Comparison of extraction methods in vitro Plasmodium falciparum: A 1H NMR and LC-MS joined approach

Malaria is a parasitic disease that remains a global concern and the subject of many studies. Metabolomics has emerged as an approach to better comprehend complex pathogens and discover possible drug targets, thus giving new insights that can aid in the development of antimalarial therapies. However, there is no standardized method to extract metabolites from in vitro Plasmodium falciparum intraerythrocytic parasites, the stage that causes malaria. Additionally, most methods are developed with either LC-MS or NMR analysis in mind, and have rarely been evaluated with both tools. In this work, three extraction methods frequently found in the literature were reproduced and samples were analyzed through both LC-MS and 1H NMR, and evaluated in order to reveal which is the most repeatable and consistent through an array of different tools, including chemometrics, peak detection and annotation. The most reliable method in this study proved to be a double extraction with methanol and methanol/water (80:20, v/v). Metabolomic studies in the field should move towards standardization of methodologies and the use of both LC-MS and 1H NMR in order to make data more comparable between studies and facilitate the achievement of biologically interpretable information.

First comprehensive untargeted metabolomics study of suramin-treated Trypanosoma brucei: an integrated data analysis workflow from multifactor data modelling to functional analysis

INTRODUCTION

Human African trypanosomiasis, commonly known as sleeping sickness, is a vector-borne parasitic disease prevalent in sub-Saharan Africa and transmitted by the tsetse fly. Suramin, a medication with a long history of clinical use, has demonstrated varied modes of action against Trypanosoma brucei. This study employs a comprehensive workflow to investigate the metabolic effects of suramin on T. brucei, utilizing a multimodal metabolomics approach.

OBJECTIVES

The primary aim of this study is to comprehensively analyze the metabolic impact of suramin on T. brucei using a combined liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance spectroscopy (NMR) approach. Statistical analyses, encompassing multivariate analysis and pathway enrichment analysis, are applied to elucidate significant variations and metabolic changes resulting from suramin treatment.

METHODS

A detailed methodology involving the integration of high-resolution data from LC-MS and NMR techniques is presented. The study conducts a thorough analysis of metabolite profiles in both suramin-treated and control T. brucei brucei samples. Statistical techniques, including ANOVA-simultaneous component analysis (ASCA), principal component analysis (PCA), ANOVA 2 analysis, and bootstrap tests, are employed to discern the effects of suramin treatment on the metabolomics outcomes.

RESULTS

Our investigation reveals substantial differences in metabolic profiles between the control and suramin-treated groups. ASCA and PCA analysis confirm distinct separation between these groups in both MS-negative and NMR analyses. Furthermore, ANOVA 2 analysis and bootstrap tests confirmed the significance of treatment, time, and interaction effects on the metabolomics outcomes. Functional analysis of the data from LC-MS highlighted the impact of treatment on amino-acid, and amino-sugar and nucleotide-sugar metabolism, while time effects were observed on carbon intermediary metabolism (notably glycolysis and di- and tricarboxylic acids of the succinate production pathway and tricarboxylic acid (TCA) cycle).

CONCLUSION

Through the integration of LC-MS and NMR techniques coupled with advanced statistical analyses, this study identifies distinctive metabolic signatures and pathways associated with suramin treatment in T. brucei. These findings contribute to a deeper understanding of the pharmacological impact of suramin and have the potential to inform the development of more efficacious therapeutic strategies against African trypanosomiasis.

Trypanosoma brucei: Metabolomics for analysis of cellular metabolism and drug discovery

BACKGROUND

Trypanosoma brucei is the causative agent of Human African Trypanosomiasis (also known as sleeping sickness), a disease causing serious neurological disorders and fatal if left untreated. Due to its lethal pathogenicity, a variety of treatments have been developed over the years, but which have some important limitations such as acute toxicity and parasite resistance. Metabolomics is an innovative tool used to better understand the parasite's cellular metabolism, and identify new potential targets, modes of action and resistance mechanisms. The metabolomic approach is mainly associated with robust analytical techniques, such as NMR and Mass Spectrometry. Applying these tools to the trypanosome parasite is, thus, useful for providing new insights into the sleeping sickness pathology and guidance towards innovative treatments.

AIM OF REVIEW

The present review aims to comprehensively describe the T. brucei biology and identify targets for new or commercialized antitrypanosomal drugs. Recent metabolomic applications to provide a deeper knowledge about the mechanisms of action of drugs or potential drugs against T. brucei are highlighted. Additionally, the advantages of metabolomics, alone or combined with other methods, are discussed.

KEY SCIENTIFIC CONCEPTS OF REVIEW

Compared to other parasites, only few studies employing metabolomics have to date been reported on Trypanosoma brucei. Published metabolic studies, treatments and modes of action are discussed. The main interest is to evaluate the metabolomics contribution to the understanding of T. brucei's metabolism.

A Validated HPLC-PDA-HRMS Method to Investigate the Biological Stability and Metabolism of Antiparasitic Triterpenic Esters

Pentacyclic triterpenes (PTs) are commonly found in medicinal plants with well-known antiparasitic effects. Previous research on C-3 and C-27 triterpenic esters showed effective and selective in vitro antiparasitic activities and in vivo effectiveness by parenteral routes. The aim of this study was to determine triterpenic esters' stability in different biological-like media and the main microsomal degradation products. An HPLC-PDA method was developed and validated to simultaneously analyze and quantify bioactive triterpenic esters in methanol (LOQ: 2.5 and 1.25-100 µg/mL) and plasma (LOQ: 5-125 µg/mL). Overall, both triterpenic esters showed a stable profile in aqueous and buffered solutions as well as in entire plasma, suggesting gaining access to the ester function is difficult for plasma enzymes. Conversely, after 1 h, 30% esters degradation in acidic media was observed with potential different hydrolysis mechanisms. C-3 (15 and 150 µM) and C-27 esters (150 µM) showed a relatively low hepatic microsomal metabolism (<23%) after 1 h, which was significantly higher in the lowest concentration of C-27 esters (15 µM) (>40% degradation). Metabolic HPLC-PDA-HRMS studies suggested hydrolysis, hydroxylation, dehydration, O-methylation, hydroxylation and/or the reduction of hydrolyzed derivatives, depending on the concentration and the position of the ester link. Further permeability and absorption studies are required to better define triterpenic esters pharmacokinetic and specific formulations designed to increase their oral bioavailability.

Effect of fasting and feeding on apolipoprotein A-I kinetics in preβ1-HDL, α-HDL, and triglyceride-rich lipoproteins

The aim of this study was to compare the kinetics of apolipoprotein (apo)A-I during fed and fasted states in humans, and to determine to what extent the intestine contributes to apoA-I production. A stable isotope study was conducted to determine the kinetics of apoA-I in preβ₁ high-density lipoprotein (HDL) and α-HDL. Six healthy male subjects received a constant intravenous infusion of ²H₃-leucine for 14 h. Subjects in the fed group also received small hourly meals. Blood samples were collected hourly during tracer infusion and then daily for 4 days. Tracer enrichments were measured by mass spectrometry and then fitted to a compartmental model using asymptotic plateau of very-low-density lipoprotein (VLDL) apoB100 and triglyceride-rich lipoprotein (TRL) apoB48 as estimates of hepatic and intestinal precursor pools, respectively. The clearance rate of preβ₁-HDL-apoA-I was lower in fed individuals compared with fasted subjects (p < 0.05). No other differences in apoA-I production or clearance rates were observed between the groups. No significant correlation was observed between plasma apoC-III concentrations and apoA-I kinetic data. In contrast, HDL-apoC-III was inversely correlated with the conversion of α-HDL to preβ₁-HDL. Total apoA-I synthesis was not significantly increased in fed subjects. Hepatic production was not significantly different between the fed group (17.17 ± 2.75 mg/kg/day) and the fasted group (18.67 ± 1.69 mg/kg/day). Increase in intestinal apoA-I secretion in fed subjects was 2.20 ± 0.61 mg/kg/day. The HDL-apoA-I kinetics were similar in the fasted and fed groups, with 13% of the total apoA-I originating from the intestine with feeding.

Validation according to European and American regulatory agencies guidelines of an LC-MS/MS method for the quantification of free and total ropivacaine in human plasma

Background

Ropivacaine is a widely used local anaesthetic drug, highly bound to plasma proteins with a free plasma fraction of about 5%. Therefore, the monitoring of free drug concentration is most relevant to perform pharmacokinetic studies and to understand the drug pharmacokinetic/pharmacodynamic (PK/PD) relationship.

Methods

A high-sensitivity liquid chromatography-tandem mass spectrometry (LC-MS/MS) method using reverse-phase LC and electrospray ionisation mass spectrometry with multiple reaction monitoring (MRM) is described for the quantitation of both free and total ropivacaine in human plasma. Ropivacaine-d7 was used as an internal standard (IS).

Results

The method was validated in the range 0.5–3000 ng/mL, with five levels of QC samples and according to the European Medicine Agency and Food and Drug Administration guidelines. The performance of the method was excellent with a precision in the range 6.2%–14.7%, an accuracy between 93.6% and 113.7% and a coefficient of variation (CV) of the IS-normalised matrix factor below 15%. This suitability of the method for the quantification of free and total ropivacaine in clinical samples was demonstrated with the analysis of samples from patients undergoing knee arthroplasty and receiving a local ropivacaine infiltration.

Conclusions

A method was developed and validated for the quantification of free and total ropivacaine in human plasma and was shown suitable for the analysis of clinical samples.

Metabolic reprograming of LPS-stimulated human lung macrophages involves tryptophan metabolism and the aspartate-arginosuccinate shunt

Lung macrophages (LM) are in the first line of defense against inhaled pathogens and can undergo phenotypic polarization to the proinflammatory M1 after stimulation with Toll-like receptor agonists. The objective of the present work was to characterize the metabolic alterations occurring during the experimental M1 LM polarization. Human LM were obtained from resected lungs and cultured for 24 hrs in medium alone or with 10 ng.mL-1 lipopolysaccharide. Cells and culture supernatants were subjected to extraction for metabolomic analysis with high-resolution LC-MS (HILIC and reverse phase -RP- chromatography in both negative and positive ionization modes) and GC-MS. The data were analyzed with R and the Worklow4Metabolomics and MetaboAnalyst online infrastructures. A total of 8,741 and 4,356 features were detected in the intracellular and extracellular content, respectively, after the filtering steps. Pathway analysis showed involvement of arachidonic acid metabolism, tryptophan metabolism and Krebs cycle in the response of LM to LPS, which was confirmed by the specific quantitation of selected compounds. This refined analysis highlighted a regulation of the kynurenin pathway as well as the serotonin biosynthesis pathway, and an involvement of aspartate-arginosuccinate shunt in the malate production. Macrophages M1 polarization is accompanied by changes in the cell metabolome, with the differential expression of metabolites involved in the promotion and regulation of inflammation and antimicrobial activity. The analysis of this macrophage immunometabolome may be of interest for the understanding of the pathophysiology of lung inflammatory disesases.

A split-range acquisition method for the non-targeted metabolomic profiling of human plasma with hydrophilic interaction chromatography - high-resolution mass spectrometry

Untargeted metabolomics of human plasma with mass spectrometry is of particular interest in medical research to explore pathophysiology, find disease biomarkers or for the understanding of the response to pharmacotherapy. Since analytical performances may be impacted by the laboratory environment and the acquisition method settings, the objectives of this study were to assess the role of interfering compounds and to propose an acquisition method to maximize the metabolome coverage for human plasma metabolomic analysis. Human plasma samples were processed with liquid/liquid extraction then analysed with HILIC-high resolution mass spectrometry. A method with a single m/z range was compared to four methods with different split acquisition ranges and four sets of ionization source parameters were compared. The data were analysed with the R software and on the Worklow4Metabolomics online platform. The major interfering compounds were identified in blank samples where they accounted for up to 86% of the signal intensity. Splitting the acquisition range into 3 m/z ranges improved the number of detected features, the number of features with proposed annotation in the Human Metabolome Database, as well as signal intensity throughout the whole m/z range. The method performing best was the one using three m/z ranges of approximatively the same extent. Ionization source parameters also strongly affected the number of detected features. Splitting the acquisition range into 3 m/z ranges with optimized ionization source parameters allows a comprehensive analysis of the human plasma metabolome with perspectives for applications to pathophysiological studies.

Correlation between olfactory function, trigeminal sensitivity, and nasal anatomy in healthy subjects

PURPOSE

Few studies have investigated the correlation between chemosensory function (trigeminal and olfactory) and nasal volume in humans, even though nasal anatomy is crucial for the sense of smell. Aim of this study was to evaluate these correlations in normosmic subjects.

METHODS

Two hundred and fifty-six healthy volunteers (age range 19-69 years) participated. Olfactory function was investigated for (the rose-like) phenylethyl alcohol odor threshold and odor identification (OI) using the Sniffin' Sticks test, while nasal structure was evaluated by acoustic rhinometry (AR); trigeminal sensitivity was assessed in terms of detection "thresholds" for the odorless carbon dioxide (CO₂).

RESULTS

There were negative correlations between olfactory sensitivity at threshold level and minimum cross-sectional area (MCSA) in both nostrils. No significant correlations were found between OI and nasal anatomy. Similar to olfactory sensitivity, with regard to the trigeminal stimulus CO₂ for the right nostril subjects were the more sensitive the smaller the MCSA.

CONCLUSIONS

The current results emphasize the significance of nasal anatomy for trigeminal/olfactory threshold perception. Interestingly, correlations were not found between suprathreshold odor identification and nasal anatomy. Other than odor identification, odor thresholds appear to depend on subtle differences in nasal anatomy.

Plasma lipidomic analysis reveals strong similarities between lipid fingerprints in human, hamster and mouse compared to other animal species

Cardiovascular diseases are often associated with impaired lipid metabolism. Animal models are useful for deciphering the physiological mechanisms underlying these pathologies. However, lipid metabolism is contrasted between species limiting the transposition of findings from animals to human. Hence, we aimed to compare extended lipid profiles of several animal species to bring new insights in animal model selections. Human lipid phenotype was compared with those of 10 animal species. Standard plasma lipids and lipoprotein profiles were obtained by usual methods and lipidomic analysis was conducted by liquid chromatography-high-resolution mass spectrometry (LC-HRMS). As anticipated, we found contrasted lipid profiles between species. Some of them exhibited similar plasma lipids to human (non-human primate, rat, hamster, pig), but only usual lipid profiles of pigs were superimposable with human. LC-HRMS analyses allowed the identification of 106 other molecular species of lipids, common to all samples and belonging to major lipid families. Multivariate analyses clearly showed that hamster and, in a lower extent mouse, exhibited close lipid fingerprints to that of human. Besides, several lipid candidates that were previously reported to study cardiovascular diseases ranged similarly in human and hamster. Hence, hamster appeared to be the best option to study physiological disturbances related to cardiovascular diseases.

Stable Isotope Kinetic Study of ApoM (Apolipoprotein M)

OBJECTIVE

ApoM (apolipoprotein M) binds primarily to high-density lipoprotein before to be exchanged with apoB (apolipoprotein B)-containing lipoproteins. Low-density lipoprotein (LDL) receptor-mediated clearance of apoB-containing particles could influence plasma apoM kinetics and decrease its antiatherogenic properties. In humans, we aimed to describe the interaction of apoM kinetics with other components of lipid metabolism to better define its potential benefit on atherosclerosis.

APPROACH AND RESULTS

Fourteen male subjects received a primed infusion of ²H₃-leucine for 14 hours, and analyses were performed by liquid chromatography-tandem mass spectrometry from the hourly plasma samples. Fractional catabolic rates and production rates within lipoproteins were calculated using compartmental models. ApoM was found not only in high-density lipoprotein (59%) and LDL (4%) but also in a non-lipoprotein-related compartment (37%). The apoM distribution was heterogeneous within LDL and non-lipoprotein-related compartments according to plasma triglycerides (r=0.86; P<0.001). The relationships between sphingosine-1-phosphate and apoM were confirmed in all compartments (r range, 0.55-0.89; P<0.05). ApoM fractional catabolic rates and production rates were 0.16±0.07 pool/d and 0.14±0.06 mg/kg per day in high-density lipoprotein and 0.56±0.10 pool/d and 0.03±0.01 mg/kg per day in LDL, respectively. Fractional catabolic rates of LDL-apoM and LDL-apoB100 were correlated (r=0.55; P=0.042). Significant correlations were found between triglycerides and production rates of LDL-apoM (r=0.73; P<0.004).

CONCLUSIONS

In humans, LDL kinetics play a key role in apoM turnover. Plasma triglycerides act on both apoM and sphingosine-1-phosphate distributions between lipoproteins. These results confirmed that apoM could be bound to high-density lipoprotein after secretion and then quickly exchanged with a non-lipoprotein-related compartment and to LDL to be slowly catabolized.

Multiplexed peptide analysis for kinetic measurements of major human apolipoproteins by LC/MS/MS

A multiplexed assay was developed by MS to analyze, in a single run, six major human Apos involved in lipoprotein metabolism: ApoA-I, ApoA-II, ApoB100, ApoC-II, ApoC-III, and ApoE. This method was validated in vivo in six subjects who received a 14 h constant infusion of [5,5,5-(2)H3]L-leucine at 10 μM/kg/h. Plasma lipoprotein fractions were isolated from collected blood samples and were digested with trypsin. Proteotypic peptides were subsequently analyzed by LC/MS/MS. Enrichment measurement data were compared with those obtained by the standard method using GC/MS. The required time to obtain the LC/MS/MS data was less than that needed for GC/MS. The enrichments from both methods were correlated for ApoA-I (r = 0.994; P < 0.0001) and ApoB100 (r = 0.999; P < 0.0001), and the Bland-Altman plot confirmed the similarity of the two methods. Intra- and inter-assay variability calculated for the six Apos of interest did not exceed 10.7 and 12.5%, respectively, and kinetic parameters were similar and/or in agreement with previously reported data. Therefore, LC/MS/MS can be considered as a useful tool for human Apo kinetic studies using stable isotopes.

[Assistance and Support Units for the elderly: A tool for promoting health in seniors: Example of the CAAPA unit of "Sicap Rue 10", in Dakar]

As a body for reflection, dialogue and integration, the CAAPA Assistance and Support Unit of "Sicap Rue 10" allows the elderly to fully participate in the life of their society while being in good health. The unit has been set up by the local authorities following recommendations from interdepartmental cabinet meeting on 13 November, 200. Nine years after the creation of the unit, it becomes important to evaluate the degree of community participation of the elderly within that unit. This is a qualitative, descriptive and analytic study that took place from 9 October to 23 October, 2010. The two methods used to collect the data are interviewing and focus group. Using Bichmann's scale, which has been modified and adapted, the results have shown an "average-level" participation of the elderly in the creation of the CAAPA unit, its implementation as well as the follow-up and the evaluation of its activities; this participation being "open" in the composition of the piloting committee and "restricted" in mobilizing and managing material and financial resources. Recommendations have been stated for the CAAPA unit to fully play its role.

[Adult-onset Still's disease: case report in Dakar, Senegal]

Adult-onset Still's disease is a uncommon form of inflammatory rheumatism. It has rarely been reported in black Africa. The purpose of this report is to describe a case in a 49-year-old woman from Dakar, Senegal.

[Dermatomyositis and polymyositis: 21 cases in Senegal]

Dermatopolymyositis (DPM) is a term describing a group of disorders comprising multiple distinct entities depending on interactions between genetic and environmental factor. There is a paucity of studies on DPM in black Africa. The purpose of this report is to describe epidemiological, clinical, laboratory and therapeutic aspects of dermatomyositis (DM) and polymyositis (PM) observed at the Principal Hospital in Dakar, Senegal. A retrospective review as conducted of patients hospitalized for DM and PM in Medical Departments of Principal Hospital. Diagnosis of DRM was based on the criteria of Bohan and Peter's in all cases. A series of 21 black African patients was compiled including 15 with DM and 6 with PM. Mean age was 52 years and the M/F sex ratio was 0.6. The mean delay for diagnosis was 6 weeks (range, 3 to 12 weeks). Initial signs were dermatological in 12 patients, pulmonary in one and muscular in the remaining cases. The most common dermatological sign was erythema characterized by a zebra-like aspect on the extended limbs. Erythema was frequently pruriginous with a flagellate aspect on the back. Muscular signs were observed in 18 patients and included pharyngeal manifestations in 10 patients. Amyopathic DM was not observed. Cardiac abnormalities included tachycardia (4 cases), AVB (1), ischemic lesion (1), relaxation disturbances (4), pericardial effusion (3), myocarditis (2) and pulmonary hypertension (1). The most common pulmonary manifestation was interstitial lung disease observed in 6 patients. Gastrointestinal signs were noted in 9 patients including endoscopic evidence of superficial erosion in 4 cases. Electromyography (EMG) tracings revealed myogenic disease in 14 cases including 2 associated with reduced peripheral nervous conduction speed. Severe lymphopenia was observed in 3 patients but HIV serology was negative in all cases. Paraneoplasic DM was observed in 3 cases. Death occurred in 5 cases due to the cancer-related, pulmonary and infectious complications. Based on the findings of this study, the three main features of DM and PM in Senegal are flagellated and often pruriginous erythema, cardiac and interstitial lung disease, and peripheral neural involvement.

[Diabetes mellitus in sub-Saharan Africa: epidemiological aspects and management issues]

In contradiction with long-standing conventional wisdom that it is a rich country's disease, diabetes mellitus is increasingly a major concern in developing countries, especially in sub-Saharan Africa. Care facilities have not kept pace with the sharp increase in diabetes mellitus. The WHO has predicted a worldwide rise in the prevalence of diabetes that is expected to affect 300 million people by 2025. This progression is more flagrant in developing countries particularly in sub-Saharan Africa. In these countries, the expansion of diabetes is part of a broader epidemiological transition from transmissible diseases to non-transmissible diseases. A number of factors are causing this transition including aging of the population, sedentary lifestyle, and obesity. Aside from obesity, arterial hypertension is the main cardiovascular risk factor associated with diabetes. Alone or in association with other risk factors, diabetes mellitus accounts for high morbidity especially due to cardiovascular and kidney complications. Management in sub-Saharan Africa faces a number of issues: poor understanding of the extent of the problem, high cost of medications, socio-economic setting that is poorly suited to maintaining a proper diabetic diet, and limitations in infrastructure and personnel. The rapid increase in the prevalence of diabetes mellitus in sub-Saharan Africa is a serious challenge. There is an urgent need to obtain accurate figures about the extent of the pandemia as a basis for training an adequate number of health care personnel and implementing sufficient resources to allow local management. Meeting this challenge will require enhancement of the awareness and participation of all players involved in public health.

The cosmetic use of skin-lightening products during pregnancy in Dakar, Senegal: a common and potentially hazardous practice

Many women of childbearing age from sub-Saharan Africa use topical skin lighteners, some of which present a risk of toxic systemic effects. The goals of this study were to evaluate, in this environment, the frequency of this practice during pregnancy, as well as eventual consequences on pregnancy. Ninety-nine women from 6 to 9 months pregnant were randomly selected among those attending a standard maternal centre in Dakar for a prenatal visit. Investigations consisted of questions about the use of skin lighteners, a standard clinical examination, follow-up until delivery and a morning blood sample for plasma cortisol levels. Sixty-eight of the 99 selected women used skin lighteners during their current pregnancy, the main active ingredients being hydroquinone and highly potent steroids (used by 64 and 28 women, respectively). No difference in the main outcomes of pregnancy were found between skin-lightener users and the others; however, women using highly potent steroids, when compared with those who did not, had a statistically significant lower plasma cortisol level and a smaller placenta, and presented a higher rate of low-birth-weight infants. Skin lightening is a common practice during pregnancy in Dakar, and the use of steroids may result in consequences in the mother and her child.

[Leg ulcer due to hydroxyurea. A case report]

Hydroxyurea is an antineoplasic agent usually used in myeloproliferative syndromes, but also in other benign pathological circumstances. Several dermatological manifestations have been recognized as being secondary to its prolonged use, of which the leg ulcer. We report an observation. Mrs. L.D, 47 years, were hospitalized on July 14, 2004 for an ulcer of left ankle in a feverish context. She was followed since 2001 for a chronic myelogenous leukaemia, and took hydroxyurea at a rate of 1500 mg per day, with a good clinical and hematologic answer. She presented a painful ulcer compared to the left external malleolus, with purulent bottom, without signs of vascular attack. The hemogram showed a hyperleucocytosis with 24.000 white elements/mm3 with neutrophilic polynucleosis. Pus sample on the ulcer showed Pseudomonas aeruginosa, and the blood culture was negative. The cure was obtained two months after stopping hydroxyurea. The ulcer of leg related to hydroxyurea is a seldom described pathology. Its occurrence imposes the final stop of the treatment.

[Sciatic nerve in gluteal portion: application of sciatic nerve post injection lesion]

In our regions malaria is endemic and intraguteal injection is a common procedure. One unfortunate complication of that procedure appeared to be a sciatic nerve injury. The purpose of our study was to set up the anatomical feature and basis of this post injection lesion. We performed sciatic nerve gluteal dissection on 10 adults black African fresh cadavers on both side. The pathway of the nerve was 19 times in the subpiriformis canal. Only in one cadaver, the outlet of the nerve was above the piriformis muscle. In each case the pathway is identical with an oblique and vertical portion running down through the ischio-trochanteric channel. The nerve was crossed between its two portions by an arteriole coming from the inferior gluteal artery. The cutaneous projection of the sciatic nerve is distant from the upper lateral quadrant of the buttock. Intra-gluteal injections in this area doesn't damage the nerve. The anatomical variations of this nerve pathway are almost nonexistent. So, other hypothesis of sciatic nerve post injection lesion should be considered. We think that the local toxicity of quinine and its diffusion in the neurovascular gluteal area might explain the nerve lesion. Thus, the intramuscular injections should be replaced by the intravenous or rectal administration in children.

[T-cell lymphoma-leukemia caused by HTLV-1 in adults: two lymphomatous forms]

The adult T-cells lymphoma-leukemia is a serious complication by the HTLV-1 infection. It is a rarely described diseases in Africa, in spite of the frequency of the infection by this virus. We report two clinical observations of lymphomatous forms. The first observation concerned a 43 year old Senegalese woman, admitted for a deep alteration of her general status and peripheral polyadenopathies. The adenopathy biopsy set up the diagnosis of pleiomorph T lymphoma with great and medium cells. The HTLV-1 serology was positive. She had benefited of six polychemotherapy cures (cyclophosphamide, farmarubicine, oncovin, prednisone) within which she died in a cachectic presentation. The second observation concerned a 44 year old Senegalese man, admitted for peripheral polyadenopathies, ulcerated lesions of sole of the foot, and deep alteration of the general status. He presented a moderate hypercalcemia by 117 mg/l. The histological examination of a ganglionar biopsy concluded to a diffuse T lymphoma with great cells. The HTLV-1 serology was positive. The cutaneous lesions were due to a phaeohyphomycosis of Exophiala jeanselmei. The symptomatic therapeutic measures had been applied and he died within four weeks in a septicemic clinical manifestation. The adult T-cells lymphoma leukemia due to the HTLV-1 ought to be researched before any lymphomatous and leucemic manifestation by T-cells through a serological research. The prognostic stays very bad.

[The new poor expatriates in the third world]

This report describes four cases involving French expatriates who developed serious health problems while living destitute in Senegal. A 37-year-old man presented with embolism-like symptoms in relation with lung involvement due to spreading of untreated staphylococcal skin infection. A 64-year-old man was admitted for high output cardiac failure secondary to severe anemia caused by malnutrition. A 50-year-old man presented recurrent fever with loss of consciousness after successful treatment of neuromalaria and finally attributed to delirium tremens. A 25-year-old man was hospitalized with presumed meningoencephalitis that had been ongoing for two weeks. All four patients had been in Senegal for several months and had cut all ties to mainland France. Being jobless and homeless, they had been unable to obtain proper nutrition or medications. With minimal entry requirements and low-cost air travel, Senegal has been come a common sight-seeing destination and has developed a small but apparently growing population of destitute travelers. Alienation from the home community and resulting seclusion enhance clinical consequences and delay intervention by foreign service officials.

Ordinary and opportunistic enteropathogens associated with diarrhea in Senegalese adults in relation to human immunodeficiency virus serostatus

OBJECTIVES

A survey was conducted in Dakar, Senegal, to identify major types and prevalences of bacteria, parasites, fungi, and Rotaviruses associated with diarrhea in relation to human immunodeficiency virus (HIV) serostatus with the goal to provide guidance to physicians for case management.

METHODS

Etiologic agents were identified in a case control study: cases were HIV-infected patients with diarrhea (HIV+ D+) and HIV seronegative patients with diarrhea (HIV D+); controls were HIV-infected patients without diarrhea (HIV+ D ) and seronegative controls without diarrhea (HID D ). Ordinary enteric pathogens were identified by conventional methods. Different Escherichia coli pathotypes were characterized by polymerase chain reaction (PCR), identification of HEp-2 cell adherence pattern, Sereny test, GM1-ELISA, and the suckling mouse assay. Opportunistic parasites, such as Cryptosporidium and Microsporidium, were identified by the Kinyoun method and trichromic stain of Weber, respectively. Rotaviruses were identified with a commercial latex agglutination kit. Antimicrobial susceptibility testing was carried out by the disk diffusion method.

RESULTS

Among the 594 patients examined, 158 were HIV+ D+, 121 were HIV2 D+, 160 were HIV+ D , and 155 were HIV D . The main etiologies of diarrhea were different according to HIV serostatus of patients. In immunocompetent adults the main causes of diarrhea were Shigella sp (12.4%), Entamoeba histolytica(10.7%), Salmonella enterica (6.6%), and Giardia (4.9%). In the immunocompromised host the more frequent pathogens were enteroaggregative E. coli (19.6%), Microsporidium (9.4%), Cryptosporidium sp (8.2%), Rotavirus (8.2%), Shigella sp (7.6%), Candida albicans (7.6%), E. histolytica (5.1%), S. enterica (4.4%), and Isospora belli (4.4%). Also, Blastocystis hominis has to be considered as an opportunistic parasite, because it was identified only in HIV-infected patients, with higher prevalence in adults with diarrhea (2.5% in HIV+ D+ patients; 0.6% in HIV+ D patients). High level of asymptomatic carriage of Ascaris lumbricoides and Trichuris trichiura and some cases of multiple infections were observed. Fungi, Cryptosporidium sp and Microsporidium sp, were often identified in patients with low CD4 counts (range, 79 250 cells/mL). Independently from HIV-serostatus, CD4 count was lower in diarrheic persons, suggesting that diarrhea is a debilitating illness and that effective management of diarrhea can prevent immunosuppression. Isolated enteropathogenic strains displayed high resistance to most antibiotics used in Senegal for treating diarrhea (ampicillin, tetracycline, cotrimoxazole); they were susceptible to amikacin, gentamicin, and norfloxacin.

CONCLUSION

These epidemiologic data suggest that guidelines for the management of diarrhea during HIV infection in Dakar should be updated.

[First case of cutaneous plasmocytoma in Africa]

Cutaneous plasmacytoma are dermo-hypodermic plasmacytic infiltrations. Occurrence is quite rare. Primary plasmacytoma and metastatic plasmacytoma in myeloma are distinguished. Firm, asymptomatic unique or multiple nodules are the common clinical form. We report the first african case of cutaneous plasmacytoma occurring in an IgG myeloma. It was a 73 year-old man with history of IgG myeloma, stade III of Durie and Salmon classification. At his third chemotherapy, he presented a pre-stemal nodule growing since 15 days. Histologic examination confirmed the diagnosis of cutaneous plasmacytoma. One months later news nodules and cranial lacunas were observed. It is important for the clinician to well known this complication of myeloma because of its bad prognosis. Moreover it should make modify the therapeutic protocol, if it's possible.

[Infective etiology of diarrhea in adults with HIV infection in Dakar: a case-control study on 594 patients]

A survey was conducted in Dakar, Senegal from May 1997 to May 1999, to identify major types and prevalences of bacteria, parasites, fungi and Rotaviruses associated with diarrhea in relation to human immunodeficiency virus serostatus with the aim to provide guidance to physicians for case management. Etiologic agents were identified in a case-control study: cases were HIV-infected patients with diarrhea (HIV+ D+) and HIV seronegative patients with diarrhea (HIV- D+); controls were HIV-infected patients without diarrhea (HIV+ D-) and seronegative controls without diarrhea (HIV- D-). Strict enteric pathogens were identified by conventional methods. Different E. coli pathotypes were characterized by PCR. Opportunistic parasites such as Cryptosporidium and Microsporidium were identified by the Kinyoun method and trichromic stain of Weber respectively. Rotaviruses were identified with a commercial latex agglutination kit. Antimicrobial susceptibility testing was carried out by the disk diffusion method. A total of 594 patients were examined (158 HIV+D+, 121 HIV- D+, 160 HIV+ D- and 155 HIV- D-). In immunocompetent adults the main causes of diarrhea were: Shigella sp. (12.4%), Entamoeba histolytica (10.7%), Salmonella enterica (6,6%) and Giardia lamblia (4.9%). In the immunocompromised host the more frequent pathogens were: enteroaggregative E.coli (19,6%), Microsporidium(9.4%), Cryptosporidium sp.(8.2%), Rotavirus (8.2%), Shigella sp. (7.6%), Candida albicans (7.6%), Entamoeba histolytica (5,1%), Salmonella enterica (4.4%), Isospora belli (4.4%) and Blastocystis hominis (2,5%). Isolated enteropathogenic strains displayed high resistance to most antibiotics used in Senegal for treating diarrhea (tetracycline, cotrimoxazole); they were susceptible to quinolons and cephalosporins III .

[Taurodontism and the pyramidal tooth at the level of the molar. Prevalence in the Senegalese population 15 to 19 years of age]

This study was done to establish the prevalence of taurodontism and pyramidal molars in Senegalese people using the criteria of SCHIFFFMAN and CHANANNEL for taurodontism and the criteria of BRABANT for pyramidal molar, the first and second molars on the panoramic radiograph of 150 consecutive 15-19 year-old Senegalese people were assessed. Results have shown that taurodontism and pyramidal molars were present in 48.6% of patients (20% of teeth). Taurodontism was present in 48% (18.8% of teeth) of patients whereas prevalence of pyramidal molar was 4.6% (1.6% of teeth). Taurodontism was alone in 91.6% of case while pyramidal molar was alone in 8.6% of case.

[Prevalence of taurodontism at the level of the molar in the black Senegalese population 15 to 19 years of age]

This study was done to establish the prevalence of taurodontism using the criteria of SCHIFMAN and CHANANNEL, the first and second molars on the panoramic radiograph of 150 consecutive 15-19 year-old Senegalese people were assessed. Results have shown that taurodontism was present in 48% of patients (18.8% of teeth). Taurodontism was greater in females (% compared % in male) but the difference was not significantly, it was found that was significantly greater in the maxillary and in the second molar.

[Pulmonary manifestations of schistosomiasis]

Bilharziosis or schistosomiasis is the third leading endemic parasitic disease in the world, following malaria and ambiasis. More than 300 million individuals are infested. Schistomosomes are blood flukes which live in the perivisceral veins. Clinical signs result from ova migrations. Transmitted by urine and feces, the parasite cycle requires intermediary host, usually fresh water snails. Bilharsiosis is endemic in tropical zones where it is a major public health problem closely correlated with the socio-economic conditions. Liver, intestinal or urinary complications, depending on the species, lead to underestimated morbidity and mortality. Pulmonary lesions are attributed to 3 species: S. haematobium, S. mansoni and S. japonicum. Although the lung is mandatory step in the parasite cycle, pulmonary manifestations are limited. They can be acute or chronic depending on the phase of the cycle, but are the most frequent extradigestive localization for S. mansoni. Morbidity due to chronic manifestations is particularly severe and should be prevented whenever possible.