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Biomedical subjects

L Ryan

Publications and source records attributed to L Ryan.

At least 127 records · Page 7Linked to original sources
PubMed1987

Leishmaniasis in Brazil. XXV. Sandfly vectors of Leishmania in Pará State, Brazil.

Leishmania of the braziliensis complex were isolated from various members of the squamiventris series sandflies, including Psychodopygus chagasi (Costa Lima), P.s.maripaensis (Ready et al.), P.s.squamiventris (Lutz & Neiva), and also P.ayrozai (Barreto & Coutinho) and Lutzomyia umbratilis Ward & Fraiha. Three different serodemes of Le.b.guyanensis Floch were isolated from Lu.anduzei Rozeboom, Lu.umbratilis and Lu.whitmani Antunes & Coutinho, simultaneously captured in the same area. Unidentified Leishmania were isolated from P.claustrei Abonnenc et al., and trypanosomes from Lu.pinottii Damasceno & Arouck and an unidentified species of Lutzomyia. A naturally infected female P.s.maripaensis transmitted a braziliensis complex Leishmania, by bite, to a hamster.

Animals↗
PubMed1986

Leishmaniasis in Brazil. XXII: Characterization of Leishmania from man, dogs and the sandfly Lutzomyia longipalpis (Lutz & Neiva, 1912) isolated during an outbreak of visceral leishmaniasis in Santarém, Pará State.

During epidemiological studies on an outbreak of visceral leishmaniasis in Santarém, Pará State, north Brazil, isolates of Leishmania from two children, three dogs and six naturally infected specimens of the sandfly Lutzomyia longipalpis were compared, biochemically, by starch-gel enzyme electrophoresis. They have proved to be indistinguishable from each other, and from a reference strain of Leishmania chagasi Cunha & Chagas, 1937 from a case of human visceral leishmaniasis from Bahia State, north-east Brazil, on their enzyme profiles for ASAT, ALAT, PGM, GPI, MDH and MPI. Lu. longipalpis is the principal, and possibly the only vector to man in the Amazon Region of Brazil.

Animals↗
PubMed1986

Peritonitis in continuous ambulatory peritoneal dialysis: analysis of an 8-year experience.

Experiences with peritonitis in a continuous ambulatory peritoneal dialysis (CAPD) program at a single center over 8 years were reviewed. Home-acquired peritonitis rates have been less than 1 episode per patient year since 1982. Gram-positive organisms continue to account for most episodes in a similar proportion. Actual known contamination could be pinpointed in only 7.4% of cases, but was strongly suspected in 35.8% of episodes. Exit site and/or tunnel infections were thought to have caused 20% of the cases. Intrinsic peritonitis probably accounted for 10.5%. Recurrence of peritonitis with the same organisms following cessation of antibiotics represented only 2.1% of cases.

Bacterial Infections↗
PubMed1986

Separation of female Psychodopygus wellcomei and P. complexus (Diptera: Psychodidae) by cuticular hydrocarbon analysis.

Psychodopygus wellcomei (Diptera: Psychodidae), vector of Leishmania braziliensis braziliensis - causative agent of cutaneous leishmaniasis in Brazil, cannot be distinguished from sympatric P. complexus either by morphometrics or isoenzyme profiles. We report here the use of cuticular hydrocarbon analysis in the successful separation of individual female P. wellcomei and P. complexus. This technique involves the use of gas liquid chromatography and discriminant function analysis.

Animals↗
PubMed1986

Chemical analysis of compounds extracted from the tergal "spots" of Lutzomyia longipalpis from Brazil.

The chemical composition of the compounds contained in the tergal spots of Lutzomyia longipalpis was investigated. Four populations of L. longipalpis were examined, originating from: Sobral, Ceará, Brazil (one spot and two spot populations), Santarém, Pará, Brazil (one spot) and Marajó Island, Pará, Brazil (one spot). The tergal spots were dissected out, extracted in hexane and analysed on a gas chromatograph/mass spectrometer. Two compounds were found, identical to compounds found in earlier studies, but there was no correlation between number of tergal spots and type of compound present. It was suggested that the number of tergal spots could not be used as a marker for reproductively isolated populations, and that analysis of the compound present within the spots might be necessary to characterize potentially good vector populations.

Animals↗
PubMed1985

Leishmaniasis in Brazil. XXI. Visceral leishmaniasis in the Amazon Region and further observations on the role of Lutzomyia longipalpis (Lutz & Neiva, 1912) as the vector.

Further evidence is presented incriminating the sandfly Lutzomyia longipalpis as the vector of Leishmania chagasi, the causative agent of American visceral leishmaniasis, in the Amazon Region of Brazil. During an outbreak of the disease in Santarém, Pará State, this insect was shown to be the only species of sandfly consistently present in and around the patient's homes, where it often occurred in very large numbers. Of 491 specimens dissected, 35 (7.14%) proved to be infected, and isolates of L. chagasi were made from 16 of 27 of these sandflies following the inoculation of the promastigotes into hamsters. Finally, the parasite was transmitted to four other hamsters which had been subjected to the bites of large numbers of wild-caught Lu. longipalpis. Isolates of Leishmania from Lu. longipalpis captures in Santarém, and in another focus of visceral leishmaniasis on the Island of Marajó, Pará, have been shown to be biologically and biochemically indistinguishable from the parasite infecting man, dogs and foxes in Pará, and from stocks obtained from man elsewhere in Brazil (Bahia and Ceará States).

Animals↗
PubMed1984

Trypanosome infection rates of Glossina spp. (Diptera: Glossinidae) in transitional forest-savanna near Bouaflé, Ivory Coast.

Tsetse, caught in biconical traps near Bouaflé, Ivory Coast in 1980-81, were examined for trypanosome infections. In a sample of 1138 non teneral Glossina palpalis s.l. there were infection rates of 12.2% (all infections) and 5.3% (mature infections). Female flies had a significantly higher infection rate than males. In G. palpalis only 3 (0.26%) salivary gland infections were detected, 62.3% of the mature infections were T. vivax-like and 71.4% of all infections were restricted to the midgut. The infection rate in forest/plantation caught G. palpalis was twice that of village caught flies. The infection rate increased with fly age and is correlated in female flies. In smaller samples of G.p. pallicera and G. fusca group flies the trypanosome infection rates were 37% and 46% respectively. In both these groups of flies 64.7% of infections were mature and were predominantly T. vivax-like and in females.

Animals↗
PubMed1984

The effect of trypanosome infection on a natural population of Glossina longipalpis Wiedemann (Diptera: Glossinidae) in Ivory Coast.

A population of Glossina longipalpis studied in the Southern Guinea savanna zone, Ivory Coast, showed marked differences between non-infected and infected females. Each fly was examined for age, reproductive condition, wear and tear, size and nutritional status. Infected flies were generally and sometimes significantly more active with lower fat reserves, residual bloodmeal and higher residual dry weight. Poorer nutritional condition may be due to energy metabolised by trypanosomes and possibly impaired feeding ability.

Animals↗