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Biomedical subjects

R Moroni

Publications and source records attributed to R Moroni.

At least 19 recordsLinked to original sources
PubMed2006

Isolating the step contribution to the uniaxial magnetic anisotropy in nanostructured Fe/Ag(001) films.

We have investigated the possibility of isolating the step-induced in-plane uniaxial magnetic anisotropy in Fe/Ag(001) films on which nanoscale surface ripples were fabricated by the ion sculpting technique. For rippled Fe films deposited on flat Ag(001), the steps created along the ripple sidewalls are shown to be the only source of uniaxial anisotropy. Ion sculpting of ultrathin magnetic films allows one to selectively study the step-induced anisotropy and to investigate the correlation between local atomic environment and magnetic properties.

Journal Article↗
PubMed2005

Evidence by expression analysis of candidate genes for congenital heart defects in the NF1 microdeletion interval.

It was recently reported that congenital heart disease is significantly more frequent in patients with NF1 microdeletion syndrome than in those with classical NF1. The outcome of congenital heart disease in this subset of patients is likely caused by the haploinsufficiency of gene/s in the deletion interval. Following in silico analysis of the deleted region, we found two genes known to be expressed in adult heart, the Joined to JAZF1 (SUZ12) and the Centaurin-alpha 2 (CENTA2) genes, and seven other genes with poorly defined patterns of expression and function. With the aim of defining their expression profiles in human fetal tissues (15th-21st weeks of gestation), expression analysis by RT-PCR and Northern blotting was performed. C17orf40, SUZ12 and CENTA2 were found to be mainly expressed in fetal heart, and following RT-PCR on mouse embryos and embryonic heart and brain at different stages of development, we found that the orthologous genes C17orf40, Suz12 and Centa2 are also expressed in early stages of development, before and during the formation of the four heart chambers. The presence of binding sites for Nkx2-5, a transcription factor expressed early in heart development, in all three mouse orthologous genes was predicted by bioinformatics, thus reinforcing the hypothesis that these genes might be involved in heart development and may be plausible candidates for congenital heart disease.

Animals↗
PubMed2003

Uniaxial magnetic anisotropy in nanostructured Co/Cu(001): from surface ripples to nanowires.

We have investigated the correlation between morphology and magnetic anisotropy in nanostructured Co films on Cu(001). The formation of nanoscale ripples by ion erosion is found to deeply affect the magnetic properties of the Co film. A surface-type uniaxial magnetic anisotropy with easy axis parallel to the ripples is observed. The origin of the magnetic anisotropy has been identified with the modification of thermodynamic-step distribution induced by ripple formation. At higher ion doses, when Co ripples detach and crystalline nanowires form, a strong enhancement of the magnetic anisotropy due to magnetostatic contributions is observed.

Journal Article↗
PubMed2000

Changes of mate occur in Schistosoma mansoni.

Male and female schistosomes are generally assumed to form stable monogamous pairs for the whole span of their long existence in the mammalian host. Recent evidence from mixed infections has shown that Schistosoma mansoni males can displace S. intercalatum males from their homologous partners, but no information exists about the existence of similar phenomena within a single schistosome species. Here, we determine whether male S. mansoni can displace males of the same species from pre-formed pairs in vivo. The availability of clear-cut genetic markers of drug resistance in schistosomes was exploited to show that hycanthone sensitive S. mansoni males can displace homospecific hycanthone resistant males from pre-formed pairs and vice versa. The frequency of changes is dependent on the magnitude of the excess single males competing with paired worms. The possible mechanics and the biological significance of mate changing are discussed.

Animals↗
PubMed1999

Effect of bile salts on oviposition in vitro by Schistosoma mansoni.

Adult pairs of Schistosoma mansoni were kept in culture in the presence or absence of various bile salts and the numbers of parasite eggs deposited in vitro were monitored for 2 weeks. The hydrophilic bile salt tauroursodeoxycholic acid (TUDCA) was found to produce a highly significant increase in the number of eggs deposited during the 1st week of culture. The hydrophobic bile salt taurochenodeoxycholic acid (TCDCA) and the intermediately hydrophobic salt taurocholate (TCA) produced more moderate increases. These results expand previous data showing that schistosomes kept in the presence of portal blood have higher oviposition rates than schistosomes kept in systemic blood.

Animals↗
PubMed1998

Infection with Schistosoma mansoni in mice induces changes in nociception and exploratory behavior.

In this study, CD-1 mice were infected percutaneously with 1600 cercariae of Schistosoma mansoni and their pain sensitivity and exploratory behavior were analyzed in well-standardized tests (hot-plate, hole-board, open-field, novel object investigation and black/white box). Schistosome infection produced body weight reduction, increased analgesia, induced changes in the number of fecal pellets emitted during the hole-board and the black/white tests, induced decreased locomotion in the open-field, decreased sniffing, rearing, wall-rearing and time spent in exploratory activity. The infection also lengthened the latency time to the first transition from the white into the black compartment in the black/white box, index of enhanced anxiety. The present findings indicate that the analgesia is one of the main effects of the disease suggesting that schistosome infection induces maladaptive response in exploratory behavior and in locomotor activity of the host associated with altered motivational and attentional levels. Furthermore, though mouse behavioral changes appear to be similar to those observed in parasite/host systems where the changes are supposed to be adaptive for the parasite, in the case of Schistosoma/mouse system, the changes in host behavior resulted to be not adaptive for the parasite.

Animals↗
PubMed1997

Role of TNF-alpha but not NGF in murine hyperalgesia induced by parasitic infection.

Using adult mice infected with the trematode Schistosoma mansoni, we observed that this infection induces both thermal hyperalgesia and an increase in the levels of nerve growth factor in the paws. To explore the mechanism involved in peripheral hypersensitivity during chronic infection, mice were infected with 60 cercariae of S. mansoni and injected 17 weeks later with nerve growth factor, anti-nerve growth factor or with other molecules known to be associated with hyperalgesic processes. The results of these studies showed that antibodies against tumor necrosis factor-alpha, but not against nerve growth factor, reduce thermal sensitivity in schistosome infected mice, suggesting that this cytokine but not NGF plays a crucial role in schistosome-induced thermal hyperalgesia. Treatments with anti-inflammatory drugs support this hypothesis.

Animals↗
PubMed1997

Removal of the submaxillary salivary glands and infection with the trematode Schistosoma mansoni alters exploratory behavior and pain thresholds in female mice.

In this study, CD-1 female mice, deprived of the submaxillary salivary glands, were infected with S. mansoni and their behavior was observed 15 weeks after infection, when the eggs of the parasite are present in the brain. Sialectomized infected mice showed changes in exploratory activity, sniffing, and wall-rearing in the open-field and in the black/white box, but no differences in pain sensitivity were observed on the hot plate. The present results suggest that the modifications in the behavior of sialectomized infected mice might be associated with the inability of the animals to cope with the aversive effects of the infection and, most probably, with modifications in the levels of polypeptides released into the bloodstream by the salivary glands, affecting the NGF-responsive cells of the nervous, endocrine, and immune systems.

Animals↗
PubMed1996

Schistosoma mansoni: influence of infection on mouse behavior.

Schistosoma mansoni infection in humans and animals induces abnormal neurobehavioral responses following granuloma formation. In mice, granulomas in the liver are observed 8 weeks after infection, while after 15-20 weeks, the presence of eggs and granulomas in the brain has been reported. In this study, outbred CD-1 female mice were infected with S. mansoni and examined in several behavioral tests (open field, novel object investigation, black/white box, and hot plate) 8 and 15 weeks after infection. The detected effects of schistosome infection were a reduction of body weight in 8-week infected mice, marked changes in exploration/activity, rearing, and wall-rearing in 8- and 15-week infected mice, an enhancement of sniffing and grooming in 8-week infected mice, and finally an increase in the threshold of pain response to the hot plate in 15-week infected mice. The results of the present study indicate that S. mansoni infection markedly alters exploratory behavior of mice, affecting particularly the vertical movements of the animals, and suggests that the differences in behavioral abnormalities between 8- and 15-week infected mice might be associated with modifications in the levels of nerve growth factor and cytokines induced by granulomas.

Analysis of Variance↗
PubMed1996

Chronic parasite infection in mice induces brain granulomas and differentially alters brain nerve growth factor levels and thermal responses in paws.

Schistosoma mansoni infection, both in humans and in animal models, is known to induce granulomas in the liver and intestine. It has also been reported that in humans the eggs of this parasite can reach the brain, causing psychiatric and neuropathological disorders. Whether this also occurs in rodents is unknown. To answer this question, mice were infected with this parasite and the central nervous system (CNS) examined at various time intervals. The results show that schistosomiasis induced granulomas in several regions of the CNS and increased nerve growth factor (NGF) levels in the cortex, hypothalamus and brain stem, but not in the hippocampus. The infection also caused paw hyperalgesia, as determined by the hot-plate test, and a local increase in NGF, but not in substance P. These findings indicate that the murine model of infection can be used for studying mechanisms leading to human neuroschistosomiasis and suggest that the neuropathological disorders and the sensory deficits observed in human schistosomiasis are associated with impaired levels of NGF in the peripheral and central nervous system.

Animals↗
PubMed1996

Evidence of a role for nerve growth factor in the effect of sialoadenectomy on body temperature of parasite-infected mice.

Mice infected with Schistosoma mansoni were used to investigate the role of the submaxillary salivary gland and nerve growth factor (NGF) in temperature response. The results showed that the infection increased (36.5 +/- 0.3 vs 35.7 +/- 0.2), while sialoadenectomy decreased (34.4 +/- 0.2 vs 35.1 +/- 0.2) body temperature. These temperature changes were associated with high or low circulating NGF levels, respectively. It was also found that infection altered the distribution of oxytocin-positive neurones in the hypothalamus and that administration of 20 mu g of purified NGF in normal mice raised (36.1 +/- 0.2 vs 35.1 +/- 0.2) and of NGF antibodies decreased (34.0 +/- 0.2 vs 35.1 +/- 0.2) body temperature. Taken together, these observations suggest that salivary NGF influences the temperature set-point in adult rodents, but the mechanism regulating these events remains to be elucidated.

Animals↗
PubMed1994

Schistosoma mansoni infection enhances the levels of NGF in the liver and hypothalamus of mice.

Schistosoma mansoni infection in adult mice is known to cause granulomas in the liver and intestine. Using a specific enzyme-linked immunoassay, it was found that Schistosoma mansoni infection enhances the level of nerve growth factor in the liver and surprisingly also in the hypothalamus. Exogenous administration of purified NGF antibodies inhibits NGF biological activity both in the hypothalamus and liver and drastically reduces the number of NGF-responsive cells, the mast cells, present in liver granuloma. These findings and those reported by others showing the effect of NGF on cells of the immune system support the hypothesis that this molecule plays a role in neuroendocrine-immune interactions.

Animals↗
PubMed1993

Schistosoma mansoni: genetic complementation analysis shows that two independent hycanthone/oxamniquine-resistant strains are mutated in the same gene.

Two drug-resistant strains of Schistosoma mansoni were compared in this study in order to decide whether they are both mutated in the same gene with respect to drug-sensitive schistosomes. One of the two strains was isolated in the laboratory, while the other one originated from a treated uncured patient and was subsequently drug selected in the laboratory. The approach consisted in a genetic complementation test performed essentially by crossing the two strains and assessing resistance in the progeny. Since no reappearance of drug sensitivity was detected in the progeny, it was concluded that the two strains failed to complement and were therefore mutated in the same gene. This finding suggests that a single step of drug activation operates in sensitive schistosomes and is ineffective in resistant worms.

Animals↗
PubMed1993

Double-blind study of nimesulide in divers with inflammatory disorders of the ear, nose and throat.

200 divers of either sex, aged 18 to 54 years, entered a double-blind study to compare the efficacy and tolerability of nimesulide 200 mg/day with those of seaprose S 60 mg/day in the treatment of nonbacterial inflammatory disorders of the ear, nose, and throat. At the end of the 1-week treatment period, both drugs were judged to be effective, with improvements and, in most cases, complete remission of all symptoms observed. Nimesulide showed greater clinical efficacy, and both drugs were well tolerated.

Adult↗
PubMed1992

Schistosoma mansoni: hycanthone/oxamniquine resistance is controlled by a single autosomal recessive gene.

Individual schistosomes of an hycanthone/oxamniquine-sensitive strain were crossed with individual schistosomes of the opposite sex and belonging either to the same sensitive population or to a different strain which exhibited high resistance to the two drugs. Schistosome crosses were performed by transfer of single worm pairs into the mesenteric veins of mice and the drug sensitivity/resistance of individual progeny worms was assessed using an in vitro test. Drug resistance behaved as an autosomal recessive trait, as shown by the results of the F1 and F2 generation and of the backcrosses. Drug-resistant worms appeared to be slightly less viable than their sensitive counterpart at all stages of the life cycle. The results are relevant for an interpretation of drug resistance and drug mechanisms and the approach used in this study may be applicable to different genetic markers in schistosomes.

Animals↗