Depression, an unmet health need in Africa: Understanding the promise of ketamine.

In Africa, there is currently a paucity of data on the epidemiology of depression, its treatment and management. The prevalence of depression is severely underestimated, with unique circumstances and societal risk factors associated with depression and its public awareness. Treating and managing depression is confounded by an inaccessibility to efficient and low-cost treatments for patients with depression. The aetiology of depression is multifactorial, with various theories implicating multiple neuronal networks. Despite this, the treatment of depression is one-dimensional focussing on outdated theories of depression and mainly targeting dysfunctional neurotransmitter pathways. Hence, it is not surprising that there is a significant increase in the prevalence of patients suffering from treatment resistant depression (TRD), with a large portion of patients deriving little clinical benefit from these traditional anti-depressant therapies. This highlights the need for more effective treatment strategies for depression, especially applicable to resource limited environments such as Africa, where there is little investment in public healthcare resources towards managing mental health disorders. The clinical potential of using ketamine in managing depression has received considerable attention in the past two decades, with the FDA approving esketamine for the management of TRD in 2019. This widespread attention has significantly increased ketamine's appeal as a novel antidepressant. Consequently, many ketamine infusion clinics have been established in Africa. However, there is little regulation or guidance for ketamine infusions. Furthermore, while esketamine is expensive and hence inaccessible to a large portion of the African population, racemic ketamine is significantly cheaper and has demonstrated clinical potential. However, there is currently a limited understanding of the neurological mechanisms of action of racemic ketamine in treating and managing depression, especially in a diverse African population. Therefore, this review aims to provide an African context of depression and the therapeutic potential of ketamine by highlighting aspects of its molecular mechanism of action.

Neurobehavioral and molecular changes in a rodent model of ACTH-induced HPA axis dysfunction.

Hypothalamic-pituitary-adrenal (HPA) axis dysregulation is linked to the pathophysiology of depression. Although exogenous adrenocorticotropic hormone (ACTH) is associated with a depressive-like phenotype in rodents, comprehensive neurobehavioral and mechanistic evidence to support these findings are limited. Sprague-Dawley rats (male, n = 30; female, n = 10) were randomly assigned to the control (male, n = 10) or ACTH (male, n = 20; female n = 10) groups that received saline (0.1 ml, sc.) or ACTH (100 µg/day, sc.), respectively, for two weeks. Thereafter, rats in the ACTH group were subdivided to receive ACTH plus saline (ACTH_S; male, n = 10; female, n = 5; 0.2 ml, ip.) or ACTH plus imipramine (ACTH_I; male, n = 10; female, n = 5;10 mg/kg, ip.) for a further four weeks. Neurobehavioral changes were assessed using the forced swim test (FST), the sucrose preference test (SPT), and the open field test (OFT). Following termination, the brain regional mRNA expression of BDNF and CREB was determined using RT-PCR. After two-weeks, ACTH administration significantly increased immobility in the FST (p = 0.03), decreased interaction with the center of the OFT (p < 0.01), and increased sucrose consumption (p = 0.03) in male, but not female rats. ACTH administration significantly increased the expression of BDNF in the hippocampus and CREB in all brain regions in males (p < 0.05), but not in female rats. Imipramine treatment did not ameliorate these ACTH-induced neurobehavioral or molecular changes. In conclusion, ACTH administration resulted in a sex-specific onset of depressive-like symptoms and changes in brain regional expression of neurotrophic factors. These results suggest sex-specific mechanisms underlying the development of depressive-like behavior in a model of ACTH-induced HPA axis dysregulation.

CB2 agonist mitigates cocaine-induced reinstatement of place preference and modulates the inflammatory response in mice.

Chronic exposure to cocaine is known to have profound effects on the brain, leading to the dysregulation of inflammatory signalling pathways, the activation of microglia, and the manifestation of cognitive and motivational behavioural impairments. The endocannabinoid system has emerged as a potential mediator of cocaine's deleterious effects. In this study, we sought to investigate the therapeutic potential of the cannabinoid CB2 receptor agonist, JWH-133, in mitigating cocaine-induced inflammation and associated motivational behavioural alterations in an in vivo model. Our research uncovered compelling evidence that JWH-133, a selective CB2 receptor agonist, exerts a significant dampening effect on the reinstatement of cocaine-induced conditioned place preference. This effect was accompanied by notable changes in the neurobiological landscape. Specifically, JWH-133 administration was found to upregulate Δ-FOSB expression in the nucleus accumbens (Nac), elevate CX3CL1 levels in both the ventral tegmental area and prefrontal cortex (PFC), and concurrently reduce IL-1ß expression in the PFC and NAc among cocaine-treated animals. These findings highlight the modulatory role of CB2 cannabinoid receptor activation in altering the reward-seeking behaviour induced by cocaine. Moreover, they shed light on the intricate interplay between the endocannabinoid system and cocaine-induced neurobiological changes, paving the way for potential therapeutic interventions targeting CB2 receptors in the context of cocaine addiction and associated behavioural deficits.

Toward Multiscale Measurement-Informed Methane Inventories: Reconciling Bottom-Up Site-Level Inventories with Top-Down Measurements Using Continuous Monitoring Systems.

Government policies and corporate strategies aimed at reducing methane emissions from the oil and gas sector increasingly rely on measurement-informed, site-level emission inventories, as conventional bottom-up inventories poorly capture temporal variability and the heavy-tailed nature of methane emissions. This work is based on an 11-month methane measurement campaign at oil and gas production sites. We find that operator-level top-down methane measurements are lower during the end-of-project phase than during the baseline phase. However, gaps persist between end-of-project top-down measurements and bottom-up site-level inventories, which we reconcile with high-frequency data from continuous monitoring systems (CMS). Specifically, we use CMS to (i) validate specific snapshot measurements and determine how they relate to the temporal emission profile of a given site and (ii) create a measurement-informed, site-level inventory that can be validated with top-down measurements to update conventional bottom-up inventories. This work presents a real-world demonstration of how to reconcile CMS rate estimates and top-down snapshot measurements jointly with bottom-up inventories at the site level. More broadly, it demonstrates the importance of multiscale measurements when creating measurement-informed, site-level emission inventories, which is a critical aspect of recent regulatory requirements in the Inflation Reduction Act, voluntary methane initiatives such as the Oil and Gas Methane Partnership 2.0, and corporate strategies.

Multiscale Methane Measurements at Oil and Gas Facilities Reveal Necessary Frameworks for Improved Emissions Accounting.

Methane mitigation from the oil and gas (O&G) sector represents a key near-term global climate action opportunity. Recent legislation in the United States requires updating current methane reporting programs for oil and gas facilities with empirical data. While technological advances have led to improvements in methane emissions measurements and monitoring, the overall effectiveness of mitigation strategies rests on quantifying spatially and temporally varying methane emissions more accurately than the current approaches. In this work, we demonstrate a quantification, monitoring, reporting, and verification framework that pairs snapshot measurements with continuous emissions monitoring systems (CEMS) to reconcile measurements with inventory estimates and account for intermittent emission events. We find that site-level emissions exhibit significant intraday and daily emission variations. Snapshot measurements of methane can span over 3 orders of magnitude and may have limited application in developing annualized inventory estimates at the site level. Consequently, while official inventories underestimate methane emissions on average, emissions at individual facilities can be higher or lower than inventory estimates. Using CEMS, we characterize distributions of frequency and duration of intermittent emission events. Technologies that allow high sampling frequency such as CEMS, paired with a mechanistic understanding of facility-level events, are key to an accurate accounting of short-duration, episodic, and high-volume events that are often missed in snapshot surveys and to scale snapshot measurements to annualized emissions estimates.

Longitudinal Patterns of Suicidality Among Heroin Users in Johannesburg, South Africa: A Need for Suicide Screening and Intervention.

Objectives: The objective of the study was to longitudinally assess the outcomes and correlates of suicidal ideation and behavior (SIB) among heroin users who attended inpatient detoxification and psychosocial rehabilitation. SIB was assessed in 300 heroin users upon entry into inpatient detoxification (baseline) as well as 3-months (t1) (n = 252; 84%) and 9-months (t2) (n = 225; 75%) post treatment. Multivariable logistic regression was used to determine the demographic, clinical and treatment related factors that increased the risk for a high SIB score. Results: From baseline to t1 there was a significant decrease in the proportion of those who endorsed SIB (68.7 vs. 38.9%, p < 0.0001). There was an increase in the proportion of those who endorsed SIB from t1 to t2 (38,9 vs. 47.1%, p = 0.047). There was a significant increase in the proportion of those reporting suicide likely in the near future from baseline to t1 (8.7 vs. 16.3%: p < 0.0049) and this was repeated from t1 to t2 (22.7%) (t1 vs. t2: p = 0.031). After controlling for all other variables, a comorbid mental illness (MI) at baseline was a significant independent risk factor for a high SIB score at t1(RR 1.63; 95% CL 1.30-2.03) (p < 0.0001) and a comorbid MI at t1 increased the risk for a high SIB score at t2 (RR 2.73; 95% CL 1.78-4.19) (p < 0.0001). A poorer general health score and poorer social functioning score at baseline were associated with a high SIB score at baseline (RR 1.02; 95% CL 1.01-1.04) (p = 0.001) and t2, respectively (RR 1.07; 95% CL 1.04-1.11) (p < 0.0001). Conclusions: Among heroin users, a comorbid mental illness, poorer physical health and poorer social functioning are important factors to consider in suicide risk assessment. Although there were decreases in overall SIB 3 months after detoxification, this trend was not sustained at 9-month follow-up. After detoxification there were significant increases in the proportion of those reporting a likelihood of suicide in the following 3 months. The results suggests that the treatment exposure did not adequately mitigate suicide risk. There is a need for review of the treatment as well as targeted screening and management of SIB in heroin users attending treatment services.

What is next in African neuroscience?

Working in Africa provides neuroscientists with opportunities that are not available in other continents. Populations in this region exhibit the greatest genetic diversity; they live in ecosystems with diverse flora and fauna; and they face unique stresses to brain health, including child brain health and development, due to high levels of traumatic brain injury and diseases endemic to the region. However, the neuroscience community in Africa has yet to reach its full potential. In this article we report the outcomes from a series of meetings at which the African neuroscience community came together to identify barriers and opportunities, and to discuss ways forward. This exercise resulted in the identification of six domains of distinction in African neuroscience: the diverse DNA of African populations; diverse flora, fauna and ecosystems for comparative research; child brain health and development; the impact of climate change on mental and neurological health; access to clinical populations with important conditions less prevalent in the global North; and resourcefulness in the reuse and adaption of existing technologies and resources to answer new questions. The article also outlines plans to advance the field of neuroscience in Africa in order to unlock the potential of African neuroscientists to address regional and global mental health and neurological problems.

Prolonged drying trend coincident with the demise of Norse settlement in southern Greenland.

Declining temperature has been thought to explain the abandonment of Norse settlements, southern Greenland, in the early 15th century, although limited paleoclimate evidence is available from the inner settlement region itself. Here, we reconstruct the temperature and hydroclimate history from lake sediments at a site adjacent to a former Norse farm. We find no substantial temperature changes during the settlement period but rather that the region experienced a persistent drying trend, which peaked in the 16th century. Drier climate would have notably reduced grass production, which was essential for livestock overwintering, and this drying trend is concurrent with a Norse diet shift. We conclude that increasingly dry conditions played a more important role in undermining the viability of the Eastern Settlement than minor temperature changes.

Differential Expression of Platelet Activation Markers, CD62P and CD63, after Exposure to Breast Cancer Cells Treated with Kigelia Africana, Ximenia Caffra and Mimusops Zeyheri Seed Oils In Vitro.

Cancer patients, including breast cancer patients, live in a hypercoagulable state. Chemo- and hormone- therapy used in the treatment of breast cancer increases the risk of thrombosis. Due to differences in health care services between developed and developing countries, the survival rate of women with breast cancer in developing countries is low. Consequently, ethnomedicines are used and their efficacy as potential alternatives are being scientifically explored. The seed oils of Kigelia africana, Ximenia caffra and Mimusops zeyheri have anti-proliferative effects on hormone-dependent (MCF-7) and cytotoxic effects on hormone-independent (MDA-MB-231) breast cancer cells. In this study, we determined if these seed oils reduce the thrombogenic ability of breast cancer cells by measuring the platelet surface expression of the activation-specific antigens CD62P and CD63. MDA-MB-231 and MCF-7 cells were pretreated with the seed oils before being exposed to whole blood of human female volunteers. An increase in CD62P and CD63 expression following whole blood exposure to untreated breast cancer cells was observed. Treated MDA-MB-231 cells reduced CD62P and CD63 expression while treated MCF-7 cells increased CD62P and decreased CD63 expression. Kigelia africana, Ximenia caffra and Mimusops zeyheri seed oils are able to reduce the thrombogenic ability of MDA-MB-231 breast cancer cells.

Effects of combination antiretroviral drugs (cART) on hippocampal neuroplasticity in female mice.

The incidence of HIV-associated neurocognitive disorder (HAND) continues despite the introduction of combination antiretroviral drugs (cART). Several studies have reported the neurotoxicity of individual antiretroviral drugs (monotherapy), while the common approach for HIV treatment is through cART. Hence, the current study investigated the effects of long-term exposure to cART on cognitive function, oxidative damage, autophagy, and neuroplasticity in the hippocampus of mice. Female Balb/c mice received a once-a-day oral dose of cART composed of emtricitabine + tenofovir disoproxil fumarate or vehicle for 8 weeks. On week 7 of drug administration, all mice were assessed for spatial learning in the Morris water maze (MWM), and then on week 8, mice were sacrificed, and hippocampal tissue dissected from the brain. For biochemical analyses, we measured the concentration of 4-hydroxynonenal, and the expression of autophagic marker LC3B, synaptophysin, and brain-derived neurotrophic factor (BDNF) in the hippocampus. Our results showed that cART exposure increased escape latency in the MWM test. The cART-treated mice also showed increased 4-hydroxynonenal concentration and expression of LC3B. Furthermore, cART treatment decreased the expression of synaptophysin and BDNF. These findings further support the evidence that cART may be neurotoxic and therefore may play a role in the neuropathogenesis of HAND.

Fronto-temporal cortical atrophy in 'nyaope' combination heroin and cannabis use disorder.

Sub-Saharan Africa is one of the top three regions with the highest rates of opioid-related premature mortality. Nyaope is the street name for what is believed to be a drug cocktail in South Africa although recent research suggests that it is predominantly heroin. Nyaope powder is most commonly smoked together with cannabis, a drug-use pattern unique to the region. Due to the increasing burden of this drug in low-income communities and the absence of human structural neuroimaging data of combination heroin and cannabis use disorder, we initiated an important cohort study in order to identify neuroanatomical sequelae. Twenty-eight male nyaope users and thirty healthy, matched controls were recruited from drug rehabilitation centers and the community, respectively. T1-weighted MRI images were obtained using a 3 T General Electric Discovery and cortical thickness was examined and compared. Nyaope users displayed extensive grey matter atrophy in the right hemispheric medial orbitofrontal, rostral middle frontal, superior temporal, superior frontal, and supramarginal gyri (two-sided t-test, p < 0.05, corrected for multiple comparisons). Our findings indicate cortical abnormality in nyaope users in regions involved in impulse control, decision making, social- and self-perception, and working memory. Importantly, affected brain regions show large overlap with the pattern of cortical abnormalities shown in heroin use disorder.

Long-Term Treatment with Fluvoxamine Decreases Nonmotor Symptoms and Dopamine Depletion in a Postnatal Stress Rat Model of Parkinson's Disease.

Nonmotor symptoms (NMS) such as anxiety, depression, and cognitive deficits are frequently observed in Parkinson's disease (PD) and precede the onset of motor symptoms by years. We have recently explored the short-term effects of Fluvoxamine, a selective serotonin reuptake inhibitor (SSRI) on dopaminergic neurons in a parkinsonian rat model. Here, we report the long-term effects of Fluvoxamine, on early-life stress-induced changes in the brain and behavior. We specifically evaluated the effects of Fluvoxamine on brain mechanisms that contribute to NMS associated with PD in a unilateral 6-hydroxydopamine-lesioned rat model. A 14-day early postnatal maternal separation protocol was applied to model early-life stress followed by unilateral intracerebral infusion of 6-hydroxydopamine (6-OHDA) to model aspects of parkinsonism in rats. The anxiolytic, antidepressant, and cognitive effects of Fluvoxamine were confirmed using the elevated plus-maze (EPM) test, sucrose preference test (SPT), and Morris water maze (MWM) test. Further to that, our results showed that animals exposed to early-life stress displayed increased plasma corticosterone and malondialdehyde (MDA) levels which were attenuated by Fluvoxamine treatment. A 6-OHDA lesion effect was evidenced by impairment in the limb-use asymmetry test as well as decreased dopamine (DA) and serotonin levels in the striatum, prefrontal cortex, and hippocampus. These effects were surprisingly attenuated by Fluvoxamine treatment in all treated rats. This study is the first to suggest that early and long-term treatment of neuropsychological diseases with Fluvoxamine may decrease the vulnerability of dopaminergic neurons that degenerate in the course of PD.

Dielectric Constant and Conductivity of Blood Plasma: Possible Novel Biomarkers for Alzheimer's Disease.

Alzheimer's disease is a complex debilitating neurodegenerative disease for which there is no cure. The lack of reliable biomarkers for Alzheimer's disease has made the evaluation of the efficacy of new treatments difficult and reliant on only clinical symptoms. In an aged population where cognitive function may be deteriorating for other reasons, the dependence on clinical symptoms is also unreliable. However, it is well established that infusion of ß-amyloid into the dorsal hippocampus of rats leads to cognitive impairment in a rat model of Alzheimer's disease. Moreover, the blood plasma of ß-amyloid-lesioned rats exhibits a distinct variation of the dielectric constant and conductivity when compared to that of normal rats in a time-dependent manner. These two electric parameters of blood plasma may therefore act as potential biomarkers for dementia due to Alzheimer's disease. This review is aimed at highlighting evidences that support blood plasma electrical properties, e.g., dielectric constant and conductivity as possible novel biomarkers for the early development and progression of dementia due to Alzheimer's disease.

An Inverse Relationship Between Alcohol and Heroin Use in Heroin Users Post Detoxification.

BACKGROUND: Given that fewer than 50% of countries provide Opioid Agonist Maintenance Therapies (OAMT), it is important to assess whether other substances act as a substitute for heroin in recovering heroin users who receive detoxification models of treatment. There is a dearth of prospective studies from low-and-middle-income countries evaluating these patterns of substance use. METHODS: 300 heroin users from the Gauteng province of South Africa were assessed on entry into inpatient detoxification and then followed-up 3 and 9 months after leaving treatment. Treatment consisted of 1 week of detoxification followed by 6-8 weeks of psychosocial therapy. We measured the overall changes in the prevalence of heroin, alcohol and other drug use at baseline and postrehabilitation. Comparison of these outcomes at enrolment, 3 months and 9 months was performed by a Generalised Estimating Equation (GEE) with the outcome as the dependent variable, observation point as the independent variable, and participant as the repeated measure. Injecting status and treatment completion were included as covariates. We also measured the individual pathways between heroin and alcohol use in the 210 participants that were seen at all three timepoints. RESULTS: Of the original cohort, 252 (84.0%) were re-interviewed at 3 months and 225 (75.0%) at 9 months. From baseline to 3 months, the proportion of past month heroin users decreased significantly to 65.5%; however, during this time, the proportion of past month alcohol users increased from 16.3% to 55.2% (p<0.0001). When assessing the pathways between heroin and alcohol use at an individual level, 55.4% (n-97) of those who were past month alcohol abstinent prior to rehabilitation were using alcohol at 3 months. From 3 to 9 months the proportion of heroin users increased to 72.4% (p<0.0001), and during this time, the proportion of alcohol users decreased. CONCLUSION: After detoxification, a significant reduction in heroin use was observed with a concomitant increase in alcohol consumption. Under these circumstances, alcohol may have acted as a substitute for heroin in the short term. The initial reduction in heroin use 3 months postrehabilitation was followed by increased consumption 6 months later. This observation supports the need for interventions to prevent, monitor and treat high levels of alcohol use in heroin users post detoxification. The provision of OAMT is a necessary consideration to address both the risk of increased alcohol intake as well as the decline in heroin abstinence rates.

Smoking heroin with cannabis versus injecting heroin: unexpected impact on treatment outcomes.

BACKGROUND: In several countries, especially in Africa, the dominant method of heroin intake is smoking a joint of cannabis laced with heroin. There is no data exploring the impact of smoking heroin with cannabis on treatment outcomes. AIM: To compare treatment outcomes between people who inject heroin and people who smoke heroin with cannabis. METHODOLOGY: Three hundred heroin users were assessed on admission to inpatient rehabilitation and after treatment. We compared drug use, psychopathology, criminality, social functioning and general health between heroin injectors and heroin-cannabis smokers at treatment entry, and at 3 and 9 months after rehabilitation. RESULTS: The sample comprised 211 (70.3%) heroin-cannabis smokers and 89 (29.7%) heroin injectors. Eighty-four percent were followed up at 3 months and 75% at 9 months. At 9 months, heroin-cannabis smokers had a higher proportion of those who relapsed to heroin use compared with intravenous (IV) users (p = 0.036). The median number of heroin use episodes per day was lower for IV users than heroin-cannabis smokers at both follow-up points (p = 0.013 and 0.0019). A higher proportion of IV users was HIV positive (p = 0.002). There were no significant differences in psychopathology, general health, criminality and social functioning between IV users and heroin-cannabis smokers at all three time points. CONCLUSIONS: Heroin users who do not inject drugs but use other routes of administration may have increased risk for relapse to heroin use after inpatient rehabilitation and should therefore have equal access to harm reduction treatment services. Advocating a transition from injecting to smoking heroin in an African context may pose unique challenges.

A prospective observational study of heroin users in Johannesburg, South Africa: Assessing psychiatric comorbidities and treatment outcomes.

BACKGROUND: Despite the rise in heroin use in sub Saharan-Africa opioid agonist maintenance treatment (OAMT) is still not state-funded in South Africa and many other African countries. In South Africa there has been little data published on the profile of heroin users and the outcomes of treatment for those who attend public treatment services. METHODS: 300 heroin users from two state-funded rehabilitation centres in Johannesburg were studied at entry into rehabilitation and 3-months after treatment. Treatment consisted of inpatient detoxification and inpatient psychosocial rehabilitation. Structured interviews measured changes in drug use, psychopathology and criminality post rehabilitation. RESULTS: Most (65.7%) smoked heroin in combination with cannabis while 29.7% were injecting users. Almost half the sample (49.3%) had at least one mental illness. Of the 252 (84%) participants seen at 3-month follow-up, 6.3% were abstinent of all substances (excluding tobacco), 65.5% had continued heroin use (CHU) and the balance used other substances. At follow-up there were significant decreases in heroin use (p<0.0001) and criminality (p<0.0001). There were however significant increases in alcohol use (p<0.0001), crystalmetamphetamine use (p=0.032) and the prevalence of current episode of major depression (p<0.0001). Just 11.9% received formal psychosocial treatment after leaving rehabilitation. None were on OAMT and only three participants were on psychotropic medication. None were tested for Hepatitis C during the study period and the majority (53%) did not know their HIV status. CONCLUSION: There are significant gaps in current treatment services for heroin users in South Africa. Retention in treatment and assessment and management of psychiatric and non-psychiatric comorbidities is low. Services need to be more integrated and should also include the provision of OAMT.

Cocaine-induced inheritable epigenetic marks may be altered by changing early postnatal fostering.

Here, we explored the hypothesis that parental cocaine exposure could alter epigenetic machinery in their drug-naive offspring while early postnatal fostering may further modify the accompanied neurochemical and functional components. Variant drug-naive pups were produced from cocaine-exposed or unexposed C57BL/6 female mice that were matched with their male counterparts for mating. Within 3 days of birth, half of the pups were cross-fostered and nurtured by non-biological lactating dams. The pups were initially examined for locomotor activity and memory performance and subsequently for changes in DNA methylation in promoter regions of cAMP response element modulator (Crem) and Fosb in the prefrontal cortex at 48 days postnatum. The impact of postnatal fostering on these parameters was also investigated. Our results showed that cocaine exposure significantly decreased both Crem and Fosb methylation in the prefrontal cortex of progenitor mice, while similar patterns of methylation were replicated in the brains of drug-naive non-fostered offspring mice but reversed by postnatal fostering. Furthermore, offspring raised by cocaine-exposed dams were impaired in discriminative learning and exhibited memory decline, whereas locomotor activity remains unaltered in all groups of mice. Our data provide some evidence that indirect exposure to cocaine may cause marked epigenetic changes within the cortical networks of drug-naive descendants and that mediation by Crem/Fosb signalling in this brain region may be beneficial, while early postnatal fostering may further engineer molecular switching that may predispose the individual to future risky behaviours as well as accumulative potential to developing cognitive impairment later in life.

Effect of long-term administration of antiretroviral drugs (Tenofovir and Nevirapine) on neuroinflammation and neuroplasticity in mouse hippocampi.

The use of combination antiretroviral therapy (cART) has been successful in suppressing HIV-1 replication and restoring peripheral immune functioning in HIV-infected individuals. Despite these advances in the management of HIV, neurocognitive impairments continue to be diagnosed in HIV-infected patients on treatment, even when the viral load is low. Of interest is the observation that deficiencies in brain function in these individuals are marked by a persistent presence of neuroinflammation. Therefore, in this study we investigated whether long-term exposure to ART could contribute to neuroinflammation. Mice were subsequently administered a daily single dose of either Tenofovir disoproxil fumarate or Nevirapine orally for 8 weeks. After treatment, hippocampal tissue was collected from the brains of drug-treated and control mice and the levels of interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α) and brain-derived neurotrophic factor (BDNF) determined. Our results showed that administration of Tenofovir disoproxil fumarate and Nevirapine induced astrogliosis and up-regulated IL-1ß and TNF-α. In addition, we found that Nevirapine reduced the expression of BDNF. Together these results suggest that Nevirapine promotes inflammatory and reduces neuroprotective processes in the hippocampus of mice. Our findings therefore highlight the potential of ART to be harmful to the brain and as such these drugs may contribute to the development of HIV-associated neurocognitive disorder (HAND).

Rosmarinic acid reverses the deleterious effects of repetitive stress and tat protein.

Human immunodeficiency virus type 1 (HIV) has infected more than 40 million people worldwide and is associated with central nervous system (CNS) disruption in at least 30% of these persons. The use of highly active antiretroviral therapy (HAART) has significantly reduced the systemic immunopathology associated with HIV, but the occurrence of neurological disorders continues to be reported in notable numbers. The present study evaluated the potential of rosmarinic acid to reverse the detrimental effects of an intracerebral injection of the viral protein tat. Control and tat-injected rats were also subjected to repetitive restrain stress (RRS) for 28 days, 6 h per day, to investigate whether subsequent stress exposure would worsen the effects of tat. 14 days after the initiation of RRS, animals were treated with rosmarinic acid (10 mg/kg given intraperitoneally) daily until the end of the stress exposure period. We assessed locomotor activity and anxiety-like behavioral changes. We also measured plasma corticosterone levels and quantified the expression of mineralocorticoid receptors (MR), glucocorticoid receptors (GR) and brain-derived neurotrophic factor (BDNF) in the hippocampus. Rosmarinic acid attenuated anxiety-like behavior induced by tat and stress, reduced plasma corticosterone levels and increased the expression of hippocampal GR, MR and BDNF when compared to controls. These results suggest that rosmarinic acid may reverse the anxiogenic effect of HIV-1 viral protein tat and related stress through modulation of the hypothalamic-pituitary-adrenal axis and hippocampal neurotrophic factor levels.

Multiproduct Resin Reuse for Clinical and Commercial Manufacturing-Methodology and Acceptance Criteria.

Chromatography resins used for purifying biopharmaceuticals are generally dedicated to a single product. In good manufacturing practice (GMP) facilities that manufacture a limited amount of any particular product, this practice can result in the resin being used for a fraction of its useful life. A methodology for extending resin reuse to multiple products is described. With this methodology, resin and column performance, product carryover, and cleaning effectiveness are continually monitored to ensure that product quality is not affected by multiproduct resin reuse (MRR). Resin and column performance is evaluated in terms of (a) system suitability parameters, such as peak-shape and transition, and height equivalent theoretical plate (HETP) data; (b) key operating parameters, such as flow rate, inlet pressure, and pressure drop across the column; and (c) process performance parameters, such as impurity profiles, product quality, and yield. Historical data are used to establish process capability limits (PCLs) for these parameters. Operation within the PCLs provides assurance that column integrity and binding capacity of the resin are not affected by MRR.Product carryover defined as the carryover of the previously processed product (A) into a dose of the subsequently processed product (B) (COA→B), should be acceptable from a predictive patient safety standpoint. A methodology for determining COA→B from first principles and setting acceptance limits for cleaning validation is described.Cleaning effectiveness is evaluated by performing a blank elution run after inter-campaign cleaning and prior to product changeover. The acceptance limits for product carryover (COA→B) are more stringent for MRR than for single-product resin reuse. Thus, the inter-campaign cleaning process should be robust enough to consistently meet the more stringent acceptance limits for MRR. Additionally, the analytical methods should be sensitive enough to adequately quantify the concentration of the previously processed product (A) and its degradants in the eluent.General considerations for designing small-scale chromatographic studies for process development are also described. These studies typically include process-cycling runs with multiple products followed by viral clearance studies with a panel of model viruses. Small-scale studies can be used to optimize cleaning parameters, predict resin performance and product quality, and estimate the number of multiproduct purification cycles that can be run without affecting product quality. The proposed methodology is intended to be broadly applicable; however, it is acknowledged that alternative approaches may be more appropriate for specific scenarios.LAY ABSTRACT: Chromatography resins used for purifying biopharmaceuticals are generally dedicated to a single product. In good manufacturing practice (GMP) facilities that make a limited amount of any particular product, this practice can result in the resin being used for a fraction of its useful life. A methodology for extending resin reuse to multiple products is described. With this methodology, resin and column performance, product carryover, and cleaning effectiveness are continually monitored to ensure that product quality is not affected by multiproduct resin reuse.General considerations for designing small-scale chromatographic studies for process development are described. These studies typically include process-cycling runs with multiple products followed by viral clearance studies with a panel of model viruses. Small-scale studies can be used to optimize cleaning parameters, predict resin performance and product quality, and estimate the number of multiproduct purification cycles that can be run without impacting product quality.The proposed methodology is intended to be broadly applicable; however, it is acknowledged that alternative approaches may be more appropriate for specific scenarios.