A review of the recent advances on Lassa fever with special reference to molecular epidemiology and progress in vaccine development

Lassa fever, a viral hemorrhagic fever caused by the Lassa virus (LASV), is endemic in West Africa and is associated with high morbidity and mortality. At least three of the four proposed seven lineages of LASV are found in Nigeria, where the multimammate rat, Mastomys natalensis, serves as the primary reservoir. Endemic countries report approximately 200,000 infections and 5,000 deaths annually, with Nigeria experiencing thousands of infections and hundreds of deaths including healthcare workers. The aim of this review is to provide scientific information for better understanding of the evolutionary biology, molecular epidemiology, pathogenesis, diagnosis, and prevention of Lassa fever in Nigeria and other endemic regions worldwide, which can lead to improved control efforts and reduce morbidity and mortality from recurrent epidemics. To achieve this aim, observational studies such as case series, cross-sectional and cohort studies published between December 2017 and September 2022 were searched for on various online databases including Google Scholar, Africa Journals Online (AJOL), Research Gates, PubMed, PMIC, NCDC, and WHO websites. Although the origin and evolutionary history, and the transmission dynamics of Lassa virus have been revealed through recent. molecular epidemiological studies, the factors that drive the evolution of the virus remain unclear. Genetic changes in the viral genome may have enabled the virus to adapt to humans. Diagnosis of Lassa fever has also advanced from basic serological tests to more sophisticated methods such as quantitative real time polymerase chain reaction (qRT-PCR) and sequencing, which are particularly useful for identifying outbreak strains. Several vaccines, including recombinant vesicular stomatitis virus (rVSV), virus-like particle (VLP), and DNA-based vaccines, have shown promise in animal models and some have progressed to phase 2 clinical trials. Preventing and controlling Lassa fever is critical to safeguard the health and well-being of affected communities. Effective measures such as rodent control, improved sanitation, and early detection and isolation of infected individuals are essential for reducing transmission. Ongoing research into the genetic and ecological factors that drive the evolution of Lassa virus is necessary to reduce the impacts of Lassa fever.

A review of the recent advances on Lassa fever with special reference to molecular epidemiology and progress in vaccine development

Lassa fever, a viral hemorrhagic fever caused by the Lassa virus (LASV), is endemic in West Africa and is associated with high morbidity and mortality. At least three of the four proposed seven lineages of LASV are found in Nigeria, where the multimammate rat, Mastomys natalensis, serves as the primary reservoir. Endemic countries report approximately 200,000 infections and 5,000 deaths annually, with Nigeria experiencing thousands of infections and hundreds of deaths including healthcare workers. The aim of this review is to provide scientific information for better understanding of the evolutionary biology, molecular epidemiology, pathogenesis, diagnosis, and prevention of Lassa fever in Nigeria and other endemic regions worldwide, which can lead to improved control efforts and reduce morbidity and mortality from recurrent epidemics. To achieve this aim, observational studies such as case series, cross-sectional and cohort studies published between December 2017 and September 2022 were searched for on various online databases including Google Scholar, Africa Journals Online (AJOL), Research Gates, PubMed, PMIC, NCDC, and WHO websites. Although the origin and evolutionary history, and the transmission dynamics of Lassa virus have been revealed through recent molecular epidemiological studies, the factors that drive the evolution of the virus remain unclear. Genetic changes in the viral genome may have enabled the virus to adapt to humans. Diagnosis of Lassa fever has also advanced from basic serological tests to more sophisticated methods such as quantitative real time polymerase chain reaction (qRT-PCR) and sequencing, which are particularly useful for identifying outbreak strains. Several vaccines, including recombinant vesicular stomatitis virus (rVSV), virus-like particle (VLP), and DNA-based vaccines, have shown promise in animal models and some have progressed to phase 2 clinical trials. Preventing and controlling Lassa fever is critical to safeguard the health and well-being of affected communities. Effective measures such as rodent control, improved sanitation, and early detection and isolation of infected individuals are essential for reducing transmission. Ongoing research into the genetic and ecological factors that drive the evolution of Lassa virus is necessary to reduce the impacts of Lassa fever

La fièvre de Lassa, une fièvre hémorragique virale causée par le virus de Lassa (LASV), est endémique en Afrique de l'Ouest et est associée à une morbidité et une mortalité élevées. Au moins trois des quatre lignées proposées de LASV se trouvent au Nigeria, où le rat multimammaire, Mastomys natalensis, sert de réservoir principal. Les pays endémiques signalent environ 200,000 infections et 5,000 décès par an, le Nigéria connaissant des milliers d'infections et des centaines de décès, y compris des travailleurs de la santé. L'objectif de cette revue est de fournir des informations scientifiques pour une meilleure compréhension de la biologie évolutive, de l'épidémiologie moléculaire, de la pathogenèse, du diagnostic et de la prévention de la fièvre de Lassa au Nigeria et dans d'autres régions endémiques du monde, ce qui peut conduire à des efforts de contrôle améliorés et réduire la morbidité et la mortalité des épidémies récurrentes. Pour atteindre cet objectif, des études observationnelles telles que des séries de cas, des études transversales et de cohorte publiées entre décembre 2017 et septembre 2022 ont été recherchées sur diverses bases de données en ligne, notamment Google Scholar, Africa Journals Online (AJOL), Research Gate, PubMed, PMIC, Sites Web du NCDC et de l'OMS. Bien que l'origine et l'histoire évolutive, ainsi que la dynamique de transmission du virus de Lassa aient été révélées par des études épidémiologiques moléculaires récentes, les facteurs qui déterminent l'évolution du virus restent flous. Des modifications génétiques du génome viral pourraient avoir permis au virus de s'adapter à l'homme. Le diagnostic de la fièvre de Lassa est également passé des tests sérologiques de base à des méthodes plus sophistiquées telles que la réaction quantitative en chaîne par polymérase en temps réel (qRTPCR) et le séquençage, qui sont particulièrement utiles pour identifier les souches épidémiques. Plusieurs vaccins, y compris le virus recombinant de la stomatite vésiculeuse (rVSV), les particules pseudo-virales (VLP) et les vaccins à base d'ADN, se sont révélés prometteurs dans des modèles animaux et certains ont progressé vers des essais cliniques de phase 2. La prévention et le contrôle de la fièvre de Lassa sont essentiels pour préserver la santé et le bien-être des communautés touchées. Des mesures efficaces telles que le contrôle des rongeurs, l'amélioration de l'assainissement et la détection et l'isolement précoces des personnes infectées sont essentielles pour réduire la transmission. Des recherches continues sur les facteurs génétiques et écologiques qui déterminent l'évolution du virus de Lassa sont nécessaires pour réduire les impacts de la fièvre de Lassa.

[Skin sensitisation profiles to inhalant allergens for patients in Tétouan city (North West of Morocco)]. / Profils de sensibilisation cutanée aux allergènes respiratoires des patients de la ville de Tétouan (Nord Ouest du Maroc).

The prevalence of respiratory allergies is increasing and is a serious global health problem. The objective of the study was to determine the prevalence of skin sensitization to inhalant allergens in patients consulting for respiratory allergy, to identify the main allergens involved and to evaluate the profile of skin prick-test reactivity related to sex, age and season. This retrospective study included 379 patients consulting during 2009-2012 in three private medical offices of Tetouan. Of the 379 patients, 39.6% were monosensitized and 60.4% polysensitized. The percentages of polysensitized patients were higher in patients exhibiting rhinoconjunctivitis and astma-rhinoconjunctivitis than in subjects with asthma. The prevalence of symptoms according to sex showed no significant difference (P=0.64). Regarding age, a significant difference was observed in the case of rhinoconjunctivitis (P<0.01), while asthma and asthma-rhinoconjunctivitis showed no significant difference. Sensitization to house dust mites was the most frequent followed by grasses, olives and Parietaria. The multiple correspondence analyses (ACM) showed that patients under 20-years of age with asthma and asthma-rhinoconjunctivitis profile are more associated with sensitization to mites during the spring and autumn. The 20-49-year age group was represented mainly by polysensitized patients with rhinoconjunctivitis. Sensitization to mites ranks first in Tetouan followed by the percentage of sensitized patients to grass pollen and olive. The ACM showed that the house dust mite asthma seems to affect more children and adolescents while the 20-49 year age of polysensitized group suffers significantly rhinoconjunctivitis.

[Interannual variation of the fungal spores of Tetouan (Northwest of Morocco) and their sporal calendar]. / Variation interannuelle des spores fongiques de Tétouan (Nord-Ouest du Maroc) et calendrier sporal.

THE AIM: The daily aeromycological monitoring of fungal spores in the city of Tetouan during the period 2009-2011, to determine their diversity, their predominance and their interannual and seasonal variation. MATERIAL AND METHODS: The spore sampling was undertaken using a Burkard volumetric spore trap. RESULTS: The outdoor environment of Tetouan showed a highest predominance of deuteromycetes, collected essentially in summer and autumn. This study illustrated a high diversity of the fungal spores, the most frequent accounting for more than 97 % of the airborne fungal flora, and are according to their abundance (Cladosporium followed by Basidiospores, Ustilago, Alternaria, Leptosphaeria, Aspergillaceae, Cunninghamella, Venturia, Uredospores, Pleospora, Arthrinium, Stemphylium, Torula, Oidium, Ascospores, Drechslera, Epicoccum, Teleutospores and Fusarium). Alternaria and Cladosporium showed a longer period of emission, and are present in the atmosphere throughout the year with the highest incidence for Alternaria in June and for Cladosporium in August. They exceeded the allergenic threshold value in the air of Tétouan during 22, 94 and 75 days in 2009, 2010 and 2011 respectively for Alternaria and during 16 days in 2009, 14 days in 2010 and 13 days in 2011 for Cladosporium. The correlation between the meteorological parameters and the fungal spores proved that the temperature (maximum, average and minimum), the relative humidity (maximum, average and minimum) and the precipitation influenced the presence of the fungal spores in the air. CONCLUSION: The exposition to airborne fungal spores varied between years depending on local climatic conditions and might cause health impacts on patients showing respiratory allergy.

Marginal longitudinal semiparametric regression via penalized splines.

We study the marginal longitudinal nonparametric regression problem and some of its semiparametric extensions. We point out that, while several elaborate proposals for efficient estimation have been proposed, a relative simple and straightforward one, based on penalized splines, has not. After describing our approach, we then explain how Gibbs sampling and the BUGS software can be used to achieve quick and effective implementation. Illustrations are provided for nonparametric regression and additive models.

Characteristics of intradialytic hypotension: experience of Agadir Center-Morocco.

We report in this retrospective study the experience of our hemodialysis (HD) center in the incidence of intradialytic hypotension (IDH) over 18 months. We first studied the demographic, clinical, biological and morphological data of our 52 HD patients and compared the characteristics of patients with frequent IDH and those without. We found that factors significantly associated with IDH include diabetes, left ventricular hypertrophy, impaired diastolic function, weight gain and high ultrafiltration rates. Despite these results, further larger studies are required to confirm them.

Wolfram syndrome.

Wolfram syndrome is a rare neurodegenerative and genetic disorder, which should be suspected in patients with young onset non-immune insulin dependent diabetes mellitus and optic atrophy. Patients are most likely to develop diabetes insipidus, deafness, urinary tract, and neurological abnormalities. 60% of the people with Wolfram syndrome die at age 35, usually due to central respiratory center failure following brain stem atrophy. Though there is no treatment to reverse the underlying mechanism of neurodegeneration, early diagnosis and adequate hormonal replacement could improve quality of life and survival.

Assessing changes in pupillary size in Rifian smokers of kif (Cannabis sativa L.).

Although the measurement of eye pupil variations is a common method in the only few cannabis effect research, there are no studies on short term effects of kif (Moroccan traditional preparation of cannabis) on eye pupil. The aim of the present paper is to present results about effect of a smoked kif preparation (Cannabis sativa L.) on pupil diameter variations after 30 mn. Two examiners measured the pupil diameter variations before and after kif smoking in 34 eyes of 17 volunteer-consumers in a dark closed room. Pupil diameter was estimated by Colvard pupillometer. Results reveal a significantly increase in pupil size post kif.

Predictions of tensile strength of binary tablets using linear and power law mixing rules.

There has recently been an increased interest in predicting the tensile strength of binary tablets from the properties of the individual components. In this paper, measurements are reported for tensile strength of tablets compressed from single-component and binary powder mixtures of lactose with microcrystalline cellulose (MCC), and lactose with two types of silicified microcrystalline cellulose (SMCC and SMCC-HD), which are different in compressibility. Measurements show the tensile strength increases with the relative density for single powders, and both with the relative density and the mass fraction of cellulose in the mixtures. It was also observed, for binary mixtures compacted at 50 and 150 MPa, that there was a slight variation in porosity with the mass fraction of celluloses. The predictions of the tensile strength of binary tablets from the characteristics of the single-components was analysed with the extended Ryshkewitch-Duckworth model by assuming both linear and power law mixing rules for the determination of the parameters "tensile strength at zero porosity and bonding capacity constant". As consequence, four models were analysed and compared with measurements using criteria based on the standard deviation from the mean values. Results showed a good prediction using a linear mixing rule combined with the power law. However, as the predictions of these models depend on the powders and the porosity range for the characterization of single-components, none of them can be systematically considered as being the best to predict binary behaviour from data for individual powders.

Seed germination and seedling growth of the Mexican sunflower Tithonia diversifolia (Compositae) in Nigeria, Africa

We studied seed germination and seedling growth of the Mexican sunflower Tithonia diversifolia in Nigeria. This involved the usage of some dormancy-releasing methods and the effect of some concentrations of three herbicide formulations on the young seedlings. Initial germination tests on fresh and stored seeds revealed a low percentage germination of less than 30%. The seeds of the weed exhibit dormancy. Subjecting the seeds to wet heat at 80 and 100 degrees C and light treatment terminated dormancy both in the fresh and stored seeds. Light greatly enhanced the germination percentage of seeds by about 70%. There was gradual increase in germination percentage with increase in storage period in dormancy-released seeds. The mean LAR (Leaf Area Ratio), NAR (Net Assimilation Rate) and RGR (Relative Growth Rate) are comparatively high in young seedlings. Concentrations of 0.5-2.0% of Gramoxone, Primextra and Galex are toxic to 1 month old seedlings. For eradication, the seedlings should be attacked at one month stage.

Se estudió la germinación y crecimiento de las plántulas del girasol mexicano Tithonia diversifolia. Se usaron métodos de periodo de latencia y germinación, y el efecto de varias concentraciones de tres herbicidas sobre las plántulas jóvenes. Las pruebas iniciales de germinación con semillas frescas y almacenadas revelaron un bajo porcentaje de germinación (30%). Las semillas de malezas permanecieron latentes. Al someter las semillas a tratamientos de calor húmedo de 80 y 100oC y luz se terminó con el periodo de latencia en las semillas frescas y en las almacenadas. La luz aumentó el porcentaje de germinación a cerca del 70%. Hubo un incremento gradual en el porcentaje de germinación en el periodo de almacenamiento en las semillas salidas de la latencia. Los promedios de cociente de área foliar, tasa neta de asimilación y tasa de crecimiento relativo son comparativamente altos en las plántulas jóvenes. Las concentraciones de 0.5-2.0% de Gramoxone, Primextra y Galex son tóxicas para las plántulas de un mes de edad.

Seed germination and seedling growth of the Mexican sunflower Tithonia diversifolia (Compositae) in Nigeria, Africa.

We studied seed germination and seedling growth of the Mexican sunflower Tithonia diversifolia in Nigeria. This involved the usage of some dormancy-releasing methods and the effect of some concentrations of three herbicide formulations on the young seedlings. Initial germination tests on fresh and stored seeds revealed a low percentage germination of less than 30%. The seeds of the weed exhibit dormancy. Subjecting the seeds to wet heat at 80 and 100 degrees C and light treatment terminated dormancy both in the fresh and stored seeds. Light greatly enhanced the germination percentage of seeds by about 70%. There was gradual increase in germination percentage with increase in storage period in dormancy-released seeds. The mean LAR (Leaf Area Ratio), NAR (Net Assimilation Rate) and RGR (Relative Growth Rate) are comparatively high in young seedlings. Concentrations of 0.5-2.0% of Gramoxone, Primextra and Galex are toxic to 1 month old seedlings. For eradication, the seedlings should be attacked at one month stage.

[Depressive disorders among epileptic patients attending a specialised outpatient clinic]. / Troubles dépressifs chez les patients épileptiques suivis au sein d'une unité de consultation spécialisée.

The overall prevalence of psychiatric disorders in epileptic patients is estimated between 19 and 62%. Depressive disorders may be the most common psychiatric disorders and the main reason for psychiatric hospitalisation and taking psychotropic drugs. The underdiagnosis and undertreatment of depressive disorders among epileptic patients represent a problem of considerable magnitude. The aim of the present study was to evaluate the prevalence of depressive disorders among patients with primary epilepsy and to determine the risk factors of the occurrence of the depressive illness. The survey was conducted in a outpatient epilepsy clinic in the Ibn Rochd University Hospital Centre in Casablanca. All patients with idiopathic or cryptogenic epilepsy aged 15 Years and above, were eligible, except for patients with severe physical and mental disabilities. Neurologists diagnosed the epilepsy based on clinical criteria with electroencephalograms data. The depressive disorders met a psychiatrist's evaluation of an ICD-10 criterion. Ninety-two subjects participated in the survey, 57.6% were men and the mean age was 30.3 +/- 10.8 Years. The epilepsy age of onset was 16.3 +/- 11.4 Years with an average duration of 14.1 +/- 9.2 Years. The prevalence of depressive disorders among epileptic patients in our survey was 18.5%. According to sex, the prevalence was 23.1% in women and 15.1% in men. The depressed patients were compared with the remaining patients without depression with regard to seizure variables and sociodemographic characteristics. The epilepsy-depression and epilepsy-control groups did not differ significantly in the duration of epilepsy or in the type of anticonvulsant therapy (mono versus polytherapy). Three variables were significantly different between the two groups. The mean age in the epilepsy-depression group was significantly higher (34.4 +/- 9.6 Years versus 29.4 +/- 10.9, p<0.03), the mean age of epilepsy age of onset was also higher in the epilepsy-depression group than in the epilepsy-control group (21.8 +/- 11.9 Years versus 15.04 +/- 11.0, p<0.03) and the seizure frequency per week was more important among depressed epileptic patients (2.4 + 5.2 seizures versus 0.4 + 1.5, p<0.007). The present survey confirms the findings of previous studies that the prevalence of the comorbidity between epilepsy and depression is common in specialised outpatient units. The detection and the treatment of depressive disorders among the epileptic patients remains a very great challenge in the management of the epileptic illness. It will improve the quality of life of these patients. A closer involvement of psychiatric and psychological treatment in patient management is necessary.

Stroke rehabilitation: application and analysis of the modified Barthel index in an Arab community.

PURPOSE: The primary aim was to provide experience with a functional evaluation instrument (modified Barthel index MBI) that assures the quality of work and identify its deficiencies, familiarize our staff with the feasibility of its application on our local inpatients and educate our personnel in the field of stroke rehabilitation. The secondary aim was to collect data that are measurable and reproducible, identify specific local factors that adversely affect outcomes and serve as a feedback system to our national organizations. METHODS: In this prospective/retrospective study we evaluated 80 hemiplegic patients with completed stroke, admitted to hospital during the year 1989 1990. They were assessed by a neurologist, physiatrist and physiotherapist on admission and discharge using the MBI. All patients received comprehensive inpatient rehabilitation. The study was interrupted at the beginning of the Gulf crisis. However, the data were revived and retrospectively studied in the year 1994-1995. RESULTS: The MBI proved to be fully acceptable and easily applicable in our community. The rehabilitation staff became rapidly familiarized with its application and the reproduction of its data. The goals of rehabilitation were achieved through the reduction in the number of individuals in the more severe MBI scores and the increase in the number of individuals in the less severe ones. Significant improvements occurred in dressing of the upper and lower body, washing, grooming, care of perineum, transfer chair, toilet and walking on a level of 50 yards (p < or = 0.0005). CONCLUSIONS: We conclude that MBI is simple, convenient, efficient, gives exact and accurate information about daily activities and ambulation and could be used in inpatient follow up sittings, in the Arab and culturally similar Middle East countries.

[Depression, suicidal ideation and schizophrenia]. / Dépression, suicidalité et schizophrénie.

UNLABELLED: The aim of this study was to find out the prevalence of depressive symptoms in patients with schizophrenia, with a special emphasis on suicidal thoughts and behaviors. 183 schizophrenic patients, according to ICD-10 criteria, were included. The interview was done by a psychiatrist using a questionnaire (socio-demographic data, premorbid functioning, schizophrenic and depressive antecedents and current depressive and suicidal thoughts and behaviors). The mean age was 34.3 +/- 8 years; 90% of the sample were males; 12.6% were married and 17% had children. RESULTS: The mean age at onset of the illness was 24 +/- 5.9 years and its mean duration was 4.8 +/- 1.3 years. The paranoid type was found in 78% of cases, and the schizo-affective one in 7.8%. During the assessment, 44.3% of the patients had depressive symptoms, 2.7% of them had suicidal ideas and 5% had a specific plan to implement them; 40% of the patients with suicidal ideas had a depression or had a painful consciousness of their illness. These results confirm the ones of other studies in the field: depression is frequent among patients with schizophrenia. An emphasis should be put on the necessity of treating both conditions when they co-exist in the same patient.

Analysis of a human cDNA containing a tissue-specific alternatively spliced LIM domain.

A unique clone, isolated from a human pancreatic cDNA library, was sequenced and characterized. Northern blot analysis showed that the gene is active in a number of fetal and adult tissues, and immunoblots showed expression in nuclear and cytosolic cell fractions. The gene corresponding to the clone was localized to chromosome 13 by human/rodent somatic cell hybrid panels. The largest open reading frame contains a LIM domain, and the deduced peptide from the open reading frame appears to have the characteristics of a LIM-only protein, designated LMO7. RT-PCR and genomic sequence analyses indicate that expression of this gene product is subject to tissue-specific modulation by elimination of the LIM domain by alternative splicing in neural tissues.

Responses of some Nigerian vegetables of plant growth regulator treatments.

The effects of single and combined growth regulator treatments of indole-3-acetic acid (IAA), gibberellic acid (GA3) and coconut milk on plant height, yield, chlorophyll and vitamin contents of Abelmoschus esculetus L and Solanum gilo L were investigated. The single growth regulator treatments consisted of 50mg/L, 100 mg/L of IAA and GA3 and 10%, 15% of coconut milk. In case of combined growth regulator treatments, the treatments were 100mg/L IAA + 100mg/L GA3, 100mg/L IAA + 15% coconut milk and 100mg/L GA3 + 15% coconut milk. Control vegetable plants were sprayed with water. Single treatments of 100mg/L IAA,100mg/L GA3. 10% and 15% coconut milk resulted in significantly increased plant height, chlorophyll contents and yield of A. esculentus, H. sabdariffa and S. gilo while only combined treatments of 100mg/L IAA + 10% coconut milk and 100mg/L GA3 + 15% coconut milk had such an effect on A. esculentus and S. gilo but not on H. sabdariffa. Moreover, singletreatments of 100mg/L GA3 and 15% coconut milk caused significantly higher vitamins A, B6 and C contents of treated plants whereas the combined treatments produced such an effect on only vitamin C contents of treated plants. Growth regulator treatments of 100mg/L GA3 and 15% coconut milk were consistently the best out of the entire growth regulator treatments tried with the treated plants having the greatest plant height, yield, chlorophyll and vitamin C contents.