The Effects of Testosterone Therapy Combined with Swimming Exercise on Adipose Tissue and Biochemical Parameters in Male Obese Wistar Rats.

Context: Exercise and anabolic steroids are anticipated to promote fat mass reduction and so to decrease the number of comorbidities related to excessive weight. Objective: The aim of this study was to verify the influence of aerobic exercise and the use of steroids on the accumulation of adipose tissue and on the biochemical limitations of Wistar rats nourished by a hypercaloric diet. Methods: Forty, young male Wistar rats were split into four groups: obese control (n=10), obese under treatment (n=10), obese under aerobic exercise (n=10) and obese under aerobic exercise and treatment (n=10). All animals were fed with a hypercaloric diet and animals under treatment received intramuscular testosterone. Body (weight and visceral fat) and blood (lipidogram, glucose, and liver enzymes) parameters were assessed. Results: The group treated with aerobic exercise and testosterone revealed a reduction in body weight and visceral, perirenal, retroperitoneal and epididymal fats, accompanied by the blood levels of glucose, lactate, LDL-cholesterol, HDL-cholesterol, and lactate dehydrogenase; following high-intensity physical activity. Conclusion: The results support the theory that the combination of steroids and physical activity reduces the side-effects of androgenic-anabolic hormones and conveys benefits to some constraints.

Double membrane based on lidocaine-coated polymyxin-alginate nanoparticles for wound healing: In vitro characterization and in vivo tissue repair.

The aim of this study was to develop and characterize a double layer biomembrane for dual drug delivery to be used for the treatment of wounds. The membrane was composed of chitosan, hydroxypropyl methylcellulose and lidocaine chloride (anesthetic drug) in the first layer, and of sodium alginate-polymyxin B sulphate (antibiotic) nanoparticles as the second layer. A product with excellent thickness (0.01-0.02 mm), adequate mechanical properties with respect to elasticity, stiffness, tension, and compatible pH for lesion application has been successfully obtained. The incorporation of the drugs was confirmed analysing the membrane cross-sections by scanning electron microscopy. A strong interaction between the drugs and the functional groups of respective polymers was confirmed by Fourier-Transform Infrared Spectroscopy, thermal analysis and X-ray diffraction. Microbiological assays showed a high antimicrobial activity when polymyxin B was present to act against the Staphylococcus aureus and Pseudomonas aeruginosa strains. Low cytotoxicity observed in a cell viability colorimetric assay and SEM analysis suggest biocompatibility between the developed biomembrane and the cell culture. The in vivo assay allowed visualizing the healing potential by calculating the wound retraction index and by histological analysis. Our results confirm the effectiveness of the developed innovative biomaterial for tissue repair and regeneration in an animal model.

Silver Nanoparticles-Composing Alginate/Gelatine Hydrogel Improves Wound Healing In Vivo.

Polymer hydrogels have been suggested as dressing materials for the treatment of cutaneous wounds and tissue revitalization. In this work, we report the development of a hydrogel composed of natural polymers (sodium alginate and gelatin) and silver nanoparticles (AgNPs) with recognized antimicrobial activity for healing cutaneous lesions. For the development of the hydrogel, different ratios of sodium alginate and gelatin have been tested, while different concentrations of AgNO3 precursor (1.0, 2.0, and 4.0 mM) were assayed for the production of AgNPs. The obtained AgNPs exhibited a characteristic peak between 430-450 nm in the ultraviolet-visible (UV-Vis) spectrum suggesting a spheroidal form, which was confirmed by Transmission Electron Microscopy (TEM). Fourier Transform Infra-red (FT-IR) analysis suggested the formation of strong intermolecular interactions as hydrogen bonds and electrostatic attractions between polymers, showing bands at 2920, 2852, 1500, and 1640 cm-1. Significant bactericidal activity was observed for the hydrogel, with a Minimum Inhibitory Concentration (MIC) of 0.50 µg/mL against Pseudomonas aeruginosa and 53.0 µg/mL against Staphylococcus aureus. AgNPs were shown to be non-cytotoxic against fibroblast cells. The in vivo studies in female Wister rats confirmed the capacity of the AgNP-loaded hydrogels to reduce the wound size compared to uncoated injuries promoting histological changes in the healing tissue over the time course of wound healing, as in earlier development and maturation of granulation tissue. The developed hydrogel with AgNPs has healing potential for clinical applications.

In Vitro and In Vivo Studies of the Trypanocidal Effect of Novel Quinolines.

Therapies for human African trypanosomiasis and Chagas disease, caused by Trypanosoma brucei and Trypanosoma cruzi, respectively, are limited, providing minimal therapeutic options for the millions of individuals living in very poor communities. Here the effects of 10 novel quinolines are evaluated in silico and by phenotypic studies using in vitro and in vivo models. Absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties revealed that most molecules did not infringe on Lipinski's rules, which is a prediction of good oral absorption. These quinolines showed high probabilities of Caco2 permeability and human intestinal absorption and low probabilities of mutagenicity and of hERG1 inhibition. In vitro screens against bloodstream forms of T. cruzi demonstrated that all quinolines were more active than the reference drug (benznidazole [Bz]), except for DB2171 and DB2192, with five (DB2187, DB2131, DB2186, DB2191, and DB2217) displaying 50% effective concentrations (EC50s) of <3 µM (4-fold lower than that of Bz). Nine quinolines were more effective than Bz (2.7 µM) against amastigotes, showing EC50s ranging from 0.6 to 0.1 µM. All quinolines were also highly active in vitro against African trypanosomes, showing EC50s of ≤0.25 µM. The most potent and highly selective candidates for each parasite species were tested in in vivo models. Results for DB2186 were promising in mice with T. cruzi and T. brucei infections, reaching a 70% reduction of the parasitemia load for T. cruzi, and it cured 2 out of 4 mice infected with T. brucei DB2217 was also active in vivo and cured all 4 mice (100% cure rate) with T. brucei infection.

Drug repurposing strategy against Trypanosoma cruzi infection: In vitro and in vivo assessment of the activity of metronidazole in mono- and combined therapy.

Metronidazole (Mtz) is a commercial broad-spectrum nitroimidazolic derivative with relevant antimicrobial activity and relative safety profile. Therefore, it is fair to consider Mtz a candidate for drug repurposing for other neglected conditions such as Chagas disease (CD), a parasitic pathology caused by Trypanosoma cruzi. CD is treated only with benznidazole (Bz) and nifurtimox, both introduced in clinics decades ago despite important limitations, including low efficacy on the later disease stage (chronic form) and severe side effects. New cheap and fast alternative treatments for CD are needed, thus the repurposing of Mtz was assessed in vitro and in vivo in mono- and combined therapy. In vitro assays demonstrated EC50>200µM for Mtz, while for Bz the values ranged from 2.51µM (intracellular forms) to 11.5µM (bloodstream trypomastigotes). When both drugs were combined in fixed-ratio proportions, Mtz promoted Bz potency (lower EC50 values). In vivo toxicity assays for Mtz in mice showed no adverse effects neither histopathological alterations up to 2000mg/kg. Regarding experimental T. cruzi infection, Bz 100mg/kg suppressed parasitemia while Mtz (up to 1000mg/kg) in monotherapy did not, but prolonged animal survival at 250 and 500 regimen doses. The combination of both drugs (Bz 10+Mtz 250) prevented mortality (70%) besides protected against electric cardiac alterations triggered by the parasite infection. Although not able to reduce parasite load, the combination therapy prevented animal mortality; this was possibly due to a protection of the electric cardiac physiology that is normally altered in experimental infection of T. cruzi. It also suggested that the interaction with Mtz could have improved the pharmacokinetics of Bz. Our study emphasizes the importance of drug repurposing and combined therapy for CD to contribute to alternative therapies for this neglected and silent pathology.

Antitrypanosomal Activity of Sterol 14α-Demethylase (CYP51) Inhibitors VNI and VFV in the Swiss Mouse Models of Chagas Disease Induced by the Trypanosoma cruzi Y Strain.

Chagas disease is a life-threatening infection caused by a variety of genetically diverse strains of the protozoan parasite Trypanosoma cruzi The current treatment (benznidazole and nifurtimox) is unsatisfactory, and potential alternatives include inhibitors of sterol 14α-demethylase (CYP51), the cytochrome P450 enzyme essential for the biosynthesis of sterols in eukaryotes and the major target of clinical and agricultural antifungals. Here we performed a comparative investigation of two protozoon-specific CYP51 inhibitors, VNI and its CYP51 structure-based derivative VFV, in the murine models of infection caused by the Y strain of T. cruzi The effects of different treatment regimens and drug delivery vehicles were evaluated in animals of both genders, with benznidazole serving as the reference drug. Regardless of the treatment scheme or delivery vehicle, VFV was more potent in both genders, causing a >99.7% peak parasitemia reduction, while the VNI values varied from 91 to 100%. Treatments with VNI and VFV resulted in 100% animal survival and 0% natural relapse after the end of therapy, though, except for the 120-day treatment schemes with VFV, relapses after three cycles of immunosuppression were observed in each animal group, and quantitative PCR analysis revealed a very light parasite load in the blood samples (sometimes below or near the detection limit, which was 1.5 parasite equivalents/ml). Our studies support further investigations of this class of compounds, including their testing against other T. cruzi strains and in combination with other drugs.

In Vitro and In Vivo Trypanosomicidal Action of Novel Arylimidamides against Trypanosoma cruzi.

Arylimidamides (AIAs) have been shown to have considerable biological activity against intracellular pathogens, includingTrypanosoma cruzi, which causes Chagas disease. In the present study, the activities of 12 novel bis-AIAs and 2 mono-AIAs against different strains ofT. cruziin vitroandin vivowere analyzed. The most active wasm-terphenyl bis-AIA (35DAP073), which had a 50% effective concentration (EC50) of 0.5 µM for trypomastigotes (Y strain), which made it 26-fold more effective than benznidazole (Bz; 13 µM). It was also active against the Colombiana strain (EC50= 3.8 µM). Analysis of the activity against intracellular forms of the Tulahuen strain showed that this bis-AIA (EC50= 0.04 µM) was about 100-fold more active than Bz (2 µM). The trypanocidal effect was dissociated from the ability to trigger intracellular lipid bodies within host cells, detected by oil red labeling. Both an active compound (35DAP073) and an inactive compound (26SMB060) displayed similar activation profiles. Due to their high selectivity indexes, two AIAs (35DAP073 and 35DAP081) were moved toin vivostudies, but because of the results of acute toxicity assays, 35DAP081 was excluded from the subsequent tests. The findings obtained with 35DAP073 treatment of infections caused by the Y strain revealed that 2 days of therapy induced a dose-dependent action, leading to 96 to 46% reductions in the level of parasitemia. However, the administration of 10 daily doses in animals infected with the Colombiana strain resulted in toxicity, preventing longer periods of treatment. The activity of the combination of 0.5 mg/kg of body weight/day 35DAP073 with 100 mg/kg/day Bz for 10 consecutive days was then assayed. Treatment with the combination resulted in the suppression of parasitemia, the elimination of neurological toxic effects, and survival of 100% of the animals. Quantitative PCR showed a considerable reduction in the parasite load (60%) compared to that achieved with Bz or the amidine alone. Our results support further investigations of this class with the aim of developing novel alternatives for the treatment of Chagas disease.

Different Therapeutic Outcomes of Benznidazole and VNI Treatments in Different Genders in Mouse Experimental Models of Trypanosoma cruzi Infection.

The lack of translation between preclinical assays and clinical trials for novel therapies for Chagas disease (CD) indicates a need for more feasible and standardized protocols and experimental models. Here, we investigated the effects of treatment with benznidazole (Bz) and with the potent experimental T. cruzi CYP51 inhibitor VNI in mouse models of Chagas disease by using different animal genders and parasite strains and employing distinct types of therapeutic schemes. Our findings confirm that female mice are less vulnerable to the infection than males, show that male models are less susceptible to treatment with both Bz and VNI, and thus suggest that male models are much more suitable for selection of the most promising antichagasic agents. Additionally, we have found that preventive protocols (compound given at 1 dpi) result in higher treatment success rates, which also should be avoided during advanced steps of in vivo trials of novel anti-T. cruzi drug candidates. Another consideration is the relevance of immunosuppression methods in order to verify the therapeutic profile of novel compounds, besides the usefulness of molecular diagnostic tools (quantitative PCR) to ascertain compound efficacy in experimental animals. Our study aims to contribute to the development of more reliable methods and decision gates for in vivo assays of novel antiparasitic compounds in order to move them from preclinical to clinical trials for CD.

In vitro and in vivo studies of the biological activity of novel arylimidamides against Trypanosoma cruzi.

Fifteen novel arylimidamides (AIAs) (6 bis-amidino and 9 mono-amidino analogues) were assayed against Trypanosoma cruzi in vitro and in vivo. All the bis-AIAs were more effective than the mono-AIAs, and two analogues, DB1967 and DB1989, were further evaluated in vivo. Although both of them reduced parasitemia, protection against mortality was not achieved. Our results show that the number of amidino-terminal units affects the efficacy of arylimidamides against T. cruzi.

hsp65 PCR-restriction enzyme analysis (PRA) for identification of mycobacteria in the clinical laboratory.

More than 70 species of mycobacteria have been defined, and some can cause disease in humans, especially in immunocompromised patients. Species identification in most clinical laboratories is based on phenotypic characteristics and biochemical tests and final results are obtained only after two to four weeks. Quick identification methods, by reducing time for diagnosis, could expedite institution of specific treatment, increasing chances of success. PCR restriction-enzyme analysis (PRA) of the hsp65 gene was used as a rapid method for identification of 103 clinical isolates. Band patterns were interpreted by comparison with published tables and patterns available at an Internet site (http://www.hospvd.ch:8005). Concordant results of PRA and biochemical identification were obtained in 76 out of 83 isolates (91.5%). Results from 20 isolates could not be compared due to inconclusive PRA or biochemical identification. The results of this work showed that PRA could improve identification of mycobacteria in a routine setting because it is accurate, fast, and cheaper than conventional phenotypic identification.

Reduced sensory neuron regeneration by C57BL/6J mice.

The tube repair method was used to study peripheral nerve regeneration in five different inbred mouse strains. The sciatic nerve of male adult mice of the C57BL/6J, DBA/1J, C3H/HeJ, BALB/cJ and A/J strains (N = 3) was cut and both proximal and distal nerve stumps were inserted into a polyethylene tube leaving a 4-mm nerve gap. After 6 weeks the tubes containing the regenerated nerve cables were processed for total myelinated axon counts. C57BL/6J mice regenerated significantly fewer myelinated axons (1024 +/- 178, mean +/- SEM) compared to the BALB/cJ (1618 +/- 64), A/J (1788 +/- 95), DBA/1J (2168 +/- 296) or C3H/HeJ (3468 +/- 36) strains. Horseradish peroxidase was applied 3 mm distal to the tube 4 and 40 weeks after tube implantation to further characterize the reduced regenerative response of C57BL/6J mice. Labeled sensory and somatic motor neurons were counted in the spinal cord and L4,5,6 dorsal root ganglia (DRG), respectively. Sciatic nerves from four intact C57BL/6J mice were processed in the same fashion and used as normal controls. No significant difference in the number of motor neurons was detected between the experimental (4 weeks = 663 +/- 74; 40 weeks = 770 +/- 35) and control non-operated (844 +/- 13) animals. However, there were fewer labeled neurons in the DRG of the operated group (4 weeks = 1163 +/- 167; 40 weeks = 2574 +/- 104) compared to the control group (4211 +/- 96). These results indicate that sensory neurons are responsible for the diminished regenerative response in C57BL/6J mice after peripheral nerve transection.(ABSTRACT TRUNCATED AT 250 WORDS)

Local addition of monosialoganglioside GM1 stimulates peripheral axon regeneration in vivo.

Tubulization repair technique is a useful model to study peripheral nerve regeneration by offering quantifiable parameters to assess the possible effect of exogenously applied substances on nerve repair. In the present study we demonstrated that locally administered GM1 inside a tubular prosthesis at the time of implantation can significantly improve the repair process. The sciatic nerve of 8 male C57BL/6J mice, approximately 3 months old at the time of surgery and divided into two groups of 4 animals each, was transected and the proximal and distal nerve stumps were sutured into a polyethylene tube (PT), 0.76 mm internal diameter (ID), to bridge a nerve gap of 4 mm. The tubes contained 2 microliters of collagen type I (2.4 mg/ml) alone or in combination (1:1 volume ratio) with monosialoganglioside GM1 (10 mg/ml in the final solution). Four additional animals received a PT with 1.14 mm ID filled with 5.5 microliters of collagen/GM1 (at the same ratio and final concentration as above). After 6 weeks the PT with the regenerating nerve cables were processed for total myelinated axon counts with a computer-controlled system. GM1 significantly increased peripheral axon regeneration (3427 +/- 64 myelinated axons for the 0.76-mm PT and 3623 +/- 270 for the 1.14-mm PT, mean +/- SEM) compared to the group receiving collagen alone (2516 +/- 156) and this effect did not depend on tube diameter. This action is possibly due to a stimulating effect of GM1 on neurite outgrowth and sprouting.

Jejunal biopsy in HIV-infected patients.

Forty-nine HIV-infected patients were submitted to peroral jejunal biopsy in order to evaluate the presence of microorganisms and the histomorphometric aspects of the enteric mucosa with subsequent correlation of these findings to the appropriate clinical stage of the disease. Thirty-seven patients fulfilled the CDC criteria for AIDS, of whom 23 presented with diarrhea. Of the 12 patients who had not yet been given an AIDS diagnosis. 3 had persistent generalized lymphadenopathy and 9 were asymptomatic carriers. Flat mucosa was observed in two patients (8.7%) with diarrhea and coccidea. Subtotal villous atrophy and severe lamina propria (LP) mononuclear infiltrate (13%) were found only in patients with diarrhea. Moderate to severe histologic changes were more frequently observed in this group, not always related to the presence of microorganisms. Crypt hyperregeneration was a constant finding. Intraepithelial lymphocyte (IEL) count was decreased in patients with diarrhea. Specific infectious agents were unexpectedly rare for the tropical developing country population studied. The organism most commonly associated with diarrhea was Cryptosporidium sp. (21.7%). The etiology of diarrhea in a significant number of patients remains unclear.

Local administration of interleukin-1 increases sensory neuron regeneration in vivo.

The proximal and distal stumps of severed mouse sciatic nerves were inserted into opposite ends of polyethylene tubes. The tubes were implanted either empty or filled with collagen alone or in combination with interleukin-1 (IL1). Six weeks later, neurons in the L3-L5 dorsal root ganglia were back-filled with HRP. The number of HRP reactive sensory neurons detected in the IL1-treated animals was significantly greater than that seen in the other experimental groups. Thus, exogenous IL1 may partially mimic the effects obtained with in vivo administration of nerve growth factor in protecting sensory neurons from lesion-induced death.

Exogenous ganglioside stimulation of axonal regeneration after nerve transection and entubulation repair.

Adult male mice received sciatic nerve transection at the midthigh level and both nerve stumps were sutured into a polyethylene tube (PT) to bridge a nerve gap of 4 mm. The tubes were implanted either empty, or filled with collagen alone or in combination with gangliosides (GM1, GD1a, GD1b and GT1b). Following a survival time of 6 weeks, the PT with the regenerating nerve cables were processed for plastic embedding, and morphometric measurements were made on myelinated and unmyelinated axons. The data suggest that local application of exogenous gangliosides causes a stimulation of axonal sprouting in vivo with no effect on the rate of axonal maturation.

Addition of nerve growth factor to the interior of a tubular prosthesis increases sensory neuron regeneration in vivo.

The sciatic nerve of adult mice was transected and the proximal and distal nerve stumps were sutured into a polyethylene tube. The tubes were implanted either empty, or the lumen was filled with pure collagen or a mixture of collagen/nerve growth factor (NGF). Six weeks later, cells in the L3-L5 dorsal root ganglia (DRG) were retrogradely filled with horseradish peroxidase (HRP). The data demonstrate that the addition of NGF to the interior of the tubular prosthesis can significantly increase the regeneration rate of sensory neurons.

Entubulation repair with protein additives increases the maximum nerve gap distance successfully bridged with tubular prostheses.

The major objective of the experiments reported in this paper was to test the hypothesis that the maximum distance that peripheral nervous system (PNS) axons can regenerate through a tubular prosthesis may be increased by specific modifications to the internal environment of the prosthesis. The sciatic nerve of adult male rats was transected and proximal and distal nerve stumps were sutured into a silicone tube 20-25 mm in length. The silicone tubes were implanted empty, or the lumen was filled with collagen or a laminin-containing gel. Following 4-16 weeks survival time animals were sacrificed and the contents of the silicone tubes were processed for histological identification of myelinated and unmyelinated axons. All of the tubes with additives, but one of the initially empty tubes, displayed a regenerated nerve cable within the tube. Retrograde labeling studies were carried out to prove that some of the axons present in the regenerated nerve cables arose from primary motor and sensory neurons. These results show that specific modifications to the microenvironment of regenerating PNS axons can affect the success or failure of tubular prostheses for nerve repair.

Light and dark cells in the lumbar sensory ganglia of pre and post-hatching domestic fowl.

Clear and dark satellite cell classes were identified by electron microscopy in the lumbar sensory ganglia of domestic fowl in 8 pre and 4 post-hatching stages of development. Some cytologic differences found between the two classes relating to the rough-endoplasmic reticulum, ribosomes, Golgi apparatus and junctional complexes suggest the existence of distinct functional features for both types of satellite cells.