High rifampicin-resistant TB cure rates and prevention of severe ototoxicity after replacing the injectable by linezolid in early stage of hearing loss.

The short treatment regimen (STR) achieves a >80% cure in rifampicin-resistant tuberculosis (RR-TB) patients. However, ototoxicity induced by the injectable is a concern. This is the first study to evaluate the replacement of injectables by linezolid in patients with audiometry abnormalities at baseline or during the treatment.We conducted a retrospective cohort study of all RR-TB patients started on the STR between 2016 and June, 2019, in Niger. Patients underwent audiometry every 2 months in 2016 and every month since 2017.Of 195 patients, 16.9% (33 out of 195) received linezolid from the start (n=17), or switched from injectables to linezolid during treatment (n=16), based on audiometry abnormalities. In 2016, two patients developed severe ototoxicity despite switching to linezolid. Since 2017, no patient developed severe hearing loss or complete deafness. Severe haematological toxicity was observed in 18.1% (six out of 33) of patients on linezolid, none of which was life threatening. The use of linezolid was associated with severe but manageable adverse events (hazard ratio 8.9, 95% CI 2.5-31.5; p=0.001). A total of 90.9% (30 out of 33) of patients on a linezolid-containing STR were cured, and none experienced treatment failure. Three died, but not due to adverse events.Baseline and monthly audiometry monitoring and using linezolid after detection of hearing abnormalities appears effective to prevent severe ototoxicity, while keeping high treatment success and manageable adverse events.

An overview of chlorophenols as contaminants and their removal from wastewater by adsorption: A review.

In this review article, a significant number of published articles (over three decades) were consulted in order to provide comprehensive literature information about chlorophenols, their sources into the environment, classification, and toxicity, various wastewater treatment methods for their removal as well as the characteristics of their adsorption by various adsorbents. Organizing the scattered available information on a wide range of potentially effective adsorbents in the removal of chlorophenols is the principal objective of this article. Various adsorbents such as natural materials, waste materials from industries, agricultural by-products and biomass-based activated carbon in the removal of various chlorophenols have been compiled and discussed here. Crucial factors like temperature, solution pH, contact time and initial solution concentration are also reported and discussed here. The π-π dispersion interaction mechanism, hydrogen bonding formation mechanism, and the electron donor-acceptor complex mechanism were proposed for the chlorophenols adsorption onto various adsorbents with the help of current literature. Conclusions have been drawn proposing a few suggestions for future research on mitigating the effect of chlorophenols in the environment.

Correction: Improvements in properties of polybenzoxazine-based laser-induced graphene (LIG) by alloying with polyimide and modeling of production process.

[This corrects the article DOI: 10.1039/D3NA01026K.].

Improvements in properties of polybenzoxazine-based laser-induced graphene (LIG) by alloying with polyimide and modeling of production process.

Laser-induced graphene (LIG) is conventionally produced from polyimide among thermosetting polymer substrates, but its flexible nature limits its tremendous potential in applications where flexibility of the substrate is not desired. Interestingly, polybenzoxazine has also been found to have potential as a substrate in LIG production. However, aside from being brittle, it has inferior char residue and thermal stability relative to polyimide, which could result in the production of LIG with inferior properties. Thus, exploring possible improvements in the properties of the polybenzoxazine-based substrate and LIG by alloying with polybenzoxazine and polyimide is the major motivation of this study. First, the improvement in the toughness, char residue and thermal stability of polybenzoxazine by alloying with polyimide was explored. Second, the properties of a LIG obtained from the polybenzoxazine/polyimide alloy were studied. The electrical sheet resistivity, Raman spectra indices, structural morphologies, and crystal size of the neat polybenzoxazine and polybenzoxazine/polyimide alloy substrates were compared. The results reveal significant improvements in the electrical resistivity, structural morphology, and crystal size of the LIG. In addition, the improved polybenzoxazine/polyimide alloy substrate was used to optimize the operational parameters of the laser machine for the production of the LIG. LIG with a minimum electrical sheet resistivity of 3.61 Ω sq-1, multi-layer crystals as confirmed by Raman spectroscopic analysis, and a sponge-like highly porous structure was achieved with the optimum operational conditions in an ambient environment. Last, a quadratic model was found and validated to suitably define the production process. The study demonstrated an improvement in the property of a rigid polybenzoxazine-based LIG by alloying polybenzoxazine with polyimide for the first time.

Development of a laser induced graphene (LIG) and polylactic acid (PLA) shape memory polymer composite with simultaneous multi-stimuli response and deformation self-sensing characteristics.

This study presents the integration of laser-induced graphene (LIG) on a polylactic acid (PLA) substrate to create a novel shape memory polymer composite (SMPC) with multi-stimuli response and deformation self-sensing characteristics. The LIG was initially engraved on a commercial polyimide film and subsequently transferred to the PLA substrate through hot compression. Raman spectra analysis confirmed the successful engraving of the LIG, exhibiting the typical characteristic peaks. Durability tests revealed that the transferred LIG adhered well to the PLA substrate. Additionally, the transferred LIG demonstrated a sheet resistance of 40.3 Ω sq-1, which facilitated the electrical actuation of the LIG/PLA composite through Joule heating, allowing precise temperature control by manipulating the applied electrical power. An optimum electrical power of 0.95 W was identified to rapidly reach the actuation temperature without exceeding 80 °C. The study also demonstrated the LIG/PLA composite's responsiveness to infrared (IR) light, attributed to photothermal conversion behavior of LIG. An optimum IR intensity of 85 mW cm-2 was established for reaching the actuation temperature without surpassing 80 °C. This multi-stimulus functionality was achieved alongside real-time monitoring of the shape recovery ratio, enabled by the piezoresistive properties of LIG, which allowed for recording electrical resistance changes during recovery. This approach eliminates the need for external components and offers a straightforward fabrication process. The ability to actuate and sense deformation using a single, integrated LIG pattern opens new opportunities for developing advanced, multi-responsive, and self-sensing shape memory polymer composites.

Development of a magnified sunlight responsive shape memory bio-composite: effects of titanium nitride (TiN) nanoparticles on a bio-based benzoxazine/epoxy copolymer.

This study uniquely explored the effects of loading titanium nitride (TiN) nanoparticles in a bio-based benzoxazine/epoxy copolymer on the shape memory performance of the resulting composite using normal and magnified sunlight irradiation stimuli scenarios. Additionally, the effects of loading the TiN nanoparticles in the copolymer on light absorbance capacity, thermal stability, visco-elastic properties, and tensile properties of the composites were analysed. Results reveal that the different loading amounts (1 to 7 wt%) of TiN dispersed well within the copolymer matrix and produced excellent composite samples (TiN-1(wt%), TiN-3(wt%), TiN-5(wt%), and TiN-7(wt%)). Interestingly, the obtained samples were found to exhibit improved light absorbance in the wavelength range of 200-900 nm, giving the samples greater sunlight absorbing capacity. Moreover, the thermal stability of the composites increases with an increase in the loading amount; for instance, the initial degradation temperature increased from 316 °C to 324 °C. Meanwhile, visco-elastic and tensile properties increased and reached the optimum for TiN-5(wt%), where 3.1 GPa and 10.4 MPa were recorded as storage modulus and tensile stress, respectively. Consequent to these improvements in the properties of the composites, the shape memory performance of the composites was positively impacted. For instance, average shape fixity ratio, shape recovery ratio, and recovery time of 95%, 96%, and 38 seconds, respectively, were achieved with TiN-7(wt%), which represents 19%, 17%, and 38% improvements, respectively, compared to when the neat copolymer (TiN-0(wt%)) was used using magnified sunlight irradiation stimulus. Overall, this finding provides the basis for the utilization of magnified sunlight irradiation stimulus to achieve excellent shape memory performance with TiN-filled polymer composites.

Toughening Polylactic Acid with Ultrafine Fully Vulcanized Powdered Natural Rubber Graft-Copolymerized with Poly(styrene-co-acrylonitrile): Tailoring the Styrene-Acrylonitrile Ratio for Enhanced Interfacial Interactions.

This study investigated the sustainable toughening of polylactic acid (PLA) by incorporating ultrafine fully vulcanized powdered natural rubber graft-copolymerized with poly-styrene-co-acrylonitrile (UFPNR-SAN). We investigated the effect of the styrene-to-acrylonitrile ratio (ST:AN) used during the grafting process on the final UFPNR-SAN compatibility with PLA. The ST:AN ratio was systematically varied during the grafting reaction to prepare UFPNR-SAN with a range of different surface energies. The ST:AN ratio of 4:1 showed the highest compatibility with the PLA matrix, attributed to optimal interfacial interactions and improved dispersion, as indicated by contact angle measurements and SEM observations. This resulted in a remarkable toughening of the PLA/UFPNR-SAN composite. For instance, an obvious fully ductile behavior without crack formation and flexural strain of around 17.5% against 5% of the neat PLA was recorded. In addition, 3.5 times improvement in the impact strength of the composite at 25 wt% dosage of the UFPNR-SAN was also achieved without compromising thermal properties. Overall, this study established the suitable ST:AN ratio on the grafting onto natural rubber to enhance interfacial interactions with PLA and its effects on the properties of the resulting PLA/UFPNR-SAN bio-based composite.

Definitive outcomes in patients with rifampicin-resistant tuberculosis treated in Niger from 2012 to 2019: A retrospective cohort study.

BACKGROUND: Outcomes of retreatment for rifampicin-resistant tuberculosis (RR-TB) are rarely reported. We report 'definitive outcomes' after a cascade approach to RR-TB treatment. After a bacteriologically adverse outcome for the 9-months fluoroquinolone-based Short Treatment Regimen (STR), patients were retreated with a bedaquiline-based regimen (BDQ-regimen). METHODS: A Retrospective cohort study of RR-TB patients treated with the STR during 2012-2019 and retreated with a BDQ-regimen in case of failure or relapse was conducted. Definitive relapse-free cure took into account BDQ-regimen outcomes. RESULTS: Of 367 patients treated with the STR, 20 (5.4%) experienced failure or relapse. Out of these 20 patients, 14 started a BDQ-regimen, of whom none experienced failure or relapse. Definitive end of treatment outcomes of STR after revising with third-line BDQ-regimen outcomes, 84.7% (311/367) were cured relapse-free, 10.6% (39/367) died during treatment and 3.0% (11/367) were lost to follow-up during treatment with either the STR or BDQ-regimen. Six patients (1.6%; 6/367) with STR failure/relapse died before starting a BDQ-regimen. No patient had definitive treatment failure or relapse and remained without treatment. CONCLUSIONS: If fluoroquinolone resistance is excluded or rare, it is beneficial to use fluoroquinolone as the core drug for a first RR-TB treatment regimen and to safeguard bedaquiline for those in need of retreatment.

[Drug-resistant pulmonary tuberculosis at Maradi Regional Hospital Center, Niger (2014-2018)]. / Tuberculose pulmonaire résistante à la rifampicine au Centre Hospitalier régional de Maradi, Niger (2014-2018).

Aim of study: To describe the clinical, therapeutic and evolutionary profile of patients followed for rifampicin-resistant pulmonary tuberculosis (RR-TB) at the Regional Hospital Centre (RHC) of Maradi (Niger) from 2014 to 2018. Methods: We conducted a retrospective and descriptive study based on the records of patients followed for Multidrug-resistant tuberculosis (MDR-TB) between January 1, 2014 and June 30, 2018 at the resistant tuberculosis management unit in Maradi (Niger). This unit is located within the RHC of Maradi and has a capacity of 20 beds in 4 wards. It receives patients with tuberculosis resistant to first-line anti-tuberculosis drugs. In this study, patients diagnosed with RR-TB by genotypic (GeneXpert MTB/RIF) or phenotypic (culture) testing were included. We excluded from this study: patients previously treated for more than 1 month with second-line anti-TB drugs; patients with resistance to second-line injectables (SLI) and/or fluoroquinolones (FQ); patients with an electrocardiogram QTc greater than 500 ms (the corrected QT (QTc) estimates the QT interval at a rate of 60 beats per second); cases of atypical mycobacteriosis detected by phenotypic testing.Patients were previously on 2RHZE/4RH prior to the discovery of resistance. The treatment protocol for resistant TB was as follows: 4KmMfxPtoCfzHZE/5MfxCfzZE (The second-line injectable was replaced by Lzd in case of initial or treatment-emergent deafness). HIV co-infected patients received, in addition to anti-tuberculosis drugs, antiretrovirals and cotrimoxazole in preventive doses. Results: A total of 80 patients were included in the present study (70 males and 10 females, mean age 34.4 years with extremes ranging from 18 to 71 years). Patients aged 18-35 years accounted for more than half. Patients with primary treatment failure were the most frequent type (36%) followed by patients with retreatment failure (24%) and patients with retreatment relapse (17%). It should be noted that 77 patients (96%) were previously treated for TB and only 3 patients (4%) were new cases. The majority of patients (70%) had a Body mass index of less than 18 kg/m2. 7.5% of patients were HIV positive, one was diabetic, 52% of the patients had grade 2 radiological lesions. Grade 1 deafness was noted at the beginning of treatment in 3%. A third of patients (36%) were primary treatment failures. The treatment protocol was as follows: 4KmMfxPtoCfzHZE/5MfxCfzZE. Only 1 patient had a positive culture at the end of the 4th month of treatment. Most of the patients had experienced adverse events, mainly digestive, with vomiting being the most common. The therapeutic success rate was 88%. We noted 10% of deaths, 1% of therapeutic failure and 1% of lost to follow-up.Six months after treatment, 48 patients (60%) were smear negative and 43 (54%) were culture negative. In 32 patients (40%), the smear was not performed and culture was not performed in 37. Conclusion: The short treatment regime gives satisfactory results in the absence of resistance to fluoroquinolones, with rare adverse effects. In Niger, further efforts should be made to minimize the delay in diagnosis which is responsible for most deaths during treatment. A centre could usefully be designated to organize "TB consiliums" allowing any practitioner to submit difficult cases of MDR-TB.

Evaluation of the resistance of Mycobacterium tuberculosis to rifampicin at the regional hospital center of Maradi, Niger Republic.

Background: According to the World Health Organization (WHO) data, 600,000 cases of rifampicin-resistant tuberculosis (TB) have been reported worldwide, including 490,000 cases of multidrug-resistant TB. Thus, through the present study, we proposed to evaluate the resistance of Mycobacterium tuberculosis to rifampicin in the regional hospital of Maradi. Methods: Our study involved 887 sputum samples that were GeneXpert tested from January 2016 to December 2020. These data were collected from the laboratory records of the Maradi Regional Hospital and analyzed with SPSS and Excel 2013 software. Results: In total, more than half of the patients were male, i.e., a sex ratio of 3.03. The average age was 41 years. The rate of detection of M. tuberculosis by GeneXpert was 42% and the frequency of resistance to rifampicin was 20%. However, treatment failure and relapse were associated with this monoresistance in 53.95% and 30.26% of cases, respectively. Conclusion: The present study shows a fairly high prevalence of rifampicin resistance in the Maradi region, corresponding to twice the WHO threshold. The vast majority of these cases presented either a therapeutic failure or a relapse. Urgent and effective actions must be taken to significantly reduce the rates of treatment failure and relapse to decrease the rate of monoresistance and thus avoid the emergence of multidrug-resistant strains.

Safety, effectiveness, and adherence of a short and all-oral treatment regimen for the treatment of rifampicin-resistant tuberculosis in Niger: a study protocol of a pragmatic randomised clinical trial with stratified block randomisation.

BACKGROUND: Rifampicin-resistant tuberculosis (RR-TB) treatment requires combination treatment, which frequently causes serious adverse events and globally results in not much more than 60% treatment success. In Niger, a high cure rate was obtained with a RR-TB treatment strategy based on a second-line injectable drug (SLID)-containing Short Treatment Regimen (STR), with linezolid replacing the SLID in patients with ototoxicity. Given the availability of novel anti-tuberculosis drugs, WHO recommends all-oral RR-TB treatment. Considering the high level of success with the Niger treatment strategy, it would only be justified to replace it in case robust evidence shows that the WHO all-oral bedaquiline/linezolid (BDQ/LZD)-containing STR (experimental arm) performs better than the Niger RR-TB treatment strategy, (control arm) in terms of safety, effectiveness and adherence. METHODS: A pragmatic randomised clinical trial (RCT) using stratified block randomisation, conducted between April 2021 and March 2024, prospectively enrols participants diagnosed with RR-TB in one of the four RR-TB units of the nation. Depending of the month in which patients are diagnosed with RR-TB, patients with FQ-susceptible RR-TB are enrolled in either the experimental arm or control arm. DISCUSSION: To increase the feasibility of conducting a RCT, embedded in routine activities of all Niger's RR-TB Units, we used a creative trial design. We randomised by monthly blocks, whereby the regimen used changes every month, using the month of RR-TB diagnosis as stratifying variable. This approach was deemed feasible for Niger's national tuberculosis programme, as it simplifies the work of the clinicians running the RR-TB units. Our creative design may serve as an example for other national programs. Findings will inform national and international RR-TB treatment guidelines, and will also strengthen the evidence-base on how to develop robust RR-TB treatment regimens. TRIAL REGISTRATION: Pan African Clinical Trial Register PACTR202203645724919 . Registered on 15 March 2022.

COVID-19 vaccines uptake: Public knowledge, awareness, perception and acceptance among adult Africans.

INTRODUCTION: The willingness of Africa's population to patronise the COVID-19 vaccines is critical to the efficiency of national immunisation programmes. This study surveys the views of adult African inhabitants toward vaccination and the possibility of participating or not participating in governments' efforts to get citizens vaccinated. METHOD: A cross-sectional online survey of adult Africans was undertaken from December 2020 to March 2021. Responses were anonymised. The Pearson Chi-square test was performed to determine whether or not there were any variations in knowledge, awareness, perception and acceptance of the COVID-19 vaccines among the participants. Binomial logistic regression was used to evaluate the factors associated with willingness to accept the COVID-19 vaccines and participate in immunisation programmes. RESULTS: The results indicate that COVID-19 vaccines are more likely to be used by adult Africans over the age of 18 who are largely technologically savvy (55 percent) if the vaccine is made broadly available. A total of 33 percent of those who responded said they were unlikely to receive the vaccine, with another 15 percent stating they were undecided. Aside from that, we found that vaccine hesitancy was closely associated with socio-demographic characteristics such as age, gender, education and source of information. We also found that there were widespread conspiracies and myths about the COVID-19 vaccines. CONCLUSION: More than one-third of African adults who participated in the survey indicated they would not receive the COVID-19 vaccine, with majority of them expressing skepticisms about the vaccine's efficacy. It is possible that many of the people who would not be vaccinated would have an impact on the implementation of a COVID-19 immunisation programme that is meant for all of society. Majority of the respondents were unwilling to pay for the COVID-19 vaccines when made available. An awareness campaign should be focused on promoting the benefits of vaccination at the individual and population levels, as well as on taking preemptive actions to debunk misconceptions about the vaccines before they become further widespread.

Microcrystalline cellulose (MCC) based materials as emerging adsorbents for the removal of dyes and heavy metals - A review.

In an attempt to overcome such threats posed by water pollution, various processes ranging from physical, chemical as well as biological were applied to get rid of wastewater pollutants. The simplicity, high efficiency and cheapness of an adsorption process make it the most widely used among various other processes. Adsorbents with different properties were used in the adsorption process but this paper was focused on reviewing various articles published by numerous researchers on the isolation of microcrystalline cellulose (MCC), a popular carbohydrate polymer from lignocellulosic biomass and utilization of MCC based materials as effective adsorbents for the successful removal of dyes and heavy metals from synthetic wastewater. The sudden interest on MCC and MCC-based materials as adsorbents cannot be separated from their excellent properties such as renewability, biodegradability, biocompatibility, economic value, non-toxicity, high mechanical properties and surface area. Upon comparison with established adsorbents reported from literature, MCC-based materials performed excellently well in the adsorption of dyes and heavy metals with Langmuir isotherm and pseudo-second order reported mostly as the best fit models for the generated equilibrium and kinetic data, respectively pointing at the distribution of adsorption sites to be homogeneous as well as the formation of monolayer adsorbate on their surfaces. The various thermodynamic studies reported further revealed the adsorption processes of both dyes and heavy metals onto MCC-based materials to be entropy driven processes, spontaneous, and endothermic. Finally, future research was suggested to focus on optimization to enhance the performance of the MCC-based adsorbents, carrying out the adsorption on real wastewater instead of synthetic ones as well as expanding the range of adsorbates to include other contaminants such as chlorophenols, herbicides, pesticides and others in addition to dyes and heavy metals.

Juvenile dermatomyositis in a 14-year old Nigerian girl.

Juvenile Dermatomyositis is a rare idiopathic autoimmune and inflammatory myopathy and vasculopathy whose hallmarks are symmetrical proximal muscle weaknesses and a characteristic rash. Only few cases have been reported in West Africa subregion. We present a 14-year old Nigerian girl with clinical and histopathologic features of definitive juvenile dermatomyositis based on EULAR/ACR classification criteria but probable Juvenile dermatomyositis according to Bohan and Peter criteria. The patient had normal aspartate and alanine aminotransferase levels. Creatine kinase, Lactate dehydrogenase and aldolase which are not available in our center could not be evaluated. There was remarkable clinical improvement 3 weeks after the onset of systemic corticosteroid therapy. Our case highlights that relying on these normal enzyme values, especially where muscle biopsy and EMG are not available as is the case in most centers in developing countries, would have resulted in missed diagnosis using Bohan and Peter criteria.

Management of multidrug-resistant tuberculosis with shorter treatment regimen in Niger: Nationwide programmatic achievements.

BACKGROUND: In Niger, the Shorter Treatment Regimen (STR) has been implemented nationwide for rifampicin resistant tuberculosis (RR-TB), since 2008. No previous publication has shown the results from countrywide programmatic implementation using few exclusion criteria, nor exhaustively assessed the effect of initial resistance to companion drugs on outcomes. METHODS: The National Tuberculosis Programme and the Damien Foundation conducted a retrospective observational study to evaluate the management of RR-TB from 2008 to 2016. Baseline resistance to drugs was assessed phenotypically, complemented by screening the inhA, katG and pncA genes. Cured patients were followed-up for a period of one year after cure. FINDINGS: Among 1044 patients tested for rifampicin resistance, mainly previously treated patients, 332 were diagnosed with pulmonary RR/TB, 288 were enrolled on treatment and 255 started on STR. Six patients received a modified STR. Among 249 patients on standardised STR, 207 (83·1%) were cured relapse-free, eight (3·2%) had failure, 23 (9·2%) died, seven (2·8%) were lost to follow-up and four (1·6%) relapsed. The risk of unfavourable outcome was higher in patients with initial resistance to fluoroquinolones (aOR 20·4, 95%CI:5·6-74·6) and very severely underweight (aOR 3·9, 95%CI:1·5-10·1). Successful outcome was not affected by initial resistance to companion drugs. Serious ototoxicity was reported in eight patients (3·2%). INTERPRETATION: A comprehensive nationwide approach to multidrug-resistant tuberculosis management using the STR was feasible and successful. Outcomes were not affected by initial resistance to companion drugs. Our study confirms the effectiveness and safety of the STR. FUNDING: Damien Foundation and Institute of Tropical Medicine-Antwerp.

[Epidemiological, clinical and evolutionary profile of patients with tuberculosis at the Regional Hospital of Maradi, Republic of the Niger]. / Profil épidémiologique, clinique et évolutif des patients tuberculeux au Centre Hospitalier Régional (CHR) de Maradi, République du Niger.

INTRODUCTION: This study aimed to describe the epidemiological, clinical and evolutionary profile of patients treated for tuberculosis at the Regional Hospital of Maradi. METHODS: We conducted a retrospective, descriptive and analytical study of data from the medical records of patients treated for tuberculosis from 1st January 2015 to 31st December 2017. RESULTS: A total of 595 patients were followed (406 men, 68.24%, and 189 women, 31.76%) with a prevalence of 27,71%. The average age of patients was 42.3 ranging from 13 months to 85 years; 70.5% of these patients were from urban areas. Merchants represented 36.9% of the cases. Bacterial test was positive in 64.7% of cases. Functional signs included: coughing (99.5%), fever (79.5%), and chest pain. Pulmonary tuberculosis represented 78.7% of cases. Therapy was effective in 81.28% of cases. HIV prevalence was 13.6%, lethality 10.42% (40.4% of patients died from TB/HIV co-infection). CONCLUSION: Tuberculosis is a scourge in low-income countries, with 10.42% of deaths. HIV/AIDS infection has negatively contributed to these deaths during the study period. The search for comorbidities in any patient with tuberculosis should be systematic in order to improve their global management.