Biomedical subjects

Ricardo Molina

Publications and source records attributed to Ricardo Molina.

5 recordsLinked to original sources

PubMed2006

Evaluation of the efficacy of a topically administered combination of imidacloprid and permethrin against Phlebotomus perniciosus in dog.

The phlebotomine sand fly Phlebotomus perniciosus is one of the main vectors of Leishmania infantum, responsible for human and canine leishmaniasis in the Mediterranean Basin. The objective of this study was to evaluate the repellent and insecticidal efficacy of imidacloprid 10% (w/v)/permethrin 50% (w/v) spot-on against sand flies (P. perniciosus) on dogs. The dogs used in this trial were laboratory-bred beagles: eight were impregnated with the solution (treated group), while the other eight were left untreated (control group). On day 0 the animals in the treatment group received 0.1 ml/kg body weight of the combination imidacloprid/permethrin spot-on. Dogs were exposed for 1h to about 100 female sand flies at weekly intervals for a period of 4 weeks, on day 1, 7, 14, 21, and 28 after applying the product. The repellency criterion was based on the feeding rate of sand flies in the treated compared to the untreated group. The insecticidal efficacy criterion was based on comparison of the survival rate of sand flies between the two groups. The product had an insecticidal efficacy on female sand flies of 53.2% (day 1), 49.4% (day 7), 15.1% (day 14), 13.2% (day 22), and 2.9% (day 29). The product showed a repellent effect of 97.7% (day 1), 96.3% (day 7), 96.5% (day 14), 92.7% (day 22), and 74.0% (day 29). Within the first week of application the insecticidal effect was significant; however it did not surpass 50%. On the other hand, the product showed a potent anti-feeding effect of over 90% during the first 3 weeks of this trial. Therefore, the application of this product every 3 weeks would be a good tool to significantly reduce sand fly bites over the period of transmission of vectorial diseases such as leishmaniasis and several arbovirosis such as Toscana virus.

Animals↗

PubMed2004

Canine leishmaniasis.

Canine leishmaniasis is caused by Leishmania infantum (syn. L. chagasi, in America) and is transmitted by the bite of phlebotomine sand flies. Infected dogs constitute the main domestic reservoir of the parasite and play a key role in transmission to humans, in which the parasite produces visceral leishmaniasis. The increasing awareness that control of the human disease depends on effective control of canine leishmaniasis has promoted, in the last few years, research into leishmanial infection in dogs. Newly available specific reagents and molecular tools have been applied to the detailed investigation of canine leishmaniasis and important advances have been made in elucidating the epidemiology and pathology of the disease. These new findings have led to better understanding of the disease, and have also helped in the development of new diagnostic methods and control measures against the infection, such as insecticide-impregnated collars for dogs, new drugs and treatment protocols, and second generation vaccines, with the hope of not only reducing the heavy burden of the disease among dogs but also reducing the incidence of human visceral leishmaniasis.

Animals↗

PubMed2004

[Clinicopathological features of gallbladder polyps and adenomas].

BACKGROUND: Chile has a high frequency of gallbladder cancer. Polyps are common lesions of gallbladder mucosa but there is little information about their morphological features. AIM: To report the clinical and pathological features of 219 gallbladder polyps. MATERIAL AND METHODS: Cholecystectomites samples in which a polypoid lesion was diagnosed microscopically. In all cases, complete clinical information and digitalized images of the complete surgical specimens was reviewed. RESULTS: In a period of 10 years, 21,412 gall-bladders were processed. Among these, 884 carcinomas were diagnosed and in 219 cases (1%) a polyp was found. One hundred and eighty three patients were females (mean age 49.3 years) and 36 males (mean age 53.4 years). The preoperative diagnosis of gallbladder polyp wars done only in 26 cases (12%). Eighty five percent of polyps were non-neoplastic (metaplastic in 32%, cholesterol in 29%, hyperplastic in 22% and inflammatory in 2%). The remaining 15% were adenomas. Seventy five percent of non-neoplastic polyps were located in the proximal half of the gallbladder and 88% of adenomas in the distal half. Ninety five percent of non-neoplastic polyps measured less than 10 mm. Among adenomas, 47% measured less than 5 mm and 28% more than 10 mm. Smaller polyps were of cholesterol and larger polyps were adenomas. Eight adenomas were associated with an adenocarcinoma, two had less than 5 mm length. Mean age of patients with adenomas associated to cancer was higher than patients with pure adenomas (64.6 and 44.3 years respectively, p > 0.001). CONCLUSIONS: There are size and location differences between non neoplastic polyps and adenomas. Adenomas associated to cancer may measure less than 5 mm. Therefore the polyp size criteria to decide surgical behavior in symptomatic gallstone patients may be misleading.

Adenocarcinoma↗

PubMed2003

[Antiparasite therapy].

The lack of any parasite vaccine makes prevention against parasitic diseases to be based, as in the past, in ecological measures such as the environmental health and vector control to interrupt the biological cycle; on the other hand, it is also based in anti-parasite drugs. Once the disease has been acquired it is just possible to take medication. Studies on the way of action allow to understand more about the physiology of the parasite and, on the other hand, to understand better the physiology of the parasite allows to design new more effective drugs. However, the vast majority of these new drugs have been obtained thanks to intelligent and selective screening of generic molecules more than from the result of the knowledge of the biochemistry of the parasite. Despite all this, it is well known the mechanisms of action of many antiparasite drugs which have led us, when possible, to the discussion about possible targets to give an idea of how the rational approximation to design new medicaments is done.

Antiparasitic Agents↗

PubMed2001

Chemical Modifications on Human Hair Studied by Means of Contact Angle Determination.

Wetting properties of a solid surface can change as a consequence of chemical treatment. There is a relationship between the molecular structure of a surface and the macroscopic properties of this surface such as wetting and adhesion. Information on the surface energy of a solid was obtained by calculating polar and dispersion force contributions by means of contact angle determination. The superficial modification undergone by human hair treatments with or without hydrogen peroxide at alkaline pH was studied by means of wetting force measurements. The wetting increase in treated human hair fibers was analyzed following the Hüttinger method using contact angle data, taking into account the acid-base and dispersion components of the total wetting adhesion work. The hydrogen peroxide treatment at alkaline pH leads to a partial removal of hydrocarbon chains and to the formation of ionic groups (cysteic acid residues) on the outer scale cell surface. The latter phenomenon was observed by means of an increase in the acid-base adhesion work versus water wetting liquid at alkaline pH. Copyright 2001 Academic Press.

Journal Article↗