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1.
Heliyon ; 10(10): e30839, 2024 May 30.
Article in English | MEDLINE | ID: mdl-38778936

ABSTRACT

Globally, the demand for natural remedies such as honey to manage ailments has increased. Yet, the health benefits and chemical composition of African honeys are not well understood. Therefore, this study aimed to characterise the bio-functional properties and the phytochemical composition of 18 Apis mellifera honeys from Kenya, Uganda, and Cameroon in comparison to the popular and commercially available Manuka 5+ honey from New Zealand. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay (DPPH-RSA) was used to determine the antioxidant property, whilst the agar well diffusion and broth dilution (Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)) assays were used to determine antimicrobial property. Further, colorimetric methods were used for phytochemical analysis. Our results showed that honeys collected from Rift Valley region of Kenya (e.g. Poi, Salabani and Mbechot) and Western region of Cameron (e.g. Bangoulap) had the highest antioxidant (DPPH RSA of 41.52-43.81%) and antimicrobial (MIC (3.125-6.25% w/v) and MBC (6.25-12.5% w/v)) activities. Additionally, the total flavonoid (770-970 mg QE/100 g), phenol (944.79-1047.53 mg GAE/100 g), terpenoid (239.78-320.89 mg LE/100 g) and alkaloid (119.40-266.57 mg CE/100 g) contents reached the highest levels in these bioactive African honeys, which significantly and positively correlated with their bio-functional properties. The functional and phytochemical composition of these bioactive African honeys were similar to or higher than those of the Manuka 5+ honey. Furthermore, gas chromatography-mass spectrometry analysis of African honeys revealed 10 most prominent volatile organic compounds that contribute to their geographical distinction: triacontane, heptacosane, (Z)-9-tricosene, tetracosane, 6-propyl-2,3-dihydropyran-2,4-dione, octacosane, 1,2,4-trimethylcyclohexane, 1,3-bis(1,1-dimethylethyl) benzene, 2-methylheptane and phytol. Overall, our findings suggest that some of the tested African honeys are natural sources of antimicrobial and antioxidant therapies that can be exploited upon further research and commercialized as high value honey.

2.
Nat Commun ; 14(1): 1389, 2023 03 13.
Article in English | MEDLINE | ID: mdl-36914628

ABSTRACT

Protected Areas (PAs) are the cornerstone of biodiversity conservation. Here, we collated distributional data for >14,000 (~70% of) species of amphibians and reptiles (herpetofauna) to perform a global assessment of the conservation effectiveness of PAs using species distribution models. Our analyses reveal that >91% of herpetofauna species are currently distributed in PAs, and that this proportion will remain unaltered under future climate change. Indeed, loss of species' distributional ranges will be lower inside PAs than outside them. Therefore, the proportion of effectively protected species is predicted to increase. However, over 7.8% of species currently occur outside PAs, and large spatial conservation gaps remain, mainly across tropical and subtropical moist broadleaf forests, and across non-high-income countries. We also predict that more than 300 amphibian and 500 reptile species may go extinct under climate change over the course of the ongoing century. Our study highlights the importance of PAs in providing herpetofauna with refuge from climate change, and suggests ways to optimize PAs to better conserve biodiversity worldwide.


Subject(s)
Climate Change , Ecosystem , Animals , Conservation of Natural Resources , Reptiles , Amphibians , Biodiversity
3.
Primates ; 62(3): 537-546, 2021 May.
Article in English | MEDLINE | ID: mdl-33759106

ABSTRACT

The growing dependence of villagers on local forests (food, wood, etc.) makes the comparative assessment of the perceptions they have of the forest and its wildlife increasingly important for setting conservation priorities. While hunting and habitat loss are important threats to primates' existence worldwide, more attention has been focused on diurnal species, while little is known about their nocturnal counterparts. Strepsirrhini is a group of nocturnal primates with galago and potto as the only representatives on mainland Africa. To assess the perception of locals and their impacts on the conservation of these primates, questionnaires were administered to 79 household heads in four villages located in community forests around Mount Cameroon National Park. Amongst the respondents, over 90% admitted that these animals are eaten in their communities. Nocturnal primates were not only hunted for food, but also used in medicine and rituals and to make drums. However, the habit of eating nocturnal primates seems to be uncommon, as most respondents had not consumed any primate bushmeat in the last 5 years. The knowledge and support of wildlife conservation manifested by the villagers did not reflect the reality on the ground, as forest clearing for agriculture takes place regularly across the villages. Our findings suggest that bushmeat is not the main threat to nocturnal primates in this area, with habitat loss potentially representing a bigger problem for their existence in the near future.


Subject(s)
Strepsirhini , Animals , Biodiversity , Cameroon , Conservation of Natural Resources , Mammals , Perception , Primates
4.
Proc Biol Sci ; 287(1930): 20200449, 2020 07 08.
Article in English | MEDLINE | ID: mdl-32635865

ABSTRACT

Predicting species' capacity to respond to climate change is an essential first step in developing effective conservation strategies. However, conservation prioritization schemes rarely take evolutionary potential into account. Ecotones provide important opportunities for diversifying selection and may thus constitute reservoirs of standing variation, increasing the capacity for future adaptation. Here, we map patterns of environmentally associated genomic and craniometric variation in the central African rodent Praomys misonnei to identify areas with the greatest turnover in genomic composition. We also project patterns of environmentally associated genomic variation under future climate change scenarios to determine where populations may be under the greatest pressure to adapt. While precipitation gradients influence both genomic and craniometric variation, vegetation structure is also an important determinant of craniometric variation. Areas of elevated environmentally associated genomic and craniometric variation overlap with zones of rapid ecological transition underlining their importance as reservoirs of evolutionary potential. We also find that populations in the Sanaga river basin, central Cameroon and coastal Gabon are likely to be under the greatest pressure from climate change. Lastly, we make specific conservation recommendations on how to protect zones of high evolutionary potential and identify areas where populations may be the most susceptible to climate change.


Subject(s)
Climate Change , Murinae , Adaptation, Physiological , Animals , Biological Evolution , Ecosystem
6.
Malar J ; 16(1): 31, 2017 01 17.
Article in English | MEDLINE | ID: mdl-28095873

ABSTRACT

BACKGROUND: Long-lasting insecticidal nets (LLINs) are effective tools at reducing malaria transmission. In Cameroon, following the first national mass distribution campaign in 2011, there has been no follow up on the efficacy of LLINs distributed. The aim of this report is to assess the physical integrity and insecticidal potency of LLINs distributed in three cities with contrasting socio economic status (SES) and to evaluate the use and care for bed nets owned by individuals. METHODS: The study was conducted in Limbe, Tiko and Buea three localities in the Fako division of the South West Region of Cameroon. Tiko had the highest SES based on the type of building materials used, followed respectively by Limbe and Buea. The use and care for bed nets was assessed using a questionnaire, the physical state of bed nets evaluated following WHOPES recommendation for determining size of holes and the residual insecticidal activity of retrieved bed nets determined through a cone bioassay using susceptible strains of mosquitoes. RESULTS: Of the 241 households visited in Limbe (n = 81), Tiko (n = 80) and Buea (n = 80), 186 (77.2%) had LLINs, with no significant variations from the selected study locations. However, bed net coverage was not meeting World Health Organization standards (p < 0.0001). Six different brands of LLINs were recorded, and the majority were those provided by the NMCP through the 2011 national mass campaign or antenatal care programme. Based on the calculation of the Proportionate Hole Index (PHI) as indicator of physical integrity of nets, the proportion of nets classified as serviceable (versus too torn) differed statistically according to locations (p value = 0.04), with 63.8% in Tiko, 50% in Limbe and 47% in Buea. Of the 20 nets tested for their efficacy against susceptible strains of mosquito, 42.6% (3 nets) were optimally effective in Tiko, 57.4% (4), 16.7% (1) and 14.3% (1) were minimally effective in Tiko, Buea and Limbe respectively. Finally; 85.7% (6) and 83.3% (5) were not effective in Limbe and Buea. CONCLUSIONS: These findings pinpoint the need for more frequent replacement of LLINs especially for people with low SES and also the need for the promotion of good practices on the maintenance and washing of nets.


Subject(s)
Culicidae/drug effects , Insecticide-Treated Bednets/statistics & numerical data , Insecticides/pharmacology , Maintenance , Mosquito Control/methods , Adult , Animals , Biological Assay , Cameroon , Cities , Cross-Sectional Studies , Culicidae/physiology , Family Characteristics , Humans , Surveys and Questionnaires
7.
Br J Dermatol ; 173(1): 93-105, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25864856

ABSTRACT

BACKGROUND: Patients with erythrodermic disease are a diagnostic challenge regarding the clinical and histological differential diagnosis. OBJECTIVES: To evaluate histopathological and immunohistochemical diagnostic markers for Sézary syndrome. METHODS: Ninety-seven erythrodermic cases [Sézary syndrome (SS), n = 57; erythrodermic inflammatory dermatoses (EIDs), n = 40] were collected by the EORTC Cutaneous Lymphoma Task Force histopathology group. Evaluation criteria were (i) epidermal and dermal changes; (ii) morphology of the infiltrate; (iii) immunohistochemical analysis of marker loss (CD2, CD3, CD4, CD5 and CD7); (iv) bystander infiltrate by staining for CD8, FOXP3 and CD25; and (v) expression of Ki-67, CD30, PD-1 and MUM-1. RESULTS: The workshop panel made a correct diagnosis of SS in 51% of cases (cutaneous T-cell lymphoma 81%) and of EID in 80% without clinical or laboratory data. Histology revealed a significantly increased degree of epidermotropism (P < 0.001) and more intraepidermal atypical lymphocytes (P = 0.0014) in SS biopsies compared with EID. Pautrier microabscesses were seen only in SS (23%) and not in EID (P = 0.0012). SS showed significantly more dermal cerebriform and blastic lymphocytes than EID. Immunohistochemistry revealed a significant loss of CD7 expression (< 50%) in 33 of 51 (65%) cases of SS compared with two of 35 (6%) EID (P < 0.001). The lymphocytic infiltrate in SS skin samples was found significantly to express PD-1 (P = 0.0053), MUM-1 (P = 0.0017) and Ki-67 (P < 0.001), and showed less infiltration of CD8(+) lymphocytes (P < 0.001). A multivariate analysis identified CD7 loss, increased numbers of small cerebriform lymphocytes, low numbers of CD8(+) lymphocytes and increased proliferation (Ki-67(+) lymphocytes) as the strongest indicators for the diagnosis of SS. CONCLUSIONS: A number of different histological and immunophenotypical criteria are required to differentiate between SS and EIDs.


Subject(s)
Biomarkers, Tumor/metabolism , Sezary Syndrome/pathology , Skin Neoplasms/pathology , Skin/pathology , Adult , Aged , Aged, 80 and over , Antigens, CD/metabolism , Biopsy/methods , Diagnosis, Differential , Female , Follow-Up Studies , Forkhead Transcription Factors/metabolism , Humans , Immunohistochemistry , Lymphocytes/pathology , Male , Middle Aged , Phenotype , Prognosis , Programmed Cell Death 1 Receptor/metabolism , Sezary Syndrome/immunology , Sezary Syndrome/mortality , Skin Neoplasms/immunology , Skin Neoplasms/mortality
10.
Cell Death Dis ; 4: e469, 2013 Jan 24.
Article in English | MEDLINE | ID: mdl-23348583

ABSTRACT

The CD20-homolog Ms4a8a has recently been shown to be a marker for alternatively activated macrophages but its expression is not restricted to hematopoietic cells. Here, MS4A8A/MS4A8B expression was detected in differentiated intestinal epithelium in mouse and human, respectively. Interestingly, no MS4A8B expression was found in human colon carcinoma. Forced overexpression of MS4A8A in the murine colon carcinoma cell line CT26 led to a reduced proliferation and migration rate. In addition, MS4A8A-expressing CT26 cells displayed an increased resistance to hydrogen peroxide-induced apoptosis, which translated in an increased end weight of subcutaneous MS4A8A+ CT26 tumors. Gene profiling of MS4A8A+ CT26 cells revealed a significant regulation of 225 genes, most of them involved in cytoskeletal organization, apoptosis, proliferation, transcriptional regulation and metabolic processes. Thereby, the highest upregulated gene was the intestinal differentiation marker cytokeratin 20. In conclusion, we show that MS4A8A/MS4A8B is a novel differentiation marker of the intestinal epithelium that supports the maintenance of a physiological barrier function in the gut by modulating the transcriptome and by conferring an increased resistance to reactive oxygen species. The absence of MS4A8B in human colonic adenocarcinomas shown in this study might be a helpful tool to differentiate between healthy and neoplastic tissue.


Subject(s)
Epithelial Cells/metabolism , Membrane Proteins/metabolism , Animals , Apoptosis/drug effects , Caco-2 Cells , Cell Line, Tumor , Cell Proliferation , Cell Transformation, Neoplastic , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Cytoskeleton , Gene Expression Profiling , Humans , Hydrogen Peroxide/toxicity , Intestinal Mucosa/pathology , Keratin-20/metabolism , Membrane Proteins/genetics , Mice , Mice, Inbred BALB C , Reactive Oxygen Species/metabolism
12.
Hautarzt ; 61(8): 700-4, 2010 Aug.
Article in German | MEDLINE | ID: mdl-20625882

ABSTRACT

Cranial fasciitis is a rare variation of nodular fasciitis that occurs in the region of the capillitium. We report on a 29-year-old patient who presented with a 2-month history of a tumor progressively increasing in size located on the occiput. Histological examination revealed a tumor, consisting of tightly packed spindle-shaped cells with underlying myxoid stroma, which extended from the dermis to the subcutis. Actin and vimentin were detected by immunohistochemistry. We established a diagnosis of cranial fasciitis and excised the tumor. Especially when a child or young adult presents with a tumor in the skull area, consideration should be given to cranial fasciitis in the differential diagnosis to avoid unnecessary and possibly very invasive treatment approaches.


Subject(s)
Fasciitis/diagnosis , Scalp Dermatoses/diagnosis , Skin Ulcer/diagnosis , Adult , Biopsy , Diagnosis, Differential , Fasciitis/pathology , Humans , Male , Middle Aged , Scalp/pathology , Scalp Dermatoses/pathology , Skin Ulcer/pathology
13.
Occup Environ Med ; 60(3): 212-6, 2003 Mar.
Article in English | MEDLINE | ID: mdl-12598670

ABSTRACT

BACKGROUND: Serious delayed neuropsychological sequelae may complicate carbon monoxide intoxication. The existence of minor manifestations, especially memory disturbances, is not well documented. AIMS: To study several memory functions after carbon monoxide intoxication. METHODS: In a prospective study, 32 poisoned patients without risk factors for cognitive disturbances were compared to 32 paired control subjects one month after acute carbon monoxide intoxication (blood carbon monoxide concentration at least 1.0 mmol/l), who had been treated with standard conventional therapy. Psychometric tests included Buschke's verbal memory testing, verbal digit span, Corsi's visuospatial span, reaction times, Stroop's colours decoding test, and verbal fluency test. RESULTS: (1) Memory functions in poisoned subjects were not worse than in the control group and were even better in some areas: learning, word recall, and quality of learning by Buschke's verbal memory testing. Attention was also better in the patients, in whom visual reaction time was shorter than in controls. (2) Results of several memory functions-quality of learning and immediate visual memory-were positively correlated with the initial carbon monoxide level. CONCLUSIONS: In a highly selected subset of patients devoid of risk factors for memory impairment, memory, objectively evaluated by psychometric testing, was not worse one month after carbon monoxide intoxication in patients undergoing standard treatment than in paired control subjects.


Subject(s)
Air Pollutants/adverse effects , Carbon Monoxide Poisoning/psychology , Environmental Exposure , Memory Disorders/chemically induced , Acute Disease , Adult , Case-Control Studies , Female , Humans , Learning Disabilities/chemically induced , Male , Middle Aged , Neuropsychological Tests , Prospective Studies , Time Factors
14.
Int Arch Occup Environ Health ; 74(4): 285-8, 2001 May.
Article in English | MEDLINE | ID: mdl-11401021

ABSTRACT

OBJECTIVES: Long-term exposure to toluene may result in subtle impairment of cognitive functions. However, it is not clear whether this impairment is due to the presence of the solvent in the body or if it persists after its elimination from blood. The aim of this study is to compare cognitive functions between toluene-exposed workers (at least 48 h after removal from exposure) and non-exposed workers. METHODS: Seventy-two workers exposed for at least 5 years to toluene (9 to 467 ppm) completed a questionnaire and psychometric tests. The results were compared with those of 61 non-exposed workers. An alveolar air sample was taken just before the tests to ensure the absence of toluene. RESULTS: Results of the vocabulary test were slightly better in exposed (correct words: 21 +/- 0.6) than in non-exposed workers (19 +/- 0.8) (P < 0.05). No differences were found for simple reaction time, digit symbol, digit span, continuous tracking test, color word and switching attention test. CONCLUSIONS: The results of this study do not support the notion of the persistence of cognitive effects of toluene after elimination of the solvent from blood.


Subject(s)
Cognition/drug effects , Solvents/adverse effects , Toluene/adverse effects , Data Interpretation, Statistical , Female , Humans , Male , Middle Aged , Neurobehavioral Manifestations , Occupational Exposure , Psychometrics , Surveys and Questionnaires , Time Factors , Toluene/blood
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