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Biomedical subjects

F Frati

Publications and source records attributed to F Frati.

36 records · Page 2Linked to original sources
PubMed2003

The mitochondrial genome of the olive fly Bactrocera oleae: two haplotypes from distant geographical locations.

The complete sequence of the olive fly (Bactrocera oleae) mitochondrial genome has been determined. Two independent haplotypes, from flies of distant geographical origin (Italy and Portugal) were completely sequenced. The molecule is 15815 bp long, and shows the gene content and organization typical of insects, namely thirteen protein coding genes (PCGs) encoding proteins involved in oxidative phosphorylation, two rRNAs, twenty-two tRNAs and a long (949 bp) noncoding region. The genomes of the two fly specimens share the same arrangement, differing by a mere thirty-one point mutations. The differences are mostly transitions (26) and synonymous substitutions in PCGs (21). The two new sequences are compared with others already present in the database.

Animals↗
PubMed2003

Asthma prevalence and drug prescription in asthmatic children.

A cross-sectional study was conducted on among 28,856 children aged from birth to 14 years to determine the prevalence of asthma and assess its treatment in a sample of asthmatic children. Children diagnosed with asthma were identified by a sensitive algorithm applied to the information stored in the computerized medical records between 1997 and 1998. Pediatricians then reviewed and validated the diagnosis. Specific information was obtained, after age stratification under 5 yrs and over 6 ys, from the medical records and by interview regarding their personal details and treatment of asthmatic patients. In all, 1,263 cases of asthma were identified (64% males) with a prevalence of 6.3% among males and 4% among females in under 5 year-olds, and 3.9% for males and 2.1% for females in over 6 year-olds. The prevalence of asthma diagnosed directly by the pediatrician was consequently higher among under 5 year-olds, in both genders, than among the older children. Contrary to the international guidelines, pediatricians prescribed more oral corticosteroids and nebulized short-acting beta-2 agonists for children under 5 ys olds than for over 6 year-olds (13.3% Vs 4.8% and 25% Vs 10.9%, respectively, p < 0.001). For the > or = 6 year-olds, the most commonly prescribed treatments were oral antihistamines (13.9% Vs 12.6%), inhaled corticosteroids via metered-dose inhaler (30.8% Vs 28.7%) and sodium cromoglycate (12.1% Vs 4.8%, p < 0.001).

Adolescent↗
PubMed2003

A model for management of sublingual immunotherapy.

UNLABELLED: High dose sublingual immunotherapy (SLIT) is generally well tolerated, since most side effects are local reactions involving the oral or gastrointestinal mucosa. However, such reactions, if not adequately managed, may lead the patient to stop SLIT. OBJECTIVE: We introduce a method to manage side effects of SLIT, which was successfully applied on a group of children undergoing SLIT. METHODS: SLIT was performed with Staloral 300 (Stallergénes, Antony, France) by the schedule in 11 days indicated by the manufacturer with a tap dose of 8 pressures of the 300 IR concentration. The treatment was managed by flow charts suggesting adjustment of dose, regimen, or kind of assumption depending on the kind of reactions (oral, gastrointestinal, respiratory). RESULTS: An overall number of 200 children (120 males, 80 females, mean age 9 yrs, range 3-14 yrs) were treated. Of them, 155 (77.5%) had no reaction, while 45 (22.5%) had side effects, consisting of 20 oral itching or burning, 15 gastrointestinal symptoms and 10 rhinitis. No systemic reaction was observed. All side effects were successfully managed by the proposed method, thus reaching the maintenance dose in all patients but one, reporting repeated intense oral itching, who stopped SLIT. CONCLUSIONS: High dose SLIT is well tolerated in treated patients. In most patients with side effects, which are mainly oral itching or gastrointestinal disturbances due to contact with the allergen extract, a proper management allows to reach the maintenance dose with no further reactions.

Administration, Sublingual↗
PubMed2003

Long-term cetirizine treatment may reduce new sensitisations in allergic children: a pilot study.

Experimental data demonstrate that mite allergy is characterized by persistent chronic inflammation. This suggests that long-term continuous treatment may be included in the global strategy of allergy management as recently reported. Moreover, most of allergic subjects show polysensitisation. We conducted a study to investigate whether a long-term cetirizine treatment may reduce the occurence of new sensitisations in children with mite allergy. This study was initially double-blind, randomized, and placebo-controlled, with two parallel groups of 10 children with mite allergy receiving either cetirizine or placebo daily. All children could assume cetirizine as rescue medication (i.e. symptomatic treatment). After six months, parents of continuously-treated children decided to continue the treatment for 3 years. Other subjects continued to assume cetirizine on symptomatic basis. All children were prospectively followed for other 3 years. Outcome measure was skin prick test, yearly performed. Cetirizine-continuously-treated group showed a significant lower incidence of new sensitisations (p = 0.002). In conclusion, cetirizine administered daily for prolonged periods (i.e. 3 years) may decrease the development of new sensitisations in monosensitised children, showing a potential effect of tertiary prevention of allergy.

Animals↗
PubMed2003

Nasal cytokine modulation by montelukast in allergic children: a pilot study.

BACKGROUND: Allergic rhinitis and asthma are characterized by chronic inflammation due to a Th2 cytokine polarization. Leukotrienes receptor antagonists have been shown to be effective in both diseases. OBJECTIVE: Aim of the study was to evaluate the modulation by the antileukotriene montelukast on Th2 and Th1 cytokines in allergic rhinitis. METHODS: Fourteen school children affected by persistent allergic rhinitis (PAR) and exercise-induced asthma (EIA) underwent a nasal lavage before and after a two-week treatment with montelukast. A panel of cytokines, including IL4, IL13, and IFN gamma, was measured by immunoassay on nasal lavage samples. RESULTS: Montelukast treatment induced a significant decrease of IL4 and IL13 levels (p < 0.001, for both comparisons), and a significant increase of IFN gamma (p < 0.001). CONCLUSIONS: Montelukast treatment reversed a typical Th2 cytokine pattern (IL4 and IL13) toward a Th1 (IFN gamma) predominance in children with PAR and EIA. This effect could be considered relevant for long term allergic inflammation control and of interest when treating EIA with concomitant PAR.

Acetates↗
PubMed2001

Sublingual tryptase and ECP in children treated with grass pollen sublingual immunotherapy (SLIT): safety and immunologic implications.

BACKGROUND: The clinical safety of sublingual immunotherapy (SLIT) has been repeatedly confirmed; nevertheless, the possible onset of local oral symptoms is still a concern, and nothing is known about the pathogenesis of this effect. We aimed to determine whether the administration of SLIT in allergic children can evoke an IgE-mediated reaction, by measuring the levels of sublingual tryptase and ECP. METHODS: Thirty children (7-12 years old) with allergic rhinitis/asthma due to grass pollen were prescribed SLIT. In these children, an allergen-specific nasal challenge was performed, and nasal tryptase and ECP were measured before and after. Sublingual ECP and tryptase were also assessed before the SLIT, after 1 month, and after 6 months of treatment. Ten matched allergic children and 10 healthy ones served as controls for the baseline levels of sublingual ECP and tryptase. RESULTS: The levels of nasal tryptase and ECP significantly increased after nasal challenge (P<0.001), whereas no change during the SLIT course (at the beginning, after 1 month, and after 6 months) could be detected in sublingual tryptase either before or after SLIT administration. The sublingual ECP significantly decreased after 6 months of SLIT. The baseline levels of nasal tryptase and ECP were significantly higher in allergic subjects than in healthy controls, as was the level of sublingual ECP. CONCLUSIONS: In the presence of an IgE-mediated reaction (ASNC), a significant increase of tryptase and ECP can be seen. When SLIT is administered, such a phenomenon does not occur; therefore, SLIT does not elicit any IgE reaction in the mouth. It is noteworthy that allergic subjects display higher levels of nasal ECP and tryptase than healthy subjects, even when symptom-free, and these observations may indicate the presence of subclinical inflammation.

Administration, Sublingual↗
PubMed2001

Sperm ultrastructure and spermiogenesis in the relic species Tricholepidion gertschi Wygodzinsky (Insecta, Zygentoma).

The silverfish Tricholepidion gertschi is of interest in that it is the most basal representative of Zygentoma. An ultrastructural study of its spermiogenesis was performed to find out whether there are traits which resemble those of other, more advanced insects. This was found to be the case; spermiogenesis can be considered to be of a common insectan type, leading to the formation of elongated sperm cells with acrosome, nucleus, neck region and a tail with axoneme and two mitochondrial derivatives. Total cell length, 50 microm, is short for an insect. There are some specializations, which probably represent autapomorphies. The acrosome has a posterior canal or cleft that makes a U-turn. The centriole adjunct forms a prominent post-nuclear ring surrounding the centriole and have a posterior extension, and further originates nine intertubular fibers with a longitudinal periodicity and two accessory bodies. The mitochondrial derivatives have five rows of regularly spaced cristae within a crystalline matrix. The axoneme has accessory tubules consisting of 16 protofilaments, formed at the B-tubules of the doublets and placed at some distance from them in the posterior part of the sperm tail.

Animals↗
PubMed2001

Binucleate and biflagellate spermatozoa in Tricholepidion gertschi Wygodzynsky (Insecta, Zygentoma).

The phenomenon of sperm pairing is known from some species of the apterygotan insect order Zygentoma, and has been described as the close apposition of two sperm cells. When released from the testes, they are single cells; pairing taking place in the deferent ducts. In a study of the relic species Tricholepidion gertschi, Zygentoma, sperm pairing was found to be due to a true fusion of two partners along their entire sperm head regions. The spermatozoon thus formed has two acrosomes, two nuclei and two separate sperm tails. The biflagellate spermatozoon swims with coordinated movements of its two flagella only when the two flagella lie close together but is totally uncoordinated when separate. The spermatozoon is about 50 microm long, thus much shorter than those of related apterygotan species. The mechanism of sperm cell fusion is unclear, although it appears that a 55-nm wide layer of electron dense substance, here termed the peripheral lamina, may play a role in delimiting the extent of sperm fusion.

Acrosome↗
PubMed2001

The complete mitochondrial DNA sequence of the basal hexapod Tetrodontophora bielanensis: evidence for heteroplasmy and tRNA translocations.

We present the complete 15,455-nt mitochondrial DNA sequence of the springtail Tetrodontophora bielanensis (Arthropoda, Hexapoda, Collembola). The gene content is typical of most metazoans, with 13 protein-coding genes (PCGs), 2 genes encoding for ribosomal RNA subunits, and 22 tRNA genes. The nucleotide sequence shows the well-known A+T bias typical of insect mtDNA; its A+T content is lower (72.7%) than that observed in other insect species, but still higher than that in other arthropodan taxa. The bias appears to be uniform across the whole molecule, unlike other insect taxa, which show increased A+T content in the so-called A+T-rich region. However, the bias is slightly higher in the third codon positions of the PCGs (81.4%). Anomalous initiation codons have been observed in the nad2 and the cox1 genes. In the latter, the ATTTAA hexanucleotide is suggested to be involved in the initiation signaling. All tRNAs could be folded into the typical cloverleaf secondary structure, but the tRNA for cysteine appears to be missing the DHU arm. Long tandemly repeated regions (193 nt) were found in the A+T-rich region, which in turn was shown to have the possibility of forming a complex array of secondary structures. One of these structures encompassed the junction between the repeats. The A+T-rich region was also interesting in that it showed heteroplasmy in the number of repeats. Three haplotypes were found, possessing 2, 3, and 4 identical repeats, respectively. The order of protein coding and rRNA genes in the molecule was determined and was identical to that of all insects studied so far. However, two tRNA translocations were found which were unprecedented among Arthropoda. These involved the trnQ, which was found between the rrnS and the A+T-rich region, and the trnS(ucn), which was located between trnM and trnI. A preliminary phylogenetic analysis based on the amino acid sequence of the PCGs failed to find support for the monophyly of Hexapoda.

Animals↗
PubMed2000

Large amounts of genetic divergence among Italian species of the genus Orchesella (Insecta, collembola) and the relationships of two new species.

The phylogenetic position of two putative new species of the collembolan genus Orchesella was investigated by comparison with four other Italian species of the genus using a fragment of the mitochondrial gene encoding for subunit I of cytochrome c oxidase (COI). The gene showed the well-known A + T bias, typical of insect mitochondrial DNA, although A + T content was not as high as that observed in species belonging to more derived insect orders. The large number of variable sites in 3rd codon positions (85.2% variable) suggested that these sites contain significant homoplasy due to multiple hits. Despite the lack of morphological differentiation, the COI portion examined shows remarkable levels of genetic divergence between the putative species and their closest relatives. Phylogenetic analysis suggests that one of the putative new species is related to O. villosa, whereas the other is included in a clade with O. cincta and O. ranzii. The species O. chiantica appears to be related to O. villosa, agreeing with previous allozyme data.

Animals↗
PubMed1999

Chromosome elimination and sex determination in springtails (Insecta, Collembola).

A post-zygotic mechanism of sex determination is described in the two symphypleonans Dicyrtomina ornata (Nicolet) and Ptenothrix italica Dallai. The process consists of the loss of two sex chromosomes from the male embryo. At the end of the first meiotic division of spermatogenesis, a second chromosome elimination occurs, allowing half the secondary spermatocytes, later transformed into spermatids, to receive a complete haploid set of chromosomes. The secondary spermatocytes, which receive an incomplete set of chromosomes, degenerate. Males of the two collembolan species, therefore, produce a reduced number (50%) of spermatozoa. Females of D. ornata have 2n = 12 and males 2n = 10 chromosomes; females of P. italica have 2n = 14 and males 2n = 12 chromosomes. In both species, oogenesis proceeds normally and chromosomes pair and form chiasmata in meiotic prophase. The adaptive significance of this post-zygotic mechanism of sex determination is discussed. The mechanism seems to be a characteristic feature of the suborder Symphypleona. The neanurid Arthropleona Anurida maritima (Guérin), which was studied for comparative analysis, has 2n = 8 chromosomes and normal spermatogenesis producing haploid nuclei with four chromosomes. J. Exp. Zool. (Mol. Dev. Evol.) 285:215-225, 1999.

Animals↗
PubMed1997

Evolution of the mitochondrial cytochrome oxidase II gene in collembola.

The sequence of the mitochondrial COII gene has been widely used to estimate phylogenetic relationships at different taxomonic levels across insects. We investigated the molecular evolution of the COII gene and its usefulness for reconstructing phylogenetic relationships within and among four collembolan families. The collembolan COII gene showed the lowest A + T content of all insects so far examined, confirming that the well-known A + T bias in insect mitochondrial genes tends to increase from the basal to apical orders. Fifty-seven percent of all nucleotide positions were variable and most of the third codon positions appeared free to vary. Values of genetic distance between congeneric species and between families were remarkably high; in some cases the latter were higher than divergence values between other orders of insects. The remarkably high divergence levels observed here provide evidence that collembolan taxa are quite old; divergence levels among collembolan families equaled or exceeded divergences among pterygote insect orders. Once the saturated third-codon positions (which violated stationarity of base frequencies) were removed, the COII sequences contained phylogenetic information, but the extent of that information was overestimated by parsimony methods relative to likelihood methods. In the phylogenetic analysis, consistent statistical support was obtained for the monophyly of all four genera examined, but relationships among genera/families were not well supported. Within the genus Orchesella, relationships were well resolved and agreed with allozyme data. Within the genus Isotomurus, although three pairs of populations were consistently identified, these appeared to have arisen in a burst of evolution from an earlier ancestor. Isotomurus italicus always appeared as basal and I. palustris appeared to harbor a cryptic species, corroborating allozyme data.

Amino Acid Sequence↗
PubMed1996

Investigation on the taxonomic status of Steganacarus magnus and Steganacarus anomalus (Acari:Oribatida) using mitochondrial DNA sequences.

To test the previously suggested synonymization of S. anomalus with the older S. magnus, a fragment of the mitochondrial COI gene was amplified via the polymerase chain reaction and sequenced. The sequence variation was examined in a total of 327 base pairs for four steganacarid mite populations, two of which belong to S. anomalus, one to S. magnus and one to S. hirsutus. The sequence variation suggests that S. magnus and S. anomalus are not distinct species and that the population from Fioreta (Siena) is more similar to that from Apulia than to the nearer population from the Apuan Alps. The results show the usefulness of this molecular approach as a tool for determining taxonomic status and for suggesting faunistic movements in the past millions of years.

Amino Acid Sequence↗
PubMedDate not supplied

An extensively hydrolysed cow's milk formula improves clinical symptoms of gastroesophageal reflux and reduces the gastric emptying time in infants.

BACKGROUND: About 20 % of infants fed with breast-milk substitutes suffer from Gastro Esophageal Reflux (GER) and 1/3 of them also show Cow's Milk Allergy (CMA) symptoms. METHODS: We planned this study to assess by dynamic echography the usefulness of an Extensively Hydrolysed Cow's Milk Formula (eHF) in infants suffering from GER. Ten infants showing GER symptoms and 10 normal babies, all fed with breast-milk substitutes, were enrolled. Clinical symptom scores related to GER were assessed for one week. The Gastric Emptying Time (GET) was determined by means of dynamic echography after feeding with cow's milk-derived formulae and again after a week feeding with eHF in subjects previously showing GER symptoms. RESULTS: All infants with a clinical diagnosis for GER showed an abnormally high average GET in comparison to normal subjects (205 vs 124 min, p = 0.000). Switching to the eHF led to a significant clinical improvement (p = 0.0039) especially in babies skin-test and RAST positive to cow's milk, and to a significant decrease toward the normal value of the GET (167 min, p < 0.001). CONCLUSIONS: The eHF tested improves GER symptoms in infants suffering from this disease. Our experience confirms and supports the use of dynamic echography as a reliable, simple, and non-invasive diagnostic method for infants with an increased GET associated with clinical symptoms of GER.

Animals↗
PubMedDate not supplied

Aberrant spermatogenesis and the peculiar mechanism of sex determination in Symphypleonan Collembola (Insecta).

Light and electron microscopy evidence have been obtained to describe the peculiar spermatogenesis in the collembolan species Sminthurus viridis and Allacma fusca (Sminthuridae). In these two species, the two sexes differ for the lack of two chromosomes (the sex chromosomes) in males (males, 2n = 10; females, 2n = 12). While oogenesis seems to proceed normally, spermatogenesis is peculiar because the two daughter cells of the first meiotic division have different chromosome numbers (six and four). The cell receiving four chromosomes degenerates, while the cell receiving six chromosomes completes meiosis and produces identical spermatozoa (n = 6). At fertilization, pronuclei with six chromosomes fuse together to form zygotes with 2n = 12. Male embryos must lose two sex chromosomes during the first zygotic mitosis, as all male cells have 2n = 10 chromosomes. The sex chromosome system of these species can be identified as X1X1X2X2:X1X20. Electron microscopy observations show that the same peculiar spermatogenesis occurs also in two others species of the same family, Caprainea marginata and Lipothrix lubbocki. The peculiar sex determination system described is similar but not identical to what is observed in other insect orders, and it may represent an evolutionary step toward parthenogenesis. It is suggested that this peculiar spermatogenesis is common to all Symphypleona.

Animals↗
PubMedDate not supplied

Grass pollen specific sublingual/swallow immunotherapy in children: open-controlled comparison among different treatment protocols.

BACKGROUND: sublingual-swallow immunotherapy has been recognized as safe and effective in adults. Different treatment schedules have been proposed and used, but the current experience in children is insufficient. We carried out a study to evaluate the clinical efficacy and the safety in children allergic to grass pollen, following different schedules. METHODS: an open study was performed with 3 parallel treated groups and a control group, each including 12 children suffering from rhinoconjunctivitis due to grass pollen. The patients underwent either a preseasonal treatment or a pre-coseasonal treatment during the grass pollen season. The analysis of the clinical outcome was based on the number of days with symptoms and/or drug consumption in the pollen peak month. RESULTS: significantly less days with symptoms and/or drug intake in all of the groups submitted to SLIT in comparison to the control group were found (p < 0.0001). Among the three schedules used, the best clinical results were obtained with the two pre-coseasonal treatments (p < 0.0001), with a preference for the schedule with the lowest maintenance dose according to the drug intake (p = 0.0267). Two patients belonging to the coseasonal schedule with the highest maintenance dose interrupted the treatment because of systemic mild side effects. CONCLUSIONS: our data suggests that in children with rhinoconjunctivitis to grass pollen, SLIT is effective and well tolerated and that the pre-coseasonal schedule should be preferred to the preseasonal treatment. According to our data, the best maintenance dose during the pollen season for children, both for tolerance and clinical outcome, corresponds to 0.4 microg of the grass major allergen Group 5 administered three times a week.

Administration, Sublingual↗
PubMedDate not supplied

Sublingual reactivity to rBET V1 and rPHL P1 in patients with oral allergy syndrome.

Oral Allergy Syndrome (OAS) in patients with pollen-induced rhinoconjunctivitis is caused by specific IgE recognizing cross-reacting epitopes of fruits and plants, which were clearly shown in vitro, but failed to be demonstrated in vivo by cross-challenges in the target organs. Considering the hypothesis of degradation of such epitopes in natural extracts, challenges with recombinant pollen allergens were done to evaluate the reactivity of the oral mucosa in OAS patients. Seventeen patients with OAS and rhinitis from birch (10) and grass pollen (7) and 10 non-atopic controls were studied by skin prick tests (SPT), allergen specific nasal challenges (ASNC) and allergen specific sublingual challenges (ASSC) with birch and timothy extracts and with rBet v1 and rPhl p1 at increasing concentrations from 1 to 1000 mcg/ml. None of the healthy subjects in the control group had any positive test for birch and timothy extracts or for recombinant allergens. In the OAS group the following results were observed: SPTs with recombinant allergens were positive in all patients, mostly at 10 mcg/ml concentration; ASNC with rBet v1 were positive in all patients, mostly at 100 mcg/ml; ASSC with natural pollen extracts were positive in only 2 of 17 patients, but in 15 of 17 with rBet v1 and rPhl p1, mostly at 500 mcg/ml and 1000 mcg/ml. ASSC with rBet v1 and rPhl p1 were positive with a mean concentration of 677 and 533 mcg/ml, respectively. The results of sublingual challenges with rBet v1 and rPhl p1 showed the in vivo cross-reactivity between pollens and foods in patients with OAS, but high concentrations of the recombinant allergens were needed to reproduce oral symptoms, thus explaining the failure of challenges performed with natural extracts, which have concentrations of major allergens lower than 50 mcg/ml. This indicates that sublingual mucosa is much less reactive to allergens than other surfaces, such as skin and nasal mucosa, probably because of its anatomic and immunologic peculiarity.

Administration, Sublingual↗