New synthetic molecules incorporated into polymeric micelles used for treatment against visceral leishmaniasis

Treatment against visceral leishmaniasis (VL) presents problems, mainly related to drug toxicity, high cost and/or by emergence of resistant strains. In the present study, two vanillin synthetic derivatives, 3 s [4-(2-hydroxy-3-(4-octyl-1H-1,2,3-triazol-1-yl)propoxy)-3-methoxybenzaldehyde] and 3 t [4-(3-(4-decyl-1H-1,2,3-triazol-1-yl)-2-hydroxypropoxy)-3-methoxybenzaldehyde], were evaluated as therapeutic candidates in a murine model against Leishmania infantum infection. Molecules were used pure (3 s and 3 t) or incorporated into Poloxamer 407-based micelles (3 s/M and 3 t/M) in the infected animals, which also received amphotericin B (AmpB) or Ambisome® as control. Results showed that 3 s/M and 3 t/M compositions induced a Th1-type immune response in treated animals, with higher levels of IFN-γ, IL-2, TNF-α, IL-12, nitrite, and IgG2a antibodies. Animals presented also low toxicity and significant reductions in the parasite load in their spleens, livers, bone marrows and draining lymph nodes, as compared as control groups mice, with the evaluations performed one and 30 days after the application of the therapeutics. In conclusion, preliminary data suggest that 3 s/M and 3 t/M could be considered for future studies as therapeutic agents against VL.

Treatment using vanillin-derived synthetic molecules incorporated into polymeric micelles is effective against infection caused by Leishmania amazonensis species

Treatment against leishmaniasis presents problems, mainly due to the toxicity of the drugs, high cost, and the emergence of resistant strains. A previous study showed that two vanillin-derived synthetic molecules, 3s [4-(2-hydroxy-3-(4-octyl-1H-1,2,3-triazol-1-yl)propoxy)-3-methoxybenzaldehyde] and 3t [4-(3-(4-decyl-1H-1,2,3-triazol-1-yl)-2-hydroxypropoxy)-3-methoxybenzaldehyde], presented antileishmanial activity against Leishmania infantum, L. amazonensis, and L. braziliensis species. In the present work, 3s and 3t were evaluated to treat L. amazonensis-infected mice. Molecules were used pure or incorporated into Poloxamer 407-based micelles. In addition, amphotericin B (AmpB) and its liposomal formulation, Ambisome®, were used as control. Animals received the treatment and, one and 30 days after, they were euthanized to evaluate immunological, parasitological, and biochemical parameters. Results showed that the micellar compositions (3s/Mic and 3t/Mic) induced significant reductions in the lesion mean diameter and parasite load in the infected tissue and distinct organs, as well as a specific and significant antileishmanial Th1-type immune response, which was based on significantly higher levels of IFN-γ, IL-12, nitrite, and IgG2a isotype antibodies. Drug controls showed also antileishmanial action; although 3s/Mic and 3t/Mic have presented better and more significant parasitological and immunological data, which were based on significantly higher IFN-γ production and lower parasite burden in treated animals. In addition, significantly lower levels of urea, creatinine, alanine transaminase, and aspartate transaminase were found in mice treated with 3s/Mic and 3t/Mic, when compared to the others. In conclusion, results suggest that 3s/Mic and 3t/Mic could be considered as therapeutic candidates to treat against L. amazonensis infection.

In vitro evaluation of antileishmanial activity, mode of action and cellular response induced by vanillin synthetic derivatives against Leishmania species able to cause cutaneous and visceral leishmaniasis

The treatment against leishmaniasis presents problems, mainly due to their toxicity of the drugs, high cost and/or by the emergence of parasite resistant strains. In this context, new therapeutics should be searched. In this study, two novel synthetic derivatives from vanillin: [4-(2-hydroxy-3-(4-octyl-1H-1,2,3-triazol-1-yl)propoxy)-3-methoxybenzaldehyde] or 3s and [4-(3-(4-decyl-1H-1,2,3-triazol-1-yl)-2-hydroxypropoxy)-3-methoxybenzaldehyde] or 3t, were evaluated regarding their antileishmanial activity against distinct parasite species able to cause cutaneous and visceral leishmaniasis. Results showed that compounds 3s and 3t were effective against Leishmania infantum, L. amazonensis and L. braziliensis promastigote and amastigote-like forms, showing selectivity index (SI) of 25.1, 18.2 and 22.9, respectively, when 3s was used against promastigotes, and of 45.2, 7.5 and 15.0, respectively, against amastigote-like stage. Using the compound 3t, SI values were 45.2, 53.0 and 80.0, respectively, against promastigotes, and of 35.9, 46.0 and 58.4, respectively, against amastigote-like forms. Amphotericin B (AmpB) showed SI values of 5.0, 7.5 and 15.0, respectively, against promastigotes, and of 3.8, 5.0 and 7.5, respectively, against amastigote-like stage. The treatment of infected macrophages and inhibition of the infection upon pre-incubation with the molecules showed that they were effective in reducing the infection degree and inhibiting the infection in pre-incubated parasites, respectively, as compared to data obtained using AmpB. The mechanism of action of 3s and 3t was evaluated in L. infantum, revealing that both 3s and 3t altered the parasite mitochondrial membrane potential leading to reactive oxygen species production, increase in lipid corps and changes in the cell cycle, causing the parasite' death. A preliminary assay using the cell culture supernatant from treated and infected macrophages showed that 3s and 3t induced higher IL-12 and lower IL-10 values; suggesting the development of an in vitro Th1-type response in the treated cells. In this context, data indicated that 3s and 3t could be considered therapeutic agents to be tested in future studies against leishmaniasis.

Mycobacterium abscessus subsp. massiliense expressing bacterioferritin have improved resistance to stressful conditions

AIMS

The importance of bacterioferritin in the virulence and pathogenicity of the genus Mycobacterium is still unclear. The aim of this study was to analyse if the expression of a recombinant bacterioferritin from M. tuberculosis (Mtb) by Mycma could improve the capacity of this bacillus to resist the host defence mechanisms.

METHODS AND RESULTS

Recombinant Mycma, expressing bacterioferritin (Rv1876) from Mtb, was developed by transformation with pMIP12_Rv1876. To determine bacterioferritin influence on Mycma physiology and virulence, the mycobacteria growth was analysed in vitro and in vivo. It was observed that the expression of bacterioferritin improved the growth rate of recombinant Mycma_BfrA under iron excess and oxidative stress, as compared to the wild type. Furthermore, in the murine model of infection, it was observed that Mycma_BfrA-infected mice had higher bacillary load and a more pronounced lesion in the lungs when compared with the wild type.

CONCLUSION

This study showed that bacterioferritin confers additional resistance to stress conditions, resulting in increased pathogenicity of Mycma during mice infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides new insights about the importance of bacterioferritin in the virulence and pathogenicity of the Mycobacterium genus.

Gene polymorphism and plasma levels of miR-155 in diabetic retinopathy

Circulating microRNA-155 (miR-155) is associated with type 2 diabetes mellitus (T2DM) and the rs767649 polymorphism in the pre-MIR155 gene is associated with miR-155 expression. However, their relationship with diabetic retinopathy (DR) is still unknown. Therefore, the aim of this case-control study was to test the hypothesis that the rs767649 polymorphism in the pre-MIR155 gene is associated with DR in South Brazilians with T2DM. We also evaluated the association of plasma levels of miR-155 with DR and the rs767649 polymorphism in a subgroup of subjects. The rs767649 polymorphism was genotyped in 139 blood donors and 546 T2DM patients (244 had no DR, 161 had non-proliferative DR and 141 had proliferative DR). miR-155 expression was quantified in 20 blood donors and 60 T2DM patients (20 from each group). Among T2DM patients, the carriership of the A allele and the A allele were more frequent in subjects with DR than in those without it (P < 0.05), and the A allele was independently associated with an increased risk of DR (adjusted OR = 2.12, 95% CI = 1.12-4.01). The plasma levels of miR-155 were lower in T2DM patients than in blood donors (P < 0.001). However, the miR-155 levels did not differ according to the presence and severity of DR or according to rs767649 genotypes among T2DM patients. These findings support that the rs767649 polymorphism in the pre-MIR155 gene is associated with DR in T2DM and that the miR-155 plasma levels might be associated with T2DM. Additional studies are needed to further investigate their clinical significance in DR and T2DM.

Attenuation of vagal modulation with aging: Univariate and bivariate analysis of HRV

The aging process leads to diverse changes in the human organism, including in autonomic system modulation. In this study, we calculated indices of HRV in frequency (power spectral density, PSD) and time (the impulse response (IR) method) domains, using data from healthy young and elderly volunteers (Fantasia database from Physionet). The results obtained showed that aging leads to an attenuation of vagal modulation of elderly individuals when compared to young volunteers.

Marine reservoir effect on the Southeastern coast of Brazil: results from the Tarioba shellmound paired samples

On the Southeastern coast of Brazil the presence of many archaeological shellmounds offers a great potential for studying the radiocarbon marine reservoir effect (MRE). However, very few such studies are available for this region. These archaeological settlements, mostly dating from 5 to 2 kyr cal BP, include both terrestrial and marine remains in good stratigraphic context and secure association, enabling the comparison of different carbon reservoirs. In a previous study the chronology of the Sambaqui da Tarioba, located in Rio de Janeiro state, Brazil, was established based on marine mollusc shells and charcoal samples from hearths, from several layers in two excavated sectors. We now compare the different materials with the aim of studying the MRE in this region. Calibration was performed with Oxford software OxCal v4.2.3 using the marine curve Marine13 with an undetermined offset to account for local corrections for shell samples, and the atmospheric curve SHCal13 for charcoal samples. The distribution of results considering a phase model indicates a ΔR value of -127 ± 67 (14)C yr in the 1 sigma range and the multi-paired approach leads to a mean value of -110 ± 94 (14)C yr.

The diverse pharmacology and medicinal chemistry of phosphoramidates – a review

Promising examples of the phosphoramidates, which possess antiviral, antitumor, antibacterial, antimalarial and anti-protozoal as well as enzyme inhibitor activity are reviewed.

Kaurene diterpene induces apoptosis in U87 human malignant glioblastoma cells by suppression of anti-apoptotic signals and activation of cysteine proteases

Gliomas are the most common and malignant primary brain tumors in humans. Studies have shown that classes of kaurene diterpene have anti-tumor activity related to their ability to induce apoptosis. We investigated the response of the human glioblastoma cell line U87 to treatment with ent-kaur-16-en-19-oic acid (kaurenoic acid, KA). We analyzed cell survival and the induction of apoptosis using flow cytometry and annexin V staining. Additionally, the expression of anti-apoptotic (c-FLIP and miR-21) and apoptotic (Fas, caspase-3 and caspase-8) genes was analyzed by relative quantification (real-time PCR) of mRNA levels in U87 cells that were either untreated or treated with KA (30, 50, or 70 µM) for 24, 48, and 72 h. U87 cells treated with KA demonstrated reduced viability, and an increase in annexin V- and annexin V/PI-positive cells was observed. The percentage of apoptotic cells was 9% for control cells, 26% for cells submitted to 48 h of treatment with 50 µM KA, and 31% for cells submitted to 48 h of treatment with 70 µM KA. Similarly, in U87 cells treated with KA for 48 h, we observed an increase in the expression of apoptotic genes (caspase-8, -3) and a decrease in the expression of anti-apoptotic genes (miR-21 and c-FLIP). KA possesses several interesting properties and induces apoptosis through a unique mechanism. Further experiments will be necessary to determine if KA may be used as a lead compound for the development of new chemotherapeutic drugs for the treatment of primary brain tumors.

New cytogenetic aberrations found in a case of aggressive retinoblastoma

We describe a case of retinoblastoma with an atypical presentation and previously unreported cytogenetic aberrations. A 19-month-old girl with left intraocular retinoblastoma was treated with enucleation and chemotherapy. The disease showed aggressive evolution within a short period between diagnosis and relapse. Eight months after diagnosis, a new large tumor was present in the orbit of the right eye, with diffuse bone pain, pancytopenia and diffuse infiltration into the bone marrow and the central nervous system. The child did not respond to treatment and died. Cytogenetic studies made with G-banding, FISH and SKY analysis showed chromosomal aberrations commonly associated with retinoblastoma, including del(13q), i(6p), +1, and monosomy 16, along with others that had not been reported previously, including dup(5q), dic(15;22) and add(14q). The new chromosomal aberrations may be related to the aggressiveness of the disease in this case.

Autonomic and metabolic effects of OSA in childhood obesity

This study investigates the effects of exposure to intermittent hypoxia on cardiovascular autonomic control and metabolic function in obese children with obstructive sleep apnea (OSA). Each subject underwent: (1) a polysomnography; (2) morning fasting blood samples and a subsequent FSIVGTT; (3) noninvasive measurement of respiration, arterial blood pressure, and heart rate during supine and standing postures. Assessment of adiposity was performed using a DEXA scan. From these measurements, we deduced the pertinent sleep parameters, Bergman minimal model parameters and the parameters characterizing a minimal model of cardiovascular variability. Results suggest that intermittent hypoxia in OSA contributes independently to insulin resistance and autonomic dysfunction in overweight children.

Prenatal diagnosis of a partial trisomy 13q (q14-->qter): phenotype, cytogenetics and molecular characterization by spectral karyotyping and array comparative genomic hybridization

Partial trisomy 13q is an uncommon chromosomal abnormality with variable phenotypic expression. We report prenatal diagnosis of partial trisomy 13q in a fetus with partial agenesis of the cerebellar vermis, partial agenesis of the corpus callosum, hydrops and polyhydramnios. G-banding karyotyping, spectral karyotyping and array comparative genomic hybridization (aCGH) analysis of fetal blood were performed. Cytogenetic analysis of fetal blood displayed 46,XX,add(4)(q28). The parental karyotypes were normal. A girl was delivered at 34 weeks gestation; she died within 2 h. Autopsy confirmed all the prenatal findings and also showed agenesis of the diaphragm. Spectral karyotyping identified the additional material's origin as chromosome 13. aCGH was carried out and showed amplification of distal regions of the long arm of chromosome 13 from region 13q14 to qter. This is the first report of a fetus with molecular characterization of a partial trisomy 13q (q14-->qter), present as a de novo unbalanced translocation at chromosome 4q. This case demonstrates the usefulness of molecular characterization of malformed fetuses for prenatal diagnosis and counseling.

Digestion, Absorption and Tissue Distribution of Ovalbumin and Palmitoyl-ovalbumin: Impact on Immune Responses Triggered by Orally Administered Antigens

Previous work in this laboratory has demonstrated that ovalbumin coupled to palmitoyl residues (palmitoyl-Ova) does not induce oral tolerance. The present study sought to determine whether this coupling affects digestion, absorption and transfer of antigen. Ova and palmitoyl-Ova were shown to be digested differently in vitro by proteolytic enzymes and presented different tissue distribution kinetics after being labelled with (99m)technetium and orally administered to animals. Palmitoyl-Ova remained longer in the stomach, while native Ova was quickly transferred to the gut and other organs. After 3 h, higher levels of palmitoyl-Ova were found in the blood, Peyer's patches, mesenteric lymph nodes, liver and, especially, the spleen, which appears to be essential for immunization with palmitoyl-Ova. In fact, splenectomized mice treated orally with palmitoyl-Ova became tolerant, while tolerance to Ova was not affected. Thus, palmitoyl coupling was demonstrated to affect antigen digestion, absorption and transport. This is the first time that the spleen has been shown to be required for oral immunization with palmitoyl-Ova.

Neurofibromatosis type I with periodontal manifestation. A case report and literature review

The term neurofibromatosis (NF) is used for a group of genetic disorders that primarily affect the cell growth of neural tissues. Neurofibromatosis type 1 (NF1), also known as von Recklinghausen's disease, is the most common type of NF and accounts for about 90% of all cases. It is one of the most frequent human genetic diseases, with a prevalence of one case in 3,000 births. The expressivity of NF1 is extremely variable, with manifestations ranging from mild lesions to several complications and functional impairment. Oral manifestations can be found in almost 72% of NF1 patients. A case of a NF1 patient with a gingival neurofibroma in the attached gingiva of the lingual aspect of the lower central incisors is presented. The lesion was nodular, with sessile base, non-ulcerated, non-painful, with normal colour and measured 1 cm in diameter. An excisional biopsy of the oral lesion was performed. Histopathological and immunohistochemical analysis confirmed the clinical hypothesis of neurofibroma. Because NF1 is one of the most common genetic diseases and oral manifestations are very common, dentists should be aware of the characteristics of this disease.

Covalent coupling of palmitate to ovalbumin inhibits and blocks the induction of oral tolerance

Oral tolerance is a phenomenon that may occur in animals exposed to soluble antigens for the first time by the oral route. In the present study, we show that oral tolerance against ovalbumin (Ova) can be obtained after intragastric administration of the antigen in the presence of free residues of palmitate. On the other hand, oral tolerance induction is blocked when the residues of palmitate are covalently bound to the antigen (Ova-palmitate conjugates). We have also noticed that oral administration of Ova-palmitate conjugates can boost and/or prime experimental animals for Ova-specific cellular and humoral systemic immune responses. Oral treatment with the conjugates also induces the production of local secretory immunoglobulin A (IgA) as measured in intestinal washes. Furthermore, Ova-palmitate given orally can inhibit oral tolerance induction by naïve Ova.

Histoplasmosis in Rio Grande do Sul, Brazil: a 21-year experience

Of 156 cases of histoplasmosis observed in the State of Rio Grande do Sul (Brazil), during a 21-year period (1978-1999) 137 were included in this study. Sixty-seven per cent of the patients had hematogeneous disseminated histoplasmosis, 24% had a self-limited syndrome (acute pulmonary histoplasmosis, histoplasmoma or primary pulmonary lymph node complex), and 9 per cent had chronic pulmonary histoplasmosis. Clinical, mycological, and epidemiological data were reviewed and commented.

Mycetoma caused by Exophiala jeanselmei. Report of a case successfully treated with itraconazole and review of the literature

We report a case of black grain mycetoma in a 74-years-old man who presented with a 50-yr. history of sinus-tract formation in the right foot. This is the first case of an Exophiala jeanselmeimycetoma successfully treated with itraconazole. In addition a review of the literature on this subject was done.

Coupling of palmitate to ovalbumin inhibits the induction of oral tolerance

Oral tolerance is a phenomenon that may occur in animals exposed to protein antigens for the first time by the oral route. They become unable to produce immune responses at the levels normally observed when they are immunized parenterally with antigen in the presence of adjuvants. Lipids have been used as adjuvants for both parenteral and oral immunization. In the present study we coupled ovalbumin with palmitate residues by incubating the protein with the N-hydroxysuccinimide palmitate ester and tested the preparation for its ability to induce oral tolerance. This was performed by giving 20 mg of antigen to mice by the oral route 7 days prior to parenteral immunization in the presence of A1(OH)3. Mice were bled one week after receiving a booster that was given 2 weeks after primary immunization. Specific antibodies were detected by ELISA. Despite the fact that the conjugates are as immunogenic as the unmodified protein when parenterally injected in mice, they failed to induce oral tolerance. This discrepancy could be explained by differences in the intestinal absorption of the two forms of the antigen. In fact, when compared to the non-conjugated ovalbumin, a fast and high absorption of the lipid-conjugated form of ovalbumin was observed by "sandwich" ELISA.