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1.
Crit Rev Oncol Hematol ; 200: 104404, 2024 May 28.
Article in English | MEDLINE | ID: mdl-38815877

ABSTRACT

The results of the SOLAR-1 and CAPItello-291, highlight the benefit of the ɑ-selective phosphoinositide 3-Kinase Pathway inhibitor (PI3Ki) alpelisib and the AKT inhibitor (AKTi) capivasertib in patients with hormone receptor-positive (HR+)/Human Epidermal Growth Factor Receptor 2 (HER2)- negative metastatic breast cancer (mBC) that have PIK3CA/AKT1/PTEN tumour alterations. Although effective, these drugs are associated with significant toxicities, which often limit their use, particularly in frail patients. Following the recent incorporation of these agents into clinical practice, and with many others currently in development, significant challenges have emerged, particularly those regarding biomarkers for patient selection. This review will discuss biomarkers of response and their resistance to PI3K/AKT inhibitors (PI3K/AKTis) in HR+/HER- BC in early and advanced settings to ascertain which populations will most benefit from these drugs. Of the biomarkers that were analysed, such as PIK3CA, AKT, PTEN mutations, insulin levels, 18 F-FDG-PET/TC, only the PIK3CA-mutations (PIK3CA-mut) and the AKT pathway alterations seem to have a predictive value for treatments with alpelisib and capivasertib. However, due to the retrospective and exploratory nature of the study, the data did not provide conclusive results. In addition, the different methods used to detect PIK3CA/AKT1/PTEN alterations underline the fact that the optimal diagnostic companion has yet to be established. We have summarised the clinical data on the approved and discontinued agents targeting this pathway and have assessed the drugs development, successes, and failures. Finally, because of tumour heterogeneity, we emphasise the importance of reassessing the mutational status of PI3KCA in both metastatic tissue and blood at the time of disease progression to better tailor treatment for patients.

2.
ESMO Open ; 8(6): 102036, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37866028

ABSTRACT

BACKGROUND: Baseline plasma androgen-receptor copy number (AR-CN) is a promising biomarker for metastatic castration-resistant prostate cancer (mCRPC) outcome and treatment response; however, the role of its longitudinal testing is unproven. We aimed to evaluate the prognostic role of AR-CN assessed before subsequent treatment lines in mCRPC patients. METHODS: A subgroup analysis of a prospective multicenter biomarker trial (IRSTB030) was carried out. Plasma AR-CN status (classified as normal or gain, cut-off value = 2) was assessed with digital PCR before each treatment line. RESULTS: Forty mCRPC patients receiving sequentially docetaxel, cabazitaxel and an AR signaling inhibitor (abiraterone or enzalutamide) were analyzed. At multivariate analysis, at each assessment overall survival (OS) was independently correlated with AR-CN status [first line: hazard ratio (HR) 4.1 [95% confidence interval (CI) 1.6-10.5]; second line: HR 2.4 (95% CI 1.1-5.3); third line: HR 2.1 (95% CI 1.0-4.3)] and median prostate-specific antigen [first line: HR 4.4 (95% CI 1.8-10.9); second line: HR 3.4 (95% CI 1.6-7.2); third line: HR 2.5 (95% CI 1.2-5.6)]. In the three subsequent assessments, AR-CN status changed from normal to gain in 15 (38%) patients. These patients had longer OS (47 months) compared with patients presenting AR-CN gain from first assessment (36 months), but shorter than those maintaining normal AR-CN (69 months) (P = 0.003). CONCLUSIONS: Plasma AR-CN correlates with survival not only at baseline (before first treatment), but also in the assessments before the following lines. Interestingly, AR-CN status may change from normal to gain across subsequent treatments in a significant number of cases, identifying a group of patients with intermediate outcomes. Longitudinal assessment of AR-CN status could represent a promising method to capture mCRPC intrinsic heterogeneity and to improve clinical management.


Subject(s)
Prostatic Neoplasms, Castration-Resistant , Receptors, Androgen , Male , Humans , Receptors, Androgen/genetics , Receptors, Androgen/therapeutic use , Prostatic Neoplasms, Castration-Resistant/drug therapy , Prostatic Neoplasms, Castration-Resistant/genetics , DNA Copy Number Variations , Prospective Studies , Prostate-Specific Antigen/therapeutic use
3.
Clin Neurophysiol ; 132(9): 2191-2198, 2021 09.
Article in English | MEDLINE | ID: mdl-34293529

ABSTRACT

OBJECTIVE: To explore whether abnormal thalamic resting-state functional connectivity (rsFC) contributes to altered sensorimotor integration and hand dexterity impairment in multiple sclerosis (MS). METHODS: To evaluate sensorimotor integration, we recorded kinematic features of index finger abductions during somatosensory temporal discrimination threshold (STDT) testing in 36 patients with relapsing-remitting MS and 39 healthy controls (HC). Participants underwent a multimodal 3T structural and functional MRI protocol. RESULTS: Patients had lower index finger abduction velocity during STDT testing compared to HC. Thalamic rsFC with the precentral and postcentral gyri, supplementary motor area (SMA), insula, and basal ganglia was higher in patients than HC. Intrathalamic rsFC and thalamic rsFC with caudate and insula bilaterally was lower in patients than HC. Finger movement velocity positively correlated with intrathalamic rsFC and negatively correlated with thalamic rsFC with the precentral and postcentral gyri, SMA, and putamen. CONCLUSIONS: Abnormal thalamic rsFC is a possible substrate for altered sensorimotor integration in MS, with high intrathalamic rsFC facilitating finger movements and increased thalamic rsFC with the basal ganglia and sensorimotor cortex contributing to motor performance deterioration. SIGNIFICANCE: The combined study of thalamic functional connectivity and upper limb sensorimotor integration may be useful in identifying patients who can benefit from early rehabilitation to prevent upper limb motor impairment.


Subject(s)
Magnetic Resonance Imaging/methods , Multiple Sclerosis, Relapsing-Remitting/diagnostic imaging , Multiple Sclerosis, Relapsing-Remitting/physiopathology , Psychomotor Performance/physiology , Sensory Gating/physiology , Adult , Female , Humans , Male , Middle Aged , Nerve Net/diagnostic imaging , Nerve Net/physiopathology , Prospective Studies , Sensorimotor Cortex/diagnostic imaging , Sensorimotor Cortex/physiopathology , Thalamus/diagnostic imaging , Thalamus/physiopathology
4.
Clin Neurophysiol ; 132(5): 1151-1156, 2021 05.
Article in English | MEDLINE | ID: mdl-33774380

ABSTRACT

OBJECTIVE: Motor surround inhibition (mSI) is a physiological mechanism that contributes to hand movement control by focusing voluntary movement. Growing evidence suggests that hand movement control is impaired in multiple sclerosis. The aim of the study was to evaluate mSI in MS and to investigate the brain structures involved in mSI in multiple sclerosis. METHODS: We recruited 33 patients and 23 controls. To investigate mSI, we delivered transcranial magnetic single pulses during index finger flexion. Motor evoked potentials were recorded and first dorsal interosseous ("active muscle") and from the abductor digiti minimi ("surround muscle"). mSI was expressed as the ratio between Motor evoked potentials recorded from the surround muscle during movement and at rest. Participants underwent a magnetic resonance study. RESULTS: Patients had impaired mSI as compared with controls. Magnetic resonance showed that basal ganglia had smaller volumes and higher mean diffusivity than controls. Impaired mSI correlated with primary motor cortex and basal ganglia involvement in multiple sclerosis. CONCLUSION: Altered mSI in multiple sclerosis is related to cortical and subcortical grey matter involvement. SIGNIFICANCE: Our study provides the first demonstration of a pathophysiological mechanism underlying hand movement control dysfunction in multiple sclerosis. mSI represents a new therapeutic target of multiple sclerosis rehabilitative approaches.


Subject(s)
Gray Matter/physiopathology , Motor Cortex/physiopathology , Multiple Sclerosis/physiopathology , Neural Inhibition , Adult , Basal Ganglia/physiopathology , Evoked Potentials, Motor , Female , Humans , Male , Middle Aged , Muscle, Skeletal/physiopathology
5.
G Ital Dermatol Venereol ; 150(4): 357-62, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25854670

ABSTRACT

AIM: Moderate and chronic paronychia is a common disease affecting the hand. Treatment can be effective but the affection is often recurrent, especially as an occupational disease. Moreover, this condition may be complicated by a Candida spp or by bacterial infections. Therefore, general preventive measures can be useful in maintaining health. The aim of this study was to investigate the efficacy and tolerability of a new combination of topical medications in the treatment and prevention of moderate and chronic paronychia. This formulation includes an insulating polymer (Syn-cell barrier), two topical antifungals (octopirox and climbazole) and a molecule with anti-inflammatory activity (corticoid-like repair). METHODS: Thirty adult subjects (age, 16-78 years; 24 females and 6 males) affected by moderate or chronic paronychia, with or without nail alterations, were evaluated. Included in the study were patients with allergic contact dermatitis (8), irritant contact dermatitis (19), psoriatic paronychia (2 patients), lichen planus of the nails (1 patient). Sometimes Candida spp or bacteria overlapped with paronychia (16 patients positive for Candida spp and 4 patients with bacterial paronychia), sometimes infectious paronychia was not associated with dermatitis of the hands. All 30 subjects were treated with a new cream formulation, three applications per day for 2 months. In 8 patients with proven and severe candidiasis of the nails, oral fluconazole 100 mg was added for 20 days. All patients with bacterial perionyxis took clarithromycin 500 mg twice daily for six days. Patients were then followed for 8 weeks. RESULTS: After two months of treatment, 26 patients responded to therapy. In particular, the treatment evaluation at the end of the follow-up period showed a clinical cure in 46.6% (14 patients), improvement in 40% (12 patients), and failure in 13.4% (4 patients). There was a side effect (moderate skin irritation) in 2 patients, but the drug was not discontinued. CONCLUSION: Results of the present study, based on its safety, effectiveness and innovative features, indicate that this combination of topical cream may be considered as a new alternative for treatment and prevention of paronychia, especially in case of occupational hand disease where prolonged treatment and continuous prevention are needed.


Subject(s)
Antifungal Agents/therapeutic use , Dermatologic Agents/therapeutic use , Nail Diseases/drug therapy , Paronychia/drug therapy , Administration, Topical , Adolescent , Adult , Aged , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/therapeutic use , Anti-Inflammatory Agents/administration & dosage , Anti-Inflammatory Agents/adverse effects , Anti-Inflammatory Agents/therapeutic use , Antifungal Agents/administration & dosage , Antifungal Agents/adverse effects , Chronic Disease , Clarithromycin/administration & dosage , Clarithromycin/therapeutic use , Dermatologic Agents/administration & dosage , Dermatologic Agents/adverse effects , Drug Combinations , Drug Therapy, Combination , Ethanolamines/administration & dosage , Ethanolamines/adverse effects , Ethanolamines/therapeutic use , Female , Fluconazole/administration & dosage , Fluconazole/therapeutic use , Follow-Up Studies , Humans , Imidazoles/administration & dosage , Imidazoles/adverse effects , Imidazoles/therapeutic use , Male , Middle Aged , Nail Diseases/pathology , Nail Diseases/prevention & control , Occupational Diseases/drug therapy , Occupational Diseases/pathology , Occupational Diseases/prevention & control , Paronychia/pathology , Paronychia/prevention & control , Polymers/administration & dosage , Polymers/chemistry , Pyridones/administration & dosage , Pyridones/adverse effects , Pyridones/therapeutic use , Young Adult
6.
J Med Food ; 17(9): 979-84, 2014 Sep.
Article in English | MEDLINE | ID: mdl-24892475

ABSTRACT

The present study aimed to evaluate the toxicity of aqueous extract of Chenopodium ambrosioides leaves. To measure acute toxicity, rats were administered 0, 0.3, 1.0, or 3.0 g/kg of aqueous extract from C. ambrosioides leaves by gavage. To analyze sub-chronic toxicity, rats were treated by oral gavage for 15 consecutive days with 0, 0.3, or 1.0 g/kg of extract of C. ambrosioides leaves. No animals from either trial exhibited any signs of toxicity. In the acute study, the highest dose of the extract led to an increase in the serum activities of alanine transaminase (ALT) and aspartate transaminase (AST) and a decrease in the serum levels of urea. In the sub-chronic test, rats treated with 1.0 g/kg for 15 days exhibited increased serum ALT activity and creatinine levels and mild cytoplasmic vacuolation of hepatocytes. The results indicate that aqueous extract from C. ambrosioides leaves produce slight hepatotoxic lesions in rats.


Subject(s)
Chenopodium ambrosioides/adverse effects , Liver/drug effects , Plant Extracts/adverse effects , Alanine Transaminase/blood , Animals , Aspartate Aminotransferases/blood , Creatinine/blood , Liver/pathology , Male , Plant Leaves , Rats, Wistar , Urea/blood
7.
G Ital Dermatol Venereol ; 148(6): 633-8, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24442043

ABSTRACT

Onychomycosis is a fungal infection of the nail which is highly prevalent in the general population, particularly among older individuals. Patients seek care because the disease is infectious or simply for an esthetic discomfort. The difficulty in treating onychomycosis results from the deep-seated nature of the infection within the nail unit and the inability of drugs to effectively reach all sites. Present treatment options include both oral and topical drugs, with oral therapies giving better outcomes. New derivatives with a favorable risk-benefit ratio and new formulations of older azoles seem to be promising. The research for new drugs or formulations has the objective of discovering new active antifungals or new technologies to facilitate incorporation or persistence of existing antifungal drugs inside the nail plate. In fact, the same antimycotics that heal skin fungal infections are rendered less efficacious in nail disease. This update has the aim to synthesize and focus the therapies currently in use and new therapeutic approaches on onychomycosis. It also summarizes the newer areas of research in the treatment of onychomycosis as photodynamic and laser therapy.


Subject(s)
Antifungal Agents/therapeutic use , Onychomycosis/diagnosis , Onychomycosis/therapy , Trichophyton , Administration, Cutaneous , Administration, Oral , Humans , Italy/epidemiology , Laser Therapy/methods , Onychomycosis/epidemiology , Onychomycosis/microbiology , Photochemotherapy/methods , Prevalence , Severity of Illness Index , Treatment Outcome , Trichophyton/isolation & purification
8.
J Biomed Mater Res B Appl Biomater ; 100(6): 1490-9, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22689286

ABSTRACT

Ti oxides formed naturally on Nitinol surfaces are only a few nanometers thick. To increase their thickness, heat treatments are explored. The resulting surfaces exhibit poor resistance to pitting corrosion. As an alternative approach to accelerate surface oxidation and grow thicker oxides, the exposure of Nitinol to strong oxidizing H(2)O(2) aqueous solutions (3 and 30%) for various periods of time was used. Using X-Ray Photoelectron Spectroscopy (XPS) and Auger spectroscopy, it was found that the surface layers with variable Ti (6-15 at %) and Ni (5-13 at %) contents and the thickness up to 100 nm without Ni-enriched interfaces could be formed. The response of the surface oxides to stress in superelastic regime of deformations depended on oxide thickness. In the corrosion studies performed in both strained and strain-free states using potentiodynamic and potentiostatic polarizations, the surfaces treated in H(2)O(2) showed no pitting in corrosive solution that was assigned to higher chemical homogeneity of the surfaces free of secondary phases and inclusions that assist better biocompatibility of Nitinol medical devices.


Subject(s)
Alloys/chemistry , Hydrogen Peroxide/chemistry , Materials Testing , Titanium/chemistry , Corrosion , Photoelectron Spectroscopy
9.
Eur J Neurol ; 19(5): 783-7, 2012 May.
Article in English | MEDLINE | ID: mdl-22054236

ABSTRACT

BACKGROUND AND PURPOSE: Temporary discontinuation of natalizumab is sometimes considered as the observed risk of progressive multifocal leukoencephalopathy (PML) in patients with multiple sclerosis (MS). However, interruption of natalizumab may result in a re-start of disease activity. METHODS: In this prospective post-marketing study, 23 patients with MS treated with natalizumab elected a trial of treatment interruption (90-150 days) because of safety concerns on the risk of developing PML. To reduce the risk of disease activity return, patients received monthly intravenous (i.v.) steroid pulses before natalizumab re-start. RESULTS: Despite the steroid coverage, seven patients (30.4%) had an active scan during the natalizumab interruption period; of these, four also had a concomitant clinical exacerbation. CONCLUSIONS: Our findings suggest that i.v. steroids are not currently recommendable as drug coverage during a scheduled treatment interruption period.


Subject(s)
Antibodies, Monoclonal, Humanized/therapeutic use , Immunologic Factors/therapeutic use , Multiple Sclerosis/drug therapy , Product Surveillance, Postmarketing , Adult , Disability Evaluation , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Natalizumab , Prospective Studies , Retrospective Studies , Severity of Illness Index , Statistics, Nonparametric
10.
J Virol ; 85(10): 4761-71, 2011 May.
Article in English | MEDLINE | ID: mdl-21389136

ABSTRACT

Mammalian retrotransposons, transposable elements that are processed through an RNA intermediate, are categorized as short interspersed elements (SINEs), long interspersed elements (LINEs), and long terminal repeat (LTR) retroelements, which include endogenous retroviruses. The ability of transposable elements to autonomously amplify led to their initial characterization as selfish or junk DNA; however, it is now known that they may acquire specific cellular functions in a genome and are implicated in host defense mechanisms as well as in genome evolution. Interactions between classes of transposable elements may exert a markedly different and potentially more significant effect on a genome than interactions between members of a single class of transposable elements. We examined the genomic structure and evolution of the kangaroo endogenous retrovirus (KERV) in the marsupial genus Macropus. The complete proviral structure of the kangaroo endogenous retrovirus, phylogenetic relationship among relative retroviruses, and expression of this virus in both Macropus rufogriseus and M. eugenii are presented for the first time. In addition, we show the relative copy number and distribution of the kangaroo endogenous retrovirus in the Macropus genus. Our data indicate that amplification of the kangaroo endogenous retrovirus occurred in a lineage-specific fashion, is restricted to the centromeres, and is not correlated with LINE depletion. Finally, analysis of KERV long terminal repeat sequences using massively parallel sequencing indicates that the recent amplification in M. rufogriseus is likely due to duplications and concerted evolution rather than a high number of independent insertion events.


Subject(s)
Centromere/virology , Endogenous Retroviruses/genetics , Endogenous Retroviruses/isolation & purification , Macropodidae/virology , Animals , Evolution, Molecular , Gene Expression Profiling , High-Throughput Nucleotide Sequencing , Phylogeny , Proviruses/genetics , Proviruses/isolation & purification , Sequence Analysis, DNA
11.
G Ital Dermatol Venereol ; 145(3): 415-24, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20461049

ABSTRACT

Terbinafine, a synthetic antifungal of allylamine class, has fungicidal activity against dermatophytes, moulds and certain dimorphic fungi and fungistatic activity against Candida albicans. Following oral administration the terbinafine is absorbed rapidly (>70%) and reaches within 2 hours the peak plasma concentration. The drug is highly lipophilic and keratophilic and is highly bound to plasma protein (>90%) with a bioavailability of 70% to 80%. The drug is rapidly delivered and it is present in the stratum corneum, sebum, nails and hair for months after stopping the medication. The drug has been proven to be the choice treatment in the therapy of onychomycosis as it is very effective, well tolerated and has a relatively low potential for drug interactions. The pharmacologic and pharmacokinetic properties of terbinafine give strong support to the possibility that the pulse therapy may be equally effective in onychomycoses, possibly reducing medication costs and drug exposure. Several therapeutic patterns have been proposed: weekly intermittent terbinafine (500 mg/d for 1 week each month for 4 months), or single-dose terbinafine (1000 mg per month for 4 months). Use of topical terbinafine 1% may be practical where the tinea involvement is not extensive or chronic. Recently, the terbinafine is available in a novel topical solution (film-forming solution--FFS) effective in the treatment of tinea pedis (athlete's foot).


Subject(s)
Antifungal Agents/therapeutic use , Dermatomycoses/drug therapy , Naphthalenes/therapeutic use , Humans , Terbinafine
12.
Biomaterials ; 30(22): 3662-71, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19345407

ABSTRACT

The present study explored the avenues for the improvement of native Nitinol surfaces for implantation obtained using traditional procedures such as mechanical polishing, chemical etching, electropolishing and heat treatments for a better understanding of their electrochemical behavior and associated surface stability, conductivity, reactivity and biological responses. The corrosion resistance (cyclic potential polarization, open circuit potential and polarization resistance) of Nitinol disc and wire samples were evaluated for various surface states in strain-free and strained wire conditions. The surface response to tension strain was studied in situ. Surface chemistry and structure were explored using XPS and Auger spectroscopy and photoelectrochemical methods, respectively. It was found that the polarization resistance of the Nitinol surfaces varied in a range from 100 kOmega to 10 MOmega cm(2) and the open circuit potentials from -440 mV to -55 mV. The surfaces prepared in chemical solutions showed consistent corrosion resistance in strain-free and strained states, but mechanically polished and heat treated samples were prone to pitting. Nitinol surface oxides are semiconductors with the band gaps of either 3.0 eV (rutile) or 3.4 eV (amorphous). The conductivity of semiconducting Nitinol surfaces relevant to their biological performances is discussed in terms of oxide stoichiometry and variable Ni content. Such biological characteristics of Nitinol surfaces as Ni release, fibrinogen adsorption and platelets behavior are re-examined based on the analysis of the results of the present study.


Subject(s)
Alloys/chemistry , Biocompatible Materials/chemistry , Electrochemical Techniques , Corrosion , Materials Testing , Solutions/chemistry , Surface Properties
13.
Chromosoma ; 118(1): 113-25, 2009 Feb.
Article in English | MEDLINE | ID: mdl-18839199

ABSTRACT

The transcriptional framework of the eukaryotic centromere core has been described in budding yeast and rice, but for most eukaryotes and all vertebrates it remains largely unknown. The lack of large pericentric repeats in the tammar wallaby has made it possible to map and identify the transcriptional units at the centromere in a mammalian species for the first time. We show that these transcriptional units, comprised of satellites and a retrovirus, are bound by centromere proteins and that they are the source of a novel class of small RNA. The endogenous retrovirus from which these small RNAs are derived is now known to be in the centromere domain of several vertebrate classes. The discovery of this new RNA form brings together several independent lines of evidence that point to a conserved retroviral-encoded processed RNA entity within eukaryotic centromeres.


Subject(s)
Centromere/genetics , Mammals/genetics , RNA, Satellite/genetics , RNA, Satellite/metabolism , Retroviridae/physiology , Animals , Cells, Cultured , Centromere/physiology , Chromosomes/genetics , Chromosomes, Artificial, Bacterial , Fibroblasts , In Situ Hybridization, Fluorescence , Mammals/metabolism , Mice , Retroelements/genetics , Retroelements/physiology , Retroviridae/genetics , Transcription, Genetic
14.
BMC Genomics ; 9: 205, 2008 May 02.
Article in English | MEDLINE | ID: mdl-18454865

ABSTRACT

BACKGROUND: Parent-specific methylation of specific CpG residues is critical to imprinting in eutherian mammals, but its importance to imprinting in marsupials and, thus, the evolutionary origins of the imprinting mechanism have been the subject of controversy. This has been particularly true for the imprinted Insulin-like Growth Factor II (IGF2), a key regulator of embryonic growth in vertebrates and a focal point of the selective forces leading to genomic imprinting. The presence of the essential imprinting effector, DNMT3L, in marsupial genomes and the demonstration of a differentially methylated region (DMR) in the retrotransposon-derived imprinted gene, PEG10, in tammar wallaby argue for a role for methylation in imprinting, but several studies have found no evidence of parent-specific methylation at other imprinted loci in marsupials. RESULTS: We performed the most extensive search to date for allele-specific patterns of CpG methylation within CpG isochores or CpG enriched segments across a 22 kilobase region surrounding the IGF2 gene in the South American opossum Monodelphis domestica. We identified a previously unknown 5'-untranslated exon for opossum IGF2, which is flanked by sequences defining a putative neonatal promoter, a DMR and an active Matrix Attachment Region (MAR). Demethylation of this DMR in opossum neonatal fibroblasts results in abherrant biallelic expression of IGF2. CONCLUSION: The demonstration of a DMR and an active MAR in the 5' flank of opossum IGF2 mirrors the regulatory features of the 5' flank of Igf2 in mice. However, demethylation induced activation of the maternal allele of IGF2 in opossum differs from the demethylation induced repression of the paternal Igf2 allele in mice. While it can now be concluded that parent-specific DNA methylation is an epigentic mark common to Marsupialia and Eutheria, the molecular mechanisms of transcriptional silencing at imprinted loci have clearly evolved along independent trajectories.


Subject(s)
DNA Methylation , Genomic Imprinting , Insulin-Like Growth Factor II/genetics , Opossums/genetics , Animals , Biological Evolution , DNA (Cytosine-5-)-Methyltransferases , Inheritance Patterns , Marsupialia/genetics
15.
Genetics ; 177(4): 2507-17, 2007 Dec.
Article in English | MEDLINE | ID: mdl-18073443

ABSTRACT

Several lines of evidence suggest that, within a lineage, particular genomic regions are subject to instability that can lead to specific types of chromosome rearrangements important in species incompatibility. Within family Macropodidae (kangaroos, wallabies, bettongs, and potoroos), which exhibit recent and extensive karyotypic evolution, rearrangements involve chiefly the centromere. We propose that centromeres are the primary target for destabilization in cases of genomic instability, such as interspecific hybridization, and participate in the formation of novel chromosome rearrangements. Here we use standard cytological staining, cross-species chromosome painting, DNA probe analyses, and scanning electron microscopy to examine four interspecific macropodid hybrids (Macropus rufogriseus x Macropus agilis). The parental complements share the same centric fusions relative to the presumed macropodid ancestral karyotype, but can be differentiated on the basis of heterochromatic content, M. rufogriseus having larger centromeres with large C-banding positive regions. All hybrids exhibited the same pattern of chromosomal instability and remodeling specifically within the centromeres derived from the maternal (M. rufogriseus) complement. This instability included amplification of a satellite repeat and a transposable element, changes in chromatin structure, and de novo whole-arm rearrangements. We discuss possible reasons and mechanisms for the centromeric instability and remodeling observed in all four macropodid hybrids.


Subject(s)
Centromere , Chimera/genetics , Genomic Instability , Marsupialia/genetics , Animals , Chromatin Assembly and Disassembly , DNA Transposable Elements , Gene Rearrangement , Karyotyping , Species Specificity
16.
Genome Biol ; 8(8): R170, 2007.
Article in English | MEDLINE | ID: mdl-17708770

ABSTRACT

BACKGROUND: It has been hypothesized that rapid divergence in centromere sequences accompanies rapid karyotypic change during speciation. However, the reuse of breakpoints coincident with centromeres in the evolution of divergent karyotypes poses a potential paradox. In distantly related species where the same centromere breakpoints are used in the independent derivation of karyotypes, centromere-specific sequences may undergo convergent evolution rather than rapid sequence divergence. To determine whether centromere sequence composition follows the phylogenetic history of species evolution or patterns of convergent breakpoint reuse through chromosome evolution, we examined the phylogenetic trajectory of centromere sequences within a group of karyotypically diverse mammals, macropodine marsupials (wallabies, wallaroos and kangaroos). RESULTS: The evolution of three classes of centromere sequences across nine species within the genus Macropus (including Wallabia) were compared with the phylogenetic history of a mitochondrial gene, Cytochrome b (Cyt b), a nuclear gene, selenocysteine tRNA (TRSP), and the chromosomal histories of the syntenic blocks that define the different karyotype arrangements. Convergent contraction or expansion of predominant satellites is found to accompany specific karyotype rearrangements. The phylogenetic history of these centromere sequences includes the convergence of centromere composition in divergent species through convergent breakpoint reuse between syntenic blocks. CONCLUSION: These data support the 'library hypothesis' of centromere evolution within this genus as each species possesses all three satellites yet each species has experienced differential expansion and contraction of individual classes. Thus, we have identified a correlation between the evolution of centromere satellite sequences, the reuse of syntenic breakpoints, and karyotype convergence in the context of a gene-based phylogeny.


Subject(s)
Centromere/classification , Centromere/genetics , Evolution, Molecular , Genome/genetics , Macropodidae/genetics , Animals , Base Sequence , Cytochromes b/genetics , DNA, Satellite/analysis , DNA, Satellite/genetics , Genetic Variation , In Situ Hybridization, Fluorescence , Karyotyping , Molecular Sequence Data , Phylogeny , Species Specificity , Translocation, Genetic
17.
Proc Natl Acad Sci U S A ; 104(30): 12404-9, 2007 Jul 24.
Article in English | MEDLINE | ID: mdl-17636118

ABSTRACT

Despite abundant examples of both adaptation at the level of phenotype and Darwinian selection at the level of genes, correlations between these two processes are notoriously difficult to identify. Positive Darwinian selection on genes is most easily discerned in cases of genetic conflict, when antagonistic evolutionary processes such as a Red Queen race drive the rate of nonsynonymous substitution above the neutral mutation rate. Genomic imprinting in mammals is thought to be the product of antagonistic evolution coincident with evolution of the placenta, but imprinted loci lack evidence of positive selection likely because of the ancient origin of viviparity in mammals. To determine whether genetic conflict is a general feature of adaptation to placental reproduction, we performed comparative evolutionary analyses of the insulin-like growth factor II (IGF2) gene in teleost fishes. Our analysis included several members of the order Cyprinodontiformes, in which livebearing and placentation have evolved several times independently. We found that IGF2 is subject to positive Darwinian selection coincident with the evolution of placentation in fishes, with particularly strong selection among lineages that have evolved placentation recently. Positive selection is also detected along ancient lineages of placental livebearing fishes, suggesting that selection on IGF2 function is ongoing in placental species. Our observations provide a rare example of natural selection acting in synchrony at the phenotypic and molecular level. These results also constitute the first direct evidence of parent-offspring conflict driving gene evolution.


Subject(s)
Evolution, Molecular , Fishes/genetics , Fishes/physiology , Insulin-Like Growth Factor II/genetics , Selection, Genetic , Amino Acid Sequence , Animals , Base Sequence , Conserved Sequence , Fishes/anatomy & histology , Insulin-Like Growth Factor II/chemistry , Molecular Sequence Data , Phylogeny , Sequence Alignment , Time Factors
18.
Eur Rev Med Pharmacol Sci ; 10(5): 223-8, 2006.
Article in English | MEDLINE | ID: mdl-17121314

ABSTRACT

The role of cytokines in systemic lupus erythematosus (SLE) glomerulonephritis is extremely complex. Proinflammatory molecules, such as TNF, IL-6, IL-1 and IL-18 are upregulated, as are both Thl and Th2 cytokines, with different implications: the local effects may be different from the systemic immunoregulatory ones. Excessive T helper cell function is a hallmark of SLE and abnormalities of Th citokine profiles have been implicated in loss of immune tolerance, increased antogenic load, defective B cell suppression and a variety of clinical manifestations. For some cytokines, TNF and IL-18 in particular, the local proinflammatory ones may be more relevant to the disease.


Subject(s)
Cytokines/biosynthesis , Kidney Diseases/economics , Kidney Diseases/metabolism , Lupus Erythematosus, Systemic/complications , Lupus Erythematosus, Systemic/metabolism , Humans
19.
Mycoses ; 49(5): 383-7, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16922789

ABSTRACT

Tinea incognito or steroid modified tinea is a dermatophytic infection in which topical or systemic steroids, administered as a result of dermatological misdiagnosis or preexisting pathologies, have modified the clinical appearance of the fungal infection, transforming the typical ringworm and mimicking other skin diseases. This is a retrospective study of the agents, clinical aspects, sources of infection of 200 cases (98 males, 102 females, mean age 42 years) of tinea incognito, observed in Siena and Milan, Italy, in the period 1987-2002. In order of decreasing frequency, Trichophyton rubrum, Trichophyton mentagrophytes, Epidermophyton floccosum, Microsporum canis, Microsporum gypseum, Trichophyton violaceum and Trichophyton erinacei were isolated. The clinical appearance of the infection was lupus erythematosus discoid-like, eczema-like, rosacea-like, especially on the face, impetigo-like and eczema-like on trunk and limbs. Less often the dermatophytosis resembled psoriasis, purpura, seborrhoic dermatitis and lichen planus. There was folliculitis in 9% of cases and dermatophytid in 3% of cases. Antimycotic therapy brought about clinical and mycological recovery in all patients except one, who had iatrogenic immunodepression.


Subject(s)
Tinea/diagnosis , Administration, Topical , Adult , Antifungal Agents/therapeutic use , Diagnosis, Differential , Epidermophyton/isolation & purification , Female , Humans , Italy , Male , Microsporum/isolation & purification , Mitosporic Fungi/classification , Mitosporic Fungi/isolation & purification , Retrospective Studies , Skin Diseases/diagnosis , Steroids/administration & dosage , Steroids/adverse effects , Tinea/drug therapy , Tinea/microbiology , Trichophyton/isolation & purification
20.
Genetics ; 172(2): 1129-37, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16387881

ABSTRACT

The constitution of the centromeric portions of the sex chromosomes of the red-necked wallaby, Macropus rufogriseus (family Macropodidae, subfamily Macropodinae), was investigated to develop an overview of the sequence composition of centromeres in a marsupial genome that harbors large amounts of centric and pericentric heterochromatin. The large, C-band-positive centromeric region of the X chromosome was microdissected and the isolated DNA was microcloned. Further sequence and cytogenetic analyses of three representative clones show that all chromosomes in this species carry a 178-bp satellite sequence containing a CENP-B DNA binding domain (CENP-B box) shown herein to selectively bind marsupial CENP-B protein. Two other repeats isolated in this study localize specifically to the sex chromosomes yet differ in copy number and intrachromosomal distribution. Immunocytohistochemistry assays with anti-CENP-E, anti-CREST, anti-CENP-B, and anti-trimethyl-H3K9 antibodies defined a restricted point localization of the outer kinetochore at the functional centromere within an enlarged pericentric and heterochromatic region. The distribution of these repeated sequences within the karyotype of this species, coupled with the apparent high copy number of these sequences, indicates a capacity for retention of large amounts of centromere-associated DNA in the genome of M. rufogriseus.


Subject(s)
Centromere/genetics , DNA/genetics , Macropodidae/genetics , X Chromosome/genetics , Animals , Base Sequence , DNA, Satellite/genetics , In Situ Hybridization, Fluorescence , Molecular Sequence Data
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