Neurogenic inflammation after traumatic brain injury and its potentiation of classical inflammation

Background: The neuroinflammatory response following traumatic brain injury (TBI) is known to be a key secondary injury factor that can drive ongoing neuronal injury. Despite this, treatments that have targeted aspects of the inflammatory pathway have not shown significant efficacy in clinical trials. Main body: We suggest that this may be because classical inflammation only represents part of the story, with activation of neurogenic inflammation potentially one of the key initiating inflammatory events following TBI. Indeed, evidence suggests that the transient receptor potential cation channels (TRP channels), TRPV1 and TRPA1, are polymodal receptors that are activated by a variety of stimuli associated with TBI, including mechanical shear stress, leading to the release of neuropeptides such as substance P (SP). SP augments many aspects of the classical inflammatory response via activation of microglia and astrocytes, degranulation of mast cells, and promoting leukocyte migration. Furthermore, SP may initiate the earliest changes seen in blood-brain barrier (BBB) permeability, namely the increased transcellular transport of plasma proteins via activation of caveolae. This is in line with reports that alterations in transcellular transport are seen first following TBI, prior to decreases in expression of tight-junction proteins such as claudin-5 and occludin. Indeed, the receptor for SP, the tachykinin NK1 receptor, is found in caveolae and its activation following TBI may allow influx of albumin and other plasma proteins which directly augment the inflammatory response by activating astrocytes and microglia. Conclusions: As such, the neurogenic inflammatory response can exacerbate classical inflammation via a positive feedback loop, with classical inflammatory mediators such as bradykinin and prostaglandins then further stimulating TRP receptors. Accordingly, complete inhibition of neuroinflammation following TBI may require the inhibition of both classical and neurogenic inflammatory pathways.Frances Corrigan, Kimberley A. Mander, Anna V. Leonard and Robert Vin

Nevirapine-Based Antiretroviral Therapy Impacts Artesunate and Dihydroartemisinin Disposition in HIV-Infected Nigerian Adults.

Background. Nevirapine- (NVP-) based antiretroviral therapy (ART) and artesunate-amodiaquine are frequently coprescribed in areas of HIV and malaria endemicity. We explored the impact of this practice on artesunate and dihydroartemisinin pharmacokinetics. Methods. We conducted a parallel-group pharmacokinetic comparison between HIV-infected patients receiving NVP-based ART (n = 10) and ART-naive controls (n = 11). Artesunate-amodiaquine 200/600 mg was given daily for three days. Measurement of drug concentrations occurred between 0 and 96 hours after the final dose. Pharmacokinetic parameters were determined using noncompartmental analysis. Results. Comparing the NVP group to controls, clearance of artesunate was reduced 50% (1950 versus 2995 L/h; P = 0.03), resulting in a 45% increase in the AUC(0-96) (105 versus 69 ug(∗)hr/L; P = 0.02). The half-life of dihydroartemisinin was shorter in the NVP group (1.6 versuss 3.2 h; P = 0.004), but other dihydroartemisinin pharmacokinetic parameters were unchanged. A lower conversion of artesunate to dihydroartemisinin was observed in the NVP group (dihydroartemisinin: artesunate AUC(0-96) = 5.6 versuss 8.5 in NVP and control groups, respectively, P = 0.008). Conclusion. Although NVP-containing ART impacted some pharmacokinetic parameters of artesunate and dihydroartemisinin, overall exposure was similar or better in the NVP group

Disposition of amodiaquine and desethylamodiaquine in HIV-infected Nigerian subjects on nevirapine-containing antiretroviral therapy.

OBJECTIVES: Artesunate plus amodiaquine is used for malaria treatment in regions with overlapping HIV endemicity. Co-administration of artesunate/amodiaquine with antiretroviral therapy (ART) may result in drug-drug interactions, but minimal data exist. This study evaluated the impact of nevirapine-based ART, containing a backbone of zidovudine and lamivudine, on the disposition of amodiaquine and its active metabolite, desethylamodiaquine (DEAQ). METHODS: This was an open-label, parallel-group pharmacokinetic comparison between HIV-infected, adult subjects receiving steady-state nevirapine-based ART (n = 10) and ART-naive subjects (control group, n = 11). All subjects received a loose formulation of artesunate/amodiaquine (200/600 mg) daily for 3 days, with serial pharmacokinetic sampling over 96 h following the final dose of artesunate/amodiaquine. Amodiaquine and DEAQ were quantified using a validated HPLC method with UV detection. Pharmacokinetic parameters were determined using standard non-compartmental methods. RESULTS: Exposures to both amodiaquine and DEAQ were significantly lower in the nevirapine-based ART group compared with the control group (amodiaquine AUC₀₋₂₄ 145 versus 204 ng·h/mL, P = 0.02; DEAQ AUC₀₋₉₆ 14,571 versus 21,648 ng·h/mL, P < 0.01). The AUCDEAQ/AUC(amodiaquine) ratio was not different between groups (ART group 116 versus control group 102, P = 0.67). CONCLUSIONS: Subjects on nevirapine-based ART had lower exposure to both amodiaquine and DEAQ (28.9% and 32.7%, respectively). Consequently, this may negatively impact the effectiveness of artesunate/amodiaquine in HIV-infected individuals on this ART combination

The Nigeria Parkinson Disease Registry: Process, Profile, and Prospects of a Collaborative Project

BACKGROUND: Clinical disease registries are useful for quality improvement in care, benchmarking standards, and facilitating research. Collaborative networks established thence can enhance national and international studies by generating more robust samples and credible data and promote knowledge sharing and capacity building. This report describes the methodology, baseline data, and prospects of the Nigeria Parkinson Disease Registry. METHODS: This national registry was established in November 2016. Ethics approval was obtained for all sites. Basic anonymized data for consecutive cases fulfilling the United Kingdom Parkinson's Disease Brain Bank criteria (except the exclusion criterion of affected family members) are registered by participating neurologists via a secure registry website (www.parkinsonnigeria.com) using a minimal common data capture format. RESULTS: The registry had captured 578 participants from 5 of 6 geopolitical zones in Nigeria by July 2019 (72.5% men). Mean age at onset was 60.3 ± 10.7 years; median disease duration (interquartile range) was 36 months (18–60.5 months). Young‐onset disease (<50 years) represented 15.2%. A family history was documented in 4.5% and 7.8% with age at onset <50 and ≥ 50, respectively. The most frequent initial symptom was tremor (45.3%). At inclusion, 93.4% were on treatment (54.5% on levodopa monotherapy). Per‐capita direct cost for the registry was $3.37. CONCLUSIONS: This is the first published national Parkinson's disease registry in sub‐Saharan Africa. The registry will serve as a platform for development of multipronged evidence‐based policies and initiatives to improve quality of care of Parkinson's disease and research engagement in Nigeria

Maternal and neonatal outcomes after caesarean delivery in the African Surgical Outcomes Study: a 7-day prospective observational cohort study.

BACKGROUND: Maternal and neonatal mortality is high in Africa, but few large, prospective studies have been done to investigate the risk factors associated with these poor maternal and neonatal outcomes. METHODS: A 7-day, international, prospective, observational cohort study was done in patients having caesarean delivery in 183 hospitals across 22 countries in Africa. The inclusion criteria were all consecutive patients (aged ≥18 years) admitted to participating centres having elective and non-elective caesarean delivery during the 7-day study cohort period. To ensure a representative sample, each hospital had to provide data for 90% of the eligible patients during the recruitment week. The primary outcome was in-hospital maternal mortality and complications, which were assessed by local investigators. The study was registered on the South African National Health Research Database, number KZ_2015RP7_22, and on ClinicalTrials.gov, number NCT03044899. FINDINGS: Between February, 2016, and May, 2016, 3792 patients were recruited from hospitals across Africa. 3685 were included in the postoperative complications analysis (107 missing data) and 3684 were included in the maternal mortality analysis (108 missing data). These hospitals had a combined number of specialist surgeons, obstetricians, and anaesthetists totalling 0·7 per 100 000 population (IQR 0·2-2·0). Maternal mortality was 20 (0·5%) of 3684 patients (95% CI 0·3-0·8). Complications occurred in 633 (17·4%) of 3636 mothers (16·2-18·6), which were predominantly severe intraoperative and postoperative bleeding (136 [3·8%] of 3612 mothers). Maternal mortality was independently associated with a preoperative presentation of placenta praevia, placental abruption, ruptured uterus, antepartum haemorrhage (odds ratio 4·47 [95% CI 1·46-13·65]), and perioperative severe obstetric haemorrhage (5·87 [1·99-17·34]) or anaesthesia complications (11·47 (1·20-109·20]). Neonatal mortality was 153 (4·4%) of 3506 infants (95% CI 3·7-5·0). INTERPRETATION: Maternal mortality after caesarean delivery in Africa is 50 times higher than that of high-income countries and is driven by peripartum haemorrhage and anaesthesia complications. Neonatal mortality is double the global average. Early identification and appropriate management of mothers at risk of peripartum haemorrhage might improve maternal and neonatal outcomes in Africa. FUNDING: Medical Research Council of South Africa.Medical Research Council of South Africa