Feasibility study to evaluate capabilities for conducting psychiatric clinical research within the Rwandan mental healthcare system.

OBJECTIVE: To evaluate the feasibility of conducting a large clinical trial within the Rwandan mental healthcare system that would establish the safety, efficacy and benefit of paliperidone palmitate once-monthly (PP1M) and once-every-3-months (PP3M) long-acting injectable formulations in adults with schizophrenia. STUDY DESIGN: An open-label, prospective feasibility study. SETTING/PARTICIPANTS: 33 adult patients with schizophrenia were enrolled at 3 sites across Rwanda. INTERVENTIONS: The study design included 3 phases of treatment: an oral run-in to establish tolerability to risperidone (1 week), lead-in treatment with flexibly dosed PP1M to identify a stable dose (17 weeks) and maintenance treatment with PP3M (24 weeks). PRIMARY AND SECONDARY OUTCOME MEASURES: Feasibility endpoints included compliance with governmental and institutional requirements, acceptable supply chain delivery and proper onsite administration of risperidone/PP1M/PP3M, adequate site infrastructure, adequate training of clinical staff and successful completion of study procedures and scales. A variety of study scales were administered to assess outcomes relevant to patients, caregivers, clinicians and payers in Rwanda and other resource-limited settings. RESULTS: This study was terminated early by the sponsor because certain aspects of study conduct needed to be addressed to maintain Good Clinical Practice requirements and meet regulatory standards. Results identified areas for improvement in study execution, including study governance, site infrastructure, study preparation and conduct of procedures, study budget and study assessments. Despite the identification of areas in need of adjustment, none of these limitations were considered insurmountable. CONCLUSIONS: This work was designed to strengthen global research in schizophrenia by building the capacity of researchers to prepare and conduct pharmaceutical trials in resource-limited settings. Although the study was ended early, modifications motivated by the results will facilitate the successful design and completion of more comprehensive studies, including an ongoing, follow-up interventional trial of PP1M/PP3M in a larger population of patients in Rwanda. TRIAL REGISTRATION NUMBER: NCT03713658.

Co-creation and Evaluation of Nationwide Remote Training Service for Mental Health Education of Community Health Workers in Rwanda.

Objective: Johnson & Johnson Global Public Health and the Ministry of Health of Rwanda strengthened the mental health awareness by providing an innovative, low-cost, easily accessible, and scalable remote training service (RTS) on mental health for Community Health Workers (CHWs). Methods: The RTS consisted of eight training modules shared via simple feature phones over a 4-week period. Quiz questions and baseline/endline assessments were included to assess the feasibility and acceptability of the training platform, the knowledge and self-confidence gained by the CHWs, and prospects for the sustainability of the platform. Results: Ninety-three percent of the CHWs completed at least four of the eight training modules, and 42% of the CHWs improved with a higher end score. The training content was considered interesting, easy to understand, and helpful to intervene appropriately to refer patients with signs of mental illness to a hospital and to provide community and family education on mental health topics. Conclusion: The RTS is feasible and acceptable for the delivery of mental health training on a large scale and contributed to strengthening the capacity in delivering mental health care at community level.

Novel, broad-spectrum anticonvulsants containing a sulfamide group: pharmacological properties of (S)-N-[(6-chloro-2,3-dihydrobenzo[1,4]dioxin-2-yl)methyl]sulfamide (JNJ-26489112).

Broad-spectrum anticonvulsants are of considerable interest as antiepileptic drugs, especially because of their potential for treating refractory patients. Such "neurostabilizers" have also been used to treat other neurological disorders, including migraine, bipolar disorder, and neuropathic pain. We synthesized a series of sulfamide derivatives (4-9, 10a-i, 11a, 11b, 12) and evaluated their anticonvulsant activity. Thus, we identified promising sulfamide 4 (JNJ-26489112) and explored its pharmacological properties. Compound 4 exhibited excellent anticonvulsant activity in rodents against audiogenic, electrically induced, and chemically induced seizures. Mechanistically, 4 inhibited voltage-gated Na(+) channels and N-type Ca(2+) channels and was effective as a K(+) channel opener. The anticonvulsant profile of 4 suggests that it may be useful for treating multiple forms of epilepsy (generalized tonic-clonic, complex partial, absence seizures), including refractory (or pharmacoresistant) epilepsy, at dose levels that confer a good safety margin. On the basis of its pharmacology and other favorable characteristics, 4 was advanced into human clinical studies.

Novel, broad-spectrum anticonvulsants containing a sulfamide group: advancement of N-((benzo[b]thien-3-yl)methyl)sulfamide (JNJ-26990990) into human clinical studies.

In seeking broad-spectrum anticonvulsants to treat epilepsy and other neurological disorders, we synthesized and tested a group of sulfamide derivatives (4a-k, 5), which led to the clinical development of 4a (JNJ-26990990). This compound exhibited excellent anticonvulsant activity in rodents against audiogenic, electrically induced, and chemically induced seizures, with very weak inhibition of human carbonic anhydrase-II (IC(50) = 110 microM). The pharmacological profile for 4a supports its potential in the treatment of multiple forms of epilepsy, including pharmacoresistant variants. Mechanistically, 4a inhibited voltage-gated Na(+) channels and N-type Ca(2+) channels but was not effective as a K(+) channel opener. The pharmacokinetics and metabolic properties of 4a are discussed.

Carbonic anhydrase inhibition. Insight into the characteristics of zonisamide, topiramate, and the sulfamide cognate of topiramate.

Some useful therapeutic agents inhibit certain carbonic anhydrase (CA) isozymes to varying degrees. We have conducted enzyme kinetics studies in a 4-nitrophenyl acetate (4-NPA) hydrolysis assay with the marketed antiepileptic drugs topiramate (1) and zonisamide (2) to determine if their full inhibition of human CA-II and CA-I requires extended preincubation conditions. We found that neither 1 nor 2 requires appreciable preincubation with either enzyme to manifest full inhibitory activity. We also examined the sulfamide cognate of topiramate (3) to characterize its CA inhibitory activity, and confirmed that it is a very weak inhibitor, unlike 1 or 2. In a CO(2) hydration assay, 3 behaved as a very weak, partial inhibitor of CA-II and CA-I. We conclude that topiramate (1), zonisamide (2), and sulfamide 3 do not require extended exposure to human CA-I or CA-II to manifest full inhibitory activity (4-NPA assay).

Carbonic anhydrase-II inhibition. what are the true enzyme-inhibitory properties of the sulfamide cognate of topiramate?

The marketed drug topiramate ( 1) is a moderate inhibitor of carbonic anhydrase-II (CA-II) ( K i or K d = 0.3-0.6 microM), whereas sulfamide cognate 2 is a comparatively weak inhibitor ( K i or K d = 25-650 microM). From an X-ray cocrystal structure of 2.CA-II, Winum et al. ( J. Med. Chem. 2006, 49, 7024) proposed that an adverse steric interaction between the C8 methyl group in 2 and Ala-65 of CA-II is responsible for the diminished CA-II inhibitory potency of 2. We performed a straightforward test of this Ala-65 effect by synthesizing and examining ligand 3, which lacks the offending (pro- S or C8) methyl substituent in 2. We also prepared and evaluated related sulfamides 5, 7, and 9. In a CA-II inhibition assay (4-nitrophenyl acetate), the K i for 3 was approximately 300 microM, indicating very weak inhibition, close to that for 2 (4NPA, K i = 340 microM). In a CA-II binding assay (ThermoFluor), the K d for 3 was >57 microM, indicating very weak binding, lower than the affinity of 2 ( K d = 25 microM). Our results draw into question the proposed steric interaction between the C8 methyl of 2 and Ala-65 of CA-II.

Reduction of dominant or submissive behaviors as models for antimanic or antidepressant drug testing: technical considerations.

Technical variants of mania and depression models that were based on dominant-submissive relationships (DSR) have been analyzed and compared in the present paper. In these paradigms, one animal of a pair developed the behavioral trait of dominance while the other submissiveness in a food competition test after repeated interactions in a specially designed apparatus. Data collection methods and timelines have been compared in variants of the DSR-based models. In addition, different selection criteria to assign dominant or submissive status to animals and two different scoring systems were evaluated. The importance of the selection criteria for DSR stability has been emphasized. Our data showed that (1) only animals selected with the strict criteria form clear dominant and submissive relationships that hold throughout the study period, (2) submissive animals were influenced by fluoxetine and dominant animals were influenced by sodium valproate similarly in pairs scored by human observer and by a video-tracking system. These studies indicate that the model variant using stringent selection criteria and automatic scoring was the most reliable for use in depression-related studies.

Examination of two independent kinetic assays for determining the inhibition of carbonic anhydrases I and II: structure-activity comparison of sulfamates and sulfamides.

Enzyme inhibition assays often require deviations from physiological conditions. For carbonic anhydrases, procedures involving native CO(2) and non-native substrates have been used. We compared a native and a non-native substrate in the context of inhibition of human carbonic anhydrases I and II by examining various sulfamate and sulfamide compounds in two kinetic assays: hydration of CO(2) and hydrolysis of 4-nitrophenylacetate. For carbonic anhydrase II, the two assays consistently generated similar K(i) values, with the relative difference between the assays never exceeding 2.5-fold. However, for carbonic anhydrase I there was more variability between the two assays, with K(i) values for three compounds differing by more than 2.5-fold, up to eightfold. In the CO(2) hydration assay, some sulfamates and sulfamides exhibited mixed kinetics or partial inhibition. Our results indicate that K(i) or K(d) values from carbonic anhydrase assays involving non-native substrates should be confirmed by assays that use CO(2) (or HCO), to establish pharmacological relevance. From structure-activity comparisons, the sulfamate is more effective than the sulfamide in inhibiting carbonic anhydrase I and II, but the sulfamate does not confer selectivity. In contrast, the sulfonamide confers selectivity for carbonic anhydrase I (10- to 30-fold). Selectivity for carbonic anhydrase II occurred with the substituted fructose moiety, especially the d-enantiomer (>100-fold).

Inhibition of carbonic anhydrase-II by sulfamate and sulfamide groups: an investigation involving direct thermodynamic binding measurements.

This paper examines the relative effectiveness of bioisosteric sulfamate and sulfamide derivatives for inhibition of human carbonic anhydrase-II (CA-II) by using a direct binding assay based on the ThermoFluor method (Matulis et al. Biochemistry 2005, 44, 5258). Compounds 1-10, which represent five cognate sulfamate/sulfamide pairs, were studied by ThermoFluor to obtain binding affinities (K(a) values). The corresponding dissociation constants, K(d), provide an independent measure of CA-II activity relative to commonly used K(i) values from enzyme kinetics studies. There was a sizable difference in potency between the sulfamates and sulfamides, with the sulfamides being much less potent, by factors ranging from 25 (7/8) to 1,200 (3/4). These results are consistent with our recent report that sulfamides tend to be much weaker inhibitors of CA-II than their corresponding sulfamates (Maryanoff et al. J. Med. Chem. 2005, 48, 1941). Additionally, for arylsulfamides 10-12 the K(d) values determined by ThermoFluor and the K(i) values determined from enzyme kinetics are consistent. It appears that the sulfamide group is less suitable than the sulfamate group for obtaining potent inhibition of CA-II.

Activity-dependent neurotrophic factor-9 and NAP promote neurite outgrowth in rat hippocampal and cortical cultures.

Activity-dependent neurotrophic factor (ADNF) is a novel, femtomolar-acting, glial-derived polypeptide (14 kDa) known to protect neurons from a variety of toxic insults. The active site for ADNF function is localized to a 9-amino-acid stretch (SALLRSIPA; ADNF-9). A few years later, a novel ADNF-9-like active peptide (NAPVSIPQ or NAP) was identified and shown to be expressed in the CNS and exhibit an activity profile similar to ADNF-9. Such studies suggest that ADNF-9 and NAP might function like other known neurotrophins and play a role in neural development and maintenance. The purpose of the present studies was to determine if ADNF-9 or NAP affects neurite outgrowth and synaptogenesis in rat hippocampal and cortical cultures. Using MAP2-FITC immunofluorescent labeling, we found that ADNF-9 and NAP promoted neurite outgrowth in a concentration-dependent manner, with maximal activity observed at femtomolar concentrations. Both peptides stimulated robust outgrowth in hippocampal cells (approximately 150% of control; p < 0.01) with a modest effect on cortical cells (approximately 20% of control; p < 0.05) similar to other known growth factors. However, the outgrowth-promoting effect was abolished in the absence of serum, suggesting that soluble factors might be necessary for the neurotrophic activity. Finally, we found that ADNF-9 and NAP increased synaptophysin expression in both rat hippocampal and cortical cultures. These results suggest that ADNF-9 and NAP might contribute to neuronal plasticity associated with development and repair after injury.

Comparison of sulfamate and sulfamide groups for the inhibition of carbonic anhydrase-II by using topiramate as a structural platform.

This paper examines the relative effectiveness of sulfamate and sulfamide groups for the inhibition of carbonic anhydrase-II (CA-II). Topiramate (1) and its sulfamide analogue 4, and 4,5-cyclic sulfate 6 and its sulfamide analogue 5, were compared for inhibition of human CA-II. A colorimetric assay, based on the pH shift that accompanies hydration of carbon dioxide, and an esterase assay were used. For these bioisosteric pairs, 1/4 and 6/5, the sulfamate compound was markedly more potent than its sulfamide counterpart. A similar, large difference in potency was also observed for the sulfamate/sulfamide pairs 14/15 and 16/17. These results indicate that the sulfamide moiety is not particularly suitable for obtaining potent carbonic anhydrase inhibition. A discussion of this structure-activity relationship with respect to the interactions of 1 and 6 with CA-II from published X-ray data is presented. A metabolic acidosis study was performed in rats with 1, 4, 6, and 2, and the results are discussed with respect to the degree of inhibition of CA-II in vivo.

Modulation by topiramate of AMPA and kainate mediated calcium influx in cultured cerebral cortical, hippocampal and cerebellar neurons.

The effect of the antiepileptic drug topiramate on Ca2+ uptake through (RS)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)propionate (AMPA) and kainate (KA) receptors was investigated in different cell culture systems consisting of neurons from the cerebral cortex, hippocampus, and cerebellum. Ca2+ influx was assayed using a fluorescent Ca2+ chelator to monitor changes in the intracellular Ca2+ concentration or cobalt staining to assess the effect of topiramate on Ca2+-permeable AMPA/KA receptors. In all types of neuronal cultures studied, AMPA and KA were found to elicit an influx of Ca2+ in a subset of the neuronal population. Topiramate, at concentrations of 30 and 100 microM, inhibited Ca2+ influx by up to 60%. Modulation of AMPA and KA-evoked Ca2+ influx may contribute to both the antiepileptic and neuroprotective properties of topiramate.