Peculiar CADASIL phenotype in monozygotic twins carrying a novel NOTCH3 pathogenetic variant

BACKGROUND

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominantly inherited cerebral small vessel disease caused by Neurogenic locus notch homolog protein 3 (NOTCH3) gene mutations. The main clinical features include migraine with aura, recurrent ischemic strokes and dementia. Brain MRI typically shows multiple small lacunar infarcts and severe, diffuse, symmetrical white matter hyperintensities (WMHs), with characteristic involvement of the anterior temporal pole, external capsule, and superior frontal gyrus. Reports of twins with CADASIL are scarce. Herein we describe a pair of monozygotic twins with peculiar CADASIL phenotype, carrying a new NOTCH3 variant.

CASE PRESENTATION

Twin A was a 45-year-old male suffering from migraine, obesity, arterial hypertension, and polycythemia (with negative genetic analysis), who complained of a transient, short-lasting (~ 5 minutes) episode of speech difficulties. Brain MRI showed diffuse, symmetrical, confluent periventricular WMHs involving frontal, parietal, and temporal lobes and external capsules, with sparing of anterior temporal poles. Genetic analysis of NOTCH3 gene demonstrated the presence of missense c.3329G>A, p.(Cys1110Tyr) variant, confirming CADASIL diagnosis. Twin B, affected by migraine and polycythemia, as well as his monozygotic twin, presented with a 2-month history of trigeminal neuralgia. Brain MRI demonstrated diffuse WMHs with a pattern of distribution like his twin. Genetic analysis revealed the same NOTCH3 pathogenic variant.

CONCLUSIONS

Our monozygotic twins have a strikingly similar neuroimaging picture with sparing of anterior temporal poles. They also have a peculiar phenotype, both presenting polycythemia without genetically confirmed cause. Twin B had trigeminal neuralgia, that is unusual in CADASIL. The possible association of the peculiar findings with the newly reported NOTCH3 variant needs to be confirmed with further observations.

Redox processes in Cu-binding proteins: the "in-between" states in intrinsically disordered peptides

We report on a concept that some of us first described a decade ago for pure electron transfer [V. Balland, C. Hureau and J.-M. Savéant, Proc. Natl. Acad. Sci. U. S. A., 2010, 107, 17113]. In the present viewpoint, based on more recent results, we refine and extend this "in-between state" concept to explain the formation of reactive oxygen species by copper ions bound to the amyloid-β (Aβ) peptide involved in Alzheimer's disease. In such intrinsically disordered peptides, the Cu coordination is versatile due to the lack of stable folding and the presence of multiple possible binding anchors. Hence, the Cu(I) and Cu(II) ions do impose their favoured sites, with Cu(I) bound in a linear fashion between two His residues and Cu(II) in a square-based pyramid bound to Asp1 amine and carbonyl groups and two His residues in the equatorial plane. Hence a direct electron transfer is prevented and alternatively an in-between state (IBS) mechanism applies, whose description and analysis with respect to other electron transfer processes is the topic of the present viewpoint.

Human serum albumin as a copper source for anticancer thiosemicarbazones

Thiosemicarbazones (TSCs) are a class of biologically active compounds with promising anticancer activity. Their typical mechanism, especially of the clinically far developed representative Triapine, is chelation of iron (Fe), with the Fe-containing enzyme ribonucleotide reductase as primary intracellular target. However, for the subclass of terminally disubstituted, nanomolar-active derivatives like Dp44mT and Me2NNMe2, recent findings suggest that the chelation, stability, and reduction properties of the copper(II) (Cu) complexes are essential for their modes of action. Consequently, it is important to elucidate whether blood serum Cu(II) is a potential metal source for these TSCs. To gain more insights, the interaction of Triapine, Dp44mT or Me2NNMe2 with purified human serum albumin (HSA) as the main pool of labile Cu(II) was investigated by UV-vis and electron paramagnetic resonance measurements. Subsequently, a size-exclusion chromatography inductively coupled plasma mass spectrometry method for the differentiation of Cu species in serum was developed, especially separating the non-labile Cu enzyme ceruloplasmin from HSA. The results indicate that the TSCs specifically chelate copper from the N-terminal Cu-binding site of HSA. Furthermore, the Cu(II)-TSC complexes were shown to form ternary HSA conjugates, most likely via histidine. Noteworthy, Fe-chelation from transferrin was not overserved, even not for Triapine. In summary, the labile Cu pool of HSA is a potential source for Cu-TSC complex formation and, consequently, distinctly influences the anticancer activity and pharmacological behavior of TSCs.

Revisiting the pro-oxidant activity of copper: interplay of ascorbate, cysteine and glutathione

Copper (Cu) is essential for most organisms, but it can be poisonous in excess, through mechanisms such as protein aggregation, trans-metallation and oxidative stress. Latter could implicate the formation of potentially harmful Reactive Oxygen Species (ROS: O2•-, H2O2 and HO•) via the redox cycling between Cu(II)/Cu(I) states in the presence of dioxygen and physiological reducing agents such as ascorbate (AscH), cysteine (Cys) and the tripeptide glutathione (GSH). Although the reactivity of Cu with these reductants has been previously investigated, the reactions taking place in a more physiologically-relevant mixture of these biomolecules are not known. Hence, we report here on the reactivity of Cu with binary and ternary mixtures of AscH, Cys and GSH. By measuring ascorbate and thiol oxidation, as well as HO• formation, we show that Cu reacts preferentially with GSH and Cys, halting AscH oxidation and also HO• release. This could be explained by the formation of Cu-thiolate clusters with both GSH and, as we first demonstrate here, Cys. Moreover, we observed a remarkable acceleration of Cu-catalysed GSH oxidation in the presence of Cys. We provide evidence that both thiol-disulfide exchange and the generated H2O2 contribute to this effect. Based on these findings, we speculate that Cu-induced oxidative stress may be mainly driven by GSH depletion and/or protein disulfide formation rather than by HO• and envision a synergistic effect of Cys on Cu toxicity.

Dual Role of Glutathione as a Reducing Agent and Cu-Ligand Governs the ROS Production by Anticancer Cu-Thiosemicarbazone Complexes

α-Pyridyl thiosemicarbazones (TSC) such as Triapine (3AP) and Dp44mT are a promising class of anticancer agents. Contrary to Triapine, Dp44mT showed a pronounced synergism with Cu^II, which may be due to the generation of reactive oxygen species (ROS) by Dp44mT-bound Cu^II ions. However, in the intracellular environment, Cu^II complexes have to cope with glutathione (GSH), a relevant Cu^II reductant and Cu^I-chelator. Here, aiming at rationalizing the different biological activity of Triapine and Dp44mT, we first evaluated the ROS production by their Cu^II-complexes in the presence of GSH, showing that Cu^II-Dp44mT is a better catalyst than Cu^II-3AP. Furthermore, we performed density functional theory (DFT) calculations, which suggest that a different hard/soft character of the complexes could account for their different reactivity with GSH.

Chasing the Elusive "In-Between" State of the Copper-Amyloidβ Complex by X-ray Absorption through Partial Thermal Relaxation after Photoreduction

The redox activity of Cu ions bound to the amyloid-β (Aβ) peptide is implicated as a source of oxidative stress in the context of Alzheimer's disease. In order to explain the efficient redox cycling between Cu(II)-Aβ (distorted square pyramidal) and Cu(I)-Aβ (digonal) resting states, the existence of a low-populated "in-between" state, prone to bind Cu in both oxidation states, has been postulated. Here, we exploited the partial X-ray induced photoreduction at 10 K, followed by a thermal relaxation at 200 K, to trap and characterize by X-ray Absorption Spectroscopy (XAS) a partially reduced Cu-Aβ1-16 species different from the resting states. Remarkably, the XAS spectrum is well-fitted by a previously proposed model of the "in-between" state, hence providing the first direct spectroscopic characterization of this intermediate state. The present approach could be used to explore and identify the catalytic intermediates of other relevant metal complexes.

Thermodynamics-based rules of thumb to evaluate the interaction of chelators and kinetically-labile metal ions in blood serum and plasma

Metal ions play a very important role in nature and their homeostasis is crucial. A lot of metal-related chemical research activities are ongoing that concern metal-based drugs or tools, such as chelation therapy, metal- and metabolite sensors, metallo-drugs and prodrugs, PET and MRI imaging agents, etc. In most of these cases, the applied chelator/ligand (L) or metal-ligand complex (M-L) has at least to pass the blood plasma to reach the target. Hence it is exposed to several metal-binding proteins (mainly serum albumin and transferrin) and to all essential metal ions (zinc, copper, iron, etc.). This holds also for studies in cultured cells when fetal calf serum is used in the medium. There is a risk that the applied compound (L or M-L) in the serum is transformed into a different entity, due to trans-metallation and/or ligand exchange reactions. This depends on the thermodynamics and kinetics. For kinetically-labile complexes, the complex stability with all the ligands and all metal ions present in serum is decisive in evaluating the thermodynamic driving force towards a certain fate of the chelator or metal-ligand complex. To consider that, an integrative view is needed on the stability constants, by taking into account all the metal ions present and all the main proteins to which they are bound, as well as the non-occupied metal binding site in proteins. Only then, a realistic estimation of the complex stability, and hence its potential fate, can be done. This perspective aims to provide a simple approach to estimate the thermodynamic stability of labile metal-ligand complexes in a blood plasma/serum environment. It gives a guideline to obtain an estimation of the plasma and serum complex stability and metal selectivity starting from the chemical stability constants of metal-ligand complexes. Although of high importance, it does not focus on the more complex kinetic aspects of metal-transfer reactions. The perspective should help for a better design of such compounds, to perform test tube assays which are relevant to the conditions in the plasma/serum and to be aware of the importance of ternary complexes, kinetics and competition experiments.

Copper-Catalyzed Glutathione Oxidation is Accelerated by the Anticancer Thiosemicarbazone Dp44mT and Further Boosted at Lower pH

Glutathione (GSH) is the most abundant thiol in mammalian cells and plays a crucial role in maintaining redox cellular homeostasis. The thiols of two GSH molecules can be oxidized to the disulfide GSSG. The cytosolic GSH/GSSG ratio is very high (>100), and its reduction can lead to apoptosis or necrosis, which are of interest in cancer research. Cu^II ions are very efficient oxidants of thiols, but with an excess of GSH, Cu^I_n(GS)_m clusters are formed, in which Cu^I is very slowly reoxidized by O₂ at pH 7.4 and even more slowly at lower pH. Here, the aerobic oxidation of GSH by Cu^II was investigated at different pH values in the presence of the anticancer thiosemicarbazone Dp44mT, which accumulates in lysosomes and induces lysosomal membrane permeabilization in a Cu-dependent manner. The results showed that Cu^II-Dp44mT catalyzes GSH oxidation faster than Cu^II alone at pH 7.4 and hence accelerates the production of very reactive hydroxyl radicals. Moreover, GSH oxidation and hydroxyl radical production by Cu^II-Dp44mT were accelerated at the acidic pH found in lysosomes. To decipher this unusually faster thiol oxidation at lower pH, density functional theory (DFT) calculations, electrochemical and spectroscopic studies were performed. The results suggest that the acceleration is due to the protonation of Cu^II-Dp44mT on the hydrazinic nitrogen, which favors the rate-limiting reduction step without subsequent dissociation of the Cu^I intermediate. Furthermore, preliminary biological studies in cell culture using the proton pump inhibitor bafilomycin A1 indicated that the lysosomal pH plays a role in the activity of Cu^II-Dp44mT.

A luminescent ATCUN peptide variant with enhanced properties for copper(II) sensing in biological media

The measurement of labile Cu^II in biological samples is fundamental for understanding Cu metabolism and has been emerging as a promising diagnostic marker for Cu-related pathologies such as Wilson's and Alzheimer's diseases. The use of fluorescent chelators may be useful to circumvent separation steps employed by current methods. For this purpose, we recently designed a selective and suited-affinity turn-off luminescent probe based on a peptide bearing the Cu^II-binding Xxx-Zzz-His (Amino-Terminal Cu^II- and Ni^II-binding, ATCUN) motif and a Tb^III-DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) complex. Here, we present an analogue probe bearing the ATCUN motif variant Xxx-His-His. This probe showed much faster response in biologically-relevant media and higher stability than the previous motif at low pH. These features could be beneficial to the measurement of dynamic Cu^II fluctuations and the application in slightly acidic media, such as urine.

A terbium(iii) luminescent ATCUN-based peptide sensor for selective and reversible detection of copper(ii) in biological media

Detection of copper(ii) in biological media via time-delayed luminescence by a selective and reversible terbium(iii)-luminescent peptide sensor with pM affinity.

Reversible turn-on fluorescent Cu(ii) sensors: rather dream than reality?

Reversible turn-on fluorescent Cu(ii) sensors are of high interest to understand copper metabolism in biology and medicine. However, they are intrinsically difficult to build, and careful studies are needed to exclude Cu(ii)-induced sensor oxidation.

Mutant p53 inhibits miRNA biogenesis by interfering with the microprocessor complex

Downregulation of microRNAs (miRNAs) is commonly observed in cancers and promotes tumorigenesis suggesting that miRNAs may function as tumor suppressors. However, the mechanism through which miRNAs are regulated in cancer, and the connection between oncogenes and miRNA biogenesis remain poorly understood. The TP53 tumor-suppressor gene is mutated in half of human cancers resulting in an oncogene with gain-of-function activities. Here we demonstrate that mutant p53 (mutp53) oncoproteins modulate the biogenesis of a subset of miRNAs in cancer cells inhibiting their post-transcriptional maturation. Interestingly, among these miRNAs several are also downregulated in human tumors. By confocal, co-immunoprecipitation and RNA-chromatin immunoprecipitation experiments, we show that endogenous mutp53 binds and sequesters RNA helicases p72/82 from the microprocessor complex, interfering with Drosha-pri-miRNAs association. In agreement with this, the overexpression of p72 leads to an increase of mature miRNAs levels. Moreover, functional experiments demonstrate the oncosuppressive role of mutp53-dependent miRNAs (miR-517a, -519a, -218, -105). Our study highlights a previously undescribed mechanism by which mutp53 interferes with Drosha-p72/82 association leading, at least in part, to miRNA deregulation observed in cancer.

Pandemic influenza A/H1N1 virus in a swine farm house in Sicily, Italy

This report describes a pandemic A/H1N1 (H1N1 pdm) virus outbreak occurred in December, 2009 in a swine farm used as research facility (Istituto Mediterraneo Trapianti e Terapie ad Alta Specializzazione) for preclinical studies, located in Sicily, Italy. All the 13 pigs of the farm, showed cough, fever, inappetence and weakness. At the same time, an unvaccinated worker of the stabling showed influenza-like symptoms. RNAv extracted from two swabs collected from infected pigs resulted positive by Real Time RT-PCR for Influenza A virus. Furthermore, after growth on embryonated eggs, viral isolates were identified by Real Time RT-PCR specific for H1N1 pdm virus and characterized antigenically. Sequencing of the whole genome was also performed. All sera taken from animals and from the worker were tested by a competitive influenza A ELISA and by the haemoagglutination inhibition test. Serological findings confirmed the circulation of influenza virus H1N1 pdm in pigs and the presence of specific antibodies against H1N1 pdm in human serum. The results of this study seem to support a H1N1 pdm transmission from man to animals showing the importance of serological and virological investigation to control the pig farms and the importance of close cooperation between the different authorities like veterinarian and human public.

Molecular characterization of bovine rotavirus strains circulating in northern Italy, 2003-2005

A total of 232 stools collected from calves with rotavirus infection in herds located in northern Italy from 2003 to 2005 was investigated. Determination of the rotavirus G and P types was carried out using nested RT-PCR. G6 was the most prevalent genotype, accounting for 78.5% of samples, G10 accounted for 9.9% of samples and viruses of G8 type were found in 4.7% of samples. In 3% of samples, viruses were not classified due to concomitant infection with more G type strains, whereas viruses in 3.9% of samples could not be characterized with any of the G-specific primers used in this study. Most common P types were P[11] and P[5], accounting for 65.1% and 25%, respectively. In 2.6% of cases, samples reacted with multiple P-specific primers; no P[1] serotype was identified. The G6P[11] combination was predominant throughout the study period, i.e. 52.5% in 2003, 50% in 2004 and 40% in 2005. The incidence of G6P[5] increased from 13.1% in 2003 to 27% in 2004 and 25.5% in 2005. The G10P[11] combination decreased markedly from 18% in 2003 to 2.6% in 2004, rising again to 7.3% in 2005. G8P[11] viruses were similarly present in 2003 (5%) and 2004 (4.3%), declining slightly in 2005 (1.8%).

[Idiopathic and secondary osteoporosis in childhood]

Osteoporosis is a common disease characterized by reduced bone mass, with a consequent increase in bone fragility and susceptibility to fracture risk. Bone mineral density (BMD) measurement is used to make the diagnosis of osteoporosis prior to incident fracture, and to predict fracture risk. BMD is determined by the peak bone mass achieved, and the rate and timing of subsequent bone loss. Dual-energy X-ray absorptiometry (DEXA) is the most popular and effective method utilized for osteoporosis screening. Bone disease is a side effect of concern regarding chronic glucocorticoid (GC) administration. Most GC-treated patients exhibit a process of bone loss, frequently leading to osteoporosis, with increased fracture risk, especially in spinal vertebrae. Osteogenesis imperfecta is an inherited and generalized connective tissue disorder characterized mainly by bone fragility. Idiopathic osteoporosis of childhood or adolescence without blue sclerae and other stigmata of osteogenesis imperfecta is occasionally observed and sometimes more than one sib is affected. Beta-thalassemia major is associated with significant bone disease. The etiology of the bone disease is still debatable, many factors can adversely affect bone accretion in thalassemic patients. These include delayed puberty, bone marrow expansion, the deleterious effects of desferrioxamine, iron overload and genetic factors. Current treatment alternatives of osteoporosis include bisphosphonates, calcitonin, and selective estrogen receptor modulators.

Sequence analysis of the VP7 and VP4 genes identifies a novel VP7 gene allele of porcine rotaviruses, sharing a common evolutionary origin with human G2 rotaviruses

During an epidemiological survey encompassing several porcine herds in Saragoza, Spain, the VP7 and VP4 of a rotavirus-positive sample, 34461-4, could not be predicted by using multiple sets of G- and P-type-specific primers. Sequence analysis of the VP7 gene revealed a low amino acid (aa) identity with those of well-established G serotypes, ranging between 58.33% and 88.88%, with the highest identity being to human G2 rotaviruses. Analysis of the VP4 gene revealed a P[23] VP4 specificity, as its VP8* aa sequence was 95.9% identical to that of the P14[23],G5 porcine strain A34, while analysis of the VP6 indicated a genogroup I, that is predictive of subgroup I specificity. Analysis of the 10th and 11th RNA segments revealed close identity to strains of porcine and human origin, respectively. The relatively low overall aa sequence conservation (<89% aa) to G2 human rotaviruses, the lack of N-glycosylation sites that are usually highly conserved in G2 rotaviruses, and the presence of several amino acid substitutions in the major antigenic hypervariable regions hampered an unambiguous classification of the porcine strain 34461-4 as G2 serotype on the basis of sequence analysis alone. The identification of a borderline, G2-like, VP7 gene allele in pigs, while reinforcing the hypotheses of a tight relationship in the evolution of human and animal rotaviruses, provides additional evidence for the wide genetic/antigenic diversity of group A rotaviruses.

[Inherited disorders of bilirubin metabolism]

Jaundice in an infant or older child may reflect accumulation of either unconjugated or conjugated bilirubin and could be related to inherited bilirubin disorders. Three grades of inherited unconjugated hyperbilirubinemia are recognised in humans. This spectrum of disorders is distinguished primarily on the basis of the plasma bilirubin level, the response to phenobarbital administration, and the presence or absence of bilirubin glucoronides in bile. The enzyme responsible for the conjugation of bilirubin is the bilirubin uridine-diphosphate-glucuronosyltransferase (UGT). Mutations in the gene encoding bilirubin-UGT (UGT1A1), lead to complete or partial inactivation of the enzyme causing the rare autosomal recessively inherited conditions, Crigler-Najjar syndrome type 1 (CN-1) and type 2 (CN-2). Gilbert syndrome (GS) is due to an insertional mutation at homozygous state of the TATAA element (seven TA repeats) of UGT1A1 producing a reduced level of expression of the gene. The association of GS with haemolytic anemias, e.g., Hereditary Spherocytosis (HS) or Congenital Dyserythropoietic Anemia type 2 (CDA 2), increase the hyperbilirubinemia level and the risk of cholelithiasis. Forms of chronic conjugated hyperbilirubinemia are Dubin-Johnson syndrome, Rotor syndrome, Alagille syndrome or arteriohepatic dysplasia, Wilson disease or hepatolenticular degeneration. Liver or liver cell transplantation is the therapy in some cases.

Experimental infection of calves with bovine viral diarrhoea virus type-2 (BVDV-2) isolated from a contaminated vaccine

A non-cytopathic strain of BVDV-2 was isolated from a batch of live infectious bovine rhinotracheitis (IBR) vaccine, and inoculated intranasally into four 3-month-old calves. Severe signs of disease developed by days 4 and 6 in three of the calves, free of BVDV and antibodies to BVDV, that had been exposed to the virus. These calves survived the acute phase of the infection and progressively recovered. BVDV was consistently isolated, or the respective viral RNA was detected, in the buffy coats from blood samples collected starting from days 2 or 4 up to days 11 or 14 after the experimental infection. Viral RNA was also detected in sera from these infected calves until the presence in the serum of virus neutralizing antibodies was demonstrated. By contrast, the only calf having pre-existing neutralizing antibodies to BVDV at the start of the study was protected from the disease. No virus was detected at any time after experimental inoculation of this calf. Genomic characterization of the BVDV-2 isolated in cell cultures, or detected in sera from the experimentally infected animals, revealed 100%, homology in the nucleotide sequence with the BVDV-2 detected as a contaminant of the live IBR virus vaccine. These findings provided evidence of the infective nature of the contaminant BVDV-2 and of its potential to generate disease outbreaks when inoculated into susceptible animals.

Genetic heterogeneity of bovine viral diarrhoea virus in Italy

The genetic characteristics, of 38 field isolates of bovine viral diarrhoea virus (BVDV) collected in 1999 from sick or healthy and persistently infected cattle of dairy farms situated in northern Italy, were investigated. A partial 5'-untranslated region (5'-UTR) sequence of each isolate was determined and a phylogenetic analysis was performed. All the isolates were classified as belonging to the BVDV-1 genotype and could be assigned to different BVDV-1 groups, namely BVDV-1b (n = 20), BVDV-1d (n = 6) and BVDV-1e (n = 10). Two remaining isolates could be classified as BVDV-1f and BVDV-1h, respectively. These results provided evidence for genetic heterogeneity of BVDV in Italy, and contribute to a better knowledge of the circulation of BVDV strains, and to their classification.

Standardization of an Inactivated H7N1 Avian Influenza Vaccine and Efficacy Against A/Chicken/Italy/13474/99 High-Pathogenicity Virus Infection

The minimum requirements for assessing the immunogenicity of an experimental avian influenza (AI) vaccine prepared from inactivated A/Turkey/Italy/2676/99 (H7N1) low-pathogenicity (LP) AI (LPAI) virus were determined in chickens of different ages. A correlation between the amount of hemagglutinin (HA) per dose of vaccine and the protection against clinical signs of disease and infection by A/Chicken/Italy/13474/99 highly pathogenic (HP) AI (HPAI) virus was established. Depending on the vaccination schedule, one or two administrations of 0.5 microg of hemagglutinin protected chickens against clinical signs and death and completely prevented virus shedding from birds challenged at different times after vaccination.

Genotyping of bovine viral diarrhoea viruses isolated from cattle in northern Italy

Following the first official report of a clinically severe outbreak of bovine viral diarrhoea disease occurring in a farm in northern Italy, which had originated from the use of a live vaccine contaminated with a strain of BVD genotype II virus, a retrospective study on the prevalence of BVDV genotypes in Italy became highly relevant. For this purpose, the genotype of 78 BVDV-positive specimens, obtained in 1998-1999 from dairy cattle in an area near to where the outbreak occurred, was characterized by PCR technology. Two sets of primers, spanning the 5' UTR of BVDV genome, were used sequentially in a first round of RT-PCR, performed on viral RNA extracted directly from 15 clinical samples and 63 BVDV-infected cell-culture fluids; a second PCR assay followed to selectively amplify only BVDV genotype II. All the viruses under study were characterized as BVDV genotype I. As well as contributing to a better understanding of the prevalence of BVDV genotypes in the field, the results of the present study illustrate the possibility that novel BVDV strains can emerge in susceptible animals through the use of contaminated immunobiological products for bovine use.

Determination of bovine rotavirus G and P serotypes in italy by PCR

Determination of the G and P serotypes of group A bovine rotaviruses from 149 samples of feces or intestinal contents collected from calves showing clinical signs of neonatal diarrhea was performed by a nested reverse transcription-PCR typing assay. The G6 serotype was the most prevalent, accounting for viruses in 55.7% of the samples; viruses of the G10 and G8 serotypes were found in 34.9 and 4.7% of the samples, respectively. The virus in one sample (0.7%) was not classified due to concomitant infection with G6 and G8 strains, whereas viruses in six samples (4.0%) could not be characterized with any of the three G serotype-specific primers selected for the present study. When examined for their P-serotype specificities, viruses in 55 and 42.3% of the samples were characterized as P[11] and P[5], respectively, no P[1] serotype was identified, and viruses in 2.7% of the samples could not be classified due to multiple reactivity with both P[5]- and P[11]-specific primers. Various combinations of G and P serotypes were observed, the most frequent being G6,P[5] (38.3%), G10,P[11] (31.5%), and G6,P[11] (15.4%). The results of the present study, while contributing to a better understanding of the epidemiology of bovine rotaviruses in Italy, address the relevance of serotype specificity with regard to the constancy of the quality of bovine rotavirus vaccines under different field conditions.

Mitochondrial DNA inherited variants are associated with successful aging and longevity in humans

Mitochondrial DNA (mtDNA) is characterized by high variability, maternal inheritance, and absence of recombination. Studies of human populations have revealed ancestral associated polymorphisms whose combination defines groups of mtDNA types (haplogroups) that are currently used to reconstruct human evolution lineages. We used such inherited mtDNA markers to compare mtDNA population pools between a sample of individuals selected for successful aging and longevity (212 subjects older than 100 years and in good clinical condition) and a sample of 275 younger individuals (median age 38 years) carefully matched as to sex and geographic origin (northern and southern Italy). All nine haplogroups that are typical of Europeans were found in both samples, but male centenarians emerged in northern Italy as a particular sample: 1) mtDNA haplogroup frequency distribution was different between centenarians and younger individuals (P=0.017 by permutation tests); and 2) the frequency of the J haplogroup was notably higher in centenarians than in younger individuals (P=0.0052 by Fisher exact test). Since haplogroups are defined on the basis of inherited variants, these data show that mtDNA inherited variability could play a role in successful aging and longevity.

Gene/longevity association studies at four autosomal loci (REN, THO, PARP, SOD2)

The possibility that four loci (REN, THO, PARP, SOD2) are associated with longevity was explored by comparing the genotypic pools of subjects older than 100 years with those of younger subjects matched for sex and geographic area (northern and southern Italy). The markers (all located within the respective gene) were HUMREN4; HUMTHO1; HUMPARP (gt)845nt; SOD2(C/T)401nt. In order to reduce the number of genotypes, multiallelic polymorphisms were recoded as diallelic according to allele size and frequency patterns (small: S, and large: L, alleles). A significant loss of LL homozygous genotypes was found at the THO locus in male but not in female centenarians with respect to matched controls. On the other hand no significant difference was found between case/control genotypic frequencies at REN, PARP, SOD2 loci. The latter loci therefore do not affect inter-individual variability in life expectancy (at least in terms of qualitative variants associated with the tested markers). However, the data is consistent with an association between the THO locus and longevity.

Comparative evaluation of in vitro and in vivo assays for the detection of avian infectious bronchitis virus as a contaminant of live poultry vaccines

A reverse transcriptase polymerase chain reaction (RT-PCR( assay specific for identifying avian infectious bronchitis virus (IBV) in poultry vaccines, and the serological response to IBV induced by the inoculation of chicks with a Newcastle disease vaccine spiked with the Massachusetts strain of IBV, were compared for their ability to detect IBV as a contaminant of avian vaccines. The sensitivity of the IBV-RT-PCR assay provided results which were at least equivalent to the biological effect produced by the inoculation of chicks, allowing this assay to be considered a valid alternative to animal testing in the quality control of avian immunologicals. This procedure can easily be adapted to detect a number of contaminants for which the in vivo test still represents the only available method of detection.

Age-related changes of the 3'APOB-VNTR genotype pool in ageing cohorts

The analysis of seven different age cohorts (697 individuals from 10 to 109 years old) revealed age-related changes in the 3'APOB-VNTR genotype pool. By recoding the 3'APOB-VNTR alleles into three size-classes (small, S, 26-34 repeats; medium, M, 35-39 repeats; large, L, 41-55 repeats), an age-related convex trajectory of the frequency of SS homozygotes was found. The frequency of SS in the genotype pool increased from the group aged 10-19 years (3.06 +/- 1.74%) to that aged 40-49 years (8.51 +/- 4.07%). Then it declined reaching the minimum value in centenarians (1.58 +/- 0.90%). The observed trajectory is in agreement with that expected by assuming crossing of mortality curves relevant to subgroups of individuals having different genotypes.

DNA multiallelic systems reveal gene/longevity associations not detected by diallelic systems. The APOB locus

To identify possible genetic factors affecting human longevity we compared allele pools at two candidate loci for longevity between a sample of 143 centenarians (S) and a control sample of 158 individuals (C). The candidate loci were APOB and TPO, which code for apolipoprotein B and thyroid peroxidase, respectively. Both restriction fragment length (RFL) (XbaI2488 and EcoRI4154) and variable number of tandem repeat (VNTR) (3'APOB-VNTR) polymorphisms were analysed at the APOB locus; the TPO-VNTR polymorphism (intron 10) was analysed at the TPO locus. The main result of the investigation was that there is an association between the APOB locus and longevity that is revealed only when multiallelic polymorphisms are considered. In particular: (i) the frequency of 3'APOB-VNTR alleles with fewer than 35 repeats is significantly lower in cases than in controls; (ii) the linkage disequilibrium between the XbaI-RFLP and the EcoRI-RFLP is significantly different from 0 in cases but not in controls; (iii) the EcoRI-RFLP and XbaI-RFLP allele frequencies do not discriminate between cases and controls. The differences observed between case and control allele pools are specific to the APOB locus, since no significant difference was observed at the TPO locus.

Rapid diagnosis of avian infectious bronchitis virus by the polymerase chain reaction

A simple, sensitive and specific polymerase chain reaction (PCR) procedure was developed in order to detect infectious bronchitis virus (IBV) directly in tissue samples. Viral RNA was extracted from allantoic fluids and cell cultures infected experimentally with different strains of IBV and from tissues of naturally infected birds. Viral RNA was then amplified and identified by a nested RT-PCR assay using two sets of primers flanking a well-conserved region of the nucleocapsid gene. The selected IBV nucleocapsid sequence was detected successfully by simple direct electrophoresis of amplified material.

Allele frequency distributions at seven DNA hypervariable loci in a population sample from Calabria (southern Italy)

Genotype and allele frequencies at seven Variable Number of Tandem Repeats (VNTR) loci currently used for forensic purposes have been estimated in a population sample from Calabria (south Italy). DNA target regions relevant to four microsatellites (THO.1; REN.4; D12S67; DYS19) and three minisatellites (D1S80; 3'APOB; TPO.10) were amplified by Polymerase Chain Reaction (PCR) and analysed by electrophoresis and ethidium bromide or silver staining. For all loci, the observed genotypes were found to be in agreement with those expected by the Hardy-Weinberg equilibrium. Data on allele frequencies were in line with those found in sample groups from northern or central Italy, tested for some of the above polymorphisms.

Linkage disequilibrium studies in the thyroid peroxidase and apolipoprotein B genes

Linkage disequilibria in the apolipoprotein B (APOB) gene (EcoRI RFLP/3' APOB VNTR) and in the thyroid peroxidase (TPO) gene (AcyI RFLP/TPO VNTR) were investigated in a sample of 100 individuals from southern Italy. By recoding multiallelic data as diallelic data, each RFLP-VNTR system showed linkage disequilibrium significantly different from zero (EcoRI RFLP/3' APOB VNTR: p < 0.001; AcyI RFLP/TPO VNTR: p < 0.025), thus suggesting that the VNTR arrays are stable. Furthermore, the relationship between the 3' APOB (2p24-p23) and TPO (2pter-p24) VNTR multiallelic systems was also analyzed. The two VNTR polymorphisms were found to be in linkage equilibrium, thus indicating that they can be used together in forensic casework.

DYS19, D12S67, and D1S80 polymorphisms in population samples from southern Italy and Greece

Genotype and allele frequencies of the DYS19, D12S67, and D1S80 highly polymorphic loci were determined in population samples from southern Italy (103 subjects) and Greece (84 subjects) using the amplified fragment length polymorphism (AFLP) technique (polymerase chain reaction followed by native PAGE and silver staining). Five, eleven, and eighteen alleles were found at the DYS19, D12S67, and D1S80 loci, respectively. PIC values ranged from 0.55 (DYS19 locus in Italians) to 0.79 (D12S67 locus in Italians). The distribution of D12S67 and D1S80 genotypes conformed to Hardy-Weinberg equilibrium, as confirmed by three statistics. Heterogeneity G tests, carried out on allele frequency distributions, showed a significant difference between the samples at the DYS19 locus, whereas no difference was found with regard to the other polymorphisms. Using data from the literature, we widened the comparison to other European groups analyzed for the same markers. All the polymorphisms were found to distinguish between populations of the same main ethnic group. In particular, D1S80 allele frequencies distinguished the Finns from other European groups (Spanish, German, Italian, and Greek samples). The reduced assay time, the high polymorphism level, and the ability to distinguish between populations indicate that these markers have potential value in population genetic studies.

RFLPs of the APOB gene: comparative study between Greeks and southern Italian peoples

Restriction fragment length polymorphisms (RFLPs) at codons 2488 (XbaI), 3611 (MspI), and 4154 (EcoRI) of the apolipoprotein B gene were investigated in sample groups from Athens (Greece) and Calabria (southern Italy) to verify whether the distribution of the APOB gene variants in Calabria, where Greek colonization occurred in the eighth century B.C., reflects that of the present Greek population. A sample from Apulia, a southern Italian region having a history different from that of Calabria, was also analyzed. Three specific DNA regions, each containing the polymorphic site, were amplified by polymerase chain reaction on 243 samples, and the restriction data for the three groups were compared. The allelic frequencies of the samples from Apulia and Greece showed variability patterns that agree with those found in Caucasians, whereas the Calabrian sample shows remarkable peculiarities, mainly for the EcoRI RFLP. Linkage disequilibrium analyses of pairs of markers showed strong D linkage values between X-M markers, whereas the D linkage values between M-R markers were too small to be reliably estimated. Last, for both Apulians and Greeks, X-R markers showed linkage disequilibrium, whereas for Calabrians they did not. Estimates of XMR haplotypic frequencies were computed; they were found to be appreciably different between Calabrian and Greek samples, whereas the frequencies in the Apulian sample were approximately midway between those in Calabrians and Greeks.

A rapid serum neutralization test in microplates for the detection of antibodies to hog cholera virus

The fluorescent antibody serum neutralization (FASN) test for the detection of antibodies to hog cholera virus was developed utilizing 96-well and Terasaki microplates. This microtechnique, especially when performed in Terasaki plates, offers some advantage if compared with conventional FASN in coverslip cell cultures, being easier and more rapid, saving of reagents and allowing simple microscopic observation.

Susceptibility of a minipig kidney cell line (MPK) to hog cholera virus

A comparitive study on the different susceptibility of MPK cells (Minipig Kidney cell line) and PK15 cells (Pig Kidney cell line) to the Hog Cholera Virus (HCV) was conducted. Higher HCV titres (3 log10) were reached on MPK cells compared with PK15 cells.

Urinary and faecal mutagenicity in Sprague-Dawley rats dosed with the food mutagens quercetin and rutin

The natural flavonoid quercetin was administered to Sprague-Dawley rats by ip injection or gastric intubation of a single dose of 500, 1000 or 2000 mg/kg body weight. Mutagenicity assays with Salmonella typhimurium strain TA98 showed moderate mutagenic activity in the urines and faecal extracts but not in plasma samples from the treated animals. The mutagenic activity detected in the urines accounted for about 0.5% of the administered dose, irrespective of the route of administration and the dose level. Higher mutagenicity was demonstrated in faecal extracts. Rutin (quercetin-3-O-rutinoside) was administered by gavage and ip injection at 2000 mg/kg. Although the chemical was inactive as a mutagen in vitro, significant mutagenicity was detected in the urines and faecal extracts of the treated rats. Such activity was similar to that detected after administration of free quercetin in a dose some four times lower (by weight).

Monitoring of urinary mutagenicity in workers exposed to low doses of 2,4,7-trinitro-9-fluorenone

A monitoring of the urinary mutagenicity in workers occupationally exposed to low doses of 2,4,7-trinitro-9-fluorenone (TNF) was undertaken. Urine concentrate of 22 exposed workers (11 smokers and 11 nonsmokers) and 18 presumedly unexposed workers (7 smokers and 11 nonsmokers) were assayed for mutagenicity in Salmonella typhimurium strain TA98 with the plate incorporation technique. In this test system none of the urine concentrate was effective as a mutagen, either in the absence or presence of S9. Fifteen urine samples (8 from exposed workers, 7 from referents) were also tested in the microtiter fluctuation assay. With this technique smoking habits were significantly related to urinary mutagenicity in tests performed with metabolic activation. In neither case however was the association between presumed exposure and urinary mutagenicity significant. These results were evaluated on the basis of urinary mutagenicity data obtained from rats exposed to TNF by different routes. It was shown that the observed urinary mutagenicity accounts for a minor fraction of the administered TNF dose (about 0.1 to 0.2%, depending on the route of exposure); thus it is possible that low-level exposure to TNF could escape detection by urinary mutagenicity monitoring.

Mutagenicity studies in a tyre plant: in vitro activity of workers' urinary concentrates and raw materials

The possible contribution to urinary mutagenicity of occupational exposures in the rubber industry was studied by assaying the urine concentrates of 72 workmen (44 smokers) employed in a tyre plant. Twenty three clerks (16 smokers) engaged in the administrative department of the same factory served as presumptive unexposed controls. XAD-2 resin concentrates of urine samples were assayed in the plate incorporation test and in the microtitre fluctuation assay with Salmonella typhimurium strains TA1535, TA98, and TA100. Furthermore, the in vitro mutagenicity of the major raw materials in use at the plant was determined in the plate incorporation assay with S typhimurium strains TA1535, TA1537, TA98, and TA100. The results obtained from the urinary mutagenicity study show that smoking habits, but not occupation, were statistically significantly related to the appearance of a urinary mutagenicity that was detectable with strain TA98. A possible synergistic effect of occupation with smoking was observed among tyre builders who were also smokers. The study of the raw materials showed that three technical grade materials were weakly active as mutagens in strain TA98 in the absence (poly-p-dinitrosobenzene) or in the presence of metabolic activation (mixed diaryl-p-phenylendiamines and tetramethyltiuram disulphide). The latter chemical was also weakly active in strain TA100.

In vitro mutagenicity of rubber chemicals and their nitrosation products

14 chemicals employed in rubber manufacture were assayed in the Salmonella reversion test with the strains TA98 and TA100. Mixed diaryl-p-phenylenediamines were weakly mutagenic in TA98 after metabolic activation; poly-p-dinitrosobenzene was active in TA98 without as well as with S9. After in vitro reaction with nitrite at low pH, mixed diaryl-p-phenylenediamines became directly mutagenic in both strains, whereas poly-p-dinitrosobenzene retained its activity unchanged. Furthermore, 4 of the remaining chemicals acquired mutagenic characteristics: in the presence of S9, N,N'-dimethylpentyl-p-phenylenediamine reverted TA98 and hexamethylenetetramine reverted both TA98 and TA100; N-isopropyl-N'-phenyl-p-phenylenediamine was mutagenic in TA98 with and without S9; N-nitrosodiphenylamine was active in both strains without S9 and weakly mutagenic in TA98 after metabolic conversion.

DNA repair induction by cytostatic drugs in proliferating and quiescent MRC-5 cells

The repair of DNA damage is closely related to cell cycle, in terms of both modulation of repairing ability throughout the cell cycle and perturbations in replication. We have studied the induction of Unscheduled DNA Synthesis (UDS) in human fibroblasts (MRC-5) by some chemotherapeutic agents, selected for their different mechanisms of action. To take into account the interaction between repair and replication systems, the experiments were performed in both proliferating and quiescent cultures; semiconservative DNA synthesis inhibition was examined by microphotometric measurements in the same autoradiographic preparations used for UDS analysis. Vincristine, methotrexate and 6-thioguanine induced no UDS. Adriamycin, actinomycin D, and, to a lesser extent, cyclophosphamide and thiotepa gave positive results only in proliferating cultures, whereas bleomycin was an effective inducer of UDS in quiescent cells, with weak UDS levels in proliferating ones. In all these cases, the combined analysis of UDS and semiconservative DNA synthesis inhibition proved to be of value in the assessment of interaction between drugs and DNA in proliferating cultures. The results of our experiments emphasize the importance of the cycling conditions in the cellular response to DNA damage.

A study on the urinary and fecal excretion of furazolidone in rats by means of mutagenicity assays

The urinary and fecal excretion of furazolidone in rats was studied by means of mutagenicity assays: when animals received a single dose by gavage (1 to 10 mg/100 g body wt) the mutagenic activity recovered in urines accounted for less than 0.1% of the administered dose and quickly disappeared. After prolonged (1 week) treatments, however, some mutagenicity was retained in urine concentrates until the fifth to seventh days. Similarly the fecal excretion of mutagenicity accounted for less than 0.1% of the administered dose and disappeared within the third day. The efficient deactivation of furazolidone observed in vivo was shown to be unaffected by the amount of gut bacteria in treated animals; in in vitro experiments it turned out to be actively performed by a rat intestine homogenate fraction, working more efficiently under hypoxic conditions.