Search results for "Antiprotozoal"

Giant hepatic hydatid cyst as a cause of small bowel obstruction.

2006

Today, giant hydatid cysts are fairly rare even in endemic areas. We describe a case of an extremely large hydatid cyst of the liver that was causing massive compression of the neighboring organs, giving rise to a subocclusive syndrome of the intestine. After considering the various approaches available for the treatment of this disease, it was decided that radical surgery was still the best therapeutic choice, especially when extremely large cysts are involved. In particular, in clinical situations where it is difficult to perform radical surgical procedures, less aggressive surgery followed by drug treatment should be the treatment of choice.

Toxoplasmosis after hematopoietic stem cell transplantation.

2000

In immunocompromised individuals, toxoplasmosis mostly occurs as a reactivation of a latent infection, causing severe to life-threatening disease. Thus, recipients who are seropositive for Toxoplasma gondii before an allogeneic hematopoietic stem cell transplant (HCT) are at highest risk, although primary infections may also cause severe toxoplasmosis. The disease most often affects the central nervous system, but in HCT recipients other organs are involved in more than half of the cases. Because of the alteration of the immune response in these patients, serodiagnosis is not sufficiently reliable in the diagnosis of post-HCT toxoplasmosis, and direct detection of the causative agent is req…

Pediatric visceral leishmaniasis in Western Sicily, Italy: a retrospective analysis of 111 cases

2002

The clinical and epidemiological characteristics of 111 consecutive cases of visceral leishmaniasis identified from 1980 to 2000 in a Sicilian pediatric hospital were analyzed retrospectively. The mean age of the patients was 1.7 years. All children were HIV negative, but 15% were severely malnourished. Fever and splenomegaly were present in all cases and hepatomegaly in 101 (90.1%) cases. Thrombocytopenia and anemia were both observed in 78 (70.2%) cases and leukopenia in 47 (42.3%) cases. A bone marrow aspirate was obtained in all cases; Leishmania amastigotes were detected in 89 (80.2%) cases. Initial treatment consisted of meglumine antimoniate in 99 (89.2%) patients and amphotericin B …

Computational Identification of Chemical Compounds with Potential Activity against Leishmania amazonensis using Nonlinear Machine Learning Techniques.

2019

Leishmaniasis is a poverty-related disease endemic in 98 countries worldwide, with morbidity and mortality increasing daily. All currently used first-line and second-line drugs for the treatment of leishmaniasis exhibit several drawbacks including toxicity, high costs and route of administration. Consequently, the development of new treatments for leishmaniasis is a priority in the field of neglected tropical diseases. The aim of this work is to develop computational models those allow the identification of new chemical compounds with potential anti-leishmanial activity. A data set of 116 organic chemicals, assayed against promastigotes of Leishmania amazonensis, is used to develop the the…

In vitro leishmanicidal activity of pyrazole-containing polyamine macrocycles which inhibit the Fe-SOD enzyme of Leishmania infantum and Leishmania b…

2014

The in vitro leishmanicidal activity and cytotoxicity of pyrazole-containing macrocyclic polyamines 1-4 was assayed on Leishmania infantum and Leishmania braziliensis species. Compounds 1-4 were more active and less toxic than glucantime and both infection rates and ultrastructural alterations confirmed that 1 and 2 were highly leishmanicidal and induced extensive parasite cell damage. Modifications in the excretion products of parasites treated with 1-3 were also consistent with substantial cytoplasm alterations. Compound 2 was highlighted as a potent inhibitor of Fe-SOD in both species, whereas its effect on human CuZn-SOD was poor. Molecular modelling suggested that 2 could deactivate Fe…

Visceral leishmaniasis in a patient with Down syndrome

2006

Prediction of Aquatic Toxicity of Benzene Derivatives to Tetrahymena pyriformis According to OECD Principles

2016

Background: Many QSAR studies have been developed to predict acute toxicity over several biomarkers like Pimephales promelas, Daphnia magna and Tetrahymena pyriformis. Regardless of the progress made in this field there are still some gaps to be resolved such as the prediction of aquatic toxicity over the protozoan T. pyriformis still lack a QSAR study focused in accomplish the OECD principles. Methods: Atom-based quadratic indices are used to obtain quantitative structure-activity relationship (QSAR) models for the prediction of aquatic toxicity. Our models agree with the principles required by the OECD for QSAR models to regulatory purposes. The database employed consists of 392 substitut…

Machine learning-based models to predict modes of toxic action of phenols to Tetrahymena pyriformis.

2017

The phenols are structurally heterogeneous pollutants and they present a variety of modes of toxic action (MOA), including polar narcotics, weak acid respiratory uncouplers, pro-electrophiles, and soft electrophiles. Because it is often difficult to determine correctly the mechanism of action of a compound, quantitative structure-activity relationship (QSAR) methods, which have proved their interest in toxicity prediction, can be used. In this work, several QSAR models for the prediction of MOA of 221 phenols to the ciliated protozoan Tetrahymena pyriformis, using Chemistry Development Kit descriptors, are reported. Four machine learning techniques (ML), k-nearest neighbours, support vector…

Antiprotozoan lead discovery by aligning dry and wet screening: Prediction, synthesis, and biological assay of novel quinoxalinones

2014

Protozoan parasites have been one of the most significant public health problems for centuries and several human infections caused by them have massive global impact. Most of the current drugs used to treat these illnesses have been used for decades and have many limitations such as the emergence of drug resistance, severe side-effects, low-to-medium drug efficacy, administration routes, cost, etc. These drugs have been largely neglected as models for drug development because they are majorly used in countries with limited resources and as a consequence with scarce marketing possibilities. Nowadays, there is a pressing need to identify and develop new drug-based antiprotozoan therapies. In …

Pyrocoll, an Antibiotic, Antiparasitic and Antitumor Compound Produced by a Novel Alkaliphilic Streptomyces Strain

2003

A new secondary metabolite was detected in the culture extract of Streptomyces sp. AK 409 by HPLC-diode-array screening. The metabolite was identified as pyrocoll, which is known to be a constituent of cigarette smoke. Pyrocoll is known as a synthetic compound, but until now had not been isolated as a natural product from a microorganism. The compound showed biological activity against various Arthrobacter strains, filamentous fungi, several pathogenic protozoa, and some human tumor cell lines.