence for a possible role of NGF-like molecules (i.e. neurotrophin-6 and neurotrophin-7) in the peripheral olfactory system of adult zebrafish, acting on TrkA-like receptor expressing crypt neurons. It remains to be established whether or not TrkA-like receptors and their ligands play a function in the neurogenesis or differentiation of these cells.

[Genotoxicity and activation of organophosphate and carbamate pesticides by cytochrome P450 2D6]

The role of the polymorphic cytochrome P450 (CYP) 2D6 isoform in catalysing the oxidative biotransformation of the organophosphate pesticide chlorpyriphos and the carbamate aldicarb into structures that inhibit cholinesterase and induce genotoxicity has been investigated in microsomal fraction, using quinine as a specific chemical inhibitor of CYP 2D6. Pesticides were incubated with rat liver microsomes and production of anticholinergic active metabolites was investigated by the inhibition of human serum cholinesterase. Compared to microsomes incubated without quinine, where cholinesterase activity was inhibited to a mean 53% (chlorpyriphos) and 57% (aldicarb) of control, the introduction of P450 2D6 inhibitor quinine into microsomal incubation mixture reduced cholinesterase activity to 72% of control for chlorpyriphos and to 27% for aldicarb, suggesting that P450 2D6 is involved in the activation of chlorpyriphos but does not influence aldicarb toxicity on acetylcholinesterase. Moreover, the potential genotoxicity of these compounds was evaluated by single cell gel electrophoresis (comet assay) on human leucocytes. DNA fragmentation compared to control was markedly increased after incubation with aldicarb plus quinine, confirming that the parent compound is more toxic than the products of CYP metabolism; conversely, DNA damage after incubation with chlorpyriphos was sensibly reduced by quinine indicating the metabolic activation of this pesticide by CYP 2D6. These data suggest that polymorphism of CYP 2D6 can influence the toxicity of organophosphate but not of carbamate pesticides.

S-100 protein is a selective marker for sensory hair cells of the lateral line system in teleosts

The distribution of S100 protein in the neuromast of the lateral line system (LLS) was investigated immunohistochemically in alevins of three species of teleosts (Salmo trutta, Salmo salar and Dicentrarchus labrax), using a polyclonal antibody. In both the neuromasts of the canals, as well as in the pit organs, the hair cells, regarded as the specific sensory cells, displayed cytoplasmic immunoreactivity for S100 protein. Conversely, the supporting cells, mantle cells and basal cells were devoid of immunoreaction. These results demonstrate for the first time the occurrence of S100 in the LLS of teleosts. Due to the cell specific localization, this protein might serve as a marker for sensory hair cells in neuromasts.

Immunohistochemical localization of BDNF-, TrkB- and TrkA-like proteins in the teleost lateral line system

The lateral line system, formed of both superficial (pit organs) and canal neuromasts, is one of the major mechanosensory systems in fish. It has always been assumed that this system depends on neurotrophins and their cognate Trk receptors for development and maintenance, as has been shown in other mechanosensitive systems of vertebrates. However, until nowthis issue has not been specifically addressed. In this study we used immunohistochemistry to investigate the occurrence and localization both of neurotrophins (NGF-, BDNF- and NT-3-like) and of Trk-like proteins (TrkA-, TrkB-, TrkC-like) in alevins of Salmo salar and S. trutta. All cells in the pit organs of S. salar displayed strong immunoreactivity for TrkB-like and BDNF-like, whereas they were restricted to the hair cells in S. trutta. The hair, supporting and mantle cells of S. salar, and the mantle cells of S. trutta, also expressed TrkA-like immunoreactivity. In the canal neuromasts BDNF-, TrkA- and TrkB-like proteins were present in all cells, without differences between species. NGF-, NT-3- and TrkC-like immunoreactivity were never detected. The present results suggest that mechanoreceptive hair cells, as well as supporting cells, in the lateral line system are under the control of the BDNF-TrkB-like complex, and probably of ligands of TrkA-like receptors.

[Breast inflammations: clinical observations and principles of treatment]

In this study some clinical and etiopathogenetic principles, and the most appropriate treatment for breast inflammation are discussed. In the majority of cases, differential diagnosis is made not only through clinical diagnosis but also through cytological examination and ultrasonography. Of the forms reported, we considered the different inflammatory, glandular and extraglandular, peripheral and central mastites; among the latter in particular periductal mastitis and duct ectasia. Medical treatment is the answer for some forms, while for others, as for example mammillary fistula, we prefer, in agreement with some authors, the surgery of fistulectomy and healing by first intention; for the peripheral abscesses we prefer US-guided percutaneous drainage. This article stresses the importance of clinical diagnosis, pathogenetic history, and adequate treatment in efforts to improve both the knowledge of the surgeon and the quality of life of the patient.

Treatment of dystonic clenched fist with botulinum toxin

Fourteen patients with "dystonic clenched fist" (three with Corticobasal Ganglionic Degeneration, seven with Parkinson's disease, and four with Dystonic-Complex Regional Pain Syndrome) were treated with botulinum toxin A (BTXA, Dysport). The muscles involved were identified by the hand posture and EMG activity recorded at rest and during active and passive flexion/extension movements of the finger and wrist. EMG was useful in distinguishing between muscle contraction and underlying contractures and to determine the dosage of BTX. All patients had some degree of flexion at the proximal metacarpophalangeal joints and required injections into the lumbricals. The response in patients depended on the severity of the deformity and the degree of contracture. All patients had significant benefit to pain, with accompanying muscle relaxation, and palmar infection, when present, was eradicated. Four patients with Parkinson's disease and one patient with Dystonia-Complex Regional Pain Syndrome obtained functional benefit.

Neurotrophin receptor-like proteins in the bovine (Bos taurus) lymphoid organs, with special reference to thymus and spleen

Increasing evidence suggests that neurotrophins could regulate immune functions acting directly or indirectly on immunocompetent cells. The indirect pathway involves stromal cells of the primary and secondary lymphoid organs. In the present study the occurrence of Trk proteins (TrkA, TrkB and TrkC), regarded as the high-affinity signal-transducing receptors for neurotrophins, was investigated in cow lymphoid organs using immunohistochemistry. The thymus and spleen of both fetal and adult animals, and the palatine tonsils, lymph nodes and Peyer's patches of adult animals, were analysed. Unidentified cells displaying TrkA-like immunoreactivity were found in the fetal thymus, whereas those expressing this protein in the adult gland were identified as epithelial cells. In the spleen, immunoreactive TrkA was observed in cells of the white pulp. TrkB immunoreactivity in both fetal and adult thymus and spleen was localized in monocyte/macrophage cells. As a rule, TrkC was absent from the thymus and the spleen independent of the animal's age. Different types of stromal cells, but never the lymphocytes themselves, displayed TrkA, TrkB, or TrkC immunoreactivity in the other lymphoid organs analysed. As in other vertebrate species, Trk proteins in the lymphoid organs of the cow were localized in the stromal, non-lymphoid cells, thus suggesting that neurotrophins might regulate the immune function acting indirectly on lymphocytes.

Cellular and noncellular components of bronchoalveolar lavage fluid in HIV-1-infected children with radiological evidence of interstitial lung damage

Children with acquired immune deficiency syndrome (AIDS) commonly have recurrent infectious and noninfectious lung complications that ultimately end in death. To study the intensity of alveolar inflammation and to evaluate the clinical utility of bronchoalveolar lavage (BAL) in children with HIV-1 infections, we retrospectively analyzed differential cell counts, lymphocyte subsets, and fibronectin and hyaluronic acid concentrations in BAL fluid of 18 HIV-1-positive children (9 boys, mean age 3.5 years, range 5 months-8 years) with radiological evidence of interstitial lung disease, and 19 control children who had undergone BAL for clinical indications not involving the lung parenchyma (13 boys, mean age 3 years, range 2 months-14 years). BAL fluid from 89% of the HIV-1 infected children showed CD8+ve lymphocytic alveolitis expressing HLA-DR, CD54, and CD 69 antigens. BAL fluid from HIV-infected patients typically contained markedly increased percentages and numbers of lymphocytes (P < 0.0001) and eosinophils (P < 0.04) and significantly higher concentrations of albumin (P < 0.05) and fibronectin (P < 0.0006) than fluids from control children. Whereas BAL cellular components did not differ in P. carinii-positive and P. carinii-negative HIV-1-infected children, fibronectin concentrations were significantly higher in P. carinii-positive than negative children. BAL cell differentials and noncellular components were related neither to severity of disease nor to patients' disease progression. These findings indicate that BAL is useful in studying the intensity of lung inflammation in children with HIV-1 infections and radiologically documented interstitial lung disease, but provides no information on the subsequent clinical course.

Trk neurotrophin receptor-like proteins in the teleost Dicentrarchus labrax

In recent years, data have accumulated suggesting that the role of neurotrophins and Trk receptors may not be limited to the nervous system, and the presence of these substances has been detected in a variety of vertebrate and invertebrate non-nervous tissues. This study was designed to map the expression of immunoreactivity (IR) for Trk-like proteins in alevins of the teleost Dicentrarchus labrax, with particular emphasis on non-nervous structures. We used antibodies against specific epitopes of the intracellular domain of these proteins, a region that is highly conserved in phylogeny. Trk-like IR was seen in segregate cell populations of the nervous system, and non-nervous tissues. In the central nervous system TrkA-like and TrkC-like IR was abundant, whereas TrkB-like IR was restricted to a low number of brain areas. Expression of Trk-like protein IR was observed in the peripheral nervous system and sensory organs, with the exception of the lateral line organ. Outside the nervous system, TrkA-like IR was mainly found in different epithelia, TrkB-like IR in the endocrine and digestive system, and TrkC-like IR in the cardiovascular and immune systems. The gills showed IR for all three Trk-like proteins, whereas they were absent from the gonads. Furthermore, scattered cells positive for Trk-like proteins were found in most of the investigated tissues. The distribution of Trk-like IR in this teleost is compared with that of mammals and birds, which it often paralleled, and the possible role of neurotrophins and Trk-like receptor proteins in different non-neuronal tissues is discussed.

Paradoxic reaction to lamotrigine in a child with benign focal epilepsy of childhood with centrotemporal spikes

A girl aged 5 years developed nocturnal seizures (mouth twitching, salivation, anarthria, with right arm jerking and occasional secondary generalisation), with frequent focal sharp waves over the left centrotemporal region in her EEG, suggesting benign childhood epilepsy with centrotemporal spikes (BECTS). Seizures became diurnal and frequent, not modified by carbamazepine (CBZ) or valproate (VPA) but responding to VPA and lamotrigine (LTG) with recommended dosage schedules for this combination. Her school performance then deteriorated insidiously, with poor memory and concentration, clumsiness, stuttering, and emotional lability. After 4 months, new episodes, < or =10 per day, occurred. These lasted a few seconds; she stared into space, her jaw dropped, her head dropped to the right, and her eyelids flickered. She usually maintained awareness. Attacks were often provoked by blowing or sneezing. Ictal EEG showed anterior-predominant 3/s sharp-slow wave complexes lasting < or =8 s, with bilateral rolandic discharges interictally. Withdrawal of LTG resulted in rapid improvement in cognitive function and gradual remission of the new attacks.

CONCLUSIONS

This appears to be a paradoxic reaction to LTG in the setting of BECTS.