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R Romi

Publications and source records attributed to R Romi.

48 records · Page 3Linked to original sources
PubMed1992

[Anopheles in Italy: distribution on rice lands in the provinces of Grosseto and Siena].

The Laboratory of Parasitology of Istituto Superiore di Sanità acts as a coordinating centre for anophelism data collection in Italy, and collaborates with the health local authorities. This specific investigation takes into consideration several areas in the provinces of Grosseto and Siena, focusing attention on the rice fields, which are today the most important anopheline breeding sites in Maremma. The records collected in collaboration with the Department of Environmental Zoology (USL 28 Grosseto), show a high density of A. labranchiae, the potential malaria vector, in the coastal areas of Grosseto province, and a decreased susceptibility to some insecticides. Among the other anopheline species found, only A. atroparvus (the species most present on the inland hills of the provinces of Grosseto and Siena) show a remarkable density.

Animals↗
PubMed1991

[Antibody levels against circumsporozoitic protein of Plasmodium falciparum and their use as epidemiological indicators of malaria transmission in FIR of Comoros].

Epidemiological survey on prevalence of Plasmodium falciparum anti-circumsporozoite antibodies (Ab-CS) was carried out in 21 villages of Comoros FIR, at the beginning of 1988 rainy season. Evaluation of anopheline indoor resting densities was also carried out at the same time. Frequencies of antibody-positive subjects vary considerably in the different villages, according to the Anopheles gambiae and A. funestus densities per room, which are determined by ecological factors. Ab-CS prevalence varies in the sample population from 5.5% in 3-4 years children to 40% in those of 5 years. Starting from 6-7 years group, prevalence increased steadily reaching a plateau by 30 years of age. The detection of Ab-CS levels in a sample population is a good tool to evaluate malaria transmission levels, especially where the epidemiological situation does not allow a reliable entomological evaluation.

Adolescent↗
PubMed1985

Avermectins, MK-933 and MK-936, for mosquito control.

Two avermectins were shown to be effective as mosquito larvicides or when fed to adult female mosquitoes in sucrose solution or in blood. Larval LC50 values of compounds MK-933 and MK-936, expressed as parts per billion, were found to be 3.94 and 2.42 for Culex pipiens, 5.85 and 2.90 for Anopheles stephensi and 23.4 and 10.4 for Aedes aegypti. When fed to adult females of An. stephensi, Ae. aegypti or Cx quinquefasciatus, MK-933 at 2.8mg active ingredient per litre in sucrose solution caused complete mortality within 60 hours. When female mosquitos engorged blood from mice injected subcutaneously 12 hours previously with MK-933 at 82 mg a.i./kg, mortality rates after 36 hours were 100% for An. stephensi, over 60% for Ae. aegypti and over 50% for Cx quinquefasciatus. Thus the systemic insecticidal effect was greater against anopheline than against culicine female mosquitoes.

Aedes↗
PubMed1982

[Preliminary studies on levels of sensitivity to phosphoric esters in the Italian population of the Culex pipiens complex].

A preliminary survey of the susceptibility level to organophosphate (OP) insecticides in six populations of Culex pipiens from Central Italy has been carried out. The correlation between OP resistance and highly active esterase electromorphs has also been investigated. The bioassay and electrophoresis results show an association between OP resistance and the highly active esterase allele Est-3A and confirm what it was found in populations of C. pipiens from Southern France. Est-3A appears to be a reliable indicator of OP resistance in mosquitoes of italian C. pipiens.

Animals↗
PubMedDate not supplied

3D structure of kaliotoxin: is residue 34 a key for channel selectivity?

Kaliotoxin (KTX) is a natural peptide blocker of voltage-dependent K+ channels. The 3D structure of a truncated analogue of KTX (Fernandez et al. (1994) Biochemistry 33, 14256-14263) was determined by NMR spectroscopy and showed significant differences from structures established for other related scorpion toxins. A recent publication with the structure of the complete toxin (Aiyar et al. (1995) Neuron 15, 1169-1181) did not confirm these differences. In this communication we report NMR data for KTX at pH 3.0, 5.5 and 7.2 and the 3D structure obtained from data at pH = 5.5. Complete KTX displays a folding similar to that of other toxins with an alpha-helix and a beta-sheet linked by two disulphide bonds. The pKa of His 34 is anomalously low (4.7-5.2 depending on the buffer) owing to its interaction with two Lys residues (including the essential Lys 27), the charged N-terminus and the side chain of Met 29. Charged residues are placed symmetrically with respect to an axis that approximately coincides with one of the principal components of the moment of inertia of the toxin. His 34, which occupies a well-defined position between two conserved Cys, is located on the centre of a layer of charged groups. Positively and negatively charged residues are found at the same position in related toxins. It is suggested that electrostatic effects modulate the distances between positive charges in flexible side chains, contributing to the fine tuning of the selectivity toward different channel subclasses and that the approximate coincidence between the moment of inertia and the charge axis facilitate the approach of the toxin to the channel. The very low pKa of His 34 implies that it will be completely unprotonated at physiological pH.

Hydrogen Bonding↗
PubMedDate not supplied

Malaria epidemiological situation in Italy and evaluation of malaria incidence in Italian travelers.

BACKGROUND: Malaria was endemic throughout the country until it was eradicated nearly 50 years ago. Since then, mainly imported malaria cases have been reported to the National Health Service, with an increasing trend. The aim of this study was to present a detailed analysis of the current epidemiological situation of malaria in Italy, and to make a first attempt to calculate the incidence of malaria in Italian international travelers. METHODS: An archive of confirmed malaria cases is available at the Istituto Superiore di Sanità (ISS), the National Institute of Health of Italy, based on the mandatory report system. Data from each case report reported to the ISS from 1989 to 1997 have been analyzed. An evaluation of malaria incidence in Italian travelers has been also performed for the same period, based on the statistics provided by the Ministry of Transport. RESULTS: From 1989 to 1997, a total of 5,898 microscopically confirmed malaria cases have been reported. Of these, 5,773 (97.9%) were imported cases, 106 cases (1.8%) were relapses of Plasmodium vivax or Plasmodium ovale infections, and 19 cases (0.3%) occurred in subjects who had never been out of Italy. During the period of study, 55 deaths due to Plasmodium falciparum malaria were reported, with a mean fatality rate of 1.2%. Malaria incidence in Italians who traveled to Africa was estimated to be 1.5/1000. These figures appeared to be 10-20 and 30-40 times greater than that recorded in travelers to Asia (0.11/1000) and Central-South America (0.04/1000) respectively. CONCLUSIONS: From 1989 to 1997, there has been a remarkable increase in the total number of imported malaria cases in Italy, which reached a peak of more than 800 cases/year in 1997. A constant increase in the number of cases affecting foreigners has been reported, while the cases among Italians have remained stable. From 1989 to 1997 the number of Italian intercontinental travelers has nearly doubled, but malaria incidence has remained quite stable.

Adult↗
PubMedDate not supplied

Could malaria reappear in Italy?

Because of concern about the possible reintroduction of malaria transmission in Italy, we analyzed the epidemiologic factors involved and determined the country's malariogenic potential. Some rural areas in central and southern Italy have high receptivity because of the presence of potential malaria vectors. Anopheles labranchiae is probably susceptible to infection with Plasmodium vivax strains, but less likely to be susceptible to infection with P. falciparum. Its vulnerability is low because of the low presence of gametocyte carriers (imported cases) during the season climatically favorable to transmission. The overall malariogenic potential of Italy appears to be low, and reintroduction of malaria is unlikely in most of the country. However, our investigations showed that the malaria situation merits ongoing epidemiologic surveillance.

Animals↗
PubMedDate not supplied

[Larvivorous capacity of Barbus pobeguini and possibility of using this in the fight against Anopheles gambiae s.l].

Permanent breeding sites for Anopheles gambiae s.l. were found to occur in the urban area of Ouagadougou and to have some importance in the maintenance of vector populations. In these breeding places Barbus pobeguini was found widespread and larvivorous as indicated by the presence of remnants of A. gambiae in its stomach contents. The use of B. pobeguini would avoid the introduction of non-local larvivorous fishes. A series of trials carried out in laboratory conditions with B. pobeguini of different size, showed: 1) a remarkable capacity to ingest larvae (at different stages) of A. gambiae; 2) pronounced tendency by bigger B. pobeguini specimens to cope with bigger larvae; 3) an indifferent attraction to A. gambiae and Culex quinquefasciatus larvae.

Animals↗
PubMedDate not supplied

[Impregnation of uniforms with permethrin as a mean of protection of working personnel exposed to contact with hematophagous arthropods].

Laboratory bioassays were conducted to evaluate the effectiveness of permethrin-impregnated clothing against biting arthropods. Military battle dress uniforms were impregnated at a rate of 0.12-0.15 mg active ingredient (A.I.)/cm2. Gas chromatographic analysis of cloth patches treated showed that over 50% of the chemical remained after 6 cycles of washing. This amount of A.I. (0.06-0.07 mg/cm2) was effective in providing protection against Aedes aegypti and Ixodes ricinus. Mosquitoes and ticks were exposed respectively for 30 sec-3 min and 5-10 min to permethrin-impregnated uniforms: although the knockdown effect diminished with washing, the remaining permethrin provided 100% mortality of the mosquitoes and over 90% mortality of the ticks.

Aedes↗