Involvement of nitric oxide in the neurobiology of fear-like behavior.

Fear is an emotional reaction that arises in dangerous situations, inducing the adaptation to an existing condition. This behavior was conserved in all vertebrates throughout evolution and is observed in mammals, birds, fish, amphibians, and reptiles. The neurocircuitry of fear involves areas of the limbic system, cortical regions, midbrain, and brainstem. These areas communicate with each other so that there is an expression of fear and memory formation to deal with the same situation at another time. The effect of nitric oxide (NO) on fear modulation has been explored. NO is a gaseous compound that easily diffuses through the cell membrane and is produced through the oxidation reaction of l-Arginine to l-citrulline catalyzed by nitric oxide synthase (NOS). Activating the intracellular NO receptor (soluble guanylyl cyclase enzyme - sGC) triggers an enzymatic cascade that can culminate in plastic events in the neuron. NOS inhibitors induce anxiolytic-like responses in fear modulation, whereas NO donors promote fear- and anxiety-like behaviors. This review describes the neurobiology of fear in mammals and non-mammals, how NO is produced in the central nervous system, and how NO acts in fear-like behavior.

COVID-19-associated mucormycosis: A review of an emergent epidemic fungal infection in the era of COVID-19 pandemic.

At a time when the COVID-19's second wave is still picking up in countries like India, a number of reports describe the potential association with a rise in the number of cases of mucormycosis, commonly known as the black fungus. This fungal infection has been around for centuries and affects those people whose immunity has been compromised due to severe health conditions. In this article, we provide a detailed overview of mucormycosis and discuss how COVID-19 could have caused a sudden spike in an otherwise rare disease in countries like India. The article discusses the various symptoms of the disease, class of people most vulnerable to this infection, preventive measures to avoid the disease, and various treatments that exist in clinical practice and research to manage the disease.

HIV-1 Gag mutations alone are sufficient to reduce darunavir susceptibility during virological failure to boosted PI therapy.

BACKGROUND: Virological failure (VF) to boosted PIs with a high genetic barrier is not usually linked to the development of resistance-associated mutations in the protease gene. METHODS: From a cohort of 520 HIV-infected subjects treated with lopinavir/ritonavir or darunavir/ritonavir monotherapy, we retrospectively identified nine patients with VF. We sequenced the HIV-1 Gag-protease region and generated clonal virus from plasma samples. We characterized phenotypically clonal variants in terms of replicative capacity and susceptibility to PIs. Also, we used VESPA to identify signature mutations and 3D molecular modelling information to detect conformational changes in the Gag region. RESULTS: All subjects analysed harboured Gag-associated polymorphisms in the absence of resistance mutations in the protease gene. Most Gag changes occurred outside Gag cleavage sites. VESPA analyses identified K95R and R286K (P < 0.01) as signature mutations in Gag present at VF. In one out of four patients with clonal analysis available, we identified clonal variants with high replicative capacity and 8- to 13-fold reduction in darunavir susceptibility. These clonal variants harboured K95R, R286K and additional mutations in Gag. Low susceptibility to darunavir was dependent on the Gag sequence context. All other clonal variants analysed preserved drug susceptibility and virus replicative capacity. CONCLUSIONS: Gag mutations may reduce darunavir susceptibility in the absence of protease mutations while preserving viral fitness. This effect is Gag-sequence context dependent and may occur during boosted PI failure.

Impact of intensification with raltegravir on HIV-1-infected individuals receiving monotherapy with boosted PIs.

Background: Monotherapy with ritonavir-boosted PIs (PI/r) has been used to simplify treatment of HIV-1-infected patients. In previous studies raltegravir intensification evidenced ongoing viral replication and reduced T cell activation, preferentially in subjects receiving PI-based triple ART. However, data about low-level viral replication and its consequences in patients receiving PI/r monotherapy are scarce. Methods: We evaluated the impact of 24 weeks of intensification with raltegravir on markers of viral persistence, cellular immune activation and inflammation biomarkers in 33 patients receiving maintenance PI/r monotherapy with darunavir or lopinavir boosted with ritonavir. ClinicalTrials.gov identifier: NCT01480713. Results: The addition of raltegravir to PI/r monotherapy resulted in a transient increase in 2-LTR (long-terminal repeat) circles in a significant proportion of participants, along with decreases in CD8+ T cell activation levels and a temporary increase in the expression of the exhaustion marker CTLA-4 in peripheral T lymphocytes. Intensification with raltegravir also reduced the number of samples with intermediate levels of residual viraemia (10-60 HIV-1 RNA copies/mL) compared with samples taken during PI/r monotherapy. However, there were no changes in cell-associated HIV-1 DNA in peripheral CD4+ T cells or soluble inflammatory biomarkers (CD14, IP-10, IL-6, C-reactive protein and D-dimer). Conclusions: Intensification of PI/r monotherapy with raltegravir revealed persistent low-level viral replication and reduced residual viraemia in some patients during long-term PI/r monotherapy. The concomitant change in T cell phenotype suggests an association between active viral production and T cell activation. These results contribute to understanding the lower efficacy rates of PI/r monotherapies compared with triple therapies in clinical trials.

Anatomical description of the main vessels for venipuncture in the black-striped capuchin monkey (Sapajus libidinosus, Silva Junior, 2002).

BACKGROUND: The scarcity of data on the anatomy of Sapajus libidinosus has impeded the execution for appropriate veterinary treatment. The objective of this study was to describe the main peripheral veins of the capuchin monkey, used in venipuncture and indicate the best access route for venipuncture procedures. METHODS: Ten S. libidinosus corpses were used. The face, neck, chest, and pelvic limb were dissected using surgical instruments to identify and locate surface vessels. RESULTS: The main superficial veins identified could be used for venipuncture in capuchin monkey where the external jugular, brachial, cephalic, saphenous, and femoral veins. The veins in the pelvic limb were the most suitable for this purpose, with an un anesthetized subject. CONCLUSIONS: The femoral vein was shown to be the most suitable for blood sampling and drug administration and the saphenous vein for serum therapy protocols.

The lipid-lowering effect of tenofovir/emtricitabine: a randomized, crossover, double-blind, placebo-controlled trial.

BACKGROUND: It is unknown if tenofovir disoproxil fumarate (TDF), which is often coformulated with the lipid-neutral emtricitabine (FTC), has a lipid-lowering effect. METHODS: We performed a randomized, crossover, double-blind, placebo-controlled clinical trial on human immunodeficiency virus type 1 (HIV-1)-infected subjects with HIV-1 RNA < 50 copies/mL during ≥6 months on stable darunavir/ritonavir (800/100 mg once daily) or lopinavir/ritonavir (400/100 mg twice daily) monotherapy, fasting total cholesterol (TC) ≥200 mg/dL or low-density lipoprotein cholesterol (LDL-c) ≥130 mg/dL, and no lipid-lowering drugs. In arm 1, TDF/FTC was added for 12 weeks, followed by 12 weeks of placebo (washout) and 12 additional weeks of placebo (placebo period). Subjects in arm 2 added placebo for 12 weeks (placebo period) followed by TDF/FTC for 12 weeks and placebo for 12 additional weeks (washout). The primary endpoint was change in median fasting TC levels. RESULTS: Of 46 subjects enrolled, 56% received darunavir/ritonavir and 44% lopinavir/ritonavir. Exposure to TDF/FTC reduced TC from 234 to 205 mg/dL (P < .001), LDL-c from 155 to 128 mg/dL (P < .001), and high-density lipoprotein cholesterol (HDL-c) from 50.3 to 44.5 mg/dL (P < .001). It also decreased the proportion of subjects with fasting TC ≥200 mg/dL from 86.7% to 56.8% (P = .001), and LDL-c ≥130 mg/dL from 87.8% to 43.9% (P < .001). After 12 weeks, TDF/FTC exposure was associated with lower TC and LDL-c levels than placebo (P = .001 and P = .002, respectively). The TC/HDL-c ratio and triglyceride levels did not change with TDF/FTC exposure. CONCLUSIONS: Coformulated TDF/FTC has an intrinsic lipid-lowering effect, likely attributable to TDF. CLINICAL TRIALS REGISTRATION: NCT01458977.

Monotherapy with boosted PIs as an ART simplification strategy in clinical practice.

BACKGROUND: Data on the efficacy of simplifying therapy using darunavir/ritonavir and lopinavir/ritonavir monotherapy in clinical practice remain limited. METHODS: A retrospective single-centre study including patients initiating darunavir/ritonavir or lopinavir/ritonavir monotherapy with a plasma HIV-1 viral load (pVL) <50 copies/mL and at least one subsequent follow-up visit. The primary endpoint was the percentage of patients remaining free of virological failure (VF; defined as a confirmed pVL >50 copies/mL or as any change in the regimen after a single determination with a pVL >50 copies/mL) during the follow-up. We also evaluated the percentage of patients remaining free of treatment failure (TF; defined as VF or the early discontinuation of monotherapy for any reason) and compared the effectiveness of the two regimens. Effectiveness was evaluated using cumulative survival analysis (at Weeks 48 and 96). Factors associated with VF and TF were analysed using Cox regression. RESULTS: A total of 522 patients were included (309 receiving lopinavir/ritonavir and 213 receiving darunavir/ritonavir). The median follow-up was 64.3 (30.5-143.0) weeks. The percentage of patients free of VF and TF was 94% (95% CI 91%-96%) and 79% (95% CI 75%-82%) at 48 weeks, respectively, and 86% (95% CI 81%-89%) and 62% (95% CI 57%-67%) at 96 weeks, respectively. The risk of VF was similar for the two regimens (HR=1.0, 95% CI 0.6-1.8; P=0.962). Lopinavir/ritonavir monotherapy was associated with a 1.5-fold greater risk of TF (95% CI 1.1-2.1; P=0.012) and a 2.3-fold greater risk of discontinuation of therapy due to adverse events (95% CI 1.3-3.9; P=0.003). CONCLUSIONS: The virological efficacy of darunavir/ritonavir and lopinavir/ritonavir monotherapy is high in clinical practice. Treatment discontinuation due to safety issues is more frequent with lopinavir/ritonavir.

Epidural anesthesia in capuchin monkeys (Sapajus libidinosus).

BACKGROUND: Many primates are kept in breeding for scientific or conservation purposes, but much of the clinical care is represented by trauma. To provide more effective interventions in some of these cases, the present study aimed to evaluate the technique of local anesthesia through the epidural space in capuchin monkeys (Sapajus libidinosus). METHODS: Ten animals were used, which have been deposited in the epidural space 1% lidocaine at a dose of 0.3 ml/kg over the lumbosacral joint. Heart and respiratory rates, oxygen saturation in arterial hemoglobin, blood pressure, rectal temperature, nociception, and cutaneous sensitivity were assessed before and after application. RESULTS: The technique promoted loss of sensation of the skin and muscle relaxation of the pelvic limbs, tail, and perineal region for a period of 35 minutes without any of the physiological parameters measured varies beyond normal values. CONCLUSIONS: The technique proved easy to perform, safe, and effective.

Long-term changes in bone mineral density after switching to a protease inhibitor monotherapy in HIV-infected subject.

Although some clinical trials have studied the impact of treatments on bone mineral density (BMD), scarce data are available about the impact of protease inhibitor (PI) monotherapies on BMD. The aim of this study was to evaluate changes in BMD in patients after one, two, or three years of a PI monotherapy. This study included 46 HIV-infected patients who switched from a conventional triple antiretroviral strategy to a monotherapy with lopinavir/ritonavir (LPV/r) or darunavir/ritonavir (DRV/r) for one (one-year group, n=16), two (two-year group, n=20), and three (three-year group, n=10) years. BMD was assessed by dual-energy X-ray absorptiometry (DXA). The median percentage of change in total femur BMD was 0.20% after one, 0.79% after two, and -0.31% after three years. The change in lumbar spine was -0.08%, -0.14%, and 0.50% % after the same years. No significant differences were found when patients were classified regarding the type of PI and whether or not had previously received PI or tenofovir. However, patients who interrupted tenofovir or those who started with DRV/r had a higher BMD increment. Patients who had taken non-nucleoside reverse transcriptase inhibitors previously decreased BMD when started PIs. Monotherapy treatment with ritonavir-boosted protease inhibitors (both LPV/r and DRV/r) during one, two, or three years leads to the stabilization of BMD in HIV-infected patients with long-term virological suppression. Larger studies are necessary to compare the effect of starting or withdrawing PIs on BMD.

Improved prediction of salvage antiretroviral therapy outcomes using ultrasensitive HIV-1 drug resistance testing.

BACKGROUND: The clinical relevance of ultrasensitive human immunodeficiency virus type 1 (HIV-1) genotypic resistance testing in antiretroviral treatment (ART)-experienced individuals remains unknown. METHODS: This was a retrospective, multicentre, cohort study in ART-experienced, HIV-1-infected adults who initiated salvage ART including, at least 1 ritonavir-boosted protease inhibitor, raltegravir or etravirine. Presalvage ART Sanger and 454 sequencing of plasma HIV-1 were used to generate separate genotypic sensitivity scores (GSS) using the HIVdb, ANRS, and REGA algorithms. Virological failure (VF) was defined as 2 consecutive HIV-1 RNA levels ≥200 copies/mL at least 12 weeks after salvage ART initiation, whereas subjects remained on the same ART. The ability of Sanger and 454-GSS to predict VF was assessed by receiver operating characteristic (ROC) curves and survival analyses. RESULTS: The study included 132 evaluable subjects; 28 (21%) developed VF. Using HIVdb, 454 predicted VF better than Sanger sequencing in the ROC curve analysis (area under the curve: 0.69 vs 0.60, Delong test P = .029). Time to VF was shorter for subjects with 454-GSS < 3 vs 454-GSS ≥ 3 (Log-rank P = .003) but not significantly different between Sanger-GSS < 3 and ≥3. Factors independently associated with increased risk of VF in multivariate Cox regression were a 454-GSS < 3 (HR = 4.6, 95 CI, [1.5, 14.0], P = .007), and the number of previous antiretrovirals received (HR = 1.2 per additional drug, 95 CI, [1.1, 1.3], P = .001). Equivalent findings were obtained with the ANRS and REGA algorithms. CONCLUSIONS: Ultrasensitive HIV-1 genotyping improves GSS-based predictions of virological outcomes of salvage ART relative to Sanger sequencing. This may improve the clinical management of ART-experienced subjects living with HIV-1. CLINICAL TRIALS REGISTRATION: NCT01346878.

Pneumocystis jirovecii pneumonia in HIV-1-infected patients in the late-HAART era in developed countries.

BACKGROUND: In developed countries with free access to health care, primary chemoprophylaxis with co-trimoxazole, and antiretroviral treatment, Pneumocystis pneumonia (PCP) in HIV-infected subjects should be restricted to undiagnosed late presenters. METHODS: We retrospectively identified confirmed PCP hospital admissions in HIV-1 patients (period 1986-2010) and examined their characteristics and factors associated with mortality. RESULTS: Three hundred and twelve episodes (median CD4 27 cells/µl) were identified during 3 periods: pre-HAART (1986-1995), 49%; early-HAART (1996-1999), 17.3%; and late-HAART (2000-2010), 33.7%. PCP was the initial AIDS-defining diagnosis in only 86 (27.6%). Thirty-four (10.9%) patients died during their hospital stay, without a significant reduction in mortality in recent periods (p = 0.311). However, the 12-month mortality decreased through the periods (33.3% to 16.2%; p = 0.003). Drug users (p = 0.001) and those naïve to HAART (p < 0.001) decreased in the late-HAART era, while heterosexuals (p = 0.001), immigrants (p < 0.001), and HAART initiation before hospital discharge (p < 0.001) increased. A partial pressure of oxygen (PaO2) ≤ 55 (p = 0.04), intensive care admission (p < 0.001), and the absence of HAART initiation before discharge (p = 0.02) were correlated with mortality. CONCLUSIONS: The epidemiology and 12-month mortality of HIV-1-infected subjects with PCP have changed significantly in the late-HAART era, while mortality during hospital stay has remained unchanged. HIV diagnosed individuals lost to follow-up in care have emerged as the main driver of PCP in developed countries. Like HIV late presenters, they are more likely to have AIDS-defining illnesses, to be hospitalized, and to die. This finding has important implications for the design of better strategies to retain HIV-1-infected individuals in care.

A Randomized Trial of Dolutegravir Plus Darunavir/Cobicistat as a Switch Strategy in HIV-1-Infected Patients With Resistance to at Least 2 Antiretroviral Classes.

Background: Suppressed patients with drug-resistant HIV-1 require effective and simple antiretroviral therapy to maintain treatment adherence and viral suppression. Methods: This randomized, open-label, noninferiority, multicenter pilot study involved HIV-infected adults who met the following criteria: confirmed HIV-1 RNA <50 copies/mL for ≥6 months preceding the study randomization, treatment with at least 3 antiretroviral drugs, and a history of drug resistance mutations against at least 2 antiretroviral classes but remaining fully susceptible to darunavir (DRV) and integrase inhibitors. Participants were randomized 1:1 to switch to dolutegravir (DTG; 50 mg once per day) plus DRV boosted with cobicistat (DRV/c; 800/150 mg once per day; 2D group) or continue with their baseline regimen (standard-of-care [SOC] group). The primary endpoint was the proportion of patients with HIV-1 RNA <50 copies/mL at week 48 relative to time to loss of virologic response, with a noninferiority margin set at -12.5%. Virologic failure was defined as confirmed HIV-1 RNA ≥50 copies/mL or a single determination of HIV-1 RNA >50 copies/mL followed by antiretroviral therapy discontinuation. Results: Forty-five participants were assigned to the 2D group and 44 to the SOC group. Time to loss of virologic response showed no difference in the proportion maintaining HIV-1 RNA <50 copies/mL at week 48: 39 of 45 (86.7%; 95% CI, 73.21%-94.95%) in the 2D group vs 42 of 44 (95.4%; 95% CI, 84.53%-99.44%) in the SOC group (log-rank P = .159) with an estimated difference of -8.7 (95% CI, -22.72 to 5.14). Only 2 (4.5%) in the SOC group experienced virologic failure, and 3 participants from the 2D group experienced adverse events leading to treatment discontinuation. Conclusions: In suppressed patients with at least 2 resistant antiretroviral classes, noninferiority could not be demonstrated by fully active DRV/c plus DTG. Nevertheless, there were no unexpected adverse events or virologic failure. DRV/c plus DTG may be considered a once-daily therapy option only for well-selected patients. Clinical Trials Registration. ClinicalTrials.gov (NCT03683524).

Outbreaks of dermatopathy caused by Tephrosia noctiflora intoxication in Brazilian cattle.

This study aims to update the knowledge concerning the intoxication by Tephrosia noctiflora in Brazilian cattle herds by reporting new cases of intoxication in lactating cows, their calves and bulls and highlight the epidemiology, clinical signs, pathogenesis, gross, and microscopic lesions. The morbidity and mortality of this intoxication in the farms studied was low. Gross lesions in all affected cattle consisted of dermatitis with hyperpigmentation, crusts, ulceration, erythema, and lichenification in the skin of limbs, ventral abdomen, perianal and perineal areas of lactating calves and adult cattle. Microscopically, the main lesion observed consisted of severe dermatitis with parakeratotic hyperkeratosis, papillated proliferation, and diffuse, accentuated lymphoplasmacytic inflammatory infiltrate in the epidermis and dermis. The presence of skin lesions mainly in the limbs and ventral abdomen of cattle implies the pathogenesis of intoxication is related to a primary contact dermatitis, and the occurrence of similar lesions on the skin of nursing calves reinforces this hypothesis. The putative toxins of T. noctiflora have been thought to be rotenoids. Additional work is needed to define better if these compounds are the main toxin responsible for the dermatopathy observed in these herds.

Mutations in the protease gene associated with virological failure to lopinavir/ritonavir-containing regimens.

OBJECTIVES: To assess the most frequent resistance-associated mutations (RAMs) to lopinavir/ritonavir in a cohort of patients attended in daily practice. METHODS: We retrospectively identified 195 multitreated subjects with virological failure. Patients were classified as follows: (i) 71 (36.4%) never received lopinavir/ritonavir (lopinavir/ritonavir naive); (ii) 75 (38.5%) had previously failed on lopinavir/ritonavir; and (iii) 49 (25.1%) were on lopinavir/ritonavir at failure. RAM patterns were assessed. Medians, IQRs, percentages, Kruskal-Wallis, χ(2) or Fisher's exact test, and multinomial logistic regression were used whenever appropriate. RESULTS: L10I/F, K20R, L24I, L33F, M36I, M46I/L, I47V, G48V, F53L, I54V, A71V, G73S, V82A, I84V and L90M (all with P ≤ 0.037) were protease RAMs overexpressed in patients with lopinavir/ritonavir failure. L10I, M36I, M46I, I54V, L63P, A71V, V82A, I84V and L90M were the most common in lopinavir/ritonavir-naive patients. Other IAS-USA RAMs for lopinavir/ritonavir (L10R/V, K20M, V32I, I47A, I50V, I54L/A/M/T/S, A71T, L76V and V82F/T/S) were not associated with previous or current failure to lopinavir/ritonavir. Lopinavir/ritonavir failure was associated with the number of protease RAMs (OR = 1.146, 95% CI = 1.287, 1.626), higher exposure to protease inhibitors, and the presence of E44D, L33F, I54V and I84V. CONCLUSIONS: In multitreated patients with previous or current lopinavir/ritonavir failure, some protease mutations are selected at significantly greater rates. L10I, M36I, I54V, L63P, A71V, V82A and L90M were found in >50% of cases. Thus, their presence should be expected when genotypic testing results are not available. The number of protease RAMs and higher prior exposures to protease inhibitors were significantly associated with lopinavir/ritonavir failure.

Dermatopathy caused by Tephrosia noctiflora intoxication in cattle.

An outbreak of a disease characterized by emaciation, dermatitis with erythema, alopecia, foul-smelling exudation, crusting, hyperpigmentation, lichenification, and edema of fore- and hindlimbs, chest and dewlap is described affecting cattle in the State of Alagoas, Northeastern Brazil. Microscopically, the main lesions were characterized by diffuse dermatitis with infiltration of lymphocytes, histiocytes, parakeratotic hyperkeratosis and acanthosis. The plant Tephrosia noctiflora, which exhibited signs of consumption, infested the grazing areas of cattle. To test its toxicity, T. noctiflora was harvested, dried in the shade, crushed and sourced at a concentration of 50% mixed with commercial food for three guinea pigs. The main clinical signs in guinea pigs included weight loss and multifocal, moderate to severe areas of alopecia, diffuse erythema of the skin, vaginal edema and hematuria. Microscopically, lymphocytic and histiocytic dermatitis, parakeratotic hyperkeratosis and acanthosis were noted in guinea pigs. This experiment confirms that T. noctiflora is the cause of outbreaks of dermatitis observed in cattle grazing in areas infested by this plant.

Neuroinflammation in early, late and recovery stages in a progressive parkinsonism model in rats.

Parkinson's disease (PD) is characterized by motor and non-motor signs, which are accompanied by progressive degeneration of dopaminergic neurons in the substantia nigra. Although the exact causes are unknown, evidence links this neuronal loss with neuroinflammation and oxidative stress. Repeated treatment with a low dose of reserpine-inhibitor of VMAT2-has been proposed as a progressive pharmacological model of PD. The aim of this study was to investigate whether this model replicates the neuroinflammation characteristic of this disease. Six-month-old Wistar rats received repeated subcutaneous injections of reserpine (0.1 mg/kg) or vehicle on alternate days. Animals were euthanized after 5, 10, or 15 injections, or 20 days after the 15th injection. Catalepsy tests (motor assessment) were conducted across treatment. Brains were collected at the end of each treatment period for immunohistochemical and RT-PCR analyzes. Reserpine induced a significant progressive increase in catalepsy duration. We also found decreased immunostaining for tyrosine hydroxylase (TH) in the substantia nigra pars compacta (SNpc) and increased GFAP + cells in the SNpc and dorsal striatum after 10 and 15 reserpine injections. Phenotyping microglial M1 and M2 markers showed increased number of CD11b + cells and percentage of CD11b + /iNOS + cells in reserpine-treated animals after 15 injections, which is compatible with tissue damage and production of cytotoxic factors. In addition, increased CD11b + /ArgI + cells were found 20 days after the last reserpine injection, together with an increment in IL-10 gene expression in the dorsal striatum, which is indicative of tissue repair or regeneration. Reserpine also induced increases in striatal interleukin TNF-alpha mRNA levels in early stages. In view of these results, we conclude that reserpine-induced progressive parkinsonism model leads to neuroinflammation in regions involved in the pathophysiology of PD, which is reversed 20 days after the last injection. These findings reveal that withdrawal period, together with the shift of microglial phenotypes from the pro-inflammatory to the anti-inflammatory stage, may be important for the study of the mechanisms involved in reversing this condition, with potential clinical applicability.

Testosterone propionate improves motor alterations and dopaminergic damage in the reserpine-induced progressive model of Parkinson's disease.

Parkinson's disease (PD) is a chronic and progressive neurodegenerative disorder with a higher susceptibility to occur in men. Studies suggest that this susceptibility is related to the hormonal differences observed between men and women, being a risk factor for PD. In addition, testosterone supplementation has shown controversial results in animal models of PD and parkinsonian patients. This study evaluated the effect of chronic administration of testosterone propionate (TP) on motor behavior and neurochemical parameters in the reserpine-induced rat model of parkinsonism. Male Wistar rats received 15 injections of reserpine (RES - 0.1 mg/kg) every other day and were concomitantly treated with different doses (0.1, 1.0, or 5.0 mg/kg) of daily TP for 30 days. The rats were euthanized 48 h after the 15th injection of RES or vehicle. Brains were removed and subjected to Tyrosine hydroxylase (TH) immunohistochemistry. TP at 1.0 mg/kg reduced the damages caused by reserpine in the vacuous chewing and tong protrusion behaviors and prevented dopaminergic damage in the SNpc, VTA, and Striatum. TP at 5.0 mg/kg reduced the damages caused by reserpine in the catalepsy and tong protrusion behaviors, prevented the weight loss, and prevented dopaminergic damage in the VTA. Our results suggest that chronic administration of TP has a protective effect in a rat model of parkinsonism, improving motor alterations and dopamine depletion induced by RES.

Aging accentuates decrease in tyrosine hydroxylase immunoreactivity associated with the increase in the motor impairment in a model of reserpine-induced parkinsonism.

Parkinson's disease (PD) is an age-related neurodegenerative disorder characterized by progressive dopaminergic neuron loss. Animal models have been used to develop a better understanding of the pathophysiologic mechanisms of PD. However, these models are usually conducted with young animals diverging of the age of PD patients, suggesting a bias in translational science. Thus, the aim of the study was to evaluate the effect of the age on rats in a progressive parkinsonism model induced by reserpine (RES). Adult (6 - 8 month-old) or elderly (18 - 24 month-old) male rats were assigned to six groups: control-elderly (CTL-ELDERLY), reserpine-elderly (RES-ELDERLY), reserpine-elderly withdrawal (RES-ELDERLY WITHDRAWAL), control-adult (CTL-ADULT), reserpine-adult (RES-ADULT), and reserpine-adult withdrawal (RES-ADULT WITHDRAWAL). Animals received 15 injections every other day of RES (0.1 mg / kg) or vehicle during 30 days. Throughout treatment, animals were evaluated in the catalepsy test (every 48 h) and open field test (24 h after the second injection), and weight assessment (every 4 days) was also made. Upon completion of behavioral tests, rat brains were collected for tyrosine hydroxylase (TH) immunohistochemical analysis. Main results demonstrated that RES-treated animals spent more time in the catalepsy bar compared with control groups, moreover the RES-elderly group showed a longer catalepsy time compared with the RES-ADULT group. A shorter time from RES treatment to the development of symptoms was observed in the RES-ADULT group, compared with the RES-ELDERLY group. In addition, RES-induced weight loss in both RES-ELDERLY and RES-ADULT when compared with their corresponding controls. Cessation of RES treatment was followed by weight gain only in the RES-ADULT group. A significant decrease in TH-immunoreactive cells was observed in the substantia nigra pars compacta (SNpc) and dorsal striatum (STR) in the rats in both the RES-ADULT and RES-ELDERLY groups and in the ventral tegmental area in rats in the RES-ADULT group. Furthermore, TH immunoreactivity decrease was not reversible in SNpc and STR in the RES-ELDERLY. These results show that RES has an age-dependent effect in rats, suggesting a greater sensitivity of the dopaminergic pathway to RES with advancing age. These suggest that the RES rat model of parkinsonism can be useful in improving our knowledge on the effect of aging on neurodegeneration.

Motor, memory, and anxiety-like behavioral impairments associated with brain-derived neurotrophic factor and dopaminergic imbalance after inhalational exposure to deltamethrin.

Believed to cause damage to the nervous system and possibly being associated with neurodegenerative diseases, deltamethrin (DM) is a type II pyrethroid used in pest control, public health, home environment, and vector control. The objective of this study was to evaluate the motor, cognitive and emotional changes associated with dopaminergic and BDNF imbalance after DM exposure in rats. Sixty Wistar rats (9-10 months-old) were used, under Ethics Committee on Animal Research license (ID 19/2017). The animals were randomly divided into four groups: control (CTL, 0.9% saline), DM2 (2 mg DM in 1.6 mL 0.9% saline), DM4 (4 mg of DM in 1.6 mL of 0.9% saline), and DM8 (8 mg of DM in 1.6 mL of 0.9% saline). DM groups were submitted to 9 or 15 inhalations, one every 48 h. Half of the animals from each group were randomly selected and perfused 24 h after the 9th or 15th inhalation. Throughout the experiment, the animal's behavior were evaluated using catalepsy test, open field, hole-board test, Modified Elevated Plus Maze, and social interaction. At the end of the experiments, the rats were perfused transcardially and their brains were processed for Tyrosine Hydroxylase (TH) and Brain derived neurotrophic factor (BDNF) immunohistochemistries. The animals submitted to 9 inhalations of DM showed a reduction in immunoreactivity for TH in the Substantia nigra pars compacta (SNpc), ventral tegmental area (VTA), and dorsal striatum (DS) areas, and an increase in BDNF in the DS and CA1, CA3 and dentate gyrus (DG) hippocampal areas. Conversely, the animals submitted to 15 inhalations of DM showed immunoreactivity reduced for TH in the SNpc and VTA, and an increase in BDNF in the hippocampal areas (CA3 and DG). Our results indicate that the DM inhalation at different periods induce motor and cognitive impairments in rats. Such alterations were accompanied by dopaminergic system damage and a possible dysfunction on synaptic plasticity.

Efficacy and safety of nucleoside reverse transcriptase inhibitor-sparing salvage therapy for multidrug-resistant HIV-1 infection based on new-class and new-generation antiretrovirals.

BACKGROUND: The advent of new antiretrovirals has expanded the therapeutic options for multiple drug-resistant HIV-1 infection. The role of recycled nucleoside reverse transcriptase inhibitors (NRTIs) in this scenario remains uncertain. METHODS: Observational study of 122 consecutive patients with prior triple-class failure and multidrug-resistant HIV infection who started a salvage regimen with at least three of the new antiretrovirals darunavir, etravirine, raltegravir and maraviroc. Virological, immunological and clinical outcomes were compared according to the inclusion or not of NRTIs in the regimen, after 48 weeks of follow-up. RESULTS: All patients received at least two and 65% received three fully active drugs in the salvage regimen. In 63 patients recycled NRTIs were added to new drugs (NRTI-containing group) and 59 patients did not receive NRTIs (NRTI-sparing group). Both groups were comparable at baseline regarding the number of prior failures, resistance profile, CD4 cell count and HIV plasma viral load. The rates of HIV-1 RNA suppression below 50 copies/mL at week 48 (intent-to-treat analysis) were similar in the two groups: 46/59 [78%, 95% confidence interval (CI) 67%-88%] in the NRTI-sparing group and 49/63 (78%, 95% CI 67%-88%) in the NRTI-containing group. No significant differences were found in CD4 cell count increases. Drug-related adverse events leading to drug discontinuations only occurred in the NRTI-containing group (5 of 63, NRTI-related in 3 cases). CONCLUSIONS: The addition of NRTIs with reduced activity, according to genotypic resistance tests, does not seem to improve the efficacy of salvage regimens containing three of the new antiretrovirals in patients with multidrug-resistant HIV-1 infection.