Spontaneous nosocomial Proteus mirabilis meningitis in a Human Immunodeficiency Virus (HIV)-infected adult patient: a case report

BACKGROUND

Gram-negative bacillary meningitis remains a rare occurrence, even in patients with human immunodeficiency virus. Current literature only describes anecdotal cases of spontaneous nosocomial Proteus mirabilis meningitis. This report describes the clinical manifestations and management of a patient with healthcare-associated spontaneous Gram-negative bacillary meningitis in a patient with advanced human immunodeficiency virus disease.

CASE PRESENTATION

A 23-year-old Congolese female was hospitalized in a human immunodeficiency virus specialized center for ongoing weight loss, chronic abdominal pain, and vomiting 9 months after initiation of treatment for tuberculosis meningitis. Hospitalization was complicated by healthcare-associated Gram-negative bacillary meningitis on day 18. Blood and cerebrospinal fluid cultures confirmed Proteus mirabilis. Antibiotic susceptibility testing showed extended spectrum beta-lactamase resistant to common antibiotics, and sensitive to meropenem. Despite initiation of high-dose meropenem by intravenous infusion (2 g every 8 hours), the patient did not improve, and died after 4 days of meropenem treatment. Gram-negative bacillary meningitis remains rare and is associated with an unfavorable prognosis.

CONCLUSIONS

This case report highlights the importance of microbiological identification of pathogens in resource-limited settings. As Gram-negative bacillary meningitis does not present with pleocytosis in patients with advanced human immunodeficiency virus, a negative lumbar puncture cannot exclude this diagnosis. Access to clinical bacteriology in resource-limited settings is essential to enable correct antibiotic treatment and avoid overuse of antibiotics to which there is already resistance. It further plays an essential role in public health by identifying antibiotic susceptibilities. Infection prevention and control measures must be reinforced in order to protect patients from such avoidable healthcare-associated infections.

Epidemiology and spatio-temporal distribution of gastrointestinal parasites infection and accuracy of FAMACHA test in sheep in traditional farming systems in Burkina Faso

Blood and faecal samples from 2086 Sahelian and Djallonke sheep have been collected to assess the epidemiology and spatio-temporal distribution of gastrointestinal parasites. A survey with a questionnaire allowed collecting data on individual animal and farms. Faecal samples were analysed using the McMaster technique, while anaemia was assessed using FAMACHA score test and packed cell volume. The overall prevalence of gastrointestinal parasites was 91%, and strongyles (70.7%), Eimeria sp. (60.4%), Moniezia sp. (5.7%), Stronyloides sp. (0.9%) were identified. There was no significant association between the region and strongyles infection (P ˃ 0.05). Animals sampled during the rainy season (n = 565; P = 82.2%, mean EPG = 154.8 ± 12.02) were mostly and heavily infected than those from the hot dry (n = 518; P = 74.2%; mean EPG = 97.7 ± 17.4) and the cold dry season (n = 392; P = 55.5%; mean EPG = 24.5 ± 19.5) (P ˂ 0.05). Females (n = 1027; P = 72.1%; mean EPG = 77.6 ± 17) were most infected than males (n = 448; P = 67.7%; mean EPG = 61.6 ± 19.5) (P ˂ 0.05). Animals that were treated, at most 3 months before sampling (n = 166; P = 61.5%; mean EPG = 41.7 ± 21.4), were less infected than those, which received this treatment after three months before sampling (n = 199; P = 74.8%; mean EPG = 89.1 ± 15.8) (P ˂ 0.05). Data from blood samples indicate that 6.5% of sheep was anaemic (PCV ≤ 19%), while 59.7% was noted anaemic regarding FAMACHA scores. PCV values varied significantly for FAMACHA scores, and the highest mean value was noted for score 1 (27.6) (P ˂ 0.05). The Cohen's kappa score between FAMACHA and PCV was 0.02. These findings suggest that strongyles infections are significantly associated with season, and heavier infections were noted during rainy season.

Spreading of SARS-CoV-2 in West Africa and assessment of risk factors

Although the African continent is, for the moment, less impacted than the rest of the world, it still faces the risk of a spread of COVID-19. In this study, we have conducted a systematic review of the information available in the literature in order to provide an overview of the epidemiological and clinical features of COVID-19 pandemic in West Africa and of the impact of risk factors such as comorbidities, climatic conditions and demography on the pandemic. Burkina Faso is used as a case study to better describe the situation in West Africa. The epidemiological situation of COVID-19 in West Africa is marked by a continuous increase in the numbers of confirmed cases. This geographic area had on 29 July 2020, 131 049 confirmed cases by polymerase chain reaction, 88 305 recoveries and 2102 deaths. Several factors may influence the SARS-CoV-2 circulation in Africa: (i) comorbidities: diabetes mellitus and high blood pressure could lead to an increase in the number of severe cases of SARS-CoV-2; (ii) climatic factors: the high temperatures could be a factor contributing to slow the spread of the virus and (iii) demography: the West Africa population is very young and this could be a factor limiting the occurrence of severe forms of SARS-CoV-2 infection. Although the spread of the SARS-CoV-2 epidemic in West Africa is relatively slow compared to European countries, vigilance must remain. Difficulties in access to diagnostic tests, lack of hospital equipment, but also the large number of people working in the informal sector (such as trading, businesses, transport and restoration) makes it difficult to apply preventive measures, namely physical distancing and containment.

[Xerodermapigmentosum: Challenge of diagnosis in West Africa]

Xeroderma pigmentosum is related to a defect of the enzymes involved in repairing the oncogenic effects of ultraviolet exposure. The condition is found all over the world, in all ethnicities and races. This rare genodermatosis is often unknown in countries lacking specialist in dermatology. This scarcity and insufficiency of qualified personnel give rise to difficulties in diagnosing this pathology, especially in West Africa where XP is wrongly diagnosed for other pathologies. Objective: To share with colleagues the problem of diagnosis of Xeroderma pigmentosum in countries with insufficient number of dermatologist and poor technical platform. Observation: 21-year-old man, with no pathological history of dermatosis was seeking for medical consultation because of cutaneous dryness and photophobia. Previous visits at several health centers failed to diagnose the condition and no noticeable improvement was seen from given treatment. Verbal questioning found the notion of consanguinity (his father and his mother are cousins, and belong to the same Dogon group). Cutaneous pigmentary disorders were absent at birth but appeared at the age of 12 years. Physical examination highlighted photophobia in addition to specific clinical and paraclinical signs allowed to diagnose Xeroderma pigmentosum varying type. Conclusion: in West Africa, the challenge of diagnosis of Xeroderma pigmentosum is undoubtedly related to a lack of qualified personnel and technical means of diagnosis, which makes its frequency underestimated.

[Epidemiological and clinical aspects of prurigo in HIV infected patients in Fousseyni N'Daou hospital of Kayes, Mali]

INTRODUCTION

Prurigo is one of the most common dermatological conditions during HIV infection and AIDS. It appears as an immunosuppression marker associated with HIV infection. The study objective was to determine the prevalence of prurigo in people living with the human immunodeficiency virus (PLHIV) in Fousseyni N'Daou Hospital of Kayes, and to describe the socio-demographic aspects of patients and lesions associated with prurigo among PLHIV.

METHODS

It was a descriptive cross-sectional study included all cases of HIV infected patients with prurigo in the Dermatology-Venomology Department of Fousseyni N'DAOU Hospital from January 1, 2015 to August 31, 2015.

RESULTS

We collected 121 cases of prurigo. The hospital prevalence was 14.5% among PLHIV with 65% Female and the average age was 34.8 years old (SD: 15-81 years). The elementary lesions associated with prurigo were seropapules (40.2%), vesiculo-crusts (13%), excoriated papules (33.3%), lichenified papules (10.8%), and cicatricial lesions (2.7%). The prurigo was generalized in 68.5% of cases and localized in 31.24%. More than half of our patients had weight loss, fever, diarrhea and oral candidiasis in their medical history. Patients were infected with HIV1 in 60.03% and HIV1+ 2 in 24.3%. More than the half of our patients had a CD4 count inferior to 250 cells/mm3 at the time of prurigo diagnosis.

CONCLUSION

In our study, prurigo remains a common condition in PLHIV, particularly in patients with low CD4 counts. Early detection and rapid antietroviral therapy can reduce the frequency of prurigo in PLHIV.

Kaposi's disease in an HIV positive child, with probable contamination from his grandmother

Kaposi's disease in children with HIV is rarely reported in everyday practice. This is a case study of cutaneous Kaposi's disease revealing HIV in a 5-year-old child with polymorphic eruption of papules and nodules on the face, trunk, back, and limbs. Histopathological examination confirmed the diagnosis of Kaposi's disease. The child's HIV serology was positive with a CD4 count of 240/mm³, normochromic and normocytic anemia, and a hemoglobin level at 8.5 g/dl. It was found that the child, after early weaning from his HIV-negative mother, had repeatedly suckled his healthy grandmother, who had no skin lesions but was HIV1 positive. Both grandmother and child were referred for treatment in their locality. The case is noteworthy for the way in which the HIV1 virus infected the child during weaning and then being suckled by his grandmother. The child already had an initial dental flare that could have injured his grandmother. Thus, in our case, there is a contamination by HIV1 virus most likely from the grandmother and contamination by the HHV8 virus, source unidentified as a technical plateau was reached.

[Prevalence of infantile haemangiomas on black skin]

INTRODUCTION

Hemangiomas are regenerative benign vascular tumors of the child, which may be of interest to all organs, most often located on the skin. The aim of our study is to determine the prevalence of haemangiomas on black skin. It is a descriptive cross-sectional study that took place from November 2015 to August 2016 at CNAM, in the department of dermatology-leprology- Venereology of Mali.

RESULTS

Of 14,810 patients seen in consultation, we received 17 cases of hemangioma, ie 0,11%. The average age was 5 months with extremes of 1 month and 60 months. Tuberous angiomas represent 82,35% of clinical forms, subcutaneous angiomas 11,76% and mixed angiomas 5,89%. In 4/17 of our patients there was an infectious complication, following an ulceration on the first day of the consultation. The average lesion size was 3,25cm with extreme 0.5cm and 8cm. The number of lesions per patient was 1 in 16 patients and 2 in 1 patient. In 10/17 patients the lesions were localized at the cephalic level, 3/17 at the trunk level, and 4/17 at the perineum.

CONCLUSION

Infantile hemangioma is a poorly reported condition on black skin. The demands for care are motivated either by the character showing lesions or by ulcerative complications. Sensitization of populations and ongoing training of health workers are needed to detect hemangiomas.

[Risk factors associated with leg erysipelas (cellulitis) in sub-Saharan Africa: A multicentre case-control study]

BACKGROUND

Acute bacterial cellulitis of the leg (erysipelas) is a common problem involving considerable morbidity in dermatology practice in Africa. Previous studies conducted in Europe and North Africa have highlighted lymphoedema and toe-web intertrigo as independent factors associated with leg erysipelas. The aim of this case-control study was to identify risk factors associated with leg erysipelas in sub-Saharan Africa, within a different socio-economic and culture context.

PATIENTS AND METHODS

We conducted a prospective case-control study in hospital dermatology departments in 8 sub-Saharan African countries over a 12-month period (October 2013 to September 2014). Each case of acute leg cellulitis was matched with 2 controls for age (±5 years) and sex. We analysed the general and local factors.

RESULTS

During the study period, 364 cases (223 female, 141 male) were matched with 728 controls. The mean age was 42.15±15.15 years for patients and 42.11±36 years for controls. Multivariate analysis showed the following to be independent risk factors associated with leg erysipelas in our study: obesity (odds ratio [OR]=2.82 ; 95% confidence interval: 2.11-3.76), lymphoedema (OR=3.87, 95%CI: 2.17-6.89), voluntary cosmetic depigmentation (OR=4.29, 95%CI: 2.35-7.83), neglected traumatic wound (OR=37.2, 95%CI: 24.9-57.72) and toe-web intertrigo (OR=37.86, 95%CI: 22.27-64.5).

CONCLUSION

The results of this study confirms the major role of local risk factors (toe-web intertrigo, lymphoedema) previously identified in other geographical settings. However, the originality of our study consists of the identification of voluntary cosmetic depigmentation as a risk factor for leg erysipelas in sub-Saharan Africa.

[Persistent neurological sequelae due to cerebral malaria in a cohort of children from Mali]

INTRODUCTION

Several neurological complications are associated with cerebral malaria (CM). However, few long-term data from childhood survivors have been published.

METHODS

A cross-sectional study was carried out in Mali among children followed from 1999 to 2002 after serious and complicated malaria. Our aim was to evaluate the persistent neurological sequelae associated with CM.

RESULTS

This study concerned 101 subjects who had had CM. Mean age was 5.6+/-3.6 years. Twenty-eight children presented persistent neurological sequelae (27.7p.cent). Among them eight (7.9p.cent) children had developed these sequelae just after CM and 20 (19.8p.cent) a few months later: headaches, mental retardation, speech delay, bucco-facial dyspraxia, diplegia and frontal syndrome (one case each), dystonia (two cases), epilepsy (five cases) and behavior and attention disorders (15 cases).

CONCLUSIONS

In this study, we show that neurological signs due to CM can persist in the long run. Long-term follow-up and proper management after CM are essential.

Preliminary study on immunological and behavioural effects of Thymus broussonetii Boiss., an endemic species in Morocco

In the present work, we had tried to evaluate the immunotropic and behavioural effects of Thymus broussonetii Boiss. So, we tested the neurostimulant effects of four extracts. This preliminary study allowed to identify both the immunostimulant and the neurotropic antistress effects of the studied extracts. Among the four extracts, only the aqueous and ethyl acetate ones showed an apparent effect on the tested biological activities, whereas the butanolic extract and the essential oil did not show any interesting effect (data not shown). These results showed that the aqueous and ethyl extracts of this endemic species are of interest for two reasons: stimulation of the immunizing system and protection against the stress by a neurotropic activity. Thyme extracts increased in vivo the number of leucocyte categories studied including polynuclears, total lymphocytes, TCD4+, TCD8+ and NK cells. These data suggest that the intraperitoneal administration of Thymus broussonetii extract has a potent direct effect on leucocytes in vivo. The elevation of leucocyte and thrombocyte counts produced by thyme in the peripheral blood was already reported in the literature. These results could be of practical importance in the field of phytotherapy in the treatment of some cases of human immunodeficiency such as cancer, leukaemia and AIDS.

Malaria prevention practices in Mopti region, Mali

OBJECTIVES

To assess insecticide-treated nets (ITNs) use, other malaria prevention measures, knowledge of malaria and diffusion of information about ITNs by the National Malaria Control Programme (NMCP) in Mali.

DESIGN

A descriptive cross-sectional study.

SETTING

Four villages in Mopti region, Mali that had participated in the Mopti Regional Malaria Control Program (MRMCP) ITN Education Programme five years prior.

PARTICIPANTS

Three hundred thirty nine randomly-selected households. Within each household, mothers of children one to nine years of age were interviewed regarding knowledge of malaria and prevention practices.

RESULTS

Overall, 11% of households used ITNs, with 97% of these in two villages. Ninety eight percent of households used bednets, 22% used insecticide sprays and 39% used mosquito coils. Significant predictors of ITNs use were: head of household literacy, larger family size, Bambara ethnicity, hearing about the NMCP and hearing about ITNs from health agents. Reasons why ITNs were not used included not knowing anything about ITNs, cost and not having net impregnation services readily available in the village. Levels of knowledge concerning malaria disease, transmission and prevention varied amongst the four villages. ITN households had significantly higher levels of knowledge about malaria and its prevention.

CONCLUSION

Five years after the implementation of the MRMCP, ITNs use was low and diffusion of malaria prevention information was unequal among villages. Future efforts in improving the programme must recognise these differences in knowledge and ITNs utilisation and make village-specific changes that are acceptable for each village.

Efficacy and safety of artemether in the treatment of severe end complicated malaria in mali

We compared the efficacy and safety of artemether versus Quinine in 67 children from 3 months to 15 years old hospitalised for severe and complicated in the pediatric service of Gabriel Touré's Hospital Children were randomised to receive artemether or quinine. Artemether was given at 3,2mg/kg in day 1 (two times) and 1; 6mg single dose from day 2 to day5) and quinine was administrated at 20mg/kg (attack dose) followed by 10mg/kg every 8 hours until oral drug administration (10 mg/kg every 8 hours). The treatment for artemether lasted 5 days while quinine treatment lasted 7 day. Thirty tree and 34 children received respectively artemether and quinine. Two groups were comparable with baseline characteristics. Cerebral malaria was most frequent in the two with no statistical difference. Seventy height percent in artemether group compared to 82,4% in quinine group. No statistical difference was found between groups regarding parameters such as : Parasitic clearance, thermal clearances, delay of exit of the coma, upsurge, tolerance, and mortality. Artemether is as efficacious and well safe as quinine for the treatment of sevese and complicated malaria.

[Evaluation and treatment of snake bites in Bancoumana village in Mali]

A retrospective study was conducted on the epidemiological patterns and treatment of snakebites in the village of Bancoumana, 60 km south-west from Bamako. We analysed a total of 17 cases (8 males and 9 females). The distribution of snakebite cases by gender and by age showed that among subjects aged 5 to 20 years, boys were more exposed than girls (6 vs. 2), whereas, in those of 21 years and above, females were more frequently bitten than males (7 vs. 2) (p = 0.04). The treatment was mainly based on the use of anti-inflammatories and antibiotics, and sometimes of saline, glucose or anti-tetanic serum. Vitamin K was used in 7 cases and no patient was treated specifically. The success of therapy mostly depended on the shortness of delay between the snakebite occurring and patient referral to the health centre, and the low rate of envenomation. All the patients referred the same day they were bitten were cured, whereas three persons referred to the health centre at D3, D7 and D43 after bite died. The surveillance parameters were oedema, bleeding and vomiting.

Effects of prolonged increased intra-abdominal pressure on gastrointestinal blood flow in pigs

BACKGROUND

The aim of the study was to investigate the effects of prolonged intra-abdominal pressure on systemic hemodynamics and gastrointestinal blood circulation.

METHODS

The intra-abdominal pressure in anesthetized pigs was elevated to 20 mmHg (7 animals), 30 mmHg (7 animals), and 40 mmHg (4 animals), respectively. These pressures were maintained for 3 h by intra-abdominal infusion of Ringer's solution. A control group of seven animals had normal intra-abdominal pressure (IAP). Transit time flowmetry and colored microspheres were used to measure blood flow.

RESULTS

An IAP of 20 mmHg did not cause significant changes in systemic hemodynamics or tissue blood flow. An IAP of 30 mmHg caused reduced blood flow in the portal vein, gastric mucosa, small bowel mucosa, pancreas, spleen, and liver. Serum lactate increased in animals with an IAP of 30 mmHg, but microscopy did not disclose mucosal damage in the stomach or small bowel. An IAP of 40 mmHg was followed by severe circulatory changes.

CONCLUSIONS

Prolonged IAP at 20 mmHg did not cause changes in general hemodynamics or gastrointestinal blood flow. Prolonged IAP at 30 mmHg caused reduced portal venous blood flow and reduced tissue flow in various abdominal organs, but no mucosal injury. A prolonged IAP of 40 mmHg represented a dangerous trauma to the animals.

A molecular marker for chloroquine-resistant falciparum malaria

BACKGROUND

Chloroquine-resistant Plasmodium falciparum malaria is a major health problem, particularly in sub-Saharan Africa. Chloroquine resistance has been associated in vitro with point mutations in two genes, pfcrt and pfmdr 1, which encode the P. falciparum digestive-vacuole transmembrane proteins PfCRT and Pgh1, respectively.

METHODS

To assess the value of these mutations as markers for clinical chloroquine resistance, we measured the association between the mutations and the response to chloroquine treatment in patients with uncomplicated falciparum malaria in Mali. The frequencies of the mutations in patients before and after treatment were compared for evidence of selection of resistance factors as a result of exposure to chloroquine.

RESULTS

The pfcrt mutation resulting in the substitution of threonine (T76) for lysine at position 76 was present in all 60 samples from patients with chloroquine-resistant infections (those that persisted or recurred after treatment), as compared with a base-line prevalence of 41 percent in samples obtained before treatment from 116 randomly selected patients (P<0.001), indicating absolute selection for this mutation. The pfmdr 1 mutation resulting in the substitution of tyrosine for asparagine at position 86 was also selected for, since it was present in 48 of 56 post-treatment samples from patients with chloroquine-resistant infections (86 percent), as compared with a base-line prevalence of 50 percent in 115 samples obtained before treatment (P<0.001). The presence of pfcrt T76 was more strongly associated with the development of chloroquine resistance (odds ratio, 18.8; 95 percent confidence interval, 6.5 to 58.3) than was the presence of pfmdr 1 Y86 (odds ratio, 3.2; 95 percent confidence interval, 1.5 to 6.8) or the presence of both mutations (odds ratio, 9.8; 95 percent confidence interval, 4.4 to 22.1).

CONCLUSIONS

This study shows an association between the pfcrt T76 mutation in P. falciparum and the development of chloroquine resistance during the treatment of malaria. This mutation can be used as a marker in surveillance for chloroquine-resistant falciparum malaria.

Effects of boron derivatives on extracellular matrix formation

Boric acid solution (3%) dramatically improves wound healing through action on the extracellular matrix, a finding that has been obtained in vitro. Consequently, investigations are presently underway to produce boronated compounds having a therapeutical effectiveness similar to that of boric acid. On the basis of experimental results obtained with boric acid, we examined the effects of boron derivatives on extracellular matrix formation and degradation and analyzed their potential toxicity by using two biological models (chick embryo cartilage and human fibroblasts). The four boron derivatives tested in this study (triethanolamine borate; N-diethyl-phosphoramidate-propylboronique acid; 2,2 dimethylhexyl-1,3-propanediol-aminopropylboronate and 1,2 propanediol-aminopropylboronate) mimicked the effects of boric acid. They induced a decrease of intracellular concentrations in extracellular matrix macromolecules (proteoglycans, proteins)-associated with an increase of their release in culture medium and stimulated the activity of intra- and extracellular proteases. Similarly to boric acid, these actions occurred after exposure of the cells to concentrations of all boron derivatives without apparent toxic effects. The compounds were found to be more toxic than boric acid itself when concentrations were calculated according to their molecular weight. Nevertheless, these in vitro preliminary results demonstrate effects of boron derivatives that may be of therapeutic benefit in wound repair.

Instruction versus passive observation: a randomized educational research study on laparoscopic suture skills

Implementing laparoscopic surgery is a challenge that should prompt educational research in an attempt to establish a link between instruction and the quality of patient care. This randomized study was undertaken to compare the impact of instruction versus passive observation on laparoscopic skills. The task was stitching and tying a surgeon's knot on a perforated ulcer in a foam stomach placed in a simulator. Outcome measures were accuracy error, goal-directed and non-goal-directed actions, operating time, and tissue damage. Time/motion analysis was carried out by an masked assessor. Twelve participants were well matched for hand-eye coordination at pretesting. Regardless of whether instruction was given or not, a positive correlation was found between overall actions and operating time, non-goal-directed actions and operating time, and overall actions and non-goal directed actions. Intraoperative instruction decreased errors, but this study did not have sufficient power to detect small differences in other outcome measures. The teaching of minimal-access surgery should increasingly be based on educational research data rather than on unstructured rating by attending surgeons.

Effect of dehydroepiandrosterone and its sulfate and fatty acid ester derivatives on rat brain membranes

The effects of dehydroepiandrosterone (DHEA) as well as its sulfate and fatty acid ester derivatives on rat brain membrane fluidity was investigated by fluorescence depolarization of a lipid probe 1,6-diphenyl-1,3,5-hexatriene and compared to its effect on phospholipid conformation investigated by Fourier transform infrared spectroscopy. In rat brain, membrane fluidity varied rostro-caudally, the frontal cortex showing the highest fluidity compared to the hypothalamus, hippocampus, striatum, thalamus, and hindbrain. As previously reported, it was observed that cholesteryl hemisuccinate and stearic acid rigidify striatal membrane whereas linoleic acid and L-alpha-phosphatidylcholine increase the membrane fluidity. Striatal fluidity was increased in vitro with increasing concentrations of DHEA, this effect was greater with the DHEA fatty acid ester derivatives (DHEA-L), DHEA-undecanoate, and DHEA-stearate, whereas no effect was observed with DHEA-sulfate (DHEA-S). In the frontal cortex only the two DHEA-L derivatives increased membrane fluidity, whereas DHEA and DHEA-S were without effect. The effect of DHEA-L on synthetic dimyristoylphosphatidylcholine-d54 phospholipid membranes indicates a disordering effect of DHEA-undecanoate and DHEA-stearate as reflected by increased trans-gauche isomerization of the acyl chains of the lipid. Hence, DHEA-L increase the disorder and/or fluidity of brain membranes; interestingly, these compounds are abundant in the brain where they are generally considered as storage compounds that slowly release the active unconjugated steroid hormone.

Effect of estradiol and tamoxifen on brain membranes: investigation by infrared and fluorescence spectroscopy

Nongenomic effects of steroids on rat brain neurotransmitter transporters and receptors have been reported in several laboratories. In the present study, we have investigated possible membrane effects of 17alpha- and 17beta-estradiol, as well as tamoxifen, by studying their interactions with synthetic phospholipid membranes using Fourier transform infrared spectroscopy. We have also used the fluidity of rat striatal and frontal cortex membranes, as determined by fluorescence depolarization of the probe 1,6-diphenyl-1,3,5-hexatriene (DPH), to probe the effects of these drugs on membranes. Our results show that tamoxifen induces conformational disorder along the acyl chains of deuterated dimirystoylphosphatidylcholine and decreases the gel to liquid-crystalline phase transition temperature by approximately 10 degrees C. Similar effects, although less pronounced, were observed with 17beta-estradiol, whereas 17alpha-estradiol had no significant effect. The DPH fluorescence anisotropy of striatum and frontal cortex membranes was decreased in vitro with 17beta-estradiol or tamoxifen and also with 17alpha-estradiol, but to a lesser extent. These results suggest a stereospecific estradiol effect on membranes and that the effects of these compounds are not related to their activity on estrogen receptors. These observations support a different mechanism of action of steroids that could be implicated in their neuroprotective activity.

Pyrimethamine-sulfadoxine efficacy and selection for mutations in Plasmodium falciparum dihydrofolate reductase and dihydropteroate synthase in Mali

To assess pyrimethamine-sulfadoxine (PS) efficacy in Mali, and the role of mutations in Plasmodium falciparum dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) in in vivo PS resistance, 190 patients with uncomplicated P. falciparum malaria were treated with PS and monitored for 56 days. Mutation-specific polymerase chain reactions and digestion with restriction endonucleases were used to detect DHFR and DHPS mutations on filter paper blood samples from pretreatment and post-treatment infections. Only one case each of RI and RII level resistance and no cases of RIII resistance or therapeutic failure were observed. Post-PS treatment infections had significantly higher rates of DHFR mutations at codons 108 and 59. No significant selection for DHPS mutations was seen. Pyrimethamine-sulfadoxine is highly efficacious in Mali, and while the low level of resistance precludes assessing the utility of molecular assays for in vivo PS resistance, rapid selection of DHFR mutations supports their role in PS failure.

Use of antimalarial drugs in Mali: policy versus reality

Inappropriate use of antimalarial drugs undermines therapeutic efficacy and promotes the emergence and spread of drug-resistant malaria. Strategies for improving compliance require accurate information about current practices. Here we describe Knowledge-Attitude-Practice surveys conducted among health providers and consumers in two Malian villages, one rural and one periurban. All sanctioned providers limited their first choices of antimalarial drug to those recommended by the national malaria control program and reported using correct dosing regimens. However, the majority of consumers in the two villages chose non-recommended treatments for malaria and reported suboptimal treatment regimens when they did use recommended drugs. Antimalarial drugs were also widely available from unsanctioned sources, often accompanied by erroneous advice on dosing regimens. This study demonstrates that even when the most peripheral health providers are well-trained in correct use of antimalarial drugs, additional measures directly targeting consumers will be required to improve drug use practices.

In vivo and in vitro effects of boron and boronated compounds

Boron is ubiquitously present in soils and water. Associated with pectin it is essential for vascular plants as a component of cell walls, and it stabilizes cell membranes. It is required for the growth of pollen tubes and is involved in membrane transport, stimulating H(+)-pumping ATPase activity and K+ uptake. However, a high boron concentration in the soils is toxic to plants and some boronated derivatives are used as herbicides. An absolute requirement for boron has not been definitively demonstrated in animals and humans. However, experiments with boron supplementation or deprivation show that boron is involved in calcium and bone metabolism, and its effects are more marked when other nutrients (cholecalciferol, magnesium) are deficient. Boron supplementation increases the serum concentration of 17 beta-estradiol and testosterone but boron excess has toxic effects on reproductive function. Boron may be involved in cerebral function via its effects on the transport across membranes. It affects the synthesis of the extracellular matrix and is beneficial in wound healing. Usual dietary boron consumption in humans is 1-2 mg/day for adults. As boron has been shown to have biological activity, research into the chemistry of boronated compounds has increased. Boronated compounds have been shown to be potent anti-osteoporotic, anti-inflammatory, hypolipemic, anti-coagulant and anti-neoplastic agents both in vitro and in vivo in animals.

Interaction of dehydroepiandrosterone with phospholipid membranes: an infrared spectroscopy investigation

The interaction between dehydroepiandrosterone (DHEA) and its sulfate metabolite (DHEA-S) with deuterated dimirystoylphosphatidylcholine (DMPC-d54) was investigated by FTIR spectroscopy. DHEA, as cholesterol, induces some conformational order in the liquid-crystalline phase of DMPC-d54. Attenuated total reflectance (ATR) measurements performed on oriented DMPC-d54/steroids samples have shown that in the gel phase, the acyl chains of DMPC-d54 become more normal to the bilayer surface in the presence of DHEA or cholesterol. On the other hand, DHEA-S increases the number of gauche conformers along the hydrocarbon chains of DMPC-d54. No evidence for the presence of hydrogen bond was found between both steroids and the 13C labeled carbonyl group of hydrated DMPC.

A comparison of the incidence of severe malaria in Malian children with normal and C-trait hemoglobin profiles

Although a protective effect against malaria has been demonstrated for several hemoglobin variants, no selective factor is established for the high incidence of HbC in regions of West Africa. Here we report a survey of hemoglobin profiles among children admitted with symptomatic and severe malaria to the Gabriel Touré Hospital in Bamako, Mali, where the frequency of the HbC gene is 8-10%. Children with AC and AA profiles presented with severe malaria at comparable rates, indicating lack of protection by the heterozygous state. Two admitted children, one of whom presented with cerebral malaria, were found to have SC profiles. No CC homozygotes were detected in the study cohort.

Seasonality and malaria in a west African village: does high parasite density predict fever incidence?

In this cohort study, the authors studied the effect of blood malaria parasite density on fever incidence in children in an endemic area with 9 days' follow-up of 1- to 12-year-old children during two time periods: the end of the dry season (May 1993: n = 783) and the end of the rainy season (October 1993: n = 841) in Bougoula, West Africa (region of Sikasso, Mali). The cumulative incidence of fever (temperature > 38.0 degrees C) was 2.0% in the dry season and 8.2% in the rainy season (p < 0.0001). In the rainy season, the risk of fever was increased in children of ages 1-3 years (relative risk (RR) = 2.5, 95% confidence interval (CI) 1.6-4.1); in those with an initial parasitemia > 15,000/microliter (RR = 2.7, 95% CI 1.4-5.4); in children with an enlarged spleen (RR = 2.0, 95% CI 1.2-3.3); or in those with anemia (hematocrit < 30%: RR = 1.8, 95% CI 1.1-2.9). In the dry season, anemia was the only predictor of fever incidence. In the rainy season, the best predictors of fever were, in order, age (< 4 years), enlarged spleen, and high parasite density. Even in the higher risk groups, the cumulative incidence was < 20%. The authors conclude that most children with high parasite density do not develop fever subsequently. The association between parasite density and fever varies according to age and season. Since even high levels of parasite density do not reliably predict fever incidence, parasite density should be considered as just one of a group of indicators that increase the probability of a fever of malarial origin.